1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2014 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22 /* Known bugs or deficiencies include:
23
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
26
27 #include "config.h"
28 #include "system.h"
29 #include "coretypes.h"
30 #include "tm.h"
31 #include "tree.h"
32 #include "stringpool.h"
33 #include "varasm.h"
34 #include "attribs.h"
35 #include "stor-layout.h"
36 #include "intl.h"
37 #include "pointer-set.h"
38 #include "flags.h"
39 #include "cp-tree.h"
40 #include "c-family/c-common.h"
41 #include "c-family/c-objc.h"
42 #include "cp-objcp-common.h"
43 #include "tree-inline.h"
44 #include "decl.h"
45 #include "toplev.h"
46 #include "timevar.h"
47 #include "tree-iterator.h"
48 #include "type-utils.h"
49 #include "gimplify.h"
50
51 /* The type of functions taking a tree, and some additional data, and
52 returning an int. */
53 typedef int (*tree_fn_t) (tree, void*);
54
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
58 struct GTY ((chain_next ("%h.next"))) pending_template {
59 struct pending_template *next;
60 struct tinst_level *tinst;
61 };
62
63 static GTY(()) struct pending_template *pending_templates;
64 static GTY(()) struct pending_template *last_pending_template;
65
66 int processing_template_parmlist;
67 static int template_header_count;
68
69 static GTY(()) tree saved_trees;
70 static vec<int> inline_parm_levels;
71
72 static GTY(()) struct tinst_level *current_tinst_level;
73
74 static GTY(()) tree saved_access_scope;
75
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
79 static tree cur_stmt_expr;
80
81 /* True if we've recursed into fn_type_unification too many times. */
82 static bool excessive_deduction_depth;
83
84 typedef struct GTY(()) spec_entry
85 {
86 tree tmpl;
87 tree args;
88 tree spec;
89 } spec_entry;
90
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
93
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
96
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) vec<tree, va_gc> *canonical_template_parms;
102
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
111
112 enum template_base_result {
113 tbr_incomplete_type,
114 tbr_ambiguous_baseclass,
115 tbr_success
116 };
117
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static bool resolve_overloaded_unification (tree, tree, tree, tree,
121 unification_kind_t, int,
122 bool);
123 static int try_one_overload (tree, tree, tree, tree, tree,
124 unification_kind_t, int, bool, bool);
125 static int unify (tree, tree, tree, tree, int, bool);
126 static void add_pending_template (tree);
127 static tree reopen_tinst_level (struct tinst_level *);
128 static tree tsubst_initializer_list (tree, tree);
129 static tree get_class_bindings (tree, tree, tree, tree);
130 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
131 bool, bool);
132 static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
133 bool, bool);
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
139 tree);
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
142 vec<deferred_access_check, va_gc> **,
143 bool);
144 static void note_template_header (int);
145 static tree convert_nontype_argument_function (tree, tree);
146 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
147 static tree convert_template_argument (tree, tree, tree,
148 tsubst_flags_t, int, tree);
149 static int for_each_template_parm (tree, tree_fn_t, void*,
150 struct pointer_set_t*, bool);
151 static tree expand_template_argument_pack (tree);
152 static tree build_template_parm_index (int, int, int, tree, tree);
153 static bool inline_needs_template_parms (tree, bool);
154 static void push_inline_template_parms_recursive (tree, int);
155 static tree retrieve_local_specialization (tree);
156 static void register_local_specialization (tree, tree);
157 static hashval_t hash_specialization (const void *p);
158 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
159 static int mark_template_parm (tree, void *);
160 static int template_parm_this_level_p (tree, void *);
161 static tree tsubst_friend_function (tree, tree);
162 static tree tsubst_friend_class (tree, tree);
163 static int can_complete_type_without_circularity (tree);
164 static tree get_bindings (tree, tree, tree, bool);
165 static int template_decl_level (tree);
166 static int check_cv_quals_for_unify (int, tree, tree);
167 static void template_parm_level_and_index (tree, int*, int*);
168 static int unify_pack_expansion (tree, tree, tree,
169 tree, unification_kind_t, bool, bool);
170 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
172 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
173 static void regenerate_decl_from_template (tree, tree);
174 static tree most_specialized_class (tree, tsubst_flags_t);
175 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
176 static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree);
177 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
178 static bool check_specialization_scope (void);
179 static tree process_partial_specialization (tree);
180 static void set_current_access_from_decl (tree);
181 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 bool , tree *);
183 static tree try_class_unification (tree, tree, tree, tree, bool);
184 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 tree, tree);
186 static bool template_template_parm_bindings_ok_p (tree, tree);
187 static int template_args_equal (tree, tree);
188 static void tsubst_default_arguments (tree, tsubst_flags_t);
189 static tree for_each_template_parm_r (tree *, int *, void *);
190 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
191 static void copy_default_args_to_explicit_spec (tree);
192 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
202 location_t);
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static tree current_template_args (void);
207 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
208 static tree instantiate_alias_template (tree, tree, tsubst_flags_t);
209
210 /* Make the current scope suitable for access checking when we are
211 processing T. T can be FUNCTION_DECL for instantiated function
212 template, VAR_DECL for static member variable, or TYPE_DECL for
213 alias template (needed by instantiate_decl). */
214
215 static void
push_access_scope(tree t)216 push_access_scope (tree t)
217 {
218 gcc_assert (VAR_OR_FUNCTION_DECL_P (t)
219 || TREE_CODE (t) == TYPE_DECL);
220
221 if (DECL_FRIEND_CONTEXT (t))
222 push_nested_class (DECL_FRIEND_CONTEXT (t));
223 else if (DECL_CLASS_SCOPE_P (t))
224 push_nested_class (DECL_CONTEXT (t));
225 else
226 push_to_top_level ();
227
228 if (TREE_CODE (t) == FUNCTION_DECL)
229 {
230 saved_access_scope = tree_cons
231 (NULL_TREE, current_function_decl, saved_access_scope);
232 current_function_decl = t;
233 }
234 }
235
236 /* Restore the scope set up by push_access_scope. T is the node we
237 are processing. */
238
239 static void
pop_access_scope(tree t)240 pop_access_scope (tree t)
241 {
242 if (TREE_CODE (t) == FUNCTION_DECL)
243 {
244 current_function_decl = TREE_VALUE (saved_access_scope);
245 saved_access_scope = TREE_CHAIN (saved_access_scope);
246 }
247
248 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
249 pop_nested_class ();
250 else
251 pop_from_top_level ();
252 }
253
254 /* Do any processing required when DECL (a member template
255 declaration) is finished. Returns the TEMPLATE_DECL corresponding
256 to DECL, unless it is a specialization, in which case the DECL
257 itself is returned. */
258
259 tree
finish_member_template_decl(tree decl)260 finish_member_template_decl (tree decl)
261 {
262 if (decl == error_mark_node)
263 return error_mark_node;
264
265 gcc_assert (DECL_P (decl));
266
267 if (TREE_CODE (decl) == TYPE_DECL)
268 {
269 tree type;
270
271 type = TREE_TYPE (decl);
272 if (type == error_mark_node)
273 return error_mark_node;
274 if (MAYBE_CLASS_TYPE_P (type)
275 && CLASSTYPE_TEMPLATE_INFO (type)
276 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
277 {
278 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
279 check_member_template (tmpl);
280 return tmpl;
281 }
282 return NULL_TREE;
283 }
284 else if (TREE_CODE (decl) == FIELD_DECL)
285 error ("data member %qD cannot be a member template", decl);
286 else if (DECL_TEMPLATE_INFO (decl))
287 {
288 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
289 {
290 check_member_template (DECL_TI_TEMPLATE (decl));
291 return DECL_TI_TEMPLATE (decl);
292 }
293 else
294 return decl;
295 }
296 else
297 error ("invalid member template declaration %qD", decl);
298
299 return error_mark_node;
300 }
301
302 /* Create a template info node. */
303
304 tree
build_template_info(tree template_decl,tree template_args)305 build_template_info (tree template_decl, tree template_args)
306 {
307 tree result = make_node (TEMPLATE_INFO);
308 TI_TEMPLATE (result) = template_decl;
309 TI_ARGS (result) = template_args;
310 return result;
311 }
312
313 /* Return the template info node corresponding to T, whatever T is. */
314
315 tree
get_template_info(const_tree t)316 get_template_info (const_tree t)
317 {
318 tree tinfo = NULL_TREE;
319
320 if (!t || t == error_mark_node)
321 return NULL;
322
323 if (TREE_CODE (t) == NAMESPACE_DECL)
324 return NULL;
325
326 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
327 tinfo = DECL_TEMPLATE_INFO (t);
328
329 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
330 t = TREE_TYPE (t);
331
332 if (OVERLOAD_TYPE_P (t))
333 tinfo = TYPE_TEMPLATE_INFO (t);
334 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
335 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
336
337 return tinfo;
338 }
339
340 /* Returns the template nesting level of the indicated class TYPE.
341
342 For example, in:
343 template <class T>
344 struct A
345 {
346 template <class U>
347 struct B {};
348 };
349
350 A<T>::B<U> has depth two, while A<T> has depth one.
351 Both A<T>::B<int> and A<int>::B<U> have depth one, if
352 they are instantiations, not specializations.
353
354 This function is guaranteed to return 0 if passed NULL_TREE so
355 that, for example, `template_class_depth (current_class_type)' is
356 always safe. */
357
358 int
template_class_depth(tree type)359 template_class_depth (tree type)
360 {
361 int depth;
362
363 for (depth = 0;
364 type && TREE_CODE (type) != NAMESPACE_DECL;
365 type = (TREE_CODE (type) == FUNCTION_DECL)
366 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 {
368 tree tinfo = get_template_info (type);
369
370 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
371 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
372 ++depth;
373 }
374
375 return depth;
376 }
377
378 /* Subroutine of maybe_begin_member_template_processing.
379 Returns true if processing DECL needs us to push template parms. */
380
381 static bool
inline_needs_template_parms(tree decl,bool nsdmi)382 inline_needs_template_parms (tree decl, bool nsdmi)
383 {
384 if (!decl || (!nsdmi && ! DECL_TEMPLATE_INFO (decl)))
385 return false;
386
387 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
388 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
389 }
390
391 /* Subroutine of maybe_begin_member_template_processing.
392 Push the template parms in PARMS, starting from LEVELS steps into the
393 chain, and ending at the beginning, since template parms are listed
394 innermost first. */
395
396 static void
push_inline_template_parms_recursive(tree parmlist,int levels)397 push_inline_template_parms_recursive (tree parmlist, int levels)
398 {
399 tree parms = TREE_VALUE (parmlist);
400 int i;
401
402 if (levels > 1)
403 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404
405 ++processing_template_decl;
406 current_template_parms
407 = tree_cons (size_int (processing_template_decl),
408 parms, current_template_parms);
409 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410
411 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 NULL);
413 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 {
415 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416
417 if (error_operand_p (parm))
418 continue;
419
420 gcc_assert (DECL_P (parm));
421
422 switch (TREE_CODE (parm))
423 {
424 case TYPE_DECL:
425 case TEMPLATE_DECL:
426 pushdecl (parm);
427 break;
428
429 case PARM_DECL:
430 {
431 /* Make a CONST_DECL as is done in process_template_parm.
432 It is ugly that we recreate this here; the original
433 version built in process_template_parm is no longer
434 available. */
435 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
436 CONST_DECL, DECL_NAME (parm),
437 TREE_TYPE (parm));
438 DECL_ARTIFICIAL (decl) = 1;
439 TREE_CONSTANT (decl) = 1;
440 TREE_READONLY (decl) = 1;
441 DECL_INITIAL (decl) = DECL_INITIAL (parm);
442 SET_DECL_TEMPLATE_PARM_P (decl);
443 pushdecl (decl);
444 }
445 break;
446
447 default:
448 gcc_unreachable ();
449 }
450 }
451 }
452
453 /* Restore the template parameter context for a member template, a
454 friend template defined in a class definition, or a non-template
455 member of template class. */
456
457 void
maybe_begin_member_template_processing(tree decl)458 maybe_begin_member_template_processing (tree decl)
459 {
460 tree parms;
461 int levels = 0;
462 bool nsdmi = TREE_CODE (decl) == FIELD_DECL;
463
464 if (nsdmi)
465 {
466 tree ctx = DECL_CONTEXT (decl);
467 decl = (CLASSTYPE_TEMPLATE_INFO (ctx)
468 /* Disregard full specializations (c++/60999). */
469 && uses_template_parms (ctx)
470 ? CLASSTYPE_TI_TEMPLATE (ctx) : NULL_TREE);
471 }
472
473 if (inline_needs_template_parms (decl, nsdmi))
474 {
475 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
476 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
477
478 if (DECL_TEMPLATE_SPECIALIZATION (decl))
479 {
480 --levels;
481 parms = TREE_CHAIN (parms);
482 }
483
484 push_inline_template_parms_recursive (parms, levels);
485 }
486
487 /* Remember how many levels of template parameters we pushed so that
488 we can pop them later. */
489 inline_parm_levels.safe_push (levels);
490 }
491
492 /* Undo the effects of maybe_begin_member_template_processing. */
493
494 void
maybe_end_member_template_processing(void)495 maybe_end_member_template_processing (void)
496 {
497 int i;
498 int last;
499
500 if (inline_parm_levels.length () == 0)
501 return;
502
503 last = inline_parm_levels.pop ();
504 for (i = 0; i < last; ++i)
505 {
506 --processing_template_decl;
507 current_template_parms = TREE_CHAIN (current_template_parms);
508 poplevel (0, 0, 0);
509 }
510 }
511
512 /* Return a new template argument vector which contains all of ARGS,
513 but has as its innermost set of arguments the EXTRA_ARGS. */
514
515 static tree
add_to_template_args(tree args,tree extra_args)516 add_to_template_args (tree args, tree extra_args)
517 {
518 tree new_args;
519 int extra_depth;
520 int i;
521 int j;
522
523 if (args == NULL_TREE || extra_args == error_mark_node)
524 return extra_args;
525
526 extra_depth = TMPL_ARGS_DEPTH (extra_args);
527 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
528
529 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
530 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
531
532 for (j = 1; j <= extra_depth; ++j, ++i)
533 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
534
535 return new_args;
536 }
537
538 /* Like add_to_template_args, but only the outermost ARGS are added to
539 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
540 (EXTRA_ARGS) levels are added. This function is used to combine
541 the template arguments from a partial instantiation with the
542 template arguments used to attain the full instantiation from the
543 partial instantiation. */
544
545 static tree
add_outermost_template_args(tree args,tree extra_args)546 add_outermost_template_args (tree args, tree extra_args)
547 {
548 tree new_args;
549
550 /* If there are more levels of EXTRA_ARGS than there are ARGS,
551 something very fishy is going on. */
552 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
553
554 /* If *all* the new arguments will be the EXTRA_ARGS, just return
555 them. */
556 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
557 return extra_args;
558
559 /* For the moment, we make ARGS look like it contains fewer levels. */
560 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
561
562 new_args = add_to_template_args (args, extra_args);
563
564 /* Now, we restore ARGS to its full dimensions. */
565 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
566
567 return new_args;
568 }
569
570 /* Return the N levels of innermost template arguments from the ARGS. */
571
572 tree
get_innermost_template_args(tree args,int n)573 get_innermost_template_args (tree args, int n)
574 {
575 tree new_args;
576 int extra_levels;
577 int i;
578
579 gcc_assert (n >= 0);
580
581 /* If N is 1, just return the innermost set of template arguments. */
582 if (n == 1)
583 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
584
585 /* If we're not removing anything, just return the arguments we were
586 given. */
587 extra_levels = TMPL_ARGS_DEPTH (args) - n;
588 gcc_assert (extra_levels >= 0);
589 if (extra_levels == 0)
590 return args;
591
592 /* Make a new set of arguments, not containing the outer arguments. */
593 new_args = make_tree_vec (n);
594 for (i = 1; i <= n; ++i)
595 SET_TMPL_ARGS_LEVEL (new_args, i,
596 TMPL_ARGS_LEVEL (args, i + extra_levels));
597
598 return new_args;
599 }
600
601 /* The inverse of get_innermost_template_args: Return all but the innermost
602 EXTRA_LEVELS levels of template arguments from the ARGS. */
603
604 static tree
strip_innermost_template_args(tree args,int extra_levels)605 strip_innermost_template_args (tree args, int extra_levels)
606 {
607 tree new_args;
608 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
609 int i;
610
611 gcc_assert (n >= 0);
612
613 /* If N is 1, just return the outermost set of template arguments. */
614 if (n == 1)
615 return TMPL_ARGS_LEVEL (args, 1);
616
617 /* If we're not removing anything, just return the arguments we were
618 given. */
619 gcc_assert (extra_levels >= 0);
620 if (extra_levels == 0)
621 return args;
622
623 /* Make a new set of arguments, not containing the inner arguments. */
624 new_args = make_tree_vec (n);
625 for (i = 1; i <= n; ++i)
626 SET_TMPL_ARGS_LEVEL (new_args, i,
627 TMPL_ARGS_LEVEL (args, i));
628
629 return new_args;
630 }
631
632 /* We've got a template header coming up; push to a new level for storing
633 the parms. */
634
635 void
begin_template_parm_list(void)636 begin_template_parm_list (void)
637 {
638 /* We use a non-tag-transparent scope here, which causes pushtag to
639 put tags in this scope, rather than in the enclosing class or
640 namespace scope. This is the right thing, since we want
641 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
642 global template class, push_template_decl handles putting the
643 TEMPLATE_DECL into top-level scope. For a nested template class,
644 e.g.:
645
646 template <class T> struct S1 {
647 template <class T> struct S2 {};
648 };
649
650 pushtag contains special code to call pushdecl_with_scope on the
651 TEMPLATE_DECL for S2. */
652 begin_scope (sk_template_parms, NULL);
653 ++processing_template_decl;
654 ++processing_template_parmlist;
655 note_template_header (0);
656 }
657
658 /* This routine is called when a specialization is declared. If it is
659 invalid to declare a specialization here, an error is reported and
660 false is returned, otherwise this routine will return true. */
661
662 static bool
check_specialization_scope(void)663 check_specialization_scope (void)
664 {
665 tree scope = current_scope ();
666
667 /* [temp.expl.spec]
668
669 An explicit specialization shall be declared in the namespace of
670 which the template is a member, or, for member templates, in the
671 namespace of which the enclosing class or enclosing class
672 template is a member. An explicit specialization of a member
673 function, member class or static data member of a class template
674 shall be declared in the namespace of which the class template
675 is a member. */
676 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
677 {
678 error ("explicit specialization in non-namespace scope %qD", scope);
679 return false;
680 }
681
682 /* [temp.expl.spec]
683
684 In an explicit specialization declaration for a member of a class
685 template or a member template that appears in namespace scope,
686 the member template and some of its enclosing class templates may
687 remain unspecialized, except that the declaration shall not
688 explicitly specialize a class member template if its enclosing
689 class templates are not explicitly specialized as well. */
690 if (current_template_parms)
691 {
692 error ("enclosing class templates are not explicitly specialized");
693 return false;
694 }
695
696 return true;
697 }
698
699 /* We've just seen template <>. */
700
701 bool
begin_specialization(void)702 begin_specialization (void)
703 {
704 begin_scope (sk_template_spec, NULL);
705 note_template_header (1);
706 return check_specialization_scope ();
707 }
708
709 /* Called at then end of processing a declaration preceded by
710 template<>. */
711
712 void
end_specialization(void)713 end_specialization (void)
714 {
715 finish_scope ();
716 reset_specialization ();
717 }
718
719 /* Any template <>'s that we have seen thus far are not referring to a
720 function specialization. */
721
722 void
reset_specialization(void)723 reset_specialization (void)
724 {
725 processing_specialization = 0;
726 template_header_count = 0;
727 }
728
729 /* We've just seen a template header. If SPECIALIZATION is nonzero,
730 it was of the form template <>. */
731
732 static void
note_template_header(int specialization)733 note_template_header (int specialization)
734 {
735 processing_specialization = specialization;
736 template_header_count++;
737 }
738
739 /* We're beginning an explicit instantiation. */
740
741 void
begin_explicit_instantiation(void)742 begin_explicit_instantiation (void)
743 {
744 gcc_assert (!processing_explicit_instantiation);
745 processing_explicit_instantiation = true;
746 }
747
748
749 void
end_explicit_instantiation(void)750 end_explicit_instantiation (void)
751 {
752 gcc_assert (processing_explicit_instantiation);
753 processing_explicit_instantiation = false;
754 }
755
756 /* An explicit specialization or partial specialization of TMPL is being
757 declared. Check that the namespace in which the specialization is
758 occurring is permissible. Returns false iff it is invalid to
759 specialize TMPL in the current namespace. */
760
761 static bool
check_specialization_namespace(tree tmpl)762 check_specialization_namespace (tree tmpl)
763 {
764 tree tpl_ns = decl_namespace_context (tmpl);
765
766 /* [tmpl.expl.spec]
767
768 An explicit specialization shall be declared in the namespace of
769 which the template is a member, or, for member templates, in the
770 namespace of which the enclosing class or enclosing class
771 template is a member. An explicit specialization of a member
772 function, member class or static data member of a class template
773 shall be declared in the namespace of which the class template is
774 a member. */
775 if (current_scope() != DECL_CONTEXT (tmpl)
776 && !at_namespace_scope_p ())
777 {
778 error ("specialization of %qD must appear at namespace scope", tmpl);
779 return false;
780 }
781 if (is_associated_namespace (current_namespace, tpl_ns))
782 /* Same or super-using namespace. */
783 return true;
784 else
785 {
786 permerror (input_location, "specialization of %qD in different namespace", tmpl);
787 permerror (input_location, " from definition of %q+#D", tmpl);
788 return false;
789 }
790 }
791
792 /* SPEC is an explicit instantiation. Check that it is valid to
793 perform this explicit instantiation in the current namespace. */
794
795 static void
check_explicit_instantiation_namespace(tree spec)796 check_explicit_instantiation_namespace (tree spec)
797 {
798 tree ns;
799
800 /* DR 275: An explicit instantiation shall appear in an enclosing
801 namespace of its template. */
802 ns = decl_namespace_context (spec);
803 if (!is_ancestor (current_namespace, ns))
804 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
805 "(which does not enclose namespace %qD)",
806 spec, current_namespace, ns);
807 }
808
809 /* The TYPE is being declared. If it is a template type, that means it
810 is a partial specialization. Do appropriate error-checking. */
811
812 tree
maybe_process_partial_specialization(tree type)813 maybe_process_partial_specialization (tree type)
814 {
815 tree context;
816
817 if (type == error_mark_node)
818 return error_mark_node;
819
820 /* A lambda that appears in specialization context is not itself a
821 specialization. */
822 if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
823 return type;
824
825 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
826 {
827 error ("name of class shadows template template parameter %qD",
828 TYPE_NAME (type));
829 return error_mark_node;
830 }
831
832 context = TYPE_CONTEXT (type);
833
834 if (TYPE_ALIAS_P (type))
835 {
836 if (TYPE_TEMPLATE_INFO (type)
837 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
838 error ("specialization of alias template %qD",
839 TYPE_TI_TEMPLATE (type));
840 else
841 error ("explicit specialization of non-template %qT", type);
842 return error_mark_node;
843 }
844 else if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
845 {
846 /* This is for ordinary explicit specialization and partial
847 specialization of a template class such as:
848
849 template <> class C<int>;
850
851 or:
852
853 template <class T> class C<T*>;
854
855 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
856
857 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
858 && !COMPLETE_TYPE_P (type))
859 {
860 if (!check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type))
861 && !at_namespace_scope_p ())
862 return error_mark_node;
863 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
864 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
865 if (processing_template_decl)
866 {
867 if (push_template_decl (TYPE_MAIN_DECL (type))
868 == error_mark_node)
869 return error_mark_node;
870 }
871 }
872 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
873 error ("specialization of %qT after instantiation", type);
874 else if (errorcount && !processing_specialization
875 && CLASSTYPE_TEMPLATE_SPECIALIZATION (type)
876 && !uses_template_parms (CLASSTYPE_TI_ARGS (type)))
877 /* Trying to define a specialization either without a template<> header
878 or in an inappropriate place. We've already given an error, so just
879 bail now so we don't actually define the specialization. */
880 return error_mark_node;
881 }
882 else if (CLASS_TYPE_P (type)
883 && !CLASSTYPE_USE_TEMPLATE (type)
884 && CLASSTYPE_TEMPLATE_INFO (type)
885 && context && CLASS_TYPE_P (context)
886 && CLASSTYPE_TEMPLATE_INFO (context))
887 {
888 /* This is for an explicit specialization of member class
889 template according to [temp.expl.spec/18]:
890
891 template <> template <class U> class C<int>::D;
892
893 The context `C<int>' must be an implicit instantiation.
894 Otherwise this is just a member class template declared
895 earlier like:
896
897 template <> class C<int> { template <class U> class D; };
898 template <> template <class U> class C<int>::D;
899
900 In the first case, `C<int>::D' is a specialization of `C<T>::D'
901 while in the second case, `C<int>::D' is a primary template
902 and `C<T>::D' may not exist. */
903
904 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
905 && !COMPLETE_TYPE_P (type))
906 {
907 tree t;
908 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
909
910 if (current_namespace
911 != decl_namespace_context (tmpl))
912 {
913 permerror (input_location, "specializing %q#T in different namespace", type);
914 permerror (input_location, " from definition of %q+#D", tmpl);
915 }
916
917 /* Check for invalid specialization after instantiation:
918
919 template <> template <> class C<int>::D<int>;
920 template <> template <class U> class C<int>::D; */
921
922 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
923 t; t = TREE_CHAIN (t))
924 {
925 tree inst = TREE_VALUE (t);
926 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst)
927 || !COMPLETE_OR_OPEN_TYPE_P (inst))
928 {
929 /* We already have a full specialization of this partial
930 instantiation, or a full specialization has been
931 looked up but not instantiated. Reassign it to the
932 new member specialization template. */
933 spec_entry elt;
934 spec_entry *entry;
935 void **slot;
936
937 elt.tmpl = most_general_template (tmpl);
938 elt.args = CLASSTYPE_TI_ARGS (inst);
939 elt.spec = inst;
940
941 htab_remove_elt (type_specializations, &elt);
942
943 elt.tmpl = tmpl;
944 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
945
946 slot = htab_find_slot (type_specializations, &elt, INSERT);
947 entry = ggc_alloc_spec_entry ();
948 *entry = elt;
949 *slot = entry;
950 }
951 else
952 /* But if we've had an implicit instantiation, that's a
953 problem ([temp.expl.spec]/6). */
954 error ("specialization %qT after instantiation %qT",
955 type, inst);
956 }
957
958 /* Mark TYPE as a specialization. And as a result, we only
959 have one level of template argument for the innermost
960 class template. */
961 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
962 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
963 CLASSTYPE_TI_ARGS (type)
964 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
965 }
966 }
967 else if (processing_specialization)
968 {
969 /* Someday C++0x may allow for enum template specialization. */
970 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
971 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
972 pedwarn (input_location, OPT_Wpedantic, "template specialization "
973 "of %qD not allowed by ISO C++", type);
974 else
975 {
976 error ("explicit specialization of non-template %qT", type);
977 return error_mark_node;
978 }
979 }
980
981 return type;
982 }
983
984 /* Returns nonzero if we can optimize the retrieval of specializations
985 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
986 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
987
988 static inline bool
optimize_specialization_lookup_p(tree tmpl)989 optimize_specialization_lookup_p (tree tmpl)
990 {
991 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
992 && DECL_CLASS_SCOPE_P (tmpl)
993 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
994 parameter. */
995 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
996 /* The optimized lookup depends on the fact that the
997 template arguments for the member function template apply
998 purely to the containing class, which is not true if the
999 containing class is an explicit or partial
1000 specialization. */
1001 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
1002 && !DECL_MEMBER_TEMPLATE_P (tmpl)
1003 && !DECL_CONV_FN_P (tmpl)
1004 /* It is possible to have a template that is not a member
1005 template and is not a member of a template class:
1006
1007 template <typename T>
1008 struct S { friend A::f(); };
1009
1010 Here, the friend function is a template, but the context does
1011 not have template information. The optimized lookup relies
1012 on having ARGS be the template arguments for both the class
1013 and the function template. */
1014 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
1015 }
1016
1017 /* Retrieve the specialization (in the sense of [temp.spec] - a
1018 specialization is either an instantiation or an explicit
1019 specialization) of TMPL for the given template ARGS. If there is
1020 no such specialization, return NULL_TREE. The ARGS are a vector of
1021 arguments, or a vector of vectors of arguments, in the case of
1022 templates with more than one level of parameters.
1023
1024 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1025 then we search for a partial specialization matching ARGS. This
1026 parameter is ignored if TMPL is not a class template.
1027
1028 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1029 result is a NONTYPE_ARGUMENT_PACK. */
1030
1031 static tree
retrieve_specialization(tree tmpl,tree args,hashval_t hash)1032 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1033 {
1034 if (tmpl == NULL_TREE)
1035 return NULL_TREE;
1036
1037 if (args == error_mark_node)
1038 return NULL_TREE;
1039
1040 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL
1041 || TREE_CODE (tmpl) == FIELD_DECL);
1042
1043 /* There should be as many levels of arguments as there are
1044 levels of parameters. */
1045 gcc_assert (TMPL_ARGS_DEPTH (args)
1046 == (TREE_CODE (tmpl) == TEMPLATE_DECL
1047 ? TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl))
1048 : template_class_depth (DECL_CONTEXT (tmpl))));
1049
1050 if (optimize_specialization_lookup_p (tmpl))
1051 {
1052 tree class_template;
1053 tree class_specialization;
1054 vec<tree, va_gc> *methods;
1055 tree fns;
1056 int idx;
1057
1058 /* The template arguments actually apply to the containing
1059 class. Find the class specialization with those
1060 arguments. */
1061 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1062 class_specialization
1063 = retrieve_specialization (class_template, args, 0);
1064 if (!class_specialization)
1065 return NULL_TREE;
1066 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1067 for the specialization. */
1068 idx = class_method_index_for_fn (class_specialization, tmpl);
1069 if (idx == -1)
1070 return NULL_TREE;
1071 /* Iterate through the methods with the indicated name, looking
1072 for the one that has an instance of TMPL. */
1073 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1074 for (fns = (*methods)[idx]; fns; fns = OVL_NEXT (fns))
1075 {
1076 tree fn = OVL_CURRENT (fns);
1077 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1078 /* using-declarations can add base methods to the method vec,
1079 and we don't want those here. */
1080 && DECL_CONTEXT (fn) == class_specialization)
1081 return fn;
1082 }
1083 return NULL_TREE;
1084 }
1085 else
1086 {
1087 spec_entry *found;
1088 spec_entry elt;
1089 htab_t specializations;
1090
1091 elt.tmpl = tmpl;
1092 elt.args = args;
1093 elt.spec = NULL_TREE;
1094
1095 if (DECL_CLASS_TEMPLATE_P (tmpl))
1096 specializations = type_specializations;
1097 else
1098 specializations = decl_specializations;
1099
1100 if (hash == 0)
1101 hash = hash_specialization (&elt);
1102 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1103 if (found)
1104 return found->spec;
1105 }
1106
1107 return NULL_TREE;
1108 }
1109
1110 /* Like retrieve_specialization, but for local declarations. */
1111
1112 static tree
retrieve_local_specialization(tree tmpl)1113 retrieve_local_specialization (tree tmpl)
1114 {
1115 void **slot;
1116
1117 if (local_specializations == NULL)
1118 return NULL_TREE;
1119
1120 slot = pointer_map_contains (local_specializations, tmpl);
1121 return slot ? (tree) *slot : NULL_TREE;
1122 }
1123
1124 /* Returns nonzero iff DECL is a specialization of TMPL. */
1125
1126 int
is_specialization_of(tree decl,tree tmpl)1127 is_specialization_of (tree decl, tree tmpl)
1128 {
1129 tree t;
1130
1131 if (TREE_CODE (decl) == FUNCTION_DECL)
1132 {
1133 for (t = decl;
1134 t != NULL_TREE;
1135 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1136 if (t == tmpl)
1137 return 1;
1138 }
1139 else
1140 {
1141 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1142
1143 for (t = TREE_TYPE (decl);
1144 t != NULL_TREE;
1145 t = CLASSTYPE_USE_TEMPLATE (t)
1146 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1147 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1148 return 1;
1149 }
1150
1151 return 0;
1152 }
1153
1154 /* Returns nonzero iff DECL is a specialization of friend declaration
1155 FRIEND_DECL according to [temp.friend]. */
1156
1157 bool
is_specialization_of_friend(tree decl,tree friend_decl)1158 is_specialization_of_friend (tree decl, tree friend_decl)
1159 {
1160 bool need_template = true;
1161 int template_depth;
1162
1163 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1164 || TREE_CODE (decl) == TYPE_DECL);
1165
1166 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1167 of a template class, we want to check if DECL is a specialization
1168 if this. */
1169 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1170 && DECL_TEMPLATE_INFO (friend_decl)
1171 && !DECL_USE_TEMPLATE (friend_decl))
1172 {
1173 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1174 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1175 need_template = false;
1176 }
1177 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1178 && !PRIMARY_TEMPLATE_P (friend_decl))
1179 need_template = false;
1180
1181 /* There is nothing to do if this is not a template friend. */
1182 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1183 return false;
1184
1185 if (is_specialization_of (decl, friend_decl))
1186 return true;
1187
1188 /* [temp.friend/6]
1189 A member of a class template may be declared to be a friend of a
1190 non-template class. In this case, the corresponding member of
1191 every specialization of the class template is a friend of the
1192 class granting friendship.
1193
1194 For example, given a template friend declaration
1195
1196 template <class T> friend void A<T>::f();
1197
1198 the member function below is considered a friend
1199
1200 template <> struct A<int> {
1201 void f();
1202 };
1203
1204 For this type of template friend, TEMPLATE_DEPTH below will be
1205 nonzero. To determine if DECL is a friend of FRIEND, we first
1206 check if the enclosing class is a specialization of another. */
1207
1208 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1209 if (template_depth
1210 && DECL_CLASS_SCOPE_P (decl)
1211 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1212 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1213 {
1214 /* Next, we check the members themselves. In order to handle
1215 a few tricky cases, such as when FRIEND_DECL's are
1216
1217 template <class T> friend void A<T>::g(T t);
1218 template <class T> template <T t> friend void A<T>::h();
1219
1220 and DECL's are
1221
1222 void A<int>::g(int);
1223 template <int> void A<int>::h();
1224
1225 we need to figure out ARGS, the template arguments from
1226 the context of DECL. This is required for template substitution
1227 of `T' in the function parameter of `g' and template parameter
1228 of `h' in the above examples. Here ARGS corresponds to `int'. */
1229
1230 tree context = DECL_CONTEXT (decl);
1231 tree args = NULL_TREE;
1232 int current_depth = 0;
1233
1234 while (current_depth < template_depth)
1235 {
1236 if (CLASSTYPE_TEMPLATE_INFO (context))
1237 {
1238 if (current_depth == 0)
1239 args = TYPE_TI_ARGS (context);
1240 else
1241 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1242 current_depth++;
1243 }
1244 context = TYPE_CONTEXT (context);
1245 }
1246
1247 if (TREE_CODE (decl) == FUNCTION_DECL)
1248 {
1249 bool is_template;
1250 tree friend_type;
1251 tree decl_type;
1252 tree friend_args_type;
1253 tree decl_args_type;
1254
1255 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 non-templates. */
1257 is_template = DECL_TEMPLATE_INFO (decl)
1258 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1259 if (need_template ^ is_template)
1260 return false;
1261 else if (is_template)
1262 {
1263 /* If both are templates, check template parameter list. */
1264 tree friend_parms
1265 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1266 args, tf_none);
1267 if (!comp_template_parms
1268 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1269 friend_parms))
1270 return false;
1271
1272 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1273 }
1274 else
1275 decl_type = TREE_TYPE (decl);
1276
1277 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1278 tf_none, NULL_TREE);
1279 if (friend_type == error_mark_node)
1280 return false;
1281
1282 /* Check if return types match. */
1283 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1284 return false;
1285
1286 /* Check if function parameter types match, ignoring the
1287 `this' parameter. */
1288 friend_args_type = TYPE_ARG_TYPES (friend_type);
1289 decl_args_type = TYPE_ARG_TYPES (decl_type);
1290 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1291 friend_args_type = TREE_CHAIN (friend_args_type);
1292 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1293 decl_args_type = TREE_CHAIN (decl_args_type);
1294
1295 return compparms (decl_args_type, friend_args_type);
1296 }
1297 else
1298 {
1299 /* DECL is a TYPE_DECL */
1300 bool is_template;
1301 tree decl_type = TREE_TYPE (decl);
1302
1303 /* Make sure that both DECL and FRIEND_DECL are templates or
1304 non-templates. */
1305 is_template
1306 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1307 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1308
1309 if (need_template ^ is_template)
1310 return false;
1311 else if (is_template)
1312 {
1313 tree friend_parms;
1314 /* If both are templates, check the name of the two
1315 TEMPLATE_DECL's first because is_friend didn't. */
1316 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1317 != DECL_NAME (friend_decl))
1318 return false;
1319
1320 /* Now check template parameter list. */
1321 friend_parms
1322 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1323 args, tf_none);
1324 return comp_template_parms
1325 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1326 friend_parms);
1327 }
1328 else
1329 return (DECL_NAME (decl)
1330 == DECL_NAME (friend_decl));
1331 }
1332 }
1333 return false;
1334 }
1335
1336 /* Register the specialization SPEC as a specialization of TMPL with
1337 the indicated ARGS. IS_FRIEND indicates whether the specialization
1338 is actually just a friend declaration. Returns SPEC, or an
1339 equivalent prior declaration, if available.
1340
1341 We also store instantiations of field packs in the hash table, even
1342 though they are not themselves templates, to make lookup easier. */
1343
1344 static tree
register_specialization(tree spec,tree tmpl,tree args,bool is_friend,hashval_t hash)1345 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1346 hashval_t hash)
1347 {
1348 tree fn;
1349 void **slot = NULL;
1350 spec_entry elt;
1351
1352 gcc_assert ((TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec))
1353 || (TREE_CODE (tmpl) == FIELD_DECL
1354 && TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK));
1355
1356 if (TREE_CODE (spec) == FUNCTION_DECL
1357 && uses_template_parms (DECL_TI_ARGS (spec)))
1358 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1359 register it; we want the corresponding TEMPLATE_DECL instead.
1360 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1361 the more obvious `uses_template_parms (spec)' to avoid problems
1362 with default function arguments. In particular, given
1363 something like this:
1364
1365 template <class T> void f(T t1, T t = T())
1366
1367 the default argument expression is not substituted for in an
1368 instantiation unless and until it is actually needed. */
1369 return spec;
1370
1371 if (optimize_specialization_lookup_p (tmpl))
1372 /* We don't put these specializations in the hash table, but we might
1373 want to give an error about a mismatch. */
1374 fn = retrieve_specialization (tmpl, args, 0);
1375 else
1376 {
1377 elt.tmpl = tmpl;
1378 elt.args = args;
1379 elt.spec = spec;
1380
1381 if (hash == 0)
1382 hash = hash_specialization (&elt);
1383
1384 slot =
1385 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1386 if (*slot)
1387 fn = ((spec_entry *) *slot)->spec;
1388 else
1389 fn = NULL_TREE;
1390 }
1391
1392 /* We can sometimes try to re-register a specialization that we've
1393 already got. In particular, regenerate_decl_from_template calls
1394 duplicate_decls which will update the specialization list. But,
1395 we'll still get called again here anyhow. It's more convenient
1396 to simply allow this than to try to prevent it. */
1397 if (fn == spec)
1398 return spec;
1399 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1400 {
1401 if (DECL_TEMPLATE_INSTANTIATION (fn))
1402 {
1403 if (DECL_ODR_USED (fn)
1404 || DECL_EXPLICIT_INSTANTIATION (fn))
1405 {
1406 error ("specialization of %qD after instantiation",
1407 fn);
1408 return error_mark_node;
1409 }
1410 else
1411 {
1412 tree clone;
1413 /* This situation should occur only if the first
1414 specialization is an implicit instantiation, the
1415 second is an explicit specialization, and the
1416 implicit instantiation has not yet been used. That
1417 situation can occur if we have implicitly
1418 instantiated a member function and then specialized
1419 it later.
1420
1421 We can also wind up here if a friend declaration that
1422 looked like an instantiation turns out to be a
1423 specialization:
1424
1425 template <class T> void foo(T);
1426 class S { friend void foo<>(int) };
1427 template <> void foo(int);
1428
1429 We transform the existing DECL in place so that any
1430 pointers to it become pointers to the updated
1431 declaration.
1432
1433 If there was a definition for the template, but not
1434 for the specialization, we want this to look as if
1435 there were no definition, and vice versa. */
1436 DECL_INITIAL (fn) = NULL_TREE;
1437 duplicate_decls (spec, fn, is_friend);
1438 /* The call to duplicate_decls will have applied
1439 [temp.expl.spec]:
1440
1441 An explicit specialization of a function template
1442 is inline only if it is explicitly declared to be,
1443 and independently of whether its function template
1444 is.
1445
1446 to the primary function; now copy the inline bits to
1447 the various clones. */
1448 FOR_EACH_CLONE (clone, fn)
1449 {
1450 DECL_DECLARED_INLINE_P (clone)
1451 = DECL_DECLARED_INLINE_P (fn);
1452 DECL_SOURCE_LOCATION (clone)
1453 = DECL_SOURCE_LOCATION (fn);
1454 DECL_DELETED_FN (clone)
1455 = DECL_DELETED_FN (fn);
1456 }
1457 check_specialization_namespace (tmpl);
1458
1459 return fn;
1460 }
1461 }
1462 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1463 {
1464 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1465 /* Dup decl failed, but this is a new definition. Set the
1466 line number so any errors match this new
1467 definition. */
1468 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1469
1470 return fn;
1471 }
1472 }
1473 else if (fn)
1474 return duplicate_decls (spec, fn, is_friend);
1475
1476 /* A specialization must be declared in the same namespace as the
1477 template it is specializing. */
1478 if (DECL_P (spec) && DECL_TEMPLATE_SPECIALIZATION (spec)
1479 && !check_specialization_namespace (tmpl))
1480 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1481
1482 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1483 {
1484 spec_entry *entry = ggc_alloc_spec_entry ();
1485 gcc_assert (tmpl && args && spec);
1486 *entry = elt;
1487 *slot = entry;
1488 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1489 && PRIMARY_TEMPLATE_P (tmpl)
1490 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1491 /* TMPL is a forward declaration of a template function; keep a list
1492 of all specializations in case we need to reassign them to a friend
1493 template later in tsubst_friend_function. */
1494 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1495 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1496 }
1497
1498 return spec;
1499 }
1500
1501 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1502 TMPL and ARGS members, ignores SPEC. */
1503
1504 int comparing_specializations;
1505
1506 static int
eq_specializations(const void * p1,const void * p2)1507 eq_specializations (const void *p1, const void *p2)
1508 {
1509 const spec_entry *e1 = (const spec_entry *)p1;
1510 const spec_entry *e2 = (const spec_entry *)p2;
1511 int equal;
1512
1513 ++comparing_specializations;
1514 equal = (e1->tmpl == e2->tmpl
1515 && comp_template_args (e1->args, e2->args));
1516 --comparing_specializations;
1517
1518 return equal;
1519 }
1520
1521 /* Returns a hash for a template TMPL and template arguments ARGS. */
1522
1523 static hashval_t
hash_tmpl_and_args(tree tmpl,tree args)1524 hash_tmpl_and_args (tree tmpl, tree args)
1525 {
1526 hashval_t val = DECL_UID (tmpl);
1527 return iterative_hash_template_arg (args, val);
1528 }
1529
1530 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1531 ignoring SPEC. */
1532
1533 static hashval_t
hash_specialization(const void * p)1534 hash_specialization (const void *p)
1535 {
1536 const spec_entry *e = (const spec_entry *)p;
1537 return hash_tmpl_and_args (e->tmpl, e->args);
1538 }
1539
1540 /* Recursively calculate a hash value for a template argument ARG, for use
1541 in the hash tables of template specializations. */
1542
1543 hashval_t
iterative_hash_template_arg(tree arg,hashval_t val)1544 iterative_hash_template_arg (tree arg, hashval_t val)
1545 {
1546 unsigned HOST_WIDE_INT i;
1547 enum tree_code code;
1548 char tclass;
1549
1550 if (arg == NULL_TREE)
1551 return iterative_hash_object (arg, val);
1552
1553 if (!TYPE_P (arg))
1554 STRIP_NOPS (arg);
1555
1556 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1557 /* We can get one of these when re-hashing a previous entry in the middle
1558 of substituting into a pack expansion. Just look through it. */
1559 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1560
1561 code = TREE_CODE (arg);
1562 tclass = TREE_CODE_CLASS (code);
1563
1564 val = iterative_hash_object (code, val);
1565
1566 switch (code)
1567 {
1568 case ERROR_MARK:
1569 return val;
1570
1571 case IDENTIFIER_NODE:
1572 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1573
1574 case TREE_VEC:
1575 {
1576 int i, len = TREE_VEC_LENGTH (arg);
1577 for (i = 0; i < len; ++i)
1578 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1579 return val;
1580 }
1581
1582 case TYPE_PACK_EXPANSION:
1583 case EXPR_PACK_EXPANSION:
1584 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1585 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1586
1587 case TYPE_ARGUMENT_PACK:
1588 case NONTYPE_ARGUMENT_PACK:
1589 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1590
1591 case TREE_LIST:
1592 for (; arg; arg = TREE_CHAIN (arg))
1593 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1594 return val;
1595
1596 case OVERLOAD:
1597 for (; arg; arg = OVL_NEXT (arg))
1598 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1599 return val;
1600
1601 case CONSTRUCTOR:
1602 {
1603 tree field, value;
1604 iterative_hash_template_arg (TREE_TYPE (arg), val);
1605 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1606 {
1607 val = iterative_hash_template_arg (field, val);
1608 val = iterative_hash_template_arg (value, val);
1609 }
1610 return val;
1611 }
1612
1613 case PARM_DECL:
1614 if (!DECL_ARTIFICIAL (arg))
1615 {
1616 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1617 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1618 }
1619 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1620
1621 case TARGET_EXPR:
1622 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1623
1624 case PTRMEM_CST:
1625 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1626 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1627
1628 case TEMPLATE_PARM_INDEX:
1629 val = iterative_hash_template_arg
1630 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1631 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1632 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1633
1634 case TRAIT_EXPR:
1635 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1636 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1637 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1638
1639 case BASELINK:
1640 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1641 val);
1642 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1643 val);
1644
1645 case MODOP_EXPR:
1646 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1647 code = TREE_CODE (TREE_OPERAND (arg, 1));
1648 val = iterative_hash_object (code, val);
1649 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1650
1651 case LAMBDA_EXPR:
1652 /* A lambda can't appear in a template arg, but don't crash on
1653 erroneous input. */
1654 gcc_assert (seen_error ());
1655 return val;
1656
1657 case CAST_EXPR:
1658 case IMPLICIT_CONV_EXPR:
1659 case STATIC_CAST_EXPR:
1660 case REINTERPRET_CAST_EXPR:
1661 case CONST_CAST_EXPR:
1662 case DYNAMIC_CAST_EXPR:
1663 case NEW_EXPR:
1664 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1665 /* Now hash operands as usual. */
1666 break;
1667
1668 default:
1669 break;
1670 }
1671
1672 switch (tclass)
1673 {
1674 case tcc_type:
1675 if (TYPE_CANONICAL (arg))
1676 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1677 val);
1678 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1679 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1680 /* Otherwise just compare the types during lookup. */
1681 return val;
1682
1683 case tcc_declaration:
1684 case tcc_constant:
1685 return iterative_hash_expr (arg, val);
1686
1687 default:
1688 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1689 {
1690 unsigned n = cp_tree_operand_length (arg);
1691 for (i = 0; i < n; ++i)
1692 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1693 return val;
1694 }
1695 }
1696 gcc_unreachable ();
1697 return 0;
1698 }
1699
1700 /* Unregister the specialization SPEC as a specialization of TMPL.
1701 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1702 if the SPEC was listed as a specialization of TMPL.
1703
1704 Note that SPEC has been ggc_freed, so we can't look inside it. */
1705
1706 bool
reregister_specialization(tree spec,tree tinfo,tree new_spec)1707 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1708 {
1709 spec_entry *entry;
1710 spec_entry elt;
1711
1712 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1713 elt.args = TI_ARGS (tinfo);
1714 elt.spec = NULL_TREE;
1715
1716 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1717 if (entry != NULL)
1718 {
1719 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1720 gcc_assert (new_spec != NULL_TREE);
1721 entry->spec = new_spec;
1722 return 1;
1723 }
1724
1725 return 0;
1726 }
1727
1728 /* Like register_specialization, but for local declarations. We are
1729 registering SPEC, an instantiation of TMPL. */
1730
1731 static void
register_local_specialization(tree spec,tree tmpl)1732 register_local_specialization (tree spec, tree tmpl)
1733 {
1734 void **slot;
1735
1736 slot = pointer_map_insert (local_specializations, tmpl);
1737 *slot = spec;
1738 }
1739
1740 /* TYPE is a class type. Returns true if TYPE is an explicitly
1741 specialized class. */
1742
1743 bool
explicit_class_specialization_p(tree type)1744 explicit_class_specialization_p (tree type)
1745 {
1746 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1747 return false;
1748 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1749 }
1750
1751 /* Print the list of functions at FNS, going through all the overloads
1752 for each element of the list. Alternatively, FNS can not be a
1753 TREE_LIST, in which case it will be printed together with all the
1754 overloads.
1755
1756 MORE and *STR should respectively be FALSE and NULL when the function
1757 is called from the outside. They are used internally on recursive
1758 calls. print_candidates manages the two parameters and leaves NULL
1759 in *STR when it ends. */
1760
1761 static void
print_candidates_1(tree fns,bool more,const char ** str)1762 print_candidates_1 (tree fns, bool more, const char **str)
1763 {
1764 tree fn, fn2;
1765 char *spaces = NULL;
1766
1767 for (fn = fns; fn; fn = OVL_NEXT (fn))
1768 if (TREE_CODE (fn) == TREE_LIST)
1769 {
1770 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1771 print_candidates_1 (TREE_VALUE (fn2),
1772 TREE_CHAIN (fn2) || more, str);
1773 }
1774 else
1775 {
1776 tree cand = OVL_CURRENT (fn);
1777 if (!*str)
1778 {
1779 /* Pick the prefix string. */
1780 if (!more && !OVL_NEXT (fns))
1781 {
1782 inform (DECL_SOURCE_LOCATION (cand),
1783 "candidate is: %#D", cand);
1784 continue;
1785 }
1786
1787 *str = _("candidates are:");
1788 spaces = get_spaces (*str);
1789 }
1790 inform (DECL_SOURCE_LOCATION (cand), "%s %#D", *str, cand);
1791 *str = spaces ? spaces : *str;
1792 }
1793
1794 if (!more)
1795 {
1796 free (spaces);
1797 *str = NULL;
1798 }
1799 }
1800
1801 /* Print the list of candidate FNS in an error message. FNS can also
1802 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1803
1804 void
print_candidates(tree fns)1805 print_candidates (tree fns)
1806 {
1807 const char *str = NULL;
1808 print_candidates_1 (fns, false, &str);
1809 gcc_assert (str == NULL);
1810 }
1811
1812 /* Returns the template (one of the functions given by TEMPLATE_ID)
1813 which can be specialized to match the indicated DECL with the
1814 explicit template args given in TEMPLATE_ID. The DECL may be
1815 NULL_TREE if none is available. In that case, the functions in
1816 TEMPLATE_ID are non-members.
1817
1818 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1819 specialization of a member template.
1820
1821 The TEMPLATE_COUNT is the number of references to qualifying
1822 template classes that appeared in the name of the function. See
1823 check_explicit_specialization for a more accurate description.
1824
1825 TSK indicates what kind of template declaration (if any) is being
1826 declared. TSK_TEMPLATE indicates that the declaration given by
1827 DECL, though a FUNCTION_DECL, has template parameters, and is
1828 therefore a template function.
1829
1830 The template args (those explicitly specified and those deduced)
1831 are output in a newly created vector *TARGS_OUT.
1832
1833 If it is impossible to determine the result, an error message is
1834 issued. The error_mark_node is returned to indicate failure. */
1835
1836 static tree
determine_specialization(tree template_id,tree decl,tree * targs_out,int need_member_template,int template_count,tmpl_spec_kind tsk)1837 determine_specialization (tree template_id,
1838 tree decl,
1839 tree* targs_out,
1840 int need_member_template,
1841 int template_count,
1842 tmpl_spec_kind tsk)
1843 {
1844 tree fns;
1845 tree targs;
1846 tree explicit_targs;
1847 tree candidates = NULL_TREE;
1848 /* A TREE_LIST of templates of which DECL may be a specialization.
1849 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1850 corresponding TREE_PURPOSE is the set of template arguments that,
1851 when used to instantiate the template, would produce a function
1852 with the signature of DECL. */
1853 tree templates = NULL_TREE;
1854 int header_count;
1855 cp_binding_level *b;
1856
1857 *targs_out = NULL_TREE;
1858
1859 if (template_id == error_mark_node || decl == error_mark_node)
1860 return error_mark_node;
1861
1862 /* We shouldn't be specializing a member template of an
1863 unspecialized class template; we already gave an error in
1864 check_specialization_scope, now avoid crashing. */
1865 if (template_count && DECL_CLASS_SCOPE_P (decl)
1866 && template_class_depth (DECL_CONTEXT (decl)) > 0)
1867 {
1868 gcc_assert (errorcount);
1869 return error_mark_node;
1870 }
1871
1872 fns = TREE_OPERAND (template_id, 0);
1873 explicit_targs = TREE_OPERAND (template_id, 1);
1874
1875 if (fns == error_mark_node)
1876 return error_mark_node;
1877
1878 /* Check for baselinks. */
1879 if (BASELINK_P (fns))
1880 fns = BASELINK_FUNCTIONS (fns);
1881
1882 if (!is_overloaded_fn (fns))
1883 {
1884 error ("%qD is not a function template", fns);
1885 return error_mark_node;
1886 }
1887
1888 /* Count the number of template headers specified for this
1889 specialization. */
1890 header_count = 0;
1891 for (b = current_binding_level;
1892 b->kind == sk_template_parms;
1893 b = b->level_chain)
1894 ++header_count;
1895
1896 for (; fns; fns = OVL_NEXT (fns))
1897 {
1898 tree fn = OVL_CURRENT (fns);
1899
1900 if (TREE_CODE (fn) == TEMPLATE_DECL)
1901 {
1902 tree decl_arg_types;
1903 tree fn_arg_types;
1904 tree insttype;
1905
1906 /* In case of explicit specialization, we need to check if
1907 the number of template headers appearing in the specialization
1908 is correct. This is usually done in check_explicit_specialization,
1909 but the check done there cannot be exhaustive when specializing
1910 member functions. Consider the following code:
1911
1912 template <> void A<int>::f(int);
1913 template <> template <> void A<int>::f(int);
1914
1915 Assuming that A<int> is not itself an explicit specialization
1916 already, the first line specializes "f" which is a non-template
1917 member function, whilst the second line specializes "f" which
1918 is a template member function. So both lines are syntactically
1919 correct, and check_explicit_specialization does not reject
1920 them.
1921
1922 Here, we can do better, as we are matching the specialization
1923 against the declarations. We count the number of template
1924 headers, and we check if they match TEMPLATE_COUNT + 1
1925 (TEMPLATE_COUNT is the number of qualifying template classes,
1926 plus there must be another header for the member template
1927 itself).
1928
1929 Notice that if header_count is zero, this is not a
1930 specialization but rather a template instantiation, so there
1931 is no check we can perform here. */
1932 if (header_count && header_count != template_count + 1)
1933 continue;
1934
1935 /* Check that the number of template arguments at the
1936 innermost level for DECL is the same as for FN. */
1937 if (current_binding_level->kind == sk_template_parms
1938 && !current_binding_level->explicit_spec_p
1939 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1940 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1941 (current_template_parms))))
1942 continue;
1943
1944 /* DECL might be a specialization of FN. */
1945 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1946 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1947
1948 /* For a non-static member function, we need to make sure
1949 that the const qualification is the same. Since
1950 get_bindings does not try to merge the "this" parameter,
1951 we must do the comparison explicitly. */
1952 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1953 && !same_type_p (TREE_VALUE (fn_arg_types),
1954 TREE_VALUE (decl_arg_types)))
1955 continue;
1956
1957 /* Skip the "this" parameter and, for constructors of
1958 classes with virtual bases, the VTT parameter. A
1959 full specialization of a constructor will have a VTT
1960 parameter, but a template never will. */
1961 decl_arg_types
1962 = skip_artificial_parms_for (decl, decl_arg_types);
1963 fn_arg_types
1964 = skip_artificial_parms_for (fn, fn_arg_types);
1965
1966 /* Function templates cannot be specializations; there are
1967 no partial specializations of functions. Therefore, if
1968 the type of DECL does not match FN, there is no
1969 match. */
1970 if (tsk == tsk_template)
1971 {
1972 if (compparms (fn_arg_types, decl_arg_types))
1973 candidates = tree_cons (NULL_TREE, fn, candidates);
1974 continue;
1975 }
1976
1977 /* See whether this function might be a specialization of this
1978 template. Suppress access control because we might be trying
1979 to make this specialization a friend, and we have already done
1980 access control for the declaration of the specialization. */
1981 push_deferring_access_checks (dk_no_check);
1982 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1983 pop_deferring_access_checks ();
1984
1985 if (!targs)
1986 /* We cannot deduce template arguments that when used to
1987 specialize TMPL will produce DECL. */
1988 continue;
1989
1990 /* Make sure that the deduced arguments actually work. */
1991 insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
1992 if (insttype == error_mark_node)
1993 continue;
1994 fn_arg_types
1995 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype));
1996 if (!compparms (fn_arg_types, decl_arg_types))
1997 continue;
1998
1999 /* Save this template, and the arguments deduced. */
2000 templates = tree_cons (targs, fn, templates);
2001 }
2002 else if (need_member_template)
2003 /* FN is an ordinary member function, and we need a
2004 specialization of a member template. */
2005 ;
2006 else if (TREE_CODE (fn) != FUNCTION_DECL)
2007 /* We can get IDENTIFIER_NODEs here in certain erroneous
2008 cases. */
2009 ;
2010 else if (!DECL_FUNCTION_MEMBER_P (fn))
2011 /* This is just an ordinary non-member function. Nothing can
2012 be a specialization of that. */
2013 ;
2014 else if (DECL_ARTIFICIAL (fn))
2015 /* Cannot specialize functions that are created implicitly. */
2016 ;
2017 else
2018 {
2019 tree decl_arg_types;
2020
2021 /* This is an ordinary member function. However, since
2022 we're here, we can assume its enclosing class is a
2023 template class. For example,
2024
2025 template <typename T> struct S { void f(); };
2026 template <> void S<int>::f() {}
2027
2028 Here, S<int>::f is a non-template, but S<int> is a
2029 template class. If FN has the same type as DECL, we
2030 might be in business. */
2031
2032 if (!DECL_TEMPLATE_INFO (fn))
2033 /* Its enclosing class is an explicit specialization
2034 of a template class. This is not a candidate. */
2035 continue;
2036
2037 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
2038 TREE_TYPE (TREE_TYPE (fn))))
2039 /* The return types differ. */
2040 continue;
2041
2042 /* Adjust the type of DECL in case FN is a static member. */
2043 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
2044 if (DECL_STATIC_FUNCTION_P (fn)
2045 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2046 decl_arg_types = TREE_CHAIN (decl_arg_types);
2047
2048 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2049 decl_arg_types))
2050 /* They match! */
2051 candidates = tree_cons (NULL_TREE, fn, candidates);
2052 }
2053 }
2054
2055 if (templates && TREE_CHAIN (templates))
2056 {
2057 /* We have:
2058
2059 [temp.expl.spec]
2060
2061 It is possible for a specialization with a given function
2062 signature to be instantiated from more than one function
2063 template. In such cases, explicit specification of the
2064 template arguments must be used to uniquely identify the
2065 function template specialization being specialized.
2066
2067 Note that here, there's no suggestion that we're supposed to
2068 determine which of the candidate templates is most
2069 specialized. However, we, also have:
2070
2071 [temp.func.order]
2072
2073 Partial ordering of overloaded function template
2074 declarations is used in the following contexts to select
2075 the function template to which a function template
2076 specialization refers:
2077
2078 -- when an explicit specialization refers to a function
2079 template.
2080
2081 So, we do use the partial ordering rules, at least for now.
2082 This extension can only serve to make invalid programs valid,
2083 so it's safe. And, there is strong anecdotal evidence that
2084 the committee intended the partial ordering rules to apply;
2085 the EDG front end has that behavior, and John Spicer claims
2086 that the committee simply forgot to delete the wording in
2087 [temp.expl.spec]. */
2088 tree tmpl = most_specialized_instantiation (templates);
2089 if (tmpl != error_mark_node)
2090 {
2091 templates = tmpl;
2092 TREE_CHAIN (templates) = NULL_TREE;
2093 }
2094 }
2095
2096 if (templates == NULL_TREE && candidates == NULL_TREE)
2097 {
2098 error ("template-id %qD for %q+D does not match any template "
2099 "declaration", template_id, decl);
2100 if (header_count && header_count != template_count + 1)
2101 inform (input_location, "saw %d %<template<>%>, need %d for "
2102 "specializing a member function template",
2103 header_count, template_count + 1);
2104 return error_mark_node;
2105 }
2106 else if ((templates && TREE_CHAIN (templates))
2107 || (candidates && TREE_CHAIN (candidates))
2108 || (templates && candidates))
2109 {
2110 error ("ambiguous template specialization %qD for %q+D",
2111 template_id, decl);
2112 candidates = chainon (candidates, templates);
2113 print_candidates (candidates);
2114 return error_mark_node;
2115 }
2116
2117 /* We have one, and exactly one, match. */
2118 if (candidates)
2119 {
2120 tree fn = TREE_VALUE (candidates);
2121 *targs_out = copy_node (DECL_TI_ARGS (fn));
2122 /* DECL is a re-declaration or partial instantiation of a template
2123 function. */
2124 if (TREE_CODE (fn) == TEMPLATE_DECL)
2125 return fn;
2126 /* It was a specialization of an ordinary member function in a
2127 template class. */
2128 return DECL_TI_TEMPLATE (fn);
2129 }
2130
2131 /* It was a specialization of a template. */
2132 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2133 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2134 {
2135 *targs_out = copy_node (targs);
2136 SET_TMPL_ARGS_LEVEL (*targs_out,
2137 TMPL_ARGS_DEPTH (*targs_out),
2138 TREE_PURPOSE (templates));
2139 }
2140 else
2141 *targs_out = TREE_PURPOSE (templates);
2142 return TREE_VALUE (templates);
2143 }
2144
2145 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2146 but with the default argument values filled in from those in the
2147 TMPL_TYPES. */
2148
2149 static tree
copy_default_args_to_explicit_spec_1(tree spec_types,tree tmpl_types)2150 copy_default_args_to_explicit_spec_1 (tree spec_types,
2151 tree tmpl_types)
2152 {
2153 tree new_spec_types;
2154
2155 if (!spec_types)
2156 return NULL_TREE;
2157
2158 if (spec_types == void_list_node)
2159 return void_list_node;
2160
2161 /* Substitute into the rest of the list. */
2162 new_spec_types =
2163 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2164 TREE_CHAIN (tmpl_types));
2165
2166 /* Add the default argument for this parameter. */
2167 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2168 TREE_VALUE (spec_types),
2169 new_spec_types);
2170 }
2171
2172 /* DECL is an explicit specialization. Replicate default arguments
2173 from the template it specializes. (That way, code like:
2174
2175 template <class T> void f(T = 3);
2176 template <> void f(double);
2177 void g () { f (); }
2178
2179 works, as required.) An alternative approach would be to look up
2180 the correct default arguments at the call-site, but this approach
2181 is consistent with how implicit instantiations are handled. */
2182
2183 static void
copy_default_args_to_explicit_spec(tree decl)2184 copy_default_args_to_explicit_spec (tree decl)
2185 {
2186 tree tmpl;
2187 tree spec_types;
2188 tree tmpl_types;
2189 tree new_spec_types;
2190 tree old_type;
2191 tree new_type;
2192 tree t;
2193 tree object_type = NULL_TREE;
2194 tree in_charge = NULL_TREE;
2195 tree vtt = NULL_TREE;
2196
2197 /* See if there's anything we need to do. */
2198 tmpl = DECL_TI_TEMPLATE (decl);
2199 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2200 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2201 if (TREE_PURPOSE (t))
2202 break;
2203 if (!t)
2204 return;
2205
2206 old_type = TREE_TYPE (decl);
2207 spec_types = TYPE_ARG_TYPES (old_type);
2208
2209 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2210 {
2211 /* Remove the this pointer, but remember the object's type for
2212 CV quals. */
2213 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2214 spec_types = TREE_CHAIN (spec_types);
2215 tmpl_types = TREE_CHAIN (tmpl_types);
2216
2217 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2218 {
2219 /* DECL may contain more parameters than TMPL due to the extra
2220 in-charge parameter in constructors and destructors. */
2221 in_charge = spec_types;
2222 spec_types = TREE_CHAIN (spec_types);
2223 }
2224 if (DECL_HAS_VTT_PARM_P (decl))
2225 {
2226 vtt = spec_types;
2227 spec_types = TREE_CHAIN (spec_types);
2228 }
2229 }
2230
2231 /* Compute the merged default arguments. */
2232 new_spec_types =
2233 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2234
2235 /* Compute the new FUNCTION_TYPE. */
2236 if (object_type)
2237 {
2238 if (vtt)
2239 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2240 TREE_VALUE (vtt),
2241 new_spec_types);
2242
2243 if (in_charge)
2244 /* Put the in-charge parameter back. */
2245 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2246 TREE_VALUE (in_charge),
2247 new_spec_types);
2248
2249 new_type = build_method_type_directly (object_type,
2250 TREE_TYPE (old_type),
2251 new_spec_types);
2252 }
2253 else
2254 new_type = build_function_type (TREE_TYPE (old_type),
2255 new_spec_types);
2256 new_type = cp_build_type_attribute_variant (new_type,
2257 TYPE_ATTRIBUTES (old_type));
2258 new_type = build_exception_variant (new_type,
2259 TYPE_RAISES_EXCEPTIONS (old_type));
2260 TREE_TYPE (decl) = new_type;
2261 }
2262
2263 /* Return the number of template headers we expect to see for a definition
2264 or specialization of CTYPE or one of its non-template members. */
2265
2266 int
num_template_headers_for_class(tree ctype)2267 num_template_headers_for_class (tree ctype)
2268 {
2269 int num_templates = 0;
2270
2271 while (ctype && CLASS_TYPE_P (ctype))
2272 {
2273 /* You're supposed to have one `template <...>' for every
2274 template class, but you don't need one for a full
2275 specialization. For example:
2276
2277 template <class T> struct S{};
2278 template <> struct S<int> { void f(); };
2279 void S<int>::f () {}
2280
2281 is correct; there shouldn't be a `template <>' for the
2282 definition of `S<int>::f'. */
2283 if (!CLASSTYPE_TEMPLATE_INFO (ctype))
2284 /* If CTYPE does not have template information of any
2285 kind, then it is not a template, nor is it nested
2286 within a template. */
2287 break;
2288 if (explicit_class_specialization_p (ctype))
2289 break;
2290 if (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (ctype)))
2291 ++num_templates;
2292
2293 ctype = TYPE_CONTEXT (ctype);
2294 }
2295
2296 return num_templates;
2297 }
2298
2299 /* Do a simple sanity check on the template headers that precede the
2300 variable declaration DECL. */
2301
2302 void
check_template_variable(tree decl)2303 check_template_variable (tree decl)
2304 {
2305 tree ctx = CP_DECL_CONTEXT (decl);
2306 int wanted = num_template_headers_for_class (ctx);
2307 if (!TYPE_P (ctx) || !CLASSTYPE_TEMPLATE_INFO (ctx))
2308 permerror (DECL_SOURCE_LOCATION (decl),
2309 "%qD is not a static data member of a class template", decl);
2310 else if (template_header_count > wanted)
2311 {
2312 bool warned = pedwarn (DECL_SOURCE_LOCATION (decl), 0,
2313 "too many template headers for %D (should be %d)",
2314 decl, wanted);
2315 if (warned && CLASSTYPE_TEMPLATE_SPECIALIZATION (ctx))
2316 inform (DECL_SOURCE_LOCATION (decl),
2317 "members of an explicitly specialized class are defined "
2318 "without a template header");
2319 }
2320 }
2321
2322 /* Check to see if the function just declared, as indicated in
2323 DECLARATOR, and in DECL, is a specialization of a function
2324 template. We may also discover that the declaration is an explicit
2325 instantiation at this point.
2326
2327 Returns DECL, or an equivalent declaration that should be used
2328 instead if all goes well. Issues an error message if something is
2329 amiss. Returns error_mark_node if the error is not easily
2330 recoverable.
2331
2332 FLAGS is a bitmask consisting of the following flags:
2333
2334 2: The function has a definition.
2335 4: The function is a friend.
2336
2337 The TEMPLATE_COUNT is the number of references to qualifying
2338 template classes that appeared in the name of the function. For
2339 example, in
2340
2341 template <class T> struct S { void f(); };
2342 void S<int>::f();
2343
2344 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2345 classes are not counted in the TEMPLATE_COUNT, so that in
2346
2347 template <class T> struct S {};
2348 template <> struct S<int> { void f(); }
2349 template <> void S<int>::f();
2350
2351 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2352 invalid; there should be no template <>.)
2353
2354 If the function is a specialization, it is marked as such via
2355 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2356 is set up correctly, and it is added to the list of specializations
2357 for that template. */
2358
2359 tree
check_explicit_specialization(tree declarator,tree decl,int template_count,int flags)2360 check_explicit_specialization (tree declarator,
2361 tree decl,
2362 int template_count,
2363 int flags)
2364 {
2365 int have_def = flags & 2;
2366 int is_friend = flags & 4;
2367 int specialization = 0;
2368 int explicit_instantiation = 0;
2369 int member_specialization = 0;
2370 tree ctype = DECL_CLASS_CONTEXT (decl);
2371 tree dname = DECL_NAME (decl);
2372 tmpl_spec_kind tsk;
2373
2374 if (is_friend)
2375 {
2376 if (!processing_specialization)
2377 tsk = tsk_none;
2378 else
2379 tsk = tsk_excessive_parms;
2380 }
2381 else
2382 tsk = current_tmpl_spec_kind (template_count);
2383
2384 switch (tsk)
2385 {
2386 case tsk_none:
2387 if (processing_specialization)
2388 {
2389 specialization = 1;
2390 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2391 }
2392 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2393 {
2394 if (is_friend)
2395 /* This could be something like:
2396
2397 template <class T> void f(T);
2398 class S { friend void f<>(int); } */
2399 specialization = 1;
2400 else
2401 {
2402 /* This case handles bogus declarations like template <>
2403 template <class T> void f<int>(); */
2404
2405 error ("template-id %qD in declaration of primary template",
2406 declarator);
2407 return decl;
2408 }
2409 }
2410 break;
2411
2412 case tsk_invalid_member_spec:
2413 /* The error has already been reported in
2414 check_specialization_scope. */
2415 return error_mark_node;
2416
2417 case tsk_invalid_expl_inst:
2418 error ("template parameter list used in explicit instantiation");
2419
2420 /* Fall through. */
2421
2422 case tsk_expl_inst:
2423 if (have_def)
2424 error ("definition provided for explicit instantiation");
2425
2426 explicit_instantiation = 1;
2427 break;
2428
2429 case tsk_excessive_parms:
2430 case tsk_insufficient_parms:
2431 if (tsk == tsk_excessive_parms)
2432 error ("too many template parameter lists in declaration of %qD",
2433 decl);
2434 else if (template_header_count)
2435 error("too few template parameter lists in declaration of %qD", decl);
2436 else
2437 error("explicit specialization of %qD must be introduced by "
2438 "%<template <>%>", decl);
2439
2440 /* Fall through. */
2441 case tsk_expl_spec:
2442 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2443 if (ctype)
2444 member_specialization = 1;
2445 else
2446 specialization = 1;
2447 break;
2448
2449 case tsk_template:
2450 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2451 {
2452 /* This case handles bogus declarations like template <>
2453 template <class T> void f<int>(); */
2454
2455 if (uses_template_parms (declarator))
2456 error ("function template partial specialization %qD "
2457 "is not allowed", declarator);
2458 else
2459 error ("template-id %qD in declaration of primary template",
2460 declarator);
2461 return decl;
2462 }
2463
2464 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2465 /* This is a specialization of a member template, without
2466 specialization the containing class. Something like:
2467
2468 template <class T> struct S {
2469 template <class U> void f (U);
2470 };
2471 template <> template <class U> void S<int>::f(U) {}
2472
2473 That's a specialization -- but of the entire template. */
2474 specialization = 1;
2475 break;
2476
2477 default:
2478 gcc_unreachable ();
2479 }
2480
2481 if (specialization || member_specialization)
2482 {
2483 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2484 for (; t; t = TREE_CHAIN (t))
2485 if (TREE_PURPOSE (t))
2486 {
2487 permerror (input_location,
2488 "default argument specified in explicit specialization");
2489 break;
2490 }
2491 }
2492
2493 if (specialization || member_specialization || explicit_instantiation)
2494 {
2495 tree tmpl = NULL_TREE;
2496 tree targs = NULL_TREE;
2497
2498 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2499 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2500 {
2501 tree fns;
2502
2503 gcc_assert (identifier_p (declarator));
2504 if (ctype)
2505 fns = dname;
2506 else
2507 {
2508 /* If there is no class context, the explicit instantiation
2509 must be at namespace scope. */
2510 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2511
2512 /* Find the namespace binding, using the declaration
2513 context. */
2514 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2515 false, true);
2516 if (fns == error_mark_node || !is_overloaded_fn (fns))
2517 {
2518 error ("%qD is not a template function", dname);
2519 fns = error_mark_node;
2520 }
2521 else
2522 {
2523 tree fn = OVL_CURRENT (fns);
2524 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2525 CP_DECL_CONTEXT (fn)))
2526 error ("%qD is not declared in %qD",
2527 decl, current_namespace);
2528 }
2529 }
2530
2531 declarator = lookup_template_function (fns, NULL_TREE);
2532 }
2533
2534 if (declarator == error_mark_node)
2535 return error_mark_node;
2536
2537 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2538 {
2539 if (!explicit_instantiation)
2540 /* A specialization in class scope. This is invalid,
2541 but the error will already have been flagged by
2542 check_specialization_scope. */
2543 return error_mark_node;
2544 else
2545 {
2546 /* It's not valid to write an explicit instantiation in
2547 class scope, e.g.:
2548
2549 class C { template void f(); }
2550
2551 This case is caught by the parser. However, on
2552 something like:
2553
2554 template class C { void f(); };
2555
2556 (which is invalid) we can get here. The error will be
2557 issued later. */
2558 ;
2559 }
2560
2561 return decl;
2562 }
2563 else if (ctype != NULL_TREE
2564 && (identifier_p (TREE_OPERAND (declarator, 0))))
2565 {
2566 /* Find the list of functions in ctype that have the same
2567 name as the declared function. */
2568 tree name = TREE_OPERAND (declarator, 0);
2569 tree fns = NULL_TREE;
2570 int idx;
2571
2572 if (constructor_name_p (name, ctype))
2573 {
2574 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2575
2576 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2577 : !CLASSTYPE_DESTRUCTORS (ctype))
2578 {
2579 /* From [temp.expl.spec]:
2580
2581 If such an explicit specialization for the member
2582 of a class template names an implicitly-declared
2583 special member function (clause _special_), the
2584 program is ill-formed.
2585
2586 Similar language is found in [temp.explicit]. */
2587 error ("specialization of implicitly-declared special member function");
2588 return error_mark_node;
2589 }
2590
2591 name = is_constructor ? ctor_identifier : dtor_identifier;
2592 }
2593
2594 if (!DECL_CONV_FN_P (decl))
2595 {
2596 idx = lookup_fnfields_1 (ctype, name);
2597 if (idx >= 0)
2598 fns = (*CLASSTYPE_METHOD_VEC (ctype))[idx];
2599 }
2600 else
2601 {
2602 vec<tree, va_gc> *methods;
2603 tree ovl;
2604
2605 /* For a type-conversion operator, we cannot do a
2606 name-based lookup. We might be looking for `operator
2607 int' which will be a specialization of `operator T'.
2608 So, we find *all* the conversion operators, and then
2609 select from them. */
2610 fns = NULL_TREE;
2611
2612 methods = CLASSTYPE_METHOD_VEC (ctype);
2613 if (methods)
2614 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2615 methods->iterate (idx, &ovl);
2616 ++idx)
2617 {
2618 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2619 /* There are no more conversion functions. */
2620 break;
2621
2622 /* Glue all these conversion functions together
2623 with those we already have. */
2624 for (; ovl; ovl = OVL_NEXT (ovl))
2625 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2626 }
2627 }
2628
2629 if (fns == NULL_TREE)
2630 {
2631 error ("no member function %qD declared in %qT", name, ctype);
2632 return error_mark_node;
2633 }
2634 else
2635 TREE_OPERAND (declarator, 0) = fns;
2636 }
2637
2638 /* Figure out what exactly is being specialized at this point.
2639 Note that for an explicit instantiation, even one for a
2640 member function, we cannot tell apriori whether the
2641 instantiation is for a member template, or just a member
2642 function of a template class. Even if a member template is
2643 being instantiated, the member template arguments may be
2644 elided if they can be deduced from the rest of the
2645 declaration. */
2646 tmpl = determine_specialization (declarator, decl,
2647 &targs,
2648 member_specialization,
2649 template_count,
2650 tsk);
2651
2652 if (!tmpl || tmpl == error_mark_node)
2653 /* We couldn't figure out what this declaration was
2654 specializing. */
2655 return error_mark_node;
2656 else
2657 {
2658 tree gen_tmpl = most_general_template (tmpl);
2659
2660 if (explicit_instantiation)
2661 {
2662 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2663 is done by do_decl_instantiation later. */
2664
2665 int arg_depth = TMPL_ARGS_DEPTH (targs);
2666 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2667
2668 if (arg_depth > parm_depth)
2669 {
2670 /* If TMPL is not the most general template (for
2671 example, if TMPL is a friend template that is
2672 injected into namespace scope), then there will
2673 be too many levels of TARGS. Remove some of them
2674 here. */
2675 int i;
2676 tree new_targs;
2677
2678 new_targs = make_tree_vec (parm_depth);
2679 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2680 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2681 = TREE_VEC_ELT (targs, i);
2682 targs = new_targs;
2683 }
2684
2685 return instantiate_template (tmpl, targs, tf_error);
2686 }
2687
2688 /* If we thought that the DECL was a member function, but it
2689 turns out to be specializing a static member function,
2690 make DECL a static member function as well. */
2691 if (DECL_STATIC_FUNCTION_P (tmpl)
2692 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2693 revert_static_member_fn (decl);
2694
2695 /* If this is a specialization of a member template of a
2696 template class, we want to return the TEMPLATE_DECL, not
2697 the specialization of it. */
2698 if (tsk == tsk_template)
2699 {
2700 tree result = DECL_TEMPLATE_RESULT (tmpl);
2701 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2702 DECL_INITIAL (result) = NULL_TREE;
2703 if (have_def)
2704 {
2705 tree parm;
2706 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2707 DECL_SOURCE_LOCATION (result)
2708 = DECL_SOURCE_LOCATION (decl);
2709 /* We want to use the argument list specified in the
2710 definition, not in the original declaration. */
2711 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2712 for (parm = DECL_ARGUMENTS (result); parm;
2713 parm = DECL_CHAIN (parm))
2714 DECL_CONTEXT (parm) = result;
2715 }
2716 return register_specialization (tmpl, gen_tmpl, targs,
2717 is_friend, 0);
2718 }
2719
2720 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2721 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2722
2723 /* Inherit default function arguments from the template
2724 DECL is specializing. */
2725 copy_default_args_to_explicit_spec (decl);
2726
2727 /* This specialization has the same protection as the
2728 template it specializes. */
2729 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2730 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2731
2732 /* 7.1.1-1 [dcl.stc]
2733
2734 A storage-class-specifier shall not be specified in an
2735 explicit specialization...
2736
2737 The parser rejects these, so unless action is taken here,
2738 explicit function specializations will always appear with
2739 global linkage.
2740
2741 The action recommended by the C++ CWG in response to C++
2742 defect report 605 is to make the storage class and linkage
2743 of the explicit specialization match the templated function:
2744
2745 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2746 */
2747 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2748 {
2749 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2750 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2751
2752 /* This specialization has the same linkage and visibility as
2753 the function template it specializes. */
2754 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2755 if (! TREE_PUBLIC (decl))
2756 {
2757 DECL_INTERFACE_KNOWN (decl) = 1;
2758 DECL_NOT_REALLY_EXTERN (decl) = 1;
2759 }
2760 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2761 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2762 {
2763 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2764 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2765 }
2766 }
2767
2768 /* If DECL is a friend declaration, declared using an
2769 unqualified name, the namespace associated with DECL may
2770 have been set incorrectly. For example, in:
2771
2772 template <typename T> void f(T);
2773 namespace N {
2774 struct S { friend void f<int>(int); }
2775 }
2776
2777 we will have set the DECL_CONTEXT for the friend
2778 declaration to N, rather than to the global namespace. */
2779 if (DECL_NAMESPACE_SCOPE_P (decl))
2780 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2781
2782 if (is_friend && !have_def)
2783 /* This is not really a declaration of a specialization.
2784 It's just the name of an instantiation. But, it's not
2785 a request for an instantiation, either. */
2786 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2787
2788 /* Register this specialization so that we can find it
2789 again. */
2790 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2791
2792 /* A 'structor should already have clones. */
2793 gcc_assert (decl == error_mark_node
2794 || !(DECL_CONSTRUCTOR_P (decl)
2795 || DECL_DESTRUCTOR_P (decl))
2796 || DECL_CLONED_FUNCTION_P (DECL_CHAIN (decl)));
2797 }
2798 }
2799
2800 return decl;
2801 }
2802
2803 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2804 parameters. These are represented in the same format used for
2805 DECL_TEMPLATE_PARMS. */
2806
2807 int
comp_template_parms(const_tree parms1,const_tree parms2)2808 comp_template_parms (const_tree parms1, const_tree parms2)
2809 {
2810 const_tree p1;
2811 const_tree p2;
2812
2813 if (parms1 == parms2)
2814 return 1;
2815
2816 for (p1 = parms1, p2 = parms2;
2817 p1 != NULL_TREE && p2 != NULL_TREE;
2818 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2819 {
2820 tree t1 = TREE_VALUE (p1);
2821 tree t2 = TREE_VALUE (p2);
2822 int i;
2823
2824 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2825 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2826
2827 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2828 return 0;
2829
2830 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2831 {
2832 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2833 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2834
2835 /* If either of the template parameters are invalid, assume
2836 they match for the sake of error recovery. */
2837 if (error_operand_p (parm1) || error_operand_p (parm2))
2838 return 1;
2839
2840 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2841 return 0;
2842
2843 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2844 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2845 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2846 continue;
2847 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2848 return 0;
2849 }
2850 }
2851
2852 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2853 /* One set of parameters has more parameters lists than the
2854 other. */
2855 return 0;
2856
2857 return 1;
2858 }
2859
2860 /* Determine whether PARM is a parameter pack. */
2861
2862 bool
template_parameter_pack_p(const_tree parm)2863 template_parameter_pack_p (const_tree parm)
2864 {
2865 /* Determine if we have a non-type template parameter pack. */
2866 if (TREE_CODE (parm) == PARM_DECL)
2867 return (DECL_TEMPLATE_PARM_P (parm)
2868 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2869 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2870 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2871
2872 /* If this is a list of template parameters, we could get a
2873 TYPE_DECL or a TEMPLATE_DECL. */
2874 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2875 parm = TREE_TYPE (parm);
2876
2877 /* Otherwise it must be a type template parameter. */
2878 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2879 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2880 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2881 }
2882
2883 /* Determine if T is a function parameter pack. */
2884
2885 bool
function_parameter_pack_p(const_tree t)2886 function_parameter_pack_p (const_tree t)
2887 {
2888 if (t && TREE_CODE (t) == PARM_DECL)
2889 return DECL_PACK_P (t);
2890 return false;
2891 }
2892
2893 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2894 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2895
2896 tree
get_function_template_decl(const_tree primary_func_tmpl_inst)2897 get_function_template_decl (const_tree primary_func_tmpl_inst)
2898 {
2899 if (! primary_func_tmpl_inst
2900 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2901 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2902 return NULL;
2903
2904 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2905 }
2906
2907 /* Return true iff the function parameter PARAM_DECL was expanded
2908 from the function parameter pack PACK. */
2909
2910 bool
function_parameter_expanded_from_pack_p(tree param_decl,tree pack)2911 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2912 {
2913 if (DECL_ARTIFICIAL (param_decl)
2914 || !function_parameter_pack_p (pack))
2915 return false;
2916
2917 /* The parameter pack and its pack arguments have the same
2918 DECL_PARM_INDEX. */
2919 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2920 }
2921
2922 /* Determine whether ARGS describes a variadic template args list,
2923 i.e., one that is terminated by a template argument pack. */
2924
2925 static bool
template_args_variadic_p(tree args)2926 template_args_variadic_p (tree args)
2927 {
2928 int nargs;
2929 tree last_parm;
2930
2931 if (args == NULL_TREE)
2932 return false;
2933
2934 args = INNERMOST_TEMPLATE_ARGS (args);
2935 nargs = TREE_VEC_LENGTH (args);
2936
2937 if (nargs == 0)
2938 return false;
2939
2940 last_parm = TREE_VEC_ELT (args, nargs - 1);
2941
2942 return ARGUMENT_PACK_P (last_parm);
2943 }
2944
2945 /* Generate a new name for the parameter pack name NAME (an
2946 IDENTIFIER_NODE) that incorporates its */
2947
2948 static tree
make_ith_pack_parameter_name(tree name,int i)2949 make_ith_pack_parameter_name (tree name, int i)
2950 {
2951 /* Munge the name to include the parameter index. */
2952 #define NUMBUF_LEN 128
2953 char numbuf[NUMBUF_LEN];
2954 char* newname;
2955 int newname_len;
2956
2957 if (name == NULL_TREE)
2958 return name;
2959 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2960 newname_len = IDENTIFIER_LENGTH (name)
2961 + strlen (numbuf) + 2;
2962 newname = (char*)alloca (newname_len);
2963 snprintf (newname, newname_len,
2964 "%s#%i", IDENTIFIER_POINTER (name), i);
2965 return get_identifier (newname);
2966 }
2967
2968 /* Return true if T is a primary function, class or alias template
2969 instantiation. */
2970
2971 bool
primary_template_instantiation_p(const_tree t)2972 primary_template_instantiation_p (const_tree t)
2973 {
2974 if (!t)
2975 return false;
2976
2977 if (TREE_CODE (t) == FUNCTION_DECL)
2978 return DECL_LANG_SPECIFIC (t)
2979 && DECL_TEMPLATE_INSTANTIATION (t)
2980 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2981 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2982 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2983 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2984 else if (alias_template_specialization_p (t))
2985 return true;
2986 return false;
2987 }
2988
2989 /* Return true if PARM is a template template parameter. */
2990
2991 bool
template_template_parameter_p(const_tree parm)2992 template_template_parameter_p (const_tree parm)
2993 {
2994 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2995 }
2996
2997 /* Return true iff PARM is a DECL representing a type template
2998 parameter. */
2999
3000 bool
template_type_parameter_p(const_tree parm)3001 template_type_parameter_p (const_tree parm)
3002 {
3003 return (parm
3004 && (TREE_CODE (parm) == TYPE_DECL
3005 || TREE_CODE (parm) == TEMPLATE_DECL)
3006 && DECL_TEMPLATE_PARM_P (parm));
3007 }
3008
3009 /* Return the template parameters of T if T is a
3010 primary template instantiation, NULL otherwise. */
3011
3012 tree
get_primary_template_innermost_parameters(const_tree t)3013 get_primary_template_innermost_parameters (const_tree t)
3014 {
3015 tree parms = NULL, template_info = NULL;
3016
3017 if ((template_info = get_template_info (t))
3018 && primary_template_instantiation_p (t))
3019 parms = INNERMOST_TEMPLATE_PARMS
3020 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
3021
3022 return parms;
3023 }
3024
3025 /* Return the template parameters of the LEVELth level from the full list
3026 of template parameters PARMS. */
3027
3028 tree
get_template_parms_at_level(tree parms,int level)3029 get_template_parms_at_level (tree parms, int level)
3030 {
3031 tree p;
3032 if (!parms
3033 || TREE_CODE (parms) != TREE_LIST
3034 || level > TMPL_PARMS_DEPTH (parms))
3035 return NULL_TREE;
3036
3037 for (p = parms; p; p = TREE_CHAIN (p))
3038 if (TMPL_PARMS_DEPTH (p) == level)
3039 return p;
3040
3041 return NULL_TREE;
3042 }
3043
3044 /* Returns the template arguments of T if T is a template instantiation,
3045 NULL otherwise. */
3046
3047 tree
get_template_innermost_arguments(const_tree t)3048 get_template_innermost_arguments (const_tree t)
3049 {
3050 tree args = NULL, template_info = NULL;
3051
3052 if ((template_info = get_template_info (t))
3053 && TI_ARGS (template_info))
3054 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
3055
3056 return args;
3057 }
3058
3059 /* Return the argument pack elements of T if T is a template argument pack,
3060 NULL otherwise. */
3061
3062 tree
get_template_argument_pack_elems(const_tree t)3063 get_template_argument_pack_elems (const_tree t)
3064 {
3065 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
3066 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
3067 return NULL;
3068
3069 return ARGUMENT_PACK_ARGS (t);
3070 }
3071
3072 /* Structure used to track the progress of find_parameter_packs_r. */
3073 struct find_parameter_pack_data
3074 {
3075 /* TREE_LIST that will contain all of the parameter packs found by
3076 the traversal. */
3077 tree* parameter_packs;
3078
3079 /* Set of AST nodes that have been visited by the traversal. */
3080 struct pointer_set_t *visited;
3081 };
3082
3083 /* Identifies all of the argument packs that occur in a template
3084 argument and appends them to the TREE_LIST inside DATA, which is a
3085 find_parameter_pack_data structure. This is a subroutine of
3086 make_pack_expansion and uses_parameter_packs. */
3087 static tree
find_parameter_packs_r(tree * tp,int * walk_subtrees,void * data)3088 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
3089 {
3090 tree t = *tp;
3091 struct find_parameter_pack_data* ppd =
3092 (struct find_parameter_pack_data*)data;
3093 bool parameter_pack_p = false;
3094
3095 /* Handle type aliases/typedefs. */
3096 if (TYPE_ALIAS_P (t))
3097 {
3098 if (TYPE_TEMPLATE_INFO (t))
3099 cp_walk_tree (&TYPE_TI_ARGS (t),
3100 &find_parameter_packs_r,
3101 ppd, ppd->visited);
3102 *walk_subtrees = 0;
3103 return NULL_TREE;
3104 }
3105
3106 /* Identify whether this is a parameter pack or not. */
3107 switch (TREE_CODE (t))
3108 {
3109 case TEMPLATE_PARM_INDEX:
3110 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3111 parameter_pack_p = true;
3112 break;
3113
3114 case TEMPLATE_TYPE_PARM:
3115 t = TYPE_MAIN_VARIANT (t);
3116 case TEMPLATE_TEMPLATE_PARM:
3117 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3118 parameter_pack_p = true;
3119 break;
3120
3121 case FIELD_DECL:
3122 case PARM_DECL:
3123 if (DECL_PACK_P (t))
3124 {
3125 /* We don't want to walk into the type of a PARM_DECL,
3126 because we don't want to see the type parameter pack. */
3127 *walk_subtrees = 0;
3128 parameter_pack_p = true;
3129 }
3130 break;
3131
3132 /* Look through a lambda capture proxy to the field pack. */
3133 case VAR_DECL:
3134 if (DECL_HAS_VALUE_EXPR_P (t))
3135 {
3136 tree v = DECL_VALUE_EXPR (t);
3137 cp_walk_tree (&v,
3138 &find_parameter_packs_r,
3139 ppd, ppd->visited);
3140 *walk_subtrees = 0;
3141 }
3142 break;
3143
3144 case BASES:
3145 parameter_pack_p = true;
3146 break;
3147 default:
3148 /* Not a parameter pack. */
3149 break;
3150 }
3151
3152 if (parameter_pack_p)
3153 {
3154 /* Add this parameter pack to the list. */
3155 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3156 }
3157
3158 if (TYPE_P (t))
3159 cp_walk_tree (&TYPE_CONTEXT (t),
3160 &find_parameter_packs_r, ppd, ppd->visited);
3161
3162 /* This switch statement will return immediately if we don't find a
3163 parameter pack. */
3164 switch (TREE_CODE (t))
3165 {
3166 case TEMPLATE_PARM_INDEX:
3167 return NULL_TREE;
3168
3169 case BOUND_TEMPLATE_TEMPLATE_PARM:
3170 /* Check the template itself. */
3171 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3172 &find_parameter_packs_r, ppd, ppd->visited);
3173 /* Check the template arguments. */
3174 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3175 ppd->visited);
3176 *walk_subtrees = 0;
3177 return NULL_TREE;
3178
3179 case TEMPLATE_TYPE_PARM:
3180 case TEMPLATE_TEMPLATE_PARM:
3181 return NULL_TREE;
3182
3183 case PARM_DECL:
3184 return NULL_TREE;
3185
3186 case RECORD_TYPE:
3187 if (TYPE_PTRMEMFUNC_P (t))
3188 return NULL_TREE;
3189 /* Fall through. */
3190
3191 case UNION_TYPE:
3192 case ENUMERAL_TYPE:
3193 if (TYPE_TEMPLATE_INFO (t))
3194 cp_walk_tree (&TYPE_TI_ARGS (t),
3195 &find_parameter_packs_r, ppd, ppd->visited);
3196
3197 *walk_subtrees = 0;
3198 return NULL_TREE;
3199
3200 case CONSTRUCTOR:
3201 case TEMPLATE_DECL:
3202 cp_walk_tree (&TREE_TYPE (t),
3203 &find_parameter_packs_r, ppd, ppd->visited);
3204 return NULL_TREE;
3205
3206 case TYPENAME_TYPE:
3207 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3208 ppd, ppd->visited);
3209 *walk_subtrees = 0;
3210 return NULL_TREE;
3211
3212 case TYPE_PACK_EXPANSION:
3213 case EXPR_PACK_EXPANSION:
3214 *walk_subtrees = 0;
3215 return NULL_TREE;
3216
3217 case INTEGER_TYPE:
3218 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3219 ppd, ppd->visited);
3220 *walk_subtrees = 0;
3221 return NULL_TREE;
3222
3223 case IDENTIFIER_NODE:
3224 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3225 ppd->visited);
3226 *walk_subtrees = 0;
3227 return NULL_TREE;
3228
3229 default:
3230 return NULL_TREE;
3231 }
3232
3233 return NULL_TREE;
3234 }
3235
3236 /* Determines if the expression or type T uses any parameter packs. */
3237 bool
uses_parameter_packs(tree t)3238 uses_parameter_packs (tree t)
3239 {
3240 tree parameter_packs = NULL_TREE;
3241 struct find_parameter_pack_data ppd;
3242 ppd.parameter_packs = ¶meter_packs;
3243 ppd.visited = pointer_set_create ();
3244 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3245 pointer_set_destroy (ppd.visited);
3246 return parameter_packs != NULL_TREE;
3247 }
3248
3249 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3250 representation a base-class initializer into a parameter pack
3251 expansion. If all goes well, the resulting node will be an
3252 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3253 respectively. */
3254 tree
make_pack_expansion(tree arg)3255 make_pack_expansion (tree arg)
3256 {
3257 tree result;
3258 tree parameter_packs = NULL_TREE;
3259 bool for_types = false;
3260 struct find_parameter_pack_data ppd;
3261
3262 if (!arg || arg == error_mark_node)
3263 return arg;
3264
3265 if (TREE_CODE (arg) == TREE_LIST)
3266 {
3267 /* The only time we will see a TREE_LIST here is for a base
3268 class initializer. In this case, the TREE_PURPOSE will be a
3269 _TYPE node (representing the base class expansion we're
3270 initializing) and the TREE_VALUE will be a TREE_LIST
3271 containing the initialization arguments.
3272
3273 The resulting expansion looks somewhat different from most
3274 expansions. Rather than returning just one _EXPANSION, we
3275 return a TREE_LIST whose TREE_PURPOSE is a
3276 TYPE_PACK_EXPANSION containing the bases that will be
3277 initialized. The TREE_VALUE will be identical to the
3278 original TREE_VALUE, which is a list of arguments that will
3279 be passed to each base. We do not introduce any new pack
3280 expansion nodes into the TREE_VALUE (although it is possible
3281 that some already exist), because the TREE_PURPOSE and
3282 TREE_VALUE all need to be expanded together with the same
3283 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3284 resulting TREE_PURPOSE will mention the parameter packs in
3285 both the bases and the arguments to the bases. */
3286 tree purpose;
3287 tree value;
3288 tree parameter_packs = NULL_TREE;
3289
3290 /* Determine which parameter packs will be used by the base
3291 class expansion. */
3292 ppd.visited = pointer_set_create ();
3293 ppd.parameter_packs = ¶meter_packs;
3294 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3295 &ppd, ppd.visited);
3296
3297 if (parameter_packs == NULL_TREE)
3298 {
3299 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3300 pointer_set_destroy (ppd.visited);
3301 return error_mark_node;
3302 }
3303
3304 if (TREE_VALUE (arg) != void_type_node)
3305 {
3306 /* Collect the sets of parameter packs used in each of the
3307 initialization arguments. */
3308 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3309 {
3310 /* Determine which parameter packs will be expanded in this
3311 argument. */
3312 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3313 &ppd, ppd.visited);
3314 }
3315 }
3316
3317 pointer_set_destroy (ppd.visited);
3318
3319 /* Create the pack expansion type for the base type. */
3320 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3321 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3322 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3323
3324 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3325 they will rarely be compared to anything. */
3326 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3327
3328 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3329 }
3330
3331 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3332 for_types = true;
3333
3334 /* Build the PACK_EXPANSION_* node. */
3335 result = for_types
3336 ? cxx_make_type (TYPE_PACK_EXPANSION)
3337 : make_node (EXPR_PACK_EXPANSION);
3338 SET_PACK_EXPANSION_PATTERN (result, arg);
3339 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3340 {
3341 /* Propagate type and const-expression information. */
3342 TREE_TYPE (result) = TREE_TYPE (arg);
3343 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3344 }
3345 else
3346 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3347 they will rarely be compared to anything. */
3348 SET_TYPE_STRUCTURAL_EQUALITY (result);
3349
3350 /* Determine which parameter packs will be expanded. */
3351 ppd.parameter_packs = ¶meter_packs;
3352 ppd.visited = pointer_set_create ();
3353 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3354 pointer_set_destroy (ppd.visited);
3355
3356 /* Make sure we found some parameter packs. */
3357 if (parameter_packs == NULL_TREE)
3358 {
3359 if (TYPE_P (arg))
3360 error ("expansion pattern %<%T%> contains no argument packs", arg);
3361 else
3362 error ("expansion pattern %<%E%> contains no argument packs", arg);
3363 return error_mark_node;
3364 }
3365 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3366
3367 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3368
3369 return result;
3370 }
3371
3372 /* Checks T for any "bare" parameter packs, which have not yet been
3373 expanded, and issues an error if any are found. This operation can
3374 only be done on full expressions or types (e.g., an expression
3375 statement, "if" condition, etc.), because we could have expressions like:
3376
3377 foo(f(g(h(args)))...)
3378
3379 where "args" is a parameter pack. check_for_bare_parameter_packs
3380 should not be called for the subexpressions args, h(args),
3381 g(h(args)), or f(g(h(args))), because we would produce erroneous
3382 error messages.
3383
3384 Returns TRUE and emits an error if there were bare parameter packs,
3385 returns FALSE otherwise. */
3386 bool
check_for_bare_parameter_packs(tree t)3387 check_for_bare_parameter_packs (tree t)
3388 {
3389 tree parameter_packs = NULL_TREE;
3390 struct find_parameter_pack_data ppd;
3391
3392 if (!processing_template_decl || !t || t == error_mark_node)
3393 return false;
3394
3395 if (TREE_CODE (t) == TYPE_DECL)
3396 t = TREE_TYPE (t);
3397
3398 ppd.parameter_packs = ¶meter_packs;
3399 ppd.visited = pointer_set_create ();
3400 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3401 pointer_set_destroy (ppd.visited);
3402
3403 if (parameter_packs)
3404 {
3405 error ("parameter packs not expanded with %<...%>:");
3406 while (parameter_packs)
3407 {
3408 tree pack = TREE_VALUE (parameter_packs);
3409 tree name = NULL_TREE;
3410
3411 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3412 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3413 name = TYPE_NAME (pack);
3414 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3415 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3416 else
3417 name = DECL_NAME (pack);
3418
3419 if (name)
3420 inform (input_location, " %qD", name);
3421 else
3422 inform (input_location, " <anonymous>");
3423
3424 parameter_packs = TREE_CHAIN (parameter_packs);
3425 }
3426
3427 return true;
3428 }
3429
3430 return false;
3431 }
3432
3433 /* Expand any parameter packs that occur in the template arguments in
3434 ARGS. */
3435 tree
expand_template_argument_pack(tree args)3436 expand_template_argument_pack (tree args)
3437 {
3438 tree result_args = NULL_TREE;
3439 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3440 int num_result_args = -1;
3441 int non_default_args_count = -1;
3442
3443 /* First, determine if we need to expand anything, and the number of
3444 slots we'll need. */
3445 for (in_arg = 0; in_arg < nargs; ++in_arg)
3446 {
3447 tree arg = TREE_VEC_ELT (args, in_arg);
3448 if (arg == NULL_TREE)
3449 return args;
3450 if (ARGUMENT_PACK_P (arg))
3451 {
3452 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3453 if (num_result_args < 0)
3454 num_result_args = in_arg + num_packed;
3455 else
3456 num_result_args += num_packed;
3457 }
3458 else
3459 {
3460 if (num_result_args >= 0)
3461 num_result_args++;
3462 }
3463 }
3464
3465 /* If no expansion is necessary, we're done. */
3466 if (num_result_args < 0)
3467 return args;
3468
3469 /* Expand arguments. */
3470 result_args = make_tree_vec (num_result_args);
3471 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3472 non_default_args_count =
3473 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3474 for (in_arg = 0; in_arg < nargs; ++in_arg)
3475 {
3476 tree arg = TREE_VEC_ELT (args, in_arg);
3477 if (ARGUMENT_PACK_P (arg))
3478 {
3479 tree packed = ARGUMENT_PACK_ARGS (arg);
3480 int i, num_packed = TREE_VEC_LENGTH (packed);
3481 for (i = 0; i < num_packed; ++i, ++out_arg)
3482 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3483 if (non_default_args_count > 0)
3484 non_default_args_count += num_packed - 1;
3485 }
3486 else
3487 {
3488 TREE_VEC_ELT (result_args, out_arg) = arg;
3489 ++out_arg;
3490 }
3491 }
3492 if (non_default_args_count >= 0)
3493 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3494 return result_args;
3495 }
3496
3497 /* Checks if DECL shadows a template parameter.
3498
3499 [temp.local]: A template-parameter shall not be redeclared within its
3500 scope (including nested scopes).
3501
3502 Emits an error and returns TRUE if the DECL shadows a parameter,
3503 returns FALSE otherwise. */
3504
3505 bool
check_template_shadow(tree decl)3506 check_template_shadow (tree decl)
3507 {
3508 tree olddecl;
3509
3510 /* If we're not in a template, we can't possibly shadow a template
3511 parameter. */
3512 if (!current_template_parms)
3513 return true;
3514
3515 /* Figure out what we're shadowing. */
3516 if (TREE_CODE (decl) == OVERLOAD)
3517 decl = OVL_CURRENT (decl);
3518 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3519
3520 /* If there's no previous binding for this name, we're not shadowing
3521 anything, let alone a template parameter. */
3522 if (!olddecl)
3523 return true;
3524
3525 /* If we're not shadowing a template parameter, we're done. Note
3526 that OLDDECL might be an OVERLOAD (or perhaps even an
3527 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3528 node. */
3529 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3530 return true;
3531
3532 /* We check for decl != olddecl to avoid bogus errors for using a
3533 name inside a class. We check TPFI to avoid duplicate errors for
3534 inline member templates. */
3535 if (decl == olddecl
3536 || (DECL_TEMPLATE_PARM_P (decl)
3537 && TEMPLATE_PARMS_FOR_INLINE (current_template_parms)))
3538 return true;
3539
3540 /* Don't complain about the injected class name, as we've already
3541 complained about the class itself. */
3542 if (DECL_SELF_REFERENCE_P (decl))
3543 return false;
3544
3545 error ("declaration of %q+#D", decl);
3546 error (" shadows template parm %q+#D", olddecl);
3547 return false;
3548 }
3549
3550 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3551 ORIG_LEVEL, DECL, and TYPE. */
3552
3553 static tree
build_template_parm_index(int index,int level,int orig_level,tree decl,tree type)3554 build_template_parm_index (int index,
3555 int level,
3556 int orig_level,
3557 tree decl,
3558 tree type)
3559 {
3560 tree t = make_node (TEMPLATE_PARM_INDEX);
3561 TEMPLATE_PARM_IDX (t) = index;
3562 TEMPLATE_PARM_LEVEL (t) = level;
3563 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3564 TEMPLATE_PARM_DECL (t) = decl;
3565 TREE_TYPE (t) = type;
3566 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3567 TREE_READONLY (t) = TREE_READONLY (decl);
3568
3569 return t;
3570 }
3571
3572 /* Find the canonical type parameter for the given template type
3573 parameter. Returns the canonical type parameter, which may be TYPE
3574 if no such parameter existed. */
3575
3576 static tree
canonical_type_parameter(tree type)3577 canonical_type_parameter (tree type)
3578 {
3579 tree list;
3580 int idx = TEMPLATE_TYPE_IDX (type);
3581 if (!canonical_template_parms)
3582 vec_alloc (canonical_template_parms, idx+1);
3583
3584 while (canonical_template_parms->length () <= (unsigned)idx)
3585 vec_safe_push (canonical_template_parms, NULL_TREE);
3586
3587 list = (*canonical_template_parms)[idx];
3588 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3589 list = TREE_CHAIN (list);
3590
3591 if (list)
3592 return TREE_VALUE (list);
3593 else
3594 {
3595 (*canonical_template_parms)[idx]
3596 = tree_cons (NULL_TREE, type,
3597 (*canonical_template_parms)[idx]);
3598 return type;
3599 }
3600 }
3601
3602 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3603 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3604 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3605 new one is created. */
3606
3607 static tree
reduce_template_parm_level(tree index,tree type,int levels,tree args,tsubst_flags_t complain)3608 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3609 tsubst_flags_t complain)
3610 {
3611 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3612 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3613 != TEMPLATE_PARM_LEVEL (index) - levels)
3614 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3615 {
3616 tree orig_decl = TEMPLATE_PARM_DECL (index);
3617 tree decl, t;
3618
3619 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3620 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3621 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3622 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3623 DECL_ARTIFICIAL (decl) = 1;
3624 SET_DECL_TEMPLATE_PARM_P (decl);
3625
3626 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3627 TEMPLATE_PARM_LEVEL (index) - levels,
3628 TEMPLATE_PARM_ORIG_LEVEL (index),
3629 decl, type);
3630 TEMPLATE_PARM_DESCENDANTS (index) = t;
3631 TEMPLATE_PARM_PARAMETER_PACK (t)
3632 = TEMPLATE_PARM_PARAMETER_PACK (index);
3633
3634 /* Template template parameters need this. */
3635 if (TREE_CODE (decl) == TEMPLATE_DECL)
3636 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3637 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3638 args, complain);
3639 }
3640
3641 return TEMPLATE_PARM_DESCENDANTS (index);
3642 }
3643
3644 /* Process information from new template parameter PARM and append it
3645 to the LIST being built. This new parameter is a non-type
3646 parameter iff IS_NON_TYPE is true. This new parameter is a
3647 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3648 is in PARM_LOC. */
3649
3650 tree
process_template_parm(tree list,location_t parm_loc,tree parm,bool is_non_type,bool is_parameter_pack)3651 process_template_parm (tree list, location_t parm_loc, tree parm,
3652 bool is_non_type, bool is_parameter_pack)
3653 {
3654 tree decl = 0;
3655 tree defval;
3656 int idx = 0;
3657
3658 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3659 defval = TREE_PURPOSE (parm);
3660
3661 if (list)
3662 {
3663 tree p = tree_last (list);
3664
3665 if (p && TREE_VALUE (p) != error_mark_node)
3666 {
3667 p = TREE_VALUE (p);
3668 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3669 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3670 else
3671 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3672 }
3673
3674 ++idx;
3675 }
3676
3677 if (is_non_type)
3678 {
3679 parm = TREE_VALUE (parm);
3680
3681 SET_DECL_TEMPLATE_PARM_P (parm);
3682
3683 if (TREE_TYPE (parm) != error_mark_node)
3684 {
3685 /* [temp.param]
3686
3687 The top-level cv-qualifiers on the template-parameter are
3688 ignored when determining its type. */
3689 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3690 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3691 TREE_TYPE (parm) = error_mark_node;
3692 else if (uses_parameter_packs (TREE_TYPE (parm))
3693 && !is_parameter_pack
3694 /* If we're in a nested template parameter list, the template
3695 template parameter could be a parameter pack. */
3696 && processing_template_parmlist == 1)
3697 {
3698 /* This template parameter is not a parameter pack, but it
3699 should be. Complain about "bare" parameter packs. */
3700 check_for_bare_parameter_packs (TREE_TYPE (parm));
3701
3702 /* Recover by calling this a parameter pack. */
3703 is_parameter_pack = true;
3704 }
3705 }
3706
3707 /* A template parameter is not modifiable. */
3708 TREE_CONSTANT (parm) = 1;
3709 TREE_READONLY (parm) = 1;
3710 decl = build_decl (parm_loc,
3711 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3712 TREE_CONSTANT (decl) = 1;
3713 TREE_READONLY (decl) = 1;
3714 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3715 = build_template_parm_index (idx, processing_template_decl,
3716 processing_template_decl,
3717 decl, TREE_TYPE (parm));
3718
3719 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3720 = is_parameter_pack;
3721 }
3722 else
3723 {
3724 tree t;
3725 parm = TREE_VALUE (TREE_VALUE (parm));
3726
3727 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3728 {
3729 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3730 /* This is for distinguishing between real templates and template
3731 template parameters */
3732 TREE_TYPE (parm) = t;
3733 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3734 decl = parm;
3735 }
3736 else
3737 {
3738 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3739 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3740 decl = build_decl (parm_loc,
3741 TYPE_DECL, parm, t);
3742 }
3743
3744 TYPE_NAME (t) = decl;
3745 TYPE_STUB_DECL (t) = decl;
3746 parm = decl;
3747 TEMPLATE_TYPE_PARM_INDEX (t)
3748 = build_template_parm_index (idx, processing_template_decl,
3749 processing_template_decl,
3750 decl, TREE_TYPE (parm));
3751 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3752 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3753 }
3754 DECL_ARTIFICIAL (decl) = 1;
3755 SET_DECL_TEMPLATE_PARM_P (decl);
3756 pushdecl (decl);
3757 parm = build_tree_list (defval, parm);
3758 return chainon (list, parm);
3759 }
3760
3761 /* The end of a template parameter list has been reached. Process the
3762 tree list into a parameter vector, converting each parameter into a more
3763 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3764 as PARM_DECLs. */
3765
3766 tree
end_template_parm_list(tree parms)3767 end_template_parm_list (tree parms)
3768 {
3769 int nparms;
3770 tree parm, next;
3771 tree saved_parmlist = make_tree_vec (list_length (parms));
3772
3773 current_template_parms
3774 = tree_cons (size_int (processing_template_decl),
3775 saved_parmlist, current_template_parms);
3776
3777 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3778 {
3779 next = TREE_CHAIN (parm);
3780 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3781 TREE_CHAIN (parm) = NULL_TREE;
3782 }
3783
3784 --processing_template_parmlist;
3785
3786 return saved_parmlist;
3787 }
3788
3789 /* end_template_decl is called after a template declaration is seen. */
3790
3791 void
end_template_decl(void)3792 end_template_decl (void)
3793 {
3794 reset_specialization ();
3795
3796 if (! processing_template_decl)
3797 return;
3798
3799 /* This matches the pushlevel in begin_template_parm_list. */
3800 finish_scope ();
3801
3802 --processing_template_decl;
3803 current_template_parms = TREE_CHAIN (current_template_parms);
3804 }
3805
3806 /* Takes a TREE_LIST representing a template parameter and convert it
3807 into an argument suitable to be passed to the type substitution
3808 functions. Note that If the TREE_LIST contains an error_mark
3809 node, the returned argument is error_mark_node. */
3810
3811 static tree
template_parm_to_arg(tree t)3812 template_parm_to_arg (tree t)
3813 {
3814
3815 if (t == NULL_TREE
3816 || TREE_CODE (t) != TREE_LIST)
3817 return t;
3818
3819 if (error_operand_p (TREE_VALUE (t)))
3820 return error_mark_node;
3821
3822 t = TREE_VALUE (t);
3823
3824 if (TREE_CODE (t) == TYPE_DECL
3825 || TREE_CODE (t) == TEMPLATE_DECL)
3826 {
3827 t = TREE_TYPE (t);
3828
3829 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3830 {
3831 /* Turn this argument into a TYPE_ARGUMENT_PACK
3832 with a single element, which expands T. */
3833 tree vec = make_tree_vec (1);
3834 #ifdef ENABLE_CHECKING
3835 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3836 (vec, TREE_VEC_LENGTH (vec));
3837 #endif
3838 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3839
3840 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3841 SET_ARGUMENT_PACK_ARGS (t, vec);
3842 }
3843 }
3844 else
3845 {
3846 t = DECL_INITIAL (t);
3847
3848 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3849 {
3850 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3851 with a single element, which expands T. */
3852 tree vec = make_tree_vec (1);
3853 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3854 #ifdef ENABLE_CHECKING
3855 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3856 (vec, TREE_VEC_LENGTH (vec));
3857 #endif
3858 t = convert_from_reference (t);
3859 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3860
3861 t = make_node (NONTYPE_ARGUMENT_PACK);
3862 SET_ARGUMENT_PACK_ARGS (t, vec);
3863 TREE_TYPE (t) = type;
3864 }
3865 else
3866 t = convert_from_reference (t);
3867 }
3868 return t;
3869 }
3870
3871 /* Given a set of template parameters, return them as a set of template
3872 arguments. The template parameters are represented as a TREE_VEC, in
3873 the form documented in cp-tree.h for template arguments. */
3874
3875 static tree
template_parms_to_args(tree parms)3876 template_parms_to_args (tree parms)
3877 {
3878 tree header;
3879 tree args = NULL_TREE;
3880 int length = TMPL_PARMS_DEPTH (parms);
3881 int l = length;
3882
3883 /* If there is only one level of template parameters, we do not
3884 create a TREE_VEC of TREE_VECs. Instead, we return a single
3885 TREE_VEC containing the arguments. */
3886 if (length > 1)
3887 args = make_tree_vec (length);
3888
3889 for (header = parms; header; header = TREE_CHAIN (header))
3890 {
3891 tree a = copy_node (TREE_VALUE (header));
3892 int i;
3893
3894 TREE_TYPE (a) = NULL_TREE;
3895 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3896 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
3897
3898 #ifdef ENABLE_CHECKING
3899 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
3900 #endif
3901
3902 if (length > 1)
3903 TREE_VEC_ELT (args, --l) = a;
3904 else
3905 args = a;
3906 }
3907
3908 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
3909 /* This can happen for template parms of a template template
3910 parameter, e.g:
3911
3912 template<template<class T, class U> class TT> struct S;
3913
3914 Consider the level of the parms of TT; T and U both have
3915 level 2; TT has no template parm of level 1. So in this case
3916 the first element of full_template_args is NULL_TREE. If we
3917 leave it like this TMPL_ARGS_DEPTH on args returns 1 instead
3918 of 2. This will make tsubst wrongly consider that T and U
3919 have level 1. Instead, let's create a dummy vector as the
3920 first element of full_template_args so that TMPL_ARGS_DEPTH
3921 returns the correct depth for args. */
3922 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
3923 return args;
3924 }
3925
3926 /* Within the declaration of a template, return the currently active
3927 template parameters as an argument TREE_VEC. */
3928
3929 static tree
current_template_args(void)3930 current_template_args (void)
3931 {
3932 return template_parms_to_args (current_template_parms);
3933 }
3934
3935 /* Update the declared TYPE by doing any lookups which were thought to be
3936 dependent, but are not now that we know the SCOPE of the declarator. */
3937
3938 tree
maybe_update_decl_type(tree orig_type,tree scope)3939 maybe_update_decl_type (tree orig_type, tree scope)
3940 {
3941 tree type = orig_type;
3942
3943 if (type == NULL_TREE)
3944 return type;
3945
3946 if (TREE_CODE (orig_type) == TYPE_DECL)
3947 type = TREE_TYPE (type);
3948
3949 if (scope && TYPE_P (scope) && dependent_type_p (scope)
3950 && dependent_type_p (type)
3951 /* Don't bother building up the args in this case. */
3952 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
3953 {
3954 /* tsubst in the args corresponding to the template parameters,
3955 including auto if present. Most things will be unchanged, but
3956 make_typename_type and tsubst_qualified_id will resolve
3957 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3958 tree args = current_template_args ();
3959 tree auto_node = type_uses_auto (type);
3960 tree pushed;
3961 if (auto_node)
3962 {
3963 tree auto_vec = make_tree_vec (1);
3964 TREE_VEC_ELT (auto_vec, 0) = auto_node;
3965 args = add_to_template_args (args, auto_vec);
3966 }
3967 pushed = push_scope (scope);
3968 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
3969 if (pushed)
3970 pop_scope (scope);
3971 }
3972
3973 if (type == error_mark_node)
3974 return orig_type;
3975
3976 if (TREE_CODE (orig_type) == TYPE_DECL)
3977 {
3978 if (same_type_p (type, TREE_TYPE (orig_type)))
3979 type = orig_type;
3980 else
3981 type = TYPE_NAME (type);
3982 }
3983 return type;
3984 }
3985
3986 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3987 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3988 a member template. Used by push_template_decl below. */
3989
3990 static tree
build_template_decl(tree decl,tree parms,bool member_template_p)3991 build_template_decl (tree decl, tree parms, bool member_template_p)
3992 {
3993 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3994 DECL_TEMPLATE_PARMS (tmpl) = parms;
3995 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3996 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
3997 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3998
3999 return tmpl;
4000 }
4001
4002 struct template_parm_data
4003 {
4004 /* The level of the template parameters we are currently
4005 processing. */
4006 int level;
4007
4008 /* The index of the specialization argument we are currently
4009 processing. */
4010 int current_arg;
4011
4012 /* An array whose size is the number of template parameters. The
4013 elements are nonzero if the parameter has been used in any one
4014 of the arguments processed so far. */
4015 int* parms;
4016
4017 /* An array whose size is the number of template arguments. The
4018 elements are nonzero if the argument makes use of template
4019 parameters of this level. */
4020 int* arg_uses_template_parms;
4021 };
4022
4023 /* Subroutine of push_template_decl used to see if each template
4024 parameter in a partial specialization is used in the explicit
4025 argument list. If T is of the LEVEL given in DATA (which is
4026 treated as a template_parm_data*), then DATA->PARMS is marked
4027 appropriately. */
4028
4029 static int
mark_template_parm(tree t,void * data)4030 mark_template_parm (tree t, void* data)
4031 {
4032 int level;
4033 int idx;
4034 struct template_parm_data* tpd = (struct template_parm_data*) data;
4035
4036 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4037 {
4038 level = TEMPLATE_PARM_LEVEL (t);
4039 idx = TEMPLATE_PARM_IDX (t);
4040 }
4041 else
4042 {
4043 level = TEMPLATE_TYPE_LEVEL (t);
4044 idx = TEMPLATE_TYPE_IDX (t);
4045 }
4046
4047 if (level == tpd->level)
4048 {
4049 tpd->parms[idx] = 1;
4050 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4051 }
4052
4053 /* Return zero so that for_each_template_parm will continue the
4054 traversal of the tree; we want to mark *every* template parm. */
4055 return 0;
4056 }
4057
4058 /* Process the partial specialization DECL. */
4059
4060 static tree
process_partial_specialization(tree decl)4061 process_partial_specialization (tree decl)
4062 {
4063 tree type = TREE_TYPE (decl);
4064 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4065 tree specargs = CLASSTYPE_TI_ARGS (type);
4066 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4067 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4068 tree inner_parms;
4069 tree inst;
4070 int nargs = TREE_VEC_LENGTH (inner_args);
4071 int ntparms;
4072 int i;
4073 bool did_error_intro = false;
4074 struct template_parm_data tpd;
4075 struct template_parm_data tpd2;
4076
4077 gcc_assert (current_template_parms);
4078
4079 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4080 ntparms = TREE_VEC_LENGTH (inner_parms);
4081
4082 /* We check that each of the template parameters given in the
4083 partial specialization is used in the argument list to the
4084 specialization. For example:
4085
4086 template <class T> struct S;
4087 template <class T> struct S<T*>;
4088
4089 The second declaration is OK because `T*' uses the template
4090 parameter T, whereas
4091
4092 template <class T> struct S<int>;
4093
4094 is no good. Even trickier is:
4095
4096 template <class T>
4097 struct S1
4098 {
4099 template <class U>
4100 struct S2;
4101 template <class U>
4102 struct S2<T>;
4103 };
4104
4105 The S2<T> declaration is actually invalid; it is a
4106 full-specialization. Of course,
4107
4108 template <class U>
4109 struct S2<T (*)(U)>;
4110
4111 or some such would have been OK. */
4112 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4113 tpd.parms = XALLOCAVEC (int, ntparms);
4114 memset (tpd.parms, 0, sizeof (int) * ntparms);
4115
4116 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4117 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4118 for (i = 0; i < nargs; ++i)
4119 {
4120 tpd.current_arg = i;
4121 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4122 &mark_template_parm,
4123 &tpd,
4124 NULL,
4125 /*include_nondeduced_p=*/false);
4126 }
4127 for (i = 0; i < ntparms; ++i)
4128 if (tpd.parms[i] == 0)
4129 {
4130 /* One of the template parms was not used in a deduced context in the
4131 specialization. */
4132 if (!did_error_intro)
4133 {
4134 error ("template parameters not deducible in "
4135 "partial specialization:");
4136 did_error_intro = true;
4137 }
4138
4139 inform (input_location, " %qD",
4140 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4141 }
4142
4143 if (did_error_intro)
4144 return error_mark_node;
4145
4146 /* [temp.class.spec]
4147
4148 The argument list of the specialization shall not be identical to
4149 the implicit argument list of the primary template. */
4150 if (comp_template_args
4151 (inner_args,
4152 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4153 (maintmpl)))))
4154 error ("partial specialization %qT does not specialize any template arguments", type);
4155
4156 /* A partial specialization that replaces multiple parameters of the
4157 primary template with a pack expansion is less specialized for those
4158 parameters. */
4159 if (nargs < DECL_NTPARMS (maintmpl))
4160 {
4161 error ("partial specialization is not more specialized than the "
4162 "primary template because it replaces multiple parameters "
4163 "with a pack expansion");
4164 inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
4165 return decl;
4166 }
4167
4168 /* [temp.class.spec]
4169
4170 A partially specialized non-type argument expression shall not
4171 involve template parameters of the partial specialization except
4172 when the argument expression is a simple identifier.
4173
4174 The type of a template parameter corresponding to a specialized
4175 non-type argument shall not be dependent on a parameter of the
4176 specialization.
4177
4178 Also, we verify that pack expansions only occur at the
4179 end of the argument list. */
4180 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4181 tpd2.parms = 0;
4182 for (i = 0; i < nargs; ++i)
4183 {
4184 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4185 tree arg = TREE_VEC_ELT (inner_args, i);
4186 tree packed_args = NULL_TREE;
4187 int j, len = 1;
4188
4189 if (ARGUMENT_PACK_P (arg))
4190 {
4191 /* Extract the arguments from the argument pack. We'll be
4192 iterating over these in the following loop. */
4193 packed_args = ARGUMENT_PACK_ARGS (arg);
4194 len = TREE_VEC_LENGTH (packed_args);
4195 }
4196
4197 for (j = 0; j < len; j++)
4198 {
4199 if (packed_args)
4200 /* Get the Jth argument in the parameter pack. */
4201 arg = TREE_VEC_ELT (packed_args, j);
4202
4203 if (PACK_EXPANSION_P (arg))
4204 {
4205 /* Pack expansions must come at the end of the
4206 argument list. */
4207 if ((packed_args && j < len - 1)
4208 || (!packed_args && i < nargs - 1))
4209 {
4210 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4211 error ("parameter pack argument %qE must be at the "
4212 "end of the template argument list", arg);
4213 else
4214 error ("parameter pack argument %qT must be at the "
4215 "end of the template argument list", arg);
4216 }
4217 }
4218
4219 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4220 /* We only care about the pattern. */
4221 arg = PACK_EXPANSION_PATTERN (arg);
4222
4223 if (/* These first two lines are the `non-type' bit. */
4224 !TYPE_P (arg)
4225 && TREE_CODE (arg) != TEMPLATE_DECL
4226 /* This next two lines are the `argument expression is not just a
4227 simple identifier' condition and also the `specialized
4228 non-type argument' bit. */
4229 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX
4230 && !(REFERENCE_REF_P (arg)
4231 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_PARM_INDEX))
4232 {
4233 if ((!packed_args && tpd.arg_uses_template_parms[i])
4234 || (packed_args && uses_template_parms (arg)))
4235 error ("template argument %qE involves template parameter(s)",
4236 arg);
4237 else
4238 {
4239 /* Look at the corresponding template parameter,
4240 marking which template parameters its type depends
4241 upon. */
4242 tree type = TREE_TYPE (parm);
4243
4244 if (!tpd2.parms)
4245 {
4246 /* We haven't yet initialized TPD2. Do so now. */
4247 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4248 /* The number of parameters here is the number in the
4249 main template, which, as checked in the assertion
4250 above, is NARGS. */
4251 tpd2.parms = XALLOCAVEC (int, nargs);
4252 tpd2.level =
4253 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4254 }
4255
4256 /* Mark the template parameters. But this time, we're
4257 looking for the template parameters of the main
4258 template, not in the specialization. */
4259 tpd2.current_arg = i;
4260 tpd2.arg_uses_template_parms[i] = 0;
4261 memset (tpd2.parms, 0, sizeof (int) * nargs);
4262 for_each_template_parm (type,
4263 &mark_template_parm,
4264 &tpd2,
4265 NULL,
4266 /*include_nondeduced_p=*/false);
4267
4268 if (tpd2.arg_uses_template_parms [i])
4269 {
4270 /* The type depended on some template parameters.
4271 If they are fully specialized in the
4272 specialization, that's OK. */
4273 int j;
4274 int count = 0;
4275 for (j = 0; j < nargs; ++j)
4276 if (tpd2.parms[j] != 0
4277 && tpd.arg_uses_template_parms [j])
4278 ++count;
4279 if (count != 0)
4280 error_n (input_location, count,
4281 "type %qT of template argument %qE depends "
4282 "on a template parameter",
4283 "type %qT of template argument %qE depends "
4284 "on template parameters",
4285 type,
4286 arg);
4287 }
4288 }
4289 }
4290 }
4291 }
4292
4293 /* We should only get here once. */
4294 gcc_assert (!COMPLETE_TYPE_P (type));
4295
4296 tree tmpl = build_template_decl (decl, current_template_parms,
4297 DECL_MEMBER_TEMPLATE_P (maintmpl));
4298 TREE_TYPE (tmpl) = type;
4299 DECL_TEMPLATE_RESULT (tmpl) = decl;
4300 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4301 DECL_TEMPLATE_INFO (tmpl) = build_template_info (maintmpl, specargs);
4302 DECL_PRIMARY_TEMPLATE (tmpl) = maintmpl;
4303
4304 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4305 = tree_cons (specargs, tmpl,
4306 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4307 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4308
4309 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4310 inst = TREE_CHAIN (inst))
4311 {
4312 tree inst_type = TREE_VALUE (inst);
4313 if (COMPLETE_TYPE_P (inst_type)
4314 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4315 {
4316 tree spec = most_specialized_class (inst_type, tf_none);
4317 if (spec && TREE_TYPE (spec) == type)
4318 permerror (input_location,
4319 "partial specialization of %qT after instantiation "
4320 "of %qT", type, inst_type);
4321 }
4322 }
4323
4324 return decl;
4325 }
4326
4327 /* PARM is a template parameter of some form; return the corresponding
4328 TEMPLATE_PARM_INDEX. */
4329
4330 static tree
get_template_parm_index(tree parm)4331 get_template_parm_index (tree parm)
4332 {
4333 if (TREE_CODE (parm) == PARM_DECL
4334 || TREE_CODE (parm) == CONST_DECL)
4335 parm = DECL_INITIAL (parm);
4336 else if (TREE_CODE (parm) == TYPE_DECL
4337 || TREE_CODE (parm) == TEMPLATE_DECL)
4338 parm = TREE_TYPE (parm);
4339 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
4340 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
4341 parm = TEMPLATE_TYPE_PARM_INDEX (parm);
4342 gcc_assert (TREE_CODE (parm) == TEMPLATE_PARM_INDEX);
4343 return parm;
4344 }
4345
4346 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4347 parameter packs used by the template parameter PARM. */
4348
4349 static void
fixed_parameter_pack_p_1(tree parm,struct find_parameter_pack_data * ppd)4350 fixed_parameter_pack_p_1 (tree parm, struct find_parameter_pack_data *ppd)
4351 {
4352 /* A type parm can't refer to another parm. */
4353 if (TREE_CODE (parm) == TYPE_DECL)
4354 return;
4355 else if (TREE_CODE (parm) == PARM_DECL)
4356 {
4357 cp_walk_tree (&TREE_TYPE (parm), &find_parameter_packs_r,
4358 ppd, ppd->visited);
4359 return;
4360 }
4361
4362 gcc_assert (TREE_CODE (parm) == TEMPLATE_DECL);
4363
4364 tree vec = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
4365 for (int i = 0; i < TREE_VEC_LENGTH (vec); ++i)
4366 fixed_parameter_pack_p_1 (TREE_VALUE (TREE_VEC_ELT (vec, i)), ppd);
4367 }
4368
4369 /* PARM is a template parameter pack. Return any parameter packs used in
4370 its type or the type of any of its template parameters. If there are
4371 any such packs, it will be instantiated into a fixed template parameter
4372 list by partial instantiation rather than be fully deduced. */
4373
4374 tree
fixed_parameter_pack_p(tree parm)4375 fixed_parameter_pack_p (tree parm)
4376 {
4377 /* This can only be true in a member template. */
4378 if (TEMPLATE_PARM_ORIG_LEVEL (get_template_parm_index (parm)) < 2)
4379 return NULL_TREE;
4380 /* This can only be true for a parameter pack. */
4381 if (!template_parameter_pack_p (parm))
4382 return NULL_TREE;
4383 /* A type parm can't refer to another parm. */
4384 if (TREE_CODE (parm) == TYPE_DECL)
4385 return NULL_TREE;
4386
4387 tree parameter_packs = NULL_TREE;
4388 struct find_parameter_pack_data ppd;
4389 ppd.parameter_packs = ¶meter_packs;
4390 ppd.visited = pointer_set_create ();
4391
4392 fixed_parameter_pack_p_1 (parm, &ppd);
4393
4394 pointer_set_destroy (ppd.visited);
4395 return parameter_packs;
4396 }
4397
4398 /* Check that a template declaration's use of default arguments and
4399 parameter packs is not invalid. Here, PARMS are the template
4400 parameters. IS_PRIMARY is true if DECL is the thing declared by
4401 a primary template. IS_PARTIAL is true if DECL is a partial
4402 specialization.
4403
4404 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4405 declaration (but not a definition); 1 indicates a declaration, 2
4406 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4407 emitted for extraneous default arguments.
4408
4409 Returns TRUE if there were no errors found, FALSE otherwise. */
4410
4411 bool
check_default_tmpl_args(tree decl,tree parms,bool is_primary,bool is_partial,int is_friend_decl)4412 check_default_tmpl_args (tree decl, tree parms, bool is_primary,
4413 bool is_partial, int is_friend_decl)
4414 {
4415 const char *msg;
4416 int last_level_to_check;
4417 tree parm_level;
4418 bool no_errors = true;
4419
4420 /* [temp.param]
4421
4422 A default template-argument shall not be specified in a
4423 function template declaration or a function template definition, nor
4424 in the template-parameter-list of the definition of a member of a
4425 class template. */
4426
4427 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL
4428 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_LOCAL_FUNCTION_P (decl)))
4429 /* You can't have a function template declaration in a local
4430 scope, nor you can you define a member of a class template in a
4431 local scope. */
4432 return true;
4433
4434 if ((TREE_CODE (decl) == TYPE_DECL
4435 && TREE_TYPE (decl)
4436 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4437 || (TREE_CODE (decl) == FUNCTION_DECL
4438 && LAMBDA_FUNCTION_P (decl)))
4439 /* A lambda doesn't have an explicit declaration; don't complain
4440 about the parms of the enclosing class. */
4441 return true;
4442
4443 if (current_class_type
4444 && !TYPE_BEING_DEFINED (current_class_type)
4445 && DECL_LANG_SPECIFIC (decl)
4446 && DECL_DECLARES_FUNCTION_P (decl)
4447 /* If this is either a friend defined in the scope of the class
4448 or a member function. */
4449 && (DECL_FUNCTION_MEMBER_P (decl)
4450 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4451 : DECL_FRIEND_CONTEXT (decl)
4452 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4453 : false)
4454 /* And, if it was a member function, it really was defined in
4455 the scope of the class. */
4456 && (!DECL_FUNCTION_MEMBER_P (decl)
4457 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4458 /* We already checked these parameters when the template was
4459 declared, so there's no need to do it again now. This function
4460 was defined in class scope, but we're processing its body now
4461 that the class is complete. */
4462 return true;
4463
4464 /* Core issue 226 (C++0x only): the following only applies to class
4465 templates. */
4466 if (is_primary
4467 && ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL))
4468 {
4469 /* [temp.param]
4470
4471 If a template-parameter has a default template-argument, all
4472 subsequent template-parameters shall have a default
4473 template-argument supplied. */
4474 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4475 {
4476 tree inner_parms = TREE_VALUE (parm_level);
4477 int ntparms = TREE_VEC_LENGTH (inner_parms);
4478 int seen_def_arg_p = 0;
4479 int i;
4480
4481 for (i = 0; i < ntparms; ++i)
4482 {
4483 tree parm = TREE_VEC_ELT (inner_parms, i);
4484
4485 if (parm == error_mark_node)
4486 continue;
4487
4488 if (TREE_PURPOSE (parm))
4489 seen_def_arg_p = 1;
4490 else if (seen_def_arg_p
4491 && !template_parameter_pack_p (TREE_VALUE (parm)))
4492 {
4493 error ("no default argument for %qD", TREE_VALUE (parm));
4494 /* For better subsequent error-recovery, we indicate that
4495 there should have been a default argument. */
4496 TREE_PURPOSE (parm) = error_mark_node;
4497 no_errors = false;
4498 }
4499 else if (!is_partial
4500 && !is_friend_decl
4501 /* Don't complain about an enclosing partial
4502 specialization. */
4503 && parm_level == parms
4504 && TREE_CODE (decl) == TYPE_DECL
4505 && i < ntparms - 1
4506 && template_parameter_pack_p (TREE_VALUE (parm))
4507 /* A fixed parameter pack will be partially
4508 instantiated into a fixed length list. */
4509 && !fixed_parameter_pack_p (TREE_VALUE (parm)))
4510 {
4511 /* A primary class template can only have one
4512 parameter pack, at the end of the template
4513 parameter list. */
4514
4515 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4516 error ("parameter pack %qE must be at the end of the"
4517 " template parameter list", TREE_VALUE (parm));
4518 else
4519 error ("parameter pack %qT must be at the end of the"
4520 " template parameter list",
4521 TREE_TYPE (TREE_VALUE (parm)));
4522
4523 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4524 = error_mark_node;
4525 no_errors = false;
4526 }
4527 }
4528 }
4529 }
4530
4531 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4532 || is_partial
4533 || !is_primary
4534 || is_friend_decl)
4535 /* For an ordinary class template, default template arguments are
4536 allowed at the innermost level, e.g.:
4537 template <class T = int>
4538 struct S {};
4539 but, in a partial specialization, they're not allowed even
4540 there, as we have in [temp.class.spec]:
4541
4542 The template parameter list of a specialization shall not
4543 contain default template argument values.
4544
4545 So, for a partial specialization, or for a function template
4546 (in C++98/C++03), we look at all of them. */
4547 ;
4548 else
4549 /* But, for a primary class template that is not a partial
4550 specialization we look at all template parameters except the
4551 innermost ones. */
4552 parms = TREE_CHAIN (parms);
4553
4554 /* Figure out what error message to issue. */
4555 if (is_friend_decl == 2)
4556 msg = G_("default template arguments may not be used in function template "
4557 "friend re-declaration");
4558 else if (is_friend_decl)
4559 msg = G_("default template arguments may not be used in function template "
4560 "friend declarations");
4561 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4562 msg = G_("default template arguments may not be used in function templates "
4563 "without -std=c++11 or -std=gnu++11");
4564 else if (is_partial)
4565 msg = G_("default template arguments may not be used in "
4566 "partial specializations");
4567 else
4568 msg = G_("default argument for template parameter for class enclosing %qD");
4569
4570 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4571 /* If we're inside a class definition, there's no need to
4572 examine the parameters to the class itself. On the one
4573 hand, they will be checked when the class is defined, and,
4574 on the other, default arguments are valid in things like:
4575 template <class T = double>
4576 struct S { template <class U> void f(U); };
4577 Here the default argument for `S' has no bearing on the
4578 declaration of `f'. */
4579 last_level_to_check = template_class_depth (current_class_type) + 1;
4580 else
4581 /* Check everything. */
4582 last_level_to_check = 0;
4583
4584 for (parm_level = parms;
4585 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4586 parm_level = TREE_CHAIN (parm_level))
4587 {
4588 tree inner_parms = TREE_VALUE (parm_level);
4589 int i;
4590 int ntparms;
4591
4592 ntparms = TREE_VEC_LENGTH (inner_parms);
4593 for (i = 0; i < ntparms; ++i)
4594 {
4595 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4596 continue;
4597
4598 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4599 {
4600 if (msg)
4601 {
4602 no_errors = false;
4603 if (is_friend_decl == 2)
4604 return no_errors;
4605
4606 error (msg, decl);
4607 msg = 0;
4608 }
4609
4610 /* Clear out the default argument so that we are not
4611 confused later. */
4612 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4613 }
4614 }
4615
4616 /* At this point, if we're still interested in issuing messages,
4617 they must apply to classes surrounding the object declared. */
4618 if (msg)
4619 msg = G_("default argument for template parameter for class "
4620 "enclosing %qD");
4621 }
4622
4623 return no_errors;
4624 }
4625
4626 /* Worker for push_template_decl_real, called via
4627 for_each_template_parm. DATA is really an int, indicating the
4628 level of the parameters we are interested in. If T is a template
4629 parameter of that level, return nonzero. */
4630
4631 static int
template_parm_this_level_p(tree t,void * data)4632 template_parm_this_level_p (tree t, void* data)
4633 {
4634 int this_level = *(int *)data;
4635 int level;
4636
4637 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4638 level = TEMPLATE_PARM_LEVEL (t);
4639 else
4640 level = TEMPLATE_TYPE_LEVEL (t);
4641 return level == this_level;
4642 }
4643
4644 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4645 parameters given by current_template_args, or reuses a
4646 previously existing one, if appropriate. Returns the DECL, or an
4647 equivalent one, if it is replaced via a call to duplicate_decls.
4648
4649 If IS_FRIEND is true, DECL is a friend declaration. */
4650
4651 tree
push_template_decl_real(tree decl,bool is_friend)4652 push_template_decl_real (tree decl, bool is_friend)
4653 {
4654 tree tmpl;
4655 tree args;
4656 tree info;
4657 tree ctx;
4658 bool is_primary;
4659 bool is_partial;
4660 int new_template_p = 0;
4661 /* True if the template is a member template, in the sense of
4662 [temp.mem]. */
4663 bool member_template_p = false;
4664
4665 if (decl == error_mark_node || !current_template_parms)
4666 return error_mark_node;
4667
4668 /* See if this is a partial specialization. */
4669 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4670 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4671 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4672
4673 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4674 is_friend = true;
4675
4676 if (is_friend)
4677 /* For a friend, we want the context of the friend function, not
4678 the type of which it is a friend. */
4679 ctx = CP_DECL_CONTEXT (decl);
4680 else if (CP_DECL_CONTEXT (decl)
4681 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4682 /* In the case of a virtual function, we want the class in which
4683 it is defined. */
4684 ctx = CP_DECL_CONTEXT (decl);
4685 else
4686 /* Otherwise, if we're currently defining some class, the DECL
4687 is assumed to be a member of the class. */
4688 ctx = current_scope ();
4689
4690 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4691 ctx = NULL_TREE;
4692
4693 if (!DECL_CONTEXT (decl))
4694 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4695
4696 /* See if this is a primary template. */
4697 if (is_friend && ctx
4698 && uses_template_parms_level (ctx, processing_template_decl))
4699 /* A friend template that specifies a class context, i.e.
4700 template <typename T> friend void A<T>::f();
4701 is not primary. */
4702 is_primary = false;
4703 else if (TREE_CODE (decl) == TYPE_DECL
4704 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4705 is_primary = false;
4706 else
4707 is_primary = template_parm_scope_p ();
4708
4709 if (is_primary)
4710 {
4711 if (DECL_CLASS_SCOPE_P (decl))
4712 member_template_p = true;
4713 if (TREE_CODE (decl) == TYPE_DECL
4714 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4715 {
4716 error ("template class without a name");
4717 return error_mark_node;
4718 }
4719 else if (TREE_CODE (decl) == FUNCTION_DECL)
4720 {
4721 if (DECL_DESTRUCTOR_P (decl))
4722 {
4723 /* [temp.mem]
4724
4725 A destructor shall not be a member template. */
4726 error ("destructor %qD declared as member template", decl);
4727 return error_mark_node;
4728 }
4729 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4730 && (!prototype_p (TREE_TYPE (decl))
4731 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4732 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4733 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4734 == void_list_node)))
4735 {
4736 /* [basic.stc.dynamic.allocation]
4737
4738 An allocation function can be a function
4739 template. ... Template allocation functions shall
4740 have two or more parameters. */
4741 error ("invalid template declaration of %qD", decl);
4742 return error_mark_node;
4743 }
4744 }
4745 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4746 && CLASS_TYPE_P (TREE_TYPE (decl)))
4747 /* OK */;
4748 else if (TREE_CODE (decl) == TYPE_DECL
4749 && TYPE_DECL_ALIAS_P (decl))
4750 /* alias-declaration */
4751 gcc_assert (!DECL_ARTIFICIAL (decl));
4752 else
4753 {
4754 error ("template declaration of %q#D", decl);
4755 return error_mark_node;
4756 }
4757 }
4758
4759 /* Check to see that the rules regarding the use of default
4760 arguments are not being violated. */
4761 check_default_tmpl_args (decl, current_template_parms,
4762 is_primary, is_partial, /*is_friend_decl=*/0);
4763
4764 /* Ensure that there are no parameter packs in the type of this
4765 declaration that have not been expanded. */
4766 if (TREE_CODE (decl) == FUNCTION_DECL)
4767 {
4768 /* Check each of the arguments individually to see if there are
4769 any bare parameter packs. */
4770 tree type = TREE_TYPE (decl);
4771 tree arg = DECL_ARGUMENTS (decl);
4772 tree argtype = TYPE_ARG_TYPES (type);
4773
4774 while (arg && argtype)
4775 {
4776 if (!DECL_PACK_P (arg)
4777 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4778 {
4779 /* This is a PARM_DECL that contains unexpanded parameter
4780 packs. We have already complained about this in the
4781 check_for_bare_parameter_packs call, so just replace
4782 these types with ERROR_MARK_NODE. */
4783 TREE_TYPE (arg) = error_mark_node;
4784 TREE_VALUE (argtype) = error_mark_node;
4785 }
4786
4787 arg = DECL_CHAIN (arg);
4788 argtype = TREE_CHAIN (argtype);
4789 }
4790
4791 /* Check for bare parameter packs in the return type and the
4792 exception specifiers. */
4793 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4794 /* Errors were already issued, set return type to int
4795 as the frontend doesn't expect error_mark_node as
4796 the return type. */
4797 TREE_TYPE (type) = integer_type_node;
4798 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4799 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4800 }
4801 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4802 && TYPE_DECL_ALIAS_P (decl))
4803 ? DECL_ORIGINAL_TYPE (decl)
4804 : TREE_TYPE (decl)))
4805 {
4806 TREE_TYPE (decl) = error_mark_node;
4807 return error_mark_node;
4808 }
4809
4810 if (is_partial)
4811 return process_partial_specialization (decl);
4812
4813 args = current_template_args ();
4814
4815 if (!ctx
4816 || TREE_CODE (ctx) == FUNCTION_DECL
4817 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4818 || (TREE_CODE (decl) == TYPE_DECL
4819 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4820 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4821 {
4822 if (DECL_LANG_SPECIFIC (decl)
4823 && DECL_TEMPLATE_INFO (decl)
4824 && DECL_TI_TEMPLATE (decl))
4825 tmpl = DECL_TI_TEMPLATE (decl);
4826 /* If DECL is a TYPE_DECL for a class-template, then there won't
4827 be DECL_LANG_SPECIFIC. The information equivalent to
4828 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4829 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4830 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4831 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4832 {
4833 /* Since a template declaration already existed for this
4834 class-type, we must be redeclaring it here. Make sure
4835 that the redeclaration is valid. */
4836 redeclare_class_template (TREE_TYPE (decl),
4837 current_template_parms);
4838 /* We don't need to create a new TEMPLATE_DECL; just use the
4839 one we already had. */
4840 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4841 }
4842 else
4843 {
4844 tmpl = build_template_decl (decl, current_template_parms,
4845 member_template_p);
4846 new_template_p = 1;
4847
4848 if (DECL_LANG_SPECIFIC (decl)
4849 && DECL_TEMPLATE_SPECIALIZATION (decl))
4850 {
4851 /* A specialization of a member template of a template
4852 class. */
4853 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4854 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4855 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4856 }
4857 }
4858 }
4859 else
4860 {
4861 tree a, t, current, parms;
4862 int i;
4863 tree tinfo = get_template_info (decl);
4864
4865 if (!tinfo)
4866 {
4867 error ("template definition of non-template %q#D", decl);
4868 return error_mark_node;
4869 }
4870
4871 tmpl = TI_TEMPLATE (tinfo);
4872
4873 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4874 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4875 && DECL_TEMPLATE_SPECIALIZATION (decl)
4876 && DECL_MEMBER_TEMPLATE_P (tmpl))
4877 {
4878 tree new_tmpl;
4879
4880 /* The declaration is a specialization of a member
4881 template, declared outside the class. Therefore, the
4882 innermost template arguments will be NULL, so we
4883 replace them with the arguments determined by the
4884 earlier call to check_explicit_specialization. */
4885 args = DECL_TI_ARGS (decl);
4886
4887 new_tmpl
4888 = build_template_decl (decl, current_template_parms,
4889 member_template_p);
4890 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4891 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4892 DECL_TI_TEMPLATE (decl) = new_tmpl;
4893 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4894 DECL_TEMPLATE_INFO (new_tmpl)
4895 = build_template_info (tmpl, args);
4896
4897 register_specialization (new_tmpl,
4898 most_general_template (tmpl),
4899 args,
4900 is_friend, 0);
4901 return decl;
4902 }
4903
4904 /* Make sure the template headers we got make sense. */
4905
4906 parms = DECL_TEMPLATE_PARMS (tmpl);
4907 i = TMPL_PARMS_DEPTH (parms);
4908 if (TMPL_ARGS_DEPTH (args) != i)
4909 {
4910 error ("expected %d levels of template parms for %q#D, got %d",
4911 i, decl, TMPL_ARGS_DEPTH (args));
4912 DECL_INTERFACE_KNOWN (decl) = 1;
4913 return error_mark_node;
4914 }
4915 else
4916 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4917 {
4918 a = TMPL_ARGS_LEVEL (args, i);
4919 t = INNERMOST_TEMPLATE_PARMS (parms);
4920
4921 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4922 {
4923 if (current == decl)
4924 error ("got %d template parameters for %q#D",
4925 TREE_VEC_LENGTH (a), decl);
4926 else
4927 error ("got %d template parameters for %q#T",
4928 TREE_VEC_LENGTH (a), current);
4929 error (" but %d required", TREE_VEC_LENGTH (t));
4930 /* Avoid crash in import_export_decl. */
4931 DECL_INTERFACE_KNOWN (decl) = 1;
4932 return error_mark_node;
4933 }
4934
4935 if (current == decl)
4936 current = ctx;
4937 else if (current == NULL_TREE)
4938 /* Can happen in erroneous input. */
4939 break;
4940 else
4941 current = get_containing_scope (current);
4942 }
4943
4944 /* Check that the parms are used in the appropriate qualifying scopes
4945 in the declarator. */
4946 if (!comp_template_args
4947 (TI_ARGS (tinfo),
4948 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4949 {
4950 error ("\
4951 template arguments to %qD do not match original template %qD",
4952 decl, DECL_TEMPLATE_RESULT (tmpl));
4953 if (!uses_template_parms (TI_ARGS (tinfo)))
4954 inform (input_location, "use template<> for an explicit specialization");
4955 /* Avoid crash in import_export_decl. */
4956 DECL_INTERFACE_KNOWN (decl) = 1;
4957 return error_mark_node;
4958 }
4959 }
4960
4961 DECL_TEMPLATE_RESULT (tmpl) = decl;
4962 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4963
4964 /* Push template declarations for global functions and types. Note
4965 that we do not try to push a global template friend declared in a
4966 template class; such a thing may well depend on the template
4967 parameters of the class. */
4968 if (new_template_p && !ctx
4969 && !(is_friend && template_class_depth (current_class_type) > 0))
4970 {
4971 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4972 if (tmpl == error_mark_node)
4973 return error_mark_node;
4974
4975 /* Hide template friend classes that haven't been declared yet. */
4976 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4977 {
4978 DECL_ANTICIPATED (tmpl) = 1;
4979 DECL_FRIEND_P (tmpl) = 1;
4980 }
4981 }
4982
4983 if (is_primary)
4984 {
4985 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4986 int i;
4987
4988 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4989 if (DECL_CONV_FN_P (tmpl))
4990 {
4991 int depth = TMPL_PARMS_DEPTH (parms);
4992
4993 /* It is a conversion operator. See if the type converted to
4994 depends on innermost template operands. */
4995
4996 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4997 depth))
4998 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4999 }
5000
5001 /* Give template template parms a DECL_CONTEXT of the template
5002 for which they are a parameter. */
5003 parms = INNERMOST_TEMPLATE_PARMS (parms);
5004 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5005 {
5006 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5007 if (TREE_CODE (parm) == TEMPLATE_DECL)
5008 DECL_CONTEXT (parm) = tmpl;
5009 }
5010 }
5011
5012 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5013 back to its most general template. If TMPL is a specialization,
5014 ARGS may only have the innermost set of arguments. Add the missing
5015 argument levels if necessary. */
5016 if (DECL_TEMPLATE_INFO (tmpl))
5017 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5018
5019 info = build_template_info (tmpl, args);
5020
5021 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5022 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5023 else
5024 {
5025 if (is_primary && !DECL_LANG_SPECIFIC (decl))
5026 retrofit_lang_decl (decl);
5027 if (DECL_LANG_SPECIFIC (decl))
5028 DECL_TEMPLATE_INFO (decl) = info;
5029 }
5030
5031 return DECL_TEMPLATE_RESULT (tmpl);
5032 }
5033
5034 tree
push_template_decl(tree decl)5035 push_template_decl (tree decl)
5036 {
5037 return push_template_decl_real (decl, false);
5038 }
5039
5040 /* FN is an inheriting constructor that inherits from the constructor
5041 template INHERITED; turn FN into a constructor template with a matching
5042 template header. */
5043
5044 tree
add_inherited_template_parms(tree fn,tree inherited)5045 add_inherited_template_parms (tree fn, tree inherited)
5046 {
5047 tree inner_parms
5048 = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (inherited));
5049 inner_parms = copy_node (inner_parms);
5050 tree parms
5051 = tree_cons (size_int (processing_template_decl + 1),
5052 inner_parms, current_template_parms);
5053 tree tmpl = build_template_decl (fn, parms, /*member*/true);
5054 tree args = template_parms_to_args (parms);
5055 DECL_TEMPLATE_INFO (fn) = build_template_info (tmpl, args);
5056 TREE_TYPE (tmpl) = TREE_TYPE (fn);
5057 DECL_TEMPLATE_RESULT (tmpl) = fn;
5058 DECL_ARTIFICIAL (tmpl) = true;
5059 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5060 return tmpl;
5061 }
5062
5063 /* Called when a class template TYPE is redeclared with the indicated
5064 template PARMS, e.g.:
5065
5066 template <class T> struct S;
5067 template <class T> struct S {}; */
5068
5069 bool
redeclare_class_template(tree type,tree parms)5070 redeclare_class_template (tree type, tree parms)
5071 {
5072 tree tmpl;
5073 tree tmpl_parms;
5074 int i;
5075
5076 if (!TYPE_TEMPLATE_INFO (type))
5077 {
5078 error ("%qT is not a template type", type);
5079 return false;
5080 }
5081
5082 tmpl = TYPE_TI_TEMPLATE (type);
5083 if (!PRIMARY_TEMPLATE_P (tmpl))
5084 /* The type is nested in some template class. Nothing to worry
5085 about here; there are no new template parameters for the nested
5086 type. */
5087 return true;
5088
5089 if (!parms)
5090 {
5091 error ("template specifiers not specified in declaration of %qD",
5092 tmpl);
5093 return false;
5094 }
5095
5096 parms = INNERMOST_TEMPLATE_PARMS (parms);
5097 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5098
5099 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5100 {
5101 error_n (input_location, TREE_VEC_LENGTH (parms),
5102 "redeclared with %d template parameter",
5103 "redeclared with %d template parameters",
5104 TREE_VEC_LENGTH (parms));
5105 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5106 "previous declaration %q+D used %d template parameter",
5107 "previous declaration %q+D used %d template parameters",
5108 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5109 return false;
5110 }
5111
5112 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5113 {
5114 tree tmpl_parm;
5115 tree parm;
5116 tree tmpl_default;
5117 tree parm_default;
5118
5119 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5120 || TREE_VEC_ELT (parms, i) == error_mark_node)
5121 continue;
5122
5123 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5124 if (error_operand_p (tmpl_parm))
5125 return false;
5126
5127 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5128 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5129 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5130
5131 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5132 TEMPLATE_DECL. */
5133 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5134 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5135 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5136 || (TREE_CODE (tmpl_parm) != PARM_DECL
5137 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5138 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5139 || (TREE_CODE (tmpl_parm) == PARM_DECL
5140 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5141 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5142 {
5143 error ("template parameter %q+#D", tmpl_parm);
5144 error ("redeclared here as %q#D", parm);
5145 return false;
5146 }
5147
5148 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5149 {
5150 /* We have in [temp.param]:
5151
5152 A template-parameter may not be given default arguments
5153 by two different declarations in the same scope. */
5154 error_at (input_location, "redefinition of default argument for %q#D", parm);
5155 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5156 "original definition appeared here");
5157 return false;
5158 }
5159
5160 if (parm_default != NULL_TREE)
5161 /* Update the previous template parameters (which are the ones
5162 that will really count) with the new default value. */
5163 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5164 else if (tmpl_default != NULL_TREE)
5165 /* Update the new parameters, too; they'll be used as the
5166 parameters for any members. */
5167 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5168 }
5169
5170 return true;
5171 }
5172
5173 /* Simplify EXPR if it is a non-dependent expression. Returns the
5174 (possibly simplified) expression. */
5175
5176 tree
fold_non_dependent_expr_sfinae(tree expr,tsubst_flags_t complain)5177 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5178 {
5179 if (expr == NULL_TREE)
5180 return NULL_TREE;
5181
5182 /* If we're in a template, but EXPR isn't value dependent, simplify
5183 it. We're supposed to treat:
5184
5185 template <typename T> void f(T[1 + 1]);
5186 template <typename T> void f(T[2]);
5187
5188 as two declarations of the same function, for example. */
5189 if (processing_template_decl
5190 && !instantiation_dependent_expression_p (expr)
5191 && potential_constant_expression (expr))
5192 {
5193 HOST_WIDE_INT saved_processing_template_decl;
5194
5195 saved_processing_template_decl = processing_template_decl;
5196 processing_template_decl = 0;
5197 expr = tsubst_copy_and_build (expr,
5198 /*args=*/NULL_TREE,
5199 complain,
5200 /*in_decl=*/NULL_TREE,
5201 /*function_p=*/false,
5202 /*integral_constant_expression_p=*/true);
5203 processing_template_decl = saved_processing_template_decl;
5204 }
5205 return expr;
5206 }
5207
5208 tree
fold_non_dependent_expr(tree expr)5209 fold_non_dependent_expr (tree expr)
5210 {
5211 return fold_non_dependent_expr_sfinae (expr, tf_error);
5212 }
5213
5214 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5215 template declaration, or a TYPE_DECL for an alias declaration. */
5216
5217 bool
alias_type_or_template_p(tree t)5218 alias_type_or_template_p (tree t)
5219 {
5220 if (t == NULL_TREE)
5221 return false;
5222 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5223 || (TYPE_P (t)
5224 && TYPE_NAME (t)
5225 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5226 || DECL_ALIAS_TEMPLATE_P (t));
5227 }
5228
5229 /* Return TRUE iff is a specialization of an alias template. */
5230
5231 bool
alias_template_specialization_p(const_tree t)5232 alias_template_specialization_p (const_tree t)
5233 {
5234 if (t == NULL_TREE)
5235 return false;
5236
5237 return (TYPE_P (t)
5238 && TYPE_TEMPLATE_INFO (t)
5239 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
5240 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5241 }
5242
5243 /* Return the number of innermost template parameters in TMPL. */
5244
5245 static int
num_innermost_template_parms(tree tmpl)5246 num_innermost_template_parms (tree tmpl)
5247 {
5248 tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl));
5249 return TREE_VEC_LENGTH (parms);
5250 }
5251
5252 /* Return either TMPL or another template that it is equivalent to under DR
5253 1286: An alias that just changes the name of a template is equivalent to
5254 the other template. */
5255
5256 static tree
get_underlying_template(tree tmpl)5257 get_underlying_template (tree tmpl)
5258 {
5259 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
5260 while (DECL_ALIAS_TEMPLATE_P (tmpl))
5261 {
5262 tree result = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
5263 if (TYPE_TEMPLATE_INFO (result))
5264 {
5265 tree sub = TYPE_TI_TEMPLATE (result);
5266 if (PRIMARY_TEMPLATE_P (sub)
5267 && (num_innermost_template_parms (tmpl)
5268 == num_innermost_template_parms (sub)))
5269 {
5270 tree alias_args = INNERMOST_TEMPLATE_ARGS
5271 (template_parms_to_args (DECL_TEMPLATE_PARMS (tmpl)));
5272 if (!comp_template_args (TYPE_TI_ARGS (result), alias_args))
5273 break;
5274 /* The alias type is equivalent to the pattern of the
5275 underlying template, so strip the alias. */
5276 tmpl = sub;
5277 continue;
5278 }
5279 }
5280 break;
5281 }
5282 return tmpl;
5283 }
5284
5285 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5286 must be a function or a pointer-to-function type, as specified
5287 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5288 and check that the resulting function has external linkage. */
5289
5290 static tree
convert_nontype_argument_function(tree type,tree expr)5291 convert_nontype_argument_function (tree type, tree expr)
5292 {
5293 tree fns = expr;
5294 tree fn, fn_no_ptr;
5295 linkage_kind linkage;
5296
5297 fn = instantiate_type (type, fns, tf_none);
5298 if (fn == error_mark_node)
5299 return error_mark_node;
5300
5301 fn_no_ptr = fn;
5302 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5303 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5304 if (BASELINK_P (fn_no_ptr))
5305 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5306
5307 /* [temp.arg.nontype]/1
5308
5309 A template-argument for a non-type, non-template template-parameter
5310 shall be one of:
5311 [...]
5312 -- the address of an object or function with external [C++11: or
5313 internal] linkage. */
5314
5315 if (TREE_CODE (fn_no_ptr) != FUNCTION_DECL)
5316 {
5317 error ("%qE is not a valid template argument for type %qT", expr, type);
5318 if (TYPE_PTR_P (type))
5319 error ("it must be the address of a function with external linkage");
5320 else
5321 error ("it must be the name of a function with external linkage");
5322 return NULL_TREE;
5323 }
5324
5325 linkage = decl_linkage (fn_no_ptr);
5326 if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external)
5327 {
5328 if (cxx_dialect >= cxx11)
5329 error ("%qE is not a valid template argument for type %qT "
5330 "because %qD has no linkage",
5331 expr, type, fn_no_ptr);
5332 else
5333 error ("%qE is not a valid template argument for type %qT "
5334 "because %qD does not have external linkage",
5335 expr, type, fn_no_ptr);
5336 return NULL_TREE;
5337 }
5338
5339 return fn;
5340 }
5341
5342 /* Subroutine of convert_nontype_argument.
5343 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5344 Emit an error otherwise. */
5345
5346 static bool
check_valid_ptrmem_cst_expr(tree type,tree expr,tsubst_flags_t complain)5347 check_valid_ptrmem_cst_expr (tree type, tree expr,
5348 tsubst_flags_t complain)
5349 {
5350 STRIP_NOPS (expr);
5351 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5352 return true;
5353 if (cxx_dialect >= cxx11 && null_member_pointer_value_p (expr))
5354 return true;
5355 if (processing_template_decl
5356 && TREE_CODE (expr) == ADDR_EXPR
5357 && TREE_CODE (TREE_OPERAND (expr, 0)) == OFFSET_REF)
5358 return true;
5359 if (complain & tf_error)
5360 {
5361 error ("%qE is not a valid template argument for type %qT",
5362 expr, type);
5363 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5364 }
5365 return false;
5366 }
5367
5368 /* Returns TRUE iff the address of OP is value-dependent.
5369
5370 14.6.2.4 [temp.dep.temp]:
5371 A non-integral non-type template-argument is dependent if its type is
5372 dependent or it has either of the following forms
5373 qualified-id
5374 & qualified-id
5375 and contains a nested-name-specifier which specifies a class-name that
5376 names a dependent type.
5377
5378 We generalize this to just say that the address of a member of a
5379 dependent class is value-dependent; the above doesn't cover the
5380 address of a static data member named with an unqualified-id. */
5381
5382 static bool
has_value_dependent_address(tree op)5383 has_value_dependent_address (tree op)
5384 {
5385 /* We could use get_inner_reference here, but there's no need;
5386 this is only relevant for template non-type arguments, which
5387 can only be expressed as &id-expression. */
5388 if (DECL_P (op))
5389 {
5390 tree ctx = CP_DECL_CONTEXT (op);
5391 if (TYPE_P (ctx) && dependent_type_p (ctx))
5392 return true;
5393 }
5394
5395 return false;
5396 }
5397
5398 /* The next set of functions are used for providing helpful explanatory
5399 diagnostics for failed overload resolution. Their messages should be
5400 indented by two spaces for consistency with the messages in
5401 call.c */
5402
5403 static int
unify_success(bool)5404 unify_success (bool /*explain_p*/)
5405 {
5406 return 0;
5407 }
5408
5409 static int
unify_parameter_deduction_failure(bool explain_p,tree parm)5410 unify_parameter_deduction_failure (bool explain_p, tree parm)
5411 {
5412 if (explain_p)
5413 inform (input_location,
5414 " couldn't deduce template parameter %qD", parm);
5415 return 1;
5416 }
5417
5418 static int
unify_invalid(bool)5419 unify_invalid (bool /*explain_p*/)
5420 {
5421 return 1;
5422 }
5423
5424 static int
unify_cv_qual_mismatch(bool explain_p,tree parm,tree arg)5425 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5426 {
5427 if (explain_p)
5428 inform (input_location,
5429 " types %qT and %qT have incompatible cv-qualifiers",
5430 parm, arg);
5431 return 1;
5432 }
5433
5434 static int
unify_type_mismatch(bool explain_p,tree parm,tree arg)5435 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5436 {
5437 if (explain_p)
5438 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5439 return 1;
5440 }
5441
5442 static int
unify_parameter_pack_mismatch(bool explain_p,tree parm,tree arg)5443 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5444 {
5445 if (explain_p)
5446 inform (input_location,
5447 " template parameter %qD is not a parameter pack, but "
5448 "argument %qD is",
5449 parm, arg);
5450 return 1;
5451 }
5452
5453 static int
unify_ptrmem_cst_mismatch(bool explain_p,tree parm,tree arg)5454 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5455 {
5456 if (explain_p)
5457 inform (input_location,
5458 " template argument %qE does not match "
5459 "pointer-to-member constant %qE",
5460 arg, parm);
5461 return 1;
5462 }
5463
5464 static int
unify_expression_unequal(bool explain_p,tree parm,tree arg)5465 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5466 {
5467 if (explain_p)
5468 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5469 return 1;
5470 }
5471
5472 static int
unify_parameter_pack_inconsistent(bool explain_p,tree old_arg,tree new_arg)5473 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5474 {
5475 if (explain_p)
5476 inform (input_location,
5477 " inconsistent parameter pack deduction with %qT and %qT",
5478 old_arg, new_arg);
5479 return 1;
5480 }
5481
5482 static int
unify_inconsistency(bool explain_p,tree parm,tree first,tree second)5483 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5484 {
5485 if (explain_p)
5486 {
5487 if (TYPE_P (parm))
5488 inform (input_location,
5489 " deduced conflicting types for parameter %qT (%qT and %qT)",
5490 parm, first, second);
5491 else
5492 inform (input_location,
5493 " deduced conflicting values for non-type parameter "
5494 "%qE (%qE and %qE)", parm, first, second);
5495 }
5496 return 1;
5497 }
5498
5499 static int
unify_vla_arg(bool explain_p,tree arg)5500 unify_vla_arg (bool explain_p, tree arg)
5501 {
5502 if (explain_p)
5503 inform (input_location,
5504 " variable-sized array type %qT is not "
5505 "a valid template argument",
5506 arg);
5507 return 1;
5508 }
5509
5510 static int
unify_method_type_error(bool explain_p,tree arg)5511 unify_method_type_error (bool explain_p, tree arg)
5512 {
5513 if (explain_p)
5514 inform (input_location,
5515 " member function type %qT is not a valid template argument",
5516 arg);
5517 return 1;
5518 }
5519
5520 static int
unify_arity(bool explain_p,int have,int wanted)5521 unify_arity (bool explain_p, int have, int wanted)
5522 {
5523 if (explain_p)
5524 inform_n (input_location, wanted,
5525 " candidate expects %d argument, %d provided",
5526 " candidate expects %d arguments, %d provided",
5527 wanted, have);
5528 return 1;
5529 }
5530
5531 static int
unify_too_many_arguments(bool explain_p,int have,int wanted)5532 unify_too_many_arguments (bool explain_p, int have, int wanted)
5533 {
5534 return unify_arity (explain_p, have, wanted);
5535 }
5536
5537 static int
unify_too_few_arguments(bool explain_p,int have,int wanted)5538 unify_too_few_arguments (bool explain_p, int have, int wanted)
5539 {
5540 return unify_arity (explain_p, have, wanted);
5541 }
5542
5543 static int
unify_arg_conversion(bool explain_p,tree to_type,tree from_type,tree arg)5544 unify_arg_conversion (bool explain_p, tree to_type,
5545 tree from_type, tree arg)
5546 {
5547 if (explain_p)
5548 inform (EXPR_LOC_OR_LOC (arg, input_location),
5549 " cannot convert %qE (type %qT) to type %qT",
5550 arg, from_type, to_type);
5551 return 1;
5552 }
5553
5554 static int
unify_no_common_base(bool explain_p,enum template_base_result r,tree parm,tree arg)5555 unify_no_common_base (bool explain_p, enum template_base_result r,
5556 tree parm, tree arg)
5557 {
5558 if (explain_p)
5559 switch (r)
5560 {
5561 case tbr_ambiguous_baseclass:
5562 inform (input_location, " %qT is an ambiguous base class of %qT",
5563 parm, arg);
5564 break;
5565 default:
5566 inform (input_location, " %qT is not derived from %qT", arg, parm);
5567 break;
5568 }
5569 return 1;
5570 }
5571
5572 static int
unify_inconsistent_template_template_parameters(bool explain_p)5573 unify_inconsistent_template_template_parameters (bool explain_p)
5574 {
5575 if (explain_p)
5576 inform (input_location,
5577 " template parameters of a template template argument are "
5578 "inconsistent with other deduced template arguments");
5579 return 1;
5580 }
5581
5582 static int
unify_template_deduction_failure(bool explain_p,tree parm,tree arg)5583 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5584 {
5585 if (explain_p)
5586 inform (input_location,
5587 " can't deduce a template for %qT from non-template type %qT",
5588 parm, arg);
5589 return 1;
5590 }
5591
5592 static int
unify_template_argument_mismatch(bool explain_p,tree parm,tree arg)5593 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5594 {
5595 if (explain_p)
5596 inform (input_location,
5597 " template argument %qE does not match %qD", arg, parm);
5598 return 1;
5599 }
5600
5601 static int
unify_overload_resolution_failure(bool explain_p,tree arg)5602 unify_overload_resolution_failure (bool explain_p, tree arg)
5603 {
5604 if (explain_p)
5605 inform (input_location,
5606 " could not resolve address from overloaded function %qE",
5607 arg);
5608 return 1;
5609 }
5610
5611 /* Attempt to convert the non-type template parameter EXPR to the
5612 indicated TYPE. If the conversion is successful, return the
5613 converted value. If the conversion is unsuccessful, return
5614 NULL_TREE if we issued an error message, or error_mark_node if we
5615 did not. We issue error messages for out-and-out bad template
5616 parameters, but not simply because the conversion failed, since we
5617 might be just trying to do argument deduction. Both TYPE and EXPR
5618 must be non-dependent.
5619
5620 The conversion follows the special rules described in
5621 [temp.arg.nontype], and it is much more strict than an implicit
5622 conversion.
5623
5624 This function is called twice for each template argument (see
5625 lookup_template_class for a more accurate description of this
5626 problem). This means that we need to handle expressions which
5627 are not valid in a C++ source, but can be created from the
5628 first call (for instance, casts to perform conversions). These
5629 hacks can go away after we fix the double coercion problem. */
5630
5631 static tree
convert_nontype_argument(tree type,tree expr,tsubst_flags_t complain)5632 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5633 {
5634 tree expr_type;
5635
5636 /* Detect immediately string literals as invalid non-type argument.
5637 This special-case is not needed for correctness (we would easily
5638 catch this later), but only to provide better diagnostic for this
5639 common user mistake. As suggested by DR 100, we do not mention
5640 linkage issues in the diagnostic as this is not the point. */
5641 /* FIXME we're making this OK. */
5642 if (TREE_CODE (expr) == STRING_CST)
5643 {
5644 if (complain & tf_error)
5645 error ("%qE is not a valid template argument for type %qT "
5646 "because string literals can never be used in this context",
5647 expr, type);
5648 return NULL_TREE;
5649 }
5650
5651 /* Add the ADDR_EXPR now for the benefit of
5652 value_dependent_expression_p. */
5653 if (TYPE_PTROBV_P (type)
5654 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5655 {
5656 expr = decay_conversion (expr, complain);
5657 if (expr == error_mark_node)
5658 return error_mark_node;
5659 }
5660
5661 /* If we are in a template, EXPR may be non-dependent, but still
5662 have a syntactic, rather than semantic, form. For example, EXPR
5663 might be a SCOPE_REF, rather than the VAR_DECL to which the
5664 SCOPE_REF refers. Preserving the qualifying scope is necessary
5665 so that access checking can be performed when the template is
5666 instantiated -- but here we need the resolved form so that we can
5667 convert the argument. */
5668 if (TYPE_REF_OBJ_P (type)
5669 && has_value_dependent_address (expr))
5670 /* If we want the address and it's value-dependent, don't fold. */;
5671 else if (!type_unknown_p (expr))
5672 expr = fold_non_dependent_expr_sfinae (expr, complain);
5673 if (error_operand_p (expr))
5674 return error_mark_node;
5675 expr_type = TREE_TYPE (expr);
5676 if (TREE_CODE (type) == REFERENCE_TYPE)
5677 expr = mark_lvalue_use (expr);
5678 else
5679 expr = mark_rvalue_use (expr);
5680
5681 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5682 to a non-type argument of "nullptr". */
5683 if (expr == nullptr_node && TYPE_PTR_OR_PTRMEM_P (type))
5684 expr = convert (type, expr);
5685
5686 /* In C++11, integral or enumeration non-type template arguments can be
5687 arbitrary constant expressions. Pointer and pointer to
5688 member arguments can be general constant expressions that evaluate
5689 to a null value, but otherwise still need to be of a specific form. */
5690 if (cxx_dialect >= cxx11)
5691 {
5692 if (TREE_CODE (expr) == PTRMEM_CST)
5693 /* A PTRMEM_CST is already constant, and a valid template
5694 argument for a parameter of pointer to member type, we just want
5695 to leave it in that form rather than lower it to a
5696 CONSTRUCTOR. */;
5697 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5698 expr = maybe_constant_value (expr);
5699 else if (TYPE_PTR_OR_PTRMEM_P (type))
5700 {
5701 tree folded = maybe_constant_value (expr);
5702 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5703 : null_member_pointer_value_p (folded))
5704 expr = folded;
5705 }
5706 }
5707
5708 /* HACK: Due to double coercion, we can get a
5709 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5710 which is the tree that we built on the first call (see
5711 below when coercing to reference to object or to reference to
5712 function). We just strip everything and get to the arg.
5713 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5714 for examples. */
5715 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5716 {
5717 tree probe_type, probe = expr;
5718 if (REFERENCE_REF_P (probe))
5719 probe = TREE_OPERAND (probe, 0);
5720 probe_type = TREE_TYPE (probe);
5721 if (TREE_CODE (probe) == NOP_EXPR)
5722 {
5723 /* ??? Maybe we could use convert_from_reference here, but we
5724 would need to relax its constraints because the NOP_EXPR
5725 could actually change the type to something more cv-qualified,
5726 and this is not folded by convert_from_reference. */
5727 tree addr = TREE_OPERAND (probe, 0);
5728 if (TREE_CODE (probe_type) == REFERENCE_TYPE
5729 && TREE_CODE (addr) == ADDR_EXPR
5730 && TYPE_PTR_P (TREE_TYPE (addr))
5731 && (same_type_ignoring_top_level_qualifiers_p
5732 (TREE_TYPE (probe_type),
5733 TREE_TYPE (TREE_TYPE (addr)))))
5734 {
5735 expr = TREE_OPERAND (addr, 0);
5736 expr_type = TREE_TYPE (probe_type);
5737 }
5738 }
5739 }
5740
5741 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5742 parameter is a pointer to object, through decay and
5743 qualification conversion. Let's strip everything. */
5744 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5745 {
5746 tree probe = expr;
5747 STRIP_NOPS (probe);
5748 if (TREE_CODE (probe) == ADDR_EXPR
5749 && TYPE_PTR_P (TREE_TYPE (probe)))
5750 {
5751 /* Skip the ADDR_EXPR only if it is part of the decay for
5752 an array. Otherwise, it is part of the original argument
5753 in the source code. */
5754 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (probe, 0))) == ARRAY_TYPE)
5755 probe = TREE_OPERAND (probe, 0);
5756 expr = probe;
5757 expr_type = TREE_TYPE (expr);
5758 }
5759 }
5760
5761 /* [temp.arg.nontype]/5, bullet 1
5762
5763 For a non-type template-parameter of integral or enumeration type,
5764 integral promotions (_conv.prom_) and integral conversions
5765 (_conv.integral_) are applied. */
5766 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5767 {
5768 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5769 t = maybe_constant_value (t);
5770 if (t != error_mark_node)
5771 expr = t;
5772
5773 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5774 return error_mark_node;
5775
5776 /* Notice that there are constant expressions like '4 % 0' which
5777 do not fold into integer constants. */
5778 if (TREE_CODE (expr) != INTEGER_CST)
5779 {
5780 if (complain & tf_error)
5781 {
5782 int errs = errorcount, warns = warningcount + werrorcount;
5783 if (processing_template_decl
5784 && !require_potential_constant_expression (expr))
5785 return NULL_TREE;
5786 expr = cxx_constant_value (expr);
5787 if (errorcount > errs || warningcount + werrorcount > warns)
5788 inform (EXPR_LOC_OR_LOC (expr, input_location),
5789 "in template argument for type %qT ", type);
5790 if (expr == error_mark_node)
5791 return NULL_TREE;
5792 /* else cxx_constant_value complained but gave us
5793 a real constant, so go ahead. */
5794 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5795 }
5796 else
5797 return NULL_TREE;
5798 }
5799
5800 /* Avoid typedef problems. */
5801 if (TREE_TYPE (expr) != type)
5802 expr = fold_convert (type, expr);
5803 }
5804 /* [temp.arg.nontype]/5, bullet 2
5805
5806 For a non-type template-parameter of type pointer to object,
5807 qualification conversions (_conv.qual_) and the array-to-pointer
5808 conversion (_conv.array_) are applied. */
5809 else if (TYPE_PTROBV_P (type))
5810 {
5811 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5812
5813 A template-argument for a non-type, non-template template-parameter
5814 shall be one of: [...]
5815
5816 -- the name of a non-type template-parameter;
5817 -- the address of an object or function with external linkage, [...]
5818 expressed as "& id-expression" where the & is optional if the name
5819 refers to a function or array, or if the corresponding
5820 template-parameter is a reference.
5821
5822 Here, we do not care about functions, as they are invalid anyway
5823 for a parameter of type pointer-to-object. */
5824
5825 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5826 /* Non-type template parameters are OK. */
5827 ;
5828 else if (cxx_dialect >= cxx11 && integer_zerop (expr))
5829 /* Null pointer values are OK in C++11. */;
5830 else if (TREE_CODE (expr) != ADDR_EXPR
5831 && TREE_CODE (expr_type) != ARRAY_TYPE)
5832 {
5833 if (VAR_P (expr))
5834 {
5835 if (complain & tf_error)
5836 error ("%qD is not a valid template argument "
5837 "because %qD is a variable, not the address of "
5838 "a variable", expr, expr);
5839 return NULL_TREE;
5840 }
5841 if (POINTER_TYPE_P (expr_type))
5842 {
5843 if (complain & tf_error)
5844 error ("%qE is not a valid template argument for %qT "
5845 "because it is not the address of a variable",
5846 expr, type);
5847 return NULL_TREE;
5848 }
5849 /* Other values, like integer constants, might be valid
5850 non-type arguments of some other type. */
5851 return error_mark_node;
5852 }
5853 else
5854 {
5855 tree decl;
5856
5857 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5858 ? TREE_OPERAND (expr, 0) : expr);
5859 if (!VAR_P (decl))
5860 {
5861 if (complain & tf_error)
5862 error ("%qE is not a valid template argument of type %qT "
5863 "because %qE is not a variable", expr, type, decl);
5864 return NULL_TREE;
5865 }
5866 else if (cxx_dialect < cxx11 && !DECL_EXTERNAL_LINKAGE_P (decl))
5867 {
5868 if (complain & tf_error)
5869 error ("%qE is not a valid template argument of type %qT "
5870 "because %qD does not have external linkage",
5871 expr, type, decl);
5872 return NULL_TREE;
5873 }
5874 else if (cxx_dialect >= cxx11 && decl_linkage (decl) == lk_none)
5875 {
5876 if (complain & tf_error)
5877 error ("%qE is not a valid template argument of type %qT "
5878 "because %qD has no linkage", expr, type, decl);
5879 return NULL_TREE;
5880 }
5881 }
5882
5883 expr = decay_conversion (expr, complain);
5884 if (expr == error_mark_node)
5885 return error_mark_node;
5886
5887 expr = perform_qualification_conversions (type, expr);
5888 if (expr == error_mark_node)
5889 return error_mark_node;
5890 }
5891 /* [temp.arg.nontype]/5, bullet 3
5892
5893 For a non-type template-parameter of type reference to object, no
5894 conversions apply. The type referred to by the reference may be more
5895 cv-qualified than the (otherwise identical) type of the
5896 template-argument. The template-parameter is bound directly to the
5897 template-argument, which must be an lvalue. */
5898 else if (TYPE_REF_OBJ_P (type))
5899 {
5900 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5901 expr_type))
5902 return error_mark_node;
5903
5904 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5905 {
5906 if (complain & tf_error)
5907 error ("%qE is not a valid template argument for type %qT "
5908 "because of conflicts in cv-qualification", expr, type);
5909 return NULL_TREE;
5910 }
5911
5912 if (!real_lvalue_p (expr))
5913 {
5914 if (complain & tf_error)
5915 error ("%qE is not a valid template argument for type %qT "
5916 "because it is not an lvalue", expr, type);
5917 return NULL_TREE;
5918 }
5919
5920 /* [temp.arg.nontype]/1
5921
5922 A template-argument for a non-type, non-template template-parameter
5923 shall be one of: [...]
5924
5925 -- the address of an object or function with external linkage. */
5926 if (INDIRECT_REF_P (expr)
5927 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5928 {
5929 expr = TREE_OPERAND (expr, 0);
5930 if (DECL_P (expr))
5931 {
5932 if (complain & tf_error)
5933 error ("%q#D is not a valid template argument for type %qT "
5934 "because a reference variable does not have a constant "
5935 "address", expr, type);
5936 return NULL_TREE;
5937 }
5938 }
5939
5940 if (!DECL_P (expr))
5941 {
5942 if (complain & tf_error)
5943 error ("%qE is not a valid template argument for type %qT "
5944 "because it is not an object with external linkage",
5945 expr, type);
5946 return NULL_TREE;
5947 }
5948
5949 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5950 {
5951 if (complain & tf_error)
5952 error ("%qE is not a valid template argument for type %qT "
5953 "because object %qD has not external linkage",
5954 expr, type, expr);
5955 return NULL_TREE;
5956 }
5957
5958 expr = build_nop (type, build_address (expr));
5959 }
5960 /* [temp.arg.nontype]/5, bullet 4
5961
5962 For a non-type template-parameter of type pointer to function, only
5963 the function-to-pointer conversion (_conv.func_) is applied. If the
5964 template-argument represents a set of overloaded functions (or a
5965 pointer to such), the matching function is selected from the set
5966 (_over.over_). */
5967 else if (TYPE_PTRFN_P (type))
5968 {
5969 /* If the argument is a template-id, we might not have enough
5970 context information to decay the pointer. */
5971 if (!type_unknown_p (expr_type))
5972 {
5973 expr = decay_conversion (expr, complain);
5974 if (expr == error_mark_node)
5975 return error_mark_node;
5976 }
5977
5978 if (cxx_dialect >= cxx11 && integer_zerop (expr))
5979 /* Null pointer values are OK in C++11. */
5980 return perform_qualification_conversions (type, expr);
5981
5982 expr = convert_nontype_argument_function (type, expr);
5983 if (!expr || expr == error_mark_node)
5984 return expr;
5985 }
5986 /* [temp.arg.nontype]/5, bullet 5
5987
5988 For a non-type template-parameter of type reference to function, no
5989 conversions apply. If the template-argument represents a set of
5990 overloaded functions, the matching function is selected from the set
5991 (_over.over_). */
5992 else if (TYPE_REFFN_P (type))
5993 {
5994 if (TREE_CODE (expr) == ADDR_EXPR)
5995 {
5996 if (complain & tf_error)
5997 {
5998 error ("%qE is not a valid template argument for type %qT "
5999 "because it is a pointer", expr, type);
6000 inform (input_location, "try using %qE instead",
6001 TREE_OPERAND (expr, 0));
6002 }
6003 return NULL_TREE;
6004 }
6005
6006 expr = convert_nontype_argument_function (type, expr);
6007 if (!expr || expr == error_mark_node)
6008 return expr;
6009
6010 expr = build_nop (type, build_address (expr));
6011 }
6012 /* [temp.arg.nontype]/5, bullet 6
6013
6014 For a non-type template-parameter of type pointer to member function,
6015 no conversions apply. If the template-argument represents a set of
6016 overloaded member functions, the matching member function is selected
6017 from the set (_over.over_). */
6018 else if (TYPE_PTRMEMFUNC_P (type))
6019 {
6020 expr = instantiate_type (type, expr, tf_none);
6021 if (expr == error_mark_node)
6022 return error_mark_node;
6023
6024 /* [temp.arg.nontype] bullet 1 says the pointer to member
6025 expression must be a pointer-to-member constant. */
6026 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6027 return error_mark_node;
6028
6029 /* There is no way to disable standard conversions in
6030 resolve_address_of_overloaded_function (called by
6031 instantiate_type). It is possible that the call succeeded by
6032 converting &B::I to &D::I (where B is a base of D), so we need
6033 to reject this conversion here.
6034
6035 Actually, even if there was a way to disable standard conversions,
6036 it would still be better to reject them here so that we can
6037 provide a superior diagnostic. */
6038 if (!same_type_p (TREE_TYPE (expr), type))
6039 {
6040 if (complain & tf_error)
6041 {
6042 error ("%qE is not a valid template argument for type %qT "
6043 "because it is of type %qT", expr, type,
6044 TREE_TYPE (expr));
6045 /* If we are just one standard conversion off, explain. */
6046 if (can_convert_standard (type, TREE_TYPE (expr), complain))
6047 inform (input_location,
6048 "standard conversions are not allowed in this context");
6049 }
6050 return NULL_TREE;
6051 }
6052 }
6053 /* [temp.arg.nontype]/5, bullet 7
6054
6055 For a non-type template-parameter of type pointer to data member,
6056 qualification conversions (_conv.qual_) are applied. */
6057 else if (TYPE_PTRDATAMEM_P (type))
6058 {
6059 /* [temp.arg.nontype] bullet 1 says the pointer to member
6060 expression must be a pointer-to-member constant. */
6061 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6062 return error_mark_node;
6063
6064 expr = perform_qualification_conversions (type, expr);
6065 if (expr == error_mark_node)
6066 return expr;
6067 }
6068 else if (NULLPTR_TYPE_P (type))
6069 {
6070 if (expr != nullptr_node)
6071 {
6072 if (complain & tf_error)
6073 error ("%qE is not a valid template argument for type %qT "
6074 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6075 return NULL_TREE;
6076 }
6077 return expr;
6078 }
6079 /* A template non-type parameter must be one of the above. */
6080 else
6081 gcc_unreachable ();
6082
6083 /* Sanity check: did we actually convert the argument to the
6084 right type? */
6085 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6086 (type, TREE_TYPE (expr)));
6087 return expr;
6088 }
6089
6090 /* Subroutine of coerce_template_template_parms, which returns 1 if
6091 PARM_PARM and ARG_PARM match using the rule for the template
6092 parameters of template template parameters. Both PARM and ARG are
6093 template parameters; the rest of the arguments are the same as for
6094 coerce_template_template_parms.
6095 */
6096 static int
coerce_template_template_parm(tree parm,tree arg,tsubst_flags_t complain,tree in_decl,tree outer_args)6097 coerce_template_template_parm (tree parm,
6098 tree arg,
6099 tsubst_flags_t complain,
6100 tree in_decl,
6101 tree outer_args)
6102 {
6103 if (arg == NULL_TREE || error_operand_p (arg)
6104 || parm == NULL_TREE || error_operand_p (parm))
6105 return 0;
6106
6107 if (TREE_CODE (arg) != TREE_CODE (parm))
6108 return 0;
6109
6110 switch (TREE_CODE (parm))
6111 {
6112 case TEMPLATE_DECL:
6113 /* We encounter instantiations of templates like
6114 template <template <template <class> class> class TT>
6115 class C; */
6116 {
6117 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6118 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6119
6120 if (!coerce_template_template_parms
6121 (parmparm, argparm, complain, in_decl, outer_args))
6122 return 0;
6123 }
6124 /* Fall through. */
6125
6126 case TYPE_DECL:
6127 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6128 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6129 /* Argument is a parameter pack but parameter is not. */
6130 return 0;
6131 break;
6132
6133 case PARM_DECL:
6134 /* The tsubst call is used to handle cases such as
6135
6136 template <int> class C {};
6137 template <class T, template <T> class TT> class D {};
6138 D<int, C> d;
6139
6140 i.e. the parameter list of TT depends on earlier parameters. */
6141 if (!uses_template_parms (TREE_TYPE (arg))
6142 && !same_type_p
6143 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6144 TREE_TYPE (arg)))
6145 return 0;
6146
6147 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6148 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6149 /* Argument is a parameter pack but parameter is not. */
6150 return 0;
6151
6152 break;
6153
6154 default:
6155 gcc_unreachable ();
6156 }
6157
6158 return 1;
6159 }
6160
6161
6162 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6163 template template parameters. Both PARM_PARMS and ARG_PARMS are
6164 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6165 or PARM_DECL.
6166
6167 Consider the example:
6168 template <class T> class A;
6169 template<template <class U> class TT> class B;
6170
6171 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6172 the parameters to A, and OUTER_ARGS contains A. */
6173
6174 static int
coerce_template_template_parms(tree parm_parms,tree arg_parms,tsubst_flags_t complain,tree in_decl,tree outer_args)6175 coerce_template_template_parms (tree parm_parms,
6176 tree arg_parms,
6177 tsubst_flags_t complain,
6178 tree in_decl,
6179 tree outer_args)
6180 {
6181 int nparms, nargs, i;
6182 tree parm, arg;
6183 int variadic_p = 0;
6184
6185 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6186 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6187
6188 nparms = TREE_VEC_LENGTH (parm_parms);
6189 nargs = TREE_VEC_LENGTH (arg_parms);
6190
6191 /* Determine whether we have a parameter pack at the end of the
6192 template template parameter's template parameter list. */
6193 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6194 {
6195 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6196
6197 if (error_operand_p (parm))
6198 return 0;
6199
6200 switch (TREE_CODE (parm))
6201 {
6202 case TEMPLATE_DECL:
6203 case TYPE_DECL:
6204 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6205 variadic_p = 1;
6206 break;
6207
6208 case PARM_DECL:
6209 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6210 variadic_p = 1;
6211 break;
6212
6213 default:
6214 gcc_unreachable ();
6215 }
6216 }
6217
6218 if (nargs != nparms
6219 && !(variadic_p && nargs >= nparms - 1))
6220 return 0;
6221
6222 /* Check all of the template parameters except the parameter pack at
6223 the end (if any). */
6224 for (i = 0; i < nparms - variadic_p; ++i)
6225 {
6226 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6227 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6228 continue;
6229
6230 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6231 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6232
6233 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6234 outer_args))
6235 return 0;
6236
6237 }
6238
6239 if (variadic_p)
6240 {
6241 /* Check each of the template parameters in the template
6242 argument against the template parameter pack at the end of
6243 the template template parameter. */
6244 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6245 return 0;
6246
6247 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6248
6249 for (; i < nargs; ++i)
6250 {
6251 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6252 continue;
6253
6254 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6255
6256 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6257 outer_args))
6258 return 0;
6259 }
6260 }
6261
6262 return 1;
6263 }
6264
6265 /* Verifies that the deduced template arguments (in TARGS) for the
6266 template template parameters (in TPARMS) represent valid bindings,
6267 by comparing the template parameter list of each template argument
6268 to the template parameter list of its corresponding template
6269 template parameter, in accordance with DR150. This
6270 routine can only be called after all template arguments have been
6271 deduced. It will return TRUE if all of the template template
6272 parameter bindings are okay, FALSE otherwise. */
6273 bool
template_template_parm_bindings_ok_p(tree tparms,tree targs)6274 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6275 {
6276 int i, ntparms = TREE_VEC_LENGTH (tparms);
6277 bool ret = true;
6278
6279 /* We're dealing with template parms in this process. */
6280 ++processing_template_decl;
6281
6282 targs = INNERMOST_TEMPLATE_ARGS (targs);
6283
6284 for (i = 0; i < ntparms; ++i)
6285 {
6286 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6287 tree targ = TREE_VEC_ELT (targs, i);
6288
6289 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6290 {
6291 tree packed_args = NULL_TREE;
6292 int idx, len = 1;
6293
6294 if (ARGUMENT_PACK_P (targ))
6295 {
6296 /* Look inside the argument pack. */
6297 packed_args = ARGUMENT_PACK_ARGS (targ);
6298 len = TREE_VEC_LENGTH (packed_args);
6299 }
6300
6301 for (idx = 0; idx < len; ++idx)
6302 {
6303 tree targ_parms = NULL_TREE;
6304
6305 if (packed_args)
6306 /* Extract the next argument from the argument
6307 pack. */
6308 targ = TREE_VEC_ELT (packed_args, idx);
6309
6310 if (PACK_EXPANSION_P (targ))
6311 /* Look at the pattern of the pack expansion. */
6312 targ = PACK_EXPANSION_PATTERN (targ);
6313
6314 /* Extract the template parameters from the template
6315 argument. */
6316 if (TREE_CODE (targ) == TEMPLATE_DECL)
6317 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6318 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6319 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6320
6321 /* Verify that we can coerce the template template
6322 parameters from the template argument to the template
6323 parameter. This requires an exact match. */
6324 if (targ_parms
6325 && !coerce_template_template_parms
6326 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6327 targ_parms,
6328 tf_none,
6329 tparm,
6330 targs))
6331 {
6332 ret = false;
6333 goto out;
6334 }
6335 }
6336 }
6337 }
6338
6339 out:
6340
6341 --processing_template_decl;
6342 return ret;
6343 }
6344
6345 /* Since type attributes aren't mangled, we need to strip them from
6346 template type arguments. */
6347
6348 static tree
canonicalize_type_argument(tree arg,tsubst_flags_t complain)6349 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6350 {
6351 tree mv;
6352 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6353 return arg;
6354 mv = TYPE_MAIN_VARIANT (arg);
6355 arg = strip_typedefs (arg);
6356 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6357 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6358 {
6359 if (complain & tf_warning)
6360 warning (0, "ignoring attributes on template argument %qT", arg);
6361 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6362 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6363 }
6364 return arg;
6365 }
6366
6367 /* Convert the indicated template ARG as necessary to match the
6368 indicated template PARM. Returns the converted ARG, or
6369 error_mark_node if the conversion was unsuccessful. Error and
6370 warning messages are issued under control of COMPLAIN. This
6371 conversion is for the Ith parameter in the parameter list. ARGS is
6372 the full set of template arguments deduced so far. */
6373
6374 static tree
convert_template_argument(tree parm,tree arg,tree args,tsubst_flags_t complain,int i,tree in_decl)6375 convert_template_argument (tree parm,
6376 tree arg,
6377 tree args,
6378 tsubst_flags_t complain,
6379 int i,
6380 tree in_decl)
6381 {
6382 tree orig_arg;
6383 tree val;
6384 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6385
6386 if (TREE_CODE (arg) == TREE_LIST
6387 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6388 {
6389 /* The template argument was the name of some
6390 member function. That's usually
6391 invalid, but static members are OK. In any
6392 case, grab the underlying fields/functions
6393 and issue an error later if required. */
6394 orig_arg = TREE_VALUE (arg);
6395 TREE_TYPE (arg) = unknown_type_node;
6396 }
6397
6398 orig_arg = arg;
6399
6400 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6401 requires_type = (TREE_CODE (parm) == TYPE_DECL
6402 || requires_tmpl_type);
6403
6404 /* When determining whether an argument pack expansion is a template,
6405 look at the pattern. */
6406 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6407 arg = PACK_EXPANSION_PATTERN (arg);
6408
6409 /* Deal with an injected-class-name used as a template template arg. */
6410 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6411 {
6412 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6413 if (TREE_CODE (t) == TEMPLATE_DECL)
6414 {
6415 if (cxx_dialect >= cxx11)
6416 /* OK under DR 1004. */;
6417 else if (complain & tf_warning_or_error)
6418 pedwarn (input_location, OPT_Wpedantic, "injected-class-name %qD"
6419 " used as template template argument", TYPE_NAME (arg));
6420 else if (flag_pedantic_errors)
6421 t = arg;
6422
6423 arg = t;
6424 }
6425 }
6426
6427 is_tmpl_type =
6428 ((TREE_CODE (arg) == TEMPLATE_DECL
6429 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6430 || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK)
6431 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6432 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6433
6434 if (is_tmpl_type
6435 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6436 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6437 arg = TYPE_STUB_DECL (arg);
6438
6439 is_type = TYPE_P (arg) || is_tmpl_type;
6440
6441 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6442 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6443 {
6444 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6445 {
6446 if (complain & tf_error)
6447 error ("invalid use of destructor %qE as a type", orig_arg);
6448 return error_mark_node;
6449 }
6450
6451 permerror (input_location,
6452 "to refer to a type member of a template parameter, "
6453 "use %<typename %E%>", orig_arg);
6454
6455 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6456 TREE_OPERAND (arg, 1),
6457 typename_type,
6458 complain);
6459 arg = orig_arg;
6460 is_type = 1;
6461 }
6462 if (is_type != requires_type)
6463 {
6464 if (in_decl)
6465 {
6466 if (complain & tf_error)
6467 {
6468 error ("type/value mismatch at argument %d in template "
6469 "parameter list for %qD",
6470 i + 1, in_decl);
6471 if (is_type)
6472 error (" expected a constant of type %qT, got %qT",
6473 TREE_TYPE (parm),
6474 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6475 else if (requires_tmpl_type)
6476 error (" expected a class template, got %qE", orig_arg);
6477 else
6478 error (" expected a type, got %qE", orig_arg);
6479 }
6480 }
6481 return error_mark_node;
6482 }
6483 if (is_tmpl_type ^ requires_tmpl_type)
6484 {
6485 if (in_decl && (complain & tf_error))
6486 {
6487 error ("type/value mismatch at argument %d in template "
6488 "parameter list for %qD",
6489 i + 1, in_decl);
6490 if (is_tmpl_type)
6491 error (" expected a type, got %qT", DECL_NAME (arg));
6492 else
6493 error (" expected a class template, got %qT", orig_arg);
6494 }
6495 return error_mark_node;
6496 }
6497
6498 if (is_type)
6499 {
6500 if (requires_tmpl_type)
6501 {
6502 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6503 val = orig_arg;
6504 else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6505 /* The number of argument required is not known yet.
6506 Just accept it for now. */
6507 val = TREE_TYPE (arg);
6508 else
6509 {
6510 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6511 tree argparm;
6512
6513 /* Strip alias templates that are equivalent to another
6514 template. */
6515 arg = get_underlying_template (arg);
6516 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6517
6518 if (coerce_template_template_parms (parmparm, argparm,
6519 complain, in_decl,
6520 args))
6521 {
6522 val = arg;
6523
6524 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6525 TEMPLATE_DECL. */
6526 if (val != error_mark_node)
6527 {
6528 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6529 val = TREE_TYPE (val);
6530 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6531 val = make_pack_expansion (val);
6532 }
6533 }
6534 else
6535 {
6536 if (in_decl && (complain & tf_error))
6537 {
6538 error ("type/value mismatch at argument %d in "
6539 "template parameter list for %qD",
6540 i + 1, in_decl);
6541 error (" expected a template of type %qD, got %qT",
6542 parm, orig_arg);
6543 }
6544
6545 val = error_mark_node;
6546 }
6547 }
6548 }
6549 else
6550 val = orig_arg;
6551 /* We only form one instance of each template specialization.
6552 Therefore, if we use a non-canonical variant (i.e., a
6553 typedef), any future messages referring to the type will use
6554 the typedef, which is confusing if those future uses do not
6555 themselves also use the typedef. */
6556 if (TYPE_P (val))
6557 val = canonicalize_type_argument (val, complain);
6558 }
6559 else
6560 {
6561 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6562
6563 if (invalid_nontype_parm_type_p (t, complain))
6564 return error_mark_node;
6565
6566 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6567 {
6568 if (same_type_p (t, TREE_TYPE (orig_arg)))
6569 val = orig_arg;
6570 else
6571 {
6572 /* Not sure if this is reachable, but it doesn't hurt
6573 to be robust. */
6574 error ("type mismatch in nontype parameter pack");
6575 val = error_mark_node;
6576 }
6577 }
6578 else if (!dependent_template_arg_p (orig_arg)
6579 && !uses_template_parms (t))
6580 /* We used to call digest_init here. However, digest_init
6581 will report errors, which we don't want when complain
6582 is zero. More importantly, digest_init will try too
6583 hard to convert things: for example, `0' should not be
6584 converted to pointer type at this point according to
6585 the standard. Accepting this is not merely an
6586 extension, since deciding whether or not these
6587 conversions can occur is part of determining which
6588 function template to call, or whether a given explicit
6589 argument specification is valid. */
6590 val = convert_nontype_argument (t, orig_arg, complain);
6591 else
6592 val = strip_typedefs_expr (orig_arg);
6593
6594 if (val == NULL_TREE)
6595 val = error_mark_node;
6596 else if (val == error_mark_node && (complain & tf_error))
6597 error ("could not convert template argument %qE to %qT", orig_arg, t);
6598
6599 if (TREE_CODE (val) == SCOPE_REF)
6600 {
6601 /* Strip typedefs from the SCOPE_REF. */
6602 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6603 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6604 complain);
6605 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6606 QUALIFIED_NAME_IS_TEMPLATE (val));
6607 }
6608 }
6609
6610 return val;
6611 }
6612
6613 /* Coerces the remaining template arguments in INNER_ARGS (from
6614 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6615 Returns the coerced argument pack. PARM_IDX is the position of this
6616 parameter in the template parameter list. ARGS is the original
6617 template argument list. */
6618 static tree
coerce_template_parameter_pack(tree parms,int parm_idx,tree args,tree inner_args,int arg_idx,tree new_args,int * lost,tree in_decl,tsubst_flags_t complain)6619 coerce_template_parameter_pack (tree parms,
6620 int parm_idx,
6621 tree args,
6622 tree inner_args,
6623 int arg_idx,
6624 tree new_args,
6625 int* lost,
6626 tree in_decl,
6627 tsubst_flags_t complain)
6628 {
6629 tree parm = TREE_VEC_ELT (parms, parm_idx);
6630 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6631 tree packed_args;
6632 tree argument_pack;
6633 tree packed_parms = NULL_TREE;
6634
6635 if (arg_idx > nargs)
6636 arg_idx = nargs;
6637
6638 if (tree packs = fixed_parameter_pack_p (TREE_VALUE (parm)))
6639 {
6640 /* When the template parameter is a non-type template parameter pack
6641 or template template parameter pack whose type or template
6642 parameters use parameter packs, we know exactly how many arguments
6643 we are looking for. Build a vector of the instantiated decls for
6644 these template parameters in PACKED_PARMS. */
6645 /* We can't use make_pack_expansion here because it would interpret a
6646 _DECL as a use rather than a declaration. */
6647 tree decl = TREE_VALUE (parm);
6648 tree exp = cxx_make_type (TYPE_PACK_EXPANSION);
6649 SET_PACK_EXPANSION_PATTERN (exp, decl);
6650 PACK_EXPANSION_PARAMETER_PACKS (exp) = packs;
6651 SET_TYPE_STRUCTURAL_EQUALITY (exp);
6652
6653 TREE_VEC_LENGTH (args)--;
6654 packed_parms = tsubst_pack_expansion (exp, args, complain, decl);
6655 TREE_VEC_LENGTH (args)++;
6656
6657 if (packed_parms == error_mark_node)
6658 return error_mark_node;
6659
6660 /* If we're doing a partial instantiation of a member template,
6661 verify that all of the types used for the non-type
6662 template parameter pack are, in fact, valid for non-type
6663 template parameters. */
6664 if (arg_idx < nargs
6665 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6666 {
6667 int j, len = TREE_VEC_LENGTH (packed_parms);
6668 for (j = 0; j < len; ++j)
6669 {
6670 tree t = TREE_TYPE (TREE_VEC_ELT (packed_parms, j));
6671 if (invalid_nontype_parm_type_p (t, complain))
6672 return error_mark_node;
6673 }
6674 }
6675
6676 packed_args = make_tree_vec (TREE_VEC_LENGTH (packed_parms));
6677 }
6678 else
6679 packed_args = make_tree_vec (nargs - arg_idx);
6680
6681 /* Convert the remaining arguments, which will be a part of the
6682 parameter pack "parm". */
6683 for (; arg_idx < nargs; ++arg_idx)
6684 {
6685 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6686 tree actual_parm = TREE_VALUE (parm);
6687 int pack_idx = arg_idx - parm_idx;
6688
6689 if (packed_parms)
6690 {
6691 /* Once we've packed as many args as we have types, stop. */
6692 if (pack_idx >= TREE_VEC_LENGTH (packed_parms))
6693 break;
6694 else if (PACK_EXPANSION_P (arg))
6695 /* We don't know how many args we have yet, just
6696 use the unconverted ones for now. */
6697 return NULL_TREE;
6698 else
6699 actual_parm = TREE_VEC_ELT (packed_parms, pack_idx);
6700 }
6701
6702 if (arg == error_mark_node)
6703 {
6704 if (complain & tf_error)
6705 error ("template argument %d is invalid", arg_idx + 1);
6706 }
6707 else
6708 arg = convert_template_argument (actual_parm,
6709 arg, new_args, complain, parm_idx,
6710 in_decl);
6711 if (arg == error_mark_node)
6712 (*lost)++;
6713 TREE_VEC_ELT (packed_args, pack_idx) = arg;
6714 }
6715
6716 if (arg_idx - parm_idx < TREE_VEC_LENGTH (packed_args)
6717 && TREE_VEC_LENGTH (packed_args) > 0)
6718 {
6719 error ("wrong number of template arguments (%d, should be %d)",
6720 arg_idx - parm_idx, TREE_VEC_LENGTH (packed_args));
6721 return error_mark_node;
6722 }
6723
6724 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6725 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6726 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6727 else
6728 {
6729 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6730 TREE_TYPE (argument_pack)
6731 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6732 TREE_CONSTANT (argument_pack) = 1;
6733 }
6734
6735 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6736 #ifdef ENABLE_CHECKING
6737 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6738 TREE_VEC_LENGTH (packed_args));
6739 #endif
6740 return argument_pack;
6741 }
6742
6743 /* Returns the number of pack expansions in the template argument vector
6744 ARGS. */
6745
6746 static int
pack_expansion_args_count(tree args)6747 pack_expansion_args_count (tree args)
6748 {
6749 int i;
6750 int count = 0;
6751 if (args)
6752 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
6753 {
6754 tree elt = TREE_VEC_ELT (args, i);
6755 if (elt && PACK_EXPANSION_P (elt))
6756 ++count;
6757 }
6758 return count;
6759 }
6760
6761 /* Convert all template arguments to their appropriate types, and
6762 return a vector containing the innermost resulting template
6763 arguments. If any error occurs, return error_mark_node. Error and
6764 warning messages are issued under control of COMPLAIN.
6765
6766 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6767 for arguments not specified in ARGS. Otherwise, if
6768 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6769 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6770 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6771 ARGS. */
6772
6773 static tree
coerce_template_parms(tree parms,tree args,tree in_decl,tsubst_flags_t complain,bool require_all_args,bool use_default_args)6774 coerce_template_parms (tree parms,
6775 tree args,
6776 tree in_decl,
6777 tsubst_flags_t complain,
6778 bool require_all_args,
6779 bool use_default_args)
6780 {
6781 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6782 tree orig_inner_args;
6783 tree inner_args;
6784 tree new_args;
6785 tree new_inner_args;
6786 int saved_unevaluated_operand;
6787 int saved_inhibit_evaluation_warnings;
6788
6789 /* When used as a boolean value, indicates whether this is a
6790 variadic template parameter list. Since it's an int, we can also
6791 subtract it from nparms to get the number of non-variadic
6792 parameters. */
6793 int variadic_p = 0;
6794 int variadic_args_p = 0;
6795 int post_variadic_parms = 0;
6796
6797 if (args == error_mark_node)
6798 return error_mark_node;
6799
6800 nparms = TREE_VEC_LENGTH (parms);
6801
6802 /* Determine if there are any parameter packs. */
6803 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6804 {
6805 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6806 if (variadic_p)
6807 ++post_variadic_parms;
6808 if (template_parameter_pack_p (tparm))
6809 ++variadic_p;
6810 }
6811
6812 inner_args = orig_inner_args = INNERMOST_TEMPLATE_ARGS (args);
6813 /* If there are no parameters that follow a parameter pack, we need to
6814 expand any argument packs so that we can deduce a parameter pack from
6815 some non-packed args followed by an argument pack, as in variadic85.C.
6816 If there are such parameters, we need to leave argument packs intact
6817 so the arguments are assigned properly. This can happen when dealing
6818 with a nested class inside a partial specialization of a class
6819 template, as in variadic92.C, or when deducing a template parameter pack
6820 from a sub-declarator, as in variadic114.C. */
6821 if (!post_variadic_parms)
6822 inner_args = expand_template_argument_pack (inner_args);
6823
6824 /* Count any pack expansion args. */
6825 variadic_args_p = pack_expansion_args_count (inner_args);
6826
6827 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6828 if ((nargs > nparms && !variadic_p)
6829 || (nargs < nparms - variadic_p
6830 && require_all_args
6831 && !variadic_args_p
6832 && (!use_default_args
6833 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6834 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6835 {
6836 if (complain & tf_error)
6837 {
6838 if (variadic_p)
6839 {
6840 nparms -= variadic_p;
6841 error ("wrong number of template arguments "
6842 "(%d, should be %d or more)", nargs, nparms);
6843 }
6844 else
6845 error ("wrong number of template arguments "
6846 "(%d, should be %d)", nargs, nparms);
6847
6848 if (in_decl)
6849 error ("provided for %q+D", in_decl);
6850 }
6851
6852 return error_mark_node;
6853 }
6854 /* We can't pass a pack expansion to a non-pack parameter of an alias
6855 template (DR 1430). */
6856 else if (in_decl && DECL_ALIAS_TEMPLATE_P (in_decl)
6857 && variadic_args_p
6858 && nargs - variadic_args_p < nparms - variadic_p)
6859 {
6860 if (complain & tf_error)
6861 {
6862 for (int i = 0; i < TREE_VEC_LENGTH (inner_args); ++i)
6863 {
6864 tree arg = TREE_VEC_ELT (inner_args, i);
6865 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
6866
6867 if (PACK_EXPANSION_P (arg)
6868 && !template_parameter_pack_p (parm))
6869 {
6870 error ("pack expansion argument for non-pack parameter "
6871 "%qD of alias template %qD", parm, in_decl);
6872 inform (DECL_SOURCE_LOCATION (parm), "declared here");
6873 goto found;
6874 }
6875 }
6876 gcc_unreachable ();
6877 found:;
6878 }
6879 return error_mark_node;
6880 }
6881
6882 /* We need to evaluate the template arguments, even though this
6883 template-id may be nested within a "sizeof". */
6884 saved_unevaluated_operand = cp_unevaluated_operand;
6885 cp_unevaluated_operand = 0;
6886 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6887 c_inhibit_evaluation_warnings = 0;
6888 new_inner_args = make_tree_vec (nparms);
6889 new_args = add_outermost_template_args (args, new_inner_args);
6890 int pack_adjust = 0;
6891 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6892 {
6893 tree arg;
6894 tree parm;
6895
6896 /* Get the Ith template parameter. */
6897 parm = TREE_VEC_ELT (parms, parm_idx);
6898
6899 if (parm == error_mark_node)
6900 {
6901 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6902 continue;
6903 }
6904
6905 /* Calculate the next argument. */
6906 if (arg_idx < nargs)
6907 arg = TREE_VEC_ELT (inner_args, arg_idx);
6908 else
6909 arg = NULL_TREE;
6910
6911 if (template_parameter_pack_p (TREE_VALUE (parm))
6912 && !(arg && ARGUMENT_PACK_P (arg)))
6913 {
6914 /* Some arguments will be placed in the
6915 template parameter pack PARM. */
6916 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6917 inner_args, arg_idx,
6918 new_args, &lost,
6919 in_decl, complain);
6920
6921 if (arg == NULL_TREE)
6922 {
6923 /* We don't know how many args we have yet, just use the
6924 unconverted (and still packed) ones for now. */
6925 new_inner_args = orig_inner_args;
6926 arg_idx = nargs;
6927 break;
6928 }
6929
6930 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6931
6932 /* Store this argument. */
6933 if (arg == error_mark_node)
6934 {
6935 lost++;
6936 /* We are done with all of the arguments. */
6937 arg_idx = nargs;
6938 }
6939 else
6940 {
6941 pack_adjust = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)) - 1;
6942 arg_idx += pack_adjust;
6943 }
6944
6945 continue;
6946 }
6947 else if (arg)
6948 {
6949 if (PACK_EXPANSION_P (arg))
6950 {
6951 /* "If every valid specialization of a variadic template
6952 requires an empty template parameter pack, the template is
6953 ill-formed, no diagnostic required." So check that the
6954 pattern works with this parameter. */
6955 tree pattern = PACK_EXPANSION_PATTERN (arg);
6956 tree conv = convert_template_argument (TREE_VALUE (parm),
6957 pattern, new_args,
6958 complain, parm_idx,
6959 in_decl);
6960 if (conv == error_mark_node)
6961 {
6962 inform (input_location, "so any instantiation with a "
6963 "non-empty parameter pack would be ill-formed");
6964 ++lost;
6965 }
6966 else if (TYPE_P (conv) && !TYPE_P (pattern))
6967 /* Recover from missing typename. */
6968 TREE_VEC_ELT (inner_args, arg_idx)
6969 = make_pack_expansion (conv);
6970
6971 /* We don't know how many args we have yet, just
6972 use the unconverted ones for now. */
6973 new_inner_args = inner_args;
6974 arg_idx = nargs;
6975 break;
6976 }
6977 }
6978 else if (require_all_args)
6979 {
6980 /* There must be a default arg in this case. */
6981 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6982 complain, in_decl);
6983 /* The position of the first default template argument,
6984 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6985 Record that. */
6986 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6987 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6988 arg_idx - pack_adjust);
6989 }
6990 else
6991 break;
6992
6993 if (arg == error_mark_node)
6994 {
6995 if (complain & tf_error)
6996 error ("template argument %d is invalid", arg_idx + 1);
6997 }
6998 else if (!arg)
6999 /* This only occurs if there was an error in the template
7000 parameter list itself (which we would already have
7001 reported) that we are trying to recover from, e.g., a class
7002 template with a parameter list such as
7003 template<typename..., typename>. */
7004 ++lost;
7005 else
7006 arg = convert_template_argument (TREE_VALUE (parm),
7007 arg, new_args, complain,
7008 parm_idx, in_decl);
7009
7010 if (arg == error_mark_node)
7011 lost++;
7012 TREE_VEC_ELT (new_inner_args, arg_idx - pack_adjust) = arg;
7013 }
7014 cp_unevaluated_operand = saved_unevaluated_operand;
7015 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
7016
7017 if (variadic_p && arg_idx < nargs)
7018 {
7019 if (complain & tf_error)
7020 {
7021 error ("wrong number of template arguments "
7022 "(%d, should be %d)", nargs, arg_idx);
7023 if (in_decl)
7024 error ("provided for %q+D", in_decl);
7025 }
7026 return error_mark_node;
7027 }
7028
7029 if (lost)
7030 return error_mark_node;
7031
7032 #ifdef ENABLE_CHECKING
7033 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
7034 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
7035 TREE_VEC_LENGTH (new_inner_args));
7036 #endif
7037
7038 return new_inner_args;
7039 }
7040
7041 /* Like coerce_template_parms. If PARMS represents all template
7042 parameters levels, this function returns a vector of vectors
7043 representing all the resulting argument levels. Note that in this
7044 case, only the innermost arguments are coerced because the
7045 outermost ones are supposed to have been coerced already.
7046
7047 Otherwise, if PARMS represents only (the innermost) vector of
7048 parameters, this function returns a vector containing just the
7049 innermost resulting arguments. */
7050
7051 static tree
coerce_innermost_template_parms(tree parms,tree args,tree in_decl,tsubst_flags_t complain,bool require_all_args,bool use_default_args)7052 coerce_innermost_template_parms (tree parms,
7053 tree args,
7054 tree in_decl,
7055 tsubst_flags_t complain,
7056 bool require_all_args,
7057 bool use_default_args)
7058 {
7059 int parms_depth = TMPL_PARMS_DEPTH (parms);
7060 int args_depth = TMPL_ARGS_DEPTH (args);
7061 tree coerced_args;
7062
7063 if (parms_depth > 1)
7064 {
7065 coerced_args = make_tree_vec (parms_depth);
7066 tree level;
7067 int cur_depth;
7068
7069 for (level = parms, cur_depth = parms_depth;
7070 parms_depth > 0 && level != NULL_TREE;
7071 level = TREE_CHAIN (level), --cur_depth)
7072 {
7073 tree l;
7074 if (cur_depth == args_depth)
7075 l = coerce_template_parms (TREE_VALUE (level),
7076 args, in_decl, complain,
7077 require_all_args,
7078 use_default_args);
7079 else
7080 l = TMPL_ARGS_LEVEL (args, cur_depth);
7081
7082 if (l == error_mark_node)
7083 return error_mark_node;
7084
7085 SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
7086 }
7087 }
7088 else
7089 coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
7090 args, in_decl, complain,
7091 require_all_args,
7092 use_default_args);
7093 return coerced_args;
7094 }
7095
7096 /* Returns 1 if template args OT and NT are equivalent. */
7097
7098 static int
template_args_equal(tree ot,tree nt)7099 template_args_equal (tree ot, tree nt)
7100 {
7101 if (nt == ot)
7102 return 1;
7103 if (nt == NULL_TREE || ot == NULL_TREE)
7104 return false;
7105
7106 if (TREE_CODE (nt) == TREE_VEC)
7107 /* For member templates */
7108 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
7109 else if (PACK_EXPANSION_P (ot))
7110 return (PACK_EXPANSION_P (nt)
7111 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
7112 PACK_EXPANSION_PATTERN (nt))
7113 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
7114 PACK_EXPANSION_EXTRA_ARGS (nt)));
7115 else if (ARGUMENT_PACK_P (ot))
7116 {
7117 int i, len;
7118 tree opack, npack;
7119
7120 if (!ARGUMENT_PACK_P (nt))
7121 return 0;
7122
7123 opack = ARGUMENT_PACK_ARGS (ot);
7124 npack = ARGUMENT_PACK_ARGS (nt);
7125 len = TREE_VEC_LENGTH (opack);
7126 if (TREE_VEC_LENGTH (npack) != len)
7127 return 0;
7128 for (i = 0; i < len; ++i)
7129 if (!template_args_equal (TREE_VEC_ELT (opack, i),
7130 TREE_VEC_ELT (npack, i)))
7131 return 0;
7132 return 1;
7133 }
7134 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
7135 {
7136 /* We get here probably because we are in the middle of substituting
7137 into the pattern of a pack expansion. In that case the
7138 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7139 interested in. So we want to use the initial pack argument for
7140 the comparison. */
7141 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
7142 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
7143 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
7144 return template_args_equal (ot, nt);
7145 }
7146 else if (TYPE_P (nt))
7147 return TYPE_P (ot) && same_type_p (ot, nt);
7148 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
7149 return 0;
7150 else
7151 return cp_tree_equal (ot, nt);
7152 }
7153
7154 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7155 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7156 NEWARG_PTR with the offending arguments if they are non-NULL. */
7157
7158 static int
comp_template_args_with_info(tree oldargs,tree newargs,tree * oldarg_ptr,tree * newarg_ptr)7159 comp_template_args_with_info (tree oldargs, tree newargs,
7160 tree *oldarg_ptr, tree *newarg_ptr)
7161 {
7162 int i;
7163
7164 if (oldargs == newargs)
7165 return 1;
7166
7167 if (!oldargs || !newargs)
7168 return 0;
7169
7170 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7171 return 0;
7172
7173 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7174 {
7175 tree nt = TREE_VEC_ELT (newargs, i);
7176 tree ot = TREE_VEC_ELT (oldargs, i);
7177
7178 if (! template_args_equal (ot, nt))
7179 {
7180 if (oldarg_ptr != NULL)
7181 *oldarg_ptr = ot;
7182 if (newarg_ptr != NULL)
7183 *newarg_ptr = nt;
7184 return 0;
7185 }
7186 }
7187 return 1;
7188 }
7189
7190 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7191 of template arguments. Returns 0 otherwise. */
7192
7193 int
comp_template_args(tree oldargs,tree newargs)7194 comp_template_args (tree oldargs, tree newargs)
7195 {
7196 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
7197 }
7198
7199 static void
add_pending_template(tree d)7200 add_pending_template (tree d)
7201 {
7202 tree ti = (TYPE_P (d)
7203 ? CLASSTYPE_TEMPLATE_INFO (d)
7204 : DECL_TEMPLATE_INFO (d));
7205 struct pending_template *pt;
7206 int level;
7207
7208 if (TI_PENDING_TEMPLATE_FLAG (ti))
7209 return;
7210
7211 /* We are called both from instantiate_decl, where we've already had a
7212 tinst_level pushed, and instantiate_template, where we haven't.
7213 Compensate. */
7214 level = !current_tinst_level || current_tinst_level->decl != d;
7215
7216 if (level)
7217 push_tinst_level (d);
7218
7219 pt = ggc_alloc_pending_template ();
7220 pt->next = NULL;
7221 pt->tinst = current_tinst_level;
7222 if (last_pending_template)
7223 last_pending_template->next = pt;
7224 else
7225 pending_templates = pt;
7226
7227 last_pending_template = pt;
7228
7229 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7230
7231 if (level)
7232 pop_tinst_level ();
7233 }
7234
7235
7236 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7237 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7238 documentation for TEMPLATE_ID_EXPR. */
7239
7240 tree
lookup_template_function(tree fns,tree arglist)7241 lookup_template_function (tree fns, tree arglist)
7242 {
7243 tree type;
7244
7245 if (fns == error_mark_node || arglist == error_mark_node)
7246 return error_mark_node;
7247
7248 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7249
7250 if (!is_overloaded_fn (fns) && !identifier_p (fns))
7251 {
7252 error ("%q#D is not a function template", fns);
7253 return error_mark_node;
7254 }
7255
7256 if (BASELINK_P (fns))
7257 {
7258 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7259 unknown_type_node,
7260 BASELINK_FUNCTIONS (fns),
7261 arglist);
7262 return fns;
7263 }
7264
7265 type = TREE_TYPE (fns);
7266 if (TREE_CODE (fns) == OVERLOAD || !type)
7267 type = unknown_type_node;
7268
7269 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7270 }
7271
7272 /* Within the scope of a template class S<T>, the name S gets bound
7273 (in build_self_reference) to a TYPE_DECL for the class, not a
7274 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7275 or one of its enclosing classes, and that type is a template,
7276 return the associated TEMPLATE_DECL. Otherwise, the original
7277 DECL is returned.
7278
7279 Also handle the case when DECL is a TREE_LIST of ambiguous
7280 injected-class-names from different bases. */
7281
7282 tree
maybe_get_template_decl_from_type_decl(tree decl)7283 maybe_get_template_decl_from_type_decl (tree decl)
7284 {
7285 if (decl == NULL_TREE)
7286 return decl;
7287
7288 /* DR 176: A lookup that finds an injected-class-name (10.2
7289 [class.member.lookup]) can result in an ambiguity in certain cases
7290 (for example, if it is found in more than one base class). If all of
7291 the injected-class-names that are found refer to specializations of
7292 the same class template, and if the name is followed by a
7293 template-argument-list, the reference refers to the class template
7294 itself and not a specialization thereof, and is not ambiguous. */
7295 if (TREE_CODE (decl) == TREE_LIST)
7296 {
7297 tree t, tmpl = NULL_TREE;
7298 for (t = decl; t; t = TREE_CHAIN (t))
7299 {
7300 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7301 if (!tmpl)
7302 tmpl = elt;
7303 else if (tmpl != elt)
7304 break;
7305 }
7306 if (tmpl && t == NULL_TREE)
7307 return tmpl;
7308 else
7309 return decl;
7310 }
7311
7312 return (decl != NULL_TREE
7313 && DECL_SELF_REFERENCE_P (decl)
7314 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7315 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7316 }
7317
7318 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
7319 parameters, find the desired type.
7320
7321 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7322
7323 IN_DECL, if non-NULL, is the template declaration we are trying to
7324 instantiate.
7325
7326 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7327 the class we are looking up.
7328
7329 Issue error and warning messages under control of COMPLAIN.
7330
7331 If the template class is really a local class in a template
7332 function, then the FUNCTION_CONTEXT is the function in which it is
7333 being instantiated.
7334
7335 ??? Note that this function is currently called *twice* for each
7336 template-id: the first time from the parser, while creating the
7337 incomplete type (finish_template_type), and the second type during the
7338 real instantiation (instantiate_template_class). This is surely something
7339 that we want to avoid. It also causes some problems with argument
7340 coercion (see convert_nontype_argument for more information on this). */
7341
7342 static tree
lookup_template_class_1(tree d1,tree arglist,tree in_decl,tree context,int entering_scope,tsubst_flags_t complain)7343 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7344 int entering_scope, tsubst_flags_t complain)
7345 {
7346 tree templ = NULL_TREE, parmlist;
7347 tree t;
7348 void **slot;
7349 spec_entry *entry;
7350 spec_entry elt;
7351 hashval_t hash;
7352
7353 if (identifier_p (d1))
7354 {
7355 tree value = innermost_non_namespace_value (d1);
7356 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7357 templ = value;
7358 else
7359 {
7360 if (context)
7361 push_decl_namespace (context);
7362 templ = lookup_name (d1);
7363 templ = maybe_get_template_decl_from_type_decl (templ);
7364 if (context)
7365 pop_decl_namespace ();
7366 }
7367 if (templ)
7368 context = DECL_CONTEXT (templ);
7369 }
7370 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7371 {
7372 tree type = TREE_TYPE (d1);
7373
7374 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7375 an implicit typename for the second A. Deal with it. */
7376 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7377 type = TREE_TYPE (type);
7378
7379 if (CLASSTYPE_TEMPLATE_INFO (type))
7380 {
7381 templ = CLASSTYPE_TI_TEMPLATE (type);
7382 d1 = DECL_NAME (templ);
7383 }
7384 }
7385 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7386 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7387 {
7388 templ = TYPE_TI_TEMPLATE (d1);
7389 d1 = DECL_NAME (templ);
7390 }
7391 else if (TREE_CODE (d1) == TEMPLATE_DECL
7392 && DECL_TEMPLATE_RESULT (d1)
7393 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7394 {
7395 templ = d1;
7396 d1 = DECL_NAME (templ);
7397 context = DECL_CONTEXT (templ);
7398 }
7399 else if (DECL_TEMPLATE_TEMPLATE_PARM_P (d1))
7400 {
7401 templ = d1;
7402 d1 = DECL_NAME (templ);
7403 }
7404
7405 /* Issue an error message if we didn't find a template. */
7406 if (! templ)
7407 {
7408 if (complain & tf_error)
7409 error ("%qT is not a template", d1);
7410 return error_mark_node;
7411 }
7412
7413 if (TREE_CODE (templ) != TEMPLATE_DECL
7414 /* Make sure it's a user visible template, if it was named by
7415 the user. */
7416 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7417 && !PRIMARY_TEMPLATE_P (templ)))
7418 {
7419 if (complain & tf_error)
7420 {
7421 error ("non-template type %qT used as a template", d1);
7422 if (in_decl)
7423 error ("for template declaration %q+D", in_decl);
7424 }
7425 return error_mark_node;
7426 }
7427
7428 complain &= ~tf_user;
7429
7430 /* An alias that just changes the name of a template is equivalent to the
7431 other template, so if any of the arguments are pack expansions, strip
7432 the alias to avoid problems with a pack expansion passed to a non-pack
7433 alias template parameter (DR 1430). */
7434 if (pack_expansion_args_count (INNERMOST_TEMPLATE_ARGS (arglist)))
7435 templ = get_underlying_template (templ);
7436
7437 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7438 {
7439 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7440 template arguments */
7441
7442 tree parm;
7443 tree arglist2;
7444 tree outer;
7445
7446 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7447
7448 /* Consider an example where a template template parameter declared as
7449
7450 template <class T, class U = std::allocator<T> > class TT
7451
7452 The template parameter level of T and U are one level larger than
7453 of TT. To proper process the default argument of U, say when an
7454 instantiation `TT<int>' is seen, we need to build the full
7455 arguments containing {int} as the innermost level. Outer levels,
7456 available when not appearing as default template argument, can be
7457 obtained from the arguments of the enclosing template.
7458
7459 Suppose that TT is later substituted with std::vector. The above
7460 instantiation is `TT<int, std::allocator<T> >' with TT at
7461 level 1, and T at level 2, while the template arguments at level 1
7462 becomes {std::vector} and the inner level 2 is {int}. */
7463
7464 outer = DECL_CONTEXT (templ);
7465 if (outer)
7466 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7467 else if (current_template_parms)
7468 /* This is an argument of the current template, so we haven't set
7469 DECL_CONTEXT yet. */
7470 outer = current_template_args ();
7471
7472 if (outer)
7473 arglist = add_to_template_args (outer, arglist);
7474
7475 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7476 complain,
7477 /*require_all_args=*/true,
7478 /*use_default_args=*/true);
7479 if (arglist2 == error_mark_node
7480 || (!uses_template_parms (arglist2)
7481 && check_instantiated_args (templ, arglist2, complain)))
7482 return error_mark_node;
7483
7484 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7485 return parm;
7486 }
7487 else
7488 {
7489 tree template_type = TREE_TYPE (templ);
7490 tree gen_tmpl;
7491 tree type_decl;
7492 tree found = NULL_TREE;
7493 int arg_depth;
7494 int parm_depth;
7495 int is_dependent_type;
7496 int use_partial_inst_tmpl = false;
7497
7498 if (template_type == error_mark_node)
7499 /* An error occurred while building the template TEMPL, and a
7500 diagnostic has most certainly been emitted for that
7501 already. Let's propagate that error. */
7502 return error_mark_node;
7503
7504 gen_tmpl = most_general_template (templ);
7505 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7506 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7507 arg_depth = TMPL_ARGS_DEPTH (arglist);
7508
7509 if (arg_depth == 1 && parm_depth > 1)
7510 {
7511 /* We've been given an incomplete set of template arguments.
7512 For example, given:
7513
7514 template <class T> struct S1 {
7515 template <class U> struct S2 {};
7516 template <class U> struct S2<U*> {};
7517 };
7518
7519 we will be called with an ARGLIST of `U*', but the
7520 TEMPLATE will be `template <class T> template
7521 <class U> struct S1<T>::S2'. We must fill in the missing
7522 arguments. */
7523 arglist
7524 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7525 arglist);
7526 arg_depth = TMPL_ARGS_DEPTH (arglist);
7527 }
7528
7529 /* Now we should have enough arguments. */
7530 gcc_assert (parm_depth == arg_depth);
7531
7532 /* From here on, we're only interested in the most general
7533 template. */
7534
7535 /* Calculate the BOUND_ARGS. These will be the args that are
7536 actually tsubst'd into the definition to create the
7537 instantiation. */
7538 if (parm_depth > 1)
7539 {
7540 /* We have multiple levels of arguments to coerce, at once. */
7541 int i;
7542 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7543
7544 tree bound_args = make_tree_vec (parm_depth);
7545
7546 for (i = saved_depth,
7547 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7548 i > 0 && t != NULL_TREE;
7549 --i, t = TREE_CHAIN (t))
7550 {
7551 tree a;
7552 if (i == saved_depth)
7553 a = coerce_template_parms (TREE_VALUE (t),
7554 arglist, gen_tmpl,
7555 complain,
7556 /*require_all_args=*/true,
7557 /*use_default_args=*/true);
7558 else
7559 /* Outer levels should have already been coerced. */
7560 a = TMPL_ARGS_LEVEL (arglist, i);
7561
7562 /* Don't process further if one of the levels fails. */
7563 if (a == error_mark_node)
7564 {
7565 /* Restore the ARGLIST to its full size. */
7566 TREE_VEC_LENGTH (arglist) = saved_depth;
7567 return error_mark_node;
7568 }
7569
7570 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7571
7572 /* We temporarily reduce the length of the ARGLIST so
7573 that coerce_template_parms will see only the arguments
7574 corresponding to the template parameters it is
7575 examining. */
7576 TREE_VEC_LENGTH (arglist)--;
7577 }
7578
7579 /* Restore the ARGLIST to its full size. */
7580 TREE_VEC_LENGTH (arglist) = saved_depth;
7581
7582 arglist = bound_args;
7583 }
7584 else
7585 arglist
7586 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7587 INNERMOST_TEMPLATE_ARGS (arglist),
7588 gen_tmpl,
7589 complain,
7590 /*require_all_args=*/true,
7591 /*use_default_args=*/true);
7592
7593 if (arglist == error_mark_node)
7594 /* We were unable to bind the arguments. */
7595 return error_mark_node;
7596
7597 /* In the scope of a template class, explicit references to the
7598 template class refer to the type of the template, not any
7599 instantiation of it. For example, in:
7600
7601 template <class T> class C { void f(C<T>); }
7602
7603 the `C<T>' is just the same as `C'. Outside of the
7604 class, however, such a reference is an instantiation. */
7605 if ((entering_scope
7606 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7607 || currently_open_class (template_type))
7608 /* comp_template_args is expensive, check it last. */
7609 && comp_template_args (TYPE_TI_ARGS (template_type),
7610 arglist))
7611 return template_type;
7612
7613 /* If we already have this specialization, return it. */
7614 elt.tmpl = gen_tmpl;
7615 elt.args = arglist;
7616 hash = hash_specialization (&elt);
7617 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7618 &elt, hash);
7619
7620 if (entry)
7621 return entry->spec;
7622
7623 is_dependent_type = uses_template_parms (arglist);
7624
7625 /* If the deduced arguments are invalid, then the binding
7626 failed. */
7627 if (!is_dependent_type
7628 && check_instantiated_args (gen_tmpl,
7629 INNERMOST_TEMPLATE_ARGS (arglist),
7630 complain))
7631 return error_mark_node;
7632
7633 if (!is_dependent_type
7634 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7635 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7636 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7637 {
7638 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7639 DECL_NAME (gen_tmpl),
7640 /*tag_scope=*/ts_global);
7641 return found;
7642 }
7643
7644 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7645 complain, in_decl);
7646 if (context == error_mark_node)
7647 return error_mark_node;
7648
7649 if (!context)
7650 context = global_namespace;
7651
7652 /* Create the type. */
7653 if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7654 {
7655 /* The user referred to a specialization of an alias
7656 template represented by GEN_TMPL.
7657
7658 [temp.alias]/2 says:
7659
7660 When a template-id refers to the specialization of an
7661 alias template, it is equivalent to the associated
7662 type obtained by substitution of its
7663 template-arguments for the template-parameters in the
7664 type-id of the alias template. */
7665
7666 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7667 /* Note that the call above (by indirectly calling
7668 register_specialization in tsubst_decl) registers the
7669 TYPE_DECL representing the specialization of the alias
7670 template. So next time someone substitutes ARGLIST for
7671 the template parms into the alias template (GEN_TMPL),
7672 she'll get that TYPE_DECL back. */
7673
7674 if (t == error_mark_node)
7675 return t;
7676 }
7677 else if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7678 {
7679 if (!is_dependent_type)
7680 {
7681 set_current_access_from_decl (TYPE_NAME (template_type));
7682 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7683 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7684 arglist, complain, in_decl),
7685 SCOPED_ENUM_P (template_type), NULL);
7686
7687 if (t == error_mark_node)
7688 return t;
7689 }
7690 else
7691 {
7692 /* We don't want to call start_enum for this type, since
7693 the values for the enumeration constants may involve
7694 template parameters. And, no one should be interested
7695 in the enumeration constants for such a type. */
7696 t = cxx_make_type (ENUMERAL_TYPE);
7697 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7698 }
7699 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7700 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7701 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7702 }
7703 else if (CLASS_TYPE_P (template_type))
7704 {
7705 t = make_class_type (TREE_CODE (template_type));
7706 CLASSTYPE_DECLARED_CLASS (t)
7707 = CLASSTYPE_DECLARED_CLASS (template_type);
7708 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7709 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7710
7711 /* A local class. Make sure the decl gets registered properly. */
7712 if (context == current_function_decl)
7713 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7714
7715 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7716 /* This instantiation is another name for the primary
7717 template type. Set the TYPE_CANONICAL field
7718 appropriately. */
7719 TYPE_CANONICAL (t) = template_type;
7720 else if (any_template_arguments_need_structural_equality_p (arglist))
7721 /* Some of the template arguments require structural
7722 equality testing, so this template class requires
7723 structural equality testing. */
7724 SET_TYPE_STRUCTURAL_EQUALITY (t);
7725 }
7726 else
7727 gcc_unreachable ();
7728
7729 /* If we called start_enum or pushtag above, this information
7730 will already be set up. */
7731 if (!TYPE_NAME (t))
7732 {
7733 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7734
7735 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7736 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7737 DECL_SOURCE_LOCATION (type_decl)
7738 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7739 }
7740 else
7741 type_decl = TYPE_NAME (t);
7742
7743 if (CLASS_TYPE_P (template_type))
7744 {
7745 TREE_PRIVATE (type_decl)
7746 = TREE_PRIVATE (TYPE_MAIN_DECL (template_type));
7747 TREE_PROTECTED (type_decl)
7748 = TREE_PROTECTED (TYPE_MAIN_DECL (template_type));
7749 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7750 {
7751 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7752 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7753 }
7754 }
7755
7756 /* Let's consider the explicit specialization of a member
7757 of a class template specialization that is implicitly instantiated,
7758 e.g.:
7759 template<class T>
7760 struct S
7761 {
7762 template<class U> struct M {}; //#0
7763 };
7764
7765 template<>
7766 template<>
7767 struct S<int>::M<char> //#1
7768 {
7769 int i;
7770 };
7771 [temp.expl.spec]/4 says this is valid.
7772
7773 In this case, when we write:
7774 S<int>::M<char> m;
7775
7776 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7777 the one of #0.
7778
7779 When we encounter #1, we want to store the partial instantiation
7780 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
7781
7782 For all cases other than this "explicit specialization of member of a
7783 class template", we just want to store the most general template into
7784 the CLASSTYPE_TI_TEMPLATE of M.
7785
7786 This case of "explicit specialization of member of a class template"
7787 only happens when:
7788 1/ the enclosing class is an instantiation of, and therefore not
7789 the same as, the context of the most general template, and
7790 2/ we aren't looking at the partial instantiation itself, i.e.
7791 the innermost arguments are not the same as the innermost parms of
7792 the most general template.
7793
7794 So it's only when 1/ and 2/ happens that we want to use the partial
7795 instantiation of the member template in lieu of its most general
7796 template. */
7797
7798 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7799 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7800 /* the enclosing class must be an instantiation... */
7801 && CLASS_TYPE_P (context)
7802 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7803 {
7804 tree partial_inst_args;
7805 TREE_VEC_LENGTH (arglist)--;
7806 ++processing_template_decl;
7807 partial_inst_args =
7808 tsubst (INNERMOST_TEMPLATE_ARGS
7809 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7810 arglist, complain, NULL_TREE);
7811 --processing_template_decl;
7812 TREE_VEC_LENGTH (arglist)++;
7813 use_partial_inst_tmpl =
7814 /*...and we must not be looking at the partial instantiation
7815 itself. */
7816 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7817 partial_inst_args);
7818 }
7819
7820 if (!use_partial_inst_tmpl)
7821 /* This case is easy; there are no member templates involved. */
7822 found = gen_tmpl;
7823 else
7824 {
7825 /* This is a full instantiation of a member template. Find
7826 the partial instantiation of which this is an instance. */
7827
7828 /* Temporarily reduce by one the number of levels in the ARGLIST
7829 so as to avoid comparing the last set of arguments. */
7830 TREE_VEC_LENGTH (arglist)--;
7831 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7832 TREE_VEC_LENGTH (arglist)++;
7833 /* FOUND is either a proper class type, or an alias
7834 template specialization. In the later case, it's a
7835 TYPE_DECL, resulting from the substituting of arguments
7836 for parameters in the TYPE_DECL of the alias template
7837 done earlier. So be careful while getting the template
7838 of FOUND. */
7839 found = TREE_CODE (found) == TYPE_DECL
7840 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7841 : CLASSTYPE_TI_TEMPLATE (found);
7842 }
7843
7844 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7845
7846 elt.spec = t;
7847 slot = htab_find_slot_with_hash (type_specializations,
7848 &elt, hash, INSERT);
7849 entry = ggc_alloc_spec_entry ();
7850 *entry = elt;
7851 *slot = entry;
7852
7853 /* Note this use of the partial instantiation so we can check it
7854 later in maybe_process_partial_specialization. */
7855 DECL_TEMPLATE_INSTANTIATIONS (found)
7856 = tree_cons (arglist, t,
7857 DECL_TEMPLATE_INSTANTIATIONS (found));
7858
7859 if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type
7860 && !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7861 /* Now that the type has been registered on the instantiations
7862 list, we set up the enumerators. Because the enumeration
7863 constants may involve the enumeration type itself, we make
7864 sure to register the type first, and then create the
7865 constants. That way, doing tsubst_expr for the enumeration
7866 constants won't result in recursive calls here; we'll find
7867 the instantiation and exit above. */
7868 tsubst_enum (template_type, t, arglist);
7869
7870 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7871 /* If the type makes use of template parameters, the
7872 code that generates debugging information will crash. */
7873 DECL_IGNORED_P (TYPE_MAIN_DECL (t)) = 1;
7874
7875 /* Possibly limit visibility based on template args. */
7876 TREE_PUBLIC (type_decl) = 1;
7877 determine_visibility (type_decl);
7878
7879 return t;
7880 }
7881 }
7882
7883 /* Wrapper for lookup_template_class_1. */
7884
7885 tree
lookup_template_class(tree d1,tree arglist,tree in_decl,tree context,int entering_scope,tsubst_flags_t complain)7886 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7887 int entering_scope, tsubst_flags_t complain)
7888 {
7889 tree ret;
7890 timevar_push (TV_TEMPLATE_INST);
7891 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7892 entering_scope, complain);
7893 timevar_pop (TV_TEMPLATE_INST);
7894 return ret;
7895 }
7896
7897 struct pair_fn_data
7898 {
7899 tree_fn_t fn;
7900 void *data;
7901 /* True when we should also visit template parameters that occur in
7902 non-deduced contexts. */
7903 bool include_nondeduced_p;
7904 struct pointer_set_t *visited;
7905 };
7906
7907 /* Called from for_each_template_parm via walk_tree. */
7908
7909 static tree
for_each_template_parm_r(tree * tp,int * walk_subtrees,void * d)7910 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7911 {
7912 tree t = *tp;
7913 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7914 tree_fn_t fn = pfd->fn;
7915 void *data = pfd->data;
7916
7917 if (TYPE_P (t)
7918 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7919 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7920 pfd->include_nondeduced_p))
7921 return error_mark_node;
7922
7923 switch (TREE_CODE (t))
7924 {
7925 case RECORD_TYPE:
7926 if (TYPE_PTRMEMFUNC_P (t))
7927 break;
7928 /* Fall through. */
7929
7930 case UNION_TYPE:
7931 case ENUMERAL_TYPE:
7932 if (!TYPE_TEMPLATE_INFO (t))
7933 *walk_subtrees = 0;
7934 else if (for_each_template_parm (TYPE_TI_ARGS (t),
7935 fn, data, pfd->visited,
7936 pfd->include_nondeduced_p))
7937 return error_mark_node;
7938 break;
7939
7940 case INTEGER_TYPE:
7941 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7942 fn, data, pfd->visited,
7943 pfd->include_nondeduced_p)
7944 || for_each_template_parm (TYPE_MAX_VALUE (t),
7945 fn, data, pfd->visited,
7946 pfd->include_nondeduced_p))
7947 return error_mark_node;
7948 break;
7949
7950 case METHOD_TYPE:
7951 /* Since we're not going to walk subtrees, we have to do this
7952 explicitly here. */
7953 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7954 pfd->visited, pfd->include_nondeduced_p))
7955 return error_mark_node;
7956 /* Fall through. */
7957
7958 case FUNCTION_TYPE:
7959 /* Check the return type. */
7960 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7961 pfd->include_nondeduced_p))
7962 return error_mark_node;
7963
7964 /* Check the parameter types. Since default arguments are not
7965 instantiated until they are needed, the TYPE_ARG_TYPES may
7966 contain expressions that involve template parameters. But,
7967 no-one should be looking at them yet. And, once they're
7968 instantiated, they don't contain template parameters, so
7969 there's no point in looking at them then, either. */
7970 {
7971 tree parm;
7972
7973 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7974 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7975 pfd->visited, pfd->include_nondeduced_p))
7976 return error_mark_node;
7977
7978 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7979 want walk_tree walking into them itself. */
7980 *walk_subtrees = 0;
7981 }
7982 break;
7983
7984 case TYPEOF_TYPE:
7985 case UNDERLYING_TYPE:
7986 if (pfd->include_nondeduced_p
7987 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7988 pfd->visited,
7989 pfd->include_nondeduced_p))
7990 return error_mark_node;
7991 break;
7992
7993 case FUNCTION_DECL:
7994 case VAR_DECL:
7995 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7996 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7997 pfd->visited, pfd->include_nondeduced_p))
7998 return error_mark_node;
7999 /* Fall through. */
8000
8001 case PARM_DECL:
8002 case CONST_DECL:
8003 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
8004 && for_each_template_parm (DECL_INITIAL (t), fn, data,
8005 pfd->visited, pfd->include_nondeduced_p))
8006 return error_mark_node;
8007 if (DECL_CONTEXT (t)
8008 && pfd->include_nondeduced_p
8009 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
8010 pfd->visited, pfd->include_nondeduced_p))
8011 return error_mark_node;
8012 break;
8013
8014 case BOUND_TEMPLATE_TEMPLATE_PARM:
8015 /* Record template parameters such as `T' inside `TT<T>'. */
8016 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
8017 pfd->include_nondeduced_p))
8018 return error_mark_node;
8019 /* Fall through. */
8020
8021 case TEMPLATE_TEMPLATE_PARM:
8022 case TEMPLATE_TYPE_PARM:
8023 case TEMPLATE_PARM_INDEX:
8024 if (fn && (*fn)(t, data))
8025 return error_mark_node;
8026 else if (!fn)
8027 return error_mark_node;
8028 break;
8029
8030 case TEMPLATE_DECL:
8031 /* A template template parameter is encountered. */
8032 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
8033 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
8034 pfd->include_nondeduced_p))
8035 return error_mark_node;
8036
8037 /* Already substituted template template parameter */
8038 *walk_subtrees = 0;
8039 break;
8040
8041 case TYPENAME_TYPE:
8042 if (!fn
8043 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
8044 data, pfd->visited,
8045 pfd->include_nondeduced_p))
8046 return error_mark_node;
8047 break;
8048
8049 case CONSTRUCTOR:
8050 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
8051 && pfd->include_nondeduced_p
8052 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
8053 (TREE_TYPE (t)), fn, data,
8054 pfd->visited, pfd->include_nondeduced_p))
8055 return error_mark_node;
8056 break;
8057
8058 case INDIRECT_REF:
8059 case COMPONENT_REF:
8060 /* If there's no type, then this thing must be some expression
8061 involving template parameters. */
8062 if (!fn && !TREE_TYPE (t))
8063 return error_mark_node;
8064 break;
8065
8066 case MODOP_EXPR:
8067 case CAST_EXPR:
8068 case IMPLICIT_CONV_EXPR:
8069 case REINTERPRET_CAST_EXPR:
8070 case CONST_CAST_EXPR:
8071 case STATIC_CAST_EXPR:
8072 case DYNAMIC_CAST_EXPR:
8073 case ARROW_EXPR:
8074 case DOTSTAR_EXPR:
8075 case TYPEID_EXPR:
8076 case PSEUDO_DTOR_EXPR:
8077 if (!fn)
8078 return error_mark_node;
8079 break;
8080
8081 default:
8082 break;
8083 }
8084
8085 /* We didn't find any template parameters we liked. */
8086 return NULL_TREE;
8087 }
8088
8089 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8090 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8091 call FN with the parameter and the DATA.
8092 If FN returns nonzero, the iteration is terminated, and
8093 for_each_template_parm returns 1. Otherwise, the iteration
8094 continues. If FN never returns a nonzero value, the value
8095 returned by for_each_template_parm is 0. If FN is NULL, it is
8096 considered to be the function which always returns 1.
8097
8098 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8099 parameters that occur in non-deduced contexts. When false, only
8100 visits those template parameters that can be deduced. */
8101
8102 static int
for_each_template_parm(tree t,tree_fn_t fn,void * data,struct pointer_set_t * visited,bool include_nondeduced_p)8103 for_each_template_parm (tree t, tree_fn_t fn, void* data,
8104 struct pointer_set_t *visited,
8105 bool include_nondeduced_p)
8106 {
8107 struct pair_fn_data pfd;
8108 int result;
8109
8110 /* Set up. */
8111 pfd.fn = fn;
8112 pfd.data = data;
8113 pfd.include_nondeduced_p = include_nondeduced_p;
8114
8115 /* Walk the tree. (Conceptually, we would like to walk without
8116 duplicates, but for_each_template_parm_r recursively calls
8117 for_each_template_parm, so we would need to reorganize a fair
8118 bit to use walk_tree_without_duplicates, so we keep our own
8119 visited list.) */
8120 if (visited)
8121 pfd.visited = visited;
8122 else
8123 pfd.visited = pointer_set_create ();
8124 result = cp_walk_tree (&t,
8125 for_each_template_parm_r,
8126 &pfd,
8127 pfd.visited) != NULL_TREE;
8128
8129 /* Clean up. */
8130 if (!visited)
8131 {
8132 pointer_set_destroy (pfd.visited);
8133 pfd.visited = 0;
8134 }
8135
8136 return result;
8137 }
8138
8139 /* Returns true if T depends on any template parameter. */
8140
8141 int
uses_template_parms(tree t)8142 uses_template_parms (tree t)
8143 {
8144 bool dependent_p;
8145 int saved_processing_template_decl;
8146
8147 saved_processing_template_decl = processing_template_decl;
8148 if (!saved_processing_template_decl)
8149 processing_template_decl = 1;
8150 if (TYPE_P (t))
8151 dependent_p = dependent_type_p (t);
8152 else if (TREE_CODE (t) == TREE_VEC)
8153 dependent_p = any_dependent_template_arguments_p (t);
8154 else if (TREE_CODE (t) == TREE_LIST)
8155 dependent_p = (uses_template_parms (TREE_VALUE (t))
8156 || uses_template_parms (TREE_CHAIN (t)));
8157 else if (TREE_CODE (t) == TYPE_DECL)
8158 dependent_p = dependent_type_p (TREE_TYPE (t));
8159 else if (DECL_P (t)
8160 || EXPR_P (t)
8161 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
8162 || TREE_CODE (t) == OVERLOAD
8163 || BASELINK_P (t)
8164 || identifier_p (t)
8165 || TREE_CODE (t) == TRAIT_EXPR
8166 || TREE_CODE (t) == CONSTRUCTOR
8167 || CONSTANT_CLASS_P (t))
8168 dependent_p = (type_dependent_expression_p (t)
8169 || value_dependent_expression_p (t));
8170 else
8171 {
8172 gcc_assert (t == error_mark_node);
8173 dependent_p = false;
8174 }
8175
8176 processing_template_decl = saved_processing_template_decl;
8177
8178 return dependent_p;
8179 }
8180
8181 /* Returns true iff current_function_decl is an incompletely instantiated
8182 template. Useful instead of processing_template_decl because the latter
8183 is set to 0 during fold_non_dependent_expr. */
8184
8185 bool
in_template_function(void)8186 in_template_function (void)
8187 {
8188 tree fn = current_function_decl;
8189 bool ret;
8190 ++processing_template_decl;
8191 ret = (fn && DECL_LANG_SPECIFIC (fn)
8192 && DECL_TEMPLATE_INFO (fn)
8193 && any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
8194 --processing_template_decl;
8195 return ret;
8196 }
8197
8198 /* Returns true if T depends on any template parameter with level LEVEL. */
8199
8200 int
uses_template_parms_level(tree t,int level)8201 uses_template_parms_level (tree t, int level)
8202 {
8203 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
8204 /*include_nondeduced_p=*/true);
8205 }
8206
8207 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8208 ill-formed translation unit, i.e. a variable or function that isn't
8209 usable in a constant expression. */
8210
8211 static inline bool
neglectable_inst_p(tree d)8212 neglectable_inst_p (tree d)
8213 {
8214 return (DECL_P (d)
8215 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
8216 : decl_maybe_constant_var_p (d)));
8217 }
8218
8219 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8220 neglectable and instantiated from within an erroneous instantiation. */
8221
8222 static bool
limit_bad_template_recursion(tree decl)8223 limit_bad_template_recursion (tree decl)
8224 {
8225 struct tinst_level *lev = current_tinst_level;
8226 int errs = errorcount + sorrycount;
8227 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
8228 return false;
8229
8230 for (; lev; lev = lev->next)
8231 if (neglectable_inst_p (lev->decl))
8232 break;
8233
8234 return (lev && errs > lev->errors);
8235 }
8236
8237 static int tinst_depth;
8238 extern int max_tinst_depth;
8239 int depth_reached;
8240
8241 static GTY(()) struct tinst_level *last_error_tinst_level;
8242
8243 /* We're starting to instantiate D; record the template instantiation context
8244 for diagnostics and to restore it later. */
8245
8246 int
push_tinst_level(tree d)8247 push_tinst_level (tree d)
8248 {
8249 struct tinst_level *new_level;
8250
8251 if (tinst_depth >= max_tinst_depth)
8252 {
8253 last_error_tinst_level = current_tinst_level;
8254 if (TREE_CODE (d) == TREE_LIST)
8255 error ("template instantiation depth exceeds maximum of %d (use "
8256 "-ftemplate-depth= to increase the maximum) substituting %qS",
8257 max_tinst_depth, d);
8258 else
8259 error ("template instantiation depth exceeds maximum of %d (use "
8260 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8261 max_tinst_depth, d);
8262
8263 print_instantiation_context ();
8264
8265 return 0;
8266 }
8267
8268 /* If the current instantiation caused problems, don't let it instantiate
8269 anything else. Do allow deduction substitution and decls usable in
8270 constant expressions. */
8271 if (limit_bad_template_recursion (d))
8272 return 0;
8273
8274 new_level = ggc_alloc_tinst_level ();
8275 new_level->decl = d;
8276 new_level->locus = input_location;
8277 new_level->errors = errorcount+sorrycount;
8278 new_level->in_system_header_p = in_system_header_at (input_location);
8279 new_level->next = current_tinst_level;
8280 current_tinst_level = new_level;
8281
8282 ++tinst_depth;
8283 if (GATHER_STATISTICS && (tinst_depth > depth_reached))
8284 depth_reached = tinst_depth;
8285
8286 return 1;
8287 }
8288
8289 /* We're done instantiating this template; return to the instantiation
8290 context. */
8291
8292 void
pop_tinst_level(void)8293 pop_tinst_level (void)
8294 {
8295 /* Restore the filename and line number stashed away when we started
8296 this instantiation. */
8297 input_location = current_tinst_level->locus;
8298 current_tinst_level = current_tinst_level->next;
8299 --tinst_depth;
8300 }
8301
8302 /* We're instantiating a deferred template; restore the template
8303 instantiation context in which the instantiation was requested, which
8304 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8305
8306 static tree
reopen_tinst_level(struct tinst_level * level)8307 reopen_tinst_level (struct tinst_level *level)
8308 {
8309 struct tinst_level *t;
8310
8311 tinst_depth = 0;
8312 for (t = level; t; t = t->next)
8313 ++tinst_depth;
8314
8315 current_tinst_level = level;
8316 pop_tinst_level ();
8317 if (current_tinst_level)
8318 current_tinst_level->errors = errorcount+sorrycount;
8319 return level->decl;
8320 }
8321
8322 /* Returns the TINST_LEVEL which gives the original instantiation
8323 context. */
8324
8325 struct tinst_level *
outermost_tinst_level(void)8326 outermost_tinst_level (void)
8327 {
8328 struct tinst_level *level = current_tinst_level;
8329 if (level)
8330 while (level->next)
8331 level = level->next;
8332 return level;
8333 }
8334
8335 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8336 vector of template arguments, as for tsubst.
8337
8338 Returns an appropriate tsubst'd friend declaration. */
8339
8340 static tree
tsubst_friend_function(tree decl,tree args)8341 tsubst_friend_function (tree decl, tree args)
8342 {
8343 tree new_friend;
8344
8345 if (TREE_CODE (decl) == FUNCTION_DECL
8346 && DECL_TEMPLATE_INSTANTIATION (decl)
8347 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8348 /* This was a friend declared with an explicit template
8349 argument list, e.g.:
8350
8351 friend void f<>(T);
8352
8353 to indicate that f was a template instantiation, not a new
8354 function declaration. Now, we have to figure out what
8355 instantiation of what template. */
8356 {
8357 tree template_id, arglist, fns;
8358 tree new_args;
8359 tree tmpl;
8360 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8361
8362 /* Friend functions are looked up in the containing namespace scope.
8363 We must enter that scope, to avoid finding member functions of the
8364 current class with same name. */
8365 push_nested_namespace (ns);
8366 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8367 tf_warning_or_error, NULL_TREE,
8368 /*integral_constant_expression_p=*/false);
8369 pop_nested_namespace (ns);
8370 arglist = tsubst (DECL_TI_ARGS (decl), args,
8371 tf_warning_or_error, NULL_TREE);
8372 template_id = lookup_template_function (fns, arglist);
8373
8374 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8375 tmpl = determine_specialization (template_id, new_friend,
8376 &new_args,
8377 /*need_member_template=*/0,
8378 TREE_VEC_LENGTH (args),
8379 tsk_none);
8380 return instantiate_template (tmpl, new_args, tf_error);
8381 }
8382
8383 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8384
8385 /* The NEW_FRIEND will look like an instantiation, to the
8386 compiler, but is not an instantiation from the point of view of
8387 the language. For example, we might have had:
8388
8389 template <class T> struct S {
8390 template <class U> friend void f(T, U);
8391 };
8392
8393 Then, in S<int>, template <class U> void f(int, U) is not an
8394 instantiation of anything. */
8395 if (new_friend == error_mark_node)
8396 return error_mark_node;
8397
8398 DECL_USE_TEMPLATE (new_friend) = 0;
8399 if (TREE_CODE (decl) == TEMPLATE_DECL)
8400 {
8401 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8402 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8403 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8404 }
8405
8406 /* The mangled name for the NEW_FRIEND is incorrect. The function
8407 is not a template instantiation and should not be mangled like
8408 one. Therefore, we forget the mangling here; we'll recompute it
8409 later if we need it. */
8410 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8411 {
8412 SET_DECL_RTL (new_friend, NULL);
8413 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8414 }
8415
8416 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8417 {
8418 tree old_decl;
8419 tree new_friend_template_info;
8420 tree new_friend_result_template_info;
8421 tree ns;
8422 int new_friend_is_defn;
8423
8424 /* We must save some information from NEW_FRIEND before calling
8425 duplicate decls since that function will free NEW_FRIEND if
8426 possible. */
8427 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8428 new_friend_is_defn =
8429 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8430 (template_for_substitution (new_friend)))
8431 != NULL_TREE);
8432 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8433 {
8434 /* This declaration is a `primary' template. */
8435 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8436
8437 new_friend_result_template_info
8438 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8439 }
8440 else
8441 new_friend_result_template_info = NULL_TREE;
8442
8443 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8444 if (new_friend_is_defn)
8445 DECL_INITIAL (new_friend) = error_mark_node;
8446
8447 /* Inside pushdecl_namespace_level, we will push into the
8448 current namespace. However, the friend function should go
8449 into the namespace of the template. */
8450 ns = decl_namespace_context (new_friend);
8451 push_nested_namespace (ns);
8452 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8453 pop_nested_namespace (ns);
8454
8455 if (old_decl == error_mark_node)
8456 return error_mark_node;
8457
8458 if (old_decl != new_friend)
8459 {
8460 /* This new friend declaration matched an existing
8461 declaration. For example, given:
8462
8463 template <class T> void f(T);
8464 template <class U> class C {
8465 template <class T> friend void f(T) {}
8466 };
8467
8468 the friend declaration actually provides the definition
8469 of `f', once C has been instantiated for some type. So,
8470 old_decl will be the out-of-class template declaration,
8471 while new_friend is the in-class definition.
8472
8473 But, if `f' was called before this point, the
8474 instantiation of `f' will have DECL_TI_ARGS corresponding
8475 to `T' but not to `U', references to which might appear
8476 in the definition of `f'. Previously, the most general
8477 template for an instantiation of `f' was the out-of-class
8478 version; now it is the in-class version. Therefore, we
8479 run through all specialization of `f', adding to their
8480 DECL_TI_ARGS appropriately. In particular, they need a
8481 new set of outer arguments, corresponding to the
8482 arguments for this class instantiation.
8483
8484 The same situation can arise with something like this:
8485
8486 friend void f(int);
8487 template <class T> class C {
8488 friend void f(T) {}
8489 };
8490
8491 when `C<int>' is instantiated. Now, `f(int)' is defined
8492 in the class. */
8493
8494 if (!new_friend_is_defn)
8495 /* On the other hand, if the in-class declaration does
8496 *not* provide a definition, then we don't want to alter
8497 existing definitions. We can just leave everything
8498 alone. */
8499 ;
8500 else
8501 {
8502 tree new_template = TI_TEMPLATE (new_friend_template_info);
8503 tree new_args = TI_ARGS (new_friend_template_info);
8504
8505 /* Overwrite whatever template info was there before, if
8506 any, with the new template information pertaining to
8507 the declaration. */
8508 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8509
8510 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8511 {
8512 /* We should have called reregister_specialization in
8513 duplicate_decls. */
8514 gcc_assert (retrieve_specialization (new_template,
8515 new_args, 0)
8516 == old_decl);
8517
8518 /* Instantiate it if the global has already been used. */
8519 if (DECL_ODR_USED (old_decl))
8520 instantiate_decl (old_decl, /*defer_ok=*/true,
8521 /*expl_inst_class_mem_p=*/false);
8522 }
8523 else
8524 {
8525 tree t;
8526
8527 /* Indicate that the old function template is a partial
8528 instantiation. */
8529 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8530 = new_friend_result_template_info;
8531
8532 gcc_assert (new_template
8533 == most_general_template (new_template));
8534 gcc_assert (new_template != old_decl);
8535
8536 /* Reassign any specializations already in the hash table
8537 to the new more general template, and add the
8538 additional template args. */
8539 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8540 t != NULL_TREE;
8541 t = TREE_CHAIN (t))
8542 {
8543 tree spec = TREE_VALUE (t);
8544 spec_entry elt;
8545
8546 elt.tmpl = old_decl;
8547 elt.args = DECL_TI_ARGS (spec);
8548 elt.spec = NULL_TREE;
8549
8550 htab_remove_elt (decl_specializations, &elt);
8551
8552 DECL_TI_ARGS (spec)
8553 = add_outermost_template_args (new_args,
8554 DECL_TI_ARGS (spec));
8555
8556 register_specialization
8557 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8558
8559 }
8560 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8561 }
8562 }
8563
8564 /* The information from NEW_FRIEND has been merged into OLD_DECL
8565 by duplicate_decls. */
8566 new_friend = old_decl;
8567 }
8568 }
8569 else
8570 {
8571 tree context = DECL_CONTEXT (new_friend);
8572 bool dependent_p;
8573
8574 /* In the code
8575 template <class T> class C {
8576 template <class U> friend void C1<U>::f (); // case 1
8577 friend void C2<T>::f (); // case 2
8578 };
8579 we only need to make sure CONTEXT is a complete type for
8580 case 2. To distinguish between the two cases, we note that
8581 CONTEXT of case 1 remains dependent type after tsubst while
8582 this isn't true for case 2. */
8583 ++processing_template_decl;
8584 dependent_p = dependent_type_p (context);
8585 --processing_template_decl;
8586
8587 if (!dependent_p
8588 && !complete_type_or_else (context, NULL_TREE))
8589 return error_mark_node;
8590
8591 if (COMPLETE_TYPE_P (context))
8592 {
8593 tree fn = new_friend;
8594 /* do_friend adds the TEMPLATE_DECL for any member friend
8595 template even if it isn't a member template, i.e.
8596 template <class T> friend A<T>::f();
8597 Look through it in that case. */
8598 if (TREE_CODE (fn) == TEMPLATE_DECL
8599 && !PRIMARY_TEMPLATE_P (fn))
8600 fn = DECL_TEMPLATE_RESULT (fn);
8601 /* Check to see that the declaration is really present, and,
8602 possibly obtain an improved declaration. */
8603 fn = check_classfn (context, fn, NULL_TREE);
8604
8605 if (fn)
8606 new_friend = fn;
8607 }
8608 }
8609
8610 return new_friend;
8611 }
8612
8613 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8614 template arguments, as for tsubst.
8615
8616 Returns an appropriate tsubst'd friend type or error_mark_node on
8617 failure. */
8618
8619 static tree
tsubst_friend_class(tree friend_tmpl,tree args)8620 tsubst_friend_class (tree friend_tmpl, tree args)
8621 {
8622 tree friend_type;
8623 tree tmpl;
8624 tree context;
8625
8626 if (DECL_TEMPLATE_TEMPLATE_PARM_P (friend_tmpl))
8627 {
8628 tree t = tsubst (TREE_TYPE (friend_tmpl), args, tf_none, NULL_TREE);
8629 return TREE_TYPE (t);
8630 }
8631
8632 context = CP_DECL_CONTEXT (friend_tmpl);
8633
8634 if (context != global_namespace)
8635 {
8636 if (TREE_CODE (context) == NAMESPACE_DECL)
8637 push_nested_namespace (context);
8638 else
8639 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8640 }
8641
8642 /* Look for a class template declaration. We look for hidden names
8643 because two friend declarations of the same template are the
8644 same. For example, in:
8645
8646 struct A {
8647 template <typename> friend class F;
8648 };
8649 template <typename> struct B {
8650 template <typename> friend class F;
8651 };
8652
8653 both F templates are the same. */
8654 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8655 /*block_p=*/true, 0, LOOKUP_HIDDEN);
8656
8657 /* But, if we don't find one, it might be because we're in a
8658 situation like this:
8659
8660 template <class T>
8661 struct S {
8662 template <class U>
8663 friend struct S;
8664 };
8665
8666 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8667 for `S<int>', not the TEMPLATE_DECL. */
8668 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8669 {
8670 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8671 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8672 }
8673
8674 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8675 {
8676 /* The friend template has already been declared. Just
8677 check to see that the declarations match, and install any new
8678 default parameters. We must tsubst the default parameters,
8679 of course. We only need the innermost template parameters
8680 because that is all that redeclare_class_template will look
8681 at. */
8682 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8683 > TMPL_ARGS_DEPTH (args))
8684 {
8685 tree parms;
8686 location_t saved_input_location;
8687 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8688 args, tf_warning_or_error);
8689
8690 saved_input_location = input_location;
8691 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8692 redeclare_class_template (TREE_TYPE (tmpl), parms);
8693 input_location = saved_input_location;
8694
8695 }
8696
8697 friend_type = TREE_TYPE (tmpl);
8698 }
8699 else
8700 {
8701 /* The friend template has not already been declared. In this
8702 case, the instantiation of the template class will cause the
8703 injection of this template into the global scope. */
8704 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8705 if (tmpl == error_mark_node)
8706 return error_mark_node;
8707
8708 /* The new TMPL is not an instantiation of anything, so we
8709 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8710 the new type because that is supposed to be the corresponding
8711 template decl, i.e., TMPL. */
8712 DECL_USE_TEMPLATE (tmpl) = 0;
8713 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8714 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8715 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8716 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8717
8718 /* Inject this template into the global scope. */
8719 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8720 }
8721
8722 if (context != global_namespace)
8723 {
8724 if (TREE_CODE (context) == NAMESPACE_DECL)
8725 pop_nested_namespace (context);
8726 else
8727 pop_nested_class ();
8728 }
8729
8730 return friend_type;
8731 }
8732
8733 /* Returns zero if TYPE cannot be completed later due to circularity.
8734 Otherwise returns one. */
8735
8736 static int
can_complete_type_without_circularity(tree type)8737 can_complete_type_without_circularity (tree type)
8738 {
8739 if (type == NULL_TREE || type == error_mark_node)
8740 return 0;
8741 else if (COMPLETE_TYPE_P (type))
8742 return 1;
8743 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8744 return can_complete_type_without_circularity (TREE_TYPE (type));
8745 else if (CLASS_TYPE_P (type)
8746 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8747 return 0;
8748 else
8749 return 1;
8750 }
8751
8752 static tree tsubst_omp_clauses (tree, bool, tree, tsubst_flags_t, tree);
8753
8754 /* Apply any attributes which had to be deferred until instantiation
8755 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8756 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8757
8758 static void
apply_late_template_attributes(tree * decl_p,tree attributes,int attr_flags,tree args,tsubst_flags_t complain,tree in_decl)8759 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8760 tree args, tsubst_flags_t complain, tree in_decl)
8761 {
8762 tree last_dep = NULL_TREE;
8763 tree t;
8764 tree *p;
8765
8766 for (t = attributes; t; t = TREE_CHAIN (t))
8767 if (ATTR_IS_DEPENDENT (t))
8768 {
8769 last_dep = t;
8770 attributes = copy_list (attributes);
8771 break;
8772 }
8773
8774 if (DECL_P (*decl_p))
8775 {
8776 if (TREE_TYPE (*decl_p) == error_mark_node)
8777 return;
8778 p = &DECL_ATTRIBUTES (*decl_p);
8779 }
8780 else
8781 p = &TYPE_ATTRIBUTES (*decl_p);
8782
8783 if (last_dep)
8784 {
8785 tree late_attrs = NULL_TREE;
8786 tree *q = &late_attrs;
8787
8788 for (*p = attributes; *p; )
8789 {
8790 t = *p;
8791 if (ATTR_IS_DEPENDENT (t))
8792 {
8793 *p = TREE_CHAIN (t);
8794 TREE_CHAIN (t) = NULL_TREE;
8795 if ((flag_openmp || flag_cilkplus)
8796 && is_attribute_p ("omp declare simd",
8797 get_attribute_name (t))
8798 && TREE_VALUE (t))
8799 {
8800 tree clauses = TREE_VALUE (TREE_VALUE (t));
8801 clauses = tsubst_omp_clauses (clauses, true, args,
8802 complain, in_decl);
8803 c_omp_declare_simd_clauses_to_decls (*decl_p, clauses);
8804 clauses = finish_omp_clauses (clauses);
8805 tree parms = DECL_ARGUMENTS (*decl_p);
8806 clauses
8807 = c_omp_declare_simd_clauses_to_numbers (parms, clauses);
8808 if (clauses)
8809 TREE_VALUE (TREE_VALUE (t)) = clauses;
8810 else
8811 TREE_VALUE (t) = NULL_TREE;
8812 }
8813 /* If the first attribute argument is an identifier, don't
8814 pass it through tsubst. Attributes like mode, format,
8815 cleanup and several target specific attributes expect it
8816 unmodified. */
8817 else if (attribute_takes_identifier_p (get_attribute_name (t))
8818 && TREE_VALUE (t))
8819 {
8820 tree chain
8821 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8822 in_decl,
8823 /*integral_constant_expression_p=*/false);
8824 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8825 TREE_VALUE (t)
8826 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8827 chain);
8828 }
8829 else
8830 TREE_VALUE (t)
8831 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8832 /*integral_constant_expression_p=*/false);
8833 *q = t;
8834 q = &TREE_CHAIN (t);
8835 }
8836 else
8837 p = &TREE_CHAIN (t);
8838 }
8839
8840 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8841 }
8842 }
8843
8844 /* Perform (or defer) access check for typedefs that were referenced
8845 from within the template TMPL code.
8846 This is a subroutine of instantiate_decl and instantiate_class_template.
8847 TMPL is the template to consider and TARGS is the list of arguments of
8848 that template. */
8849
8850 static void
perform_typedefs_access_check(tree tmpl,tree targs)8851 perform_typedefs_access_check (tree tmpl, tree targs)
8852 {
8853 location_t saved_location;
8854 unsigned i;
8855 qualified_typedef_usage_t *iter;
8856
8857 if (!tmpl
8858 || (!CLASS_TYPE_P (tmpl)
8859 && TREE_CODE (tmpl) != FUNCTION_DECL))
8860 return;
8861
8862 saved_location = input_location;
8863 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (tmpl), i, iter)
8864 {
8865 tree type_decl = iter->typedef_decl;
8866 tree type_scope = iter->context;
8867
8868 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8869 continue;
8870
8871 if (uses_template_parms (type_decl))
8872 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8873 if (uses_template_parms (type_scope))
8874 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8875
8876 /* Make access check error messages point to the location
8877 of the use of the typedef. */
8878 input_location = iter->locus;
8879 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8880 type_decl, type_decl,
8881 tf_warning_or_error);
8882 }
8883 input_location = saved_location;
8884 }
8885
8886 static tree
instantiate_class_template_1(tree type)8887 instantiate_class_template_1 (tree type)
8888 {
8889 tree templ, args, pattern, t, member;
8890 tree typedecl;
8891 tree pbinfo;
8892 tree base_list;
8893 unsigned int saved_maximum_field_alignment;
8894 tree fn_context;
8895
8896 if (type == error_mark_node)
8897 return error_mark_node;
8898
8899 if (COMPLETE_OR_OPEN_TYPE_P (type)
8900 || uses_template_parms (type))
8901 return type;
8902
8903 /* Figure out which template is being instantiated. */
8904 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8905 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8906
8907 /* Determine what specialization of the original template to
8908 instantiate. */
8909 t = most_specialized_class (type, tf_warning_or_error);
8910 if (t == error_mark_node)
8911 {
8912 TYPE_BEING_DEFINED (type) = 1;
8913 return error_mark_node;
8914 }
8915 else if (t)
8916 {
8917 /* This TYPE is actually an instantiation of a partial
8918 specialization. We replace the innermost set of ARGS with
8919 the arguments appropriate for substitution. For example,
8920 given:
8921
8922 template <class T> struct S {};
8923 template <class T> struct S<T*> {};
8924
8925 and supposing that we are instantiating S<int*>, ARGS will
8926 presently be {int*} -- but we need {int}. */
8927 pattern = TREE_TYPE (t);
8928 args = TREE_PURPOSE (t);
8929 }
8930 else
8931 {
8932 pattern = TREE_TYPE (templ);
8933 args = CLASSTYPE_TI_ARGS (type);
8934 }
8935
8936 /* If the template we're instantiating is incomplete, then clearly
8937 there's nothing we can do. */
8938 if (!COMPLETE_TYPE_P (pattern))
8939 return type;
8940
8941 /* If we've recursively instantiated too many templates, stop. */
8942 if (! push_tinst_level (type))
8943 return type;
8944
8945 /* Now we're really doing the instantiation. Mark the type as in
8946 the process of being defined. */
8947 TYPE_BEING_DEFINED (type) = 1;
8948
8949 /* We may be in the middle of deferred access check. Disable
8950 it now. */
8951 push_deferring_access_checks (dk_no_deferred);
8952
8953 fn_context = decl_function_context (TYPE_MAIN_DECL (type));
8954 if (!fn_context)
8955 push_to_top_level ();
8956 /* Use #pragma pack from the template context. */
8957 saved_maximum_field_alignment = maximum_field_alignment;
8958 maximum_field_alignment = TYPE_PRECISION (pattern);
8959
8960 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8961
8962 /* Set the input location to the most specialized template definition.
8963 This is needed if tsubsting causes an error. */
8964 typedecl = TYPE_MAIN_DECL (pattern);
8965 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8966 DECL_SOURCE_LOCATION (typedecl);
8967
8968 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8969 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8970 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8971 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8972 if (ANON_AGGR_TYPE_P (pattern))
8973 SET_ANON_AGGR_TYPE_P (type);
8974 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8975 {
8976 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8977 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8978 /* Adjust visibility for template arguments. */
8979 determine_visibility (TYPE_MAIN_DECL (type));
8980 }
8981 if (CLASS_TYPE_P (type))
8982 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8983
8984 pbinfo = TYPE_BINFO (pattern);
8985
8986 /* We should never instantiate a nested class before its enclosing
8987 class; we need to look up the nested class by name before we can
8988 instantiate it, and that lookup should instantiate the enclosing
8989 class. */
8990 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8991 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8992
8993 base_list = NULL_TREE;
8994 if (BINFO_N_BASE_BINFOS (pbinfo))
8995 {
8996 tree pbase_binfo;
8997 tree pushed_scope;
8998 int i;
8999
9000 /* We must enter the scope containing the type, as that is where
9001 the accessibility of types named in dependent bases are
9002 looked up from. */
9003 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
9004
9005 /* Substitute into each of the bases to determine the actual
9006 basetypes. */
9007 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
9008 {
9009 tree base;
9010 tree access = BINFO_BASE_ACCESS (pbinfo, i);
9011 tree expanded_bases = NULL_TREE;
9012 int idx, len = 1;
9013
9014 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
9015 {
9016 expanded_bases =
9017 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
9018 args, tf_error, NULL_TREE);
9019 if (expanded_bases == error_mark_node)
9020 continue;
9021
9022 len = TREE_VEC_LENGTH (expanded_bases);
9023 }
9024
9025 for (idx = 0; idx < len; idx++)
9026 {
9027 if (expanded_bases)
9028 /* Extract the already-expanded base class. */
9029 base = TREE_VEC_ELT (expanded_bases, idx);
9030 else
9031 /* Substitute to figure out the base class. */
9032 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
9033 NULL_TREE);
9034
9035 if (base == error_mark_node)
9036 continue;
9037
9038 base_list = tree_cons (access, base, base_list);
9039 if (BINFO_VIRTUAL_P (pbase_binfo))
9040 TREE_TYPE (base_list) = integer_type_node;
9041 }
9042 }
9043
9044 /* The list is now in reverse order; correct that. */
9045 base_list = nreverse (base_list);
9046
9047 if (pushed_scope)
9048 pop_scope (pushed_scope);
9049 }
9050 /* Now call xref_basetypes to set up all the base-class
9051 information. */
9052 xref_basetypes (type, base_list);
9053
9054 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
9055 (int) ATTR_FLAG_TYPE_IN_PLACE,
9056 args, tf_error, NULL_TREE);
9057 fixup_attribute_variants (type);
9058
9059 /* Now that our base classes are set up, enter the scope of the
9060 class, so that name lookups into base classes, etc. will work
9061 correctly. This is precisely analogous to what we do in
9062 begin_class_definition when defining an ordinary non-template
9063 class, except we also need to push the enclosing classes. */
9064 push_nested_class (type);
9065
9066 /* Now members are processed in the order of declaration. */
9067 for (member = CLASSTYPE_DECL_LIST (pattern);
9068 member; member = TREE_CHAIN (member))
9069 {
9070 tree t = TREE_VALUE (member);
9071
9072 if (TREE_PURPOSE (member))
9073 {
9074 if (TYPE_P (t))
9075 {
9076 /* Build new CLASSTYPE_NESTED_UTDS. */
9077
9078 tree newtag;
9079 bool class_template_p;
9080
9081 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
9082 && TYPE_LANG_SPECIFIC (t)
9083 && CLASSTYPE_IS_TEMPLATE (t));
9084 /* If the member is a class template, then -- even after
9085 substitution -- there may be dependent types in the
9086 template argument list for the class. We increment
9087 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
9088 that function will assume that no types are dependent
9089 when outside of a template. */
9090 if (class_template_p)
9091 ++processing_template_decl;
9092 newtag = tsubst (t, args, tf_error, NULL_TREE);
9093 if (class_template_p)
9094 --processing_template_decl;
9095 if (newtag == error_mark_node)
9096 continue;
9097
9098 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
9099 {
9100 tree name = TYPE_IDENTIFIER (t);
9101
9102 if (class_template_p)
9103 /* Unfortunately, lookup_template_class sets
9104 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
9105 instantiation (i.e., for the type of a member
9106 template class nested within a template class.)
9107 This behavior is required for
9108 maybe_process_partial_specialization to work
9109 correctly, but is not accurate in this case;
9110 the TAG is not an instantiation of anything.
9111 (The corresponding TEMPLATE_DECL is an
9112 instantiation, but the TYPE is not.) */
9113 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
9114
9115 /* Now, we call pushtag to put this NEWTAG into the scope of
9116 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
9117 pushtag calling push_template_decl. We don't have to do
9118 this for enums because it will already have been done in
9119 tsubst_enum. */
9120 if (name)
9121 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
9122 pushtag (name, newtag, /*tag_scope=*/ts_current);
9123 }
9124 }
9125 else if (DECL_DECLARES_FUNCTION_P (t))
9126 {
9127 /* Build new TYPE_METHODS. */
9128 tree r;
9129
9130 if (TREE_CODE (t) == TEMPLATE_DECL)
9131 ++processing_template_decl;
9132 r = tsubst (t, args, tf_error, NULL_TREE);
9133 if (TREE_CODE (t) == TEMPLATE_DECL)
9134 --processing_template_decl;
9135 set_current_access_from_decl (r);
9136 finish_member_declaration (r);
9137 /* Instantiate members marked with attribute used. */
9138 if (r != error_mark_node && DECL_PRESERVE_P (r))
9139 mark_used (r);
9140 if (TREE_CODE (r) == FUNCTION_DECL
9141 && DECL_OMP_DECLARE_REDUCTION_P (r))
9142 cp_check_omp_declare_reduction (r);
9143 }
9144 else if (DECL_CLASS_TEMPLATE_P (t)
9145 && LAMBDA_TYPE_P (TREE_TYPE (t)))
9146 /* A closure type for a lambda in a default argument for a
9147 member template. Ignore it; it will be instantiated with
9148 the default argument. */;
9149 else
9150 {
9151 /* Build new TYPE_FIELDS. */
9152 if (TREE_CODE (t) == STATIC_ASSERT)
9153 {
9154 tree condition;
9155
9156 ++c_inhibit_evaluation_warnings;
9157 condition =
9158 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
9159 tf_warning_or_error, NULL_TREE,
9160 /*integral_constant_expression_p=*/true);
9161 --c_inhibit_evaluation_warnings;
9162
9163 finish_static_assert (condition,
9164 STATIC_ASSERT_MESSAGE (t),
9165 STATIC_ASSERT_SOURCE_LOCATION (t),
9166 /*member_p=*/true);
9167 }
9168 else if (TREE_CODE (t) != CONST_DECL)
9169 {
9170 tree r;
9171 tree vec = NULL_TREE;
9172 int len = 1;
9173
9174 /* The file and line for this declaration, to
9175 assist in error message reporting. Since we
9176 called push_tinst_level above, we don't need to
9177 restore these. */
9178 input_location = DECL_SOURCE_LOCATION (t);
9179
9180 if (TREE_CODE (t) == TEMPLATE_DECL)
9181 ++processing_template_decl;
9182 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
9183 if (TREE_CODE (t) == TEMPLATE_DECL)
9184 --processing_template_decl;
9185
9186 if (TREE_CODE (r) == TREE_VEC)
9187 {
9188 /* A capture pack became multiple fields. */
9189 vec = r;
9190 len = TREE_VEC_LENGTH (vec);
9191 }
9192
9193 for (int i = 0; i < len; ++i)
9194 {
9195 if (vec)
9196 r = TREE_VEC_ELT (vec, i);
9197 if (VAR_P (r))
9198 {
9199 /* In [temp.inst]:
9200
9201 [t]he initialization (and any associated
9202 side-effects) of a static data member does
9203 not occur unless the static data member is
9204 itself used in a way that requires the
9205 definition of the static data member to
9206 exist.
9207
9208 Therefore, we do not substitute into the
9209 initialized for the static data member here. */
9210 finish_static_data_member_decl
9211 (r,
9212 /*init=*/NULL_TREE,
9213 /*init_const_expr_p=*/false,
9214 /*asmspec_tree=*/NULL_TREE,
9215 /*flags=*/0);
9216 /* Instantiate members marked with attribute used. */
9217 if (r != error_mark_node && DECL_PRESERVE_P (r))
9218 mark_used (r);
9219 }
9220 else if (TREE_CODE (r) == FIELD_DECL)
9221 {
9222 /* Determine whether R has a valid type and can be
9223 completed later. If R is invalid, then its type
9224 is replaced by error_mark_node. */
9225 tree rtype = TREE_TYPE (r);
9226 if (can_complete_type_without_circularity (rtype))
9227 complete_type (rtype);
9228
9229 if (!COMPLETE_TYPE_P (rtype))
9230 {
9231 cxx_incomplete_type_error (r, rtype);
9232 TREE_TYPE (r) = error_mark_node;
9233 }
9234 }
9235
9236 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9237 such a thing will already have been added to the field
9238 list by tsubst_enum in finish_member_declaration in the
9239 CLASSTYPE_NESTED_UTDS case above. */
9240 if (!(TREE_CODE (r) == TYPE_DECL
9241 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
9242 && DECL_ARTIFICIAL (r)))
9243 {
9244 set_current_access_from_decl (r);
9245 finish_member_declaration (r);
9246 }
9247 }
9248 }
9249 }
9250 }
9251 else
9252 {
9253 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t)
9254 || DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9255 {
9256 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9257
9258 tree friend_type = t;
9259 bool adjust_processing_template_decl = false;
9260
9261 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9262 {
9263 /* template <class T> friend class C; */
9264 friend_type = tsubst_friend_class (friend_type, args);
9265 adjust_processing_template_decl = true;
9266 }
9267 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
9268 {
9269 /* template <class T> friend class C::D; */
9270 friend_type = tsubst (friend_type, args,
9271 tf_warning_or_error, NULL_TREE);
9272 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9273 friend_type = TREE_TYPE (friend_type);
9274 adjust_processing_template_decl = true;
9275 }
9276 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
9277 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
9278 {
9279 /* This could be either
9280
9281 friend class T::C;
9282
9283 when dependent_type_p is false or
9284
9285 template <class U> friend class T::C;
9286
9287 otherwise. */
9288 friend_type = tsubst (friend_type, args,
9289 tf_warning_or_error, NULL_TREE);
9290 /* Bump processing_template_decl for correct
9291 dependent_type_p calculation. */
9292 ++processing_template_decl;
9293 if (dependent_type_p (friend_type))
9294 adjust_processing_template_decl = true;
9295 --processing_template_decl;
9296 }
9297 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9298 && hidden_name_p (TYPE_NAME (friend_type)))
9299 {
9300 /* friend class C;
9301
9302 where C hasn't been declared yet. Let's lookup name
9303 from namespace scope directly, bypassing any name that
9304 come from dependent base class. */
9305 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9306
9307 /* The call to xref_tag_from_type does injection for friend
9308 classes. */
9309 push_nested_namespace (ns);
9310 friend_type =
9311 xref_tag_from_type (friend_type, NULL_TREE,
9312 /*tag_scope=*/ts_current);
9313 pop_nested_namespace (ns);
9314 }
9315 else if (uses_template_parms (friend_type))
9316 /* friend class C<T>; */
9317 friend_type = tsubst (friend_type, args,
9318 tf_warning_or_error, NULL_TREE);
9319 /* Otherwise it's
9320
9321 friend class C;
9322
9323 where C is already declared or
9324
9325 friend class C<int>;
9326
9327 We don't have to do anything in these cases. */
9328
9329 if (adjust_processing_template_decl)
9330 /* Trick make_friend_class into realizing that the friend
9331 we're adding is a template, not an ordinary class. It's
9332 important that we use make_friend_class since it will
9333 perform some error-checking and output cross-reference
9334 information. */
9335 ++processing_template_decl;
9336
9337 if (friend_type != error_mark_node)
9338 make_friend_class (type, friend_type, /*complain=*/false);
9339
9340 if (adjust_processing_template_decl)
9341 --processing_template_decl;
9342 }
9343 else
9344 {
9345 /* Build new DECL_FRIENDLIST. */
9346 tree r;
9347
9348 /* The file and line for this declaration, to
9349 assist in error message reporting. Since we
9350 called push_tinst_level above, we don't need to
9351 restore these. */
9352 input_location = DECL_SOURCE_LOCATION (t);
9353
9354 if (TREE_CODE (t) == TEMPLATE_DECL)
9355 {
9356 ++processing_template_decl;
9357 push_deferring_access_checks (dk_no_check);
9358 }
9359
9360 r = tsubst_friend_function (t, args);
9361 add_friend (type, r, /*complain=*/false);
9362 if (TREE_CODE (t) == TEMPLATE_DECL)
9363 {
9364 pop_deferring_access_checks ();
9365 --processing_template_decl;
9366 }
9367 }
9368 }
9369 }
9370
9371 if (tree expr = CLASSTYPE_LAMBDA_EXPR (type))
9372 {
9373 tree decl = lambda_function (type);
9374 if (decl)
9375 {
9376 if (!DECL_TEMPLATE_INFO (decl)
9377 || DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) != decl)
9378 instantiate_decl (decl, false, false);
9379
9380 /* We need to instantiate the capture list from the template
9381 after we've instantiated the closure members, but before we
9382 consider adding the conversion op. Also keep any captures
9383 that may have been added during instantiation of the op(). */
9384 tree tmpl_expr = CLASSTYPE_LAMBDA_EXPR (pattern);
9385 tree tmpl_cap
9386 = tsubst_copy_and_build (LAMBDA_EXPR_CAPTURE_LIST (tmpl_expr),
9387 args, tf_warning_or_error, NULL_TREE,
9388 false, false);
9389
9390 LAMBDA_EXPR_CAPTURE_LIST (expr)
9391 = chainon (tmpl_cap, nreverse (LAMBDA_EXPR_CAPTURE_LIST (expr)));
9392
9393 maybe_add_lambda_conv_op (type);
9394 }
9395 else
9396 gcc_assert (errorcount);
9397 }
9398
9399 /* Set the file and line number information to whatever is given for
9400 the class itself. This puts error messages involving generated
9401 implicit functions at a predictable point, and the same point
9402 that would be used for non-template classes. */
9403 input_location = DECL_SOURCE_LOCATION (typedecl);
9404
9405 unreverse_member_declarations (type);
9406 finish_struct_1 (type);
9407 TYPE_BEING_DEFINED (type) = 0;
9408
9409 /* We don't instantiate default arguments for member functions. 14.7.1:
9410
9411 The implicit instantiation of a class template specialization causes
9412 the implicit instantiation of the declarations, but not of the
9413 definitions or default arguments, of the class member functions,
9414 member classes, static data members and member templates.... */
9415
9416 /* Some typedefs referenced from within the template code need to be access
9417 checked at template instantiation time, i.e now. These types were
9418 added to the template at parsing time. Let's get those and perform
9419 the access checks then. */
9420 perform_typedefs_access_check (pattern, args);
9421 perform_deferred_access_checks (tf_warning_or_error);
9422 pop_nested_class ();
9423 maximum_field_alignment = saved_maximum_field_alignment;
9424 if (!fn_context)
9425 pop_from_top_level ();
9426 pop_deferring_access_checks ();
9427 pop_tinst_level ();
9428
9429 /* The vtable for a template class can be emitted in any translation
9430 unit in which the class is instantiated. When there is no key
9431 method, however, finish_struct_1 will already have added TYPE to
9432 the keyed_classes list. */
9433 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9434 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9435
9436 return type;
9437 }
9438
9439 /* Wrapper for instantiate_class_template_1. */
9440
9441 tree
instantiate_class_template(tree type)9442 instantiate_class_template (tree type)
9443 {
9444 tree ret;
9445 timevar_push (TV_TEMPLATE_INST);
9446 ret = instantiate_class_template_1 (type);
9447 timevar_pop (TV_TEMPLATE_INST);
9448 return ret;
9449 }
9450
9451 static tree
tsubst_template_arg(tree t,tree args,tsubst_flags_t complain,tree in_decl)9452 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9453 {
9454 tree r;
9455
9456 if (!t)
9457 r = t;
9458 else if (TYPE_P (t))
9459 r = tsubst (t, args, complain, in_decl);
9460 else
9461 {
9462 if (!(complain & tf_warning))
9463 ++c_inhibit_evaluation_warnings;
9464 r = tsubst_expr (t, args, complain, in_decl,
9465 /*integral_constant_expression_p=*/true);
9466 if (!(complain & tf_warning))
9467 --c_inhibit_evaluation_warnings;
9468 }
9469 return r;
9470 }
9471
9472 /* Given a function parameter pack TMPL_PARM and some function parameters
9473 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9474 and set *SPEC_P to point at the next point in the list. */
9475
9476 static tree
extract_fnparm_pack(tree tmpl_parm,tree * spec_p)9477 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9478 {
9479 /* Collect all of the extra "packed" parameters into an
9480 argument pack. */
9481 tree parmvec;
9482 tree parmtypevec;
9483 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9484 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9485 tree spec_parm = *spec_p;
9486 int i, len;
9487
9488 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9489 if (tmpl_parm
9490 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9491 break;
9492
9493 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9494 parmvec = make_tree_vec (len);
9495 parmtypevec = make_tree_vec (len);
9496 spec_parm = *spec_p;
9497 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9498 {
9499 TREE_VEC_ELT (parmvec, i) = spec_parm;
9500 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9501 }
9502
9503 /* Build the argument packs. */
9504 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9505 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9506 TREE_TYPE (argpack) = argtypepack;
9507 *spec_p = spec_parm;
9508
9509 return argpack;
9510 }
9511
9512 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9513 NONTYPE_ARGUMENT_PACK. */
9514
9515 static tree
make_fnparm_pack(tree spec_parm)9516 make_fnparm_pack (tree spec_parm)
9517 {
9518 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9519 }
9520
9521 /* Return true iff the Ith element of the argument pack ARG_PACK is a
9522 pack expansion. */
9523
9524 static bool
argument_pack_element_is_expansion_p(tree arg_pack,int i)9525 argument_pack_element_is_expansion_p (tree arg_pack, int i)
9526 {
9527 tree vec = ARGUMENT_PACK_ARGS (arg_pack);
9528 if (i >= TREE_VEC_LENGTH (vec))
9529 return false;
9530 return PACK_EXPANSION_P (TREE_VEC_ELT (vec, i));
9531 }
9532
9533
9534 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
9535
9536 static tree
make_argument_pack_select(tree arg_pack,unsigned index)9537 make_argument_pack_select (tree arg_pack, unsigned index)
9538 {
9539 tree aps = make_node (ARGUMENT_PACK_SELECT);
9540
9541 ARGUMENT_PACK_SELECT_FROM_PACK (aps) = arg_pack;
9542 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
9543
9544 return aps;
9545 }
9546
9547 /* This is a subroutine of tsubst_pack_expansion.
9548
9549 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
9550 mechanism to store the (non complete list of) arguments of the
9551 substitution and return a non substituted pack expansion, in order
9552 to wait for when we have enough arguments to really perform the
9553 substitution. */
9554
9555 static bool
use_pack_expansion_extra_args_p(tree parm_packs,int arg_pack_len,bool has_empty_arg)9556 use_pack_expansion_extra_args_p (tree parm_packs,
9557 int arg_pack_len,
9558 bool has_empty_arg)
9559 {
9560 /* If one pack has an expansion and another pack has a normal
9561 argument or if one pack has an empty argument and an another
9562 one hasn't then tsubst_pack_expansion cannot perform the
9563 substitution and need to fall back on the
9564 PACK_EXPANSION_EXTRA mechanism. */
9565 if (parm_packs == NULL_TREE)
9566 return false;
9567 else if (has_empty_arg)
9568 return true;
9569
9570 bool has_expansion_arg = false;
9571 for (int i = 0 ; i < arg_pack_len; ++i)
9572 {
9573 bool has_non_expansion_arg = false;
9574 for (tree parm_pack = parm_packs;
9575 parm_pack;
9576 parm_pack = TREE_CHAIN (parm_pack))
9577 {
9578 tree arg = TREE_VALUE (parm_pack);
9579
9580 if (argument_pack_element_is_expansion_p (arg, i))
9581 has_expansion_arg = true;
9582 else
9583 has_non_expansion_arg = true;
9584 }
9585
9586 if (has_expansion_arg && has_non_expansion_arg)
9587 return true;
9588 }
9589 return false;
9590 }
9591
9592 /* [temp.variadic]/6 says that:
9593
9594 The instantiation of a pack expansion [...]
9595 produces a list E1,E2, ..., En, where N is the number of elements
9596 in the pack expansion parameters.
9597
9598 This subroutine of tsubst_pack_expansion produces one of these Ei.
9599
9600 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
9601 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
9602 PATTERN, and each TREE_VALUE is its corresponding argument pack.
9603 INDEX is the index 'i' of the element Ei to produce. ARGS,
9604 COMPLAIN, and IN_DECL are the same parameters as for the
9605 tsubst_pack_expansion function.
9606
9607 The function returns the resulting Ei upon successful completion,
9608 or error_mark_node.
9609
9610 Note that this function possibly modifies the ARGS parameter, so
9611 it's the responsibility of the caller to restore it. */
9612
9613 static tree
gen_elem_of_pack_expansion_instantiation(tree pattern,tree parm_packs,unsigned index,tree args,tsubst_flags_t complain,tree in_decl)9614 gen_elem_of_pack_expansion_instantiation (tree pattern,
9615 tree parm_packs,
9616 unsigned index,
9617 tree args /* This parm gets
9618 modified. */,
9619 tsubst_flags_t complain,
9620 tree in_decl)
9621 {
9622 tree t;
9623 bool ith_elem_is_expansion = false;
9624
9625 /* For each parameter pack, change the substitution of the parameter
9626 pack to the ith argument in its argument pack, then expand the
9627 pattern. */
9628 for (tree pack = parm_packs; pack; pack = TREE_CHAIN (pack))
9629 {
9630 tree parm = TREE_PURPOSE (pack);
9631 tree arg_pack = TREE_VALUE (pack);
9632 tree aps; /* instance of ARGUMENT_PACK_SELECT. */
9633
9634 ith_elem_is_expansion |=
9635 argument_pack_element_is_expansion_p (arg_pack, index);
9636
9637 /* Select the Ith argument from the pack. */
9638 if (TREE_CODE (parm) == PARM_DECL
9639 || TREE_CODE (parm) == FIELD_DECL)
9640 {
9641 if (index == 0)
9642 {
9643 aps = make_argument_pack_select (arg_pack, index);
9644 mark_used (parm);
9645 register_local_specialization (aps, parm);
9646 }
9647 else
9648 aps = retrieve_local_specialization (parm);
9649 }
9650 else
9651 {
9652 int idx, level;
9653 template_parm_level_and_index (parm, &level, &idx);
9654
9655 if (index == 0)
9656 {
9657 aps = make_argument_pack_select (arg_pack, index);
9658 /* Update the corresponding argument. */
9659 TMPL_ARG (args, level, idx) = aps;
9660 }
9661 else
9662 /* Re-use the ARGUMENT_PACK_SELECT. */
9663 aps = TMPL_ARG (args, level, idx);
9664 }
9665 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
9666 }
9667
9668 /* Substitute into the PATTERN with the (possibly altered)
9669 arguments. */
9670 if (pattern == in_decl)
9671 /* Expanding a fixed parameter pack from
9672 coerce_template_parameter_pack. */
9673 t = tsubst_decl (pattern, args, complain);
9674 else if (!TYPE_P (pattern))
9675 t = tsubst_expr (pattern, args, complain, in_decl,
9676 /*integral_constant_expression_p=*/false);
9677 else
9678 t = tsubst (pattern, args, complain, in_decl);
9679
9680 /* If the Ith argument pack element is a pack expansion, then
9681 the Ith element resulting from the substituting is going to
9682 be a pack expansion as well. */
9683 if (ith_elem_is_expansion)
9684 t = make_pack_expansion (t);
9685
9686 return t;
9687 }
9688
9689 /* Substitute ARGS into T, which is an pack expansion
9690 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9691 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9692 (if only a partial substitution could be performed) or
9693 ERROR_MARK_NODE if there was an error. */
9694 tree
tsubst_pack_expansion(tree t,tree args,tsubst_flags_t complain,tree in_decl)9695 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9696 tree in_decl)
9697 {
9698 tree pattern;
9699 tree pack, packs = NULL_TREE;
9700 bool unsubstituted_packs = false;
9701 int i, len = -1;
9702 tree result;
9703 struct pointer_map_t *saved_local_specializations = NULL;
9704 bool need_local_specializations = false;
9705 int levels;
9706
9707 gcc_assert (PACK_EXPANSION_P (t));
9708 pattern = PACK_EXPANSION_PATTERN (t);
9709
9710 /* Add in any args remembered from an earlier partial instantiation. */
9711 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9712
9713 levels = TMPL_ARGS_DEPTH (args);
9714
9715 /* Determine the argument packs that will instantiate the parameter
9716 packs used in the expansion expression. While we're at it,
9717 compute the number of arguments to be expanded and make sure it
9718 is consistent. */
9719 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9720 pack = TREE_CHAIN (pack))
9721 {
9722 tree parm_pack = TREE_VALUE (pack);
9723 tree arg_pack = NULL_TREE;
9724 tree orig_arg = NULL_TREE;
9725 int level = 0;
9726
9727 if (TREE_CODE (parm_pack) == BASES)
9728 {
9729 if (BASES_DIRECT (parm_pack))
9730 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9731 args, complain, in_decl, false));
9732 else
9733 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9734 args, complain, in_decl, false));
9735 }
9736 if (TREE_CODE (parm_pack) == PARM_DECL)
9737 {
9738 if (PACK_EXPANSION_LOCAL_P (t))
9739 arg_pack = retrieve_local_specialization (parm_pack);
9740 else
9741 {
9742 /* We can't rely on local_specializations for a parameter
9743 name used later in a function declaration (such as in a
9744 late-specified return type). Even if it exists, it might
9745 have the wrong value for a recursive call. Just make a
9746 dummy decl, since it's only used for its type. */
9747 arg_pack = tsubst_decl (parm_pack, args, complain);
9748 if (arg_pack && DECL_PACK_P (arg_pack))
9749 /* Partial instantiation of the parm_pack, we can't build
9750 up an argument pack yet. */
9751 arg_pack = NULL_TREE;
9752 else
9753 arg_pack = make_fnparm_pack (arg_pack);
9754 need_local_specializations = true;
9755 }
9756 }
9757 else if (TREE_CODE (parm_pack) == FIELD_DECL)
9758 arg_pack = tsubst_copy (parm_pack, args, complain, in_decl);
9759 else
9760 {
9761 int idx;
9762 template_parm_level_and_index (parm_pack, &level, &idx);
9763
9764 if (level <= levels)
9765 arg_pack = TMPL_ARG (args, level, idx);
9766 }
9767
9768 orig_arg = arg_pack;
9769 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9770 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9771
9772 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9773 /* This can only happen if we forget to expand an argument
9774 pack somewhere else. Just return an error, silently. */
9775 {
9776 result = make_tree_vec (1);
9777 TREE_VEC_ELT (result, 0) = error_mark_node;
9778 return result;
9779 }
9780
9781 if (arg_pack)
9782 {
9783 int my_len =
9784 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9785
9786 /* Don't bother trying to do a partial substitution with
9787 incomplete packs; we'll try again after deduction. */
9788 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9789 return t;
9790
9791 if (len < 0)
9792 len = my_len;
9793 else if (len != my_len)
9794 {
9795 if (!(complain & tf_error))
9796 /* Fail quietly. */;
9797 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9798 error ("mismatched argument pack lengths while expanding "
9799 "%<%T%>",
9800 pattern);
9801 else
9802 error ("mismatched argument pack lengths while expanding "
9803 "%<%E%>",
9804 pattern);
9805 return error_mark_node;
9806 }
9807
9808 /* Keep track of the parameter packs and their corresponding
9809 argument packs. */
9810 packs = tree_cons (parm_pack, arg_pack, packs);
9811 TREE_TYPE (packs) = orig_arg;
9812 }
9813 else
9814 {
9815 /* We can't substitute for this parameter pack. We use a flag as
9816 well as the missing_level counter because function parameter
9817 packs don't have a level. */
9818 unsubstituted_packs = true;
9819 }
9820 }
9821
9822 /* If the expansion is just T..., return the matching argument pack. */
9823 if (!unsubstituted_packs
9824 && TREE_PURPOSE (packs) == pattern)
9825 {
9826 tree args = ARGUMENT_PACK_ARGS (TREE_VALUE (packs));
9827 if (TREE_CODE (t) == TYPE_PACK_EXPANSION
9828 || pack_expansion_args_count (args))
9829 return args;
9830 /* Otherwise use the normal path so we get convert_from_reference. */
9831 }
9832
9833 /* We cannot expand this expansion expression, because we don't have
9834 all of the argument packs we need. */
9835 if (use_pack_expansion_extra_args_p (packs, len, unsubstituted_packs))
9836 {
9837 /* We got some full packs, but we can't substitute them in until we
9838 have values for all the packs. So remember these until then. */
9839
9840 t = make_pack_expansion (pattern);
9841 PACK_EXPANSION_EXTRA_ARGS (t) = args;
9842 return t;
9843 }
9844 else if (unsubstituted_packs)
9845 {
9846 /* There were no real arguments, we're just replacing a parameter
9847 pack with another version of itself. Substitute into the
9848 pattern and return a PACK_EXPANSION_*. The caller will need to
9849 deal with that. */
9850 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9851 t = tsubst_expr (pattern, args, complain, in_decl,
9852 /*integral_constant_expression_p=*/false);
9853 else
9854 t = tsubst (pattern, args, complain, in_decl);
9855 t = make_pack_expansion (t);
9856 return t;
9857 }
9858
9859 gcc_assert (len >= 0);
9860
9861 if (need_local_specializations)
9862 {
9863 /* We're in a late-specified return type, so create our own local
9864 specializations map; the current map is either NULL or (in the
9865 case of recursive unification) might have bindings that we don't
9866 want to use or alter. */
9867 saved_local_specializations = local_specializations;
9868 local_specializations = pointer_map_create ();
9869 }
9870
9871 /* For each argument in each argument pack, substitute into the
9872 pattern. */
9873 result = make_tree_vec (len);
9874 for (i = 0; i < len; ++i)
9875 {
9876 t = gen_elem_of_pack_expansion_instantiation (pattern, packs,
9877 i,
9878 args, complain,
9879 in_decl);
9880 TREE_VEC_ELT (result, i) = t;
9881 if (t == error_mark_node)
9882 {
9883 result = error_mark_node;
9884 break;
9885 }
9886 }
9887
9888 /* Update ARGS to restore the substitution from parameter packs to
9889 their argument packs. */
9890 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9891 {
9892 tree parm = TREE_PURPOSE (pack);
9893
9894 if (TREE_CODE (parm) == PARM_DECL
9895 || TREE_CODE (parm) == FIELD_DECL)
9896 register_local_specialization (TREE_TYPE (pack), parm);
9897 else
9898 {
9899 int idx, level;
9900
9901 if (TREE_VALUE (pack) == NULL_TREE)
9902 continue;
9903
9904 template_parm_level_and_index (parm, &level, &idx);
9905
9906 /* Update the corresponding argument. */
9907 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9908 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9909 TREE_TYPE (pack);
9910 else
9911 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9912 }
9913 }
9914
9915 if (need_local_specializations)
9916 {
9917 pointer_map_destroy (local_specializations);
9918 local_specializations = saved_local_specializations;
9919 }
9920
9921 return result;
9922 }
9923
9924 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9925 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9926 parameter packs; all parms generated from a function parameter pack will
9927 have the same DECL_PARM_INDEX. */
9928
9929 tree
get_pattern_parm(tree parm,tree tmpl)9930 get_pattern_parm (tree parm, tree tmpl)
9931 {
9932 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9933 tree patparm;
9934
9935 if (DECL_ARTIFICIAL (parm))
9936 {
9937 for (patparm = DECL_ARGUMENTS (pattern);
9938 patparm; patparm = DECL_CHAIN (patparm))
9939 if (DECL_ARTIFICIAL (patparm)
9940 && DECL_NAME (parm) == DECL_NAME (patparm))
9941 break;
9942 }
9943 else
9944 {
9945 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9946 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9947 gcc_assert (DECL_PARM_INDEX (patparm)
9948 == DECL_PARM_INDEX (parm));
9949 }
9950
9951 return patparm;
9952 }
9953
9954 /* Substitute ARGS into the vector or list of template arguments T. */
9955
9956 static tree
tsubst_template_args(tree t,tree args,tsubst_flags_t complain,tree in_decl)9957 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9958 {
9959 tree orig_t = t;
9960 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9961 tree *elts;
9962
9963 if (t == error_mark_node)
9964 return error_mark_node;
9965
9966 len = TREE_VEC_LENGTH (t);
9967 elts = XALLOCAVEC (tree, len);
9968
9969 for (i = 0; i < len; i++)
9970 {
9971 tree orig_arg = TREE_VEC_ELT (t, i);
9972 tree new_arg;
9973
9974 if (TREE_CODE (orig_arg) == TREE_VEC)
9975 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9976 else if (PACK_EXPANSION_P (orig_arg))
9977 {
9978 /* Substitute into an expansion expression. */
9979 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9980
9981 if (TREE_CODE (new_arg) == TREE_VEC)
9982 /* Add to the expanded length adjustment the number of
9983 expanded arguments. We subtract one from this
9984 measurement, because the argument pack expression
9985 itself is already counted as 1 in
9986 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9987 the argument pack is empty. */
9988 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9989 }
9990 else if (ARGUMENT_PACK_P (orig_arg))
9991 {
9992 /* Substitute into each of the arguments. */
9993 new_arg = TYPE_P (orig_arg)
9994 ? cxx_make_type (TREE_CODE (orig_arg))
9995 : make_node (TREE_CODE (orig_arg));
9996
9997 SET_ARGUMENT_PACK_ARGS (
9998 new_arg,
9999 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
10000 args, complain, in_decl));
10001
10002 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
10003 new_arg = error_mark_node;
10004
10005 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
10006 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
10007 complain, in_decl);
10008 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
10009
10010 if (TREE_TYPE (new_arg) == error_mark_node)
10011 new_arg = error_mark_node;
10012 }
10013 }
10014 else
10015 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
10016
10017 if (new_arg == error_mark_node)
10018 return error_mark_node;
10019
10020 elts[i] = new_arg;
10021 if (new_arg != orig_arg)
10022 need_new = 1;
10023 }
10024
10025 if (!need_new)
10026 return t;
10027
10028 /* Make space for the expanded arguments coming from template
10029 argument packs. */
10030 t = make_tree_vec (len + expanded_len_adjust);
10031 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
10032 arguments for a member template.
10033 In that case each TREE_VEC in ORIG_T represents a level of template
10034 arguments, and ORIG_T won't carry any non defaulted argument count.
10035 It will rather be the nested TREE_VECs that will carry one.
10036 In other words, ORIG_T carries a non defaulted argument count only
10037 if it doesn't contain any nested TREE_VEC. */
10038 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
10039 {
10040 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
10041 count += expanded_len_adjust;
10042 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
10043 }
10044 for (i = 0, out = 0; i < len; i++)
10045 {
10046 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
10047 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
10048 && TREE_CODE (elts[i]) == TREE_VEC)
10049 {
10050 int idx;
10051
10052 /* Now expand the template argument pack "in place". */
10053 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
10054 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
10055 }
10056 else
10057 {
10058 TREE_VEC_ELT (t, out) = elts[i];
10059 out++;
10060 }
10061 }
10062
10063 return t;
10064 }
10065
10066 /* Return the result of substituting ARGS into the template parameters
10067 given by PARMS. If there are m levels of ARGS and m + n levels of
10068 PARMS, then the result will contain n levels of PARMS. For
10069 example, if PARMS is `template <class T> template <class U>
10070 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
10071 result will be `template <int*, double, class V>'. */
10072
10073 static tree
tsubst_template_parms(tree parms,tree args,tsubst_flags_t complain)10074 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
10075 {
10076 tree r = NULL_TREE;
10077 tree* new_parms;
10078
10079 /* When substituting into a template, we must set
10080 PROCESSING_TEMPLATE_DECL as the template parameters may be
10081 dependent if they are based on one-another, and the dependency
10082 predicates are short-circuit outside of templates. */
10083 ++processing_template_decl;
10084
10085 for (new_parms = &r;
10086 parms && TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
10087 new_parms = &(TREE_CHAIN (*new_parms)),
10088 parms = TREE_CHAIN (parms))
10089 {
10090 tree new_vec =
10091 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
10092 int i;
10093
10094 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
10095 {
10096 tree tuple;
10097
10098 if (parms == error_mark_node)
10099 continue;
10100
10101 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
10102
10103 if (tuple == error_mark_node)
10104 continue;
10105
10106 TREE_VEC_ELT (new_vec, i) =
10107 tsubst_template_parm (tuple, args, complain);
10108 }
10109
10110 *new_parms =
10111 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
10112 - TMPL_ARGS_DEPTH (args)),
10113 new_vec, NULL_TREE);
10114 }
10115
10116 --processing_template_decl;
10117
10118 return r;
10119 }
10120
10121 /* Return the result of substituting ARGS into one template parameter
10122 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
10123 parameter and which TREE_PURPOSE is the default argument of the
10124 template parameter. */
10125
10126 static tree
tsubst_template_parm(tree t,tree args,tsubst_flags_t complain)10127 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
10128 {
10129 tree default_value, parm_decl;
10130
10131 if (args == NULL_TREE
10132 || t == NULL_TREE
10133 || t == error_mark_node)
10134 return t;
10135
10136 gcc_assert (TREE_CODE (t) == TREE_LIST);
10137
10138 default_value = TREE_PURPOSE (t);
10139 parm_decl = TREE_VALUE (t);
10140
10141 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
10142 if (TREE_CODE (parm_decl) == PARM_DECL
10143 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
10144 parm_decl = error_mark_node;
10145 default_value = tsubst_template_arg (default_value, args,
10146 complain, NULL_TREE);
10147
10148 return build_tree_list (default_value, parm_decl);
10149 }
10150
10151 /* Substitute the ARGS into the indicated aggregate (or enumeration)
10152 type T. If T is not an aggregate or enumeration type, it is
10153 handled as if by tsubst. IN_DECL is as for tsubst. If
10154 ENTERING_SCOPE is nonzero, T is the context for a template which
10155 we are presently tsubst'ing. Return the substituted value. */
10156
10157 static tree
tsubst_aggr_type(tree t,tree args,tsubst_flags_t complain,tree in_decl,int entering_scope)10158 tsubst_aggr_type (tree t,
10159 tree args,
10160 tsubst_flags_t complain,
10161 tree in_decl,
10162 int entering_scope)
10163 {
10164 if (t == NULL_TREE)
10165 return NULL_TREE;
10166
10167 switch (TREE_CODE (t))
10168 {
10169 case RECORD_TYPE:
10170 if (TYPE_PTRMEMFUNC_P (t))
10171 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
10172
10173 /* Else fall through. */
10174 case ENUMERAL_TYPE:
10175 case UNION_TYPE:
10176 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
10177 {
10178 tree argvec;
10179 tree context;
10180 tree r;
10181 int saved_unevaluated_operand;
10182 int saved_inhibit_evaluation_warnings;
10183
10184 /* In "sizeof(X<I>)" we need to evaluate "I". */
10185 saved_unevaluated_operand = cp_unevaluated_operand;
10186 cp_unevaluated_operand = 0;
10187 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
10188 c_inhibit_evaluation_warnings = 0;
10189
10190 /* First, determine the context for the type we are looking
10191 up. */
10192 context = TYPE_CONTEXT (t);
10193 if (context && TYPE_P (context))
10194 {
10195 context = tsubst_aggr_type (context, args, complain,
10196 in_decl, /*entering_scope=*/1);
10197 /* If context is a nested class inside a class template,
10198 it may still need to be instantiated (c++/33959). */
10199 context = complete_type (context);
10200 }
10201
10202 /* Then, figure out what arguments are appropriate for the
10203 type we are trying to find. For example, given:
10204
10205 template <class T> struct S;
10206 template <class T, class U> void f(T, U) { S<U> su; }
10207
10208 and supposing that we are instantiating f<int, double>,
10209 then our ARGS will be {int, double}, but, when looking up
10210 S we only want {double}. */
10211 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
10212 complain, in_decl);
10213 if (argvec == error_mark_node)
10214 r = error_mark_node;
10215 else
10216 {
10217 r = lookup_template_class (t, argvec, in_decl, context,
10218 entering_scope, complain);
10219 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
10220 }
10221
10222 cp_unevaluated_operand = saved_unevaluated_operand;
10223 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
10224
10225 return r;
10226 }
10227 else
10228 /* This is not a template type, so there's nothing to do. */
10229 return t;
10230
10231 default:
10232 return tsubst (t, args, complain, in_decl);
10233 }
10234 }
10235
10236 /* Substitute into the default argument ARG (a default argument for
10237 FN), which has the indicated TYPE. */
10238
10239 tree
tsubst_default_argument(tree fn,tree type,tree arg,tsubst_flags_t complain)10240 tsubst_default_argument (tree fn, tree type, tree arg, tsubst_flags_t complain)
10241 {
10242 tree saved_class_ptr = NULL_TREE;
10243 tree saved_class_ref = NULL_TREE;
10244 int errs = errorcount + sorrycount;
10245
10246 /* This can happen in invalid code. */
10247 if (TREE_CODE (arg) == DEFAULT_ARG)
10248 return arg;
10249
10250 /* This default argument came from a template. Instantiate the
10251 default argument here, not in tsubst. In the case of
10252 something like:
10253
10254 template <class T>
10255 struct S {
10256 static T t();
10257 void f(T = t());
10258 };
10259
10260 we must be careful to do name lookup in the scope of S<T>,
10261 rather than in the current class. */
10262 push_access_scope (fn);
10263 /* The "this" pointer is not valid in a default argument. */
10264 if (cfun)
10265 {
10266 saved_class_ptr = current_class_ptr;
10267 cp_function_chain->x_current_class_ptr = NULL_TREE;
10268 saved_class_ref = current_class_ref;
10269 cp_function_chain->x_current_class_ref = NULL_TREE;
10270 }
10271
10272 push_deferring_access_checks(dk_no_deferred);
10273 /* The default argument expression may cause implicitly defined
10274 member functions to be synthesized, which will result in garbage
10275 collection. We must treat this situation as if we were within
10276 the body of function so as to avoid collecting live data on the
10277 stack. */
10278 ++function_depth;
10279 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
10280 complain, NULL_TREE,
10281 /*integral_constant_expression_p=*/false);
10282 --function_depth;
10283 pop_deferring_access_checks();
10284
10285 /* Restore the "this" pointer. */
10286 if (cfun)
10287 {
10288 cp_function_chain->x_current_class_ptr = saved_class_ptr;
10289 cp_function_chain->x_current_class_ref = saved_class_ref;
10290 }
10291
10292 if (errorcount+sorrycount > errs
10293 && (complain & tf_warning_or_error))
10294 inform (input_location,
10295 " when instantiating default argument for call to %D", fn);
10296
10297 /* Make sure the default argument is reasonable. */
10298 arg = check_default_argument (type, arg, complain);
10299
10300 pop_access_scope (fn);
10301
10302 return arg;
10303 }
10304
10305 /* Substitute into all the default arguments for FN. */
10306
10307 static void
tsubst_default_arguments(tree fn,tsubst_flags_t complain)10308 tsubst_default_arguments (tree fn, tsubst_flags_t complain)
10309 {
10310 tree arg;
10311 tree tmpl_args;
10312
10313 tmpl_args = DECL_TI_ARGS (fn);
10314
10315 /* If this function is not yet instantiated, we certainly don't need
10316 its default arguments. */
10317 if (uses_template_parms (tmpl_args))
10318 return;
10319 /* Don't do this again for clones. */
10320 if (DECL_CLONED_FUNCTION_P (fn))
10321 return;
10322
10323 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
10324 arg;
10325 arg = TREE_CHAIN (arg))
10326 if (TREE_PURPOSE (arg))
10327 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
10328 TREE_VALUE (arg),
10329 TREE_PURPOSE (arg),
10330 complain);
10331 }
10332
10333 /* Substitute the ARGS into the T, which is a _DECL. Return the
10334 result of the substitution. Issue error and warning messages under
10335 control of COMPLAIN. */
10336
10337 static tree
tsubst_decl(tree t,tree args,tsubst_flags_t complain)10338 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
10339 {
10340 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10341 location_t saved_loc;
10342 tree r = NULL_TREE;
10343 tree in_decl = t;
10344 hashval_t hash = 0;
10345
10346 /* Set the filename and linenumber to improve error-reporting. */
10347 saved_loc = input_location;
10348 input_location = DECL_SOURCE_LOCATION (t);
10349
10350 switch (TREE_CODE (t))
10351 {
10352 case TEMPLATE_DECL:
10353 {
10354 /* We can get here when processing a member function template,
10355 member class template, or template template parameter. */
10356 tree decl = DECL_TEMPLATE_RESULT (t);
10357 tree spec;
10358 tree tmpl_args;
10359 tree full_args;
10360
10361 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10362 {
10363 /* Template template parameter is treated here. */
10364 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10365 if (new_type == error_mark_node)
10366 RETURN (error_mark_node);
10367 /* If we get a real template back, return it. This can happen in
10368 the context of most_specialized_class. */
10369 if (TREE_CODE (new_type) == TEMPLATE_DECL)
10370 return new_type;
10371
10372 r = copy_decl (t);
10373 DECL_CHAIN (r) = NULL_TREE;
10374 TREE_TYPE (r) = new_type;
10375 DECL_TEMPLATE_RESULT (r)
10376 = build_decl (DECL_SOURCE_LOCATION (decl),
10377 TYPE_DECL, DECL_NAME (decl), new_type);
10378 DECL_TEMPLATE_PARMS (r)
10379 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10380 complain);
10381 TYPE_NAME (new_type) = r;
10382 break;
10383 }
10384
10385 /* We might already have an instance of this template.
10386 The ARGS are for the surrounding class type, so the
10387 full args contain the tsubst'd args for the context,
10388 plus the innermost args from the template decl. */
10389 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10390 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10391 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10392 /* Because this is a template, the arguments will still be
10393 dependent, even after substitution. If
10394 PROCESSING_TEMPLATE_DECL is not set, the dependency
10395 predicates will short-circuit. */
10396 ++processing_template_decl;
10397 full_args = tsubst_template_args (tmpl_args, args,
10398 complain, in_decl);
10399 --processing_template_decl;
10400 if (full_args == error_mark_node)
10401 RETURN (error_mark_node);
10402
10403 /* If this is a default template template argument,
10404 tsubst might not have changed anything. */
10405 if (full_args == tmpl_args)
10406 RETURN (t);
10407
10408 hash = hash_tmpl_and_args (t, full_args);
10409 spec = retrieve_specialization (t, full_args, hash);
10410 if (spec != NULL_TREE)
10411 {
10412 r = spec;
10413 break;
10414 }
10415
10416 /* Make a new template decl. It will be similar to the
10417 original, but will record the current template arguments.
10418 We also create a new function declaration, which is just
10419 like the old one, but points to this new template, rather
10420 than the old one. */
10421 r = copy_decl (t);
10422 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10423 DECL_CHAIN (r) = NULL_TREE;
10424
10425 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10426
10427 if (TREE_CODE (decl) == TYPE_DECL
10428 && !TYPE_DECL_ALIAS_P (decl))
10429 {
10430 tree new_type;
10431 ++processing_template_decl;
10432 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10433 --processing_template_decl;
10434 if (new_type == error_mark_node)
10435 RETURN (error_mark_node);
10436
10437 TREE_TYPE (r) = new_type;
10438 /* For a partial specialization, we need to keep pointing to
10439 the primary template. */
10440 if (!DECL_TEMPLATE_SPECIALIZATION (t))
10441 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10442 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10443 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10444 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10445 }
10446 else
10447 {
10448 tree new_decl;
10449 ++processing_template_decl;
10450 new_decl = tsubst (decl, args, complain, in_decl);
10451 --processing_template_decl;
10452 if (new_decl == error_mark_node)
10453 RETURN (error_mark_node);
10454
10455 DECL_TEMPLATE_RESULT (r) = new_decl;
10456 DECL_TI_TEMPLATE (new_decl) = r;
10457 TREE_TYPE (r) = TREE_TYPE (new_decl);
10458 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10459 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10460 }
10461
10462 SET_DECL_IMPLICIT_INSTANTIATION (r);
10463 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10464 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10465
10466 /* The template parameters for this new template are all the
10467 template parameters for the old template, except the
10468 outermost level of parameters. */
10469 DECL_TEMPLATE_PARMS (r)
10470 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10471 complain);
10472
10473 if (PRIMARY_TEMPLATE_P (t))
10474 DECL_PRIMARY_TEMPLATE (r) = r;
10475
10476 if (TREE_CODE (decl) != TYPE_DECL)
10477 /* Record this non-type partial instantiation. */
10478 register_specialization (r, t,
10479 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10480 false, hash);
10481 }
10482 break;
10483
10484 case FUNCTION_DECL:
10485 {
10486 tree ctx;
10487 tree argvec = NULL_TREE;
10488 tree *friends;
10489 tree gen_tmpl;
10490 tree type;
10491 int member;
10492 int args_depth;
10493 int parms_depth;
10494
10495 /* Nobody should be tsubst'ing into non-template functions. */
10496 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10497
10498 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10499 {
10500 tree spec;
10501 bool dependent_p;
10502
10503 /* If T is not dependent, just return it. We have to
10504 increment PROCESSING_TEMPLATE_DECL because
10505 value_dependent_expression_p assumes that nothing is
10506 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10507 ++processing_template_decl;
10508 dependent_p = value_dependent_expression_p (t);
10509 --processing_template_decl;
10510 if (!dependent_p)
10511 RETURN (t);
10512
10513 /* Calculate the most general template of which R is a
10514 specialization, and the complete set of arguments used to
10515 specialize R. */
10516 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10517 argvec = tsubst_template_args (DECL_TI_ARGS
10518 (DECL_TEMPLATE_RESULT
10519 (DECL_TI_TEMPLATE (t))),
10520 args, complain, in_decl);
10521 if (argvec == error_mark_node)
10522 RETURN (error_mark_node);
10523
10524 /* Check to see if we already have this specialization. */
10525 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10526 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10527
10528 if (spec)
10529 {
10530 r = spec;
10531 break;
10532 }
10533
10534 /* We can see more levels of arguments than parameters if
10535 there was a specialization of a member template, like
10536 this:
10537
10538 template <class T> struct S { template <class U> void f(); }
10539 template <> template <class U> void S<int>::f(U);
10540
10541 Here, we'll be substituting into the specialization,
10542 because that's where we can find the code we actually
10543 want to generate, but we'll have enough arguments for
10544 the most general template.
10545
10546 We also deal with the peculiar case:
10547
10548 template <class T> struct S {
10549 template <class U> friend void f();
10550 };
10551 template <class U> void f() {}
10552 template S<int>;
10553 template void f<double>();
10554
10555 Here, the ARGS for the instantiation of will be {int,
10556 double}. But, we only need as many ARGS as there are
10557 levels of template parameters in CODE_PATTERN. We are
10558 careful not to get fooled into reducing the ARGS in
10559 situations like:
10560
10561 template <class T> struct S { template <class U> void f(U); }
10562 template <class T> template <> void S<T>::f(int) {}
10563
10564 which we can spot because the pattern will be a
10565 specialization in this case. */
10566 args_depth = TMPL_ARGS_DEPTH (args);
10567 parms_depth =
10568 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10569 if (args_depth > parms_depth
10570 && !DECL_TEMPLATE_SPECIALIZATION (t))
10571 args = get_innermost_template_args (args, parms_depth);
10572 }
10573 else
10574 {
10575 /* This special case arises when we have something like this:
10576
10577 template <class T> struct S {
10578 friend void f<int>(int, double);
10579 };
10580
10581 Here, the DECL_TI_TEMPLATE for the friend declaration
10582 will be an IDENTIFIER_NODE. We are being called from
10583 tsubst_friend_function, and we want only to create a
10584 new decl (R) with appropriate types so that we can call
10585 determine_specialization. */
10586 gen_tmpl = NULL_TREE;
10587 }
10588
10589 if (DECL_CLASS_SCOPE_P (t))
10590 {
10591 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10592 member = 2;
10593 else
10594 member = 1;
10595 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10596 complain, t, /*entering_scope=*/1);
10597 }
10598 else
10599 {
10600 member = 0;
10601 ctx = DECL_CONTEXT (t);
10602 }
10603 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10604 if (type == error_mark_node)
10605 RETURN (error_mark_node);
10606
10607 /* If we hit excessive deduction depth, the type is bogus even if
10608 it isn't error_mark_node, so don't build a decl. */
10609 if (excessive_deduction_depth)
10610 RETURN (error_mark_node);
10611
10612 /* We do NOT check for matching decls pushed separately at this
10613 point, as they may not represent instantiations of this
10614 template, and in any case are considered separate under the
10615 discrete model. */
10616 r = copy_decl (t);
10617 DECL_USE_TEMPLATE (r) = 0;
10618 TREE_TYPE (r) = type;
10619 /* Clear out the mangled name and RTL for the instantiation. */
10620 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10621 SET_DECL_RTL (r, NULL);
10622 /* Leave DECL_INITIAL set on deleted instantiations. */
10623 if (!DECL_DELETED_FN (r))
10624 DECL_INITIAL (r) = NULL_TREE;
10625 DECL_CONTEXT (r) = ctx;
10626
10627 /* OpenMP UDRs have the only argument a reference to the declared
10628 type. We want to diagnose if the declared type is a reference,
10629 which is invalid, but as references to references are usually
10630 quietly merged, diagnose it here. */
10631 if (DECL_OMP_DECLARE_REDUCTION_P (t))
10632 {
10633 tree argtype
10634 = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (t))));
10635 argtype = tsubst (argtype, args, complain, in_decl);
10636 if (TREE_CODE (argtype) == REFERENCE_TYPE)
10637 error_at (DECL_SOURCE_LOCATION (t),
10638 "reference type %qT in "
10639 "%<#pragma omp declare reduction%>", argtype);
10640 if (strchr (IDENTIFIER_POINTER (DECL_NAME (t)), '~') == NULL)
10641 DECL_NAME (r) = omp_reduction_id (ERROR_MARK, DECL_NAME (t),
10642 argtype);
10643 }
10644
10645 if (member && DECL_CONV_FN_P (r))
10646 /* Type-conversion operator. Reconstruct the name, in
10647 case it's the name of one of the template's parameters. */
10648 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10649
10650 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10651 complain, t);
10652 DECL_RESULT (r) = NULL_TREE;
10653
10654 TREE_STATIC (r) = 0;
10655 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10656 DECL_EXTERNAL (r) = 1;
10657 /* If this is an instantiation of a function with internal
10658 linkage, we already know what object file linkage will be
10659 assigned to the instantiation. */
10660 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10661 DECL_DEFER_OUTPUT (r) = 0;
10662 DECL_CHAIN (r) = NULL_TREE;
10663 DECL_PENDING_INLINE_INFO (r) = 0;
10664 DECL_PENDING_INLINE_P (r) = 0;
10665 DECL_SAVED_TREE (r) = NULL_TREE;
10666 DECL_STRUCT_FUNCTION (r) = NULL;
10667 TREE_USED (r) = 0;
10668 /* We'll re-clone as appropriate in instantiate_template. */
10669 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10670
10671 /* If we aren't complaining now, return on error before we register
10672 the specialization so that we'll complain eventually. */
10673 if ((complain & tf_error) == 0
10674 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10675 && !grok_op_properties (r, /*complain=*/false))
10676 RETURN (error_mark_node);
10677
10678 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10679 this in the special friend case mentioned above where
10680 GEN_TMPL is NULL. */
10681 if (gen_tmpl)
10682 {
10683 DECL_TEMPLATE_INFO (r)
10684 = build_template_info (gen_tmpl, argvec);
10685 SET_DECL_IMPLICIT_INSTANTIATION (r);
10686
10687 tree new_r
10688 = register_specialization (r, gen_tmpl, argvec, false, hash);
10689 if (new_r != r)
10690 /* We instantiated this while substituting into
10691 the type earlier (template/friend54.C). */
10692 RETURN (new_r);
10693
10694 if (!DECL_FRIEND_P (r))
10695 note_comdat_fn (r);
10696
10697 /* We're not supposed to instantiate default arguments
10698 until they are called, for a template. But, for a
10699 declaration like:
10700
10701 template <class T> void f ()
10702 { extern void g(int i = T()); }
10703
10704 we should do the substitution when the template is
10705 instantiated. We handle the member function case in
10706 instantiate_class_template since the default arguments
10707 might refer to other members of the class. */
10708 if (!member
10709 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10710 && !uses_template_parms (argvec))
10711 tsubst_default_arguments (r, complain);
10712 }
10713 else
10714 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10715
10716 /* Copy the list of befriending classes. */
10717 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10718 *friends;
10719 friends = &TREE_CHAIN (*friends))
10720 {
10721 *friends = copy_node (*friends);
10722 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10723 args, complain,
10724 in_decl);
10725 }
10726
10727 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10728 {
10729 maybe_retrofit_in_chrg (r);
10730 if (DECL_CONSTRUCTOR_P (r))
10731 grok_ctor_properties (ctx, r);
10732 if (DECL_INHERITED_CTOR_BASE (r))
10733 deduce_inheriting_ctor (r);
10734 /* If this is an instantiation of a member template, clone it.
10735 If it isn't, that'll be handled by
10736 clone_constructors_and_destructors. */
10737 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10738 clone_function_decl (r, /*update_method_vec_p=*/0);
10739 }
10740 else if ((complain & tf_error) != 0
10741 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10742 && !grok_op_properties (r, /*complain=*/true))
10743 RETURN (error_mark_node);
10744
10745 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10746 SET_DECL_FRIEND_CONTEXT (r,
10747 tsubst (DECL_FRIEND_CONTEXT (t),
10748 args, complain, in_decl));
10749
10750 /* Possibly limit visibility based on template args. */
10751 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10752 if (DECL_VISIBILITY_SPECIFIED (t))
10753 {
10754 DECL_VISIBILITY_SPECIFIED (r) = 0;
10755 DECL_ATTRIBUTES (r)
10756 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10757 }
10758 determine_visibility (r);
10759 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10760 && !processing_template_decl)
10761 defaulted_late_check (r);
10762
10763 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10764 args, complain, in_decl);
10765 }
10766 break;
10767
10768 case PARM_DECL:
10769 {
10770 tree type = NULL_TREE;
10771 int i, len = 1;
10772 tree expanded_types = NULL_TREE;
10773 tree prev_r = NULL_TREE;
10774 tree first_r = NULL_TREE;
10775
10776 if (DECL_PACK_P (t))
10777 {
10778 /* If there is a local specialization that isn't a
10779 parameter pack, it means that we're doing a "simple"
10780 substitution from inside tsubst_pack_expansion. Just
10781 return the local specialization (which will be a single
10782 parm). */
10783 tree spec = retrieve_local_specialization (t);
10784 if (spec
10785 && TREE_CODE (spec) == PARM_DECL
10786 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10787 RETURN (spec);
10788
10789 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10790 the parameters in this function parameter pack. */
10791 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10792 complain, in_decl);
10793 if (TREE_CODE (expanded_types) == TREE_VEC)
10794 {
10795 len = TREE_VEC_LENGTH (expanded_types);
10796
10797 /* Zero-length parameter packs are boring. Just substitute
10798 into the chain. */
10799 if (len == 0)
10800 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10801 TREE_CHAIN (t)));
10802 }
10803 else
10804 {
10805 /* All we did was update the type. Make a note of that. */
10806 type = expanded_types;
10807 expanded_types = NULL_TREE;
10808 }
10809 }
10810
10811 /* Loop through all of the parameters we'll build. When T is
10812 a function parameter pack, LEN is the number of expanded
10813 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10814 r = NULL_TREE;
10815 for (i = 0; i < len; ++i)
10816 {
10817 prev_r = r;
10818 r = copy_node (t);
10819 if (DECL_TEMPLATE_PARM_P (t))
10820 SET_DECL_TEMPLATE_PARM_P (r);
10821
10822 if (expanded_types)
10823 /* We're on the Ith parameter of the function parameter
10824 pack. */
10825 {
10826 /* Get the Ith type. */
10827 type = TREE_VEC_ELT (expanded_types, i);
10828
10829 /* Rename the parameter to include the index. */
10830 DECL_NAME (r)
10831 = make_ith_pack_parameter_name (DECL_NAME (r), i);
10832 }
10833 else if (!type)
10834 /* We're dealing with a normal parameter. */
10835 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10836
10837 type = type_decays_to (type);
10838 TREE_TYPE (r) = type;
10839 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10840
10841 if (DECL_INITIAL (r))
10842 {
10843 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10844 DECL_INITIAL (r) = TREE_TYPE (r);
10845 else
10846 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10847 complain, in_decl);
10848 }
10849
10850 DECL_CONTEXT (r) = NULL_TREE;
10851
10852 if (!DECL_TEMPLATE_PARM_P (r))
10853 DECL_ARG_TYPE (r) = type_passed_as (type);
10854
10855 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10856 args, complain, in_decl);
10857
10858 /* Keep track of the first new parameter we
10859 generate. That's what will be returned to the
10860 caller. */
10861 if (!first_r)
10862 first_r = r;
10863
10864 /* Build a proper chain of parameters when substituting
10865 into a function parameter pack. */
10866 if (prev_r)
10867 DECL_CHAIN (prev_r) = r;
10868 }
10869
10870 /* If cp_unevaluated_operand is set, we're just looking for a
10871 single dummy parameter, so don't keep going. */
10872 if (DECL_CHAIN (t) && !cp_unevaluated_operand)
10873 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10874 complain, DECL_CHAIN (t));
10875
10876 /* FIRST_R contains the start of the chain we've built. */
10877 r = first_r;
10878 }
10879 break;
10880
10881 case FIELD_DECL:
10882 {
10883 tree type = NULL_TREE;
10884 tree vec = NULL_TREE;
10885 tree expanded_types = NULL_TREE;
10886 int len = 1;
10887
10888 if (PACK_EXPANSION_P (TREE_TYPE (t)))
10889 {
10890 /* This field is a lambda capture pack. Return a TREE_VEC of
10891 the expanded fields to instantiate_class_template_1 and
10892 store them in the specializations hash table as a
10893 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
10894 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10895 complain, in_decl);
10896 if (TREE_CODE (expanded_types) == TREE_VEC)
10897 {
10898 len = TREE_VEC_LENGTH (expanded_types);
10899 vec = make_tree_vec (len);
10900 }
10901 else
10902 {
10903 /* All we did was update the type. Make a note of that. */
10904 type = expanded_types;
10905 expanded_types = NULL_TREE;
10906 }
10907 }
10908
10909 for (int i = 0; i < len; ++i)
10910 {
10911 r = copy_decl (t);
10912 if (expanded_types)
10913 {
10914 type = TREE_VEC_ELT (expanded_types, i);
10915 DECL_NAME (r)
10916 = make_ith_pack_parameter_name (DECL_NAME (r), i);
10917 }
10918 else if (!type)
10919 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10920
10921 if (type == error_mark_node)
10922 RETURN (error_mark_node);
10923 TREE_TYPE (r) = type;
10924 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10925
10926 if (DECL_C_BIT_FIELD (r))
10927 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10928 non-bit-fields DECL_INITIAL is a non-static data member
10929 initializer, which gets deferred instantiation. */
10930 DECL_INITIAL (r)
10931 = tsubst_expr (DECL_INITIAL (t), args,
10932 complain, in_decl,
10933 /*integral_constant_expression_p=*/true);
10934 else if (DECL_INITIAL (t))
10935 {
10936 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10937 NSDMI in perform_member_init. Still set DECL_INITIAL
10938 so that we know there is one. */
10939 DECL_INITIAL (r) = void_zero_node;
10940 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10941 retrofit_lang_decl (r);
10942 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10943 }
10944 /* We don't have to set DECL_CONTEXT here; it is set by
10945 finish_member_declaration. */
10946 DECL_CHAIN (r) = NULL_TREE;
10947
10948 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10949 args, complain, in_decl);
10950
10951 if (vec)
10952 TREE_VEC_ELT (vec, i) = r;
10953 }
10954
10955 if (vec)
10956 {
10957 r = vec;
10958 tree pack = make_node (NONTYPE_ARGUMENT_PACK);
10959 tree tpack = cxx_make_type (TYPE_ARGUMENT_PACK);
10960 SET_ARGUMENT_PACK_ARGS (pack, vec);
10961 SET_ARGUMENT_PACK_ARGS (tpack, expanded_types);
10962 TREE_TYPE (pack) = tpack;
10963 register_specialization (pack, t, args, false, 0);
10964 }
10965 }
10966 break;
10967
10968 case USING_DECL:
10969 /* We reach here only for member using decls. We also need to check
10970 uses_template_parms because DECL_DEPENDENT_P is not set for a
10971 using-declaration that designates a member of the current
10972 instantiation (c++/53549). */
10973 if (DECL_DEPENDENT_P (t)
10974 || uses_template_parms (USING_DECL_SCOPE (t)))
10975 {
10976 tree inst_scope = tsubst_copy (USING_DECL_SCOPE (t), args,
10977 complain, in_decl);
10978 tree name = tsubst_copy (DECL_NAME (t), args, complain, in_decl);
10979 r = do_class_using_decl (inst_scope, name);
10980 if (!r)
10981 r = error_mark_node;
10982 else
10983 {
10984 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10985 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10986 }
10987 }
10988 else
10989 {
10990 r = copy_node (t);
10991 DECL_CHAIN (r) = NULL_TREE;
10992 }
10993 break;
10994
10995 case TYPE_DECL:
10996 case VAR_DECL:
10997 {
10998 tree argvec = NULL_TREE;
10999 tree gen_tmpl = NULL_TREE;
11000 tree spec;
11001 tree tmpl = NULL_TREE;
11002 tree ctx;
11003 tree type = NULL_TREE;
11004 bool local_p;
11005
11006 if (TREE_TYPE (t) == error_mark_node)
11007 RETURN (error_mark_node);
11008
11009 if (TREE_CODE (t) == TYPE_DECL
11010 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
11011 {
11012 /* If this is the canonical decl, we don't have to
11013 mess with instantiations, and often we can't (for
11014 typename, template type parms and such). Note that
11015 TYPE_NAME is not correct for the above test if
11016 we've copied the type for a typedef. */
11017 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11018 if (type == error_mark_node)
11019 RETURN (error_mark_node);
11020 r = TYPE_NAME (type);
11021 break;
11022 }
11023
11024 /* Check to see if we already have the specialization we
11025 need. */
11026 spec = NULL_TREE;
11027 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
11028 {
11029 /* T is a static data member or namespace-scope entity.
11030 We have to substitute into namespace-scope variables
11031 (even though such entities are never templates) because
11032 of cases like:
11033
11034 template <class T> void f() { extern T t; }
11035
11036 where the entity referenced is not known until
11037 instantiation time. */
11038 local_p = false;
11039 ctx = DECL_CONTEXT (t);
11040 if (DECL_CLASS_SCOPE_P (t))
11041 {
11042 ctx = tsubst_aggr_type (ctx, args,
11043 complain,
11044 in_decl, /*entering_scope=*/1);
11045 /* If CTX is unchanged, then T is in fact the
11046 specialization we want. That situation occurs when
11047 referencing a static data member within in its own
11048 class. We can use pointer equality, rather than
11049 same_type_p, because DECL_CONTEXT is always
11050 canonical... */
11051 if (ctx == DECL_CONTEXT (t)
11052 && (TREE_CODE (t) != TYPE_DECL
11053 /* ... unless T is a member template; in which
11054 case our caller can be willing to create a
11055 specialization of that template represented
11056 by T. */
11057 || !(DECL_TI_TEMPLATE (t)
11058 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
11059 spec = t;
11060 }
11061
11062 if (!spec)
11063 {
11064 tmpl = DECL_TI_TEMPLATE (t);
11065 gen_tmpl = most_general_template (tmpl);
11066 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
11067 if (argvec == error_mark_node)
11068 RETURN (error_mark_node);
11069 hash = hash_tmpl_and_args (gen_tmpl, argvec);
11070 spec = retrieve_specialization (gen_tmpl, argvec, hash);
11071 }
11072 }
11073 else
11074 {
11075 /* A local variable. */
11076 local_p = true;
11077 /* Subsequent calls to pushdecl will fill this in. */
11078 ctx = NULL_TREE;
11079 spec = retrieve_local_specialization (t);
11080 }
11081 /* If we already have the specialization we need, there is
11082 nothing more to do. */
11083 if (spec)
11084 {
11085 r = spec;
11086 break;
11087 }
11088
11089 /* Create a new node for the specialization we need. */
11090 r = copy_decl (t);
11091 if (type == NULL_TREE)
11092 {
11093 if (is_typedef_decl (t))
11094 type = DECL_ORIGINAL_TYPE (t);
11095 else
11096 type = TREE_TYPE (t);
11097 if (VAR_P (t)
11098 && VAR_HAD_UNKNOWN_BOUND (t)
11099 && type != error_mark_node)
11100 type = strip_array_domain (type);
11101 type = tsubst (type, args, complain, in_decl);
11102 }
11103 if (VAR_P (r))
11104 {
11105 /* Even if the original location is out of scope, the
11106 newly substituted one is not. */
11107 DECL_DEAD_FOR_LOCAL (r) = 0;
11108 DECL_INITIALIZED_P (r) = 0;
11109 DECL_TEMPLATE_INSTANTIATED (r) = 0;
11110 if (type == error_mark_node)
11111 RETURN (error_mark_node);
11112 if (TREE_CODE (type) == FUNCTION_TYPE)
11113 {
11114 /* It may seem that this case cannot occur, since:
11115
11116 typedef void f();
11117 void g() { f x; }
11118
11119 declares a function, not a variable. However:
11120
11121 typedef void f();
11122 template <typename T> void g() { T t; }
11123 template void g<f>();
11124
11125 is an attempt to declare a variable with function
11126 type. */
11127 error ("variable %qD has function type",
11128 /* R is not yet sufficiently initialized, so we
11129 just use its name. */
11130 DECL_NAME (r));
11131 RETURN (error_mark_node);
11132 }
11133 type = complete_type (type);
11134 /* Wait until cp_finish_decl to set this again, to handle
11135 circular dependency (template/instantiate6.C). */
11136 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
11137 type = check_var_type (DECL_NAME (r), type);
11138
11139 if (DECL_HAS_VALUE_EXPR_P (t))
11140 {
11141 tree ve = DECL_VALUE_EXPR (t);
11142 ve = tsubst_expr (ve, args, complain, in_decl,
11143 /*constant_expression_p=*/false);
11144 if (REFERENCE_REF_P (ve))
11145 {
11146 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
11147 ve = TREE_OPERAND (ve, 0);
11148 }
11149 SET_DECL_VALUE_EXPR (r, ve);
11150 }
11151 }
11152 else if (DECL_SELF_REFERENCE_P (t))
11153 SET_DECL_SELF_REFERENCE_P (r);
11154 TREE_TYPE (r) = type;
11155 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
11156 DECL_CONTEXT (r) = ctx;
11157 /* Clear out the mangled name and RTL for the instantiation. */
11158 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
11159 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
11160 SET_DECL_RTL (r, NULL);
11161 /* The initializer must not be expanded until it is required;
11162 see [temp.inst]. */
11163 DECL_INITIAL (r) = NULL_TREE;
11164 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
11165 SET_DECL_RTL (r, NULL);
11166 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
11167 if (VAR_P (r))
11168 {
11169 /* Possibly limit visibility based on template args. */
11170 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
11171 if (DECL_VISIBILITY_SPECIFIED (t))
11172 {
11173 DECL_VISIBILITY_SPECIFIED (r) = 0;
11174 DECL_ATTRIBUTES (r)
11175 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
11176 }
11177 determine_visibility (r);
11178 }
11179
11180 if (!local_p)
11181 {
11182 /* A static data member declaration is always marked
11183 external when it is declared in-class, even if an
11184 initializer is present. We mimic the non-template
11185 processing here. */
11186 DECL_EXTERNAL (r) = 1;
11187
11188 register_specialization (r, gen_tmpl, argvec, false, hash);
11189 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
11190 SET_DECL_IMPLICIT_INSTANTIATION (r);
11191 }
11192 else if (!cp_unevaluated_operand)
11193 register_local_specialization (r, t);
11194
11195 DECL_CHAIN (r) = NULL_TREE;
11196
11197 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
11198 /*flags=*/0,
11199 args, complain, in_decl);
11200
11201 /* Preserve a typedef that names a type. */
11202 if (is_typedef_decl (r))
11203 {
11204 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
11205 set_underlying_type (r);
11206 }
11207
11208 layout_decl (r, 0);
11209 }
11210 break;
11211
11212 default:
11213 gcc_unreachable ();
11214 }
11215 #undef RETURN
11216
11217 out:
11218 /* Restore the file and line information. */
11219 input_location = saved_loc;
11220
11221 return r;
11222 }
11223
11224 /* Substitute into the ARG_TYPES of a function type.
11225 If END is a TREE_CHAIN, leave it and any following types
11226 un-substituted. */
11227
11228 static tree
tsubst_arg_types(tree arg_types,tree args,tree end,tsubst_flags_t complain,tree in_decl)11229 tsubst_arg_types (tree arg_types,
11230 tree args,
11231 tree end,
11232 tsubst_flags_t complain,
11233 tree in_decl)
11234 {
11235 tree remaining_arg_types;
11236 tree type = NULL_TREE;
11237 int i = 1;
11238 tree expanded_args = NULL_TREE;
11239 tree default_arg;
11240
11241 if (!arg_types || arg_types == void_list_node || arg_types == end)
11242 return arg_types;
11243
11244 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
11245 args, end, complain, in_decl);
11246 if (remaining_arg_types == error_mark_node)
11247 return error_mark_node;
11248
11249 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
11250 {
11251 /* For a pack expansion, perform substitution on the
11252 entire expression. Later on, we'll handle the arguments
11253 one-by-one. */
11254 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
11255 args, complain, in_decl);
11256
11257 if (TREE_CODE (expanded_args) == TREE_VEC)
11258 /* So that we'll spin through the parameters, one by one. */
11259 i = TREE_VEC_LENGTH (expanded_args);
11260 else
11261 {
11262 /* We only partially substituted into the parameter
11263 pack. Our type is TYPE_PACK_EXPANSION. */
11264 type = expanded_args;
11265 expanded_args = NULL_TREE;
11266 }
11267 }
11268
11269 while (i > 0) {
11270 --i;
11271
11272 if (expanded_args)
11273 type = TREE_VEC_ELT (expanded_args, i);
11274 else if (!type)
11275 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
11276
11277 if (type == error_mark_node)
11278 return error_mark_node;
11279 if (VOID_TYPE_P (type))
11280 {
11281 if (complain & tf_error)
11282 {
11283 error ("invalid parameter type %qT", type);
11284 if (in_decl)
11285 error ("in declaration %q+D", in_decl);
11286 }
11287 return error_mark_node;
11288 }
11289 /* DR 657. */
11290 if (abstract_virtuals_error_sfinae (ACU_PARM, type, complain))
11291 return error_mark_node;
11292
11293 /* Do array-to-pointer, function-to-pointer conversion, and ignore
11294 top-level qualifiers as required. */
11295 type = cv_unqualified (type_decays_to (type));
11296
11297 /* We do not substitute into default arguments here. The standard
11298 mandates that they be instantiated only when needed, which is
11299 done in build_over_call. */
11300 default_arg = TREE_PURPOSE (arg_types);
11301
11302 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
11303 {
11304 /* We've instantiated a template before its default arguments
11305 have been parsed. This can happen for a nested template
11306 class, and is not an error unless we require the default
11307 argument in a call of this function. */
11308 remaining_arg_types =
11309 tree_cons (default_arg, type, remaining_arg_types);
11310 vec_safe_push (DEFARG_INSTANTIATIONS(default_arg), remaining_arg_types);
11311 }
11312 else
11313 remaining_arg_types =
11314 hash_tree_cons (default_arg, type, remaining_arg_types);
11315 }
11316
11317 return remaining_arg_types;
11318 }
11319
11320 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
11321 *not* handle the exception-specification for FNTYPE, because the
11322 initial substitution of explicitly provided template parameters
11323 during argument deduction forbids substitution into the
11324 exception-specification:
11325
11326 [temp.deduct]
11327
11328 All references in the function type of the function template to the
11329 corresponding template parameters are replaced by the specified tem-
11330 plate argument values. If a substitution in a template parameter or
11331 in the function type of the function template results in an invalid
11332 type, type deduction fails. [Note: The equivalent substitution in
11333 exception specifications is done only when the function is instanti-
11334 ated, at which point a program is ill-formed if the substitution
11335 results in an invalid type.] */
11336
11337 static tree
tsubst_function_type(tree t,tree args,tsubst_flags_t complain,tree in_decl)11338 tsubst_function_type (tree t,
11339 tree args,
11340 tsubst_flags_t complain,
11341 tree in_decl)
11342 {
11343 tree return_type;
11344 tree arg_types;
11345 tree fntype;
11346
11347 /* The TYPE_CONTEXT is not used for function/method types. */
11348 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
11349
11350 /* Substitute the return type. */
11351 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11352 if (return_type == error_mark_node)
11353 return error_mark_node;
11354 /* DR 486 clarifies that creation of a function type with an
11355 invalid return type is a deduction failure. */
11356 if (TREE_CODE (return_type) == ARRAY_TYPE
11357 || TREE_CODE (return_type) == FUNCTION_TYPE)
11358 {
11359 if (complain & tf_error)
11360 {
11361 if (TREE_CODE (return_type) == ARRAY_TYPE)
11362 error ("function returning an array");
11363 else
11364 error ("function returning a function");
11365 }
11366 return error_mark_node;
11367 }
11368 /* And DR 657. */
11369 if (abstract_virtuals_error_sfinae (ACU_RETURN, return_type, complain))
11370 return error_mark_node;
11371
11372 /* Substitute the argument types. */
11373 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
11374 complain, in_decl);
11375 if (arg_types == error_mark_node)
11376 return error_mark_node;
11377
11378 /* Construct a new type node and return it. */
11379 if (TREE_CODE (t) == FUNCTION_TYPE)
11380 {
11381 fntype = build_function_type (return_type, arg_types);
11382 fntype = apply_memfn_quals (fntype,
11383 type_memfn_quals (t),
11384 type_memfn_rqual (t));
11385 }
11386 else
11387 {
11388 tree r = TREE_TYPE (TREE_VALUE (arg_types));
11389 /* Don't pick up extra function qualifiers from the basetype. */
11390 r = cp_build_qualified_type_real (r, type_memfn_quals (t), complain);
11391 if (! MAYBE_CLASS_TYPE_P (r))
11392 {
11393 /* [temp.deduct]
11394
11395 Type deduction may fail for any of the following
11396 reasons:
11397
11398 -- Attempting to create "pointer to member of T" when T
11399 is not a class type. */
11400 if (complain & tf_error)
11401 error ("creating pointer to member function of non-class type %qT",
11402 r);
11403 return error_mark_node;
11404 }
11405
11406 fntype = build_method_type_directly (r, return_type,
11407 TREE_CHAIN (arg_types));
11408 fntype = build_ref_qualified_type (fntype, type_memfn_rqual (t));
11409 }
11410 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
11411
11412 return fntype;
11413 }
11414
11415 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11416 ARGS into that specification, and return the substituted
11417 specification. If there is no specification, return NULL_TREE. */
11418
11419 static tree
tsubst_exception_specification(tree fntype,tree args,tsubst_flags_t complain,tree in_decl,bool defer_ok)11420 tsubst_exception_specification (tree fntype,
11421 tree args,
11422 tsubst_flags_t complain,
11423 tree in_decl,
11424 bool defer_ok)
11425 {
11426 tree specs;
11427 tree new_specs;
11428
11429 specs = TYPE_RAISES_EXCEPTIONS (fntype);
11430 new_specs = NULL_TREE;
11431 if (specs && TREE_PURPOSE (specs))
11432 {
11433 /* A noexcept-specifier. */
11434 tree expr = TREE_PURPOSE (specs);
11435 if (TREE_CODE (expr) == INTEGER_CST)
11436 new_specs = expr;
11437 else if (defer_ok)
11438 {
11439 /* Defer instantiation of noexcept-specifiers to avoid
11440 excessive instantiations (c++/49107). */
11441 new_specs = make_node (DEFERRED_NOEXCEPT);
11442 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11443 {
11444 /* We already partially instantiated this member template,
11445 so combine the new args with the old. */
11446 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11447 = DEFERRED_NOEXCEPT_PATTERN (expr);
11448 DEFERRED_NOEXCEPT_ARGS (new_specs)
11449 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11450 }
11451 else
11452 {
11453 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11454 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11455 }
11456 }
11457 else
11458 new_specs = tsubst_copy_and_build
11459 (expr, args, complain, in_decl, /*function_p=*/false,
11460 /*integral_constant_expression_p=*/true);
11461 new_specs = build_noexcept_spec (new_specs, complain);
11462 }
11463 else if (specs)
11464 {
11465 if (! TREE_VALUE (specs))
11466 new_specs = specs;
11467 else
11468 while (specs)
11469 {
11470 tree spec;
11471 int i, len = 1;
11472 tree expanded_specs = NULL_TREE;
11473
11474 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11475 {
11476 /* Expand the pack expansion type. */
11477 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11478 args, complain,
11479 in_decl);
11480
11481 if (expanded_specs == error_mark_node)
11482 return error_mark_node;
11483 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11484 len = TREE_VEC_LENGTH (expanded_specs);
11485 else
11486 {
11487 /* We're substituting into a member template, so
11488 we got a TYPE_PACK_EXPANSION back. Add that
11489 expansion and move on. */
11490 gcc_assert (TREE_CODE (expanded_specs)
11491 == TYPE_PACK_EXPANSION);
11492 new_specs = add_exception_specifier (new_specs,
11493 expanded_specs,
11494 complain);
11495 specs = TREE_CHAIN (specs);
11496 continue;
11497 }
11498 }
11499
11500 for (i = 0; i < len; ++i)
11501 {
11502 if (expanded_specs)
11503 spec = TREE_VEC_ELT (expanded_specs, i);
11504 else
11505 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11506 if (spec == error_mark_node)
11507 return spec;
11508 new_specs = add_exception_specifier (new_specs, spec,
11509 complain);
11510 }
11511
11512 specs = TREE_CHAIN (specs);
11513 }
11514 }
11515 return new_specs;
11516 }
11517
11518 /* Take the tree structure T and replace template parameters used
11519 therein with the argument vector ARGS. IN_DECL is an associated
11520 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11521 Issue error and warning messages under control of COMPLAIN. Note
11522 that we must be relatively non-tolerant of extensions here, in
11523 order to preserve conformance; if we allow substitutions that
11524 should not be allowed, we may allow argument deductions that should
11525 not succeed, and therefore report ambiguous overload situations
11526 where there are none. In theory, we could allow the substitution,
11527 but indicate that it should have failed, and allow our caller to
11528 make sure that the right thing happens, but we don't try to do this
11529 yet.
11530
11531 This function is used for dealing with types, decls and the like;
11532 for expressions, use tsubst_expr or tsubst_copy. */
11533
11534 tree
tsubst(tree t,tree args,tsubst_flags_t complain,tree in_decl)11535 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11536 {
11537 enum tree_code code;
11538 tree type, r = NULL_TREE;
11539
11540 if (t == NULL_TREE || t == error_mark_node
11541 || t == integer_type_node
11542 || t == void_type_node
11543 || t == char_type_node
11544 || t == unknown_type_node
11545 || TREE_CODE (t) == NAMESPACE_DECL
11546 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11547 return t;
11548
11549 if (DECL_P (t))
11550 return tsubst_decl (t, args, complain);
11551
11552 if (args == NULL_TREE)
11553 return t;
11554
11555 code = TREE_CODE (t);
11556
11557 if (code == IDENTIFIER_NODE)
11558 type = IDENTIFIER_TYPE_VALUE (t);
11559 else
11560 type = TREE_TYPE (t);
11561
11562 gcc_assert (type != unknown_type_node);
11563
11564 /* Reuse typedefs. We need to do this to handle dependent attributes,
11565 such as attribute aligned. */
11566 if (TYPE_P (t)
11567 && typedef_variant_p (t))
11568 {
11569 tree decl = TYPE_NAME (t);
11570
11571 if (alias_template_specialization_p (t))
11572 {
11573 /* DECL represents an alias template and we want to
11574 instantiate it. */
11575 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11576 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11577 r = instantiate_alias_template (tmpl, gen_args, complain);
11578 }
11579 else if (DECL_CLASS_SCOPE_P (decl)
11580 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11581 && uses_template_parms (DECL_CONTEXT (decl)))
11582 {
11583 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11584 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11585 r = retrieve_specialization (tmpl, gen_args, 0);
11586 }
11587 else if (DECL_FUNCTION_SCOPE_P (decl)
11588 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11589 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11590 r = retrieve_local_specialization (decl);
11591 else
11592 /* The typedef is from a non-template context. */
11593 return t;
11594
11595 if (r)
11596 {
11597 r = TREE_TYPE (r);
11598 r = cp_build_qualified_type_real
11599 (r, cp_type_quals (t) | cp_type_quals (r),
11600 complain | tf_ignore_bad_quals);
11601 return r;
11602 }
11603 else
11604 {
11605 /* We don't have an instantiation yet, so drop the typedef. */
11606 int quals = cp_type_quals (t);
11607 t = DECL_ORIGINAL_TYPE (decl);
11608 t = cp_build_qualified_type_real (t, quals,
11609 complain | tf_ignore_bad_quals);
11610 }
11611 }
11612
11613 if (type
11614 && code != TYPENAME_TYPE
11615 && code != TEMPLATE_TYPE_PARM
11616 && code != IDENTIFIER_NODE
11617 && code != FUNCTION_TYPE
11618 && code != METHOD_TYPE)
11619 type = tsubst (type, args, complain, in_decl);
11620 if (type == error_mark_node)
11621 return error_mark_node;
11622
11623 switch (code)
11624 {
11625 case RECORD_TYPE:
11626 case UNION_TYPE:
11627 case ENUMERAL_TYPE:
11628 return tsubst_aggr_type (t, args, complain, in_decl,
11629 /*entering_scope=*/0);
11630
11631 case ERROR_MARK:
11632 case IDENTIFIER_NODE:
11633 case VOID_TYPE:
11634 case REAL_TYPE:
11635 case COMPLEX_TYPE:
11636 case VECTOR_TYPE:
11637 case BOOLEAN_TYPE:
11638 case NULLPTR_TYPE:
11639 case LANG_TYPE:
11640 return t;
11641
11642 case INTEGER_TYPE:
11643 if (t == integer_type_node)
11644 return t;
11645
11646 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11647 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11648 return t;
11649
11650 {
11651 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11652
11653 max = tsubst_expr (omax, args, complain, in_decl,
11654 /*integral_constant_expression_p=*/false);
11655
11656 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11657 needed. */
11658 if (TREE_CODE (max) == NOP_EXPR
11659 && TREE_SIDE_EFFECTS (omax)
11660 && !TREE_TYPE (max))
11661 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11662
11663 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11664 with TREE_SIDE_EFFECTS that indicates this is not an integral
11665 constant expression. */
11666 if (processing_template_decl
11667 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11668 {
11669 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11670 TREE_SIDE_EFFECTS (max) = 1;
11671 }
11672
11673 return compute_array_index_type (NULL_TREE, max, complain);
11674 }
11675
11676 case TEMPLATE_TYPE_PARM:
11677 case TEMPLATE_TEMPLATE_PARM:
11678 case BOUND_TEMPLATE_TEMPLATE_PARM:
11679 case TEMPLATE_PARM_INDEX:
11680 {
11681 int idx;
11682 int level;
11683 int levels;
11684 tree arg = NULL_TREE;
11685
11686 r = NULL_TREE;
11687
11688 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11689 template_parm_level_and_index (t, &level, &idx);
11690
11691 levels = TMPL_ARGS_DEPTH (args);
11692 if (level <= levels)
11693 {
11694 arg = TMPL_ARG (args, level, idx);
11695
11696 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11697 {
11698 /* See through ARGUMENT_PACK_SELECT arguments. */
11699 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11700 /* If the selected argument is an expansion E, that most
11701 likely means we were called from
11702 gen_elem_of_pack_expansion_instantiation during the
11703 substituting of pack an argument pack (which Ith
11704 element is a pack expansion, where I is
11705 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
11706 In this case, the Ith element resulting from this
11707 substituting is going to be a pack expansion, which
11708 pattern is the pattern of E. Let's return the
11709 pattern of E, and
11710 gen_elem_of_pack_expansion_instantiation will
11711 build the resulting pack expansion from it. */
11712 if (PACK_EXPANSION_P (arg))
11713 arg = PACK_EXPANSION_PATTERN (arg);
11714 }
11715 }
11716
11717 if (arg == error_mark_node)
11718 return error_mark_node;
11719 else if (arg != NULL_TREE)
11720 {
11721 if (ARGUMENT_PACK_P (arg))
11722 /* If ARG is an argument pack, we don't actually want to
11723 perform a substitution here, because substitutions
11724 for argument packs are only done
11725 element-by-element. We can get to this point when
11726 substituting the type of a non-type template
11727 parameter pack, when that type actually contains
11728 template parameter packs from an outer template, e.g.,
11729
11730 template<typename... Types> struct A {
11731 template<Types... Values> struct B { };
11732 }; */
11733 return t;
11734
11735 if (code == TEMPLATE_TYPE_PARM)
11736 {
11737 int quals;
11738 gcc_assert (TYPE_P (arg));
11739
11740 quals = cp_type_quals (arg) | cp_type_quals (t);
11741
11742 return cp_build_qualified_type_real
11743 (arg, quals, complain | tf_ignore_bad_quals);
11744 }
11745 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11746 {
11747 /* We are processing a type constructed from a
11748 template template parameter. */
11749 tree argvec = tsubst (TYPE_TI_ARGS (t),
11750 args, complain, in_decl);
11751 if (argvec == error_mark_node)
11752 return error_mark_node;
11753
11754 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11755 || TREE_CODE (arg) == TEMPLATE_DECL
11756 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11757
11758 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11759 /* Consider this code:
11760
11761 template <template <class> class Template>
11762 struct Internal {
11763 template <class Arg> using Bind = Template<Arg>;
11764 };
11765
11766 template <template <class> class Template, class Arg>
11767 using Instantiate = Template<Arg>; //#0
11768
11769 template <template <class> class Template,
11770 class Argument>
11771 using Bind =
11772 Instantiate<Internal<Template>::template Bind,
11773 Argument>; //#1
11774
11775 When #1 is parsed, the
11776 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11777 parameter `Template' in #0 matches the
11778 UNBOUND_CLASS_TEMPLATE representing the argument
11779 `Internal<Template>::template Bind'; We then want
11780 to assemble the type `Bind<Argument>' that can't
11781 be fully created right now, because
11782 `Internal<Template>' not being complete, the Bind
11783 template cannot be looked up in that context. So
11784 we need to "store" `Bind<Argument>' for later
11785 when the context of Bind becomes complete. Let's
11786 store that in a TYPENAME_TYPE. */
11787 return make_typename_type (TYPE_CONTEXT (arg),
11788 build_nt (TEMPLATE_ID_EXPR,
11789 TYPE_IDENTIFIER (arg),
11790 argvec),
11791 typename_type,
11792 complain);
11793
11794 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11795 are resolving nested-types in the signature of a
11796 member function templates. Otherwise ARG is a
11797 TEMPLATE_DECL and is the real template to be
11798 instantiated. */
11799 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11800 arg = TYPE_NAME (arg);
11801
11802 r = lookup_template_class (arg,
11803 argvec, in_decl,
11804 DECL_CONTEXT (arg),
11805 /*entering_scope=*/0,
11806 complain);
11807 return cp_build_qualified_type_real
11808 (r, cp_type_quals (t) | cp_type_quals (r), complain);
11809 }
11810 else
11811 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11812 return convert_from_reference (unshare_expr (arg));
11813 }
11814
11815 if (level == 1)
11816 /* This can happen during the attempted tsubst'ing in
11817 unify. This means that we don't yet have any information
11818 about the template parameter in question. */
11819 return t;
11820
11821 /* Early in template argument deduction substitution, we don't
11822 want to reduce the level of 'auto', or it will be confused
11823 with a normal template parm in subsequent deduction. */
11824 if (is_auto (t) && (complain & tf_partial))
11825 return t;
11826
11827 /* If we get here, we must have been looking at a parm for a
11828 more deeply nested template. Make a new version of this
11829 template parameter, but with a lower level. */
11830 switch (code)
11831 {
11832 case TEMPLATE_TYPE_PARM:
11833 case TEMPLATE_TEMPLATE_PARM:
11834 case BOUND_TEMPLATE_TEMPLATE_PARM:
11835 if (cp_type_quals (t))
11836 {
11837 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11838 r = cp_build_qualified_type_real
11839 (r, cp_type_quals (t),
11840 complain | (code == TEMPLATE_TYPE_PARM
11841 ? tf_ignore_bad_quals : 0));
11842 }
11843 else
11844 {
11845 r = copy_type (t);
11846 TEMPLATE_TYPE_PARM_INDEX (r)
11847 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11848 r, levels, args, complain);
11849 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11850 TYPE_MAIN_VARIANT (r) = r;
11851 TYPE_POINTER_TO (r) = NULL_TREE;
11852 TYPE_REFERENCE_TO (r) = NULL_TREE;
11853
11854 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11855 /* We have reduced the level of the template
11856 template parameter, but not the levels of its
11857 template parameters, so canonical_type_parameter
11858 will not be able to find the canonical template
11859 template parameter for this level. Thus, we
11860 require structural equality checking to compare
11861 TEMPLATE_TEMPLATE_PARMs. */
11862 SET_TYPE_STRUCTURAL_EQUALITY (r);
11863 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11864 SET_TYPE_STRUCTURAL_EQUALITY (r);
11865 else
11866 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11867
11868 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11869 {
11870 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11871 complain, in_decl);
11872 if (argvec == error_mark_node)
11873 return error_mark_node;
11874
11875 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11876 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11877 }
11878 }
11879 break;
11880
11881 case TEMPLATE_PARM_INDEX:
11882 r = reduce_template_parm_level (t, type, levels, args, complain);
11883 break;
11884
11885 default:
11886 gcc_unreachable ();
11887 }
11888
11889 return r;
11890 }
11891
11892 case TREE_LIST:
11893 {
11894 tree purpose, value, chain;
11895
11896 if (t == void_list_node)
11897 return t;
11898
11899 purpose = TREE_PURPOSE (t);
11900 if (purpose)
11901 {
11902 purpose = tsubst (purpose, args, complain, in_decl);
11903 if (purpose == error_mark_node)
11904 return error_mark_node;
11905 }
11906 value = TREE_VALUE (t);
11907 if (value)
11908 {
11909 value = tsubst (value, args, complain, in_decl);
11910 if (value == error_mark_node)
11911 return error_mark_node;
11912 }
11913 chain = TREE_CHAIN (t);
11914 if (chain && chain != void_type_node)
11915 {
11916 chain = tsubst (chain, args, complain, in_decl);
11917 if (chain == error_mark_node)
11918 return error_mark_node;
11919 }
11920 if (purpose == TREE_PURPOSE (t)
11921 && value == TREE_VALUE (t)
11922 && chain == TREE_CHAIN (t))
11923 return t;
11924 return hash_tree_cons (purpose, value, chain);
11925 }
11926
11927 case TREE_BINFO:
11928 /* We should never be tsubsting a binfo. */
11929 gcc_unreachable ();
11930
11931 case TREE_VEC:
11932 /* A vector of template arguments. */
11933 gcc_assert (!type);
11934 return tsubst_template_args (t, args, complain, in_decl);
11935
11936 case POINTER_TYPE:
11937 case REFERENCE_TYPE:
11938 {
11939 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11940 return t;
11941
11942 /* [temp.deduct]
11943
11944 Type deduction may fail for any of the following
11945 reasons:
11946
11947 -- Attempting to create a pointer to reference type.
11948 -- Attempting to create a reference to a reference type or
11949 a reference to void.
11950
11951 Core issue 106 says that creating a reference to a reference
11952 during instantiation is no longer a cause for failure. We
11953 only enforce this check in strict C++98 mode. */
11954 if ((TREE_CODE (type) == REFERENCE_TYPE
11955 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11956 || (code == REFERENCE_TYPE && VOID_TYPE_P (type)))
11957 {
11958 static location_t last_loc;
11959
11960 /* We keep track of the last time we issued this error
11961 message to avoid spewing a ton of messages during a
11962 single bad template instantiation. */
11963 if (complain & tf_error
11964 && last_loc != input_location)
11965 {
11966 if (VOID_TYPE_P (type))
11967 error ("forming reference to void");
11968 else if (code == POINTER_TYPE)
11969 error ("forming pointer to reference type %qT", type);
11970 else
11971 error ("forming reference to reference type %qT", type);
11972 last_loc = input_location;
11973 }
11974
11975 return error_mark_node;
11976 }
11977 else if (TREE_CODE (type) == FUNCTION_TYPE
11978 && (type_memfn_quals (type) != TYPE_UNQUALIFIED
11979 || type_memfn_rqual (type) != REF_QUAL_NONE))
11980 {
11981 if (complain & tf_error)
11982 {
11983 if (code == POINTER_TYPE)
11984 error ("forming pointer to qualified function type %qT",
11985 type);
11986 else
11987 error ("forming reference to qualified function type %qT",
11988 type);
11989 }
11990 return error_mark_node;
11991 }
11992 else if (code == POINTER_TYPE)
11993 {
11994 r = build_pointer_type (type);
11995 if (TREE_CODE (type) == METHOD_TYPE)
11996 r = build_ptrmemfunc_type (r);
11997 }
11998 else if (TREE_CODE (type) == REFERENCE_TYPE)
11999 /* In C++0x, during template argument substitution, when there is an
12000 attempt to create a reference to a reference type, reference
12001 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
12002
12003 "If a template-argument for a template-parameter T names a type
12004 that is a reference to a type A, an attempt to create the type
12005 'lvalue reference to cv T' creates the type 'lvalue reference to
12006 A,' while an attempt to create the type type rvalue reference to
12007 cv T' creates the type T"
12008 */
12009 r = cp_build_reference_type
12010 (TREE_TYPE (type),
12011 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
12012 else
12013 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
12014 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
12015
12016 if (cxx_dialect >= cxx1y
12017 && !(TREE_CODE (t) == REFERENCE_TYPE && REFERENCE_VLA_OK (t))
12018 && array_of_runtime_bound_p (type)
12019 && (flag_iso || warn_vla > 0))
12020 {
12021 if (complain & tf_warning_or_error)
12022 pedwarn
12023 (input_location, OPT_Wvla,
12024 code == REFERENCE_TYPE
12025 ? G_("cannot declare reference to array of runtime bound")
12026 : G_("cannot declare pointer to array of runtime bound"));
12027 else
12028 r = error_mark_node;
12029 }
12030
12031 if (r != error_mark_node)
12032 /* Will this ever be needed for TYPE_..._TO values? */
12033 layout_type (r);
12034
12035 return r;
12036 }
12037 case OFFSET_TYPE:
12038 {
12039 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
12040 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
12041 {
12042 /* [temp.deduct]
12043
12044 Type deduction may fail for any of the following
12045 reasons:
12046
12047 -- Attempting to create "pointer to member of T" when T
12048 is not a class type. */
12049 if (complain & tf_error)
12050 error ("creating pointer to member of non-class type %qT", r);
12051 return error_mark_node;
12052 }
12053 if (TREE_CODE (type) == REFERENCE_TYPE)
12054 {
12055 if (complain & tf_error)
12056 error ("creating pointer to member reference type %qT", type);
12057 return error_mark_node;
12058 }
12059 if (VOID_TYPE_P (type))
12060 {
12061 if (complain & tf_error)
12062 error ("creating pointer to member of type void");
12063 return error_mark_node;
12064 }
12065 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
12066 if (TREE_CODE (type) == FUNCTION_TYPE)
12067 {
12068 /* The type of the implicit object parameter gets its
12069 cv-qualifiers from the FUNCTION_TYPE. */
12070 tree memptr;
12071 tree method_type
12072 = build_memfn_type (type, r, type_memfn_quals (type),
12073 type_memfn_rqual (type));
12074 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
12075 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
12076 complain);
12077 }
12078 else
12079 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
12080 cp_type_quals (t),
12081 complain);
12082 }
12083 case FUNCTION_TYPE:
12084 case METHOD_TYPE:
12085 {
12086 tree fntype;
12087 tree specs;
12088 fntype = tsubst_function_type (t, args, complain, in_decl);
12089 if (fntype == error_mark_node)
12090 return error_mark_node;
12091
12092 /* Substitute the exception specification. */
12093 specs = tsubst_exception_specification (t, args, complain,
12094 in_decl, /*defer_ok*/true);
12095 if (specs == error_mark_node)
12096 return error_mark_node;
12097 if (specs)
12098 fntype = build_exception_variant (fntype, specs);
12099 return fntype;
12100 }
12101 case ARRAY_TYPE:
12102 {
12103 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
12104 if (domain == error_mark_node)
12105 return error_mark_node;
12106
12107 /* As an optimization, we avoid regenerating the array type if
12108 it will obviously be the same as T. */
12109 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
12110 return t;
12111
12112 /* These checks should match the ones in grokdeclarator.
12113
12114 [temp.deduct]
12115
12116 The deduction may fail for any of the following reasons:
12117
12118 -- Attempting to create an array with an element type that
12119 is void, a function type, or a reference type, or [DR337]
12120 an abstract class type. */
12121 if (VOID_TYPE_P (type)
12122 || TREE_CODE (type) == FUNCTION_TYPE
12123 || TREE_CODE (type) == REFERENCE_TYPE)
12124 {
12125 if (complain & tf_error)
12126 error ("creating array of %qT", type);
12127 return error_mark_node;
12128 }
12129
12130 if (abstract_virtuals_error_sfinae (ACU_ARRAY, type, complain))
12131 return error_mark_node;
12132
12133 r = build_cplus_array_type (type, domain);
12134
12135 if (TYPE_USER_ALIGN (t))
12136 {
12137 TYPE_ALIGN (r) = TYPE_ALIGN (t);
12138 TYPE_USER_ALIGN (r) = 1;
12139 }
12140
12141 return r;
12142 }
12143
12144 case TYPENAME_TYPE:
12145 {
12146 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
12147 in_decl, /*entering_scope=*/1);
12148 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
12149 complain, in_decl);
12150
12151 if (ctx == error_mark_node || f == error_mark_node)
12152 return error_mark_node;
12153
12154 if (!MAYBE_CLASS_TYPE_P (ctx))
12155 {
12156 if (complain & tf_error)
12157 error ("%qT is not a class, struct, or union type", ctx);
12158 return error_mark_node;
12159 }
12160 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
12161 {
12162 /* Normally, make_typename_type does not require that the CTX
12163 have complete type in order to allow things like:
12164
12165 template <class T> struct S { typename S<T>::X Y; };
12166
12167 But, such constructs have already been resolved by this
12168 point, so here CTX really should have complete type, unless
12169 it's a partial instantiation. */
12170 ctx = complete_type (ctx);
12171 if (!COMPLETE_TYPE_P (ctx))
12172 {
12173 if (complain & tf_error)
12174 cxx_incomplete_type_error (NULL_TREE, ctx);
12175 return error_mark_node;
12176 }
12177 }
12178
12179 f = make_typename_type (ctx, f, typename_type,
12180 complain | tf_keep_type_decl);
12181 if (f == error_mark_node)
12182 return f;
12183 if (TREE_CODE (f) == TYPE_DECL)
12184 {
12185 complain |= tf_ignore_bad_quals;
12186 f = TREE_TYPE (f);
12187 }
12188
12189 if (TREE_CODE (f) != TYPENAME_TYPE)
12190 {
12191 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
12192 {
12193 if (complain & tf_error)
12194 error ("%qT resolves to %qT, which is not an enumeration type",
12195 t, f);
12196 else
12197 return error_mark_node;
12198 }
12199 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
12200 {
12201 if (complain & tf_error)
12202 error ("%qT resolves to %qT, which is is not a class type",
12203 t, f);
12204 else
12205 return error_mark_node;
12206 }
12207 }
12208
12209 return cp_build_qualified_type_real
12210 (f, cp_type_quals (f) | cp_type_quals (t), complain);
12211 }
12212
12213 case UNBOUND_CLASS_TEMPLATE:
12214 {
12215 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
12216 in_decl, /*entering_scope=*/1);
12217 tree name = TYPE_IDENTIFIER (t);
12218 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
12219
12220 if (ctx == error_mark_node || name == error_mark_node)
12221 return error_mark_node;
12222
12223 if (parm_list)
12224 parm_list = tsubst_template_parms (parm_list, args, complain);
12225 return make_unbound_class_template (ctx, name, parm_list, complain);
12226 }
12227
12228 case TYPEOF_TYPE:
12229 {
12230 tree type;
12231
12232 ++cp_unevaluated_operand;
12233 ++c_inhibit_evaluation_warnings;
12234
12235 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
12236 complain, in_decl,
12237 /*integral_constant_expression_p=*/false);
12238
12239 --cp_unevaluated_operand;
12240 --c_inhibit_evaluation_warnings;
12241
12242 type = finish_typeof (type);
12243 return cp_build_qualified_type_real (type,
12244 cp_type_quals (t)
12245 | cp_type_quals (type),
12246 complain);
12247 }
12248
12249 case DECLTYPE_TYPE:
12250 {
12251 tree type;
12252
12253 ++cp_unevaluated_operand;
12254 ++c_inhibit_evaluation_warnings;
12255
12256 type = tsubst_copy_and_build (DECLTYPE_TYPE_EXPR (t), args,
12257 complain|tf_decltype, in_decl,
12258 /*function_p*/false,
12259 /*integral_constant_expression*/false);
12260
12261 --cp_unevaluated_operand;
12262 --c_inhibit_evaluation_warnings;
12263
12264 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
12265 type = lambda_capture_field_type (type,
12266 DECLTYPE_FOR_INIT_CAPTURE (t));
12267 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
12268 type = lambda_proxy_type (type);
12269 else
12270 {
12271 bool id = DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t);
12272 if (id && TREE_CODE (DECLTYPE_TYPE_EXPR (t)) == BIT_NOT_EXPR
12273 && EXPR_P (type))
12274 /* In a template ~id could be either a complement expression
12275 or an unqualified-id naming a destructor; if instantiating
12276 it produces an expression, it's not an id-expression or
12277 member access. */
12278 id = false;
12279 type = finish_decltype_type (type, id, complain);
12280 }
12281 return cp_build_qualified_type_real (type,
12282 cp_type_quals (t)
12283 | cp_type_quals (type),
12284 complain);
12285 }
12286
12287 case UNDERLYING_TYPE:
12288 {
12289 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
12290 complain, in_decl);
12291 return finish_underlying_type (type);
12292 }
12293
12294 case TYPE_ARGUMENT_PACK:
12295 case NONTYPE_ARGUMENT_PACK:
12296 {
12297 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
12298 tree packed_out =
12299 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
12300 args,
12301 complain,
12302 in_decl);
12303 SET_ARGUMENT_PACK_ARGS (r, packed_out);
12304
12305 /* For template nontype argument packs, also substitute into
12306 the type. */
12307 if (code == NONTYPE_ARGUMENT_PACK)
12308 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
12309
12310 return r;
12311 }
12312 break;
12313
12314 case INTEGER_CST:
12315 case REAL_CST:
12316 case STRING_CST:
12317 case PLUS_EXPR:
12318 case MINUS_EXPR:
12319 case NEGATE_EXPR:
12320 case NOP_EXPR:
12321 case INDIRECT_REF:
12322 case ADDR_EXPR:
12323 case CALL_EXPR:
12324 case ARRAY_REF:
12325 case SCOPE_REF:
12326 /* We should use one of the expression tsubsts for these codes. */
12327 gcc_unreachable ();
12328
12329 default:
12330 sorry ("use of %qs in template", get_tree_code_name (code));
12331 return error_mark_node;
12332 }
12333 }
12334
12335 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
12336 type of the expression on the left-hand side of the "." or "->"
12337 operator. */
12338
12339 static tree
tsubst_baselink(tree baselink,tree object_type,tree args,tsubst_flags_t complain,tree in_decl)12340 tsubst_baselink (tree baselink, tree object_type,
12341 tree args, tsubst_flags_t complain, tree in_decl)
12342 {
12343 tree name;
12344 tree qualifying_scope;
12345 tree fns;
12346 tree optype;
12347 tree template_args = 0;
12348 bool template_id_p = false;
12349 bool qualified = BASELINK_QUALIFIED_P (baselink);
12350
12351 /* A baselink indicates a function from a base class. Both the
12352 BASELINK_ACCESS_BINFO and the base class referenced may
12353 indicate bases of the template class, rather than the
12354 instantiated class. In addition, lookups that were not
12355 ambiguous before may be ambiguous now. Therefore, we perform
12356 the lookup again. */
12357 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
12358 qualifying_scope = tsubst (qualifying_scope, args,
12359 complain, in_decl);
12360 fns = BASELINK_FUNCTIONS (baselink);
12361 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
12362 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
12363 {
12364 template_id_p = true;
12365 template_args = TREE_OPERAND (fns, 1);
12366 fns = TREE_OPERAND (fns, 0);
12367 if (template_args)
12368 template_args = tsubst_template_args (template_args, args,
12369 complain, in_decl);
12370 }
12371 name = DECL_NAME (get_first_fn (fns));
12372 if (IDENTIFIER_TYPENAME_P (name))
12373 name = mangle_conv_op_name_for_type (optype);
12374 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
12375 if (!baselink)
12376 return error_mark_node;
12377
12378 /* If lookup found a single function, mark it as used at this
12379 point. (If it lookup found multiple functions the one selected
12380 later by overload resolution will be marked as used at that
12381 point.) */
12382 if (BASELINK_P (baselink))
12383 fns = BASELINK_FUNCTIONS (baselink);
12384 if (!template_id_p && !really_overloaded_fn (fns))
12385 mark_used (OVL_CURRENT (fns));
12386
12387 /* Add back the template arguments, if present. */
12388 if (BASELINK_P (baselink) && template_id_p)
12389 BASELINK_FUNCTIONS (baselink)
12390 = build_nt (TEMPLATE_ID_EXPR,
12391 BASELINK_FUNCTIONS (baselink),
12392 template_args);
12393 /* Update the conversion operator type. */
12394 BASELINK_OPTYPE (baselink) = optype;
12395
12396 if (!object_type)
12397 object_type = current_class_type;
12398
12399 if (qualified)
12400 baselink = adjust_result_of_qualified_name_lookup (baselink,
12401 qualifying_scope,
12402 object_type);
12403 return baselink;
12404 }
12405
12406 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
12407 true if the qualified-id will be a postfix-expression in-and-of
12408 itself; false if more of the postfix-expression follows the
12409 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
12410 of "&". */
12411
12412 static tree
tsubst_qualified_id(tree qualified_id,tree args,tsubst_flags_t complain,tree in_decl,bool done,bool address_p)12413 tsubst_qualified_id (tree qualified_id, tree args,
12414 tsubst_flags_t complain, tree in_decl,
12415 bool done, bool address_p)
12416 {
12417 tree expr;
12418 tree scope;
12419 tree name;
12420 bool is_template;
12421 tree template_args;
12422 location_t loc = UNKNOWN_LOCATION;
12423
12424 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
12425
12426 /* Figure out what name to look up. */
12427 name = TREE_OPERAND (qualified_id, 1);
12428 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
12429 {
12430 is_template = true;
12431 loc = EXPR_LOCATION (name);
12432 template_args = TREE_OPERAND (name, 1);
12433 if (template_args)
12434 template_args = tsubst_template_args (template_args, args,
12435 complain, in_decl);
12436 name = TREE_OPERAND (name, 0);
12437 }
12438 else
12439 {
12440 is_template = false;
12441 template_args = NULL_TREE;
12442 }
12443
12444 /* Substitute into the qualifying scope. When there are no ARGS, we
12445 are just trying to simplify a non-dependent expression. In that
12446 case the qualifying scope may be dependent, and, in any case,
12447 substituting will not help. */
12448 scope = TREE_OPERAND (qualified_id, 0);
12449 if (args)
12450 {
12451 scope = tsubst (scope, args, complain, in_decl);
12452 expr = tsubst_copy (name, args, complain, in_decl);
12453 }
12454 else
12455 expr = name;
12456
12457 if (dependent_scope_p (scope))
12458 {
12459 if (is_template)
12460 expr = build_min_nt_loc (loc, TEMPLATE_ID_EXPR, expr, template_args);
12461 return build_qualified_name (NULL_TREE, scope, expr,
12462 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
12463 }
12464
12465 if (!BASELINK_P (name) && !DECL_P (expr))
12466 {
12467 if (TREE_CODE (expr) == BIT_NOT_EXPR)
12468 {
12469 /* A BIT_NOT_EXPR is used to represent a destructor. */
12470 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
12471 {
12472 error ("qualifying type %qT does not match destructor name ~%qT",
12473 scope, TREE_OPERAND (expr, 0));
12474 expr = error_mark_node;
12475 }
12476 else
12477 expr = lookup_qualified_name (scope, complete_dtor_identifier,
12478 /*is_type_p=*/0, false);
12479 }
12480 else
12481 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
12482 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
12483 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
12484 {
12485 if (complain & tf_error)
12486 {
12487 error ("dependent-name %qE is parsed as a non-type, but "
12488 "instantiation yields a type", qualified_id);
12489 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
12490 }
12491 return error_mark_node;
12492 }
12493 }
12494
12495 if (DECL_P (expr))
12496 {
12497 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
12498 scope);
12499 /* Remember that there was a reference to this entity. */
12500 mark_used (expr);
12501 }
12502
12503 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
12504 {
12505 if (complain & tf_error)
12506 qualified_name_lookup_error (scope,
12507 TREE_OPERAND (qualified_id, 1),
12508 expr, input_location);
12509 return error_mark_node;
12510 }
12511
12512 if (is_template)
12513 expr = lookup_template_function (expr, template_args);
12514
12515 if (expr == error_mark_node && complain & tf_error)
12516 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12517 expr, input_location);
12518 else if (TYPE_P (scope))
12519 {
12520 expr = (adjust_result_of_qualified_name_lookup
12521 (expr, scope, current_nonlambda_class_type ()));
12522 expr = (finish_qualified_id_expr
12523 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12524 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12525 /*template_arg_p=*/false, complain));
12526 }
12527
12528 /* Expressions do not generally have reference type. */
12529 if (TREE_CODE (expr) != SCOPE_REF
12530 /* However, if we're about to form a pointer-to-member, we just
12531 want the referenced member referenced. */
12532 && TREE_CODE (expr) != OFFSET_REF)
12533 expr = convert_from_reference (expr);
12534
12535 return expr;
12536 }
12537
12538 /* Like tsubst, but deals with expressions. This function just replaces
12539 template parms; to finish processing the resultant expression, use
12540 tsubst_copy_and_build or tsubst_expr. */
12541
12542 static tree
tsubst_copy(tree t,tree args,tsubst_flags_t complain,tree in_decl)12543 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12544 {
12545 enum tree_code code;
12546 tree r;
12547
12548 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12549 return t;
12550
12551 code = TREE_CODE (t);
12552
12553 switch (code)
12554 {
12555 case PARM_DECL:
12556 r = retrieve_local_specialization (t);
12557
12558 if (r == NULL_TREE)
12559 {
12560 /* We get here for a use of 'this' in an NSDMI. */
12561 if (DECL_NAME (t) == this_identifier
12562 && at_function_scope_p ()
12563 && DECL_CONSTRUCTOR_P (current_function_decl))
12564 return current_class_ptr;
12565
12566 /* This can happen for a parameter name used later in a function
12567 declaration (such as in a late-specified return type). Just
12568 make a dummy decl, since it's only used for its type. */
12569 gcc_assert (cp_unevaluated_operand != 0);
12570 r = tsubst_decl (t, args, complain);
12571 /* Give it the template pattern as its context; its true context
12572 hasn't been instantiated yet and this is good enough for
12573 mangling. */
12574 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12575 }
12576
12577 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12578 r = ARGUMENT_PACK_SELECT_ARG (r);
12579 mark_used (r);
12580 return r;
12581
12582 case CONST_DECL:
12583 {
12584 tree enum_type;
12585 tree v;
12586
12587 if (DECL_TEMPLATE_PARM_P (t))
12588 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12589 /* There is no need to substitute into namespace-scope
12590 enumerators. */
12591 if (DECL_NAMESPACE_SCOPE_P (t))
12592 return t;
12593 /* If ARGS is NULL, then T is known to be non-dependent. */
12594 if (args == NULL_TREE)
12595 return integral_constant_value (t);
12596
12597 /* Unfortunately, we cannot just call lookup_name here.
12598 Consider:
12599
12600 template <int I> int f() {
12601 enum E { a = I };
12602 struct S { void g() { E e = a; } };
12603 };
12604
12605 When we instantiate f<7>::S::g(), say, lookup_name is not
12606 clever enough to find f<7>::a. */
12607 enum_type
12608 = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12609 /*entering_scope=*/0);
12610
12611 for (v = TYPE_VALUES (enum_type);
12612 v != NULL_TREE;
12613 v = TREE_CHAIN (v))
12614 if (TREE_PURPOSE (v) == DECL_NAME (t))
12615 return TREE_VALUE (v);
12616
12617 /* We didn't find the name. That should never happen; if
12618 name-lookup found it during preliminary parsing, we
12619 should find it again here during instantiation. */
12620 gcc_unreachable ();
12621 }
12622 return t;
12623
12624 case FIELD_DECL:
12625 if (PACK_EXPANSION_P (TREE_TYPE (t)))
12626 {
12627 /* Check for a local specialization set up by
12628 tsubst_pack_expansion. */
12629 if (tree r = retrieve_local_specialization (t))
12630 {
12631 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12632 r = ARGUMENT_PACK_SELECT_ARG (r);
12633 return r;
12634 }
12635
12636 /* When retrieving a capture pack from a generic lambda, remove the
12637 lambda call op's own template argument list from ARGS. Only the
12638 template arguments active for the closure type should be used to
12639 retrieve the pack specialization. */
12640 if (LAMBDA_FUNCTION_P (current_function_decl)
12641 && (template_class_depth (DECL_CONTEXT (t))
12642 != TMPL_ARGS_DEPTH (args)))
12643 args = strip_innermost_template_args (args, 1);
12644
12645 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
12646 tsubst_decl put in the hash table. */
12647 return retrieve_specialization (t, args, 0);
12648 }
12649
12650 if (DECL_CONTEXT (t))
12651 {
12652 tree ctx;
12653
12654 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12655 /*entering_scope=*/1);
12656 if (ctx != DECL_CONTEXT (t))
12657 {
12658 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12659 if (!r)
12660 {
12661 if (complain & tf_error)
12662 error ("using invalid field %qD", t);
12663 return error_mark_node;
12664 }
12665 return r;
12666 }
12667 }
12668
12669 return t;
12670
12671 case VAR_DECL:
12672 case FUNCTION_DECL:
12673 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12674 r = tsubst (t, args, complain, in_decl);
12675 else if (local_variable_p (t))
12676 {
12677 r = retrieve_local_specialization (t);
12678 if (r == NULL_TREE)
12679 {
12680 if (DECL_ANON_UNION_VAR_P (t))
12681 {
12682 /* Just use name lookup to find a member alias for an
12683 anonymous union, but then add it to the hash table. */
12684 r = lookup_name (DECL_NAME (t));
12685 gcc_assert (DECL_ANON_UNION_VAR_P (r));
12686 register_local_specialization (r, t);
12687 }
12688 else
12689 {
12690 /* This can happen for a variable used in a
12691 late-specified return type of a local lambda, or for a
12692 local static or constant. Building a new VAR_DECL
12693 should be OK in all those cases. */
12694 r = tsubst_decl (t, args, complain);
12695 if (decl_constant_var_p (r))
12696 /* A use of a local constant must decay to its value. */
12697 return integral_constant_value (r);
12698 gcc_assert (cp_unevaluated_operand || TREE_STATIC (r)
12699 || errorcount || sorrycount);
12700 return r;
12701 }
12702 }
12703 }
12704 else
12705 r = t;
12706 mark_used (r);
12707 return r;
12708
12709 case NAMESPACE_DECL:
12710 return t;
12711
12712 case OVERLOAD:
12713 /* An OVERLOAD will always be a non-dependent overload set; an
12714 overload set from function scope will just be represented with an
12715 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12716 gcc_assert (!uses_template_parms (t));
12717 return t;
12718
12719 case BASELINK:
12720 return tsubst_baselink (t, current_nonlambda_class_type (),
12721 args, complain, in_decl);
12722
12723 case TEMPLATE_DECL:
12724 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12725 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12726 args, complain, in_decl);
12727 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12728 return tsubst (t, args, complain, in_decl);
12729 else if (DECL_CLASS_SCOPE_P (t)
12730 && uses_template_parms (DECL_CONTEXT (t)))
12731 {
12732 /* Template template argument like the following example need
12733 special treatment:
12734
12735 template <template <class> class TT> struct C {};
12736 template <class T> struct D {
12737 template <class U> struct E {};
12738 C<E> c; // #1
12739 };
12740 D<int> d; // #2
12741
12742 We are processing the template argument `E' in #1 for
12743 the template instantiation #2. Originally, `E' is a
12744 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12745 have to substitute this with one having context `D<int>'. */
12746
12747 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12748 return lookup_field (context, DECL_NAME(t), 0, false);
12749 }
12750 else
12751 /* Ordinary template template argument. */
12752 return t;
12753
12754 case CAST_EXPR:
12755 case REINTERPRET_CAST_EXPR:
12756 case CONST_CAST_EXPR:
12757 case STATIC_CAST_EXPR:
12758 case DYNAMIC_CAST_EXPR:
12759 case IMPLICIT_CONV_EXPR:
12760 case CONVERT_EXPR:
12761 case NOP_EXPR:
12762 return build1
12763 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12764 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12765
12766 case SIZEOF_EXPR:
12767 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12768 {
12769
12770 tree expanded, op = TREE_OPERAND (t, 0);
12771 int len = 0;
12772
12773 if (SIZEOF_EXPR_TYPE_P (t))
12774 op = TREE_TYPE (op);
12775
12776 ++cp_unevaluated_operand;
12777 ++c_inhibit_evaluation_warnings;
12778 /* We only want to compute the number of arguments. */
12779 expanded = tsubst_pack_expansion (op, args, complain, in_decl);
12780 --cp_unevaluated_operand;
12781 --c_inhibit_evaluation_warnings;
12782
12783 if (TREE_CODE (expanded) == TREE_VEC)
12784 len = TREE_VEC_LENGTH (expanded);
12785
12786 if (expanded == error_mark_node)
12787 return error_mark_node;
12788 else if (PACK_EXPANSION_P (expanded)
12789 || (TREE_CODE (expanded) == TREE_VEC
12790 && len > 0
12791 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12792 {
12793 if (TREE_CODE (expanded) == TREE_VEC)
12794 expanded = TREE_VEC_ELT (expanded, len - 1);
12795
12796 if (TYPE_P (expanded))
12797 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12798 complain & tf_error);
12799 else
12800 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12801 complain & tf_error);
12802 }
12803 else
12804 return build_int_cst (size_type_node, len);
12805 }
12806 if (SIZEOF_EXPR_TYPE_P (t))
12807 {
12808 r = tsubst (TREE_TYPE (TREE_OPERAND (t, 0)),
12809 args, complain, in_decl);
12810 r = build1 (NOP_EXPR, r, error_mark_node);
12811 r = build1 (SIZEOF_EXPR,
12812 tsubst (TREE_TYPE (t), args, complain, in_decl), r);
12813 SIZEOF_EXPR_TYPE_P (r) = 1;
12814 return r;
12815 }
12816 /* Fall through */
12817
12818 case INDIRECT_REF:
12819 case NEGATE_EXPR:
12820 case TRUTH_NOT_EXPR:
12821 case BIT_NOT_EXPR:
12822 case ADDR_EXPR:
12823 case UNARY_PLUS_EXPR: /* Unary + */
12824 case ALIGNOF_EXPR:
12825 case AT_ENCODE_EXPR:
12826 case ARROW_EXPR:
12827 case THROW_EXPR:
12828 case TYPEID_EXPR:
12829 case REALPART_EXPR:
12830 case IMAGPART_EXPR:
12831 case PAREN_EXPR:
12832 return build1
12833 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12834 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12835
12836 case COMPONENT_REF:
12837 {
12838 tree object;
12839 tree name;
12840
12841 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12842 name = TREE_OPERAND (t, 1);
12843 if (TREE_CODE (name) == BIT_NOT_EXPR)
12844 {
12845 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12846 complain, in_decl);
12847 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12848 }
12849 else if (TREE_CODE (name) == SCOPE_REF
12850 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12851 {
12852 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12853 complain, in_decl);
12854 name = TREE_OPERAND (name, 1);
12855 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12856 complain, in_decl);
12857 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12858 name = build_qualified_name (/*type=*/NULL_TREE,
12859 base, name,
12860 /*template_p=*/false);
12861 }
12862 else if (BASELINK_P (name))
12863 name = tsubst_baselink (name,
12864 non_reference (TREE_TYPE (object)),
12865 args, complain,
12866 in_decl);
12867 else
12868 name = tsubst_copy (name, args, complain, in_decl);
12869 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12870 }
12871
12872 case PLUS_EXPR:
12873 case MINUS_EXPR:
12874 case MULT_EXPR:
12875 case TRUNC_DIV_EXPR:
12876 case CEIL_DIV_EXPR:
12877 case FLOOR_DIV_EXPR:
12878 case ROUND_DIV_EXPR:
12879 case EXACT_DIV_EXPR:
12880 case BIT_AND_EXPR:
12881 case BIT_IOR_EXPR:
12882 case BIT_XOR_EXPR:
12883 case TRUNC_MOD_EXPR:
12884 case FLOOR_MOD_EXPR:
12885 case TRUTH_ANDIF_EXPR:
12886 case TRUTH_ORIF_EXPR:
12887 case TRUTH_AND_EXPR:
12888 case TRUTH_OR_EXPR:
12889 case RSHIFT_EXPR:
12890 case LSHIFT_EXPR:
12891 case RROTATE_EXPR:
12892 case LROTATE_EXPR:
12893 case EQ_EXPR:
12894 case NE_EXPR:
12895 case MAX_EXPR:
12896 case MIN_EXPR:
12897 case LE_EXPR:
12898 case GE_EXPR:
12899 case LT_EXPR:
12900 case GT_EXPR:
12901 case COMPOUND_EXPR:
12902 case DOTSTAR_EXPR:
12903 case MEMBER_REF:
12904 case PREDECREMENT_EXPR:
12905 case PREINCREMENT_EXPR:
12906 case POSTDECREMENT_EXPR:
12907 case POSTINCREMENT_EXPR:
12908 return build_nt
12909 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12910 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12911
12912 case SCOPE_REF:
12913 return build_qualified_name (/*type=*/NULL_TREE,
12914 tsubst_copy (TREE_OPERAND (t, 0),
12915 args, complain, in_decl),
12916 tsubst_copy (TREE_OPERAND (t, 1),
12917 args, complain, in_decl),
12918 QUALIFIED_NAME_IS_TEMPLATE (t));
12919
12920 case ARRAY_REF:
12921 return build_nt
12922 (ARRAY_REF,
12923 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12924 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12925 NULL_TREE, NULL_TREE);
12926
12927 case CALL_EXPR:
12928 {
12929 int n = VL_EXP_OPERAND_LENGTH (t);
12930 tree result = build_vl_exp (CALL_EXPR, n);
12931 int i;
12932 for (i = 0; i < n; i++)
12933 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12934 complain, in_decl);
12935 return result;
12936 }
12937
12938 case COND_EXPR:
12939 case MODOP_EXPR:
12940 case PSEUDO_DTOR_EXPR:
12941 case VEC_PERM_EXPR:
12942 {
12943 r = build_nt
12944 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12945 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12946 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12947 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12948 return r;
12949 }
12950
12951 case NEW_EXPR:
12952 {
12953 r = build_nt
12954 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12955 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12956 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12957 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12958 return r;
12959 }
12960
12961 case DELETE_EXPR:
12962 {
12963 r = build_nt
12964 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12965 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12966 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12967 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12968 return r;
12969 }
12970
12971 case TEMPLATE_ID_EXPR:
12972 {
12973 /* Substituted template arguments */
12974 tree fn = TREE_OPERAND (t, 0);
12975 tree targs = TREE_OPERAND (t, 1);
12976
12977 fn = tsubst_copy (fn, args, complain, in_decl);
12978 if (targs)
12979 targs = tsubst_template_args (targs, args, complain, in_decl);
12980
12981 return lookup_template_function (fn, targs);
12982 }
12983
12984 case TREE_LIST:
12985 {
12986 tree purpose, value, chain;
12987
12988 if (t == void_list_node)
12989 return t;
12990
12991 purpose = TREE_PURPOSE (t);
12992 if (purpose)
12993 purpose = tsubst_copy (purpose, args, complain, in_decl);
12994 value = TREE_VALUE (t);
12995 if (value)
12996 value = tsubst_copy (value, args, complain, in_decl);
12997 chain = TREE_CHAIN (t);
12998 if (chain && chain != void_type_node)
12999 chain = tsubst_copy (chain, args, complain, in_decl);
13000 if (purpose == TREE_PURPOSE (t)
13001 && value == TREE_VALUE (t)
13002 && chain == TREE_CHAIN (t))
13003 return t;
13004 return tree_cons (purpose, value, chain);
13005 }
13006
13007 case RECORD_TYPE:
13008 case UNION_TYPE:
13009 case ENUMERAL_TYPE:
13010 case INTEGER_TYPE:
13011 case TEMPLATE_TYPE_PARM:
13012 case TEMPLATE_TEMPLATE_PARM:
13013 case BOUND_TEMPLATE_TEMPLATE_PARM:
13014 case TEMPLATE_PARM_INDEX:
13015 case POINTER_TYPE:
13016 case REFERENCE_TYPE:
13017 case OFFSET_TYPE:
13018 case FUNCTION_TYPE:
13019 case METHOD_TYPE:
13020 case ARRAY_TYPE:
13021 case TYPENAME_TYPE:
13022 case UNBOUND_CLASS_TEMPLATE:
13023 case TYPEOF_TYPE:
13024 case DECLTYPE_TYPE:
13025 case TYPE_DECL:
13026 return tsubst (t, args, complain, in_decl);
13027
13028 case USING_DECL:
13029 t = DECL_NAME (t);
13030 /* Fall through. */
13031 case IDENTIFIER_NODE:
13032 if (IDENTIFIER_TYPENAME_P (t))
13033 {
13034 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13035 return mangle_conv_op_name_for_type (new_type);
13036 }
13037 else
13038 return t;
13039
13040 case CONSTRUCTOR:
13041 /* This is handled by tsubst_copy_and_build. */
13042 gcc_unreachable ();
13043
13044 case VA_ARG_EXPR:
13045 return build_x_va_arg (EXPR_LOCATION (t),
13046 tsubst_copy (TREE_OPERAND (t, 0), args, complain,
13047 in_decl),
13048 tsubst (TREE_TYPE (t), args, complain, in_decl));
13049
13050 case CLEANUP_POINT_EXPR:
13051 /* We shouldn't have built any of these during initial template
13052 generation. Instead, they should be built during instantiation
13053 in response to the saved STMT_IS_FULL_EXPR_P setting. */
13054 gcc_unreachable ();
13055
13056 case OFFSET_REF:
13057 r = build2
13058 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
13059 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
13060 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
13061 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
13062 mark_used (TREE_OPERAND (r, 1));
13063 return r;
13064
13065 case EXPR_PACK_EXPANSION:
13066 error ("invalid use of pack expansion expression");
13067 return error_mark_node;
13068
13069 case NONTYPE_ARGUMENT_PACK:
13070 error ("use %<...%> to expand argument pack");
13071 return error_mark_node;
13072
13073 case INTEGER_CST:
13074 case REAL_CST:
13075 case STRING_CST:
13076 case COMPLEX_CST:
13077 {
13078 /* Instantiate any typedefs in the type. */
13079 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13080 r = fold_convert (type, t);
13081 gcc_assert (TREE_CODE (r) == code);
13082 return r;
13083 }
13084
13085 case PTRMEM_CST:
13086 /* These can sometimes show up in a partial instantiation, but never
13087 involve template parms. */
13088 gcc_assert (!uses_template_parms (t));
13089 return t;
13090
13091 default:
13092 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
13093 gcc_checking_assert (false);
13094 return t;
13095 }
13096 }
13097
13098 /* Like tsubst_copy, but specifically for OpenMP clauses. */
13099
13100 static tree
tsubst_omp_clauses(tree clauses,bool declare_simd,tree args,tsubst_flags_t complain,tree in_decl)13101 tsubst_omp_clauses (tree clauses, bool declare_simd,
13102 tree args, tsubst_flags_t complain, tree in_decl)
13103 {
13104 tree new_clauses = NULL, nc, oc;
13105
13106 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
13107 {
13108 nc = copy_node (oc);
13109 OMP_CLAUSE_CHAIN (nc) = new_clauses;
13110 new_clauses = nc;
13111
13112 switch (OMP_CLAUSE_CODE (nc))
13113 {
13114 case OMP_CLAUSE_LASTPRIVATE:
13115 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
13116 {
13117 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
13118 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
13119 in_decl, /*integral_constant_expression_p=*/false);
13120 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
13121 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
13122 }
13123 /* FALLTHRU */
13124 case OMP_CLAUSE_PRIVATE:
13125 case OMP_CLAUSE_SHARED:
13126 case OMP_CLAUSE_FIRSTPRIVATE:
13127 case OMP_CLAUSE_COPYIN:
13128 case OMP_CLAUSE_COPYPRIVATE:
13129 case OMP_CLAUSE_IF:
13130 case OMP_CLAUSE_NUM_THREADS:
13131 case OMP_CLAUSE_SCHEDULE:
13132 case OMP_CLAUSE_COLLAPSE:
13133 case OMP_CLAUSE_FINAL:
13134 case OMP_CLAUSE_DEPEND:
13135 case OMP_CLAUSE_FROM:
13136 case OMP_CLAUSE_TO:
13137 case OMP_CLAUSE_UNIFORM:
13138 case OMP_CLAUSE_MAP:
13139 case OMP_CLAUSE_DEVICE:
13140 case OMP_CLAUSE_DIST_SCHEDULE:
13141 case OMP_CLAUSE_NUM_TEAMS:
13142 case OMP_CLAUSE_THREAD_LIMIT:
13143 case OMP_CLAUSE_SAFELEN:
13144 case OMP_CLAUSE_SIMDLEN:
13145 OMP_CLAUSE_OPERAND (nc, 0)
13146 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
13147 in_decl, /*integral_constant_expression_p=*/false);
13148 break;
13149 case OMP_CLAUSE_REDUCTION:
13150 if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc))
13151 {
13152 tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc);
13153 if (TREE_CODE (placeholder) == SCOPE_REF)
13154 {
13155 tree scope = tsubst (TREE_OPERAND (placeholder, 0), args,
13156 complain, in_decl);
13157 OMP_CLAUSE_REDUCTION_PLACEHOLDER (nc)
13158 = build_qualified_name (NULL_TREE, scope,
13159 TREE_OPERAND (placeholder, 1),
13160 false);
13161 }
13162 else
13163 gcc_assert (identifier_p (placeholder));
13164 }
13165 OMP_CLAUSE_OPERAND (nc, 0)
13166 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
13167 in_decl, /*integral_constant_expression_p=*/false);
13168 break;
13169 case OMP_CLAUSE_LINEAR:
13170 case OMP_CLAUSE_ALIGNED:
13171 OMP_CLAUSE_OPERAND (nc, 0)
13172 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
13173 in_decl, /*integral_constant_expression_p=*/false);
13174 OMP_CLAUSE_OPERAND (nc, 1)
13175 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 1), args, complain,
13176 in_decl, /*integral_constant_expression_p=*/false);
13177 break;
13178
13179 case OMP_CLAUSE_NOWAIT:
13180 case OMP_CLAUSE_ORDERED:
13181 case OMP_CLAUSE_DEFAULT:
13182 case OMP_CLAUSE_UNTIED:
13183 case OMP_CLAUSE_MERGEABLE:
13184 case OMP_CLAUSE_INBRANCH:
13185 case OMP_CLAUSE_NOTINBRANCH:
13186 case OMP_CLAUSE_PROC_BIND:
13187 case OMP_CLAUSE_FOR:
13188 case OMP_CLAUSE_PARALLEL:
13189 case OMP_CLAUSE_SECTIONS:
13190 case OMP_CLAUSE_TASKGROUP:
13191 break;
13192 default:
13193 gcc_unreachable ();
13194 }
13195 }
13196
13197 new_clauses = nreverse (new_clauses);
13198 if (!declare_simd)
13199 new_clauses = finish_omp_clauses (new_clauses);
13200 return new_clauses;
13201 }
13202
13203 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
13204
13205 static tree
tsubst_copy_asm_operands(tree t,tree args,tsubst_flags_t complain,tree in_decl)13206 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
13207 tree in_decl)
13208 {
13209 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
13210
13211 tree purpose, value, chain;
13212
13213 if (t == NULL)
13214 return t;
13215
13216 if (TREE_CODE (t) != TREE_LIST)
13217 return tsubst_copy_and_build (t, args, complain, in_decl,
13218 /*function_p=*/false,
13219 /*integral_constant_expression_p=*/false);
13220
13221 if (t == void_list_node)
13222 return t;
13223
13224 purpose = TREE_PURPOSE (t);
13225 if (purpose)
13226 purpose = RECUR (purpose);
13227 value = TREE_VALUE (t);
13228 if (value)
13229 {
13230 if (TREE_CODE (value) != LABEL_DECL)
13231 value = RECUR (value);
13232 else
13233 {
13234 value = lookup_label (DECL_NAME (value));
13235 gcc_assert (TREE_CODE (value) == LABEL_DECL);
13236 TREE_USED (value) = 1;
13237 }
13238 }
13239 chain = TREE_CHAIN (t);
13240 if (chain && chain != void_type_node)
13241 chain = RECUR (chain);
13242 return tree_cons (purpose, value, chain);
13243 #undef RECUR
13244 }
13245
13246 /* Substitute one OMP_FOR iterator. */
13247
13248 static void
tsubst_omp_for_iterator(tree t,int i,tree declv,tree initv,tree condv,tree incrv,tree * clauses,tree args,tsubst_flags_t complain,tree in_decl,bool integral_constant_expression_p)13249 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
13250 tree condv, tree incrv, tree *clauses,
13251 tree args, tsubst_flags_t complain, tree in_decl,
13252 bool integral_constant_expression_p)
13253 {
13254 #define RECUR(NODE) \
13255 tsubst_expr ((NODE), args, complain, in_decl, \
13256 integral_constant_expression_p)
13257 tree decl, init, cond, incr;
13258
13259 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
13260 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
13261 decl = TREE_OPERAND (init, 0);
13262 init = TREE_OPERAND (init, 1);
13263 tree decl_expr = NULL_TREE;
13264 if (init && TREE_CODE (init) == DECL_EXPR)
13265 {
13266 /* We need to jump through some hoops to handle declarations in the
13267 for-init-statement, since we might need to handle auto deduction,
13268 but we need to keep control of initialization. */
13269 decl_expr = init;
13270 init = DECL_INITIAL (DECL_EXPR_DECL (init));
13271 decl = tsubst_decl (decl, args, complain);
13272 }
13273 else
13274 decl = RECUR (decl);
13275 init = RECUR (init);
13276
13277 tree auto_node = type_uses_auto (TREE_TYPE (decl));
13278 if (auto_node && init)
13279 TREE_TYPE (decl)
13280 = do_auto_deduction (TREE_TYPE (decl), init, auto_node);
13281
13282 gcc_assert (!type_dependent_expression_p (decl));
13283
13284 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
13285 {
13286 if (decl_expr)
13287 {
13288 /* Declare the variable, but don't let that initialize it. */
13289 tree init_sav = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13290 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL_TREE;
13291 RECUR (decl_expr);
13292 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init_sav;
13293 }
13294
13295 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
13296 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
13297 if (TREE_CODE (incr) == MODIFY_EXPR)
13298 incr = build_x_modify_expr (EXPR_LOCATION (incr),
13299 RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
13300 RECUR (TREE_OPERAND (incr, 1)),
13301 complain);
13302 else
13303 incr = RECUR (incr);
13304 TREE_VEC_ELT (declv, i) = decl;
13305 TREE_VEC_ELT (initv, i) = init;
13306 TREE_VEC_ELT (condv, i) = cond;
13307 TREE_VEC_ELT (incrv, i) = incr;
13308 return;
13309 }
13310
13311 if (decl_expr)
13312 {
13313 /* Declare and initialize the variable. */
13314 RECUR (decl_expr);
13315 init = NULL_TREE;
13316 }
13317 else if (init)
13318 {
13319 tree c;
13320 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
13321 {
13322 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
13323 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
13324 && OMP_CLAUSE_DECL (c) == decl)
13325 break;
13326 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
13327 && OMP_CLAUSE_DECL (c) == decl)
13328 error ("iteration variable %qD should not be firstprivate", decl);
13329 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
13330 && OMP_CLAUSE_DECL (c) == decl)
13331 error ("iteration variable %qD should not be reduction", decl);
13332 }
13333 if (c == NULL)
13334 {
13335 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
13336 OMP_CLAUSE_DECL (c) = decl;
13337 c = finish_omp_clauses (c);
13338 if (c)
13339 {
13340 OMP_CLAUSE_CHAIN (c) = *clauses;
13341 *clauses = c;
13342 }
13343 }
13344 }
13345 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
13346 if (COMPARISON_CLASS_P (cond))
13347 cond = build2 (TREE_CODE (cond), boolean_type_node,
13348 RECUR (TREE_OPERAND (cond, 0)),
13349 RECUR (TREE_OPERAND (cond, 1)));
13350 else
13351 cond = RECUR (cond);
13352 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
13353 switch (TREE_CODE (incr))
13354 {
13355 case PREINCREMENT_EXPR:
13356 case PREDECREMENT_EXPR:
13357 case POSTINCREMENT_EXPR:
13358 case POSTDECREMENT_EXPR:
13359 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
13360 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
13361 break;
13362 case MODIFY_EXPR:
13363 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
13364 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
13365 {
13366 tree rhs = TREE_OPERAND (incr, 1);
13367 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
13368 RECUR (TREE_OPERAND (incr, 0)),
13369 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
13370 RECUR (TREE_OPERAND (rhs, 0)),
13371 RECUR (TREE_OPERAND (rhs, 1))));
13372 }
13373 else
13374 incr = RECUR (incr);
13375 break;
13376 case MODOP_EXPR:
13377 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
13378 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
13379 {
13380 tree lhs = RECUR (TREE_OPERAND (incr, 0));
13381 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
13382 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
13383 TREE_TYPE (decl), lhs,
13384 RECUR (TREE_OPERAND (incr, 2))));
13385 }
13386 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
13387 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
13388 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
13389 {
13390 tree rhs = TREE_OPERAND (incr, 2);
13391 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
13392 RECUR (TREE_OPERAND (incr, 0)),
13393 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
13394 RECUR (TREE_OPERAND (rhs, 0)),
13395 RECUR (TREE_OPERAND (rhs, 1))));
13396 }
13397 else
13398 incr = RECUR (incr);
13399 break;
13400 default:
13401 incr = RECUR (incr);
13402 break;
13403 }
13404
13405 TREE_VEC_ELT (declv, i) = decl;
13406 TREE_VEC_ELT (initv, i) = init;
13407 TREE_VEC_ELT (condv, i) = cond;
13408 TREE_VEC_ELT (incrv, i) = incr;
13409 #undef RECUR
13410 }
13411
13412 /* Like tsubst_copy for expressions, etc. but also does semantic
13413 processing. */
13414
13415 static tree
tsubst_expr(tree t,tree args,tsubst_flags_t complain,tree in_decl,bool integral_constant_expression_p)13416 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
13417 bool integral_constant_expression_p)
13418 {
13419 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
13420 #define RECUR(NODE) \
13421 tsubst_expr ((NODE), args, complain, in_decl, \
13422 integral_constant_expression_p)
13423
13424 tree stmt, tmp;
13425 tree r;
13426 location_t loc;
13427
13428 if (t == NULL_TREE || t == error_mark_node)
13429 return t;
13430
13431 loc = input_location;
13432 if (EXPR_HAS_LOCATION (t))
13433 input_location = EXPR_LOCATION (t);
13434 if (STATEMENT_CODE_P (TREE_CODE (t)))
13435 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
13436
13437 switch (TREE_CODE (t))
13438 {
13439 case STATEMENT_LIST:
13440 {
13441 tree_stmt_iterator i;
13442 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
13443 RECUR (tsi_stmt (i));
13444 break;
13445 }
13446
13447 case CTOR_INITIALIZER:
13448 finish_mem_initializers (tsubst_initializer_list
13449 (TREE_OPERAND (t, 0), args));
13450 break;
13451
13452 case RETURN_EXPR:
13453 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
13454 break;
13455
13456 case EXPR_STMT:
13457 tmp = RECUR (EXPR_STMT_EXPR (t));
13458 if (EXPR_STMT_STMT_EXPR_RESULT (t))
13459 finish_stmt_expr_expr (tmp, cur_stmt_expr);
13460 else
13461 finish_expr_stmt (tmp);
13462 break;
13463
13464 case USING_STMT:
13465 do_using_directive (USING_STMT_NAMESPACE (t));
13466 break;
13467
13468 case DECL_EXPR:
13469 {
13470 tree decl, pattern_decl;
13471 tree init;
13472
13473 pattern_decl = decl = DECL_EXPR_DECL (t);
13474 if (TREE_CODE (decl) == LABEL_DECL)
13475 finish_label_decl (DECL_NAME (decl));
13476 else if (TREE_CODE (decl) == USING_DECL)
13477 {
13478 tree scope = USING_DECL_SCOPE (decl);
13479 tree name = DECL_NAME (decl);
13480 tree decl;
13481
13482 scope = tsubst (scope, args, complain, in_decl);
13483 decl = lookup_qualified_name (scope, name,
13484 /*is_type_p=*/false,
13485 /*complain=*/false);
13486 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
13487 qualified_name_lookup_error (scope, name, decl, input_location);
13488 else
13489 do_local_using_decl (decl, scope, name);
13490 }
13491 else if (DECL_PACK_P (decl))
13492 {
13493 /* Don't build up decls for a variadic capture proxy, we'll
13494 instantiate the elements directly as needed. */
13495 break;
13496 }
13497 else
13498 {
13499 init = DECL_INITIAL (decl);
13500 decl = tsubst (decl, args, complain, in_decl);
13501 if (decl != error_mark_node)
13502 {
13503 /* By marking the declaration as instantiated, we avoid
13504 trying to instantiate it. Since instantiate_decl can't
13505 handle local variables, and since we've already done
13506 all that needs to be done, that's the right thing to
13507 do. */
13508 if (VAR_P (decl))
13509 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13510 if (VAR_P (decl)
13511 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
13512 /* Anonymous aggregates are a special case. */
13513 finish_anon_union (decl);
13514 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
13515 {
13516 DECL_CONTEXT (decl) = current_function_decl;
13517 if (DECL_NAME (decl) == this_identifier)
13518 {
13519 tree lam = DECL_CONTEXT (current_function_decl);
13520 lam = CLASSTYPE_LAMBDA_EXPR (lam);
13521 LAMBDA_EXPR_THIS_CAPTURE (lam) = decl;
13522 }
13523 insert_capture_proxy (decl);
13524 }
13525 else if (DECL_IMPLICIT_TYPEDEF_P (t))
13526 /* We already did a pushtag. */;
13527 else if (TREE_CODE (decl) == FUNCTION_DECL
13528 && DECL_OMP_DECLARE_REDUCTION_P (decl)
13529 && DECL_FUNCTION_SCOPE_P (pattern_decl))
13530 {
13531 DECL_CONTEXT (decl) = NULL_TREE;
13532 pushdecl (decl);
13533 DECL_CONTEXT (decl) = current_function_decl;
13534 cp_check_omp_declare_reduction (decl);
13535 }
13536 else
13537 {
13538 int const_init = false;
13539 maybe_push_decl (decl);
13540 if (VAR_P (decl)
13541 && DECL_PRETTY_FUNCTION_P (decl))
13542 {
13543 /* For __PRETTY_FUNCTION__ we have to adjust the
13544 initializer. */
13545 const char *const name
13546 = cxx_printable_name (current_function_decl, 2);
13547 init = cp_fname_init (name, &TREE_TYPE (decl));
13548 }
13549 else
13550 {
13551 tree t = RECUR (init);
13552
13553 if (init && !t)
13554 {
13555 /* If we had an initializer but it
13556 instantiated to nothing,
13557 value-initialize the object. This will
13558 only occur when the initializer was a
13559 pack expansion where the parameter packs
13560 used in that expansion were of length
13561 zero. */
13562 init = build_value_init (TREE_TYPE (decl),
13563 complain);
13564 if (TREE_CODE (init) == AGGR_INIT_EXPR)
13565 init = get_target_expr_sfinae (init, complain);
13566 }
13567 else
13568 init = t;
13569 }
13570
13571 if (VAR_P (decl))
13572 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
13573 (pattern_decl));
13574 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
13575 }
13576 }
13577 }
13578
13579 break;
13580 }
13581
13582 case FOR_STMT:
13583 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
13584 RECUR (FOR_INIT_STMT (t));
13585 finish_for_init_stmt (stmt);
13586 tmp = RECUR (FOR_COND (t));
13587 finish_for_cond (tmp, stmt, false);
13588 tmp = RECUR (FOR_EXPR (t));
13589 finish_for_expr (tmp, stmt);
13590 RECUR (FOR_BODY (t));
13591 finish_for_stmt (stmt);
13592 break;
13593
13594 case RANGE_FOR_STMT:
13595 {
13596 tree decl, expr;
13597 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
13598 decl = RANGE_FOR_DECL (t);
13599 decl = tsubst (decl, args, complain, in_decl);
13600 maybe_push_decl (decl);
13601 expr = RECUR (RANGE_FOR_EXPR (t));
13602 stmt = cp_convert_range_for (stmt, decl, expr, RANGE_FOR_IVDEP (t));
13603 RECUR (RANGE_FOR_BODY (t));
13604 finish_for_stmt (stmt);
13605 }
13606 break;
13607
13608 case WHILE_STMT:
13609 stmt = begin_while_stmt ();
13610 tmp = RECUR (WHILE_COND (t));
13611 finish_while_stmt_cond (tmp, stmt, false);
13612 RECUR (WHILE_BODY (t));
13613 finish_while_stmt (stmt);
13614 break;
13615
13616 case DO_STMT:
13617 stmt = begin_do_stmt ();
13618 RECUR (DO_BODY (t));
13619 finish_do_body (stmt);
13620 tmp = RECUR (DO_COND (t));
13621 finish_do_stmt (tmp, stmt, false);
13622 break;
13623
13624 case IF_STMT:
13625 stmt = begin_if_stmt ();
13626 tmp = RECUR (IF_COND (t));
13627 finish_if_stmt_cond (tmp, stmt);
13628 RECUR (THEN_CLAUSE (t));
13629 finish_then_clause (stmt);
13630
13631 if (ELSE_CLAUSE (t))
13632 {
13633 begin_else_clause (stmt);
13634 RECUR (ELSE_CLAUSE (t));
13635 finish_else_clause (stmt);
13636 }
13637
13638 finish_if_stmt (stmt);
13639 break;
13640
13641 case BIND_EXPR:
13642 if (BIND_EXPR_BODY_BLOCK (t))
13643 stmt = begin_function_body ();
13644 else
13645 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
13646 ? BCS_TRY_BLOCK : 0);
13647
13648 RECUR (BIND_EXPR_BODY (t));
13649
13650 if (BIND_EXPR_BODY_BLOCK (t))
13651 finish_function_body (stmt);
13652 else
13653 finish_compound_stmt (stmt);
13654 break;
13655
13656 case BREAK_STMT:
13657 finish_break_stmt ();
13658 break;
13659
13660 case CONTINUE_STMT:
13661 finish_continue_stmt ();
13662 break;
13663
13664 case SWITCH_STMT:
13665 stmt = begin_switch_stmt ();
13666 tmp = RECUR (SWITCH_STMT_COND (t));
13667 finish_switch_cond (tmp, stmt);
13668 RECUR (SWITCH_STMT_BODY (t));
13669 finish_switch_stmt (stmt);
13670 break;
13671
13672 case CASE_LABEL_EXPR:
13673 finish_case_label (EXPR_LOCATION (t),
13674 RECUR (CASE_LOW (t)),
13675 RECUR (CASE_HIGH (t)));
13676 break;
13677
13678 case LABEL_EXPR:
13679 {
13680 tree decl = LABEL_EXPR_LABEL (t);
13681 tree label;
13682
13683 label = finish_label_stmt (DECL_NAME (decl));
13684 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13685 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13686 }
13687 break;
13688
13689 case GOTO_EXPR:
13690 tmp = GOTO_DESTINATION (t);
13691 if (TREE_CODE (tmp) != LABEL_DECL)
13692 /* Computed goto's must be tsubst'd into. On the other hand,
13693 non-computed gotos must not be; the identifier in question
13694 will have no binding. */
13695 tmp = RECUR (tmp);
13696 else
13697 tmp = DECL_NAME (tmp);
13698 finish_goto_stmt (tmp);
13699 break;
13700
13701 case ASM_EXPR:
13702 tmp = finish_asm_stmt
13703 (ASM_VOLATILE_P (t),
13704 RECUR (ASM_STRING (t)),
13705 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13706 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13707 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13708 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13709 {
13710 tree asm_expr = tmp;
13711 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13712 asm_expr = TREE_OPERAND (asm_expr, 0);
13713 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13714 }
13715 break;
13716
13717 case TRY_BLOCK:
13718 if (CLEANUP_P (t))
13719 {
13720 stmt = begin_try_block ();
13721 RECUR (TRY_STMTS (t));
13722 finish_cleanup_try_block (stmt);
13723 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13724 }
13725 else
13726 {
13727 tree compound_stmt = NULL_TREE;
13728
13729 if (FN_TRY_BLOCK_P (t))
13730 stmt = begin_function_try_block (&compound_stmt);
13731 else
13732 stmt = begin_try_block ();
13733
13734 RECUR (TRY_STMTS (t));
13735
13736 if (FN_TRY_BLOCK_P (t))
13737 finish_function_try_block (stmt);
13738 else
13739 finish_try_block (stmt);
13740
13741 RECUR (TRY_HANDLERS (t));
13742 if (FN_TRY_BLOCK_P (t))
13743 finish_function_handler_sequence (stmt, compound_stmt);
13744 else
13745 finish_handler_sequence (stmt);
13746 }
13747 break;
13748
13749 case HANDLER:
13750 {
13751 tree decl = HANDLER_PARMS (t);
13752
13753 if (decl)
13754 {
13755 decl = tsubst (decl, args, complain, in_decl);
13756 /* Prevent instantiate_decl from trying to instantiate
13757 this variable. We've already done all that needs to be
13758 done. */
13759 if (decl != error_mark_node)
13760 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13761 }
13762 stmt = begin_handler ();
13763 finish_handler_parms (decl, stmt);
13764 RECUR (HANDLER_BODY (t));
13765 finish_handler (stmt);
13766 }
13767 break;
13768
13769 case TAG_DEFN:
13770 tmp = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13771 if (CLASS_TYPE_P (tmp))
13772 {
13773 /* Local classes are not independent templates; they are
13774 instantiated along with their containing function. And this
13775 way we don't have to deal with pushing out of one local class
13776 to instantiate a member of another local class. */
13777 tree fn;
13778 /* Closures are handled by the LAMBDA_EXPR. */
13779 gcc_assert (!LAMBDA_TYPE_P (TREE_TYPE (t)));
13780 complete_type (tmp);
13781 for (fn = TYPE_METHODS (tmp); fn; fn = DECL_CHAIN (fn))
13782 if (!DECL_ARTIFICIAL (fn))
13783 instantiate_decl (fn, /*defer_ok*/0, /*expl_inst_class*/false);
13784 }
13785 break;
13786
13787 case STATIC_ASSERT:
13788 {
13789 tree condition;
13790
13791 ++c_inhibit_evaluation_warnings;
13792 condition =
13793 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13794 args,
13795 complain, in_decl,
13796 /*integral_constant_expression_p=*/true);
13797 --c_inhibit_evaluation_warnings;
13798
13799 finish_static_assert (condition,
13800 STATIC_ASSERT_MESSAGE (t),
13801 STATIC_ASSERT_SOURCE_LOCATION (t),
13802 /*member_p=*/false);
13803 }
13804 break;
13805
13806 case OMP_PARALLEL:
13807 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t), false,
13808 args, complain, in_decl);
13809 stmt = begin_omp_parallel ();
13810 RECUR (OMP_PARALLEL_BODY (t));
13811 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13812 = OMP_PARALLEL_COMBINED (t);
13813 break;
13814
13815 case OMP_TASK:
13816 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t), false,
13817 args, complain, in_decl);
13818 stmt = begin_omp_task ();
13819 RECUR (OMP_TASK_BODY (t));
13820 finish_omp_task (tmp, stmt);
13821 break;
13822
13823 case OMP_FOR:
13824 case OMP_SIMD:
13825 case CILK_SIMD:
13826 case OMP_DISTRIBUTE:
13827 {
13828 tree clauses, body, pre_body;
13829 tree declv = NULL_TREE, initv = NULL_TREE, condv = NULL_TREE;
13830 tree incrv = NULL_TREE;
13831 int i;
13832
13833 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t), false,
13834 args, complain, in_decl);
13835 if (OMP_FOR_INIT (t) != NULL_TREE)
13836 {
13837 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13838 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13839 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13840 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13841 }
13842
13843 stmt = begin_omp_structured_block ();
13844
13845 pre_body = push_stmt_list ();
13846 RECUR (OMP_FOR_PRE_BODY (t));
13847 pre_body = pop_stmt_list (pre_body);
13848
13849 if (OMP_FOR_INIT (t) != NULL_TREE)
13850 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13851 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13852 &clauses, args, complain, in_decl,
13853 integral_constant_expression_p);
13854
13855 body = push_stmt_list ();
13856 RECUR (OMP_FOR_BODY (t));
13857 body = pop_stmt_list (body);
13858
13859 if (OMP_FOR_INIT (t) != NULL_TREE)
13860 t = finish_omp_for (EXPR_LOCATION (t), TREE_CODE (t), declv, initv,
13861 condv, incrv, body, pre_body, clauses);
13862 else
13863 {
13864 t = make_node (TREE_CODE (t));
13865 TREE_TYPE (t) = void_type_node;
13866 OMP_FOR_BODY (t) = body;
13867 OMP_FOR_PRE_BODY (t) = pre_body;
13868 OMP_FOR_CLAUSES (t) = clauses;
13869 SET_EXPR_LOCATION (t, EXPR_LOCATION (t));
13870 add_stmt (t);
13871 }
13872
13873 add_stmt (finish_omp_structured_block (stmt));
13874 }
13875 break;
13876
13877 case OMP_SECTIONS:
13878 case OMP_SINGLE:
13879 case OMP_TEAMS:
13880 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false,
13881 args, complain, in_decl);
13882 stmt = push_stmt_list ();
13883 RECUR (OMP_BODY (t));
13884 stmt = pop_stmt_list (stmt);
13885
13886 t = copy_node (t);
13887 OMP_BODY (t) = stmt;
13888 OMP_CLAUSES (t) = tmp;
13889 add_stmt (t);
13890 break;
13891
13892 case OMP_TARGET_DATA:
13893 case OMP_TARGET:
13894 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false,
13895 args, complain, in_decl);
13896 keep_next_level (true);
13897 stmt = begin_omp_structured_block ();
13898
13899 RECUR (OMP_BODY (t));
13900 stmt = finish_omp_structured_block (stmt);
13901
13902 t = copy_node (t);
13903 OMP_BODY (t) = stmt;
13904 OMP_CLAUSES (t) = tmp;
13905 add_stmt (t);
13906 break;
13907
13908 case OMP_TARGET_UPDATE:
13909 tmp = tsubst_omp_clauses (OMP_TARGET_UPDATE_CLAUSES (t), false,
13910 args, complain, in_decl);
13911 t = copy_node (t);
13912 OMP_CLAUSES (t) = tmp;
13913 add_stmt (t);
13914 break;
13915
13916 case OMP_SECTION:
13917 case OMP_CRITICAL:
13918 case OMP_MASTER:
13919 case OMP_TASKGROUP:
13920 case OMP_ORDERED:
13921 stmt = push_stmt_list ();
13922 RECUR (OMP_BODY (t));
13923 stmt = pop_stmt_list (stmt);
13924
13925 t = copy_node (t);
13926 OMP_BODY (t) = stmt;
13927 add_stmt (t);
13928 break;
13929
13930 case OMP_ATOMIC:
13931 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13932 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13933 {
13934 tree op1 = TREE_OPERAND (t, 1);
13935 tree rhs1 = NULL_TREE;
13936 tree lhs, rhs;
13937 if (TREE_CODE (op1) == COMPOUND_EXPR)
13938 {
13939 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13940 op1 = TREE_OPERAND (op1, 1);
13941 }
13942 lhs = RECUR (TREE_OPERAND (op1, 0));
13943 rhs = RECUR (TREE_OPERAND (op1, 1));
13944 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13945 NULL_TREE, NULL_TREE, rhs1,
13946 OMP_ATOMIC_SEQ_CST (t));
13947 }
13948 else
13949 {
13950 tree op1 = TREE_OPERAND (t, 1);
13951 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13952 tree rhs1 = NULL_TREE;
13953 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13954 enum tree_code opcode = NOP_EXPR;
13955 if (code == OMP_ATOMIC_READ)
13956 {
13957 v = RECUR (TREE_OPERAND (op1, 0));
13958 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13959 }
13960 else if (code == OMP_ATOMIC_CAPTURE_OLD
13961 || code == OMP_ATOMIC_CAPTURE_NEW)
13962 {
13963 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13964 v = RECUR (TREE_OPERAND (op1, 0));
13965 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13966 if (TREE_CODE (op11) == COMPOUND_EXPR)
13967 {
13968 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13969 op11 = TREE_OPERAND (op11, 1);
13970 }
13971 lhs = RECUR (TREE_OPERAND (op11, 0));
13972 rhs = RECUR (TREE_OPERAND (op11, 1));
13973 opcode = TREE_CODE (op11);
13974 if (opcode == MODIFY_EXPR)
13975 opcode = NOP_EXPR;
13976 }
13977 else
13978 {
13979 code = OMP_ATOMIC;
13980 lhs = RECUR (TREE_OPERAND (op1, 0));
13981 rhs = RECUR (TREE_OPERAND (op1, 1));
13982 }
13983 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1,
13984 OMP_ATOMIC_SEQ_CST (t));
13985 }
13986 break;
13987
13988 case TRANSACTION_EXPR:
13989 {
13990 int flags = 0;
13991 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13992 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13993
13994 if (TRANSACTION_EXPR_IS_STMT (t))
13995 {
13996 tree body = TRANSACTION_EXPR_BODY (t);
13997 tree noex = NULL_TREE;
13998 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13999 {
14000 noex = MUST_NOT_THROW_COND (body);
14001 if (noex == NULL_TREE)
14002 noex = boolean_true_node;
14003 body = TREE_OPERAND (body, 0);
14004 }
14005 stmt = begin_transaction_stmt (input_location, NULL, flags);
14006 RECUR (body);
14007 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
14008 }
14009 else
14010 {
14011 stmt = build_transaction_expr (EXPR_LOCATION (t),
14012 RECUR (TRANSACTION_EXPR_BODY (t)),
14013 flags, NULL_TREE);
14014 RETURN (stmt);
14015 }
14016 }
14017 break;
14018
14019 case MUST_NOT_THROW_EXPR:
14020 RETURN (build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
14021 RECUR (MUST_NOT_THROW_COND (t))));
14022
14023 case EXPR_PACK_EXPANSION:
14024 error ("invalid use of pack expansion expression");
14025 RETURN (error_mark_node);
14026
14027 case NONTYPE_ARGUMENT_PACK:
14028 error ("use %<...%> to expand argument pack");
14029 RETURN (error_mark_node);
14030
14031 case CILK_SPAWN_STMT:
14032 cfun->calls_cilk_spawn = 1;
14033 RETURN (build_cilk_spawn (EXPR_LOCATION (t), RECUR (CILK_SPAWN_FN (t))));
14034
14035 case CILK_SYNC_STMT:
14036 RETURN (build_cilk_sync ());
14037
14038 case COMPOUND_EXPR:
14039 tmp = RECUR (TREE_OPERAND (t, 0));
14040 if (tmp == NULL_TREE)
14041 /* If the first operand was a statement, we're done with it. */
14042 RETURN (RECUR (TREE_OPERAND (t, 1)));
14043 RETURN (build_x_compound_expr (EXPR_LOCATION (t), tmp,
14044 RECUR (TREE_OPERAND (t, 1)),
14045 complain));
14046
14047 case ANNOTATE_EXPR:
14048 tmp = RECUR (TREE_OPERAND (t, 0));
14049 RETURN (build2_loc (EXPR_LOCATION (t), ANNOTATE_EXPR,
14050 TREE_TYPE (tmp), tmp, RECUR (TREE_OPERAND (t, 1))));
14051
14052 default:
14053 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
14054
14055 RETURN (tsubst_copy_and_build (t, args, complain, in_decl,
14056 /*function_p=*/false,
14057 integral_constant_expression_p));
14058 }
14059
14060 RETURN (NULL_TREE);
14061 out:
14062 input_location = loc;
14063 return r;
14064 #undef RECUR
14065 #undef RETURN
14066 }
14067
14068 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
14069 function. For description of the body see comment above
14070 cp_parser_omp_declare_reduction_exprs. */
14071
14072 static void
tsubst_omp_udr(tree t,tree args,tsubst_flags_t complain,tree in_decl)14073 tsubst_omp_udr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
14074 {
14075 if (t == NULL_TREE || t == error_mark_node)
14076 return;
14077
14078 gcc_assert (TREE_CODE (t) == STATEMENT_LIST);
14079
14080 tree_stmt_iterator tsi;
14081 int i;
14082 tree stmts[7];
14083 memset (stmts, 0, sizeof stmts);
14084 for (i = 0, tsi = tsi_start (t);
14085 i < 7 && !tsi_end_p (tsi);
14086 i++, tsi_next (&tsi))
14087 stmts[i] = tsi_stmt (tsi);
14088 gcc_assert (tsi_end_p (tsi));
14089
14090 if (i >= 3)
14091 {
14092 gcc_assert (TREE_CODE (stmts[0]) == DECL_EXPR
14093 && TREE_CODE (stmts[1]) == DECL_EXPR);
14094 tree omp_out = tsubst (DECL_EXPR_DECL (stmts[0]),
14095 args, complain, in_decl);
14096 tree omp_in = tsubst (DECL_EXPR_DECL (stmts[1]),
14097 args, complain, in_decl);
14098 DECL_CONTEXT (omp_out) = current_function_decl;
14099 DECL_CONTEXT (omp_in) = current_function_decl;
14100 keep_next_level (true);
14101 tree block = begin_omp_structured_block ();
14102 tsubst_expr (stmts[2], args, complain, in_decl, false);
14103 block = finish_omp_structured_block (block);
14104 block = maybe_cleanup_point_expr_void (block);
14105 add_decl_expr (omp_out);
14106 if (TREE_NO_WARNING (DECL_EXPR_DECL (stmts[0])))
14107 TREE_NO_WARNING (omp_out) = 1;
14108 add_decl_expr (omp_in);
14109 finish_expr_stmt (block);
14110 }
14111 if (i >= 6)
14112 {
14113 gcc_assert (TREE_CODE (stmts[3]) == DECL_EXPR
14114 && TREE_CODE (stmts[4]) == DECL_EXPR);
14115 tree omp_priv = tsubst (DECL_EXPR_DECL (stmts[3]),
14116 args, complain, in_decl);
14117 tree omp_orig = tsubst (DECL_EXPR_DECL (stmts[4]),
14118 args, complain, in_decl);
14119 DECL_CONTEXT (omp_priv) = current_function_decl;
14120 DECL_CONTEXT (omp_orig) = current_function_decl;
14121 keep_next_level (true);
14122 tree block = begin_omp_structured_block ();
14123 tsubst_expr (stmts[5], args, complain, in_decl, false);
14124 block = finish_omp_structured_block (block);
14125 block = maybe_cleanup_point_expr_void (block);
14126 cp_walk_tree (&block, cp_remove_omp_priv_cleanup_stmt, omp_priv, NULL);
14127 add_decl_expr (omp_priv);
14128 add_decl_expr (omp_orig);
14129 finish_expr_stmt (block);
14130 if (i == 7)
14131 add_decl_expr (omp_orig);
14132 }
14133 }
14134
14135 /* T is a postfix-expression that is not being used in a function
14136 call. Return the substituted version of T. */
14137
14138 static tree
tsubst_non_call_postfix_expression(tree t,tree args,tsubst_flags_t complain,tree in_decl)14139 tsubst_non_call_postfix_expression (tree t, tree args,
14140 tsubst_flags_t complain,
14141 tree in_decl)
14142 {
14143 if (TREE_CODE (t) == SCOPE_REF)
14144 t = tsubst_qualified_id (t, args, complain, in_decl,
14145 /*done=*/false, /*address_p=*/false);
14146 else
14147 t = tsubst_copy_and_build (t, args, complain, in_decl,
14148 /*function_p=*/false,
14149 /*integral_constant_expression_p=*/false);
14150
14151 return t;
14152 }
14153
14154 /* Sentinel to disable certain warnings during template substitution. */
14155
14156 struct warning_sentinel {
14157 int &flag;
14158 int val;
14159 warning_sentinel(int& flag, bool suppress=true)
flagwarning_sentinel14160 : flag(flag), val(flag) { if (suppress) flag = 0; }
~warning_sentinelwarning_sentinel14161 ~warning_sentinel() { flag = val; }
14162 };
14163
14164 /* Like tsubst but deals with expressions and performs semantic
14165 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
14166
14167 tree
tsubst_copy_and_build(tree t,tree args,tsubst_flags_t complain,tree in_decl,bool function_p,bool integral_constant_expression_p)14168 tsubst_copy_and_build (tree t,
14169 tree args,
14170 tsubst_flags_t complain,
14171 tree in_decl,
14172 bool function_p,
14173 bool integral_constant_expression_p)
14174 {
14175 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
14176 #define RECUR(NODE) \
14177 tsubst_copy_and_build (NODE, args, complain, in_decl, \
14178 /*function_p=*/false, \
14179 integral_constant_expression_p)
14180
14181 tree retval, op1;
14182 location_t loc;
14183
14184 if (t == NULL_TREE || t == error_mark_node)
14185 return t;
14186
14187 loc = input_location;
14188 if (EXPR_HAS_LOCATION (t))
14189 input_location = EXPR_LOCATION (t);
14190
14191 /* N3276 decltype magic only applies to calls at the top level or on the
14192 right side of a comma. */
14193 tsubst_flags_t decltype_flag = (complain & tf_decltype);
14194 complain &= ~tf_decltype;
14195
14196 switch (TREE_CODE (t))
14197 {
14198 case USING_DECL:
14199 t = DECL_NAME (t);
14200 /* Fall through. */
14201 case IDENTIFIER_NODE:
14202 {
14203 tree decl;
14204 cp_id_kind idk;
14205 bool non_integral_constant_expression_p;
14206 const char *error_msg;
14207
14208 if (IDENTIFIER_TYPENAME_P (t))
14209 {
14210 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14211 t = mangle_conv_op_name_for_type (new_type);
14212 }
14213
14214 /* Look up the name. */
14215 decl = lookup_name (t);
14216
14217 /* By convention, expressions use ERROR_MARK_NODE to indicate
14218 failure, not NULL_TREE. */
14219 if (decl == NULL_TREE)
14220 decl = error_mark_node;
14221
14222 decl = finish_id_expression (t, decl, NULL_TREE,
14223 &idk,
14224 integral_constant_expression_p,
14225 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx11),
14226 &non_integral_constant_expression_p,
14227 /*template_p=*/false,
14228 /*done=*/true,
14229 /*address_p=*/false,
14230 /*template_arg_p=*/false,
14231 &error_msg,
14232 input_location);
14233 if (error_msg)
14234 error (error_msg);
14235 if (!function_p && identifier_p (decl))
14236 {
14237 if (complain & tf_error)
14238 unqualified_name_lookup_error (decl);
14239 decl = error_mark_node;
14240 }
14241 RETURN (decl);
14242 }
14243
14244 case TEMPLATE_ID_EXPR:
14245 {
14246 tree object;
14247 tree templ = RECUR (TREE_OPERAND (t, 0));
14248 tree targs = TREE_OPERAND (t, 1);
14249
14250 if (targs)
14251 targs = tsubst_template_args (targs, args, complain, in_decl);
14252
14253 if (TREE_CODE (templ) == COMPONENT_REF)
14254 {
14255 object = TREE_OPERAND (templ, 0);
14256 templ = TREE_OPERAND (templ, 1);
14257 }
14258 else
14259 object = NULL_TREE;
14260 templ = lookup_template_function (templ, targs);
14261
14262 if (object)
14263 RETURN (build3 (COMPONENT_REF, TREE_TYPE (templ),
14264 object, templ, NULL_TREE));
14265 else
14266 RETURN (baselink_for_fns (templ));
14267 }
14268
14269 case INDIRECT_REF:
14270 {
14271 tree r = RECUR (TREE_OPERAND (t, 0));
14272
14273 if (REFERENCE_REF_P (t))
14274 {
14275 /* A type conversion to reference type will be enclosed in
14276 such an indirect ref, but the substitution of the cast
14277 will have also added such an indirect ref. */
14278 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
14279 r = convert_from_reference (r);
14280 }
14281 else
14282 r = build_x_indirect_ref (input_location, r, RO_UNARY_STAR,
14283 complain|decltype_flag);
14284 RETURN (r);
14285 }
14286
14287 case NOP_EXPR:
14288 RETURN (build_nop
14289 (tsubst (TREE_TYPE (t), args, complain, in_decl),
14290 RECUR (TREE_OPERAND (t, 0))));
14291
14292 case IMPLICIT_CONV_EXPR:
14293 {
14294 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14295 tree expr = RECUR (TREE_OPERAND (t, 0));
14296 int flags = LOOKUP_IMPLICIT;
14297 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
14298 flags = LOOKUP_NORMAL;
14299 RETURN (perform_implicit_conversion_flags (type, expr, complain,
14300 flags));
14301 }
14302
14303 case CONVERT_EXPR:
14304 RETURN (build1
14305 (CONVERT_EXPR,
14306 tsubst (TREE_TYPE (t), args, complain, in_decl),
14307 RECUR (TREE_OPERAND (t, 0))));
14308
14309 case CAST_EXPR:
14310 case REINTERPRET_CAST_EXPR:
14311 case CONST_CAST_EXPR:
14312 case DYNAMIC_CAST_EXPR:
14313 case STATIC_CAST_EXPR:
14314 {
14315 tree type;
14316 tree op, r = NULL_TREE;
14317
14318 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14319 if (integral_constant_expression_p
14320 && !cast_valid_in_integral_constant_expression_p (type))
14321 {
14322 if (complain & tf_error)
14323 error ("a cast to a type other than an integral or "
14324 "enumeration type cannot appear in a constant-expression");
14325 RETURN (error_mark_node);
14326 }
14327
14328 op = RECUR (TREE_OPERAND (t, 0));
14329
14330 warning_sentinel s(warn_useless_cast);
14331 switch (TREE_CODE (t))
14332 {
14333 case CAST_EXPR:
14334 r = build_functional_cast (type, op, complain);
14335 break;
14336 case REINTERPRET_CAST_EXPR:
14337 r = build_reinterpret_cast (type, op, complain);
14338 break;
14339 case CONST_CAST_EXPR:
14340 r = build_const_cast (type, op, complain);
14341 break;
14342 case DYNAMIC_CAST_EXPR:
14343 r = build_dynamic_cast (type, op, complain);
14344 break;
14345 case STATIC_CAST_EXPR:
14346 r = build_static_cast (type, op, complain);
14347 break;
14348 default:
14349 gcc_unreachable ();
14350 }
14351
14352 RETURN (r);
14353 }
14354
14355 case POSTDECREMENT_EXPR:
14356 case POSTINCREMENT_EXPR:
14357 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14358 args, complain, in_decl);
14359 RETURN (build_x_unary_op (input_location, TREE_CODE (t), op1,
14360 complain|decltype_flag));
14361
14362 case PREDECREMENT_EXPR:
14363 case PREINCREMENT_EXPR:
14364 case NEGATE_EXPR:
14365 case BIT_NOT_EXPR:
14366 case ABS_EXPR:
14367 case TRUTH_NOT_EXPR:
14368 case UNARY_PLUS_EXPR: /* Unary + */
14369 case REALPART_EXPR:
14370 case IMAGPART_EXPR:
14371 RETURN (build_x_unary_op (input_location, TREE_CODE (t),
14372 RECUR (TREE_OPERAND (t, 0)),
14373 complain|decltype_flag));
14374
14375 case FIX_TRUNC_EXPR:
14376 RETURN (cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
14377 0, complain));
14378
14379 case ADDR_EXPR:
14380 op1 = TREE_OPERAND (t, 0);
14381 if (TREE_CODE (op1) == LABEL_DECL)
14382 RETURN (finish_label_address_expr (DECL_NAME (op1),
14383 EXPR_LOCATION (op1)));
14384 if (TREE_CODE (op1) == SCOPE_REF)
14385 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
14386 /*done=*/true, /*address_p=*/true);
14387 else
14388 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
14389 in_decl);
14390 RETURN (build_x_unary_op (input_location, ADDR_EXPR, op1,
14391 complain|decltype_flag));
14392
14393 case PLUS_EXPR:
14394 case MINUS_EXPR:
14395 case MULT_EXPR:
14396 case TRUNC_DIV_EXPR:
14397 case CEIL_DIV_EXPR:
14398 case FLOOR_DIV_EXPR:
14399 case ROUND_DIV_EXPR:
14400 case EXACT_DIV_EXPR:
14401 case BIT_AND_EXPR:
14402 case BIT_IOR_EXPR:
14403 case BIT_XOR_EXPR:
14404 case TRUNC_MOD_EXPR:
14405 case FLOOR_MOD_EXPR:
14406 case TRUTH_ANDIF_EXPR:
14407 case TRUTH_ORIF_EXPR:
14408 case TRUTH_AND_EXPR:
14409 case TRUTH_OR_EXPR:
14410 case RSHIFT_EXPR:
14411 case LSHIFT_EXPR:
14412 case RROTATE_EXPR:
14413 case LROTATE_EXPR:
14414 case EQ_EXPR:
14415 case NE_EXPR:
14416 case MAX_EXPR:
14417 case MIN_EXPR:
14418 case LE_EXPR:
14419 case GE_EXPR:
14420 case LT_EXPR:
14421 case GT_EXPR:
14422 case MEMBER_REF:
14423 case DOTSTAR_EXPR:
14424 {
14425 warning_sentinel s1(warn_type_limits);
14426 warning_sentinel s2(warn_div_by_zero);
14427 tree r = build_x_binary_op
14428 (input_location, TREE_CODE (t),
14429 RECUR (TREE_OPERAND (t, 0)),
14430 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
14431 ? ERROR_MARK
14432 : TREE_CODE (TREE_OPERAND (t, 0))),
14433 RECUR (TREE_OPERAND (t, 1)),
14434 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
14435 ? ERROR_MARK
14436 : TREE_CODE (TREE_OPERAND (t, 1))),
14437 /*overload=*/NULL,
14438 complain|decltype_flag);
14439 if (EXPR_P (r) && TREE_NO_WARNING (t))
14440 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
14441
14442 RETURN (r);
14443 }
14444
14445 case POINTER_PLUS_EXPR:
14446 return fold_build_pointer_plus (RECUR (TREE_OPERAND (t, 0)),
14447 RECUR (TREE_OPERAND (t, 1)));
14448
14449 case SCOPE_REF:
14450 RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
14451 /*address_p=*/false));
14452 case ARRAY_REF:
14453 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14454 args, complain, in_decl);
14455 RETURN (build_x_array_ref (EXPR_LOCATION (t), op1,
14456 RECUR (TREE_OPERAND (t, 1)),
14457 complain|decltype_flag));
14458
14459 case ARRAY_NOTATION_REF:
14460 {
14461 tree start_index, length, stride;
14462 op1 = tsubst_non_call_postfix_expression (ARRAY_NOTATION_ARRAY (t),
14463 args, complain, in_decl);
14464 start_index = RECUR (ARRAY_NOTATION_START (t));
14465 length = RECUR (ARRAY_NOTATION_LENGTH (t));
14466 stride = RECUR (ARRAY_NOTATION_STRIDE (t));
14467 RETURN (build_array_notation_ref (EXPR_LOCATION (t), op1, start_index,
14468 length, stride, TREE_TYPE (op1)));
14469 }
14470 case SIZEOF_EXPR:
14471 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
14472 RETURN (tsubst_copy (t, args, complain, in_decl));
14473 /* Fall through */
14474
14475 case ALIGNOF_EXPR:
14476 {
14477 tree r;
14478
14479 op1 = TREE_OPERAND (t, 0);
14480 if (TREE_CODE (t) == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (t))
14481 op1 = TREE_TYPE (op1);
14482 if (!args)
14483 {
14484 /* When there are no ARGS, we are trying to evaluate a
14485 non-dependent expression from the parser. Trying to do
14486 the substitutions may not work. */
14487 if (!TYPE_P (op1))
14488 op1 = TREE_TYPE (op1);
14489 }
14490 else
14491 {
14492 ++cp_unevaluated_operand;
14493 ++c_inhibit_evaluation_warnings;
14494 if (TYPE_P (op1))
14495 op1 = tsubst (op1, args, complain, in_decl);
14496 else
14497 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
14498 /*function_p=*/false,
14499 /*integral_constant_expression_p=*/
14500 false);
14501 --cp_unevaluated_operand;
14502 --c_inhibit_evaluation_warnings;
14503 }
14504 if (TYPE_P (op1))
14505 r = cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
14506 complain & tf_error);
14507 else
14508 r = cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
14509 complain & tf_error);
14510 if (TREE_CODE (t) == SIZEOF_EXPR && r != error_mark_node)
14511 {
14512 if (TREE_CODE (r) != SIZEOF_EXPR || TYPE_P (op1))
14513 {
14514 if (!processing_template_decl && TYPE_P (op1))
14515 {
14516 r = build_min (SIZEOF_EXPR, size_type_node,
14517 build1 (NOP_EXPR, op1, error_mark_node));
14518 SIZEOF_EXPR_TYPE_P (r) = 1;
14519 }
14520 else
14521 r = build_min (SIZEOF_EXPR, size_type_node, op1);
14522 TREE_SIDE_EFFECTS (r) = 0;
14523 TREE_READONLY (r) = 1;
14524 }
14525 SET_EXPR_LOCATION (r, EXPR_LOCATION (t));
14526 }
14527 RETURN (r);
14528 }
14529
14530 case AT_ENCODE_EXPR:
14531 {
14532 op1 = TREE_OPERAND (t, 0);
14533 ++cp_unevaluated_operand;
14534 ++c_inhibit_evaluation_warnings;
14535 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
14536 /*function_p=*/false,
14537 /*integral_constant_expression_p=*/false);
14538 --cp_unevaluated_operand;
14539 --c_inhibit_evaluation_warnings;
14540 RETURN (objc_build_encode_expr (op1));
14541 }
14542
14543 case NOEXCEPT_EXPR:
14544 op1 = TREE_OPERAND (t, 0);
14545 ++cp_unevaluated_operand;
14546 ++c_inhibit_evaluation_warnings;
14547 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
14548 /*function_p=*/false,
14549 /*integral_constant_expression_p=*/false);
14550 --cp_unevaluated_operand;
14551 --c_inhibit_evaluation_warnings;
14552 RETURN (finish_noexcept_expr (op1, complain));
14553
14554 case MODOP_EXPR:
14555 {
14556 warning_sentinel s(warn_div_by_zero);
14557 tree r = build_x_modify_expr
14558 (EXPR_LOCATION (t),
14559 RECUR (TREE_OPERAND (t, 0)),
14560 TREE_CODE (TREE_OPERAND (t, 1)),
14561 RECUR (TREE_OPERAND (t, 2)),
14562 complain|decltype_flag);
14563 /* TREE_NO_WARNING must be set if either the expression was
14564 parenthesized or it uses an operator such as >>= rather
14565 than plain assignment. In the former case, it was already
14566 set and must be copied. In the latter case,
14567 build_x_modify_expr sets it and it must not be reset
14568 here. */
14569 if (TREE_NO_WARNING (t))
14570 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
14571
14572 RETURN (r);
14573 }
14574
14575 case ARROW_EXPR:
14576 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14577 args, complain, in_decl);
14578 /* Remember that there was a reference to this entity. */
14579 if (DECL_P (op1))
14580 mark_used (op1);
14581 RETURN (build_x_arrow (input_location, op1, complain));
14582
14583 case NEW_EXPR:
14584 {
14585 tree placement = RECUR (TREE_OPERAND (t, 0));
14586 tree init = RECUR (TREE_OPERAND (t, 3));
14587 vec<tree, va_gc> *placement_vec;
14588 vec<tree, va_gc> *init_vec;
14589 tree ret;
14590
14591 if (placement == NULL_TREE)
14592 placement_vec = NULL;
14593 else
14594 {
14595 placement_vec = make_tree_vector ();
14596 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
14597 vec_safe_push (placement_vec, TREE_VALUE (placement));
14598 }
14599
14600 /* If there was an initializer in the original tree, but it
14601 instantiated to an empty list, then we should pass a
14602 non-NULL empty vector to tell build_new that it was an
14603 empty initializer() rather than no initializer. This can
14604 only happen when the initializer is a pack expansion whose
14605 parameter packs are of length zero. */
14606 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
14607 init_vec = NULL;
14608 else
14609 {
14610 init_vec = make_tree_vector ();
14611 if (init == void_zero_node)
14612 gcc_assert (init_vec != NULL);
14613 else
14614 {
14615 for (; init != NULL_TREE; init = TREE_CHAIN (init))
14616 vec_safe_push (init_vec, TREE_VALUE (init));
14617 }
14618 }
14619
14620 ret = build_new (&placement_vec,
14621 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
14622 RECUR (TREE_OPERAND (t, 2)),
14623 &init_vec,
14624 NEW_EXPR_USE_GLOBAL (t),
14625 complain);
14626
14627 if (placement_vec != NULL)
14628 release_tree_vector (placement_vec);
14629 if (init_vec != NULL)
14630 release_tree_vector (init_vec);
14631
14632 RETURN (ret);
14633 }
14634
14635 case DELETE_EXPR:
14636 RETURN (delete_sanity
14637 (RECUR (TREE_OPERAND (t, 0)),
14638 RECUR (TREE_OPERAND (t, 1)),
14639 DELETE_EXPR_USE_VEC (t),
14640 DELETE_EXPR_USE_GLOBAL (t),
14641 complain));
14642
14643 case COMPOUND_EXPR:
14644 {
14645 tree op0 = tsubst_copy_and_build (TREE_OPERAND (t, 0), args,
14646 complain & ~tf_decltype, in_decl,
14647 /*function_p=*/false,
14648 integral_constant_expression_p);
14649 RETURN (build_x_compound_expr (EXPR_LOCATION (t),
14650 op0,
14651 RECUR (TREE_OPERAND (t, 1)),
14652 complain|decltype_flag));
14653 }
14654
14655 case CALL_EXPR:
14656 {
14657 tree function;
14658 vec<tree, va_gc> *call_args;
14659 unsigned int nargs, i;
14660 bool qualified_p;
14661 bool koenig_p;
14662 tree ret;
14663
14664 function = CALL_EXPR_FN (t);
14665 /* When we parsed the expression, we determined whether or
14666 not Koenig lookup should be performed. */
14667 koenig_p = KOENIG_LOOKUP_P (t);
14668 if (TREE_CODE (function) == SCOPE_REF)
14669 {
14670 qualified_p = true;
14671 function = tsubst_qualified_id (function, args, complain, in_decl,
14672 /*done=*/false,
14673 /*address_p=*/false);
14674 }
14675 else if (koenig_p && identifier_p (function))
14676 {
14677 /* Do nothing; calling tsubst_copy_and_build on an identifier
14678 would incorrectly perform unqualified lookup again.
14679
14680 Note that we can also have an IDENTIFIER_NODE if the earlier
14681 unqualified lookup found a member function; in that case
14682 koenig_p will be false and we do want to do the lookup
14683 again to find the instantiated member function.
14684
14685 FIXME but doing that causes c++/15272, so we need to stop
14686 using IDENTIFIER_NODE in that situation. */
14687 qualified_p = false;
14688 }
14689 else
14690 {
14691 if (TREE_CODE (function) == COMPONENT_REF)
14692 {
14693 tree op = TREE_OPERAND (function, 1);
14694
14695 qualified_p = (TREE_CODE (op) == SCOPE_REF
14696 || (BASELINK_P (op)
14697 && BASELINK_QUALIFIED_P (op)));
14698 }
14699 else
14700 qualified_p = false;
14701
14702 if (TREE_CODE (function) == ADDR_EXPR
14703 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
14704 /* Avoid error about taking the address of a constructor. */
14705 function = TREE_OPERAND (function, 0);
14706
14707 function = tsubst_copy_and_build (function, args, complain,
14708 in_decl,
14709 !qualified_p,
14710 integral_constant_expression_p);
14711
14712 if (BASELINK_P (function))
14713 qualified_p = true;
14714 }
14715
14716 nargs = call_expr_nargs (t);
14717 call_args = make_tree_vector ();
14718 for (i = 0; i < nargs; ++i)
14719 {
14720 tree arg = CALL_EXPR_ARG (t, i);
14721
14722 if (!PACK_EXPANSION_P (arg))
14723 vec_safe_push (call_args, RECUR (CALL_EXPR_ARG (t, i)));
14724 else
14725 {
14726 /* Expand the pack expansion and push each entry onto
14727 CALL_ARGS. */
14728 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
14729 if (TREE_CODE (arg) == TREE_VEC)
14730 {
14731 unsigned int len, j;
14732
14733 len = TREE_VEC_LENGTH (arg);
14734 for (j = 0; j < len; ++j)
14735 {
14736 tree value = TREE_VEC_ELT (arg, j);
14737 if (value != NULL_TREE)
14738 value = convert_from_reference (value);
14739 vec_safe_push (call_args, value);
14740 }
14741 }
14742 else
14743 {
14744 /* A partial substitution. Add one entry. */
14745 vec_safe_push (call_args, arg);
14746 }
14747 }
14748 }
14749
14750 /* We do not perform argument-dependent lookup if normal
14751 lookup finds a non-function, in accordance with the
14752 expected resolution of DR 218. */
14753 if (koenig_p
14754 && ((is_overloaded_fn (function)
14755 /* If lookup found a member function, the Koenig lookup is
14756 not appropriate, even if an unqualified-name was used
14757 to denote the function. */
14758 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
14759 || identifier_p (function))
14760 /* Only do this when substitution turns a dependent call
14761 into a non-dependent call. */
14762 && type_dependent_expression_p_push (t)
14763 && !any_type_dependent_arguments_p (call_args))
14764 function = perform_koenig_lookup (function, call_args, tf_none);
14765
14766 if (identifier_p (function)
14767 && !any_type_dependent_arguments_p (call_args))
14768 {
14769 if (koenig_p && (complain & tf_warning_or_error))
14770 {
14771 /* For backwards compatibility and good diagnostics, try
14772 the unqualified lookup again if we aren't in SFINAE
14773 context. */
14774 tree unq = (tsubst_copy_and_build
14775 (function, args, complain, in_decl, true,
14776 integral_constant_expression_p));
14777 if (unq == error_mark_node)
14778 RETURN (error_mark_node);
14779
14780 if (unq != function)
14781 {
14782 tree fn = unq;
14783 if (INDIRECT_REF_P (fn))
14784 fn = TREE_OPERAND (fn, 0);
14785 if (TREE_CODE (fn) == COMPONENT_REF)
14786 fn = TREE_OPERAND (fn, 1);
14787 if (is_overloaded_fn (fn))
14788 fn = get_first_fn (fn);
14789 if (permerror (EXPR_LOC_OR_LOC (t, input_location),
14790 "%qD was not declared in this scope, "
14791 "and no declarations were found by "
14792 "argument-dependent lookup at the point "
14793 "of instantiation", function))
14794 {
14795 if (!DECL_P (fn))
14796 /* Can't say anything more. */;
14797 else if (DECL_CLASS_SCOPE_P (fn))
14798 {
14799 location_t loc = EXPR_LOC_OR_LOC (t,
14800 input_location);
14801 inform (loc,
14802 "declarations in dependent base %qT are "
14803 "not found by unqualified lookup",
14804 DECL_CLASS_CONTEXT (fn));
14805 if (current_class_ptr)
14806 inform (loc,
14807 "use %<this->%D%> instead", function);
14808 else
14809 inform (loc,
14810 "use %<%T::%D%> instead",
14811 current_class_name, function);
14812 }
14813 else
14814 inform (0, "%q+D declared here, later in the "
14815 "translation unit", fn);
14816 }
14817 function = unq;
14818 }
14819 }
14820 if (identifier_p (function))
14821 {
14822 if (complain & tf_error)
14823 unqualified_name_lookup_error (function);
14824 release_tree_vector (call_args);
14825 RETURN (error_mark_node);
14826 }
14827 }
14828
14829 /* Remember that there was a reference to this entity. */
14830 if (DECL_P (function))
14831 mark_used (function);
14832
14833 /* Put back tf_decltype for the actual call. */
14834 complain |= decltype_flag;
14835
14836 if (TREE_CODE (function) == OFFSET_REF)
14837 ret = build_offset_ref_call_from_tree (function, &call_args,
14838 complain);
14839 else if (TREE_CODE (function) == COMPONENT_REF)
14840 {
14841 tree instance = TREE_OPERAND (function, 0);
14842 tree fn = TREE_OPERAND (function, 1);
14843
14844 if (processing_template_decl
14845 && (type_dependent_expression_p (instance)
14846 || (!BASELINK_P (fn)
14847 && TREE_CODE (fn) != FIELD_DECL)
14848 || type_dependent_expression_p (fn)
14849 || any_type_dependent_arguments_p (call_args)))
14850 ret = build_nt_call_vec (function, call_args);
14851 else if (!BASELINK_P (fn))
14852 ret = finish_call_expr (function, &call_args,
14853 /*disallow_virtual=*/false,
14854 /*koenig_p=*/false,
14855 complain);
14856 else
14857 ret = (build_new_method_call
14858 (instance, fn,
14859 &call_args, NULL_TREE,
14860 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
14861 /*fn_p=*/NULL,
14862 complain));
14863 }
14864 else
14865 ret = finish_call_expr (function, &call_args,
14866 /*disallow_virtual=*/qualified_p,
14867 koenig_p,
14868 complain);
14869
14870 release_tree_vector (call_args);
14871
14872 RETURN (ret);
14873 }
14874
14875 case COND_EXPR:
14876 {
14877 tree cond = RECUR (TREE_OPERAND (t, 0));
14878 tree exp1, exp2;
14879
14880 if (TREE_CODE (cond) == INTEGER_CST)
14881 {
14882 if (integer_zerop (cond))
14883 {
14884 ++c_inhibit_evaluation_warnings;
14885 exp1 = RECUR (TREE_OPERAND (t, 1));
14886 --c_inhibit_evaluation_warnings;
14887 exp2 = RECUR (TREE_OPERAND (t, 2));
14888 }
14889 else
14890 {
14891 exp1 = RECUR (TREE_OPERAND (t, 1));
14892 ++c_inhibit_evaluation_warnings;
14893 exp2 = RECUR (TREE_OPERAND (t, 2));
14894 --c_inhibit_evaluation_warnings;
14895 }
14896 }
14897 else
14898 {
14899 exp1 = RECUR (TREE_OPERAND (t, 1));
14900 exp2 = RECUR (TREE_OPERAND (t, 2));
14901 }
14902
14903 RETURN (build_x_conditional_expr (EXPR_LOCATION (t),
14904 cond, exp1, exp2, complain));
14905 }
14906
14907 case PSEUDO_DTOR_EXPR:
14908 RETURN (finish_pseudo_destructor_expr
14909 (RECUR (TREE_OPERAND (t, 0)),
14910 RECUR (TREE_OPERAND (t, 1)),
14911 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl),
14912 input_location));
14913
14914 case TREE_LIST:
14915 {
14916 tree purpose, value, chain;
14917
14918 if (t == void_list_node)
14919 RETURN (t);
14920
14921 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
14922 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
14923 {
14924 /* We have pack expansions, so expand those and
14925 create a new list out of it. */
14926 tree purposevec = NULL_TREE;
14927 tree valuevec = NULL_TREE;
14928 tree chain;
14929 int i, len = -1;
14930
14931 /* Expand the argument expressions. */
14932 if (TREE_PURPOSE (t))
14933 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
14934 complain, in_decl);
14935 if (TREE_VALUE (t))
14936 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
14937 complain, in_decl);
14938
14939 /* Build the rest of the list. */
14940 chain = TREE_CHAIN (t);
14941 if (chain && chain != void_type_node)
14942 chain = RECUR (chain);
14943
14944 /* Determine the number of arguments. */
14945 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
14946 {
14947 len = TREE_VEC_LENGTH (purposevec);
14948 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
14949 }
14950 else if (TREE_CODE (valuevec) == TREE_VEC)
14951 len = TREE_VEC_LENGTH (valuevec);
14952 else
14953 {
14954 /* Since we only performed a partial substitution into
14955 the argument pack, we only RETURN (a single list
14956 node. */
14957 if (purposevec == TREE_PURPOSE (t)
14958 && valuevec == TREE_VALUE (t)
14959 && chain == TREE_CHAIN (t))
14960 RETURN (t);
14961
14962 RETURN (tree_cons (purposevec, valuevec, chain));
14963 }
14964
14965 /* Convert the argument vectors into a TREE_LIST */
14966 i = len;
14967 while (i > 0)
14968 {
14969 /* Grab the Ith values. */
14970 i--;
14971 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14972 : NULL_TREE;
14973 value
14974 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14975 : NULL_TREE;
14976
14977 /* Build the list (backwards). */
14978 chain = tree_cons (purpose, value, chain);
14979 }
14980
14981 RETURN (chain);
14982 }
14983
14984 purpose = TREE_PURPOSE (t);
14985 if (purpose)
14986 purpose = RECUR (purpose);
14987 value = TREE_VALUE (t);
14988 if (value)
14989 value = RECUR (value);
14990 chain = TREE_CHAIN (t);
14991 if (chain && chain != void_type_node)
14992 chain = RECUR (chain);
14993 if (purpose == TREE_PURPOSE (t)
14994 && value == TREE_VALUE (t)
14995 && chain == TREE_CHAIN (t))
14996 RETURN (t);
14997 RETURN (tree_cons (purpose, value, chain));
14998 }
14999
15000 case COMPONENT_REF:
15001 {
15002 tree object;
15003 tree object_type;
15004 tree member;
15005 tree r;
15006
15007 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
15008 args, complain, in_decl);
15009 /* Remember that there was a reference to this entity. */
15010 if (DECL_P (object))
15011 mark_used (object);
15012 object_type = TREE_TYPE (object);
15013
15014 member = TREE_OPERAND (t, 1);
15015 if (BASELINK_P (member))
15016 member = tsubst_baselink (member,
15017 non_reference (TREE_TYPE (object)),
15018 args, complain, in_decl);
15019 else
15020 member = tsubst_copy (member, args, complain, in_decl);
15021 if (member == error_mark_node)
15022 RETURN (error_mark_node);
15023
15024 if (type_dependent_expression_p (object))
15025 /* We can't do much here. */;
15026 else if (!CLASS_TYPE_P (object_type))
15027 {
15028 if (scalarish_type_p (object_type))
15029 {
15030 tree s = NULL_TREE;
15031 tree dtor = member;
15032
15033 if (TREE_CODE (dtor) == SCOPE_REF)
15034 {
15035 s = TREE_OPERAND (dtor, 0);
15036 dtor = TREE_OPERAND (dtor, 1);
15037 }
15038 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
15039 {
15040 dtor = TREE_OPERAND (dtor, 0);
15041 if (TYPE_P (dtor))
15042 RETURN (finish_pseudo_destructor_expr
15043 (object, s, dtor, input_location));
15044 }
15045 }
15046 }
15047 else if (TREE_CODE (member) == SCOPE_REF
15048 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
15049 {
15050 /* Lookup the template functions now that we know what the
15051 scope is. */
15052 tree scope = TREE_OPERAND (member, 0);
15053 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
15054 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
15055 member = lookup_qualified_name (scope, tmpl,
15056 /*is_type_p=*/false,
15057 /*complain=*/false);
15058 if (BASELINK_P (member))
15059 {
15060 BASELINK_FUNCTIONS (member)
15061 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
15062 args);
15063 member = (adjust_result_of_qualified_name_lookup
15064 (member, BINFO_TYPE (BASELINK_BINFO (member)),
15065 object_type));
15066 }
15067 else
15068 {
15069 qualified_name_lookup_error (scope, tmpl, member,
15070 input_location);
15071 RETURN (error_mark_node);
15072 }
15073 }
15074 else if (TREE_CODE (member) == SCOPE_REF
15075 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
15076 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
15077 {
15078 if (complain & tf_error)
15079 {
15080 if (TYPE_P (TREE_OPERAND (member, 0)))
15081 error ("%qT is not a class or namespace",
15082 TREE_OPERAND (member, 0));
15083 else
15084 error ("%qD is not a class or namespace",
15085 TREE_OPERAND (member, 0));
15086 }
15087 RETURN (error_mark_node);
15088 }
15089 else if (TREE_CODE (member) == FIELD_DECL)
15090 {
15091 r = finish_non_static_data_member (member, object, NULL_TREE);
15092 if (TREE_CODE (r) == COMPONENT_REF)
15093 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
15094 RETURN (r);
15095 }
15096
15097 r = finish_class_member_access_expr (object, member,
15098 /*template_p=*/false,
15099 complain);
15100 if (TREE_CODE (r) == COMPONENT_REF)
15101 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
15102 RETURN (r);
15103 }
15104
15105 case THROW_EXPR:
15106 RETURN (build_throw
15107 (RECUR (TREE_OPERAND (t, 0))));
15108
15109 case CONSTRUCTOR:
15110 {
15111 vec<constructor_elt, va_gc> *n;
15112 constructor_elt *ce;
15113 unsigned HOST_WIDE_INT idx;
15114 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
15115 bool process_index_p;
15116 int newlen;
15117 bool need_copy_p = false;
15118 tree r;
15119
15120 if (type == error_mark_node)
15121 RETURN (error_mark_node);
15122
15123 /* digest_init will do the wrong thing if we let it. */
15124 if (type && TYPE_PTRMEMFUNC_P (type))
15125 RETURN (t);
15126
15127 /* We do not want to process the index of aggregate
15128 initializers as they are identifier nodes which will be
15129 looked up by digest_init. */
15130 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
15131
15132 n = vec_safe_copy (CONSTRUCTOR_ELTS (t));
15133 newlen = vec_safe_length (n);
15134 FOR_EACH_VEC_SAFE_ELT (n, idx, ce)
15135 {
15136 if (ce->index && process_index_p
15137 /* An identifier index is looked up in the type
15138 being initialized, not the current scope. */
15139 && TREE_CODE (ce->index) != IDENTIFIER_NODE)
15140 ce->index = RECUR (ce->index);
15141
15142 if (PACK_EXPANSION_P (ce->value))
15143 {
15144 /* Substitute into the pack expansion. */
15145 ce->value = tsubst_pack_expansion (ce->value, args, complain,
15146 in_decl);
15147
15148 if (ce->value == error_mark_node
15149 || PACK_EXPANSION_P (ce->value))
15150 ;
15151 else if (TREE_VEC_LENGTH (ce->value) == 1)
15152 /* Just move the argument into place. */
15153 ce->value = TREE_VEC_ELT (ce->value, 0);
15154 else
15155 {
15156 /* Update the length of the final CONSTRUCTOR
15157 arguments vector, and note that we will need to
15158 copy.*/
15159 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
15160 need_copy_p = true;
15161 }
15162 }
15163 else
15164 ce->value = RECUR (ce->value);
15165 }
15166
15167 if (need_copy_p)
15168 {
15169 vec<constructor_elt, va_gc> *old_n = n;
15170
15171 vec_alloc (n, newlen);
15172 FOR_EACH_VEC_ELT (*old_n, idx, ce)
15173 {
15174 if (TREE_CODE (ce->value) == TREE_VEC)
15175 {
15176 int i, len = TREE_VEC_LENGTH (ce->value);
15177 for (i = 0; i < len; ++i)
15178 CONSTRUCTOR_APPEND_ELT (n, 0,
15179 TREE_VEC_ELT (ce->value, i));
15180 }
15181 else
15182 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
15183 }
15184 }
15185
15186 r = build_constructor (init_list_type_node, n);
15187 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
15188
15189 if (TREE_HAS_CONSTRUCTOR (t))
15190 RETURN (finish_compound_literal (type, r, complain));
15191
15192 TREE_TYPE (r) = type;
15193 RETURN (r);
15194 }
15195
15196 case TYPEID_EXPR:
15197 {
15198 tree operand_0 = TREE_OPERAND (t, 0);
15199 if (TYPE_P (operand_0))
15200 {
15201 operand_0 = tsubst (operand_0, args, complain, in_decl);
15202 RETURN (get_typeid (operand_0, complain));
15203 }
15204 else
15205 {
15206 operand_0 = RECUR (operand_0);
15207 RETURN (build_typeid (operand_0, complain));
15208 }
15209 }
15210
15211 case VAR_DECL:
15212 if (!args)
15213 RETURN (t);
15214 else if (DECL_PACK_P (t))
15215 {
15216 /* We don't build decls for an instantiation of a
15217 variadic capture proxy, we instantiate the elements
15218 when needed. */
15219 gcc_assert (DECL_HAS_VALUE_EXPR_P (t));
15220 return RECUR (DECL_VALUE_EXPR (t));
15221 }
15222 /* Fall through */
15223
15224 case PARM_DECL:
15225 {
15226 tree r = tsubst_copy (t, args, complain, in_decl);
15227 if (TREE_CODE (r) == VAR_DECL
15228 && !processing_template_decl
15229 && !cp_unevaluated_operand
15230 && DECL_THREAD_LOCAL_P (r))
15231 {
15232 if (tree wrap = get_tls_wrapper_fn (r))
15233 /* Replace an evaluated use of the thread_local variable with
15234 a call to its wrapper. */
15235 r = build_cxx_call (wrap, 0, NULL, tf_warning_or_error);
15236 }
15237
15238 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
15239 /* If the original type was a reference, we'll be wrapped in
15240 the appropriate INDIRECT_REF. */
15241 r = convert_from_reference (r);
15242 RETURN (r);
15243 }
15244
15245 case VA_ARG_EXPR:
15246 RETURN (build_x_va_arg (EXPR_LOCATION (t),
15247 RECUR (TREE_OPERAND (t, 0)),
15248 tsubst (TREE_TYPE (t), args, complain, in_decl)));
15249
15250 case OFFSETOF_EXPR:
15251 RETURN (finish_offsetof (RECUR (TREE_OPERAND (t, 0))));
15252
15253 case TRAIT_EXPR:
15254 {
15255 tree type1 = tsubst (TRAIT_EXPR_TYPE1 (t), args,
15256 complain, in_decl);
15257
15258 tree type2 = TRAIT_EXPR_TYPE2 (t);
15259 if (type2)
15260 type2 = tsubst (type2, args, complain, in_decl);
15261
15262 RETURN (finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2));
15263 }
15264
15265 case STMT_EXPR:
15266 {
15267 tree old_stmt_expr = cur_stmt_expr;
15268 tree stmt_expr = begin_stmt_expr ();
15269
15270 cur_stmt_expr = stmt_expr;
15271 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
15272 integral_constant_expression_p);
15273 stmt_expr = finish_stmt_expr (stmt_expr, false);
15274 cur_stmt_expr = old_stmt_expr;
15275
15276 /* If the resulting list of expression statement is empty,
15277 fold it further into void_zero_node. */
15278 if (empty_expr_stmt_p (stmt_expr))
15279 stmt_expr = void_zero_node;
15280
15281 RETURN (stmt_expr);
15282 }
15283
15284 case LAMBDA_EXPR:
15285 {
15286 tree r = build_lambda_expr ();
15287
15288 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
15289 LAMBDA_EXPR_CLOSURE (r) = type;
15290 CLASSTYPE_LAMBDA_EXPR (type) = r;
15291
15292 LAMBDA_EXPR_LOCATION (r)
15293 = LAMBDA_EXPR_LOCATION (t);
15294 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
15295 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
15296 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
15297 LAMBDA_EXPR_DISCRIMINATOR (r)
15298 = (LAMBDA_EXPR_DISCRIMINATOR (t));
15299 /* For a function scope, we want to use tsubst so that we don't
15300 complain about referring to an auto function before its return
15301 type has been deduced. Otherwise, we want to use tsubst_copy so
15302 that we look up the existing field/parameter/variable rather
15303 than build a new one. */
15304 tree scope = LAMBDA_EXPR_EXTRA_SCOPE (t);
15305 if (scope && TREE_CODE (scope) == FUNCTION_DECL)
15306 scope = tsubst (scope, args, complain, in_decl);
15307 else if (scope && TREE_CODE (scope) == PARM_DECL)
15308 {
15309 /* Look up the parameter we want directly, as tsubst_copy
15310 doesn't do what we need. */
15311 tree fn = tsubst (DECL_CONTEXT (scope), args, complain, in_decl);
15312 tree parm = FUNCTION_FIRST_USER_PARM (fn);
15313 while (DECL_PARM_INDEX (parm) != DECL_PARM_INDEX (scope))
15314 parm = DECL_CHAIN (parm);
15315 scope = parm;
15316 /* FIXME Work around the parm not having DECL_CONTEXT set. */
15317 if (DECL_CONTEXT (scope) == NULL_TREE)
15318 DECL_CONTEXT (scope) = fn;
15319 }
15320 else
15321 scope = RECUR (scope);
15322 LAMBDA_EXPR_EXTRA_SCOPE (r) = scope;
15323 LAMBDA_EXPR_RETURN_TYPE (r)
15324 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
15325
15326 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
15327 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
15328
15329 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
15330 determine_visibility (TYPE_NAME (type));
15331 /* Now that we know visibility, instantiate the type so we have a
15332 declaration of the op() for later calls to lambda_function. */
15333 complete_type (type);
15334
15335 LAMBDA_EXPR_THIS_CAPTURE (r) = NULL_TREE;
15336
15337 RETURN (build_lambda_object (r));
15338 }
15339
15340 case TARGET_EXPR:
15341 /* We can get here for a constant initializer of non-dependent type.
15342 FIXME stop folding in cp_parser_initializer_clause. */
15343 {
15344 tree r = get_target_expr_sfinae (RECUR (TARGET_EXPR_INITIAL (t)),
15345 complain);
15346 RETURN (r);
15347 }
15348
15349 case TRANSACTION_EXPR:
15350 RETURN (tsubst_expr(t, args, complain, in_decl,
15351 integral_constant_expression_p));
15352
15353 case PAREN_EXPR:
15354 RETURN (finish_parenthesized_expr (RECUR (TREE_OPERAND (t, 0))));
15355
15356 case VEC_PERM_EXPR:
15357 RETURN (build_x_vec_perm_expr (input_location,
15358 RECUR (TREE_OPERAND (t, 0)),
15359 RECUR (TREE_OPERAND (t, 1)),
15360 RECUR (TREE_OPERAND (t, 2)),
15361 complain));
15362
15363 default:
15364 /* Handle Objective-C++ constructs, if appropriate. */
15365 {
15366 tree subst
15367 = objcp_tsubst_copy_and_build (t, args, complain,
15368 in_decl, /*function_p=*/false);
15369 if (subst)
15370 RETURN (subst);
15371 }
15372 RETURN (tsubst_copy (t, args, complain, in_decl));
15373 }
15374
15375 #undef RECUR
15376 #undef RETURN
15377 out:
15378 input_location = loc;
15379 return retval;
15380 }
15381
15382 /* Verify that the instantiated ARGS are valid. For type arguments,
15383 make sure that the type's linkage is ok. For non-type arguments,
15384 make sure they are constants if they are integral or enumerations.
15385 Emit an error under control of COMPLAIN, and return TRUE on error. */
15386
15387 static bool
check_instantiated_arg(tree tmpl,tree t,tsubst_flags_t complain)15388 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
15389 {
15390 if (dependent_template_arg_p (t))
15391 return false;
15392 if (ARGUMENT_PACK_P (t))
15393 {
15394 tree vec = ARGUMENT_PACK_ARGS (t);
15395 int len = TREE_VEC_LENGTH (vec);
15396 bool result = false;
15397 int i;
15398
15399 for (i = 0; i < len; ++i)
15400 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
15401 result = true;
15402 return result;
15403 }
15404 else if (TYPE_P (t))
15405 {
15406 /* [basic.link]: A name with no linkage (notably, the name
15407 of a class or enumeration declared in a local scope)
15408 shall not be used to declare an entity with linkage.
15409 This implies that names with no linkage cannot be used as
15410 template arguments
15411
15412 DR 757 relaxes this restriction for C++0x. */
15413 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
15414 : no_linkage_check (t, /*relaxed_p=*/false));
15415
15416 if (nt)
15417 {
15418 /* DR 488 makes use of a type with no linkage cause
15419 type deduction to fail. */
15420 if (complain & tf_error)
15421 {
15422 if (TYPE_ANONYMOUS_P (nt))
15423 error ("%qT is/uses anonymous type", t);
15424 else
15425 error ("template argument for %qD uses local type %qT",
15426 tmpl, t);
15427 }
15428 return true;
15429 }
15430 /* In order to avoid all sorts of complications, we do not
15431 allow variably-modified types as template arguments. */
15432 else if (variably_modified_type_p (t, NULL_TREE))
15433 {
15434 if (complain & tf_error)
15435 error ("%qT is a variably modified type", t);
15436 return true;
15437 }
15438 }
15439 /* Class template and alias template arguments should be OK. */
15440 else if (DECL_TYPE_TEMPLATE_P (t))
15441 ;
15442 /* A non-type argument of integral or enumerated type must be a
15443 constant. */
15444 else if (TREE_TYPE (t)
15445 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
15446 && !TREE_CONSTANT (t))
15447 {
15448 if (complain & tf_error)
15449 error ("integral expression %qE is not constant", t);
15450 return true;
15451 }
15452 return false;
15453 }
15454
15455 static bool
check_instantiated_args(tree tmpl,tree args,tsubst_flags_t complain)15456 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
15457 {
15458 int ix, len = DECL_NTPARMS (tmpl);
15459 bool result = false;
15460
15461 for (ix = 0; ix != len; ix++)
15462 {
15463 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
15464 result = true;
15465 }
15466 if (result && (complain & tf_error))
15467 error (" trying to instantiate %qD", tmpl);
15468 return result;
15469 }
15470
15471 /* We're out of SFINAE context now, so generate diagnostics for the access
15472 errors we saw earlier when instantiating D from TMPL and ARGS. */
15473
15474 static void
recheck_decl_substitution(tree d,tree tmpl,tree args)15475 recheck_decl_substitution (tree d, tree tmpl, tree args)
15476 {
15477 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
15478 tree type = TREE_TYPE (pattern);
15479 location_t loc = input_location;
15480
15481 push_access_scope (d);
15482 push_deferring_access_checks (dk_no_deferred);
15483 input_location = DECL_SOURCE_LOCATION (pattern);
15484 tsubst (type, args, tf_warning_or_error, d);
15485 input_location = loc;
15486 pop_deferring_access_checks ();
15487 pop_access_scope (d);
15488 }
15489
15490 /* Instantiate the indicated variable, function, or alias template TMPL with
15491 the template arguments in TARG_PTR. */
15492
15493 static tree
instantiate_template_1(tree tmpl,tree orig_args,tsubst_flags_t complain)15494 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
15495 {
15496 tree targ_ptr = orig_args;
15497 tree fndecl;
15498 tree gen_tmpl;
15499 tree spec;
15500 bool access_ok = true;
15501
15502 if (tmpl == error_mark_node)
15503 return error_mark_node;
15504
15505 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
15506
15507 /* If this function is a clone, handle it specially. */
15508 if (DECL_CLONED_FUNCTION_P (tmpl))
15509 {
15510 tree spec;
15511 tree clone;
15512
15513 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
15514 DECL_CLONED_FUNCTION. */
15515 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
15516 targ_ptr, complain);
15517 if (spec == error_mark_node)
15518 return error_mark_node;
15519
15520 /* Look for the clone. */
15521 FOR_EACH_CLONE (clone, spec)
15522 if (DECL_NAME (clone) == DECL_NAME (tmpl))
15523 return clone;
15524 /* We should always have found the clone by now. */
15525 gcc_unreachable ();
15526 return NULL_TREE;
15527 }
15528
15529 if (targ_ptr == error_mark_node)
15530 return error_mark_node;
15531
15532 /* Check to see if we already have this specialization. */
15533 gen_tmpl = most_general_template (tmpl);
15534 if (tmpl != gen_tmpl)
15535 /* The TMPL is a partial instantiation. To get a full set of
15536 arguments we must add the arguments used to perform the
15537 partial instantiation. */
15538 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
15539 targ_ptr);
15540
15541 /* It would be nice to avoid hashing here and then again in tsubst_decl,
15542 but it doesn't seem to be on the hot path. */
15543 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
15544
15545 gcc_assert (tmpl == gen_tmpl
15546 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
15547 == spec)
15548 || fndecl == NULL_TREE);
15549
15550 if (spec != NULL_TREE)
15551 {
15552 if (FNDECL_HAS_ACCESS_ERRORS (spec))
15553 {
15554 if (complain & tf_error)
15555 recheck_decl_substitution (spec, gen_tmpl, targ_ptr);
15556 return error_mark_node;
15557 }
15558 return spec;
15559 }
15560
15561 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
15562 complain))
15563 return error_mark_node;
15564
15565 /* We are building a FUNCTION_DECL, during which the access of its
15566 parameters and return types have to be checked. However this
15567 FUNCTION_DECL which is the desired context for access checking
15568 is not built yet. We solve this chicken-and-egg problem by
15569 deferring all checks until we have the FUNCTION_DECL. */
15570 push_deferring_access_checks (dk_deferred);
15571
15572 /* Instantiation of the function happens in the context of the function
15573 template, not the context of the overload resolution we're doing. */
15574 push_to_top_level ();
15575 /* If there are dependent arguments, e.g. because we're doing partial
15576 ordering, make sure processing_template_decl stays set. */
15577 if (uses_template_parms (targ_ptr))
15578 ++processing_template_decl;
15579 if (DECL_CLASS_SCOPE_P (gen_tmpl))
15580 {
15581 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
15582 complain, gen_tmpl);
15583 push_nested_class (ctx);
15584 }
15585 /* Substitute template parameters to obtain the specialization. */
15586 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
15587 targ_ptr, complain, gen_tmpl);
15588 if (DECL_CLASS_SCOPE_P (gen_tmpl))
15589 pop_nested_class ();
15590 pop_from_top_level ();
15591
15592 if (fndecl == error_mark_node)
15593 {
15594 pop_deferring_access_checks ();
15595 return error_mark_node;
15596 }
15597
15598 /* The DECL_TI_TEMPLATE should always be the immediate parent
15599 template, not the most general template. */
15600 DECL_TI_TEMPLATE (fndecl) = tmpl;
15601
15602 /* Now we know the specialization, compute access previously
15603 deferred. */
15604 push_access_scope (fndecl);
15605 if (!perform_deferred_access_checks (complain))
15606 access_ok = false;
15607 pop_access_scope (fndecl);
15608 pop_deferring_access_checks ();
15609
15610 /* If we've just instantiated the main entry point for a function,
15611 instantiate all the alternate entry points as well. We do this
15612 by cloning the instantiation of the main entry point, not by
15613 instantiating the template clones. */
15614 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
15615 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
15616
15617 if (!access_ok)
15618 {
15619 if (!(complain & tf_error))
15620 {
15621 /* Remember to reinstantiate when we're out of SFINAE so the user
15622 can see the errors. */
15623 FNDECL_HAS_ACCESS_ERRORS (fndecl) = true;
15624 }
15625 return error_mark_node;
15626 }
15627 return fndecl;
15628 }
15629
15630 /* Wrapper for instantiate_template_1. */
15631
15632 tree
instantiate_template(tree tmpl,tree orig_args,tsubst_flags_t complain)15633 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
15634 {
15635 tree ret;
15636 timevar_push (TV_TEMPLATE_INST);
15637 ret = instantiate_template_1 (tmpl, orig_args, complain);
15638 timevar_pop (TV_TEMPLATE_INST);
15639 return ret;
15640 }
15641
15642 /* Instantiate the alias template TMPL with ARGS. Also push a template
15643 instantiation level, which instantiate_template doesn't do because
15644 functions and variables have sufficient context established by the
15645 callers. */
15646
15647 static tree
instantiate_alias_template(tree tmpl,tree args,tsubst_flags_t complain)15648 instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain)
15649 {
15650 struct pending_template *old_last_pend = last_pending_template;
15651 struct tinst_level *old_error_tinst = last_error_tinst_level;
15652 if (tmpl == error_mark_node || args == error_mark_node)
15653 return error_mark_node;
15654 tree tinst = build_tree_list (tmpl, args);
15655 if (!push_tinst_level (tinst))
15656 {
15657 ggc_free (tinst);
15658 return error_mark_node;
15659 }
15660
15661 args =
15662 coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
15663 args, tmpl, complain,
15664 /*require_all_args=*/true,
15665 /*use_default_args=*/true);
15666
15667 tree r = instantiate_template (tmpl, args, complain);
15668 pop_tinst_level ();
15669 /* We can't free this if a pending_template entry or last_error_tinst_level
15670 is pointing at it. */
15671 if (last_pending_template == old_last_pend
15672 && last_error_tinst_level == old_error_tinst)
15673 ggc_free (tinst);
15674
15675 return r;
15676 }
15677
15678 /* PARM is a template parameter pack for FN. Returns true iff
15679 PARM is used in a deducible way in the argument list of FN. */
15680
15681 static bool
pack_deducible_p(tree parm,tree fn)15682 pack_deducible_p (tree parm, tree fn)
15683 {
15684 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
15685 for (; t; t = TREE_CHAIN (t))
15686 {
15687 tree type = TREE_VALUE (t);
15688 tree packs;
15689 if (!PACK_EXPANSION_P (type))
15690 continue;
15691 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
15692 packs; packs = TREE_CHAIN (packs))
15693 if (template_args_equal (TREE_VALUE (packs), parm))
15694 {
15695 /* The template parameter pack is used in a function parameter
15696 pack. If this is the end of the parameter list, the
15697 template parameter pack is deducible. */
15698 if (TREE_CHAIN (t) == void_list_node)
15699 return true;
15700 else
15701 /* Otherwise, not. Well, it could be deduced from
15702 a non-pack parameter, but doing so would end up with
15703 a deduction mismatch, so don't bother. */
15704 return false;
15705 }
15706 }
15707 /* The template parameter pack isn't used in any function parameter
15708 packs, but it might be used deeper, e.g. tuple<Args...>. */
15709 return true;
15710 }
15711
15712 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
15713 NARGS elements of the arguments that are being used when calling
15714 it. TARGS is a vector into which the deduced template arguments
15715 are placed.
15716
15717 Returns either a FUNCTION_DECL for the matching specialization of FN or
15718 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
15719 true, diagnostics will be printed to explain why it failed.
15720
15721 If FN is a conversion operator, or we are trying to produce a specific
15722 specialization, RETURN_TYPE is the return type desired.
15723
15724 The EXPLICIT_TARGS are explicit template arguments provided via a
15725 template-id.
15726
15727 The parameter STRICT is one of:
15728
15729 DEDUCE_CALL:
15730 We are deducing arguments for a function call, as in
15731 [temp.deduct.call].
15732
15733 DEDUCE_CONV:
15734 We are deducing arguments for a conversion function, as in
15735 [temp.deduct.conv].
15736
15737 DEDUCE_EXACT:
15738 We are deducing arguments when doing an explicit instantiation
15739 as in [temp.explicit], when determining an explicit specialization
15740 as in [temp.expl.spec], or when taking the address of a function
15741 template, as in [temp.deduct.funcaddr]. */
15742
15743 tree
fn_type_unification(tree fn,tree explicit_targs,tree targs,const tree * args,unsigned int nargs,tree return_type,unification_kind_t strict,int flags,bool explain_p,bool decltype_p)15744 fn_type_unification (tree fn,
15745 tree explicit_targs,
15746 tree targs,
15747 const tree *args,
15748 unsigned int nargs,
15749 tree return_type,
15750 unification_kind_t strict,
15751 int flags,
15752 bool explain_p,
15753 bool decltype_p)
15754 {
15755 tree parms;
15756 tree fntype;
15757 tree decl = NULL_TREE;
15758 tsubst_flags_t complain = (explain_p ? tf_warning_or_error : tf_none);
15759 bool ok;
15760 static int deduction_depth;
15761 struct pending_template *old_last_pend = last_pending_template;
15762 struct tinst_level *old_error_tinst = last_error_tinst_level;
15763 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
15764 tree tinst;
15765 tree r = error_mark_node;
15766
15767 if (decltype_p)
15768 complain |= tf_decltype;
15769
15770 /* In C++0x, it's possible to have a function template whose type depends
15771 on itself recursively. This is most obvious with decltype, but can also
15772 occur with enumeration scope (c++/48969). So we need to catch infinite
15773 recursion and reject the substitution at deduction time; this function
15774 will return error_mark_node for any repeated substitution.
15775
15776 This also catches excessive recursion such as when f<N> depends on
15777 f<N-1> across all integers, and returns error_mark_node for all the
15778 substitutions back up to the initial one.
15779
15780 This is, of course, not reentrant. */
15781 if (excessive_deduction_depth)
15782 return error_mark_node;
15783 tinst = build_tree_list (fn, NULL_TREE);
15784 ++deduction_depth;
15785
15786 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
15787
15788 fntype = TREE_TYPE (fn);
15789 if (explicit_targs)
15790 {
15791 /* [temp.deduct]
15792
15793 The specified template arguments must match the template
15794 parameters in kind (i.e., type, nontype, template), and there
15795 must not be more arguments than there are parameters;
15796 otherwise type deduction fails.
15797
15798 Nontype arguments must match the types of the corresponding
15799 nontype template parameters, or must be convertible to the
15800 types of the corresponding nontype parameters as specified in
15801 _temp.arg.nontype_, otherwise type deduction fails.
15802
15803 All references in the function type of the function template
15804 to the corresponding template parameters are replaced by the
15805 specified template argument values. If a substitution in a
15806 template parameter or in the function type of the function
15807 template results in an invalid type, type deduction fails. */
15808 int i, len = TREE_VEC_LENGTH (tparms);
15809 location_t loc = input_location;
15810 bool incomplete = false;
15811
15812 /* Adjust any explicit template arguments before entering the
15813 substitution context. */
15814 explicit_targs
15815 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
15816 complain,
15817 /*require_all_args=*/false,
15818 /*use_default_args=*/false));
15819 if (explicit_targs == error_mark_node)
15820 goto fail;
15821
15822 /* Substitute the explicit args into the function type. This is
15823 necessary so that, for instance, explicitly declared function
15824 arguments can match null pointed constants. If we were given
15825 an incomplete set of explicit args, we must not do semantic
15826 processing during substitution as we could create partial
15827 instantiations. */
15828 for (i = 0; i < len; i++)
15829 {
15830 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15831 bool parameter_pack = false;
15832 tree targ = TREE_VEC_ELT (explicit_targs, i);
15833
15834 /* Dig out the actual parm. */
15835 if (TREE_CODE (parm) == TYPE_DECL
15836 || TREE_CODE (parm) == TEMPLATE_DECL)
15837 {
15838 parm = TREE_TYPE (parm);
15839 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
15840 }
15841 else if (TREE_CODE (parm) == PARM_DECL)
15842 {
15843 parm = DECL_INITIAL (parm);
15844 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
15845 }
15846
15847 if (!parameter_pack && targ == NULL_TREE)
15848 /* No explicit argument for this template parameter. */
15849 incomplete = true;
15850
15851 if (parameter_pack && pack_deducible_p (parm, fn))
15852 {
15853 /* Mark the argument pack as "incomplete". We could
15854 still deduce more arguments during unification.
15855 We remove this mark in type_unification_real. */
15856 if (targ)
15857 {
15858 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
15859 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
15860 = ARGUMENT_PACK_ARGS (targ);
15861 }
15862
15863 /* We have some incomplete argument packs. */
15864 incomplete = true;
15865 }
15866 }
15867
15868 TREE_VALUE (tinst) = explicit_targs;
15869 if (!push_tinst_level (tinst))
15870 {
15871 excessive_deduction_depth = true;
15872 goto fail;
15873 }
15874 processing_template_decl += incomplete;
15875 input_location = DECL_SOURCE_LOCATION (fn);
15876 /* Ignore any access checks; we'll see them again in
15877 instantiate_template and they might have the wrong
15878 access path at this point. */
15879 push_deferring_access_checks (dk_deferred);
15880 fntype = tsubst (TREE_TYPE (fn), explicit_targs,
15881 complain | tf_partial, NULL_TREE);
15882 pop_deferring_access_checks ();
15883 input_location = loc;
15884 processing_template_decl -= incomplete;
15885 pop_tinst_level ();
15886
15887 if (fntype == error_mark_node)
15888 goto fail;
15889
15890 /* Place the explicitly specified arguments in TARGS. */
15891 for (i = NUM_TMPL_ARGS (explicit_targs); i--;)
15892 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (explicit_targs, i);
15893 }
15894
15895 /* Never do unification on the 'this' parameter. */
15896 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
15897
15898 if (return_type)
15899 {
15900 tree *new_args;
15901
15902 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
15903 new_args = XALLOCAVEC (tree, nargs + 1);
15904 new_args[0] = return_type;
15905 memcpy (new_args + 1, args, nargs * sizeof (tree));
15906 args = new_args;
15907 ++nargs;
15908 }
15909
15910 /* We allow incomplete unification without an error message here
15911 because the standard doesn't seem to explicitly prohibit it. Our
15912 callers must be ready to deal with unification failures in any
15913 event. */
15914
15915 TREE_VALUE (tinst) = targs;
15916 /* If we aren't explaining yet, push tinst context so we can see where
15917 any errors (e.g. from class instantiations triggered by instantiation
15918 of default template arguments) come from. If we are explaining, this
15919 context is redundant. */
15920 if (!explain_p && !push_tinst_level (tinst))
15921 {
15922 excessive_deduction_depth = true;
15923 goto fail;
15924 }
15925
15926 /* type_unification_real will pass back any access checks from default
15927 template argument substitution. */
15928 vec<deferred_access_check, va_gc> *checks;
15929 checks = NULL;
15930
15931 ok = !type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
15932 targs, parms, args, nargs, /*subr=*/0,
15933 strict, flags, &checks, explain_p);
15934 if (!explain_p)
15935 pop_tinst_level ();
15936 if (!ok)
15937 goto fail;
15938
15939 /* Now that we have bindings for all of the template arguments,
15940 ensure that the arguments deduced for the template template
15941 parameters have compatible template parameter lists. We cannot
15942 check this property before we have deduced all template
15943 arguments, because the template parameter types of a template
15944 template parameter might depend on prior template parameters
15945 deduced after the template template parameter. The following
15946 ill-formed example illustrates this issue:
15947
15948 template<typename T, template<T> class C> void f(C<5>, T);
15949
15950 template<int N> struct X {};
15951
15952 void g() {
15953 f(X<5>(), 5l); // error: template argument deduction fails
15954 }
15955
15956 The template parameter list of 'C' depends on the template type
15957 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
15958 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
15959 time that we deduce 'C'. */
15960 if (!template_template_parm_bindings_ok_p
15961 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
15962 {
15963 unify_inconsistent_template_template_parameters (explain_p);
15964 goto fail;
15965 }
15966
15967 /* All is well so far. Now, check:
15968
15969 [temp.deduct]
15970
15971 When all template arguments have been deduced, all uses of
15972 template parameters in nondeduced contexts are replaced with
15973 the corresponding deduced argument values. If the
15974 substitution results in an invalid type, as described above,
15975 type deduction fails. */
15976 TREE_VALUE (tinst) = targs;
15977 if (!push_tinst_level (tinst))
15978 {
15979 excessive_deduction_depth = true;
15980 goto fail;
15981 }
15982
15983 /* Also collect access checks from the instantiation. */
15984 reopen_deferring_access_checks (checks);
15985
15986 decl = instantiate_template (fn, targs, complain);
15987
15988 checks = get_deferred_access_checks ();
15989 pop_deferring_access_checks ();
15990
15991 pop_tinst_level ();
15992
15993 if (decl == error_mark_node)
15994 goto fail;
15995
15996 /* Now perform any access checks encountered during substitution. */
15997 push_access_scope (decl);
15998 ok = perform_access_checks (checks, complain);
15999 pop_access_scope (decl);
16000 if (!ok)
16001 goto fail;
16002
16003 /* If we're looking for an exact match, check that what we got
16004 is indeed an exact match. It might not be if some template
16005 parameters are used in non-deduced contexts. But don't check
16006 for an exact match if we have dependent template arguments;
16007 in that case we're doing partial ordering, and we already know
16008 that we have two candidates that will provide the actual type. */
16009 if (strict == DEDUCE_EXACT && !any_dependent_template_arguments_p (targs))
16010 {
16011 tree substed = TREE_TYPE (decl);
16012 unsigned int i;
16013
16014 tree sarg
16015 = skip_artificial_parms_for (decl, TYPE_ARG_TYPES (substed));
16016 if (return_type)
16017 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
16018 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
16019 if (!same_type_p (args[i], TREE_VALUE (sarg)))
16020 {
16021 unify_type_mismatch (explain_p, args[i],
16022 TREE_VALUE (sarg));
16023 goto fail;
16024 }
16025 }
16026
16027 r = decl;
16028
16029 fail:
16030 --deduction_depth;
16031 if (excessive_deduction_depth)
16032 {
16033 if (deduction_depth == 0)
16034 /* Reset once we're all the way out. */
16035 excessive_deduction_depth = false;
16036 }
16037
16038 /* We can't free this if a pending_template entry or last_error_tinst_level
16039 is pointing at it. */
16040 if (last_pending_template == old_last_pend
16041 && last_error_tinst_level == old_error_tinst)
16042 ggc_free (tinst);
16043
16044 return r;
16045 }
16046
16047 /* Adjust types before performing type deduction, as described in
16048 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
16049 sections are symmetric. PARM is the type of a function parameter
16050 or the return type of the conversion function. ARG is the type of
16051 the argument passed to the call, or the type of the value
16052 initialized with the result of the conversion function.
16053 ARG_EXPR is the original argument expression, which may be null. */
16054
16055 static int
maybe_adjust_types_for_deduction(unification_kind_t strict,tree * parm,tree * arg,tree arg_expr)16056 maybe_adjust_types_for_deduction (unification_kind_t strict,
16057 tree* parm,
16058 tree* arg,
16059 tree arg_expr)
16060 {
16061 int result = 0;
16062
16063 switch (strict)
16064 {
16065 case DEDUCE_CALL:
16066 break;
16067
16068 case DEDUCE_CONV:
16069 {
16070 /* Swap PARM and ARG throughout the remainder of this
16071 function; the handling is precisely symmetric since PARM
16072 will initialize ARG rather than vice versa. */
16073 tree* temp = parm;
16074 parm = arg;
16075 arg = temp;
16076 break;
16077 }
16078
16079 case DEDUCE_EXACT:
16080 /* Core issue #873: Do the DR606 thing (see below) for these cases,
16081 too, but here handle it by stripping the reference from PARM
16082 rather than by adding it to ARG. */
16083 if (TREE_CODE (*parm) == REFERENCE_TYPE
16084 && TYPE_REF_IS_RVALUE (*parm)
16085 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
16086 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
16087 && TREE_CODE (*arg) == REFERENCE_TYPE
16088 && !TYPE_REF_IS_RVALUE (*arg))
16089 *parm = TREE_TYPE (*parm);
16090 /* Nothing else to do in this case. */
16091 return 0;
16092
16093 default:
16094 gcc_unreachable ();
16095 }
16096
16097 if (TREE_CODE (*parm) != REFERENCE_TYPE)
16098 {
16099 /* [temp.deduct.call]
16100
16101 If P is not a reference type:
16102
16103 --If A is an array type, the pointer type produced by the
16104 array-to-pointer standard conversion (_conv.array_) is
16105 used in place of A for type deduction; otherwise,
16106
16107 --If A is a function type, the pointer type produced by
16108 the function-to-pointer standard conversion
16109 (_conv.func_) is used in place of A for type deduction;
16110 otherwise,
16111
16112 --If A is a cv-qualified type, the top level
16113 cv-qualifiers of A's type are ignored for type
16114 deduction. */
16115 if (TREE_CODE (*arg) == ARRAY_TYPE)
16116 *arg = build_pointer_type (TREE_TYPE (*arg));
16117 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
16118 *arg = build_pointer_type (*arg);
16119 else
16120 *arg = TYPE_MAIN_VARIANT (*arg);
16121 }
16122
16123 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
16124 of the form T&&, where T is a template parameter, and the argument
16125 is an lvalue, T is deduced as A& */
16126 if (TREE_CODE (*parm) == REFERENCE_TYPE
16127 && TYPE_REF_IS_RVALUE (*parm)
16128 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
16129 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
16130 && (arg_expr ? real_lvalue_p (arg_expr)
16131 /* try_one_overload doesn't provide an arg_expr, but
16132 functions are always lvalues. */
16133 : TREE_CODE (*arg) == FUNCTION_TYPE))
16134 *arg = build_reference_type (*arg);
16135
16136 /* [temp.deduct.call]
16137
16138 If P is a cv-qualified type, the top level cv-qualifiers
16139 of P's type are ignored for type deduction. If P is a
16140 reference type, the type referred to by P is used for
16141 type deduction. */
16142 *parm = TYPE_MAIN_VARIANT (*parm);
16143 if (TREE_CODE (*parm) == REFERENCE_TYPE)
16144 {
16145 *parm = TREE_TYPE (*parm);
16146 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16147 }
16148
16149 /* DR 322. For conversion deduction, remove a reference type on parm
16150 too (which has been swapped into ARG). */
16151 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
16152 *arg = TREE_TYPE (*arg);
16153
16154 return result;
16155 }
16156
16157 /* Subroutine of unify_one_argument. PARM is a function parameter of a
16158 template which does contain any deducible template parameters; check if
16159 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
16160 unify_one_argument. */
16161
16162 static int
check_non_deducible_conversion(tree parm,tree arg,int strict,int flags,bool explain_p)16163 check_non_deducible_conversion (tree parm, tree arg, int strict,
16164 int flags, bool explain_p)
16165 {
16166 tree type;
16167
16168 if (!TYPE_P (arg))
16169 type = TREE_TYPE (arg);
16170 else
16171 type = arg;
16172
16173 if (same_type_p (parm, type))
16174 return unify_success (explain_p);
16175
16176 if (strict == DEDUCE_CONV)
16177 {
16178 if (can_convert_arg (type, parm, NULL_TREE, flags,
16179 explain_p ? tf_warning_or_error : tf_none))
16180 return unify_success (explain_p);
16181 }
16182 else if (strict != DEDUCE_EXACT)
16183 {
16184 if (can_convert_arg (parm, type,
16185 TYPE_P (arg) ? NULL_TREE : arg,
16186 flags, explain_p ? tf_warning_or_error : tf_none))
16187 return unify_success (explain_p);
16188 }
16189
16190 if (strict == DEDUCE_EXACT)
16191 return unify_type_mismatch (explain_p, parm, arg);
16192 else
16193 return unify_arg_conversion (explain_p, parm, type, arg);
16194 }
16195
16196 static bool uses_deducible_template_parms (tree type);
16197
16198 /* Returns true iff the expression EXPR is one from which a template
16199 argument can be deduced. In other words, if it's an undecorated
16200 use of a template non-type parameter. */
16201
16202 static bool
deducible_expression(tree expr)16203 deducible_expression (tree expr)
16204 {
16205 return (TREE_CODE (expr) == TEMPLATE_PARM_INDEX);
16206 }
16207
16208 /* Returns true iff the array domain DOMAIN uses a template parameter in a
16209 deducible way; that is, if it has a max value of <PARM> - 1. */
16210
16211 static bool
deducible_array_bound(tree domain)16212 deducible_array_bound (tree domain)
16213 {
16214 if (domain == NULL_TREE)
16215 return false;
16216
16217 tree max = TYPE_MAX_VALUE (domain);
16218 if (TREE_CODE (max) != MINUS_EXPR)
16219 return false;
16220
16221 return deducible_expression (TREE_OPERAND (max, 0));
16222 }
16223
16224 /* Returns true iff the template arguments ARGS use a template parameter
16225 in a deducible way. */
16226
16227 static bool
deducible_template_args(tree args)16228 deducible_template_args (tree args)
16229 {
16230 for (int i = 0; i < TREE_VEC_LENGTH (args); ++i)
16231 {
16232 bool deducible;
16233 tree elt = TREE_VEC_ELT (args, i);
16234 if (ARGUMENT_PACK_P (elt))
16235 deducible = deducible_template_args (ARGUMENT_PACK_ARGS (elt));
16236 else
16237 {
16238 if (PACK_EXPANSION_P (elt))
16239 elt = PACK_EXPANSION_PATTERN (elt);
16240 if (TREE_CODE (elt) == TEMPLATE_TEMPLATE_PARM)
16241 deducible = true;
16242 else if (TYPE_P (elt))
16243 deducible = uses_deducible_template_parms (elt);
16244 else
16245 deducible = deducible_expression (elt);
16246 }
16247 if (deducible)
16248 return true;
16249 }
16250 return false;
16251 }
16252
16253 /* Returns true iff TYPE contains any deducible references to template
16254 parameters, as per 14.8.2.5. */
16255
16256 static bool
uses_deducible_template_parms(tree type)16257 uses_deducible_template_parms (tree type)
16258 {
16259 if (PACK_EXPANSION_P (type))
16260 type = PACK_EXPANSION_PATTERN (type);
16261
16262 /* T
16263 cv-list T
16264 TT<T>
16265 TT<i>
16266 TT<> */
16267 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
16268 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
16269 return true;
16270
16271 /* T*
16272 T&
16273 T&& */
16274 if (POINTER_TYPE_P (type))
16275 return uses_deducible_template_parms (TREE_TYPE (type));
16276
16277 /* T[integer-constant ]
16278 type [i] */
16279 if (TREE_CODE (type) == ARRAY_TYPE)
16280 return (uses_deducible_template_parms (TREE_TYPE (type))
16281 || deducible_array_bound (TYPE_DOMAIN (type)));
16282
16283 /* T type ::*
16284 type T::*
16285 T T::*
16286 T (type ::*)()
16287 type (T::*)()
16288 type (type ::*)(T)
16289 type (T::*)(T)
16290 T (type ::*)(T)
16291 T (T::*)()
16292 T (T::*)(T) */
16293 if (TYPE_PTRMEM_P (type))
16294 return (uses_deducible_template_parms (TYPE_PTRMEM_CLASS_TYPE (type))
16295 || (uses_deducible_template_parms
16296 (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
16297
16298 /* template-name <T> (where template-name refers to a class template)
16299 template-name <i> (where template-name refers to a class template) */
16300 if (CLASS_TYPE_P (type)
16301 && CLASSTYPE_TEMPLATE_INFO (type)
16302 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type)))
16303 return deducible_template_args (INNERMOST_TEMPLATE_ARGS
16304 (CLASSTYPE_TI_ARGS (type)));
16305
16306 /* type (T)
16307 T()
16308 T(T) */
16309 if (TREE_CODE (type) == FUNCTION_TYPE
16310 || TREE_CODE (type) == METHOD_TYPE)
16311 {
16312 if (uses_deducible_template_parms (TREE_TYPE (type)))
16313 return true;
16314 tree parm = TYPE_ARG_TYPES (type);
16315 if (TREE_CODE (type) == METHOD_TYPE)
16316 parm = TREE_CHAIN (parm);
16317 for (; parm; parm = TREE_CHAIN (parm))
16318 if (uses_deducible_template_parms (TREE_VALUE (parm)))
16319 return true;
16320 }
16321
16322 return false;
16323 }
16324
16325 /* Subroutine of type_unification_real and unify_pack_expansion to
16326 handle unification of a single P/A pair. Parameters are as
16327 for those functions. */
16328
16329 static int
unify_one_argument(tree tparms,tree targs,tree parm,tree arg,int subr,unification_kind_t strict,int flags,bool explain_p)16330 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
16331 int subr, unification_kind_t strict, int flags,
16332 bool explain_p)
16333 {
16334 tree arg_expr = NULL_TREE;
16335 int arg_strict;
16336
16337 if (arg == error_mark_node || parm == error_mark_node)
16338 return unify_invalid (explain_p);
16339 if (arg == unknown_type_node)
16340 /* We can't deduce anything from this, but we might get all the
16341 template args from other function args. */
16342 return unify_success (explain_p);
16343
16344 /* Implicit conversions (Clause 4) will be performed on a function
16345 argument to convert it to the type of the corresponding function
16346 parameter if the parameter type contains no template-parameters that
16347 participate in template argument deduction. */
16348 if (TYPE_P (parm) && !uses_template_parms (parm))
16349 /* For function parameters that contain no template-parameters at all,
16350 we have historically checked for convertibility in order to shortcut
16351 consideration of this candidate. */
16352 return check_non_deducible_conversion (parm, arg, strict, flags,
16353 explain_p);
16354 else if (strict == DEDUCE_CALL
16355 && TYPE_P (parm) && !uses_deducible_template_parms (parm))
16356 /* For function parameters with only non-deducible template parameters,
16357 just return. */
16358 return unify_success (explain_p);
16359
16360 switch (strict)
16361 {
16362 case DEDUCE_CALL:
16363 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
16364 | UNIFY_ALLOW_MORE_CV_QUAL
16365 | UNIFY_ALLOW_DERIVED);
16366 break;
16367
16368 case DEDUCE_CONV:
16369 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
16370 break;
16371
16372 case DEDUCE_EXACT:
16373 arg_strict = UNIFY_ALLOW_NONE;
16374 break;
16375
16376 default:
16377 gcc_unreachable ();
16378 }
16379
16380 /* We only do these transformations if this is the top-level
16381 parameter_type_list in a call or declaration matching; in other
16382 situations (nested function declarators, template argument lists) we
16383 won't be comparing a type to an expression, and we don't do any type
16384 adjustments. */
16385 if (!subr)
16386 {
16387 if (!TYPE_P (arg))
16388 {
16389 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
16390 if (type_unknown_p (arg))
16391 {
16392 /* [temp.deduct.type] A template-argument can be
16393 deduced from a pointer to function or pointer
16394 to member function argument if the set of
16395 overloaded functions does not contain function
16396 templates and at most one of a set of
16397 overloaded functions provides a unique
16398 match. */
16399
16400 if (resolve_overloaded_unification
16401 (tparms, targs, parm, arg, strict,
16402 arg_strict, explain_p))
16403 return unify_success (explain_p);
16404 return unify_overload_resolution_failure (explain_p, arg);
16405 }
16406
16407 arg_expr = arg;
16408 arg = unlowered_expr_type (arg);
16409 if (arg == error_mark_node)
16410 return unify_invalid (explain_p);
16411 }
16412
16413 arg_strict |=
16414 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
16415 }
16416 else
16417 if ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
16418 != (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL))
16419 return unify_template_argument_mismatch (explain_p, parm, arg);
16420
16421 /* For deduction from an init-list we need the actual list. */
16422 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
16423 arg = arg_expr;
16424 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
16425 }
16426
16427 /* Most parms like fn_type_unification.
16428
16429 If SUBR is 1, we're being called recursively (to unify the
16430 arguments of a function or method parameter of a function
16431 template).
16432
16433 CHECKS is a pointer to a vector of access checks encountered while
16434 substituting default template arguments. */
16435
16436 static int
type_unification_real(tree tparms,tree targs,tree xparms,const tree * xargs,unsigned int xnargs,int subr,unification_kind_t strict,int flags,vec<deferred_access_check,va_gc> ** checks,bool explain_p)16437 type_unification_real (tree tparms,
16438 tree targs,
16439 tree xparms,
16440 const tree *xargs,
16441 unsigned int xnargs,
16442 int subr,
16443 unification_kind_t strict,
16444 int flags,
16445 vec<deferred_access_check, va_gc> **checks,
16446 bool explain_p)
16447 {
16448 tree parm, arg;
16449 int i;
16450 int ntparms = TREE_VEC_LENGTH (tparms);
16451 int saw_undeduced = 0;
16452 tree parms;
16453 const tree *args;
16454 unsigned int nargs;
16455 unsigned int ia;
16456
16457 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
16458 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
16459 gcc_assert (ntparms > 0);
16460
16461 /* Reset the number of non-defaulted template arguments contained
16462 in TARGS. */
16463 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
16464
16465 again:
16466 parms = xparms;
16467 args = xargs;
16468 nargs = xnargs;
16469
16470 ia = 0;
16471 while (parms && parms != void_list_node
16472 && ia < nargs)
16473 {
16474 parm = TREE_VALUE (parms);
16475
16476 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
16477 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
16478 /* For a function parameter pack that occurs at the end of the
16479 parameter-declaration-list, the type A of each remaining
16480 argument of the call is compared with the type P of the
16481 declarator-id of the function parameter pack. */
16482 break;
16483
16484 parms = TREE_CHAIN (parms);
16485
16486 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
16487 /* For a function parameter pack that does not occur at the
16488 end of the parameter-declaration-list, the type of the
16489 parameter pack is a non-deduced context. */
16490 continue;
16491
16492 arg = args[ia];
16493 ++ia;
16494
16495 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
16496 flags, explain_p))
16497 return 1;
16498 }
16499
16500 if (parms
16501 && parms != void_list_node
16502 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
16503 {
16504 /* Unify the remaining arguments with the pack expansion type. */
16505 tree argvec;
16506 tree parmvec = make_tree_vec (1);
16507
16508 /* Allocate a TREE_VEC and copy in all of the arguments */
16509 argvec = make_tree_vec (nargs - ia);
16510 for (i = 0; ia < nargs; ++ia, ++i)
16511 TREE_VEC_ELT (argvec, i) = args[ia];
16512
16513 /* Copy the parameter into parmvec. */
16514 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
16515 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
16516 /*subr=*/subr, explain_p))
16517 return 1;
16518
16519 /* Advance to the end of the list of parameters. */
16520 parms = TREE_CHAIN (parms);
16521 }
16522
16523 /* Fail if we've reached the end of the parm list, and more args
16524 are present, and the parm list isn't variadic. */
16525 if (ia < nargs && parms == void_list_node)
16526 return unify_too_many_arguments (explain_p, nargs, ia);
16527 /* Fail if parms are left and they don't have default values. */
16528 if (parms && parms != void_list_node
16529 && TREE_PURPOSE (parms) == NULL_TREE)
16530 {
16531 unsigned int count = nargs;
16532 tree p = parms;
16533 while (p && p != void_list_node)
16534 {
16535 count++;
16536 p = TREE_CHAIN (p);
16537 }
16538 return unify_too_few_arguments (explain_p, ia, count);
16539 }
16540
16541 if (!subr)
16542 {
16543 tsubst_flags_t complain = (explain_p
16544 ? tf_warning_or_error
16545 : tf_none);
16546
16547 for (i = 0; i < ntparms; i++)
16548 {
16549 tree targ = TREE_VEC_ELT (targs, i);
16550 tree tparm = TREE_VEC_ELT (tparms, i);
16551
16552 /* Clear the "incomplete" flags on all argument packs now so that
16553 substituting them into later default arguments works. */
16554 if (targ && ARGUMENT_PACK_P (targ))
16555 {
16556 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
16557 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
16558 }
16559
16560 if (targ || tparm == error_mark_node)
16561 continue;
16562 tparm = TREE_VALUE (tparm);
16563
16564 /* If this is an undeduced nontype parameter that depends on
16565 a type parameter, try another pass; its type may have been
16566 deduced from a later argument than the one from which
16567 this parameter can be deduced. */
16568 if (TREE_CODE (tparm) == PARM_DECL
16569 && uses_template_parms (TREE_TYPE (tparm))
16570 && !saw_undeduced++)
16571 goto again;
16572
16573 /* Core issue #226 (C++0x) [temp.deduct]:
16574
16575 If a template argument has not been deduced, its
16576 default template argument, if any, is used.
16577
16578 When we are in C++98 mode, TREE_PURPOSE will either
16579 be NULL_TREE or ERROR_MARK_NODE, so we do not need
16580 to explicitly check cxx_dialect here. */
16581 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
16582 {
16583 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
16584 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
16585 reopen_deferring_access_checks (*checks);
16586 location_t save_loc = input_location;
16587 if (DECL_P (parm))
16588 input_location = DECL_SOURCE_LOCATION (parm);
16589 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
16590 arg = convert_template_argument (parm, arg, targs, complain,
16591 i, NULL_TREE);
16592 input_location = save_loc;
16593 *checks = get_deferred_access_checks ();
16594 pop_deferring_access_checks ();
16595 if (arg == error_mark_node)
16596 return 1;
16597 else
16598 {
16599 TREE_VEC_ELT (targs, i) = arg;
16600 /* The position of the first default template argument,
16601 is also the number of non-defaulted arguments in TARGS.
16602 Record that. */
16603 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
16604 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
16605 continue;
16606 }
16607 }
16608
16609 /* If the type parameter is a parameter pack, then it will
16610 be deduced to an empty parameter pack. */
16611 if (template_parameter_pack_p (tparm))
16612 {
16613 tree arg;
16614
16615 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
16616 {
16617 arg = make_node (NONTYPE_ARGUMENT_PACK);
16618 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
16619 TREE_CONSTANT (arg) = 1;
16620 }
16621 else
16622 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
16623
16624 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
16625
16626 TREE_VEC_ELT (targs, i) = arg;
16627 continue;
16628 }
16629
16630 return unify_parameter_deduction_failure (explain_p, tparm);
16631 }
16632 }
16633 #ifdef ENABLE_CHECKING
16634 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
16635 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
16636 #endif
16637
16638 return unify_success (explain_p);
16639 }
16640
16641 /* Subroutine of type_unification_real. Args are like the variables
16642 at the call site. ARG is an overloaded function (or template-id);
16643 we try deducing template args from each of the overloads, and if
16644 only one succeeds, we go with that. Modifies TARGS and returns
16645 true on success. */
16646
16647 static bool
resolve_overloaded_unification(tree tparms,tree targs,tree parm,tree arg,unification_kind_t strict,int sub_strict,bool explain_p)16648 resolve_overloaded_unification (tree tparms,
16649 tree targs,
16650 tree parm,
16651 tree arg,
16652 unification_kind_t strict,
16653 int sub_strict,
16654 bool explain_p)
16655 {
16656 tree tempargs = copy_node (targs);
16657 int good = 0;
16658 tree goodfn = NULL_TREE;
16659 bool addr_p;
16660
16661 if (TREE_CODE (arg) == ADDR_EXPR)
16662 {
16663 arg = TREE_OPERAND (arg, 0);
16664 addr_p = true;
16665 }
16666 else
16667 addr_p = false;
16668
16669 if (TREE_CODE (arg) == COMPONENT_REF)
16670 /* Handle `&x' where `x' is some static or non-static member
16671 function name. */
16672 arg = TREE_OPERAND (arg, 1);
16673
16674 if (TREE_CODE (arg) == OFFSET_REF)
16675 arg = TREE_OPERAND (arg, 1);
16676
16677 /* Strip baselink information. */
16678 if (BASELINK_P (arg))
16679 arg = BASELINK_FUNCTIONS (arg);
16680
16681 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
16682 {
16683 /* If we got some explicit template args, we need to plug them into
16684 the affected templates before we try to unify, in case the
16685 explicit args will completely resolve the templates in question. */
16686
16687 int ok = 0;
16688 tree expl_subargs = TREE_OPERAND (arg, 1);
16689 arg = TREE_OPERAND (arg, 0);
16690
16691 for (; arg; arg = OVL_NEXT (arg))
16692 {
16693 tree fn = OVL_CURRENT (arg);
16694 tree subargs, elem;
16695
16696 if (TREE_CODE (fn) != TEMPLATE_DECL)
16697 continue;
16698
16699 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
16700 expl_subargs, NULL_TREE, tf_none,
16701 /*require_all_args=*/true,
16702 /*use_default_args=*/true);
16703 if (subargs != error_mark_node
16704 && !any_dependent_template_arguments_p (subargs))
16705 {
16706 elem = TREE_TYPE (instantiate_template (fn, subargs, tf_none));
16707 if (try_one_overload (tparms, targs, tempargs, parm,
16708 elem, strict, sub_strict, addr_p, explain_p)
16709 && (!goodfn || !same_type_p (goodfn, elem)))
16710 {
16711 goodfn = elem;
16712 ++good;
16713 }
16714 }
16715 else if (subargs)
16716 ++ok;
16717 }
16718 /* If no templates (or more than one) are fully resolved by the
16719 explicit arguments, this template-id is a non-deduced context; it
16720 could still be OK if we deduce all template arguments for the
16721 enclosing call through other arguments. */
16722 if (good != 1)
16723 good = ok;
16724 }
16725 else if (TREE_CODE (arg) != OVERLOAD
16726 && TREE_CODE (arg) != FUNCTION_DECL)
16727 /* If ARG is, for example, "(0, &f)" then its type will be unknown
16728 -- but the deduction does not succeed because the expression is
16729 not just the function on its own. */
16730 return false;
16731 else
16732 for (; arg; arg = OVL_NEXT (arg))
16733 if (try_one_overload (tparms, targs, tempargs, parm,
16734 TREE_TYPE (OVL_CURRENT (arg)),
16735 strict, sub_strict, addr_p, explain_p)
16736 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
16737 {
16738 goodfn = OVL_CURRENT (arg);
16739 ++good;
16740 }
16741
16742 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16743 to function or pointer to member function argument if the set of
16744 overloaded functions does not contain function templates and at most
16745 one of a set of overloaded functions provides a unique match.
16746
16747 So if we found multiple possibilities, we return success but don't
16748 deduce anything. */
16749
16750 if (good == 1)
16751 {
16752 int i = TREE_VEC_LENGTH (targs);
16753 for (; i--; )
16754 if (TREE_VEC_ELT (tempargs, i))
16755 {
16756 tree old = TREE_VEC_ELT (targs, i);
16757 tree new_ = TREE_VEC_ELT (tempargs, i);
16758 if (new_ && old && ARGUMENT_PACK_P (old)
16759 && ARGUMENT_PACK_EXPLICIT_ARGS (old))
16760 /* Don't forget explicit template arguments in a pack. */
16761 ARGUMENT_PACK_EXPLICIT_ARGS (new_)
16762 = ARGUMENT_PACK_EXPLICIT_ARGS (old);
16763 TREE_VEC_ELT (targs, i) = new_;
16764 }
16765 }
16766 if (good)
16767 return true;
16768
16769 return false;
16770 }
16771
16772 /* Core DR 115: In contexts where deduction is done and fails, or in
16773 contexts where deduction is not done, if a template argument list is
16774 specified and it, along with any default template arguments, identifies
16775 a single function template specialization, then the template-id is an
16776 lvalue for the function template specialization. */
16777
16778 tree
resolve_nondeduced_context(tree orig_expr)16779 resolve_nondeduced_context (tree orig_expr)
16780 {
16781 tree expr, offset, baselink;
16782 bool addr;
16783
16784 if (!type_unknown_p (orig_expr))
16785 return orig_expr;
16786
16787 expr = orig_expr;
16788 addr = false;
16789 offset = NULL_TREE;
16790 baselink = NULL_TREE;
16791
16792 if (TREE_CODE (expr) == ADDR_EXPR)
16793 {
16794 expr = TREE_OPERAND (expr, 0);
16795 addr = true;
16796 }
16797 if (TREE_CODE (expr) == OFFSET_REF)
16798 {
16799 offset = expr;
16800 expr = TREE_OPERAND (expr, 1);
16801 }
16802 if (BASELINK_P (expr))
16803 {
16804 baselink = expr;
16805 expr = BASELINK_FUNCTIONS (expr);
16806 }
16807
16808 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
16809 {
16810 int good = 0;
16811 tree goodfn = NULL_TREE;
16812
16813 /* If we got some explicit template args, we need to plug them into
16814 the affected templates before we try to unify, in case the
16815 explicit args will completely resolve the templates in question. */
16816
16817 tree expl_subargs = TREE_OPERAND (expr, 1);
16818 tree arg = TREE_OPERAND (expr, 0);
16819 tree badfn = NULL_TREE;
16820 tree badargs = NULL_TREE;
16821
16822 for (; arg; arg = OVL_NEXT (arg))
16823 {
16824 tree fn = OVL_CURRENT (arg);
16825 tree subargs, elem;
16826
16827 if (TREE_CODE (fn) != TEMPLATE_DECL)
16828 continue;
16829
16830 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
16831 expl_subargs, NULL_TREE, tf_none,
16832 /*require_all_args=*/true,
16833 /*use_default_args=*/true);
16834 if (subargs != error_mark_node
16835 && !any_dependent_template_arguments_p (subargs))
16836 {
16837 elem = instantiate_template (fn, subargs, tf_none);
16838 if (elem == error_mark_node)
16839 {
16840 badfn = fn;
16841 badargs = subargs;
16842 }
16843 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
16844 {
16845 goodfn = elem;
16846 ++good;
16847 }
16848 }
16849 }
16850 if (good == 1)
16851 {
16852 mark_used (goodfn);
16853 expr = goodfn;
16854 if (baselink)
16855 expr = build_baselink (BASELINK_BINFO (baselink),
16856 BASELINK_ACCESS_BINFO (baselink),
16857 expr, BASELINK_OPTYPE (baselink));
16858 if (offset)
16859 {
16860 tree base
16861 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
16862 expr = build_offset_ref (base, expr, addr, tf_warning_or_error);
16863 }
16864 if (addr)
16865 expr = cp_build_addr_expr (expr, tf_warning_or_error);
16866 return expr;
16867 }
16868 else if (good == 0 && badargs)
16869 /* There were no good options and at least one bad one, so let the
16870 user know what the problem is. */
16871 instantiate_template (badfn, badargs, tf_warning_or_error);
16872 }
16873 return orig_expr;
16874 }
16875
16876 /* Subroutine of resolve_overloaded_unification; does deduction for a single
16877 overload. Fills TARGS with any deduced arguments, or error_mark_node if
16878 different overloads deduce different arguments for a given parm.
16879 ADDR_P is true if the expression for which deduction is being
16880 performed was of the form "& fn" rather than simply "fn".
16881
16882 Returns 1 on success. */
16883
16884 static int
try_one_overload(tree tparms,tree orig_targs,tree targs,tree parm,tree arg,unification_kind_t strict,int sub_strict,bool addr_p,bool explain_p)16885 try_one_overload (tree tparms,
16886 tree orig_targs,
16887 tree targs,
16888 tree parm,
16889 tree arg,
16890 unification_kind_t strict,
16891 int sub_strict,
16892 bool addr_p,
16893 bool explain_p)
16894 {
16895 int nargs;
16896 tree tempargs;
16897 int i;
16898
16899 if (arg == error_mark_node)
16900 return 0;
16901
16902 /* [temp.deduct.type] A template-argument can be deduced from a pointer
16903 to function or pointer to member function argument if the set of
16904 overloaded functions does not contain function templates and at most
16905 one of a set of overloaded functions provides a unique match.
16906
16907 So if this is a template, just return success. */
16908
16909 if (uses_template_parms (arg))
16910 return 1;
16911
16912 if (TREE_CODE (arg) == METHOD_TYPE)
16913 arg = build_ptrmemfunc_type (build_pointer_type (arg));
16914 else if (addr_p)
16915 arg = build_pointer_type (arg);
16916
16917 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
16918
16919 /* We don't copy orig_targs for this because if we have already deduced
16920 some template args from previous args, unify would complain when we
16921 try to deduce a template parameter for the same argument, even though
16922 there isn't really a conflict. */
16923 nargs = TREE_VEC_LENGTH (targs);
16924 tempargs = make_tree_vec (nargs);
16925
16926 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
16927 return 0;
16928
16929 /* First make sure we didn't deduce anything that conflicts with
16930 explicitly specified args. */
16931 for (i = nargs; i--; )
16932 {
16933 tree elt = TREE_VEC_ELT (tempargs, i);
16934 tree oldelt = TREE_VEC_ELT (orig_targs, i);
16935
16936 if (!elt)
16937 /*NOP*/;
16938 else if (uses_template_parms (elt))
16939 /* Since we're unifying against ourselves, we will fill in
16940 template args used in the function parm list with our own
16941 template parms. Discard them. */
16942 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
16943 else if (oldelt && !template_args_equal (oldelt, elt))
16944 return 0;
16945 }
16946
16947 for (i = nargs; i--; )
16948 {
16949 tree elt = TREE_VEC_ELT (tempargs, i);
16950
16951 if (elt)
16952 TREE_VEC_ELT (targs, i) = elt;
16953 }
16954
16955 return 1;
16956 }
16957
16958 /* PARM is a template class (perhaps with unbound template
16959 parameters). ARG is a fully instantiated type. If ARG can be
16960 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
16961 TARGS are as for unify. */
16962
16963 static tree
try_class_unification(tree tparms,tree targs,tree parm,tree arg,bool explain_p)16964 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
16965 bool explain_p)
16966 {
16967 tree copy_of_targs;
16968
16969 if (!CLASSTYPE_TEMPLATE_INFO (arg)
16970 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
16971 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
16972 return NULL_TREE;
16973
16974 /* We need to make a new template argument vector for the call to
16975 unify. If we used TARGS, we'd clutter it up with the result of
16976 the attempted unification, even if this class didn't work out.
16977 We also don't want to commit ourselves to all the unifications
16978 we've already done, since unification is supposed to be done on
16979 an argument-by-argument basis. In other words, consider the
16980 following pathological case:
16981
16982 template <int I, int J, int K>
16983 struct S {};
16984
16985 template <int I, int J>
16986 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
16987
16988 template <int I, int J, int K>
16989 void f(S<I, J, K>, S<I, I, I>);
16990
16991 void g() {
16992 S<0, 0, 0> s0;
16993 S<0, 1, 2> s2;
16994
16995 f(s0, s2);
16996 }
16997
16998 Now, by the time we consider the unification involving `s2', we
16999 already know that we must have `f<0, 0, 0>'. But, even though
17000 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
17001 because there are two ways to unify base classes of S<0, 1, 2>
17002 with S<I, I, I>. If we kept the already deduced knowledge, we
17003 would reject the possibility I=1. */
17004 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
17005
17006 /* If unification failed, we're done. */
17007 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
17008 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
17009 return NULL_TREE;
17010
17011 return arg;
17012 }
17013
17014 /* Given a template type PARM and a class type ARG, find the unique
17015 base type in ARG that is an instance of PARM. We do not examine
17016 ARG itself; only its base-classes. If there is not exactly one
17017 appropriate base class, return NULL_TREE. PARM may be the type of
17018 a partial specialization, as well as a plain template type. Used
17019 by unify. */
17020
17021 static enum template_base_result
get_template_base(tree tparms,tree targs,tree parm,tree arg,bool explain_p,tree * result)17022 get_template_base (tree tparms, tree targs, tree parm, tree arg,
17023 bool explain_p, tree *result)
17024 {
17025 tree rval = NULL_TREE;
17026 tree binfo;
17027
17028 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
17029
17030 binfo = TYPE_BINFO (complete_type (arg));
17031 if (!binfo)
17032 {
17033 /* The type could not be completed. */
17034 *result = NULL_TREE;
17035 return tbr_incomplete_type;
17036 }
17037
17038 /* Walk in inheritance graph order. The search order is not
17039 important, and this avoids multiple walks of virtual bases. */
17040 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
17041 {
17042 tree r = try_class_unification (tparms, targs, parm,
17043 BINFO_TYPE (binfo), explain_p);
17044
17045 if (r)
17046 {
17047 /* If there is more than one satisfactory baseclass, then:
17048
17049 [temp.deduct.call]
17050
17051 If they yield more than one possible deduced A, the type
17052 deduction fails.
17053
17054 applies. */
17055 if (rval && !same_type_p (r, rval))
17056 {
17057 *result = NULL_TREE;
17058 return tbr_ambiguous_baseclass;
17059 }
17060
17061 rval = r;
17062 }
17063 }
17064
17065 *result = rval;
17066 return tbr_success;
17067 }
17068
17069 /* Returns the level of DECL, which declares a template parameter. */
17070
17071 static int
template_decl_level(tree decl)17072 template_decl_level (tree decl)
17073 {
17074 switch (TREE_CODE (decl))
17075 {
17076 case TYPE_DECL:
17077 case TEMPLATE_DECL:
17078 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
17079
17080 case PARM_DECL:
17081 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
17082
17083 default:
17084 gcc_unreachable ();
17085 }
17086 return 0;
17087 }
17088
17089 /* Decide whether ARG can be unified with PARM, considering only the
17090 cv-qualifiers of each type, given STRICT as documented for unify.
17091 Returns nonzero iff the unification is OK on that basis. */
17092
17093 static int
check_cv_quals_for_unify(int strict,tree arg,tree parm)17094 check_cv_quals_for_unify (int strict, tree arg, tree parm)
17095 {
17096 int arg_quals = cp_type_quals (arg);
17097 int parm_quals = cp_type_quals (parm);
17098
17099 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
17100 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
17101 {
17102 /* Although a CVR qualifier is ignored when being applied to a
17103 substituted template parameter ([8.3.2]/1 for example), that
17104 does not allow us to unify "const T" with "int&" because both
17105 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
17106 It is ok when we're allowing additional CV qualifiers
17107 at the outer level [14.8.2.1]/3,1st bullet. */
17108 if ((TREE_CODE (arg) == REFERENCE_TYPE
17109 || TREE_CODE (arg) == FUNCTION_TYPE
17110 || TREE_CODE (arg) == METHOD_TYPE)
17111 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
17112 return 0;
17113
17114 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
17115 && (parm_quals & TYPE_QUAL_RESTRICT))
17116 return 0;
17117 }
17118
17119 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
17120 && (arg_quals & parm_quals) != parm_quals)
17121 return 0;
17122
17123 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
17124 && (parm_quals & arg_quals) != arg_quals)
17125 return 0;
17126
17127 return 1;
17128 }
17129
17130 /* Determines the LEVEL and INDEX for the template parameter PARM. */
17131 void
template_parm_level_and_index(tree parm,int * level,int * index)17132 template_parm_level_and_index (tree parm, int* level, int* index)
17133 {
17134 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
17135 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
17136 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
17137 {
17138 *index = TEMPLATE_TYPE_IDX (parm);
17139 *level = TEMPLATE_TYPE_LEVEL (parm);
17140 }
17141 else
17142 {
17143 *index = TEMPLATE_PARM_IDX (parm);
17144 *level = TEMPLATE_PARM_LEVEL (parm);
17145 }
17146 }
17147
17148 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
17149 do { \
17150 if (unify (TP, TA, P, A, S, EP)) \
17151 return 1; \
17152 } while (0);
17153
17154 /* Unifies the remaining arguments in PACKED_ARGS with the pack
17155 expansion at the end of PACKED_PARMS. Returns 0 if the type
17156 deduction succeeds, 1 otherwise. STRICT is the same as in
17157 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
17158 call argument list. We'll need to adjust the arguments to make them
17159 types. SUBR tells us if this is from a recursive call to
17160 type_unification_real, or for comparing two template argument
17161 lists. */
17162
17163 static int
unify_pack_expansion(tree tparms,tree targs,tree packed_parms,tree packed_args,unification_kind_t strict,bool subr,bool explain_p)17164 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
17165 tree packed_args, unification_kind_t strict,
17166 bool subr, bool explain_p)
17167 {
17168 tree parm
17169 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
17170 tree pattern = PACK_EXPANSION_PATTERN (parm);
17171 tree pack, packs = NULL_TREE;
17172 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
17173
17174 packed_args = expand_template_argument_pack (packed_args);
17175
17176 int len = TREE_VEC_LENGTH (packed_args);
17177
17178 /* Determine the parameter packs we will be deducing from the
17179 pattern, and record their current deductions. */
17180 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
17181 pack; pack = TREE_CHAIN (pack))
17182 {
17183 tree parm_pack = TREE_VALUE (pack);
17184 int idx, level;
17185
17186 /* Determine the index and level of this parameter pack. */
17187 template_parm_level_and_index (parm_pack, &level, &idx);
17188
17189 /* Keep track of the parameter packs and their corresponding
17190 argument packs. */
17191 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
17192 TREE_TYPE (packs) = make_tree_vec (len - start);
17193 }
17194
17195 /* Loop through all of the arguments that have not yet been
17196 unified and unify each with the pattern. */
17197 for (i = start; i < len; i++)
17198 {
17199 tree parm;
17200 bool any_explicit = false;
17201 tree arg = TREE_VEC_ELT (packed_args, i);
17202
17203 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
17204 or the element of its argument pack at the current index if
17205 this argument was explicitly specified. */
17206 for (pack = packs; pack; pack = TREE_CHAIN (pack))
17207 {
17208 int idx, level;
17209 tree arg, pargs;
17210 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
17211
17212 arg = NULL_TREE;
17213 if (TREE_VALUE (pack)
17214 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
17215 && (i - start < TREE_VEC_LENGTH (pargs)))
17216 {
17217 any_explicit = true;
17218 arg = TREE_VEC_ELT (pargs, i - start);
17219 }
17220 TMPL_ARG (targs, level, idx) = arg;
17221 }
17222
17223 /* If we had explicit template arguments, substitute them into the
17224 pattern before deduction. */
17225 if (any_explicit)
17226 {
17227 /* Some arguments might still be unspecified or dependent. */
17228 bool dependent;
17229 ++processing_template_decl;
17230 dependent = any_dependent_template_arguments_p (targs);
17231 if (!dependent)
17232 --processing_template_decl;
17233 parm = tsubst (pattern, targs,
17234 explain_p ? tf_warning_or_error : tf_none,
17235 NULL_TREE);
17236 if (dependent)
17237 --processing_template_decl;
17238 if (parm == error_mark_node)
17239 return 1;
17240 }
17241 else
17242 parm = pattern;
17243
17244 /* Unify the pattern with the current argument. */
17245 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
17246 LOOKUP_IMPLICIT, explain_p))
17247 return 1;
17248
17249 /* For each parameter pack, collect the deduced value. */
17250 for (pack = packs; pack; pack = TREE_CHAIN (pack))
17251 {
17252 int idx, level;
17253 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
17254
17255 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
17256 TMPL_ARG (targs, level, idx);
17257 }
17258 }
17259
17260 /* Verify that the results of unification with the parameter packs
17261 produce results consistent with what we've seen before, and make
17262 the deduced argument packs available. */
17263 for (pack = packs; pack; pack = TREE_CHAIN (pack))
17264 {
17265 tree old_pack = TREE_VALUE (pack);
17266 tree new_args = TREE_TYPE (pack);
17267 int i, len = TREE_VEC_LENGTH (new_args);
17268 int idx, level;
17269 bool nondeduced_p = false;
17270
17271 /* By default keep the original deduced argument pack.
17272 If necessary, more specific code is going to update the
17273 resulting deduced argument later down in this function. */
17274 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
17275 TMPL_ARG (targs, level, idx) = old_pack;
17276
17277 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
17278 actually deduce anything. */
17279 for (i = 0; i < len && !nondeduced_p; ++i)
17280 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
17281 nondeduced_p = true;
17282 if (nondeduced_p)
17283 continue;
17284
17285 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
17286 {
17287 /* If we had fewer function args than explicit template args,
17288 just use the explicits. */
17289 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
17290 int explicit_len = TREE_VEC_LENGTH (explicit_args);
17291 if (len < explicit_len)
17292 new_args = explicit_args;
17293 }
17294
17295 if (!old_pack)
17296 {
17297 tree result;
17298 /* Build the deduced *_ARGUMENT_PACK. */
17299 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
17300 {
17301 result = make_node (NONTYPE_ARGUMENT_PACK);
17302 TREE_TYPE (result) =
17303 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
17304 TREE_CONSTANT (result) = 1;
17305 }
17306 else
17307 result = cxx_make_type (TYPE_ARGUMENT_PACK);
17308
17309 SET_ARGUMENT_PACK_ARGS (result, new_args);
17310
17311 /* Note the deduced argument packs for this parameter
17312 pack. */
17313 TMPL_ARG (targs, level, idx) = result;
17314 }
17315 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
17316 && (ARGUMENT_PACK_ARGS (old_pack)
17317 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
17318 {
17319 /* We only had the explicitly-provided arguments before, but
17320 now we have a complete set of arguments. */
17321 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
17322
17323 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
17324 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
17325 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
17326 }
17327 else
17328 {
17329 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
17330 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
17331
17332 if (!comp_template_args_with_info (old_args, new_args,
17333 &bad_old_arg, &bad_new_arg))
17334 /* Inconsistent unification of this parameter pack. */
17335 return unify_parameter_pack_inconsistent (explain_p,
17336 bad_old_arg,
17337 bad_new_arg);
17338 }
17339 }
17340
17341 return unify_success (explain_p);
17342 }
17343
17344 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
17345 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
17346 parameters and return value are as for unify. */
17347
17348 static int
unify_array_domain(tree tparms,tree targs,tree parm_dom,tree arg_dom,bool explain_p)17349 unify_array_domain (tree tparms, tree targs,
17350 tree parm_dom, tree arg_dom,
17351 bool explain_p)
17352 {
17353 tree parm_max;
17354 tree arg_max;
17355 bool parm_cst;
17356 bool arg_cst;
17357
17358 /* Our representation of array types uses "N - 1" as the
17359 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
17360 not an integer constant. We cannot unify arbitrarily
17361 complex expressions, so we eliminate the MINUS_EXPRs
17362 here. */
17363 parm_max = TYPE_MAX_VALUE (parm_dom);
17364 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
17365 if (!parm_cst)
17366 {
17367 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
17368 parm_max = TREE_OPERAND (parm_max, 0);
17369 }
17370 arg_max = TYPE_MAX_VALUE (arg_dom);
17371 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
17372 if (!arg_cst)
17373 {
17374 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
17375 trying to unify the type of a variable with the type
17376 of a template parameter. For example:
17377
17378 template <unsigned int N>
17379 void f (char (&) [N]);
17380 int g();
17381 void h(int i) {
17382 char a[g(i)];
17383 f(a);
17384 }
17385
17386 Here, the type of the ARG will be "int [g(i)]", and
17387 may be a SAVE_EXPR, etc. */
17388 if (TREE_CODE (arg_max) != MINUS_EXPR)
17389 return unify_vla_arg (explain_p, arg_dom);
17390 arg_max = TREE_OPERAND (arg_max, 0);
17391 }
17392
17393 /* If only one of the bounds used a MINUS_EXPR, compensate
17394 by adding one to the other bound. */
17395 if (parm_cst && !arg_cst)
17396 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
17397 integer_type_node,
17398 parm_max,
17399 integer_one_node);
17400 else if (arg_cst && !parm_cst)
17401 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
17402 integer_type_node,
17403 arg_max,
17404 integer_one_node);
17405
17406 return unify (tparms, targs, parm_max, arg_max,
17407 UNIFY_ALLOW_INTEGER, explain_p);
17408 }
17409
17410 /* Deduce the value of template parameters. TPARMS is the (innermost)
17411 set of template parameters to a template. TARGS is the bindings
17412 for those template parameters, as determined thus far; TARGS may
17413 include template arguments for outer levels of template parameters
17414 as well. PARM is a parameter to a template function, or a
17415 subcomponent of that parameter; ARG is the corresponding argument.
17416 This function attempts to match PARM with ARG in a manner
17417 consistent with the existing assignments in TARGS. If more values
17418 are deduced, then TARGS is updated.
17419
17420 Returns 0 if the type deduction succeeds, 1 otherwise. The
17421 parameter STRICT is a bitwise or of the following flags:
17422
17423 UNIFY_ALLOW_NONE:
17424 Require an exact match between PARM and ARG.
17425 UNIFY_ALLOW_MORE_CV_QUAL:
17426 Allow the deduced ARG to be more cv-qualified (by qualification
17427 conversion) than ARG.
17428 UNIFY_ALLOW_LESS_CV_QUAL:
17429 Allow the deduced ARG to be less cv-qualified than ARG.
17430 UNIFY_ALLOW_DERIVED:
17431 Allow the deduced ARG to be a template base class of ARG,
17432 or a pointer to a template base class of the type pointed to by
17433 ARG.
17434 UNIFY_ALLOW_INTEGER:
17435 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
17436 case for more information.
17437 UNIFY_ALLOW_OUTER_LEVEL:
17438 This is the outermost level of a deduction. Used to determine validity
17439 of qualification conversions. A valid qualification conversion must
17440 have const qualified pointers leading up to the inner type which
17441 requires additional CV quals, except at the outer level, where const
17442 is not required [conv.qual]. It would be normal to set this flag in
17443 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
17444 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
17445 This is the outermost level of a deduction, and PARM can be more CV
17446 qualified at this point.
17447 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
17448 This is the outermost level of a deduction, and PARM can be less CV
17449 qualified at this point. */
17450
17451 static int
unify(tree tparms,tree targs,tree parm,tree arg,int strict,bool explain_p)17452 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
17453 bool explain_p)
17454 {
17455 int idx;
17456 tree targ;
17457 tree tparm;
17458 int strict_in = strict;
17459
17460 /* I don't think this will do the right thing with respect to types.
17461 But the only case I've seen it in so far has been array bounds, where
17462 signedness is the only information lost, and I think that will be
17463 okay. */
17464 while (TREE_CODE (parm) == NOP_EXPR)
17465 parm = TREE_OPERAND (parm, 0);
17466
17467 if (arg == error_mark_node)
17468 return unify_invalid (explain_p);
17469 if (arg == unknown_type_node
17470 || arg == init_list_type_node)
17471 /* We can't deduce anything from this, but we might get all the
17472 template args from other function args. */
17473 return unify_success (explain_p);
17474
17475 /* If PARM uses template parameters, then we can't bail out here,
17476 even if ARG == PARM, since we won't record unifications for the
17477 template parameters. We might need them if we're trying to
17478 figure out which of two things is more specialized. */
17479 if (arg == parm && !uses_template_parms (parm))
17480 return unify_success (explain_p);
17481
17482 /* Handle init lists early, so the rest of the function can assume
17483 we're dealing with a type. */
17484 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
17485 {
17486 tree elt, elttype;
17487 unsigned i;
17488 tree orig_parm = parm;
17489
17490 /* Replace T with std::initializer_list<T> for deduction. */
17491 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
17492 && flag_deduce_init_list)
17493 parm = listify (parm);
17494
17495 if (!is_std_init_list (parm)
17496 && TREE_CODE (parm) != ARRAY_TYPE)
17497 /* We can only deduce from an initializer list argument if the
17498 parameter is std::initializer_list or an array; otherwise this
17499 is a non-deduced context. */
17500 return unify_success (explain_p);
17501
17502 if (TREE_CODE (parm) == ARRAY_TYPE)
17503 elttype = TREE_TYPE (parm);
17504 else
17505 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
17506
17507 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
17508 {
17509 int elt_strict = strict;
17510
17511 if (elt == error_mark_node)
17512 return unify_invalid (explain_p);
17513
17514 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
17515 {
17516 tree type = TREE_TYPE (elt);
17517 /* It should only be possible to get here for a call. */
17518 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
17519 elt_strict |= maybe_adjust_types_for_deduction
17520 (DEDUCE_CALL, &elttype, &type, elt);
17521 elt = type;
17522 }
17523
17524 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
17525 explain_p);
17526 }
17527
17528 if (TREE_CODE (parm) == ARRAY_TYPE
17529 && deducible_array_bound (TYPE_DOMAIN (parm)))
17530 {
17531 /* Also deduce from the length of the initializer list. */
17532 tree max = size_int (CONSTRUCTOR_NELTS (arg));
17533 tree idx = compute_array_index_type (NULL_TREE, max, tf_none);
17534 if (idx == error_mark_node)
17535 return unify_invalid (explain_p);
17536 return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm),
17537 idx, explain_p);
17538 }
17539
17540 /* If the std::initializer_list<T> deduction worked, replace the
17541 deduced A with std::initializer_list<A>. */
17542 if (orig_parm != parm)
17543 {
17544 idx = TEMPLATE_TYPE_IDX (orig_parm);
17545 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
17546 targ = listify (targ);
17547 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
17548 }
17549 return unify_success (explain_p);
17550 }
17551
17552 /* Immediately reject some pairs that won't unify because of
17553 cv-qualification mismatches. */
17554 if (TREE_CODE (arg) == TREE_CODE (parm)
17555 && TYPE_P (arg)
17556 /* It is the elements of the array which hold the cv quals of an array
17557 type, and the elements might be template type parms. We'll check
17558 when we recurse. */
17559 && TREE_CODE (arg) != ARRAY_TYPE
17560 /* We check the cv-qualifiers when unifying with template type
17561 parameters below. We want to allow ARG `const T' to unify with
17562 PARM `T' for example, when computing which of two templates
17563 is more specialized, for example. */
17564 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
17565 && !check_cv_quals_for_unify (strict_in, arg, parm))
17566 return unify_cv_qual_mismatch (explain_p, parm, arg);
17567
17568 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
17569 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
17570 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
17571 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
17572 strict &= ~UNIFY_ALLOW_DERIVED;
17573 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
17574 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
17575
17576 switch (TREE_CODE (parm))
17577 {
17578 case TYPENAME_TYPE:
17579 case SCOPE_REF:
17580 case UNBOUND_CLASS_TEMPLATE:
17581 /* In a type which contains a nested-name-specifier, template
17582 argument values cannot be deduced for template parameters used
17583 within the nested-name-specifier. */
17584 return unify_success (explain_p);
17585
17586 case TEMPLATE_TYPE_PARM:
17587 case TEMPLATE_TEMPLATE_PARM:
17588 case BOUND_TEMPLATE_TEMPLATE_PARM:
17589 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
17590 if (error_operand_p (tparm))
17591 return unify_invalid (explain_p);
17592
17593 if (TEMPLATE_TYPE_LEVEL (parm)
17594 != template_decl_level (tparm))
17595 /* The PARM is not one we're trying to unify. Just check
17596 to see if it matches ARG. */
17597 {
17598 if (TREE_CODE (arg) == TREE_CODE (parm)
17599 && (is_auto (parm) ? is_auto (arg)
17600 : same_type_p (parm, arg)))
17601 return unify_success (explain_p);
17602 else
17603 return unify_type_mismatch (explain_p, parm, arg);
17604 }
17605 idx = TEMPLATE_TYPE_IDX (parm);
17606 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
17607 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
17608 if (error_operand_p (tparm))
17609 return unify_invalid (explain_p);
17610
17611 /* Check for mixed types and values. */
17612 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
17613 && TREE_CODE (tparm) != TYPE_DECL)
17614 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
17615 && TREE_CODE (tparm) != TEMPLATE_DECL))
17616 gcc_unreachable ();
17617
17618 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
17619 {
17620 /* ARG must be constructed from a template class or a template
17621 template parameter. */
17622 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
17623 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
17624 return unify_template_deduction_failure (explain_p, parm, arg);
17625 {
17626 tree parmvec = TYPE_TI_ARGS (parm);
17627 /* An alias template name is never deduced. */
17628 if (TYPE_ALIAS_P (arg))
17629 arg = strip_typedefs (arg);
17630 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
17631 tree full_argvec = add_to_template_args (targs, argvec);
17632 tree parm_parms
17633 = DECL_INNERMOST_TEMPLATE_PARMS
17634 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
17635 int i, len;
17636 int parm_variadic_p = 0;
17637
17638 /* The resolution to DR150 makes clear that default
17639 arguments for an N-argument may not be used to bind T
17640 to a template template parameter with fewer than N
17641 parameters. It is not safe to permit the binding of
17642 default arguments as an extension, as that may change
17643 the meaning of a conforming program. Consider:
17644
17645 struct Dense { static const unsigned int dim = 1; };
17646
17647 template <template <typename> class View,
17648 typename Block>
17649 void operator+(float, View<Block> const&);
17650
17651 template <typename Block,
17652 unsigned int Dim = Block::dim>
17653 struct Lvalue_proxy { operator float() const; };
17654
17655 void
17656 test_1d (void) {
17657 Lvalue_proxy<Dense> p;
17658 float b;
17659 b + p;
17660 }
17661
17662 Here, if Lvalue_proxy is permitted to bind to View, then
17663 the global operator+ will be used; if they are not, the
17664 Lvalue_proxy will be converted to float. */
17665 if (coerce_template_parms (parm_parms,
17666 full_argvec,
17667 TYPE_TI_TEMPLATE (parm),
17668 (explain_p
17669 ? tf_warning_or_error
17670 : tf_none),
17671 /*require_all_args=*/true,
17672 /*use_default_args=*/false)
17673 == error_mark_node)
17674 return 1;
17675
17676 /* Deduce arguments T, i from TT<T> or TT<i>.
17677 We check each element of PARMVEC and ARGVEC individually
17678 rather than the whole TREE_VEC since they can have
17679 different number of elements. */
17680
17681 parmvec = expand_template_argument_pack (parmvec);
17682 argvec = expand_template_argument_pack (argvec);
17683
17684 len = TREE_VEC_LENGTH (parmvec);
17685
17686 /* Check if the parameters end in a pack, making them
17687 variadic. */
17688 if (len > 0
17689 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
17690 parm_variadic_p = 1;
17691
17692 for (i = 0; i < len - parm_variadic_p; ++i)
17693 /* If the template argument list of P contains a pack
17694 expansion that is not the last template argument, the
17695 entire template argument list is a non-deduced
17696 context. */
17697 if (PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, i)))
17698 return unify_success (explain_p);
17699
17700 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
17701 return unify_too_few_arguments (explain_p,
17702 TREE_VEC_LENGTH (argvec), len);
17703
17704 for (i = 0; i < len - parm_variadic_p; ++i)
17705 {
17706 RECUR_AND_CHECK_FAILURE (tparms, targs,
17707 TREE_VEC_ELT (parmvec, i),
17708 TREE_VEC_ELT (argvec, i),
17709 UNIFY_ALLOW_NONE, explain_p);
17710 }
17711
17712 if (parm_variadic_p
17713 && unify_pack_expansion (tparms, targs,
17714 parmvec, argvec,
17715 DEDUCE_EXACT,
17716 /*subr=*/true, explain_p))
17717 return 1;
17718 }
17719 arg = TYPE_TI_TEMPLATE (arg);
17720
17721 /* Fall through to deduce template name. */
17722 }
17723
17724 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
17725 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
17726 {
17727 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
17728
17729 /* Simple cases: Value already set, does match or doesn't. */
17730 if (targ != NULL_TREE && template_args_equal (targ, arg))
17731 return unify_success (explain_p);
17732 else if (targ)
17733 return unify_inconsistency (explain_p, parm, targ, arg);
17734 }
17735 else
17736 {
17737 /* If PARM is `const T' and ARG is only `int', we don't have
17738 a match unless we are allowing additional qualification.
17739 If ARG is `const int' and PARM is just `T' that's OK;
17740 that binds `const int' to `T'. */
17741 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
17742 arg, parm))
17743 return unify_cv_qual_mismatch (explain_p, parm, arg);
17744
17745 /* Consider the case where ARG is `const volatile int' and
17746 PARM is `const T'. Then, T should be `volatile int'. */
17747 arg = cp_build_qualified_type_real
17748 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
17749 if (arg == error_mark_node)
17750 return unify_invalid (explain_p);
17751
17752 /* Simple cases: Value already set, does match or doesn't. */
17753 if (targ != NULL_TREE && same_type_p (targ, arg))
17754 return unify_success (explain_p);
17755 else if (targ)
17756 return unify_inconsistency (explain_p, parm, targ, arg);
17757
17758 /* Make sure that ARG is not a variable-sized array. (Note
17759 that were talking about variable-sized arrays (like
17760 `int[n]'), rather than arrays of unknown size (like
17761 `int[]').) We'll get very confused by such a type since
17762 the bound of the array is not constant, and therefore
17763 not mangleable. Besides, such types are not allowed in
17764 ISO C++, so we can do as we please here. We do allow
17765 them for 'auto' deduction, since that isn't ABI-exposed. */
17766 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
17767 return unify_vla_arg (explain_p, arg);
17768
17769 /* Strip typedefs as in convert_template_argument. */
17770 arg = canonicalize_type_argument (arg, tf_none);
17771 }
17772
17773 /* If ARG is a parameter pack or an expansion, we cannot unify
17774 against it unless PARM is also a parameter pack. */
17775 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
17776 && !template_parameter_pack_p (parm))
17777 return unify_parameter_pack_mismatch (explain_p, parm, arg);
17778
17779 /* If the argument deduction results is a METHOD_TYPE,
17780 then there is a problem.
17781 METHOD_TYPE doesn't map to any real C++ type the result of
17782 the deduction can not be of that type. */
17783 if (TREE_CODE (arg) == METHOD_TYPE)
17784 return unify_method_type_error (explain_p, arg);
17785
17786 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
17787 return unify_success (explain_p);
17788
17789 case TEMPLATE_PARM_INDEX:
17790 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
17791 if (error_operand_p (tparm))
17792 return unify_invalid (explain_p);
17793
17794 if (TEMPLATE_PARM_LEVEL (parm)
17795 != template_decl_level (tparm))
17796 {
17797 /* The PARM is not one we're trying to unify. Just check
17798 to see if it matches ARG. */
17799 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
17800 && cp_tree_equal (parm, arg));
17801 if (result)
17802 unify_expression_unequal (explain_p, parm, arg);
17803 return result;
17804 }
17805
17806 idx = TEMPLATE_PARM_IDX (parm);
17807 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
17808
17809 if (targ)
17810 {
17811 int x = !cp_tree_equal (targ, arg);
17812 if (x)
17813 unify_inconsistency (explain_p, parm, targ, arg);
17814 return x;
17815 }
17816
17817 /* [temp.deduct.type] If, in the declaration of a function template
17818 with a non-type template-parameter, the non-type
17819 template-parameter is used in an expression in the function
17820 parameter-list and, if the corresponding template-argument is
17821 deduced, the template-argument type shall match the type of the
17822 template-parameter exactly, except that a template-argument
17823 deduced from an array bound may be of any integral type.
17824 The non-type parameter might use already deduced type parameters. */
17825 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
17826 if (!TREE_TYPE (arg))
17827 /* Template-parameter dependent expression. Just accept it for now.
17828 It will later be processed in convert_template_argument. */
17829 ;
17830 else if (same_type_p (TREE_TYPE (arg), tparm))
17831 /* OK */;
17832 else if ((strict & UNIFY_ALLOW_INTEGER)
17833 && CP_INTEGRAL_TYPE_P (tparm))
17834 /* Convert the ARG to the type of PARM; the deduced non-type
17835 template argument must exactly match the types of the
17836 corresponding parameter. */
17837 arg = fold (build_nop (tparm, arg));
17838 else if (uses_template_parms (tparm))
17839 /* We haven't deduced the type of this parameter yet. Try again
17840 later. */
17841 return unify_success (explain_p);
17842 else
17843 return unify_type_mismatch (explain_p, tparm, TREE_TYPE (arg));
17844
17845 /* If ARG is a parameter pack or an expansion, we cannot unify
17846 against it unless PARM is also a parameter pack. */
17847 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
17848 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
17849 return unify_parameter_pack_mismatch (explain_p, parm, arg);
17850
17851 arg = strip_typedefs_expr (arg);
17852 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
17853 return unify_success (explain_p);
17854
17855 case PTRMEM_CST:
17856 {
17857 /* A pointer-to-member constant can be unified only with
17858 another constant. */
17859 if (TREE_CODE (arg) != PTRMEM_CST)
17860 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
17861
17862 /* Just unify the class member. It would be useless (and possibly
17863 wrong, depending on the strict flags) to unify also
17864 PTRMEM_CST_CLASS, because we want to be sure that both parm and
17865 arg refer to the same variable, even if through different
17866 classes. For instance:
17867
17868 struct A { int x; };
17869 struct B : A { };
17870
17871 Unification of &A::x and &B::x must succeed. */
17872 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
17873 PTRMEM_CST_MEMBER (arg), strict, explain_p);
17874 }
17875
17876 case POINTER_TYPE:
17877 {
17878 if (!TYPE_PTR_P (arg))
17879 return unify_type_mismatch (explain_p, parm, arg);
17880
17881 /* [temp.deduct.call]
17882
17883 A can be another pointer or pointer to member type that can
17884 be converted to the deduced A via a qualification
17885 conversion (_conv.qual_).
17886
17887 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
17888 This will allow for additional cv-qualification of the
17889 pointed-to types if appropriate. */
17890
17891 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
17892 /* The derived-to-base conversion only persists through one
17893 level of pointers. */
17894 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
17895
17896 return unify (tparms, targs, TREE_TYPE (parm),
17897 TREE_TYPE (arg), strict, explain_p);
17898 }
17899
17900 case REFERENCE_TYPE:
17901 if (TREE_CODE (arg) != REFERENCE_TYPE)
17902 return unify_type_mismatch (explain_p, parm, arg);
17903 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
17904 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
17905
17906 case ARRAY_TYPE:
17907 if (TREE_CODE (arg) != ARRAY_TYPE)
17908 return unify_type_mismatch (explain_p, parm, arg);
17909 if ((TYPE_DOMAIN (parm) == NULL_TREE)
17910 != (TYPE_DOMAIN (arg) == NULL_TREE))
17911 return unify_type_mismatch (explain_p, parm, arg);
17912 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
17913 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
17914 if (TYPE_DOMAIN (parm) != NULL_TREE)
17915 return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm),
17916 TYPE_DOMAIN (arg), explain_p);
17917 return unify_success (explain_p);
17918
17919 case REAL_TYPE:
17920 case COMPLEX_TYPE:
17921 case VECTOR_TYPE:
17922 case INTEGER_TYPE:
17923 case BOOLEAN_TYPE:
17924 case ENUMERAL_TYPE:
17925 case VOID_TYPE:
17926 case NULLPTR_TYPE:
17927 if (TREE_CODE (arg) != TREE_CODE (parm))
17928 return unify_type_mismatch (explain_p, parm, arg);
17929
17930 /* We have already checked cv-qualification at the top of the
17931 function. */
17932 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
17933 return unify_type_mismatch (explain_p, parm, arg);
17934
17935 /* As far as unification is concerned, this wins. Later checks
17936 will invalidate it if necessary. */
17937 return unify_success (explain_p);
17938
17939 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
17940 /* Type INTEGER_CST can come from ordinary constant template args. */
17941 case INTEGER_CST:
17942 while (TREE_CODE (arg) == NOP_EXPR)
17943 arg = TREE_OPERAND (arg, 0);
17944
17945 if (TREE_CODE (arg) != INTEGER_CST)
17946 return unify_template_argument_mismatch (explain_p, parm, arg);
17947 return (tree_int_cst_equal (parm, arg)
17948 ? unify_success (explain_p)
17949 : unify_template_argument_mismatch (explain_p, parm, arg));
17950
17951 case TREE_VEC:
17952 {
17953 int i, len, argslen;
17954 int parm_variadic_p = 0;
17955
17956 if (TREE_CODE (arg) != TREE_VEC)
17957 return unify_template_argument_mismatch (explain_p, parm, arg);
17958
17959 len = TREE_VEC_LENGTH (parm);
17960 argslen = TREE_VEC_LENGTH (arg);
17961
17962 /* Check for pack expansions in the parameters. */
17963 for (i = 0; i < len; ++i)
17964 {
17965 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
17966 {
17967 if (i == len - 1)
17968 /* We can unify against something with a trailing
17969 parameter pack. */
17970 parm_variadic_p = 1;
17971 else
17972 /* [temp.deduct.type]/9: If the template argument list of
17973 P contains a pack expansion that is not the last
17974 template argument, the entire template argument list
17975 is a non-deduced context. */
17976 return unify_success (explain_p);
17977 }
17978 }
17979
17980 /* If we don't have enough arguments to satisfy the parameters
17981 (not counting the pack expression at the end), or we have
17982 too many arguments for a parameter list that doesn't end in
17983 a pack expression, we can't unify. */
17984 if (parm_variadic_p
17985 ? argslen < len - parm_variadic_p
17986 : argslen != len)
17987 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
17988
17989 /* Unify all of the parameters that precede the (optional)
17990 pack expression. */
17991 for (i = 0; i < len - parm_variadic_p; ++i)
17992 {
17993 RECUR_AND_CHECK_FAILURE (tparms, targs,
17994 TREE_VEC_ELT (parm, i),
17995 TREE_VEC_ELT (arg, i),
17996 UNIFY_ALLOW_NONE, explain_p);
17997 }
17998 if (parm_variadic_p)
17999 return unify_pack_expansion (tparms, targs, parm, arg,
18000 DEDUCE_EXACT,
18001 /*subr=*/true, explain_p);
18002 return unify_success (explain_p);
18003 }
18004
18005 case RECORD_TYPE:
18006 case UNION_TYPE:
18007 if (TREE_CODE (arg) != TREE_CODE (parm))
18008 return unify_type_mismatch (explain_p, parm, arg);
18009
18010 if (TYPE_PTRMEMFUNC_P (parm))
18011 {
18012 if (!TYPE_PTRMEMFUNC_P (arg))
18013 return unify_type_mismatch (explain_p, parm, arg);
18014
18015 return unify (tparms, targs,
18016 TYPE_PTRMEMFUNC_FN_TYPE (parm),
18017 TYPE_PTRMEMFUNC_FN_TYPE (arg),
18018 strict, explain_p);
18019 }
18020
18021 if (CLASSTYPE_TEMPLATE_INFO (parm))
18022 {
18023 tree t = NULL_TREE;
18024
18025 if (strict_in & UNIFY_ALLOW_DERIVED)
18026 {
18027 /* First, we try to unify the PARM and ARG directly. */
18028 t = try_class_unification (tparms, targs,
18029 parm, arg, explain_p);
18030
18031 if (!t)
18032 {
18033 /* Fallback to the special case allowed in
18034 [temp.deduct.call]:
18035
18036 If P is a class, and P has the form
18037 template-id, then A can be a derived class of
18038 the deduced A. Likewise, if P is a pointer to
18039 a class of the form template-id, A can be a
18040 pointer to a derived class pointed to by the
18041 deduced A. */
18042 enum template_base_result r;
18043 r = get_template_base (tparms, targs, parm, arg,
18044 explain_p, &t);
18045
18046 if (!t)
18047 return unify_no_common_base (explain_p, r, parm, arg);
18048 }
18049 }
18050 else if (CLASSTYPE_TEMPLATE_INFO (arg)
18051 && (CLASSTYPE_TI_TEMPLATE (parm)
18052 == CLASSTYPE_TI_TEMPLATE (arg)))
18053 /* Perhaps PARM is something like S<U> and ARG is S<int>.
18054 Then, we should unify `int' and `U'. */
18055 t = arg;
18056 else
18057 /* There's no chance of unification succeeding. */
18058 return unify_type_mismatch (explain_p, parm, arg);
18059
18060 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
18061 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
18062 }
18063 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
18064 return unify_type_mismatch (explain_p, parm, arg);
18065 return unify_success (explain_p);
18066
18067 case METHOD_TYPE:
18068 case FUNCTION_TYPE:
18069 {
18070 unsigned int nargs;
18071 tree *args;
18072 tree a;
18073 unsigned int i;
18074
18075 if (TREE_CODE (arg) != TREE_CODE (parm))
18076 return unify_type_mismatch (explain_p, parm, arg);
18077
18078 /* CV qualifications for methods can never be deduced, they must
18079 match exactly. We need to check them explicitly here,
18080 because type_unification_real treats them as any other
18081 cv-qualified parameter. */
18082 if (TREE_CODE (parm) == METHOD_TYPE
18083 && (!check_cv_quals_for_unify
18084 (UNIFY_ALLOW_NONE,
18085 class_of_this_parm (arg),
18086 class_of_this_parm (parm))))
18087 return unify_cv_qual_mismatch (explain_p, parm, arg);
18088
18089 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
18090 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
18091
18092 nargs = list_length (TYPE_ARG_TYPES (arg));
18093 args = XALLOCAVEC (tree, nargs);
18094 for (a = TYPE_ARG_TYPES (arg), i = 0;
18095 a != NULL_TREE && a != void_list_node;
18096 a = TREE_CHAIN (a), ++i)
18097 args[i] = TREE_VALUE (a);
18098 nargs = i;
18099
18100 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
18101 args, nargs, 1, DEDUCE_EXACT,
18102 LOOKUP_NORMAL, NULL, explain_p);
18103 }
18104
18105 case OFFSET_TYPE:
18106 /* Unify a pointer to member with a pointer to member function, which
18107 deduces the type of the member as a function type. */
18108 if (TYPE_PTRMEMFUNC_P (arg))
18109 {
18110 /* Check top-level cv qualifiers */
18111 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
18112 return unify_cv_qual_mismatch (explain_p, parm, arg);
18113
18114 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
18115 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
18116 UNIFY_ALLOW_NONE, explain_p);
18117
18118 /* Determine the type of the function we are unifying against. */
18119 tree fntype = static_fn_type (arg);
18120
18121 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
18122 }
18123
18124 if (TREE_CODE (arg) != OFFSET_TYPE)
18125 return unify_type_mismatch (explain_p, parm, arg);
18126 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
18127 TYPE_OFFSET_BASETYPE (arg),
18128 UNIFY_ALLOW_NONE, explain_p);
18129 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
18130 strict, explain_p);
18131
18132 case CONST_DECL:
18133 if (DECL_TEMPLATE_PARM_P (parm))
18134 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
18135 if (arg != integral_constant_value (parm))
18136 return unify_template_argument_mismatch (explain_p, parm, arg);
18137 return unify_success (explain_p);
18138
18139 case FIELD_DECL:
18140 case TEMPLATE_DECL:
18141 /* Matched cases are handled by the ARG == PARM test above. */
18142 return unify_template_argument_mismatch (explain_p, parm, arg);
18143
18144 case VAR_DECL:
18145 /* A non-type template parameter that is a variable should be a
18146 an integral constant, in which case, it whould have been
18147 folded into its (constant) value. So we should not be getting
18148 a variable here. */
18149 gcc_unreachable ();
18150
18151 case TYPE_ARGUMENT_PACK:
18152 case NONTYPE_ARGUMENT_PACK:
18153 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
18154 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
18155
18156 case TYPEOF_TYPE:
18157 case DECLTYPE_TYPE:
18158 case UNDERLYING_TYPE:
18159 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
18160 or UNDERLYING_TYPE nodes. */
18161 return unify_success (explain_p);
18162
18163 case ERROR_MARK:
18164 /* Unification fails if we hit an error node. */
18165 return unify_invalid (explain_p);
18166
18167 case INDIRECT_REF:
18168 if (REFERENCE_REF_P (parm))
18169 return unify (tparms, targs, TREE_OPERAND (parm, 0), arg,
18170 strict, explain_p);
18171 /* FALLTHRU */
18172
18173 default:
18174 /* An unresolved overload is a nondeduced context. */
18175 if (is_overloaded_fn (parm) || type_unknown_p (parm))
18176 return unify_success (explain_p);
18177 gcc_assert (EXPR_P (parm));
18178
18179 /* We must be looking at an expression. This can happen with
18180 something like:
18181
18182 template <int I>
18183 void foo(S<I>, S<I + 2>);
18184
18185 This is a "nondeduced context":
18186
18187 [deduct.type]
18188
18189 The nondeduced contexts are:
18190
18191 --A type that is a template-id in which one or more of
18192 the template-arguments is an expression that references
18193 a template-parameter.
18194
18195 In these cases, we assume deduction succeeded, but don't
18196 actually infer any unifications. */
18197
18198 if (!uses_template_parms (parm)
18199 && !template_args_equal (parm, arg))
18200 return unify_expression_unequal (explain_p, parm, arg);
18201 else
18202 return unify_success (explain_p);
18203 }
18204 }
18205 #undef RECUR_AND_CHECK_FAILURE
18206
18207 /* Note that DECL can be defined in this translation unit, if
18208 required. */
18209
18210 static void
mark_definable(tree decl)18211 mark_definable (tree decl)
18212 {
18213 tree clone;
18214 DECL_NOT_REALLY_EXTERN (decl) = 1;
18215 FOR_EACH_CLONE (clone, decl)
18216 DECL_NOT_REALLY_EXTERN (clone) = 1;
18217 }
18218
18219 /* Called if RESULT is explicitly instantiated, or is a member of an
18220 explicitly instantiated class. */
18221
18222 void
mark_decl_instantiated(tree result,int extern_p)18223 mark_decl_instantiated (tree result, int extern_p)
18224 {
18225 SET_DECL_EXPLICIT_INSTANTIATION (result);
18226
18227 /* If this entity has already been written out, it's too late to
18228 make any modifications. */
18229 if (TREE_ASM_WRITTEN (result))
18230 return;
18231
18232 /* For anonymous namespace we don't need to do anything. */
18233 if (decl_anon_ns_mem_p (result))
18234 {
18235 gcc_assert (!TREE_PUBLIC (result));
18236 return;
18237 }
18238
18239 if (TREE_CODE (result) != FUNCTION_DECL)
18240 /* The TREE_PUBLIC flag for function declarations will have been
18241 set correctly by tsubst. */
18242 TREE_PUBLIC (result) = 1;
18243
18244 /* This might have been set by an earlier implicit instantiation. */
18245 DECL_COMDAT (result) = 0;
18246
18247 if (extern_p)
18248 DECL_NOT_REALLY_EXTERN (result) = 0;
18249 else
18250 {
18251 mark_definable (result);
18252 mark_needed (result);
18253 /* Always make artificials weak. */
18254 if (DECL_ARTIFICIAL (result) && flag_weak)
18255 comdat_linkage (result);
18256 /* For WIN32 we also want to put explicit instantiations in
18257 linkonce sections. */
18258 else if (TREE_PUBLIC (result))
18259 maybe_make_one_only (result);
18260 }
18261
18262 /* If EXTERN_P, then this function will not be emitted -- unless
18263 followed by an explicit instantiation, at which point its linkage
18264 will be adjusted. If !EXTERN_P, then this function will be
18265 emitted here. In neither circumstance do we want
18266 import_export_decl to adjust the linkage. */
18267 DECL_INTERFACE_KNOWN (result) = 1;
18268 }
18269
18270 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
18271 important template arguments. If any are missing, we check whether
18272 they're important by using error_mark_node for substituting into any
18273 args that were used for partial ordering (the ones between ARGS and END)
18274 and seeing if it bubbles up. */
18275
18276 static bool
check_undeduced_parms(tree targs,tree args,tree end)18277 check_undeduced_parms (tree targs, tree args, tree end)
18278 {
18279 bool found = false;
18280 int i;
18281 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
18282 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
18283 {
18284 found = true;
18285 TREE_VEC_ELT (targs, i) = error_mark_node;
18286 }
18287 if (found)
18288 {
18289 tree substed = tsubst_arg_types (args, targs, end, tf_none, NULL_TREE);
18290 if (substed == error_mark_node)
18291 return true;
18292 }
18293 return false;
18294 }
18295
18296 /* Given two function templates PAT1 and PAT2, return:
18297
18298 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
18299 -1 if PAT2 is more specialized than PAT1.
18300 0 if neither is more specialized.
18301
18302 LEN indicates the number of parameters we should consider
18303 (defaulted parameters should not be considered).
18304
18305 The 1998 std underspecified function template partial ordering, and
18306 DR214 addresses the issue. We take pairs of arguments, one from
18307 each of the templates, and deduce them against each other. One of
18308 the templates will be more specialized if all the *other*
18309 template's arguments deduce against its arguments and at least one
18310 of its arguments *does* *not* deduce against the other template's
18311 corresponding argument. Deduction is done as for class templates.
18312 The arguments used in deduction have reference and top level cv
18313 qualifiers removed. Iff both arguments were originally reference
18314 types *and* deduction succeeds in both directions, an lvalue reference
18315 wins against an rvalue reference and otherwise the template
18316 with the more cv-qualified argument wins for that pairing (if
18317 neither is more cv-qualified, they both are equal). Unlike regular
18318 deduction, after all the arguments have been deduced in this way,
18319 we do *not* verify the deduced template argument values can be
18320 substituted into non-deduced contexts.
18321
18322 The logic can be a bit confusing here, because we look at deduce1 and
18323 targs1 to see if pat2 is at least as specialized, and vice versa; if we
18324 can find template arguments for pat1 to make arg1 look like arg2, that
18325 means that arg2 is at least as specialized as arg1. */
18326
18327 int
more_specialized_fn(tree pat1,tree pat2,int len)18328 more_specialized_fn (tree pat1, tree pat2, int len)
18329 {
18330 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
18331 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
18332 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
18333 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
18334 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
18335 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
18336 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
18337 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
18338 tree origs1, origs2;
18339 bool lose1 = false;
18340 bool lose2 = false;
18341
18342 /* Remove the this parameter from non-static member functions. If
18343 one is a non-static member function and the other is not a static
18344 member function, remove the first parameter from that function
18345 also. This situation occurs for operator functions where we
18346 locate both a member function (with this pointer) and non-member
18347 operator (with explicit first operand). */
18348 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
18349 {
18350 len--; /* LEN is the number of significant arguments for DECL1 */
18351 args1 = TREE_CHAIN (args1);
18352 if (!DECL_STATIC_FUNCTION_P (decl2))
18353 args2 = TREE_CHAIN (args2);
18354 }
18355 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
18356 {
18357 args2 = TREE_CHAIN (args2);
18358 if (!DECL_STATIC_FUNCTION_P (decl1))
18359 {
18360 len--;
18361 args1 = TREE_CHAIN (args1);
18362 }
18363 }
18364
18365 /* If only one is a conversion operator, they are unordered. */
18366 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
18367 return 0;
18368
18369 /* Consider the return type for a conversion function */
18370 if (DECL_CONV_FN_P (decl1))
18371 {
18372 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
18373 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
18374 len++;
18375 }
18376
18377 processing_template_decl++;
18378
18379 origs1 = args1;
18380 origs2 = args2;
18381
18382 while (len--
18383 /* Stop when an ellipsis is seen. */
18384 && args1 != NULL_TREE && args2 != NULL_TREE)
18385 {
18386 tree arg1 = TREE_VALUE (args1);
18387 tree arg2 = TREE_VALUE (args2);
18388 int deduce1, deduce2;
18389 int quals1 = -1;
18390 int quals2 = -1;
18391 int ref1 = 0;
18392 int ref2 = 0;
18393
18394 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
18395 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
18396 {
18397 /* When both arguments are pack expansions, we need only
18398 unify the patterns themselves. */
18399 arg1 = PACK_EXPANSION_PATTERN (arg1);
18400 arg2 = PACK_EXPANSION_PATTERN (arg2);
18401
18402 /* This is the last comparison we need to do. */
18403 len = 0;
18404 }
18405
18406 if (TREE_CODE (arg1) == REFERENCE_TYPE)
18407 {
18408 ref1 = TYPE_REF_IS_RVALUE (arg1) + 1;
18409 arg1 = TREE_TYPE (arg1);
18410 quals1 = cp_type_quals (arg1);
18411 }
18412
18413 if (TREE_CODE (arg2) == REFERENCE_TYPE)
18414 {
18415 ref2 = TYPE_REF_IS_RVALUE (arg2) + 1;
18416 arg2 = TREE_TYPE (arg2);
18417 quals2 = cp_type_quals (arg2);
18418 }
18419
18420 arg1 = TYPE_MAIN_VARIANT (arg1);
18421 arg2 = TYPE_MAIN_VARIANT (arg2);
18422
18423 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
18424 {
18425 int i, len2 = list_length (args2);
18426 tree parmvec = make_tree_vec (1);
18427 tree argvec = make_tree_vec (len2);
18428 tree ta = args2;
18429
18430 /* Setup the parameter vector, which contains only ARG1. */
18431 TREE_VEC_ELT (parmvec, 0) = arg1;
18432
18433 /* Setup the argument vector, which contains the remaining
18434 arguments. */
18435 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
18436 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
18437
18438 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
18439 argvec, DEDUCE_EXACT,
18440 /*subr=*/true, /*explain_p=*/false)
18441 == 0);
18442
18443 /* We cannot deduce in the other direction, because ARG1 is
18444 a pack expansion but ARG2 is not. */
18445 deduce2 = 0;
18446 }
18447 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
18448 {
18449 int i, len1 = list_length (args1);
18450 tree parmvec = make_tree_vec (1);
18451 tree argvec = make_tree_vec (len1);
18452 tree ta = args1;
18453
18454 /* Setup the parameter vector, which contains only ARG1. */
18455 TREE_VEC_ELT (parmvec, 0) = arg2;
18456
18457 /* Setup the argument vector, which contains the remaining
18458 arguments. */
18459 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
18460 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
18461
18462 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
18463 argvec, DEDUCE_EXACT,
18464 /*subr=*/true, /*explain_p=*/false)
18465 == 0);
18466
18467 /* We cannot deduce in the other direction, because ARG2 is
18468 a pack expansion but ARG1 is not.*/
18469 deduce1 = 0;
18470 }
18471
18472 else
18473 {
18474 /* The normal case, where neither argument is a pack
18475 expansion. */
18476 deduce1 = (unify (tparms1, targs1, arg1, arg2,
18477 UNIFY_ALLOW_NONE, /*explain_p=*/false)
18478 == 0);
18479 deduce2 = (unify (tparms2, targs2, arg2, arg1,
18480 UNIFY_ALLOW_NONE, /*explain_p=*/false)
18481 == 0);
18482 }
18483
18484 /* If we couldn't deduce arguments for tparms1 to make arg1 match
18485 arg2, then arg2 is not as specialized as arg1. */
18486 if (!deduce1)
18487 lose2 = true;
18488 if (!deduce2)
18489 lose1 = true;
18490
18491 /* "If, for a given type, deduction succeeds in both directions
18492 (i.e., the types are identical after the transformations above)
18493 and both P and A were reference types (before being replaced with
18494 the type referred to above):
18495 - if the type from the argument template was an lvalue reference and
18496 the type from the parameter template was not, the argument type is
18497 considered to be more specialized than the other; otherwise,
18498 - if the type from the argument template is more cv-qualified
18499 than the type from the parameter template (as described above),
18500 the argument type is considered to be more specialized than the other;
18501 otherwise,
18502 - neither type is more specialized than the other." */
18503
18504 if (deduce1 && deduce2)
18505 {
18506 if (ref1 && ref2 && ref1 != ref2)
18507 {
18508 if (ref1 > ref2)
18509 lose1 = true;
18510 else
18511 lose2 = true;
18512 }
18513 else if (quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
18514 {
18515 if ((quals1 & quals2) == quals2)
18516 lose2 = true;
18517 if ((quals1 & quals2) == quals1)
18518 lose1 = true;
18519 }
18520 }
18521
18522 if (lose1 && lose2)
18523 /* We've failed to deduce something in either direction.
18524 These must be unordered. */
18525 break;
18526
18527 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
18528 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
18529 /* We have already processed all of the arguments in our
18530 handing of the pack expansion type. */
18531 len = 0;
18532
18533 args1 = TREE_CHAIN (args1);
18534 args2 = TREE_CHAIN (args2);
18535 }
18536
18537 /* "In most cases, all template parameters must have values in order for
18538 deduction to succeed, but for partial ordering purposes a template
18539 parameter may remain without a value provided it is not used in the
18540 types being used for partial ordering."
18541
18542 Thus, if we are missing any of the targs1 we need to substitute into
18543 origs1, then pat2 is not as specialized as pat1. This can happen when
18544 there is a nondeduced context. */
18545 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
18546 lose2 = true;
18547 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
18548 lose1 = true;
18549
18550 processing_template_decl--;
18551
18552 /* All things being equal, if the next argument is a pack expansion
18553 for one function but not for the other, prefer the
18554 non-variadic function. FIXME this is bogus; see c++/41958. */
18555 if (lose1 == lose2
18556 && args1 && TREE_VALUE (args1)
18557 && args2 && TREE_VALUE (args2))
18558 {
18559 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
18560 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
18561 }
18562
18563 if (lose1 == lose2)
18564 return 0;
18565 else if (!lose1)
18566 return 1;
18567 else
18568 return -1;
18569 }
18570
18571 /* Determine which of two partial specializations of TMPL is more
18572 specialized.
18573
18574 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
18575 to the first partial specialization. The TREE_VALUE is the
18576 innermost set of template parameters for the partial
18577 specialization. PAT2 is similar, but for the second template.
18578
18579 Return 1 if the first partial specialization is more specialized;
18580 -1 if the second is more specialized; 0 if neither is more
18581 specialized.
18582
18583 See [temp.class.order] for information about determining which of
18584 two templates is more specialized. */
18585
18586 static int
more_specialized_class(tree tmpl,tree pat1,tree pat2)18587 more_specialized_class (tree tmpl, tree pat1, tree pat2)
18588 {
18589 tree targs;
18590 tree tmpl1, tmpl2;
18591 int winner = 0;
18592 bool any_deductions = false;
18593
18594 tmpl1 = TREE_TYPE (pat1);
18595 tmpl2 = TREE_TYPE (pat2);
18596
18597 /* Just like what happens for functions, if we are ordering between
18598 different class template specializations, we may encounter dependent
18599 types in the arguments, and we need our dependency check functions
18600 to behave correctly. */
18601 ++processing_template_decl;
18602 targs = get_class_bindings (tmpl, TREE_VALUE (pat1),
18603 CLASSTYPE_TI_ARGS (tmpl1),
18604 CLASSTYPE_TI_ARGS (tmpl2));
18605 if (targs)
18606 {
18607 --winner;
18608 any_deductions = true;
18609 }
18610
18611 targs = get_class_bindings (tmpl, TREE_VALUE (pat2),
18612 CLASSTYPE_TI_ARGS (tmpl2),
18613 CLASSTYPE_TI_ARGS (tmpl1));
18614 if (targs)
18615 {
18616 ++winner;
18617 any_deductions = true;
18618 }
18619 --processing_template_decl;
18620
18621 /* In the case of a tie where at least one of the class templates
18622 has a parameter pack at the end, the template with the most
18623 non-packed parameters wins. */
18624 if (winner == 0
18625 && any_deductions
18626 && (template_args_variadic_p (TREE_PURPOSE (pat1))
18627 || template_args_variadic_p (TREE_PURPOSE (pat2))))
18628 {
18629 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
18630 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
18631 int len1 = TREE_VEC_LENGTH (args1);
18632 int len2 = TREE_VEC_LENGTH (args2);
18633
18634 /* We don't count the pack expansion at the end. */
18635 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
18636 --len1;
18637 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
18638 --len2;
18639
18640 if (len1 > len2)
18641 return 1;
18642 else if (len1 < len2)
18643 return -1;
18644 }
18645
18646 return winner;
18647 }
18648
18649 /* Return the template arguments that will produce the function signature
18650 DECL from the function template FN, with the explicit template
18651 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
18652 also match. Return NULL_TREE if no satisfactory arguments could be
18653 found. */
18654
18655 static tree
get_bindings(tree fn,tree decl,tree explicit_args,bool check_rettype)18656 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
18657 {
18658 int ntparms = DECL_NTPARMS (fn);
18659 tree targs = make_tree_vec (ntparms);
18660 tree decl_type = TREE_TYPE (decl);
18661 tree decl_arg_types;
18662 tree *args;
18663 unsigned int nargs, ix;
18664 tree arg;
18665
18666 gcc_assert (decl != DECL_TEMPLATE_RESULT (fn));
18667
18668 /* Never do unification on the 'this' parameter. */
18669 decl_arg_types = skip_artificial_parms_for (decl,
18670 TYPE_ARG_TYPES (decl_type));
18671
18672 nargs = list_length (decl_arg_types);
18673 args = XALLOCAVEC (tree, nargs);
18674 for (arg = decl_arg_types, ix = 0;
18675 arg != NULL_TREE && arg != void_list_node;
18676 arg = TREE_CHAIN (arg), ++ix)
18677 args[ix] = TREE_VALUE (arg);
18678
18679 if (fn_type_unification (fn, explicit_args, targs,
18680 args, ix,
18681 (check_rettype || DECL_CONV_FN_P (fn)
18682 ? TREE_TYPE (decl_type) : NULL_TREE),
18683 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false,
18684 /*decltype*/false)
18685 == error_mark_node)
18686 return NULL_TREE;
18687
18688 return targs;
18689 }
18690
18691 /* Return the innermost template arguments that, when applied to a partial
18692 specialization of TMPL whose innermost template parameters are
18693 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
18694 ARGS.
18695
18696 For example, suppose we have:
18697
18698 template <class T, class U> struct S {};
18699 template <class T> struct S<T*, int> {};
18700
18701 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
18702 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
18703 int}. The resulting vector will be {double}, indicating that `T'
18704 is bound to `double'. */
18705
18706 static tree
get_class_bindings(tree tmpl,tree tparms,tree spec_args,tree args)18707 get_class_bindings (tree tmpl, tree tparms, tree spec_args, tree args)
18708 {
18709 int i, ntparms = TREE_VEC_LENGTH (tparms);
18710 tree deduced_args;
18711 tree innermost_deduced_args;
18712
18713 innermost_deduced_args = make_tree_vec (ntparms);
18714 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
18715 {
18716 deduced_args = copy_node (args);
18717 SET_TMPL_ARGS_LEVEL (deduced_args,
18718 TMPL_ARGS_DEPTH (deduced_args),
18719 innermost_deduced_args);
18720 }
18721 else
18722 deduced_args = innermost_deduced_args;
18723
18724 if (unify (tparms, deduced_args,
18725 INNERMOST_TEMPLATE_ARGS (spec_args),
18726 INNERMOST_TEMPLATE_ARGS (args),
18727 UNIFY_ALLOW_NONE, /*explain_p=*/false))
18728 return NULL_TREE;
18729
18730 for (i = 0; i < ntparms; ++i)
18731 if (! TREE_VEC_ELT (innermost_deduced_args, i))
18732 return NULL_TREE;
18733
18734 /* Verify that nondeduced template arguments agree with the type
18735 obtained from argument deduction.
18736
18737 For example:
18738
18739 struct A { typedef int X; };
18740 template <class T, class U> struct C {};
18741 template <class T> struct C<T, typename T::X> {};
18742
18743 Then with the instantiation `C<A, int>', we can deduce that
18744 `T' is `A' but unify () does not check whether `typename T::X'
18745 is `int'. */
18746 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
18747 spec_args = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
18748 spec_args, tmpl,
18749 tf_none, false, false);
18750 if (spec_args == error_mark_node
18751 /* We only need to check the innermost arguments; the other
18752 arguments will always agree. */
18753 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
18754 INNERMOST_TEMPLATE_ARGS (args)))
18755 return NULL_TREE;
18756
18757 /* Now that we have bindings for all of the template arguments,
18758 ensure that the arguments deduced for the template template
18759 parameters have compatible template parameter lists. See the use
18760 of template_template_parm_bindings_ok_p in fn_type_unification
18761 for more information. */
18762 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
18763 return NULL_TREE;
18764
18765 return deduced_args;
18766 }
18767
18768 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
18769 Return the TREE_LIST node with the most specialized template, if
18770 any. If there is no most specialized template, the error_mark_node
18771 is returned.
18772
18773 Note that this function does not look at, or modify, the
18774 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
18775 returned is one of the elements of INSTANTIATIONS, callers may
18776 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
18777 and retrieve it from the value returned. */
18778
18779 tree
most_specialized_instantiation(tree templates)18780 most_specialized_instantiation (tree templates)
18781 {
18782 tree fn, champ;
18783
18784 ++processing_template_decl;
18785
18786 champ = templates;
18787 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
18788 {
18789 int fate = 0;
18790
18791 if (get_bindings (TREE_VALUE (champ),
18792 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
18793 NULL_TREE, /*check_ret=*/true))
18794 fate--;
18795
18796 if (get_bindings (TREE_VALUE (fn),
18797 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
18798 NULL_TREE, /*check_ret=*/true))
18799 fate++;
18800
18801 if (fate == -1)
18802 champ = fn;
18803 else if (!fate)
18804 {
18805 /* Equally specialized, move to next function. If there
18806 is no next function, nothing's most specialized. */
18807 fn = TREE_CHAIN (fn);
18808 champ = fn;
18809 if (!fn)
18810 break;
18811 }
18812 }
18813
18814 if (champ)
18815 /* Now verify that champ is better than everything earlier in the
18816 instantiation list. */
18817 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
18818 if (get_bindings (TREE_VALUE (champ),
18819 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
18820 NULL_TREE, /*check_ret=*/true)
18821 || !get_bindings (TREE_VALUE (fn),
18822 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
18823 NULL_TREE, /*check_ret=*/true))
18824 {
18825 champ = NULL_TREE;
18826 break;
18827 }
18828
18829 processing_template_decl--;
18830
18831 if (!champ)
18832 return error_mark_node;
18833
18834 return champ;
18835 }
18836
18837 /* If DECL is a specialization of some template, return the most
18838 general such template. Otherwise, returns NULL_TREE.
18839
18840 For example, given:
18841
18842 template <class T> struct S { template <class U> void f(U); };
18843
18844 if TMPL is `template <class U> void S<int>::f(U)' this will return
18845 the full template. This function will not trace past partial
18846 specializations, however. For example, given in addition:
18847
18848 template <class T> struct S<T*> { template <class U> void f(U); };
18849
18850 if TMPL is `template <class U> void S<int*>::f(U)' this will return
18851 `template <class T> template <class U> S<T*>::f(U)'. */
18852
18853 tree
most_general_template(tree decl)18854 most_general_template (tree decl)
18855 {
18856 if (TREE_CODE (decl) != TEMPLATE_DECL)
18857 {
18858 if (tree tinfo = get_template_info (decl))
18859 decl = TI_TEMPLATE (tinfo);
18860 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
18861 template friend, or a FIELD_DECL for a capture pack. */
18862 if (TREE_CODE (decl) != TEMPLATE_DECL)
18863 return NULL_TREE;
18864 }
18865
18866 /* Look for more and more general templates. */
18867 while (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl))
18868 {
18869 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
18870 (See cp-tree.h for details.) */
18871 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
18872 break;
18873
18874 if (CLASS_TYPE_P (TREE_TYPE (decl))
18875 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
18876 break;
18877
18878 /* Stop if we run into an explicitly specialized class template. */
18879 if (!DECL_NAMESPACE_SCOPE_P (decl)
18880 && DECL_CONTEXT (decl)
18881 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
18882 break;
18883
18884 decl = DECL_TI_TEMPLATE (decl);
18885 }
18886
18887 return decl;
18888 }
18889
18890 /* Return the most specialized of the class template partial
18891 specializations which can produce TYPE, a specialization of some class
18892 template. The value returned is actually a TREE_LIST; the TREE_TYPE is
18893 a _TYPE node corresponding to the partial specialization, while the
18894 TREE_PURPOSE is the set of template arguments that must be
18895 substituted into the TREE_TYPE in order to generate TYPE.
18896
18897 If the choice of partial specialization is ambiguous, a diagnostic
18898 is issued, and the error_mark_node is returned. If there are no
18899 partial specializations matching TYPE, then NULL_TREE is
18900 returned, indicating that the primary template should be used. */
18901
18902 static tree
most_specialized_class(tree type,tsubst_flags_t complain)18903 most_specialized_class (tree type, tsubst_flags_t complain)
18904 {
18905 tree list = NULL_TREE;
18906 tree t;
18907 tree champ;
18908 int fate;
18909 bool ambiguous_p;
18910 tree outer_args = NULL_TREE;
18911
18912 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
18913 tree main_tmpl = most_general_template (tmpl);
18914 tree args = CLASSTYPE_TI_ARGS (type);
18915
18916 /* For determining which partial specialization to use, only the
18917 innermost args are interesting. */
18918 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
18919 {
18920 outer_args = strip_innermost_template_args (args, 1);
18921 args = INNERMOST_TEMPLATE_ARGS (args);
18922 }
18923
18924 for (t = DECL_TEMPLATE_SPECIALIZATIONS (main_tmpl); t; t = TREE_CHAIN (t))
18925 {
18926 tree partial_spec_args;
18927 tree spec_args;
18928 tree spec_tmpl = TREE_VALUE (t);
18929 tree orig_parms = DECL_INNERMOST_TEMPLATE_PARMS (spec_tmpl);
18930
18931 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
18932
18933 ++processing_template_decl;
18934
18935 if (outer_args)
18936 {
18937 /* Discard the outer levels of args, and then substitute in the
18938 template args from the enclosing class. */
18939 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
18940 partial_spec_args = tsubst_template_args
18941 (partial_spec_args, outer_args, tf_none, NULL_TREE);
18942
18943 /* And the same for the partial specialization TEMPLATE_DECL. */
18944 spec_tmpl = tsubst (spec_tmpl, outer_args, tf_none, NULL_TREE);
18945 }
18946
18947 partial_spec_args =
18948 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
18949 partial_spec_args,
18950 tmpl, tf_none,
18951 /*require_all_args=*/true,
18952 /*use_default_args=*/true);
18953
18954 --processing_template_decl;
18955
18956 if (partial_spec_args == error_mark_node)
18957 return error_mark_node;
18958 if (spec_tmpl == error_mark_node)
18959 return error_mark_node;
18960
18961 tree parms = DECL_INNERMOST_TEMPLATE_PARMS (spec_tmpl);
18962 spec_args = get_class_bindings (tmpl, parms,
18963 partial_spec_args,
18964 args);
18965 if (spec_args)
18966 {
18967 if (outer_args)
18968 spec_args = add_to_template_args (outer_args, spec_args);
18969 list = tree_cons (spec_args, orig_parms, list);
18970 TREE_TYPE (list) = TREE_TYPE (t);
18971 }
18972 }
18973
18974 if (! list)
18975 return NULL_TREE;
18976
18977 ambiguous_p = false;
18978 t = list;
18979 champ = t;
18980 t = TREE_CHAIN (t);
18981 for (; t; t = TREE_CHAIN (t))
18982 {
18983 fate = more_specialized_class (tmpl, champ, t);
18984 if (fate == 1)
18985 ;
18986 else
18987 {
18988 if (fate == 0)
18989 {
18990 t = TREE_CHAIN (t);
18991 if (! t)
18992 {
18993 ambiguous_p = true;
18994 break;
18995 }
18996 }
18997 champ = t;
18998 }
18999 }
19000
19001 if (!ambiguous_p)
19002 for (t = list; t && t != champ; t = TREE_CHAIN (t))
19003 {
19004 fate = more_specialized_class (tmpl, champ, t);
19005 if (fate != 1)
19006 {
19007 ambiguous_p = true;
19008 break;
19009 }
19010 }
19011
19012 if (ambiguous_p)
19013 {
19014 const char *str;
19015 char *spaces = NULL;
19016 if (!(complain & tf_error))
19017 return error_mark_node;
19018 error ("ambiguous class template instantiation for %q#T", type);
19019 str = ngettext ("candidate is:", "candidates are:", list_length (list));
19020 for (t = list; t; t = TREE_CHAIN (t))
19021 {
19022 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
19023 spaces = spaces ? spaces : get_spaces (str);
19024 }
19025 free (spaces);
19026 return error_mark_node;
19027 }
19028
19029 return champ;
19030 }
19031
19032 /* Explicitly instantiate DECL. */
19033
19034 void
do_decl_instantiation(tree decl,tree storage)19035 do_decl_instantiation (tree decl, tree storage)
19036 {
19037 tree result = NULL_TREE;
19038 int extern_p = 0;
19039
19040 if (!decl || decl == error_mark_node)
19041 /* An error occurred, for which grokdeclarator has already issued
19042 an appropriate message. */
19043 return;
19044 else if (! DECL_LANG_SPECIFIC (decl))
19045 {
19046 error ("explicit instantiation of non-template %q#D", decl);
19047 return;
19048 }
19049 else if (VAR_P (decl))
19050 {
19051 /* There is an asymmetry here in the way VAR_DECLs and
19052 FUNCTION_DECLs are handled by grokdeclarator. In the case of
19053 the latter, the DECL we get back will be marked as a
19054 template instantiation, and the appropriate
19055 DECL_TEMPLATE_INFO will be set up. This does not happen for
19056 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
19057 should handle VAR_DECLs as it currently handles
19058 FUNCTION_DECLs. */
19059 if (!DECL_CLASS_SCOPE_P (decl))
19060 {
19061 error ("%qD is not a static data member of a class template", decl);
19062 return;
19063 }
19064 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
19065 if (!result || !VAR_P (result))
19066 {
19067 error ("no matching template for %qD found", decl);
19068 return;
19069 }
19070 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
19071 {
19072 error ("type %qT for explicit instantiation %qD does not match "
19073 "declared type %qT", TREE_TYPE (result), decl,
19074 TREE_TYPE (decl));
19075 return;
19076 }
19077 }
19078 else if (TREE_CODE (decl) != FUNCTION_DECL)
19079 {
19080 error ("explicit instantiation of %q#D", decl);
19081 return;
19082 }
19083 else
19084 result = decl;
19085
19086 /* Check for various error cases. Note that if the explicit
19087 instantiation is valid the RESULT will currently be marked as an
19088 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
19089 until we get here. */
19090
19091 if (DECL_TEMPLATE_SPECIALIZATION (result))
19092 {
19093 /* DR 259 [temp.spec].
19094
19095 Both an explicit instantiation and a declaration of an explicit
19096 specialization shall not appear in a program unless the explicit
19097 instantiation follows a declaration of the explicit specialization.
19098
19099 For a given set of template parameters, if an explicit
19100 instantiation of a template appears after a declaration of an
19101 explicit specialization for that template, the explicit
19102 instantiation has no effect. */
19103 return;
19104 }
19105 else if (DECL_EXPLICIT_INSTANTIATION (result))
19106 {
19107 /* [temp.spec]
19108
19109 No program shall explicitly instantiate any template more
19110 than once.
19111
19112 We check DECL_NOT_REALLY_EXTERN so as not to complain when
19113 the first instantiation was `extern' and the second is not,
19114 and EXTERN_P for the opposite case. */
19115 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
19116 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
19117 /* If an "extern" explicit instantiation follows an ordinary
19118 explicit instantiation, the template is instantiated. */
19119 if (extern_p)
19120 return;
19121 }
19122 else if (!DECL_IMPLICIT_INSTANTIATION (result))
19123 {
19124 error ("no matching template for %qD found", result);
19125 return;
19126 }
19127 else if (!DECL_TEMPLATE_INFO (result))
19128 {
19129 permerror (input_location, "explicit instantiation of non-template %q#D", result);
19130 return;
19131 }
19132
19133 if (storage == NULL_TREE)
19134 ;
19135 else if (storage == ridpointers[(int) RID_EXTERN])
19136 {
19137 if (!in_system_header_at (input_location) && (cxx_dialect == cxx98))
19138 pedwarn (input_location, OPT_Wpedantic,
19139 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
19140 "instantiations");
19141 extern_p = 1;
19142 }
19143 else
19144 error ("storage class %qD applied to template instantiation", storage);
19145
19146 check_explicit_instantiation_namespace (result);
19147 mark_decl_instantiated (result, extern_p);
19148 if (! extern_p)
19149 instantiate_decl (result, /*defer_ok=*/1,
19150 /*expl_inst_class_mem_p=*/false);
19151 }
19152
19153 static void
mark_class_instantiated(tree t,int extern_p)19154 mark_class_instantiated (tree t, int extern_p)
19155 {
19156 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
19157 SET_CLASSTYPE_INTERFACE_KNOWN (t);
19158 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
19159 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
19160 if (! extern_p)
19161 {
19162 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
19163 rest_of_type_compilation (t, 1);
19164 }
19165 }
19166
19167 /* Called from do_type_instantiation through binding_table_foreach to
19168 do recursive instantiation for the type bound in ENTRY. */
19169 static void
bt_instantiate_type_proc(binding_entry entry,void * data)19170 bt_instantiate_type_proc (binding_entry entry, void *data)
19171 {
19172 tree storage = *(tree *) data;
19173
19174 if (MAYBE_CLASS_TYPE_P (entry->type)
19175 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
19176 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
19177 }
19178
19179 /* Called from do_type_instantiation to instantiate a member
19180 (a member function or a static member variable) of an
19181 explicitly instantiated class template. */
19182 static void
instantiate_class_member(tree decl,int extern_p)19183 instantiate_class_member (tree decl, int extern_p)
19184 {
19185 mark_decl_instantiated (decl, extern_p);
19186 if (! extern_p)
19187 instantiate_decl (decl, /*defer_ok=*/1,
19188 /*expl_inst_class_mem_p=*/true);
19189 }
19190
19191 /* Perform an explicit instantiation of template class T. STORAGE, if
19192 non-null, is the RID for extern, inline or static. COMPLAIN is
19193 nonzero if this is called from the parser, zero if called recursively,
19194 since the standard is unclear (as detailed below). */
19195
19196 void
do_type_instantiation(tree t,tree storage,tsubst_flags_t complain)19197 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
19198 {
19199 int extern_p = 0;
19200 int nomem_p = 0;
19201 int static_p = 0;
19202 int previous_instantiation_extern_p = 0;
19203
19204 if (TREE_CODE (t) == TYPE_DECL)
19205 t = TREE_TYPE (t);
19206
19207 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
19208 {
19209 tree tmpl =
19210 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
19211 if (tmpl)
19212 error ("explicit instantiation of non-class template %qD", tmpl);
19213 else
19214 error ("explicit instantiation of non-template type %qT", t);
19215 return;
19216 }
19217
19218 complete_type (t);
19219
19220 if (!COMPLETE_TYPE_P (t))
19221 {
19222 if (complain & tf_error)
19223 error ("explicit instantiation of %q#T before definition of template",
19224 t);
19225 return;
19226 }
19227
19228 if (storage != NULL_TREE)
19229 {
19230 if (!in_system_header_at (input_location))
19231 {
19232 if (storage == ridpointers[(int) RID_EXTERN])
19233 {
19234 if (cxx_dialect == cxx98)
19235 pedwarn (input_location, OPT_Wpedantic,
19236 "ISO C++ 1998 forbids the use of %<extern%> on "
19237 "explicit instantiations");
19238 }
19239 else
19240 pedwarn (input_location, OPT_Wpedantic,
19241 "ISO C++ forbids the use of %qE"
19242 " on explicit instantiations", storage);
19243 }
19244
19245 if (storage == ridpointers[(int) RID_INLINE])
19246 nomem_p = 1;
19247 else if (storage == ridpointers[(int) RID_EXTERN])
19248 extern_p = 1;
19249 else if (storage == ridpointers[(int) RID_STATIC])
19250 static_p = 1;
19251 else
19252 {
19253 error ("storage class %qD applied to template instantiation",
19254 storage);
19255 extern_p = 0;
19256 }
19257 }
19258
19259 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
19260 {
19261 /* DR 259 [temp.spec].
19262
19263 Both an explicit instantiation and a declaration of an explicit
19264 specialization shall not appear in a program unless the explicit
19265 instantiation follows a declaration of the explicit specialization.
19266
19267 For a given set of template parameters, if an explicit
19268 instantiation of a template appears after a declaration of an
19269 explicit specialization for that template, the explicit
19270 instantiation has no effect. */
19271 return;
19272 }
19273 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
19274 {
19275 /* [temp.spec]
19276
19277 No program shall explicitly instantiate any template more
19278 than once.
19279
19280 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
19281 instantiation was `extern'. If EXTERN_P then the second is.
19282 These cases are OK. */
19283 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
19284
19285 if (!previous_instantiation_extern_p && !extern_p
19286 && (complain & tf_error))
19287 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
19288
19289 /* If we've already instantiated the template, just return now. */
19290 if (!CLASSTYPE_INTERFACE_ONLY (t))
19291 return;
19292 }
19293
19294 check_explicit_instantiation_namespace (TYPE_NAME (t));
19295 mark_class_instantiated (t, extern_p);
19296
19297 if (nomem_p)
19298 return;
19299
19300 {
19301 tree tmp;
19302
19303 /* In contrast to implicit instantiation, where only the
19304 declarations, and not the definitions, of members are
19305 instantiated, we have here:
19306
19307 [temp.explicit]
19308
19309 The explicit instantiation of a class template specialization
19310 implies the instantiation of all of its members not
19311 previously explicitly specialized in the translation unit
19312 containing the explicit instantiation.
19313
19314 Of course, we can't instantiate member template classes, since
19315 we don't have any arguments for them. Note that the standard
19316 is unclear on whether the instantiation of the members are
19317 *explicit* instantiations or not. However, the most natural
19318 interpretation is that it should be an explicit instantiation. */
19319
19320 if (! static_p)
19321 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
19322 if (TREE_CODE (tmp) == FUNCTION_DECL
19323 && DECL_TEMPLATE_INSTANTIATION (tmp))
19324 instantiate_class_member (tmp, extern_p);
19325
19326 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
19327 if (VAR_P (tmp) && DECL_TEMPLATE_INSTANTIATION (tmp))
19328 instantiate_class_member (tmp, extern_p);
19329
19330 if (CLASSTYPE_NESTED_UTDS (t))
19331 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
19332 bt_instantiate_type_proc, &storage);
19333 }
19334 }
19335
19336 /* Given a function DECL, which is a specialization of TMPL, modify
19337 DECL to be a re-instantiation of TMPL with the same template
19338 arguments. TMPL should be the template into which tsubst'ing
19339 should occur for DECL, not the most general template.
19340
19341 One reason for doing this is a scenario like this:
19342
19343 template <class T>
19344 void f(const T&, int i);
19345
19346 void g() { f(3, 7); }
19347
19348 template <class T>
19349 void f(const T& t, const int i) { }
19350
19351 Note that when the template is first instantiated, with
19352 instantiate_template, the resulting DECL will have no name for the
19353 first parameter, and the wrong type for the second. So, when we go
19354 to instantiate the DECL, we regenerate it. */
19355
19356 static void
regenerate_decl_from_template(tree decl,tree tmpl)19357 regenerate_decl_from_template (tree decl, tree tmpl)
19358 {
19359 /* The arguments used to instantiate DECL, from the most general
19360 template. */
19361 tree args;
19362 tree code_pattern;
19363
19364 args = DECL_TI_ARGS (decl);
19365 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
19366
19367 /* Make sure that we can see identifiers, and compute access
19368 correctly. */
19369 push_access_scope (decl);
19370
19371 if (TREE_CODE (decl) == FUNCTION_DECL)
19372 {
19373 tree decl_parm;
19374 tree pattern_parm;
19375 tree specs;
19376 int args_depth;
19377 int parms_depth;
19378
19379 args_depth = TMPL_ARGS_DEPTH (args);
19380 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
19381 if (args_depth > parms_depth)
19382 args = get_innermost_template_args (args, parms_depth);
19383
19384 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
19385 args, tf_error, NULL_TREE,
19386 /*defer_ok*/false);
19387 if (specs && specs != error_mark_node)
19388 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
19389 specs);
19390
19391 /* Merge parameter declarations. */
19392 decl_parm = skip_artificial_parms_for (decl,
19393 DECL_ARGUMENTS (decl));
19394 pattern_parm
19395 = skip_artificial_parms_for (code_pattern,
19396 DECL_ARGUMENTS (code_pattern));
19397 while (decl_parm && !DECL_PACK_P (pattern_parm))
19398 {
19399 tree parm_type;
19400 tree attributes;
19401
19402 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
19403 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
19404 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
19405 NULL_TREE);
19406 parm_type = type_decays_to (parm_type);
19407 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
19408 TREE_TYPE (decl_parm) = parm_type;
19409 attributes = DECL_ATTRIBUTES (pattern_parm);
19410 if (DECL_ATTRIBUTES (decl_parm) != attributes)
19411 {
19412 DECL_ATTRIBUTES (decl_parm) = attributes;
19413 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
19414 }
19415 decl_parm = DECL_CHAIN (decl_parm);
19416 pattern_parm = DECL_CHAIN (pattern_parm);
19417 }
19418 /* Merge any parameters that match with the function parameter
19419 pack. */
19420 if (pattern_parm && DECL_PACK_P (pattern_parm))
19421 {
19422 int i, len;
19423 tree expanded_types;
19424 /* Expand the TYPE_PACK_EXPANSION that provides the types for
19425 the parameters in this function parameter pack. */
19426 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
19427 args, tf_error, NULL_TREE);
19428 len = TREE_VEC_LENGTH (expanded_types);
19429 for (i = 0; i < len; i++)
19430 {
19431 tree parm_type;
19432 tree attributes;
19433
19434 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
19435 /* Rename the parameter to include the index. */
19436 DECL_NAME (decl_parm) =
19437 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
19438 parm_type = TREE_VEC_ELT (expanded_types, i);
19439 parm_type = type_decays_to (parm_type);
19440 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
19441 TREE_TYPE (decl_parm) = parm_type;
19442 attributes = DECL_ATTRIBUTES (pattern_parm);
19443 if (DECL_ATTRIBUTES (decl_parm) != attributes)
19444 {
19445 DECL_ATTRIBUTES (decl_parm) = attributes;
19446 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
19447 }
19448 decl_parm = DECL_CHAIN (decl_parm);
19449 }
19450 }
19451 /* Merge additional specifiers from the CODE_PATTERN. */
19452 if (DECL_DECLARED_INLINE_P (code_pattern)
19453 && !DECL_DECLARED_INLINE_P (decl))
19454 DECL_DECLARED_INLINE_P (decl) = 1;
19455 }
19456 else if (VAR_P (decl))
19457 {
19458 DECL_INITIAL (decl) =
19459 tsubst_expr (DECL_INITIAL (code_pattern), args,
19460 tf_error, DECL_TI_TEMPLATE (decl),
19461 /*integral_constant_expression_p=*/false);
19462 if (VAR_HAD_UNKNOWN_BOUND (decl))
19463 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
19464 tf_error, DECL_TI_TEMPLATE (decl));
19465 }
19466 else
19467 gcc_unreachable ();
19468
19469 pop_access_scope (decl);
19470 }
19471
19472 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
19473 substituted to get DECL. */
19474
19475 tree
template_for_substitution(tree decl)19476 template_for_substitution (tree decl)
19477 {
19478 tree tmpl = DECL_TI_TEMPLATE (decl);
19479
19480 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
19481 for the instantiation. This is not always the most general
19482 template. Consider, for example:
19483
19484 template <class T>
19485 struct S { template <class U> void f();
19486 template <> void f<int>(); };
19487
19488 and an instantiation of S<double>::f<int>. We want TD to be the
19489 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
19490 while (/* An instantiation cannot have a definition, so we need a
19491 more general template. */
19492 DECL_TEMPLATE_INSTANTIATION (tmpl)
19493 /* We must also deal with friend templates. Given:
19494
19495 template <class T> struct S {
19496 template <class U> friend void f() {};
19497 };
19498
19499 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
19500 so far as the language is concerned, but that's still
19501 where we get the pattern for the instantiation from. On
19502 other hand, if the definition comes outside the class, say:
19503
19504 template <class T> struct S {
19505 template <class U> friend void f();
19506 };
19507 template <class U> friend void f() {}
19508
19509 we don't need to look any further. That's what the check for
19510 DECL_INITIAL is for. */
19511 || (TREE_CODE (decl) == FUNCTION_DECL
19512 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
19513 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
19514 {
19515 /* The present template, TD, should not be a definition. If it
19516 were a definition, we should be using it! Note that we
19517 cannot restructure the loop to just keep going until we find
19518 a template with a definition, since that might go too far if
19519 a specialization was declared, but not defined. */
19520 gcc_assert (!VAR_P (decl)
19521 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
19522
19523 /* Fetch the more general template. */
19524 tmpl = DECL_TI_TEMPLATE (tmpl);
19525 }
19526
19527 return tmpl;
19528 }
19529
19530 /* Returns true if we need to instantiate this template instance even if we
19531 know we aren't going to emit it.. */
19532
19533 bool
always_instantiate_p(tree decl)19534 always_instantiate_p (tree decl)
19535 {
19536 /* We always instantiate inline functions so that we can inline them. An
19537 explicit instantiation declaration prohibits implicit instantiation of
19538 non-inline functions. With high levels of optimization, we would
19539 normally inline non-inline functions -- but we're not allowed to do
19540 that for "extern template" functions. Therefore, we check
19541 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
19542 return ((TREE_CODE (decl) == FUNCTION_DECL
19543 && (DECL_DECLARED_INLINE_P (decl)
19544 || type_uses_auto (TREE_TYPE (TREE_TYPE (decl)))))
19545 /* And we need to instantiate static data members so that
19546 their initializers are available in integral constant
19547 expressions. */
19548 || (VAR_P (decl)
19549 && decl_maybe_constant_var_p (decl)));
19550 }
19551
19552 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
19553 instantiate it now, modifying TREE_TYPE (fn). */
19554
19555 void
maybe_instantiate_noexcept(tree fn)19556 maybe_instantiate_noexcept (tree fn)
19557 {
19558 tree fntype, spec, noex, clone;
19559
19560 /* Don't instantiate a noexcept-specification from template context. */
19561 if (processing_template_decl)
19562 return;
19563
19564 if (DECL_CLONED_FUNCTION_P (fn))
19565 fn = DECL_CLONED_FUNCTION (fn);
19566 fntype = TREE_TYPE (fn);
19567 spec = TYPE_RAISES_EXCEPTIONS (fntype);
19568
19569 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
19570 return;
19571
19572 noex = TREE_PURPOSE (spec);
19573
19574 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
19575 {
19576 if (push_tinst_level (fn))
19577 {
19578 push_access_scope (fn);
19579 push_deferring_access_checks (dk_no_deferred);
19580 input_location = DECL_SOURCE_LOCATION (fn);
19581 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
19582 DEFERRED_NOEXCEPT_ARGS (noex),
19583 tf_warning_or_error, fn,
19584 /*function_p=*/false,
19585 /*integral_constant_expression_p=*/true);
19586 pop_deferring_access_checks ();
19587 pop_access_scope (fn);
19588 pop_tinst_level ();
19589 spec = build_noexcept_spec (noex, tf_warning_or_error);
19590 if (spec == error_mark_node)
19591 spec = noexcept_false_spec;
19592 }
19593 else
19594 spec = noexcept_false_spec;
19595 }
19596 else
19597 {
19598 /* This is an implicitly declared function, so NOEX is a list of
19599 other functions to evaluate and merge. */
19600 tree elt;
19601 spec = noexcept_true_spec;
19602 for (elt = noex; elt; elt = OVL_NEXT (elt))
19603 {
19604 tree fn = OVL_CURRENT (elt);
19605 tree subspec;
19606 maybe_instantiate_noexcept (fn);
19607 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
19608 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
19609 }
19610 }
19611
19612 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
19613
19614 FOR_EACH_CLONE (clone, fn)
19615 {
19616 if (TREE_TYPE (clone) == fntype)
19617 TREE_TYPE (clone) = TREE_TYPE (fn);
19618 else
19619 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
19620 }
19621 }
19622
19623 /* Produce the definition of D, a _DECL generated from a template. If
19624 DEFER_OK is nonzero, then we don't have to actually do the
19625 instantiation now; we just have to do it sometime. Normally it is
19626 an error if this is an explicit instantiation but D is undefined.
19627 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
19628 explicitly instantiated class template. */
19629
19630 tree
instantiate_decl(tree d,int defer_ok,bool expl_inst_class_mem_p)19631 instantiate_decl (tree d, int defer_ok,
19632 bool expl_inst_class_mem_p)
19633 {
19634 tree tmpl = DECL_TI_TEMPLATE (d);
19635 tree gen_args;
19636 tree args;
19637 tree td;
19638 tree code_pattern;
19639 tree spec;
19640 tree gen_tmpl;
19641 bool pattern_defined;
19642 location_t saved_loc = input_location;
19643 int saved_unevaluated_operand = cp_unevaluated_operand;
19644 int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
19645 bool external_p;
19646 tree fn_context;
19647 bool nested;
19648
19649 /* This function should only be used to instantiate templates for
19650 functions and static member variables. */
19651 gcc_assert (VAR_OR_FUNCTION_DECL_P (d));
19652
19653 /* Variables are never deferred; if instantiation is required, they
19654 are instantiated right away. That allows for better code in the
19655 case that an expression refers to the value of the variable --
19656 if the variable has a constant value the referring expression can
19657 take advantage of that fact. */
19658 if (VAR_P (d)
19659 || DECL_DECLARED_CONSTEXPR_P (d))
19660 defer_ok = 0;
19661
19662 /* Don't instantiate cloned functions. Instead, instantiate the
19663 functions they cloned. */
19664 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
19665 d = DECL_CLONED_FUNCTION (d);
19666
19667 if (DECL_TEMPLATE_INSTANTIATED (d)
19668 || (TREE_CODE (d) == FUNCTION_DECL
19669 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
19670 || DECL_TEMPLATE_SPECIALIZATION (d))
19671 /* D has already been instantiated or explicitly specialized, so
19672 there's nothing for us to do here.
19673
19674 It might seem reasonable to check whether or not D is an explicit
19675 instantiation, and, if so, stop here. But when an explicit
19676 instantiation is deferred until the end of the compilation,
19677 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
19678 the instantiation. */
19679 return d;
19680
19681 /* Check to see whether we know that this template will be
19682 instantiated in some other file, as with "extern template"
19683 extension. */
19684 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
19685
19686 /* In general, we do not instantiate such templates. */
19687 if (external_p && !always_instantiate_p (d))
19688 return d;
19689
19690 gen_tmpl = most_general_template (tmpl);
19691 gen_args = DECL_TI_ARGS (d);
19692
19693 if (tmpl != gen_tmpl)
19694 /* We should already have the extra args. */
19695 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
19696 == TMPL_ARGS_DEPTH (gen_args));
19697 /* And what's in the hash table should match D. */
19698 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
19699 || spec == NULL_TREE);
19700
19701 /* This needs to happen before any tsubsting. */
19702 if (! push_tinst_level (d))
19703 return d;
19704
19705 timevar_push (TV_TEMPLATE_INST);
19706
19707 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
19708 for the instantiation. */
19709 td = template_for_substitution (d);
19710 code_pattern = DECL_TEMPLATE_RESULT (td);
19711
19712 /* We should never be trying to instantiate a member of a class
19713 template or partial specialization. */
19714 gcc_assert (d != code_pattern);
19715
19716 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
19717 || DECL_TEMPLATE_SPECIALIZATION (td))
19718 /* In the case of a friend template whose definition is provided
19719 outside the class, we may have too many arguments. Drop the
19720 ones we don't need. The same is true for specializations. */
19721 args = get_innermost_template_args
19722 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
19723 else
19724 args = gen_args;
19725
19726 if (TREE_CODE (d) == FUNCTION_DECL)
19727 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
19728 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
19729 else
19730 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
19731
19732 /* We may be in the middle of deferred access check. Disable it now. */
19733 push_deferring_access_checks (dk_no_deferred);
19734
19735 /* Unless an explicit instantiation directive has already determined
19736 the linkage of D, remember that a definition is available for
19737 this entity. */
19738 if (pattern_defined
19739 && !DECL_INTERFACE_KNOWN (d)
19740 && !DECL_NOT_REALLY_EXTERN (d))
19741 mark_definable (d);
19742
19743 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
19744 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
19745 input_location = DECL_SOURCE_LOCATION (d);
19746
19747 /* If D is a member of an explicitly instantiated class template,
19748 and no definition is available, treat it like an implicit
19749 instantiation. */
19750 if (!pattern_defined && expl_inst_class_mem_p
19751 && DECL_EXPLICIT_INSTANTIATION (d))
19752 {
19753 /* Leave linkage flags alone on instantiations with anonymous
19754 visibility. */
19755 if (TREE_PUBLIC (d))
19756 {
19757 DECL_NOT_REALLY_EXTERN (d) = 0;
19758 DECL_INTERFACE_KNOWN (d) = 0;
19759 }
19760 SET_DECL_IMPLICIT_INSTANTIATION (d);
19761 }
19762
19763 if (TREE_CODE (d) == FUNCTION_DECL)
19764 maybe_instantiate_noexcept (d);
19765
19766 /* Defer all other templates, unless we have been explicitly
19767 forbidden from doing so. */
19768 if (/* If there is no definition, we cannot instantiate the
19769 template. */
19770 ! pattern_defined
19771 /* If it's OK to postpone instantiation, do so. */
19772 || defer_ok
19773 /* If this is a static data member that will be defined
19774 elsewhere, we don't want to instantiate the entire data
19775 member, but we do want to instantiate the initializer so that
19776 we can substitute that elsewhere. */
19777 || (external_p && VAR_P (d)))
19778 {
19779 /* The definition of the static data member is now required so
19780 we must substitute the initializer. */
19781 if (VAR_P (d)
19782 && !DECL_INITIAL (d)
19783 && DECL_INITIAL (code_pattern))
19784 {
19785 tree ns;
19786 tree init;
19787 bool const_init = false;
19788
19789 ns = decl_namespace_context (d);
19790 push_nested_namespace (ns);
19791 push_nested_class (DECL_CONTEXT (d));
19792 init = tsubst_expr (DECL_INITIAL (code_pattern),
19793 args,
19794 tf_warning_or_error, NULL_TREE,
19795 /*integral_constant_expression_p=*/false);
19796 /* Make sure the initializer is still constant, in case of
19797 circular dependency (template/instantiate6.C). */
19798 const_init
19799 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
19800 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
19801 /*asmspec_tree=*/NULL_TREE,
19802 LOOKUP_ONLYCONVERTING);
19803 pop_nested_class ();
19804 pop_nested_namespace (ns);
19805 }
19806
19807 /* We restore the source position here because it's used by
19808 add_pending_template. */
19809 input_location = saved_loc;
19810
19811 if (at_eof && !pattern_defined
19812 && DECL_EXPLICIT_INSTANTIATION (d)
19813 && DECL_NOT_REALLY_EXTERN (d))
19814 /* [temp.explicit]
19815
19816 The definition of a non-exported function template, a
19817 non-exported member function template, or a non-exported
19818 member function or static data member of a class template
19819 shall be present in every translation unit in which it is
19820 explicitly instantiated. */
19821 permerror (input_location, "explicit instantiation of %qD "
19822 "but no definition available", d);
19823
19824 /* If we're in unevaluated context, we just wanted to get the
19825 constant value; this isn't an odr use, so don't queue
19826 a full instantiation. */
19827 if (cp_unevaluated_operand != 0)
19828 goto out;
19829 /* ??? Historically, we have instantiated inline functions, even
19830 when marked as "extern template". */
19831 if (!(external_p && VAR_P (d)))
19832 add_pending_template (d);
19833 goto out;
19834 }
19835 /* Tell the repository that D is available in this translation unit
19836 -- and see if it is supposed to be instantiated here. */
19837 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
19838 {
19839 /* In a PCH file, despite the fact that the repository hasn't
19840 requested instantiation in the PCH it is still possible that
19841 an instantiation will be required in a file that includes the
19842 PCH. */
19843 if (pch_file)
19844 add_pending_template (d);
19845 /* Instantiate inline functions so that the inliner can do its
19846 job, even though we'll not be emitting a copy of this
19847 function. */
19848 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
19849 goto out;
19850 }
19851
19852 fn_context = decl_function_context (d);
19853 nested = (current_function_decl != NULL_TREE);
19854 if (!fn_context)
19855 push_to_top_level ();
19856 else
19857 {
19858 if (nested)
19859 push_function_context ();
19860 cp_unevaluated_operand = 0;
19861 c_inhibit_evaluation_warnings = 0;
19862 }
19863
19864 /* Mark D as instantiated so that recursive calls to
19865 instantiate_decl do not try to instantiate it again. */
19866 DECL_TEMPLATE_INSTANTIATED (d) = 1;
19867
19868 /* Regenerate the declaration in case the template has been modified
19869 by a subsequent redeclaration. */
19870 regenerate_decl_from_template (d, td);
19871
19872 /* We already set the file and line above. Reset them now in case
19873 they changed as a result of calling regenerate_decl_from_template. */
19874 input_location = DECL_SOURCE_LOCATION (d);
19875
19876 if (VAR_P (d))
19877 {
19878 tree init;
19879 bool const_init = false;
19880
19881 /* Clear out DECL_RTL; whatever was there before may not be right
19882 since we've reset the type of the declaration. */
19883 SET_DECL_RTL (d, NULL);
19884 DECL_IN_AGGR_P (d) = 0;
19885
19886 /* The initializer is placed in DECL_INITIAL by
19887 regenerate_decl_from_template so we don't need to
19888 push/pop_access_scope again here. Pull it out so that
19889 cp_finish_decl can process it. */
19890 init = DECL_INITIAL (d);
19891 DECL_INITIAL (d) = NULL_TREE;
19892 DECL_INITIALIZED_P (d) = 0;
19893
19894 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
19895 initializer. That function will defer actual emission until
19896 we have a chance to determine linkage. */
19897 DECL_EXTERNAL (d) = 0;
19898
19899 /* Enter the scope of D so that access-checking works correctly. */
19900 push_nested_class (DECL_CONTEXT (d));
19901 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
19902 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
19903 pop_nested_class ();
19904 }
19905 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
19906 synthesize_method (d);
19907 else if (TREE_CODE (d) == FUNCTION_DECL)
19908 {
19909 struct pointer_map_t *saved_local_specializations;
19910 tree subst_decl;
19911 tree tmpl_parm;
19912 tree spec_parm;
19913 tree block = NULL_TREE;
19914
19915 /* Save away the current list, in case we are instantiating one
19916 template from within the body of another. */
19917 saved_local_specializations = local_specializations;
19918
19919 /* Set up the list of local specializations. */
19920 local_specializations = pointer_map_create ();
19921
19922 /* Set up context. */
19923 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)
19924 && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL)
19925 block = push_stmt_list ();
19926 else
19927 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
19928
19929 /* Some typedefs referenced from within the template code need to be
19930 access checked at template instantiation time, i.e now. These
19931 types were added to the template at parsing time. Let's get those
19932 and perform the access checks then. */
19933 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (gen_tmpl),
19934 gen_args);
19935
19936 /* Create substitution entries for the parameters. */
19937 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
19938 tmpl_parm = DECL_ARGUMENTS (subst_decl);
19939 spec_parm = DECL_ARGUMENTS (d);
19940 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
19941 {
19942 register_local_specialization (spec_parm, tmpl_parm);
19943 spec_parm = skip_artificial_parms_for (d, spec_parm);
19944 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
19945 }
19946 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
19947 {
19948 if (!DECL_PACK_P (tmpl_parm))
19949 {
19950 register_local_specialization (spec_parm, tmpl_parm);
19951 spec_parm = DECL_CHAIN (spec_parm);
19952 }
19953 else
19954 {
19955 /* Register the (value) argument pack as a specialization of
19956 TMPL_PARM, then move on. */
19957 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
19958 register_local_specialization (argpack, tmpl_parm);
19959 }
19960 }
19961 gcc_assert (!spec_parm);
19962
19963 /* Substitute into the body of the function. */
19964 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern))
19965 tsubst_omp_udr (DECL_SAVED_TREE (code_pattern), args,
19966 tf_warning_or_error, tmpl);
19967 else
19968 {
19969 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
19970 tf_warning_or_error, tmpl,
19971 /*integral_constant_expression_p=*/false);
19972
19973 /* Set the current input_location to the end of the function
19974 so that finish_function knows where we are. */
19975 input_location
19976 = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
19977
19978 /* Remember if we saw an infinite loop in the template. */
19979 current_function_infinite_loop
19980 = DECL_STRUCT_FUNCTION (code_pattern)->language->infinite_loop;
19981 }
19982
19983 /* We don't need the local specializations any more. */
19984 pointer_map_destroy (local_specializations);
19985 local_specializations = saved_local_specializations;
19986
19987 /* Finish the function. */
19988 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)
19989 && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL)
19990 DECL_SAVED_TREE (d) = pop_stmt_list (block);
19991 else
19992 {
19993 d = finish_function (0);
19994 expand_or_defer_fn (d);
19995 }
19996
19997 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern))
19998 cp_check_omp_declare_reduction (d);
19999 }
20000
20001 /* We're not deferring instantiation any more. */
20002 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
20003
20004 if (!fn_context)
20005 pop_from_top_level ();
20006 else if (nested)
20007 pop_function_context ();
20008
20009 out:
20010 input_location = saved_loc;
20011 cp_unevaluated_operand = saved_unevaluated_operand;
20012 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
20013 pop_deferring_access_checks ();
20014 pop_tinst_level ();
20015
20016 timevar_pop (TV_TEMPLATE_INST);
20017
20018 return d;
20019 }
20020
20021 /* Run through the list of templates that we wish we could
20022 instantiate, and instantiate any we can. RETRIES is the
20023 number of times we retry pending template instantiation. */
20024
20025 void
instantiate_pending_templates(int retries)20026 instantiate_pending_templates (int retries)
20027 {
20028 int reconsider;
20029 location_t saved_loc = input_location;
20030
20031 /* Instantiating templates may trigger vtable generation. This in turn
20032 may require further template instantiations. We place a limit here
20033 to avoid infinite loop. */
20034 if (pending_templates && retries >= max_tinst_depth)
20035 {
20036 tree decl = pending_templates->tinst->decl;
20037
20038 error ("template instantiation depth exceeds maximum of %d"
20039 " instantiating %q+D, possibly from virtual table generation"
20040 " (use -ftemplate-depth= to increase the maximum)",
20041 max_tinst_depth, decl);
20042 if (TREE_CODE (decl) == FUNCTION_DECL)
20043 /* Pretend that we defined it. */
20044 DECL_INITIAL (decl) = error_mark_node;
20045 return;
20046 }
20047
20048 do
20049 {
20050 struct pending_template **t = &pending_templates;
20051 struct pending_template *last = NULL;
20052 reconsider = 0;
20053 while (*t)
20054 {
20055 tree instantiation = reopen_tinst_level ((*t)->tinst);
20056 bool complete = false;
20057
20058 if (TYPE_P (instantiation))
20059 {
20060 tree fn;
20061
20062 if (!COMPLETE_TYPE_P (instantiation))
20063 {
20064 instantiate_class_template (instantiation);
20065 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
20066 for (fn = TYPE_METHODS (instantiation);
20067 fn;
20068 fn = TREE_CHAIN (fn))
20069 if (! DECL_ARTIFICIAL (fn))
20070 instantiate_decl (fn,
20071 /*defer_ok=*/0,
20072 /*expl_inst_class_mem_p=*/false);
20073 if (COMPLETE_TYPE_P (instantiation))
20074 reconsider = 1;
20075 }
20076
20077 complete = COMPLETE_TYPE_P (instantiation);
20078 }
20079 else
20080 {
20081 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
20082 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
20083 {
20084 instantiation
20085 = instantiate_decl (instantiation,
20086 /*defer_ok=*/0,
20087 /*expl_inst_class_mem_p=*/false);
20088 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
20089 reconsider = 1;
20090 }
20091
20092 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
20093 || DECL_TEMPLATE_INSTANTIATED (instantiation));
20094 }
20095
20096 if (complete)
20097 /* If INSTANTIATION has been instantiated, then we don't
20098 need to consider it again in the future. */
20099 *t = (*t)->next;
20100 else
20101 {
20102 last = *t;
20103 t = &(*t)->next;
20104 }
20105 tinst_depth = 0;
20106 current_tinst_level = NULL;
20107 }
20108 last_pending_template = last;
20109 }
20110 while (reconsider);
20111
20112 input_location = saved_loc;
20113 }
20114
20115 /* Substitute ARGVEC into T, which is a list of initializers for
20116 either base class or a non-static data member. The TREE_PURPOSEs
20117 are DECLs, and the TREE_VALUEs are the initializer values. Used by
20118 instantiate_decl. */
20119
20120 static tree
tsubst_initializer_list(tree t,tree argvec)20121 tsubst_initializer_list (tree t, tree argvec)
20122 {
20123 tree inits = NULL_TREE;
20124
20125 for (; t; t = TREE_CHAIN (t))
20126 {
20127 tree decl;
20128 tree init;
20129 tree expanded_bases = NULL_TREE;
20130 tree expanded_arguments = NULL_TREE;
20131 int i, len = 1;
20132
20133 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
20134 {
20135 tree expr;
20136 tree arg;
20137
20138 /* Expand the base class expansion type into separate base
20139 classes. */
20140 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
20141 tf_warning_or_error,
20142 NULL_TREE);
20143 if (expanded_bases == error_mark_node)
20144 continue;
20145
20146 /* We'll be building separate TREE_LISTs of arguments for
20147 each base. */
20148 len = TREE_VEC_LENGTH (expanded_bases);
20149 expanded_arguments = make_tree_vec (len);
20150 for (i = 0; i < len; i++)
20151 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
20152
20153 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
20154 expand each argument in the TREE_VALUE of t. */
20155 expr = make_node (EXPR_PACK_EXPANSION);
20156 PACK_EXPANSION_LOCAL_P (expr) = true;
20157 PACK_EXPANSION_PARAMETER_PACKS (expr) =
20158 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
20159
20160 if (TREE_VALUE (t) == void_type_node)
20161 /* VOID_TYPE_NODE is used to indicate
20162 value-initialization. */
20163 {
20164 for (i = 0; i < len; i++)
20165 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
20166 }
20167 else
20168 {
20169 /* Substitute parameter packs into each argument in the
20170 TREE_LIST. */
20171 in_base_initializer = 1;
20172 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
20173 {
20174 tree expanded_exprs;
20175
20176 /* Expand the argument. */
20177 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
20178 expanded_exprs
20179 = tsubst_pack_expansion (expr, argvec,
20180 tf_warning_or_error,
20181 NULL_TREE);
20182 if (expanded_exprs == error_mark_node)
20183 continue;
20184
20185 /* Prepend each of the expanded expressions to the
20186 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
20187 for (i = 0; i < len; i++)
20188 {
20189 TREE_VEC_ELT (expanded_arguments, i) =
20190 tree_cons (NULL_TREE,
20191 TREE_VEC_ELT (expanded_exprs, i),
20192 TREE_VEC_ELT (expanded_arguments, i));
20193 }
20194 }
20195 in_base_initializer = 0;
20196
20197 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
20198 since we built them backwards. */
20199 for (i = 0; i < len; i++)
20200 {
20201 TREE_VEC_ELT (expanded_arguments, i) =
20202 nreverse (TREE_VEC_ELT (expanded_arguments, i));
20203 }
20204 }
20205 }
20206
20207 for (i = 0; i < len; ++i)
20208 {
20209 if (expanded_bases)
20210 {
20211 decl = TREE_VEC_ELT (expanded_bases, i);
20212 decl = expand_member_init (decl);
20213 init = TREE_VEC_ELT (expanded_arguments, i);
20214 }
20215 else
20216 {
20217 tree tmp;
20218 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
20219 tf_warning_or_error, NULL_TREE);
20220
20221 decl = expand_member_init (decl);
20222 if (decl && !DECL_P (decl))
20223 in_base_initializer = 1;
20224
20225 init = TREE_VALUE (t);
20226 tmp = init;
20227 if (init != void_type_node)
20228 init = tsubst_expr (init, argvec,
20229 tf_warning_or_error, NULL_TREE,
20230 /*integral_constant_expression_p=*/false);
20231 if (init == NULL_TREE && tmp != NULL_TREE)
20232 /* If we had an initializer but it instantiated to nothing,
20233 value-initialize the object. This will only occur when
20234 the initializer was a pack expansion where the parameter
20235 packs used in that expansion were of length zero. */
20236 init = void_type_node;
20237 in_base_initializer = 0;
20238 }
20239
20240 if (decl)
20241 {
20242 init = build_tree_list (decl, init);
20243 TREE_CHAIN (init) = inits;
20244 inits = init;
20245 }
20246 }
20247 }
20248 return inits;
20249 }
20250
20251 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
20252
20253 static void
set_current_access_from_decl(tree decl)20254 set_current_access_from_decl (tree decl)
20255 {
20256 if (TREE_PRIVATE (decl))
20257 current_access_specifier = access_private_node;
20258 else if (TREE_PROTECTED (decl))
20259 current_access_specifier = access_protected_node;
20260 else
20261 current_access_specifier = access_public_node;
20262 }
20263
20264 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
20265 is the instantiation (which should have been created with
20266 start_enum) and ARGS are the template arguments to use. */
20267
20268 static void
tsubst_enum(tree tag,tree newtag,tree args)20269 tsubst_enum (tree tag, tree newtag, tree args)
20270 {
20271 tree e;
20272
20273 if (SCOPED_ENUM_P (newtag))
20274 begin_scope (sk_scoped_enum, newtag);
20275
20276 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
20277 {
20278 tree value;
20279 tree decl;
20280
20281 decl = TREE_VALUE (e);
20282 /* Note that in a template enum, the TREE_VALUE is the
20283 CONST_DECL, not the corresponding INTEGER_CST. */
20284 value = tsubst_expr (DECL_INITIAL (decl),
20285 args, tf_warning_or_error, NULL_TREE,
20286 /*integral_constant_expression_p=*/true);
20287
20288 /* Give this enumeration constant the correct access. */
20289 set_current_access_from_decl (decl);
20290
20291 /* Actually build the enumerator itself. */
20292 build_enumerator
20293 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
20294 }
20295
20296 if (SCOPED_ENUM_P (newtag))
20297 finish_scope ();
20298
20299 finish_enum_value_list (newtag);
20300 finish_enum (newtag);
20301
20302 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
20303 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
20304 }
20305
20306 /* DECL is a FUNCTION_DECL that is a template specialization. Return
20307 its type -- but without substituting the innermost set of template
20308 arguments. So, innermost set of template parameters will appear in
20309 the type. */
20310
20311 tree
get_mostly_instantiated_function_type(tree decl)20312 get_mostly_instantiated_function_type (tree decl)
20313 {
20314 tree fn_type;
20315 tree tmpl;
20316 tree targs;
20317 tree tparms;
20318 int parm_depth;
20319
20320 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
20321 targs = DECL_TI_ARGS (decl);
20322 tparms = DECL_TEMPLATE_PARMS (tmpl);
20323 parm_depth = TMPL_PARMS_DEPTH (tparms);
20324
20325 /* There should be as many levels of arguments as there are levels
20326 of parameters. */
20327 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
20328
20329 fn_type = TREE_TYPE (tmpl);
20330
20331 if (parm_depth == 1)
20332 /* No substitution is necessary. */
20333 ;
20334 else
20335 {
20336 int i;
20337 tree partial_args;
20338
20339 /* Replace the innermost level of the TARGS with NULL_TREEs to
20340 let tsubst know not to substitute for those parameters. */
20341 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
20342 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
20343 SET_TMPL_ARGS_LEVEL (partial_args, i,
20344 TMPL_ARGS_LEVEL (targs, i));
20345 SET_TMPL_ARGS_LEVEL (partial_args,
20346 TMPL_ARGS_DEPTH (targs),
20347 make_tree_vec (DECL_NTPARMS (tmpl)));
20348
20349 /* Make sure that we can see identifiers, and compute access
20350 correctly. */
20351 push_access_scope (decl);
20352
20353 ++processing_template_decl;
20354 /* Now, do the (partial) substitution to figure out the
20355 appropriate function type. */
20356 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
20357 --processing_template_decl;
20358
20359 /* Substitute into the template parameters to obtain the real
20360 innermost set of parameters. This step is important if the
20361 innermost set of template parameters contains value
20362 parameters whose types depend on outer template parameters. */
20363 TREE_VEC_LENGTH (partial_args)--;
20364 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
20365
20366 pop_access_scope (decl);
20367 }
20368
20369 return fn_type;
20370 }
20371
20372 /* Return truthvalue if we're processing a template different from
20373 the last one involved in diagnostics. */
20374 int
problematic_instantiation_changed(void)20375 problematic_instantiation_changed (void)
20376 {
20377 return current_tinst_level != last_error_tinst_level;
20378 }
20379
20380 /* Remember current template involved in diagnostics. */
20381 void
record_last_problematic_instantiation(void)20382 record_last_problematic_instantiation (void)
20383 {
20384 last_error_tinst_level = current_tinst_level;
20385 }
20386
20387 struct tinst_level *
current_instantiation(void)20388 current_instantiation (void)
20389 {
20390 return current_tinst_level;
20391 }
20392
20393 /* [temp.param] Check that template non-type parm TYPE is of an allowable
20394 type. Return zero for ok, nonzero for disallowed. Issue error and
20395 warning messages under control of COMPLAIN. */
20396
20397 static int
invalid_nontype_parm_type_p(tree type,tsubst_flags_t complain)20398 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
20399 {
20400 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
20401 return 0;
20402 else if (POINTER_TYPE_P (type))
20403 return 0;
20404 else if (TYPE_PTRMEM_P (type))
20405 return 0;
20406 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
20407 return 0;
20408 else if (TREE_CODE (type) == TYPENAME_TYPE)
20409 return 0;
20410 else if (TREE_CODE (type) == DECLTYPE_TYPE)
20411 return 0;
20412 else if (TREE_CODE (type) == NULLPTR_TYPE)
20413 return 0;
20414
20415 if (complain & tf_error)
20416 {
20417 if (type == error_mark_node)
20418 inform (input_location, "invalid template non-type parameter");
20419 else
20420 error ("%q#T is not a valid type for a template non-type parameter",
20421 type);
20422 }
20423 return 1;
20424 }
20425
20426 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
20427 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
20428
20429 static bool
dependent_type_p_r(tree type)20430 dependent_type_p_r (tree type)
20431 {
20432 tree scope;
20433
20434 /* [temp.dep.type]
20435
20436 A type is dependent if it is:
20437
20438 -- a template parameter. Template template parameters are types
20439 for us (since TYPE_P holds true for them) so we handle
20440 them here. */
20441 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20442 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
20443 return true;
20444 /* -- a qualified-id with a nested-name-specifier which contains a
20445 class-name that names a dependent type or whose unqualified-id
20446 names a dependent type. */
20447 if (TREE_CODE (type) == TYPENAME_TYPE)
20448 return true;
20449 /* -- a cv-qualified type where the cv-unqualified type is
20450 dependent. */
20451 type = TYPE_MAIN_VARIANT (type);
20452 /* -- a compound type constructed from any dependent type. */
20453 if (TYPE_PTRMEM_P (type))
20454 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
20455 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
20456 (type)));
20457 else if (TYPE_PTR_P (type)
20458 || TREE_CODE (type) == REFERENCE_TYPE)
20459 return dependent_type_p (TREE_TYPE (type));
20460 else if (TREE_CODE (type) == FUNCTION_TYPE
20461 || TREE_CODE (type) == METHOD_TYPE)
20462 {
20463 tree arg_type;
20464
20465 if (dependent_type_p (TREE_TYPE (type)))
20466 return true;
20467 for (arg_type = TYPE_ARG_TYPES (type);
20468 arg_type;
20469 arg_type = TREE_CHAIN (arg_type))
20470 if (dependent_type_p (TREE_VALUE (arg_type)))
20471 return true;
20472 return false;
20473 }
20474 /* -- an array type constructed from any dependent type or whose
20475 size is specified by a constant expression that is
20476 value-dependent.
20477
20478 We checked for type- and value-dependence of the bounds in
20479 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
20480 if (TREE_CODE (type) == ARRAY_TYPE)
20481 {
20482 if (TYPE_DOMAIN (type)
20483 && dependent_type_p (TYPE_DOMAIN (type)))
20484 return true;
20485 return dependent_type_p (TREE_TYPE (type));
20486 }
20487
20488 /* -- a template-id in which either the template name is a template
20489 parameter ... */
20490 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
20491 return true;
20492 /* ... or any of the template arguments is a dependent type or
20493 an expression that is type-dependent or value-dependent. */
20494 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
20495 && (any_dependent_template_arguments_p
20496 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
20497 return true;
20498
20499 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
20500 dependent; if the argument of the `typeof' expression is not
20501 type-dependent, then it should already been have resolved. */
20502 if (TREE_CODE (type) == TYPEOF_TYPE
20503 || TREE_CODE (type) == DECLTYPE_TYPE
20504 || TREE_CODE (type) == UNDERLYING_TYPE)
20505 return true;
20506
20507 /* A template argument pack is dependent if any of its packed
20508 arguments are. */
20509 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
20510 {
20511 tree args = ARGUMENT_PACK_ARGS (type);
20512 int i, len = TREE_VEC_LENGTH (args);
20513 for (i = 0; i < len; ++i)
20514 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
20515 return true;
20516 }
20517
20518 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
20519 be template parameters. */
20520 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
20521 return true;
20522
20523 /* The standard does not specifically mention types that are local
20524 to template functions or local classes, but they should be
20525 considered dependent too. For example:
20526
20527 template <int I> void f() {
20528 enum E { a = I };
20529 S<sizeof (E)> s;
20530 }
20531
20532 The size of `E' cannot be known until the value of `I' has been
20533 determined. Therefore, `E' must be considered dependent. */
20534 scope = TYPE_CONTEXT (type);
20535 if (scope && TYPE_P (scope))
20536 return dependent_type_p (scope);
20537 /* Don't use type_dependent_expression_p here, as it can lead
20538 to infinite recursion trying to determine whether a lambda
20539 nested in a lambda is dependent (c++/47687). */
20540 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
20541 && DECL_LANG_SPECIFIC (scope)
20542 && DECL_TEMPLATE_INFO (scope)
20543 && (any_dependent_template_arguments_p
20544 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
20545 return true;
20546
20547 /* Other types are non-dependent. */
20548 return false;
20549 }
20550
20551 /* Returns TRUE if TYPE is dependent, in the sense of
20552 [temp.dep.type]. Note that a NULL type is considered dependent. */
20553
20554 bool
dependent_type_p(tree type)20555 dependent_type_p (tree type)
20556 {
20557 /* If there are no template parameters in scope, then there can't be
20558 any dependent types. */
20559 if (!processing_template_decl)
20560 {
20561 /* If we are not processing a template, then nobody should be
20562 providing us with a dependent type. */
20563 gcc_assert (type);
20564 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
20565 return false;
20566 }
20567
20568 /* If the type is NULL, we have not computed a type for the entity
20569 in question; in that case, the type is dependent. */
20570 if (!type)
20571 return true;
20572
20573 /* Erroneous types can be considered non-dependent. */
20574 if (type == error_mark_node)
20575 return false;
20576
20577 /* If we have not already computed the appropriate value for TYPE,
20578 do so now. */
20579 if (!TYPE_DEPENDENT_P_VALID (type))
20580 {
20581 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
20582 TYPE_DEPENDENT_P_VALID (type) = 1;
20583 }
20584
20585 return TYPE_DEPENDENT_P (type);
20586 }
20587
20588 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
20589 lookup. In other words, a dependent type that is not the current
20590 instantiation. */
20591
20592 bool
dependent_scope_p(tree scope)20593 dependent_scope_p (tree scope)
20594 {
20595 return (scope && TYPE_P (scope) && dependent_type_p (scope)
20596 && !currently_open_class (scope));
20597 }
20598
20599 /* T is a SCOPE_REF; return whether we need to consider it
20600 instantiation-dependent so that we can check access at instantiation
20601 time even though we know which member it resolves to. */
20602
20603 static bool
instantiation_dependent_scope_ref_p(tree t)20604 instantiation_dependent_scope_ref_p (tree t)
20605 {
20606 if (DECL_P (TREE_OPERAND (t, 1))
20607 && CLASS_TYPE_P (TREE_OPERAND (t, 0))
20608 && accessible_in_template_p (TREE_OPERAND (t, 0),
20609 TREE_OPERAND (t, 1)))
20610 return false;
20611 else
20612 return true;
20613 }
20614
20615 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
20616 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
20617 expression. */
20618
20619 /* Note that this predicate is not appropriate for general expressions;
20620 only constant expressions (that satisfy potential_constant_expression)
20621 can be tested for value dependence. */
20622
20623 bool
value_dependent_expression_p(tree expression)20624 value_dependent_expression_p (tree expression)
20625 {
20626 if (!processing_template_decl)
20627 return false;
20628
20629 /* A name declared with a dependent type. */
20630 if (DECL_P (expression) && type_dependent_expression_p (expression))
20631 return true;
20632
20633 switch (TREE_CODE (expression))
20634 {
20635 case IDENTIFIER_NODE:
20636 /* A name that has not been looked up -- must be dependent. */
20637 return true;
20638
20639 case TEMPLATE_PARM_INDEX:
20640 /* A non-type template parm. */
20641 return true;
20642
20643 case CONST_DECL:
20644 /* A non-type template parm. */
20645 if (DECL_TEMPLATE_PARM_P (expression))
20646 return true;
20647 return value_dependent_expression_p (DECL_INITIAL (expression));
20648
20649 case VAR_DECL:
20650 /* A constant with literal type and is initialized
20651 with an expression that is value-dependent.
20652
20653 Note that a non-dependent parenthesized initializer will have
20654 already been replaced with its constant value, so if we see
20655 a TREE_LIST it must be dependent. */
20656 if (DECL_INITIAL (expression)
20657 && decl_constant_var_p (expression)
20658 && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST
20659 || value_dependent_expression_p (DECL_INITIAL (expression))))
20660 return true;
20661 return false;
20662
20663 case DYNAMIC_CAST_EXPR:
20664 case STATIC_CAST_EXPR:
20665 case CONST_CAST_EXPR:
20666 case REINTERPRET_CAST_EXPR:
20667 case CAST_EXPR:
20668 /* These expressions are value-dependent if the type to which
20669 the cast occurs is dependent or the expression being casted
20670 is value-dependent. */
20671 {
20672 tree type = TREE_TYPE (expression);
20673
20674 if (dependent_type_p (type))
20675 return true;
20676
20677 /* A functional cast has a list of operands. */
20678 expression = TREE_OPERAND (expression, 0);
20679 if (!expression)
20680 {
20681 /* If there are no operands, it must be an expression such
20682 as "int()". This should not happen for aggregate types
20683 because it would form non-constant expressions. */
20684 gcc_assert (cxx_dialect >= cxx11
20685 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
20686
20687 return false;
20688 }
20689
20690 if (TREE_CODE (expression) == TREE_LIST)
20691 return any_value_dependent_elements_p (expression);
20692
20693 return value_dependent_expression_p (expression);
20694 }
20695
20696 case SIZEOF_EXPR:
20697 if (SIZEOF_EXPR_TYPE_P (expression))
20698 return dependent_type_p (TREE_TYPE (TREE_OPERAND (expression, 0)));
20699 /* FALLTHRU */
20700 case ALIGNOF_EXPR:
20701 case TYPEID_EXPR:
20702 /* A `sizeof' expression is value-dependent if the operand is
20703 type-dependent or is a pack expansion. */
20704 expression = TREE_OPERAND (expression, 0);
20705 if (PACK_EXPANSION_P (expression))
20706 return true;
20707 else if (TYPE_P (expression))
20708 return dependent_type_p (expression);
20709 return instantiation_dependent_expression_p (expression);
20710
20711 case AT_ENCODE_EXPR:
20712 /* An 'encode' expression is value-dependent if the operand is
20713 type-dependent. */
20714 expression = TREE_OPERAND (expression, 0);
20715 return dependent_type_p (expression);
20716
20717 case NOEXCEPT_EXPR:
20718 expression = TREE_OPERAND (expression, 0);
20719 return instantiation_dependent_expression_p (expression);
20720
20721 case SCOPE_REF:
20722 /* All instantiation-dependent expressions should also be considered
20723 value-dependent. */
20724 return instantiation_dependent_scope_ref_p (expression);
20725
20726 case COMPONENT_REF:
20727 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
20728 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
20729
20730 case NONTYPE_ARGUMENT_PACK:
20731 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
20732 is value-dependent. */
20733 {
20734 tree values = ARGUMENT_PACK_ARGS (expression);
20735 int i, len = TREE_VEC_LENGTH (values);
20736
20737 for (i = 0; i < len; ++i)
20738 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
20739 return true;
20740
20741 return false;
20742 }
20743
20744 case TRAIT_EXPR:
20745 {
20746 tree type2 = TRAIT_EXPR_TYPE2 (expression);
20747 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
20748 || (type2 ? dependent_type_p (type2) : false));
20749 }
20750
20751 case MODOP_EXPR:
20752 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
20753 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
20754
20755 case ARRAY_REF:
20756 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
20757 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
20758
20759 case ADDR_EXPR:
20760 {
20761 tree op = TREE_OPERAND (expression, 0);
20762 return (value_dependent_expression_p (op)
20763 || has_value_dependent_address (op));
20764 }
20765
20766 case CALL_EXPR:
20767 {
20768 tree fn = get_callee_fndecl (expression);
20769 int i, nargs;
20770 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
20771 return true;
20772 nargs = call_expr_nargs (expression);
20773 for (i = 0; i < nargs; ++i)
20774 {
20775 tree op = CALL_EXPR_ARG (expression, i);
20776 /* In a call to a constexpr member function, look through the
20777 implicit ADDR_EXPR on the object argument so that it doesn't
20778 cause the call to be considered value-dependent. We also
20779 look through it in potential_constant_expression. */
20780 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
20781 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
20782 && TREE_CODE (op) == ADDR_EXPR)
20783 op = TREE_OPERAND (op, 0);
20784 if (value_dependent_expression_p (op))
20785 return true;
20786 }
20787 return false;
20788 }
20789
20790 case TEMPLATE_ID_EXPR:
20791 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
20792 type-dependent. */
20793 return type_dependent_expression_p (expression);
20794
20795 case CONSTRUCTOR:
20796 {
20797 unsigned ix;
20798 tree val;
20799 if (dependent_type_p (TREE_TYPE (expression)))
20800 return true;
20801 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
20802 if (value_dependent_expression_p (val))
20803 return true;
20804 return false;
20805 }
20806
20807 case STMT_EXPR:
20808 /* Treat a GNU statement expression as dependent to avoid crashing
20809 under fold_non_dependent_expr; it can't be constant. */
20810 return true;
20811
20812 default:
20813 /* A constant expression is value-dependent if any subexpression is
20814 value-dependent. */
20815 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
20816 {
20817 case tcc_reference:
20818 case tcc_unary:
20819 case tcc_comparison:
20820 case tcc_binary:
20821 case tcc_expression:
20822 case tcc_vl_exp:
20823 {
20824 int i, len = cp_tree_operand_length (expression);
20825
20826 for (i = 0; i < len; i++)
20827 {
20828 tree t = TREE_OPERAND (expression, i);
20829
20830 /* In some cases, some of the operands may be missing.l
20831 (For example, in the case of PREDECREMENT_EXPR, the
20832 amount to increment by may be missing.) That doesn't
20833 make the expression dependent. */
20834 if (t && value_dependent_expression_p (t))
20835 return true;
20836 }
20837 }
20838 break;
20839 default:
20840 break;
20841 }
20842 break;
20843 }
20844
20845 /* The expression is not value-dependent. */
20846 return false;
20847 }
20848
20849 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
20850 [temp.dep.expr]. Note that an expression with no type is
20851 considered dependent. Other parts of the compiler arrange for an
20852 expression with type-dependent subexpressions to have no type, so
20853 this function doesn't have to be fully recursive. */
20854
20855 bool
type_dependent_expression_p(tree expression)20856 type_dependent_expression_p (tree expression)
20857 {
20858 if (!processing_template_decl)
20859 return false;
20860
20861 if (expression == NULL_TREE || expression == error_mark_node)
20862 return false;
20863
20864 /* An unresolved name is always dependent. */
20865 if (identifier_p (expression) || TREE_CODE (expression) == USING_DECL)
20866 return true;
20867
20868 /* Some expression forms are never type-dependent. */
20869 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
20870 || TREE_CODE (expression) == SIZEOF_EXPR
20871 || TREE_CODE (expression) == ALIGNOF_EXPR
20872 || TREE_CODE (expression) == AT_ENCODE_EXPR
20873 || TREE_CODE (expression) == NOEXCEPT_EXPR
20874 || TREE_CODE (expression) == TRAIT_EXPR
20875 || TREE_CODE (expression) == TYPEID_EXPR
20876 || TREE_CODE (expression) == DELETE_EXPR
20877 || TREE_CODE (expression) == VEC_DELETE_EXPR
20878 || TREE_CODE (expression) == THROW_EXPR)
20879 return false;
20880
20881 /* The types of these expressions depends only on the type to which
20882 the cast occurs. */
20883 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
20884 || TREE_CODE (expression) == STATIC_CAST_EXPR
20885 || TREE_CODE (expression) == CONST_CAST_EXPR
20886 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
20887 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
20888 || TREE_CODE (expression) == CAST_EXPR)
20889 return dependent_type_p (TREE_TYPE (expression));
20890
20891 /* The types of these expressions depends only on the type created
20892 by the expression. */
20893 if (TREE_CODE (expression) == NEW_EXPR
20894 || TREE_CODE (expression) == VEC_NEW_EXPR)
20895 {
20896 /* For NEW_EXPR tree nodes created inside a template, either
20897 the object type itself or a TREE_LIST may appear as the
20898 operand 1. */
20899 tree type = TREE_OPERAND (expression, 1);
20900 if (TREE_CODE (type) == TREE_LIST)
20901 /* This is an array type. We need to check array dimensions
20902 as well. */
20903 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
20904 || value_dependent_expression_p
20905 (TREE_OPERAND (TREE_VALUE (type), 1));
20906 else
20907 return dependent_type_p (type);
20908 }
20909
20910 if (TREE_CODE (expression) == SCOPE_REF)
20911 {
20912 tree scope = TREE_OPERAND (expression, 0);
20913 tree name = TREE_OPERAND (expression, 1);
20914
20915 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
20916 contains an identifier associated by name lookup with one or more
20917 declarations declared with a dependent type, or...a
20918 nested-name-specifier or qualified-id that names a member of an
20919 unknown specialization. */
20920 return (type_dependent_expression_p (name)
20921 || dependent_scope_p (scope));
20922 }
20923
20924 if (TREE_CODE (expression) == FUNCTION_DECL
20925 && DECL_LANG_SPECIFIC (expression)
20926 && DECL_TEMPLATE_INFO (expression)
20927 && (any_dependent_template_arguments_p
20928 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
20929 return true;
20930
20931 if (TREE_CODE (expression) == TEMPLATE_DECL
20932 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
20933 return false;
20934
20935 if (TREE_CODE (expression) == STMT_EXPR)
20936 expression = stmt_expr_value_expr (expression);
20937
20938 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
20939 {
20940 tree elt;
20941 unsigned i;
20942
20943 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
20944 {
20945 if (type_dependent_expression_p (elt))
20946 return true;
20947 }
20948 return false;
20949 }
20950
20951 /* A static data member of the current instantiation with incomplete
20952 array type is type-dependent, as the definition and specializations
20953 can have different bounds. */
20954 if (VAR_P (expression)
20955 && DECL_CLASS_SCOPE_P (expression)
20956 && dependent_type_p (DECL_CONTEXT (expression))
20957 && VAR_HAD_UNKNOWN_BOUND (expression))
20958 return true;
20959
20960 /* An array of unknown bound depending on a variadic parameter, eg:
20961
20962 template<typename... Args>
20963 void foo (Args... args)
20964 {
20965 int arr[] = { args... };
20966 }
20967
20968 template<int... vals>
20969 void bar ()
20970 {
20971 int arr[] = { vals... };
20972 }
20973
20974 If the array has no length and has an initializer, it must be that
20975 we couldn't determine its length in cp_complete_array_type because
20976 it is dependent. */
20977 if (VAR_P (expression)
20978 && TREE_CODE (TREE_TYPE (expression)) == ARRAY_TYPE
20979 && !TYPE_DOMAIN (TREE_TYPE (expression))
20980 && DECL_INITIAL (expression))
20981 return true;
20982
20983 if (TREE_TYPE (expression) == unknown_type_node)
20984 {
20985 if (TREE_CODE (expression) == ADDR_EXPR)
20986 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
20987 if (TREE_CODE (expression) == COMPONENT_REF
20988 || TREE_CODE (expression) == OFFSET_REF)
20989 {
20990 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
20991 return true;
20992 expression = TREE_OPERAND (expression, 1);
20993 if (identifier_p (expression))
20994 return false;
20995 }
20996 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
20997 if (TREE_CODE (expression) == SCOPE_REF)
20998 return false;
20999
21000 /* Always dependent, on the number of arguments if nothing else. */
21001 if (TREE_CODE (expression) == EXPR_PACK_EXPANSION)
21002 return true;
21003
21004 if (BASELINK_P (expression))
21005 {
21006 if (BASELINK_OPTYPE (expression)
21007 && dependent_type_p (BASELINK_OPTYPE (expression)))
21008 return true;
21009 expression = BASELINK_FUNCTIONS (expression);
21010 }
21011
21012 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
21013 {
21014 if (any_dependent_template_arguments_p
21015 (TREE_OPERAND (expression, 1)))
21016 return true;
21017 expression = TREE_OPERAND (expression, 0);
21018 }
21019 gcc_assert (TREE_CODE (expression) == OVERLOAD
21020 || TREE_CODE (expression) == FUNCTION_DECL);
21021
21022 while (expression)
21023 {
21024 if (type_dependent_expression_p (OVL_CURRENT (expression)))
21025 return true;
21026 expression = OVL_NEXT (expression);
21027 }
21028 return false;
21029 }
21030
21031 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
21032
21033 return (dependent_type_p (TREE_TYPE (expression)));
21034 }
21035
21036 /* walk_tree callback function for instantiation_dependent_expression_p,
21037 below. Returns non-zero if a dependent subexpression is found. */
21038
21039 static tree
instantiation_dependent_r(tree * tp,int * walk_subtrees,void *)21040 instantiation_dependent_r (tree *tp, int *walk_subtrees,
21041 void * /*data*/)
21042 {
21043 if (TYPE_P (*tp))
21044 {
21045 /* We don't have to worry about decltype currently because decltype
21046 of an instantiation-dependent expr is a dependent type. This
21047 might change depending on the resolution of DR 1172. */
21048 *walk_subtrees = false;
21049 return NULL_TREE;
21050 }
21051 enum tree_code code = TREE_CODE (*tp);
21052 switch (code)
21053 {
21054 /* Don't treat an argument list as dependent just because it has no
21055 TREE_TYPE. */
21056 case TREE_LIST:
21057 case TREE_VEC:
21058 return NULL_TREE;
21059
21060 case VAR_DECL:
21061 case CONST_DECL:
21062 /* A constant with a dependent initializer is dependent. */
21063 if (value_dependent_expression_p (*tp))
21064 return *tp;
21065 break;
21066
21067 case TEMPLATE_PARM_INDEX:
21068 return *tp;
21069
21070 /* Handle expressions with type operands. */
21071 case SIZEOF_EXPR:
21072 case ALIGNOF_EXPR:
21073 case TYPEID_EXPR:
21074 case AT_ENCODE_EXPR:
21075 {
21076 tree op = TREE_OPERAND (*tp, 0);
21077 if (code == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (*tp))
21078 op = TREE_TYPE (op);
21079 if (TYPE_P (op))
21080 {
21081 if (dependent_type_p (op))
21082 return *tp;
21083 else
21084 {
21085 *walk_subtrees = false;
21086 return NULL_TREE;
21087 }
21088 }
21089 break;
21090 }
21091
21092 case TRAIT_EXPR:
21093 if (dependent_type_p (TRAIT_EXPR_TYPE1 (*tp))
21094 || (TRAIT_EXPR_TYPE2 (*tp)
21095 && dependent_type_p (TRAIT_EXPR_TYPE2 (*tp))))
21096 return *tp;
21097 *walk_subtrees = false;
21098 return NULL_TREE;
21099
21100 case COMPONENT_REF:
21101 if (identifier_p (TREE_OPERAND (*tp, 1)))
21102 /* In a template, finish_class_member_access_expr creates a
21103 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
21104 type-dependent, so that we can check access control at
21105 instantiation time (PR 42277). See also Core issue 1273. */
21106 return *tp;
21107 break;
21108
21109 case SCOPE_REF:
21110 if (instantiation_dependent_scope_ref_p (*tp))
21111 return *tp;
21112 else
21113 break;
21114
21115 /* Treat statement-expressions as dependent. */
21116 case BIND_EXPR:
21117 return *tp;
21118
21119 default:
21120 break;
21121 }
21122
21123 if (type_dependent_expression_p (*tp))
21124 return *tp;
21125 else
21126 return NULL_TREE;
21127 }
21128
21129 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
21130 sense defined by the ABI:
21131
21132 "An expression is instantiation-dependent if it is type-dependent
21133 or value-dependent, or it has a subexpression that is type-dependent
21134 or value-dependent." */
21135
21136 bool
instantiation_dependent_expression_p(tree expression)21137 instantiation_dependent_expression_p (tree expression)
21138 {
21139 tree result;
21140
21141 if (!processing_template_decl)
21142 return false;
21143
21144 if (expression == error_mark_node)
21145 return false;
21146
21147 result = cp_walk_tree_without_duplicates (&expression,
21148 instantiation_dependent_r, NULL);
21149 return result != NULL_TREE;
21150 }
21151
21152 /* Like type_dependent_expression_p, but it also works while not processing
21153 a template definition, i.e. during substitution or mangling. */
21154
21155 bool
type_dependent_expression_p_push(tree expr)21156 type_dependent_expression_p_push (tree expr)
21157 {
21158 bool b;
21159 ++processing_template_decl;
21160 b = type_dependent_expression_p (expr);
21161 --processing_template_decl;
21162 return b;
21163 }
21164
21165 /* Returns TRUE if ARGS contains a type-dependent expression. */
21166
21167 bool
any_type_dependent_arguments_p(const vec<tree,va_gc> * args)21168 any_type_dependent_arguments_p (const vec<tree, va_gc> *args)
21169 {
21170 unsigned int i;
21171 tree arg;
21172
21173 FOR_EACH_VEC_SAFE_ELT (args, i, arg)
21174 {
21175 if (type_dependent_expression_p (arg))
21176 return true;
21177 }
21178 return false;
21179 }
21180
21181 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21182 expressions) contains any type-dependent expressions. */
21183
21184 bool
any_type_dependent_elements_p(const_tree list)21185 any_type_dependent_elements_p (const_tree list)
21186 {
21187 for (; list; list = TREE_CHAIN (list))
21188 if (type_dependent_expression_p (TREE_VALUE (list)))
21189 return true;
21190
21191 return false;
21192 }
21193
21194 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
21195 expressions) contains any value-dependent expressions. */
21196
21197 bool
any_value_dependent_elements_p(const_tree list)21198 any_value_dependent_elements_p (const_tree list)
21199 {
21200 for (; list; list = TREE_CHAIN (list))
21201 if (value_dependent_expression_p (TREE_VALUE (list)))
21202 return true;
21203
21204 return false;
21205 }
21206
21207 /* Returns TRUE if the ARG (a template argument) is dependent. */
21208
21209 bool
dependent_template_arg_p(tree arg)21210 dependent_template_arg_p (tree arg)
21211 {
21212 if (!processing_template_decl)
21213 return false;
21214
21215 /* Assume a template argument that was wrongly written by the user
21216 is dependent. This is consistent with what
21217 any_dependent_template_arguments_p [that calls this function]
21218 does. */
21219 if (!arg || arg == error_mark_node)
21220 return true;
21221
21222 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
21223 arg = ARGUMENT_PACK_SELECT_ARG (arg);
21224
21225 if (TREE_CODE (arg) == TEMPLATE_DECL
21226 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
21227 return dependent_template_p (arg);
21228 else if (ARGUMENT_PACK_P (arg))
21229 {
21230 tree args = ARGUMENT_PACK_ARGS (arg);
21231 int i, len = TREE_VEC_LENGTH (args);
21232 for (i = 0; i < len; ++i)
21233 {
21234 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
21235 return true;
21236 }
21237
21238 return false;
21239 }
21240 else if (TYPE_P (arg))
21241 return dependent_type_p (arg);
21242 else
21243 return (type_dependent_expression_p (arg)
21244 || value_dependent_expression_p (arg));
21245 }
21246
21247 /* Returns true if ARGS (a collection of template arguments) contains
21248 any types that require structural equality testing. */
21249
21250 bool
any_template_arguments_need_structural_equality_p(tree args)21251 any_template_arguments_need_structural_equality_p (tree args)
21252 {
21253 int i;
21254 int j;
21255
21256 if (!args)
21257 return false;
21258 if (args == error_mark_node)
21259 return true;
21260
21261 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
21262 {
21263 tree level = TMPL_ARGS_LEVEL (args, i + 1);
21264 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
21265 {
21266 tree arg = TREE_VEC_ELT (level, j);
21267 tree packed_args = NULL_TREE;
21268 int k, len = 1;
21269
21270 if (ARGUMENT_PACK_P (arg))
21271 {
21272 /* Look inside the argument pack. */
21273 packed_args = ARGUMENT_PACK_ARGS (arg);
21274 len = TREE_VEC_LENGTH (packed_args);
21275 }
21276
21277 for (k = 0; k < len; ++k)
21278 {
21279 if (packed_args)
21280 arg = TREE_VEC_ELT (packed_args, k);
21281
21282 if (error_operand_p (arg))
21283 return true;
21284 else if (TREE_CODE (arg) == TEMPLATE_DECL)
21285 continue;
21286 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
21287 return true;
21288 else if (!TYPE_P (arg) && TREE_TYPE (arg)
21289 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
21290 return true;
21291 }
21292 }
21293 }
21294
21295 return false;
21296 }
21297
21298 /* Returns true if ARGS (a collection of template arguments) contains
21299 any dependent arguments. */
21300
21301 bool
any_dependent_template_arguments_p(const_tree args)21302 any_dependent_template_arguments_p (const_tree args)
21303 {
21304 int i;
21305 int j;
21306
21307 if (!args)
21308 return false;
21309 if (args == error_mark_node)
21310 return true;
21311
21312 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
21313 {
21314 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
21315 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
21316 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
21317 return true;
21318 }
21319
21320 return false;
21321 }
21322
21323 /* Returns TRUE if the template TMPL is dependent. */
21324
21325 bool
dependent_template_p(tree tmpl)21326 dependent_template_p (tree tmpl)
21327 {
21328 if (TREE_CODE (tmpl) == OVERLOAD)
21329 {
21330 while (tmpl)
21331 {
21332 if (dependent_template_p (OVL_CURRENT (tmpl)))
21333 return true;
21334 tmpl = OVL_NEXT (tmpl);
21335 }
21336 return false;
21337 }
21338
21339 /* Template template parameters are dependent. */
21340 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
21341 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
21342 return true;
21343 /* So are names that have not been looked up. */
21344 if (TREE_CODE (tmpl) == SCOPE_REF || identifier_p (tmpl))
21345 return true;
21346 /* So are member templates of dependent classes. */
21347 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
21348 return dependent_type_p (DECL_CONTEXT (tmpl));
21349 return false;
21350 }
21351
21352 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
21353
21354 bool
dependent_template_id_p(tree tmpl,tree args)21355 dependent_template_id_p (tree tmpl, tree args)
21356 {
21357 return (dependent_template_p (tmpl)
21358 || any_dependent_template_arguments_p (args));
21359 }
21360
21361 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
21362 is dependent. */
21363
21364 bool
dependent_omp_for_p(tree declv,tree initv,tree condv,tree incrv)21365 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
21366 {
21367 int i;
21368
21369 if (!processing_template_decl)
21370 return false;
21371
21372 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
21373 {
21374 tree decl = TREE_VEC_ELT (declv, i);
21375 tree init = TREE_VEC_ELT (initv, i);
21376 tree cond = TREE_VEC_ELT (condv, i);
21377 tree incr = TREE_VEC_ELT (incrv, i);
21378
21379 if (type_dependent_expression_p (decl))
21380 return true;
21381
21382 if (init && type_dependent_expression_p (init))
21383 return true;
21384
21385 if (type_dependent_expression_p (cond))
21386 return true;
21387
21388 if (COMPARISON_CLASS_P (cond)
21389 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
21390 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
21391 return true;
21392
21393 if (TREE_CODE (incr) == MODOP_EXPR)
21394 {
21395 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
21396 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
21397 return true;
21398 }
21399 else if (type_dependent_expression_p (incr))
21400 return true;
21401 else if (TREE_CODE (incr) == MODIFY_EXPR)
21402 {
21403 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
21404 return true;
21405 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
21406 {
21407 tree t = TREE_OPERAND (incr, 1);
21408 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
21409 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
21410 return true;
21411 }
21412 }
21413 }
21414
21415 return false;
21416 }
21417
21418 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
21419 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
21420 no such TYPE can be found. Note that this function peers inside
21421 uninstantiated templates and therefore should be used only in
21422 extremely limited situations. ONLY_CURRENT_P restricts this
21423 peering to the currently open classes hierarchy (which is required
21424 when comparing types). */
21425
21426 tree
resolve_typename_type(tree type,bool only_current_p)21427 resolve_typename_type (tree type, bool only_current_p)
21428 {
21429 tree scope;
21430 tree name;
21431 tree decl;
21432 int quals;
21433 tree pushed_scope;
21434 tree result;
21435
21436 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
21437
21438 scope = TYPE_CONTEXT (type);
21439 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
21440 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
21441 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
21442 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
21443 identifier of the TYPENAME_TYPE anymore.
21444 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
21445 TYPENAME_TYPE instead, we avoid messing up with a possible
21446 typedef variant case. */
21447 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
21448
21449 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
21450 it first before we can figure out what NAME refers to. */
21451 if (TREE_CODE (scope) == TYPENAME_TYPE)
21452 {
21453 if (TYPENAME_IS_RESOLVING_P (scope))
21454 /* Given a class template A with a dependent base with nested type C,
21455 typedef typename A::C::C C will land us here, as trying to resolve
21456 the initial A::C leads to the local C typedef, which leads back to
21457 A::C::C. So we break the recursion now. */
21458 return type;
21459 else
21460 scope = resolve_typename_type (scope, only_current_p);
21461 }
21462 /* If we don't know what SCOPE refers to, then we cannot resolve the
21463 TYPENAME_TYPE. */
21464 if (TREE_CODE (scope) == TYPENAME_TYPE)
21465 return type;
21466 /* If the SCOPE is a template type parameter, we have no way of
21467 resolving the name. */
21468 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
21469 return type;
21470 /* If the SCOPE is not the current instantiation, there's no reason
21471 to look inside it. */
21472 if (only_current_p && !currently_open_class (scope))
21473 return type;
21474 /* If this is a typedef, we don't want to look inside (c++/11987). */
21475 if (typedef_variant_p (type))
21476 return type;
21477 /* If SCOPE isn't the template itself, it will not have a valid
21478 TYPE_FIELDS list. */
21479 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
21480 /* scope is either the template itself or a compatible instantiation
21481 like X<T>, so look up the name in the original template. */
21482 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
21483 else
21484 /* scope is a partial instantiation, so we can't do the lookup or we
21485 will lose the template arguments. */
21486 return type;
21487 /* Enter the SCOPE so that name lookup will be resolved as if we
21488 were in the class definition. In particular, SCOPE will no
21489 longer be considered a dependent type. */
21490 pushed_scope = push_scope (scope);
21491 /* Look up the declaration. */
21492 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
21493 tf_warning_or_error);
21494
21495 result = NULL_TREE;
21496
21497 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
21498 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
21499 if (!decl)
21500 /*nop*/;
21501 else if (identifier_p (TYPENAME_TYPE_FULLNAME (type))
21502 && TREE_CODE (decl) == TYPE_DECL)
21503 {
21504 result = TREE_TYPE (decl);
21505 if (result == error_mark_node)
21506 result = NULL_TREE;
21507 }
21508 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
21509 && DECL_CLASS_TEMPLATE_P (decl))
21510 {
21511 tree tmpl;
21512 tree args;
21513 /* Obtain the template and the arguments. */
21514 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
21515 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
21516 /* Instantiate the template. */
21517 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
21518 /*entering_scope=*/0,
21519 tf_error | tf_user);
21520 if (result == error_mark_node)
21521 result = NULL_TREE;
21522 }
21523
21524 /* Leave the SCOPE. */
21525 if (pushed_scope)
21526 pop_scope (pushed_scope);
21527
21528 /* If we failed to resolve it, return the original typename. */
21529 if (!result)
21530 return type;
21531
21532 /* If lookup found a typename type, resolve that too. */
21533 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
21534 {
21535 /* Ill-formed programs can cause infinite recursion here, so we
21536 must catch that. */
21537 TYPENAME_IS_RESOLVING_P (type) = 1;
21538 result = resolve_typename_type (result, only_current_p);
21539 TYPENAME_IS_RESOLVING_P (type) = 0;
21540 }
21541
21542 /* Qualify the resulting type. */
21543 quals = cp_type_quals (type);
21544 if (quals)
21545 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
21546
21547 return result;
21548 }
21549
21550 /* EXPR is an expression which is not type-dependent. Return a proxy
21551 for EXPR that can be used to compute the types of larger
21552 expressions containing EXPR. */
21553
21554 tree
build_non_dependent_expr(tree expr)21555 build_non_dependent_expr (tree expr)
21556 {
21557 tree inner_expr;
21558
21559 #ifdef ENABLE_CHECKING
21560 /* Try to get a constant value for all non-dependent expressions in
21561 order to expose bugs in *_dependent_expression_p and constexpr. */
21562 if (cxx_dialect >= cxx11)
21563 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
21564 #endif
21565
21566 /* Preserve OVERLOADs; the functions must be available to resolve
21567 types. */
21568 inner_expr = expr;
21569 if (TREE_CODE (inner_expr) == STMT_EXPR)
21570 inner_expr = stmt_expr_value_expr (inner_expr);
21571 if (TREE_CODE (inner_expr) == ADDR_EXPR)
21572 inner_expr = TREE_OPERAND (inner_expr, 0);
21573 if (TREE_CODE (inner_expr) == COMPONENT_REF)
21574 inner_expr = TREE_OPERAND (inner_expr, 1);
21575 if (is_overloaded_fn (inner_expr)
21576 || TREE_CODE (inner_expr) == OFFSET_REF)
21577 return expr;
21578 /* There is no need to return a proxy for a variable. */
21579 if (VAR_P (expr))
21580 return expr;
21581 /* Preserve string constants; conversions from string constants to
21582 "char *" are allowed, even though normally a "const char *"
21583 cannot be used to initialize a "char *". */
21584 if (TREE_CODE (expr) == STRING_CST)
21585 return expr;
21586 /* Preserve arithmetic constants, as an optimization -- there is no
21587 reason to create a new node. */
21588 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
21589 return expr;
21590 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
21591 There is at least one place where we want to know that a
21592 particular expression is a throw-expression: when checking a ?:
21593 expression, there are special rules if the second or third
21594 argument is a throw-expression. */
21595 if (TREE_CODE (expr) == THROW_EXPR)
21596 return expr;
21597
21598 /* Don't wrap an initializer list, we need to be able to look inside. */
21599 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
21600 return expr;
21601
21602 /* Don't wrap a dummy object, we need to be able to test for it. */
21603 if (is_dummy_object (expr))
21604 return expr;
21605
21606 if (TREE_CODE (expr) == COND_EXPR)
21607 return build3 (COND_EXPR,
21608 TREE_TYPE (expr),
21609 TREE_OPERAND (expr, 0),
21610 (TREE_OPERAND (expr, 1)
21611 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
21612 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
21613 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
21614 if (TREE_CODE (expr) == COMPOUND_EXPR
21615 && !COMPOUND_EXPR_OVERLOADED (expr))
21616 return build2 (COMPOUND_EXPR,
21617 TREE_TYPE (expr),
21618 TREE_OPERAND (expr, 0),
21619 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
21620
21621 /* If the type is unknown, it can't really be non-dependent */
21622 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
21623
21624 /* Otherwise, build a NON_DEPENDENT_EXPR. */
21625 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
21626 }
21627
21628 /* ARGS is a vector of expressions as arguments to a function call.
21629 Replace the arguments with equivalent non-dependent expressions.
21630 This modifies ARGS in place. */
21631
21632 void
make_args_non_dependent(vec<tree,va_gc> * args)21633 make_args_non_dependent (vec<tree, va_gc> *args)
21634 {
21635 unsigned int ix;
21636 tree arg;
21637
21638 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
21639 {
21640 tree newarg = build_non_dependent_expr (arg);
21641 if (newarg != arg)
21642 (*args)[ix] = newarg;
21643 }
21644 }
21645
21646 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
21647 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
21648 parms. */
21649
21650 static tree
make_auto_1(tree name)21651 make_auto_1 (tree name)
21652 {
21653 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
21654 TYPE_NAME (au) = build_decl (input_location,
21655 TYPE_DECL, name, au);
21656 TYPE_STUB_DECL (au) = TYPE_NAME (au);
21657 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
21658 (0, processing_template_decl + 1, processing_template_decl + 1,
21659 TYPE_NAME (au), NULL_TREE);
21660 TYPE_CANONICAL (au) = canonical_type_parameter (au);
21661 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
21662 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
21663
21664 return au;
21665 }
21666
21667 tree
make_decltype_auto(void)21668 make_decltype_auto (void)
21669 {
21670 return make_auto_1 (get_identifier ("decltype(auto)"));
21671 }
21672
21673 tree
make_auto(void)21674 make_auto (void)
21675 {
21676 return make_auto_1 (get_identifier ("auto"));
21677 }
21678
21679 /* Given type ARG, return std::initializer_list<ARG>. */
21680
21681 static tree
listify(tree arg)21682 listify (tree arg)
21683 {
21684 tree std_init_list = namespace_binding
21685 (get_identifier ("initializer_list"), std_node);
21686 tree argvec;
21687 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
21688 {
21689 error ("deducing from brace-enclosed initializer list requires "
21690 "#include <initializer_list>");
21691 return error_mark_node;
21692 }
21693 argvec = make_tree_vec (1);
21694 TREE_VEC_ELT (argvec, 0) = arg;
21695 return lookup_template_class (std_init_list, argvec, NULL_TREE,
21696 NULL_TREE, 0, tf_warning_or_error);
21697 }
21698
21699 /* Replace auto in TYPE with std::initializer_list<auto>. */
21700
21701 static tree
listify_autos(tree type,tree auto_node)21702 listify_autos (tree type, tree auto_node)
21703 {
21704 tree init_auto = listify (auto_node);
21705 tree argvec = make_tree_vec (1);
21706 TREE_VEC_ELT (argvec, 0) = init_auto;
21707 if (processing_template_decl)
21708 argvec = add_to_template_args (current_template_args (), argvec);
21709 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
21710 }
21711
21712 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
21713 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
21714
21715 tree
do_auto_deduction(tree type,tree init,tree auto_node)21716 do_auto_deduction (tree type, tree init, tree auto_node)
21717 {
21718 tree targs;
21719
21720 if (init == error_mark_node)
21721 return error_mark_node;
21722
21723 if (type_dependent_expression_p (init))
21724 /* Defining a subset of type-dependent expressions that we can deduce
21725 from ahead of time isn't worth the trouble. */
21726 return type;
21727
21728 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
21729 with either a new invented type template parameter U or, if the
21730 initializer is a braced-init-list (8.5.4), with
21731 std::initializer_list<U>. */
21732 if (BRACE_ENCLOSED_INITIALIZER_P (init))
21733 type = listify_autos (type, auto_node);
21734
21735 init = resolve_nondeduced_context (init);
21736
21737 targs = make_tree_vec (1);
21738 if (AUTO_IS_DECLTYPE (auto_node))
21739 {
21740 bool id = (DECL_P (init) || (TREE_CODE (init) == COMPONENT_REF
21741 && !REF_PARENTHESIZED_P (init)));
21742 TREE_VEC_ELT (targs, 0)
21743 = finish_decltype_type (init, id, tf_warning_or_error);
21744 if (type != auto_node)
21745 {
21746 error ("%qT as type rather than plain %<decltype(auto)%>", type);
21747 return error_mark_node;
21748 }
21749 }
21750 else
21751 {
21752 tree parms = build_tree_list (NULL_TREE, type);
21753 tree tparms = make_tree_vec (1);
21754 int val;
21755
21756 TREE_VEC_ELT (tparms, 0)
21757 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
21758 val = type_unification_real (tparms, targs, parms, &init, 1, 0,
21759 DEDUCE_CALL, LOOKUP_NORMAL,
21760 NULL, /*explain_p=*/false);
21761 if (val > 0)
21762 {
21763 if (processing_template_decl)
21764 /* Try again at instantiation time. */
21765 return type;
21766 if (type && type != error_mark_node)
21767 /* If type is error_mark_node a diagnostic must have been
21768 emitted by now. Also, having a mention to '<type error>'
21769 in the diagnostic is not really useful to the user. */
21770 {
21771 if (cfun && auto_node == current_function_auto_return_pattern
21772 && LAMBDA_FUNCTION_P (current_function_decl))
21773 error ("unable to deduce lambda return type from %qE", init);
21774 else
21775 error ("unable to deduce %qT from %qE", type, init);
21776 }
21777 return error_mark_node;
21778 }
21779 }
21780
21781 /* If the list of declarators contains more than one declarator, the type
21782 of each declared variable is determined as described above. If the
21783 type deduced for the template parameter U is not the same in each
21784 deduction, the program is ill-formed. */
21785 if (TREE_TYPE (auto_node)
21786 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
21787 {
21788 if (cfun && auto_node == current_function_auto_return_pattern
21789 && LAMBDA_FUNCTION_P (current_function_decl))
21790 error ("inconsistent types %qT and %qT deduced for "
21791 "lambda return type", TREE_TYPE (auto_node),
21792 TREE_VEC_ELT (targs, 0));
21793 else
21794 error ("inconsistent deduction for %qT: %qT and then %qT",
21795 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
21796 return error_mark_node;
21797 }
21798 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
21799
21800 if (processing_template_decl)
21801 targs = add_to_template_args (current_template_args (), targs);
21802 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
21803 }
21804
21805 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
21806 result. */
21807
21808 tree
splice_late_return_type(tree type,tree late_return_type)21809 splice_late_return_type (tree type, tree late_return_type)
21810 {
21811 tree argvec;
21812
21813 if (late_return_type == NULL_TREE)
21814 return type;
21815 argvec = make_tree_vec (1);
21816 TREE_VEC_ELT (argvec, 0) = late_return_type;
21817 if (processing_template_parmlist)
21818 /* For a late-specified return type in a template type-parameter, we
21819 need to add a dummy argument level for its parmlist. */
21820 argvec = add_to_template_args
21821 (make_tree_vec (processing_template_parmlist), argvec);
21822 if (current_template_parms)
21823 argvec = add_to_template_args (current_template_args (), argvec);
21824 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
21825 }
21826
21827 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
21828 'decltype(auto)'. */
21829
21830 bool
is_auto(const_tree type)21831 is_auto (const_tree type)
21832 {
21833 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
21834 && (TYPE_IDENTIFIER (type) == get_identifier ("auto")
21835 || TYPE_IDENTIFIER (type) == get_identifier ("decltype(auto)")))
21836 return true;
21837 else
21838 return false;
21839 }
21840
21841 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
21842 a use of `auto'. Returns NULL_TREE otherwise. */
21843
21844 tree
type_uses_auto(tree type)21845 type_uses_auto (tree type)
21846 {
21847 return find_type_usage (type, is_auto);
21848 }
21849
21850 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
21851 'decltype(auto)' or a concept. */
21852
21853 bool
is_auto_or_concept(const_tree type)21854 is_auto_or_concept (const_tree type)
21855 {
21856 return is_auto (type); // or concept
21857 }
21858
21859 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
21860 a concept identifier) iff TYPE contains a use of a generic type. Returns
21861 NULL_TREE otherwise. */
21862
21863 tree
type_uses_auto_or_concept(tree type)21864 type_uses_auto_or_concept (tree type)
21865 {
21866 return find_type_usage (type, is_auto_or_concept);
21867 }
21868
21869
21870 /* For a given template T, return the vector of typedefs referenced
21871 in T for which access check is needed at T instantiation time.
21872 T is either a FUNCTION_DECL or a RECORD_TYPE.
21873 Those typedefs were added to T by the function
21874 append_type_to_template_for_access_check. */
21875
21876 vec<qualified_typedef_usage_t, va_gc> *
get_types_needing_access_check(tree t)21877 get_types_needing_access_check (tree t)
21878 {
21879 tree ti;
21880 vec<qualified_typedef_usage_t, va_gc> *result = NULL;
21881
21882 if (!t || t == error_mark_node)
21883 return NULL;
21884
21885 if (!(ti = get_template_info (t)))
21886 return NULL;
21887
21888 if (CLASS_TYPE_P (t)
21889 || TREE_CODE (t) == FUNCTION_DECL)
21890 {
21891 if (!TI_TEMPLATE (ti))
21892 return NULL;
21893
21894 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
21895 }
21896
21897 return result;
21898 }
21899
21900 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
21901 tied to T. That list of typedefs will be access checked at
21902 T instantiation time.
21903 T is either a FUNCTION_DECL or a RECORD_TYPE.
21904 TYPE_DECL is a TYPE_DECL node representing a typedef.
21905 SCOPE is the scope through which TYPE_DECL is accessed.
21906 LOCATION is the location of the usage point of TYPE_DECL.
21907
21908 This function is a subroutine of
21909 append_type_to_template_for_access_check. */
21910
21911 static void
append_type_to_template_for_access_check_1(tree t,tree type_decl,tree scope,location_t location)21912 append_type_to_template_for_access_check_1 (tree t,
21913 tree type_decl,
21914 tree scope,
21915 location_t location)
21916 {
21917 qualified_typedef_usage_t typedef_usage;
21918 tree ti;
21919
21920 if (!t || t == error_mark_node)
21921 return;
21922
21923 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
21924 || CLASS_TYPE_P (t))
21925 && type_decl
21926 && TREE_CODE (type_decl) == TYPE_DECL
21927 && scope);
21928
21929 if (!(ti = get_template_info (t)))
21930 return;
21931
21932 gcc_assert (TI_TEMPLATE (ti));
21933
21934 typedef_usage.typedef_decl = type_decl;
21935 typedef_usage.context = scope;
21936 typedef_usage.locus = location;
21937
21938 vec_safe_push (TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti), typedef_usage);
21939 }
21940
21941 /* Append TYPE_DECL to the template TEMPL.
21942 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
21943 At TEMPL instanciation time, TYPE_DECL will be checked to see
21944 if it can be accessed through SCOPE.
21945 LOCATION is the location of the usage point of TYPE_DECL.
21946
21947 e.g. consider the following code snippet:
21948
21949 class C
21950 {
21951 typedef int myint;
21952 };
21953
21954 template<class U> struct S
21955 {
21956 C::myint mi; // <-- usage point of the typedef C::myint
21957 };
21958
21959 S<char> s;
21960
21961 At S<char> instantiation time, we need to check the access of C::myint
21962 In other words, we need to check the access of the myint typedef through
21963 the C scope. For that purpose, this function will add the myint typedef
21964 and the scope C through which its being accessed to a list of typedefs
21965 tied to the template S. That list will be walked at template instantiation
21966 time and access check performed on each typedefs it contains.
21967 Note that this particular code snippet should yield an error because
21968 myint is private to C. */
21969
21970 void
append_type_to_template_for_access_check(tree templ,tree type_decl,tree scope,location_t location)21971 append_type_to_template_for_access_check (tree templ,
21972 tree type_decl,
21973 tree scope,
21974 location_t location)
21975 {
21976 qualified_typedef_usage_t *iter;
21977 unsigned i;
21978
21979 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
21980
21981 /* Make sure we don't append the type to the template twice. */
21982 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (templ), i, iter)
21983 if (iter->typedef_decl == type_decl && scope == iter->context)
21984 return;
21985
21986 append_type_to_template_for_access_check_1 (templ, type_decl,
21987 scope, location);
21988 }
21989
21990 /* Convert the generic type parameters in PARM that match the types given in the
21991 range [START_IDX, END_IDX) from the current_template_parms into generic type
21992 packs. */
21993
21994 tree
convert_generic_types_to_packs(tree parm,int start_idx,int end_idx)21995 convert_generic_types_to_packs (tree parm, int start_idx, int end_idx)
21996 {
21997 tree current = current_template_parms;
21998 int depth = TMPL_PARMS_DEPTH (current);
21999 current = INNERMOST_TEMPLATE_PARMS (current);
22000 tree replacement = make_tree_vec (TREE_VEC_LENGTH (current));
22001
22002 for (int i = 0; i < start_idx; ++i)
22003 TREE_VEC_ELT (replacement, i)
22004 = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i)));
22005
22006 for (int i = start_idx; i < end_idx; ++i)
22007 {
22008 /* Create a distinct parameter pack type from the current parm and add it
22009 to the replacement args to tsubst below into the generic function
22010 parameter. */
22011
22012 tree o = TREE_TYPE (TREE_VALUE
22013 (TREE_VEC_ELT (current, i)));
22014 tree t = copy_type (o);
22015 TEMPLATE_TYPE_PARM_INDEX (t)
22016 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (o),
22017 o, 0, 0, tf_none);
22018 TREE_TYPE (TEMPLATE_TYPE_DECL (t)) = t;
22019 TYPE_STUB_DECL (t) = TYPE_NAME (t) = TEMPLATE_TYPE_DECL (t);
22020 TYPE_MAIN_VARIANT (t) = t;
22021 TEMPLATE_TYPE_PARAMETER_PACK (t) = true;
22022 TYPE_CANONICAL (t) = canonical_type_parameter (t);
22023 TREE_VEC_ELT (replacement, i) = t;
22024 TREE_VALUE (TREE_VEC_ELT (current, i)) = TREE_CHAIN (t);
22025 }
22026
22027 for (int i = end_idx, e = TREE_VEC_LENGTH (current); i < e; ++i)
22028 TREE_VEC_ELT (replacement, i)
22029 = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i)));
22030
22031 /* If there are more levels then build up the replacement with the outer
22032 template parms. */
22033 if (depth > 1)
22034 replacement = add_to_template_args (template_parms_to_args
22035 (TREE_CHAIN (current_template_parms)),
22036 replacement);
22037
22038 return tsubst (parm, replacement, tf_none, NULL_TREE);
22039 }
22040
22041
22042 /* Set up the hash tables for template instantiations. */
22043
22044 void
init_template_processing(void)22045 init_template_processing (void)
22046 {
22047 decl_specializations = htab_create_ggc (37,
22048 hash_specialization,
22049 eq_specializations,
22050 ggc_free);
22051 type_specializations = htab_create_ggc (37,
22052 hash_specialization,
22053 eq_specializations,
22054 ggc_free);
22055 }
22056
22057 /* Print stats about the template hash tables for -fstats. */
22058
22059 void
print_template_statistics(void)22060 print_template_statistics (void)
22061 {
22062 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
22063 "%f collisions\n", (long) htab_size (decl_specializations),
22064 (long) htab_elements (decl_specializations),
22065 htab_collisions (decl_specializations));
22066 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
22067 "%f collisions\n", (long) htab_size (type_specializations),
22068 (long) htab_elements (type_specializations),
22069 htab_collisions (type_specializations));
22070 }
22071
22072 #include "gt-cp-pt.h"
22073