1 /* Process declarations and variables for C++ compiler.
2 Copyright (C) 1988-2013 Free Software Foundation, Inc.
3 Hacked by Michael Tiemann (tiemann@cygnus.com)
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 3, or (at your option)
10 any later version.
11
12 GCC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21
22 /* Process declarations and symbol lookup for C++ front end.
23 Also constructs types; the standard scalar types at initialization,
24 and structure, union, array and enum types when they are declared. */
25
26 /* ??? not all decl nodes are given the most useful possible
27 line numbers. For example, the CONST_DECLs for enum values. */
28
29 #include "config.h"
30 #include "system.h"
31 #include "coretypes.h"
32 #include "tm.h"
33 #include "tree.h"
34 #include "flags.h"
35 #include "cp-tree.h"
36 #include "decl.h"
37 #include "toplev.h"
38 #include "timevar.h"
39 #include "cpplib.h"
40 #include "target.h"
41 #include "c-family/c-common.h"
42 #include "c-family/c-objc.h"
43 #include "cgraph.h"
44 #include "tree-inline.h"
45 #include "c-family/c-pragma.h"
46 #include "dumpfile.h"
47 #include "intl.h"
48 #include "gimple.h"
49 #include "pointer-set.h"
50 #include "splay-tree.h"
51 #include "langhooks.h"
52 #include "c-family/c-ada-spec.h"
53
54 extern cpp_reader *parse_in;
55
56 /* This structure contains information about the initializations
57 and/or destructions required for a particular priority level. */
58 typedef struct priority_info_s {
59 /* Nonzero if there have been any initializations at this priority
60 throughout the translation unit. */
61 int initializations_p;
62 /* Nonzero if there have been any destructions at this priority
63 throughout the translation unit. */
64 int destructions_p;
65 } *priority_info;
66
67 static void mark_vtable_entries (tree);
68 static bool maybe_emit_vtables (tree);
69 static bool acceptable_java_type (tree);
70 static tree start_objects (int, int);
71 static void finish_objects (int, int, tree);
72 static tree start_static_storage_duration_function (unsigned);
73 static void finish_static_storage_duration_function (tree);
74 static priority_info get_priority_info (int);
75 static void do_static_initialization_or_destruction (tree, bool);
76 static void one_static_initialization_or_destruction (tree, tree, bool);
77 static void generate_ctor_or_dtor_function (bool, int, location_t *);
78 static int generate_ctor_and_dtor_functions_for_priority (splay_tree_node,
79 void *);
80 static tree prune_vars_needing_no_initialization (tree *);
81 static void write_out_vars (tree);
82 static void import_export_class (tree);
83 static tree get_guard_bits (tree);
84 static void determine_visibility_from_class (tree, tree);
85 static bool determine_hidden_inline (tree);
86 static bool decl_defined_p (tree);
87
88 /* A list of static class variables. This is needed, because a
89 static class variable can be declared inside the class without
90 an initializer, and then initialized, statically, outside the class. */
91 static GTY(()) vec<tree, va_gc> *pending_statics;
92
93 /* A list of functions which were declared inline, but which we
94 may need to emit outline anyway. */
95 static GTY(()) vec<tree, va_gc> *deferred_fns;
96
97 /* A list of decls that use types with no linkage, which we need to make
98 sure are defined. */
99 static GTY(()) vec<tree, va_gc> *no_linkage_decls;
100
101 /* Nonzero if we're done parsing and into end-of-file activities. */
102
103 int at_eof;
104
105
106
107 /* Return a member function type (a METHOD_TYPE), given FNTYPE (a
108 FUNCTION_TYPE), CTYPE (class type), and QUALS (the cv-qualifiers
109 that apply to the function). */
110
111 tree
build_memfn_type(tree fntype,tree ctype,cp_cv_quals quals,cp_ref_qualifier rqual)112 build_memfn_type (tree fntype, tree ctype, cp_cv_quals quals,
113 cp_ref_qualifier rqual)
114 {
115 tree raises;
116 tree attrs;
117 int type_quals;
118
119 if (fntype == error_mark_node || ctype == error_mark_node)
120 return error_mark_node;
121
122 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
123 || TREE_CODE (fntype) == METHOD_TYPE);
124
125 type_quals = quals & ~TYPE_QUAL_RESTRICT;
126 ctype = cp_build_qualified_type (ctype, type_quals);
127 raises = TYPE_RAISES_EXCEPTIONS (fntype);
128 attrs = TYPE_ATTRIBUTES (fntype);
129 fntype = build_method_type_directly (ctype, TREE_TYPE (fntype),
130 (TREE_CODE (fntype) == METHOD_TYPE
131 ? TREE_CHAIN (TYPE_ARG_TYPES (fntype))
132 : TYPE_ARG_TYPES (fntype)));
133 if (attrs)
134 fntype = cp_build_type_attribute_variant (fntype, attrs);
135 if (rqual)
136 fntype = build_ref_qualified_type (fntype, rqual);
137 if (raises)
138 fntype = build_exception_variant (fntype, raises);
139
140 return fntype;
141 }
142
143 /* Return a variant of FNTYPE, a FUNCTION_TYPE or METHOD_TYPE, with its
144 return type changed to NEW_RET. */
145
146 tree
change_return_type(tree new_ret,tree fntype)147 change_return_type (tree new_ret, tree fntype)
148 {
149 tree newtype;
150 tree args = TYPE_ARG_TYPES (fntype);
151 tree raises = TYPE_RAISES_EXCEPTIONS (fntype);
152 tree attrs = TYPE_ATTRIBUTES (fntype);
153
154 if (new_ret == error_mark_node)
155 return fntype;
156
157 if (same_type_p (new_ret, TREE_TYPE (fntype)))
158 return fntype;
159
160 if (TREE_CODE (fntype) == FUNCTION_TYPE)
161 {
162 newtype = build_function_type (new_ret, args);
163 newtype = apply_memfn_quals (newtype,
164 type_memfn_quals (fntype),
165 type_memfn_rqual (fntype));
166 }
167 else
168 newtype = build_method_type_directly
169 (class_of_this_parm (fntype), new_ret, TREE_CHAIN (args));
170 if (raises)
171 newtype = build_exception_variant (newtype, raises);
172 if (attrs)
173 newtype = cp_build_type_attribute_variant (newtype, attrs);
174
175 return newtype;
176 }
177
178 /* Build a PARM_DECL with NAME and TYPE, and set DECL_ARG_TYPE
179 appropriately. */
180
181 tree
cp_build_parm_decl(tree name,tree type)182 cp_build_parm_decl (tree name, tree type)
183 {
184 tree parm = build_decl (input_location,
185 PARM_DECL, name, type);
186 /* DECL_ARG_TYPE is only used by the back end and the back end never
187 sees templates. */
188 if (!processing_template_decl)
189 DECL_ARG_TYPE (parm) = type_passed_as (type);
190
191 /* If the type is a pack expansion, then we have a function
192 parameter pack. */
193 if (type && TREE_CODE (type) == TYPE_PACK_EXPANSION)
194 FUNCTION_PARAMETER_PACK_P (parm) = 1;
195
196 return parm;
197 }
198
199 /* Returns a PARM_DECL for a parameter of the indicated TYPE, with the
200 indicated NAME. */
201
202 tree
build_artificial_parm(tree name,tree type)203 build_artificial_parm (tree name, tree type)
204 {
205 tree parm = cp_build_parm_decl (name, type);
206 DECL_ARTIFICIAL (parm) = 1;
207 /* All our artificial parms are implicitly `const'; they cannot be
208 assigned to. */
209 TREE_READONLY (parm) = 1;
210 return parm;
211 }
212
213 /* Constructors for types with virtual baseclasses need an "in-charge" flag
214 saying whether this constructor is responsible for initialization of
215 virtual baseclasses or not. All destructors also need this "in-charge"
216 flag, which additionally determines whether or not the destructor should
217 free the memory for the object.
218
219 This function adds the "in-charge" flag to member function FN if
220 appropriate. It is called from grokclassfn and tsubst.
221 FN must be either a constructor or destructor.
222
223 The in-charge flag follows the 'this' parameter, and is followed by the
224 VTT parm (if any), then the user-written parms. */
225
226 void
maybe_retrofit_in_chrg(tree fn)227 maybe_retrofit_in_chrg (tree fn)
228 {
229 tree basetype, arg_types, parms, parm, fntype;
230
231 /* If we've already add the in-charge parameter don't do it again. */
232 if (DECL_HAS_IN_CHARGE_PARM_P (fn))
233 return;
234
235 /* When processing templates we can't know, in general, whether or
236 not we're going to have virtual baseclasses. */
237 if (processing_template_decl)
238 return;
239
240 /* We don't need an in-charge parameter for constructors that don't
241 have virtual bases. */
242 if (DECL_CONSTRUCTOR_P (fn)
243 && !CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)))
244 return;
245
246 arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
247 basetype = TREE_TYPE (TREE_VALUE (arg_types));
248 arg_types = TREE_CHAIN (arg_types);
249
250 parms = DECL_CHAIN (DECL_ARGUMENTS (fn));
251
252 /* If this is a subobject constructor or destructor, our caller will
253 pass us a pointer to our VTT. */
254 if (CLASSTYPE_VBASECLASSES (DECL_CONTEXT (fn)))
255 {
256 parm = build_artificial_parm (vtt_parm_identifier, vtt_parm_type);
257
258 /* First add it to DECL_ARGUMENTS between 'this' and the real args... */
259 DECL_CHAIN (parm) = parms;
260 parms = parm;
261
262 /* ...and then to TYPE_ARG_TYPES. */
263 arg_types = hash_tree_chain (vtt_parm_type, arg_types);
264
265 DECL_HAS_VTT_PARM_P (fn) = 1;
266 }
267
268 /* Then add the in-charge parm (before the VTT parm). */
269 parm = build_artificial_parm (in_charge_identifier, integer_type_node);
270 DECL_CHAIN (parm) = parms;
271 parms = parm;
272 arg_types = hash_tree_chain (integer_type_node, arg_types);
273
274 /* Insert our new parameter(s) into the list. */
275 DECL_CHAIN (DECL_ARGUMENTS (fn)) = parms;
276
277 /* And rebuild the function type. */
278 fntype = build_method_type_directly (basetype, TREE_TYPE (TREE_TYPE (fn)),
279 arg_types);
280 if (TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)))
281 fntype = build_exception_variant (fntype,
282 TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn)));
283 if (TYPE_ATTRIBUTES (TREE_TYPE (fn)))
284 fntype = (cp_build_type_attribute_variant
285 (fntype, TYPE_ATTRIBUTES (TREE_TYPE (fn))));
286 TREE_TYPE (fn) = fntype;
287
288 /* Now we've got the in-charge parameter. */
289 DECL_HAS_IN_CHARGE_PARM_P (fn) = 1;
290 }
291
292 /* Classes overload their constituent function names automatically.
293 When a function name is declared in a record structure,
294 its name is changed to it overloaded name. Since names for
295 constructors and destructors can conflict, we place a leading
296 '$' for destructors.
297
298 CNAME is the name of the class we are grokking for.
299
300 FUNCTION is a FUNCTION_DECL. It was created by `grokdeclarator'.
301
302 FLAGS contains bits saying what's special about today's
303 arguments. DTOR_FLAG == DESTRUCTOR.
304
305 If FUNCTION is a destructor, then we must add the `auto-delete' field
306 as a second parameter. There is some hair associated with the fact
307 that we must "declare" this variable in the manner consistent with the
308 way the rest of the arguments were declared.
309
310 QUALS are the qualifiers for the this pointer. */
311
312 void
grokclassfn(tree ctype,tree function,enum overload_flags flags)313 grokclassfn (tree ctype, tree function, enum overload_flags flags)
314 {
315 tree fn_name = DECL_NAME (function);
316
317 /* Even within an `extern "C"' block, members get C++ linkage. See
318 [dcl.link] for details. */
319 SET_DECL_LANGUAGE (function, lang_cplusplus);
320
321 if (fn_name == NULL_TREE)
322 {
323 error ("name missing for member function");
324 fn_name = get_identifier ("<anonymous>");
325 DECL_NAME (function) = fn_name;
326 }
327
328 DECL_CONTEXT (function) = ctype;
329
330 if (flags == DTOR_FLAG)
331 DECL_DESTRUCTOR_P (function) = 1;
332
333 if (flags == DTOR_FLAG || DECL_CONSTRUCTOR_P (function))
334 maybe_retrofit_in_chrg (function);
335 }
336
337 /* Create an ARRAY_REF, checking for the user doing things backwards
338 along the way. DECLTYPE_P is for N3276, as in the parser. */
339
340 tree
grok_array_decl(location_t loc,tree array_expr,tree index_exp,bool decltype_p)341 grok_array_decl (location_t loc, tree array_expr, tree index_exp,
342 bool decltype_p)
343 {
344 tree type;
345 tree expr;
346 tree orig_array_expr = array_expr;
347 tree orig_index_exp = index_exp;
348
349 if (error_operand_p (array_expr) || error_operand_p (index_exp))
350 return error_mark_node;
351
352 if (processing_template_decl)
353 {
354 if (type_dependent_expression_p (array_expr)
355 || type_dependent_expression_p (index_exp))
356 return build_min_nt_loc (loc, ARRAY_REF, array_expr, index_exp,
357 NULL_TREE, NULL_TREE);
358 array_expr = build_non_dependent_expr (array_expr);
359 index_exp = build_non_dependent_expr (index_exp);
360 }
361
362 type = TREE_TYPE (array_expr);
363 gcc_assert (type);
364 type = non_reference (type);
365
366 /* If they have an `operator[]', use that. */
367 if (MAYBE_CLASS_TYPE_P (type) || MAYBE_CLASS_TYPE_P (TREE_TYPE (index_exp)))
368 {
369 tsubst_flags_t complain = tf_warning_or_error;
370 if (decltype_p)
371 complain |= tf_decltype;
372 expr = build_new_op (loc, ARRAY_REF, LOOKUP_NORMAL, array_expr,
373 index_exp, NULL_TREE, /*overload=*/NULL, complain);
374 }
375 else
376 {
377 tree p1, p2, i1, i2;
378
379 /* Otherwise, create an ARRAY_REF for a pointer or array type.
380 It is a little-known fact that, if `a' is an array and `i' is
381 an int, you can write `i[a]', which means the same thing as
382 `a[i]'. */
383 if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
384 p1 = array_expr;
385 else
386 p1 = build_expr_type_conversion (WANT_POINTER, array_expr, false);
387
388 if (TREE_CODE (TREE_TYPE (index_exp)) == ARRAY_TYPE)
389 p2 = index_exp;
390 else
391 p2 = build_expr_type_conversion (WANT_POINTER, index_exp, false);
392
393 i1 = build_expr_type_conversion (WANT_INT | WANT_ENUM, array_expr,
394 false);
395 i2 = build_expr_type_conversion (WANT_INT | WANT_ENUM, index_exp,
396 false);
397
398 if ((p1 && i2) && (i1 && p2))
399 error ("ambiguous conversion for array subscript");
400
401 if (p1 && i2)
402 array_expr = p1, index_exp = i2;
403 else if (i1 && p2)
404 array_expr = p2, index_exp = i1;
405 else
406 {
407 error ("invalid types %<%T[%T]%> for array subscript",
408 type, TREE_TYPE (index_exp));
409 return error_mark_node;
410 }
411
412 if (array_expr == error_mark_node || index_exp == error_mark_node)
413 error ("ambiguous conversion for array subscript");
414
415 expr = build_array_ref (input_location, array_expr, index_exp);
416 }
417 if (processing_template_decl && expr != error_mark_node)
418 return build_min_non_dep (ARRAY_REF, expr, orig_array_expr, orig_index_exp,
419 NULL_TREE, NULL_TREE);
420 return expr;
421 }
422
423 /* Given the cast expression EXP, checking out its validity. Either return
424 an error_mark_node if there was an unavoidable error, return a cast to
425 void for trying to delete a pointer w/ the value 0, or return the
426 call to delete. If DOING_VEC is true, we handle things differently
427 for doing an array delete.
428 Implements ARM $5.3.4. This is called from the parser. */
429
430 tree
delete_sanity(tree exp,tree size,bool doing_vec,int use_global_delete,tsubst_flags_t complain)431 delete_sanity (tree exp, tree size, bool doing_vec, int use_global_delete,
432 tsubst_flags_t complain)
433 {
434 tree t, type;
435
436 if (exp == error_mark_node)
437 return exp;
438
439 if (processing_template_decl)
440 {
441 t = build_min (DELETE_EXPR, void_type_node, exp, size);
442 DELETE_EXPR_USE_GLOBAL (t) = use_global_delete;
443 DELETE_EXPR_USE_VEC (t) = doing_vec;
444 TREE_SIDE_EFFECTS (t) = 1;
445 return t;
446 }
447
448 /* An array can't have been allocated by new, so complain. */
449 if (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE)
450 warning (0, "deleting array %q#E", exp);
451
452 t = build_expr_type_conversion (WANT_POINTER, exp, true);
453
454 if (t == NULL_TREE || t == error_mark_node)
455 {
456 error ("type %q#T argument given to %<delete%>, expected pointer",
457 TREE_TYPE (exp));
458 return error_mark_node;
459 }
460
461 type = TREE_TYPE (t);
462
463 /* As of Valley Forge, you can delete a pointer to const. */
464
465 /* You can't delete functions. */
466 if (TREE_CODE (TREE_TYPE (type)) == FUNCTION_TYPE)
467 {
468 error ("cannot delete a function. Only pointer-to-objects are "
469 "valid arguments to %<delete%>");
470 return error_mark_node;
471 }
472
473 /* Deleting ptr to void is undefined behavior [expr.delete/3]. */
474 if (TREE_CODE (TREE_TYPE (type)) == VOID_TYPE)
475 {
476 warning (0, "deleting %qT is undefined", type);
477 doing_vec = 0;
478 }
479
480 /* Deleting a pointer with the value zero is valid and has no effect. */
481 if (integer_zerop (t))
482 return build1 (NOP_EXPR, void_type_node, t);
483
484 if (doing_vec)
485 return build_vec_delete (t, /*maxindex=*/NULL_TREE,
486 sfk_deleting_destructor,
487 use_global_delete, complain);
488 else
489 return build_delete (type, t, sfk_deleting_destructor,
490 LOOKUP_NORMAL, use_global_delete,
491 complain);
492 }
493
494 /* Report an error if the indicated template declaration is not the
495 sort of thing that should be a member template. */
496
497 void
check_member_template(tree tmpl)498 check_member_template (tree tmpl)
499 {
500 tree decl;
501
502 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
503 decl = DECL_TEMPLATE_RESULT (tmpl);
504
505 if (TREE_CODE (decl) == FUNCTION_DECL
506 || DECL_ALIAS_TEMPLATE_P (tmpl)
507 || (TREE_CODE (decl) == TYPE_DECL
508 && MAYBE_CLASS_TYPE_P (TREE_TYPE (decl))))
509 {
510 /* The parser rejects template declarations in local classes. */
511 gcc_assert (!current_function_decl);
512 /* The parser rejects any use of virtual in a function template. */
513 gcc_assert (!(TREE_CODE (decl) == FUNCTION_DECL
514 && DECL_VIRTUAL_P (decl)));
515
516 /* The debug-information generating code doesn't know what to do
517 with member templates. */
518 DECL_IGNORED_P (tmpl) = 1;
519 }
520 else
521 error ("template declaration of %q#D", decl);
522 }
523
524 /* Return true iff TYPE is a valid Java parameter or return type. */
525
526 static bool
acceptable_java_type(tree type)527 acceptable_java_type (tree type)
528 {
529 if (type == error_mark_node)
530 return false;
531
532 if (TREE_CODE (type) == VOID_TYPE || TYPE_FOR_JAVA (type))
533 return true;
534 if (TREE_CODE (type) == POINTER_TYPE || TREE_CODE (type) == REFERENCE_TYPE)
535 {
536 type = TREE_TYPE (type);
537 if (TREE_CODE (type) == RECORD_TYPE)
538 {
539 tree args; int i;
540 if (! TYPE_FOR_JAVA (type))
541 return false;
542 if (! CLASSTYPE_TEMPLATE_INFO (type))
543 return true;
544 args = CLASSTYPE_TI_ARGS (type);
545 i = TREE_VEC_LENGTH (args);
546 while (--i >= 0)
547 {
548 type = TREE_VEC_ELT (args, i);
549 if (TREE_CODE (type) == POINTER_TYPE)
550 type = TREE_TYPE (type);
551 if (! TYPE_FOR_JAVA (type))
552 return false;
553 }
554 return true;
555 }
556 }
557 return false;
558 }
559
560 /* For a METHOD in a Java class CTYPE, return true if
561 the parameter and return types are valid Java types.
562 Otherwise, print appropriate error messages, and return false. */
563
564 bool
check_java_method(tree method)565 check_java_method (tree method)
566 {
567 bool jerr = false;
568 tree arg_types = TYPE_ARG_TYPES (TREE_TYPE (method));
569 tree ret_type = TREE_TYPE (TREE_TYPE (method));
570
571 if (!acceptable_java_type (ret_type))
572 {
573 error ("Java method %qD has non-Java return type %qT",
574 method, ret_type);
575 jerr = true;
576 }
577
578 arg_types = TREE_CHAIN (arg_types);
579 if (DECL_HAS_IN_CHARGE_PARM_P (method))
580 arg_types = TREE_CHAIN (arg_types);
581 if (DECL_HAS_VTT_PARM_P (method))
582 arg_types = TREE_CHAIN (arg_types);
583
584 for (; arg_types != NULL_TREE; arg_types = TREE_CHAIN (arg_types))
585 {
586 tree type = TREE_VALUE (arg_types);
587 if (!acceptable_java_type (type))
588 {
589 if (type != error_mark_node)
590 error ("Java method %qD has non-Java parameter type %qT",
591 method, type);
592 jerr = true;
593 }
594 }
595 return !jerr;
596 }
597
598 /* Sanity check: report error if this function FUNCTION is not
599 really a member of the class (CTYPE) it is supposed to belong to.
600 TEMPLATE_PARMS is used to specify the template parameters of a member
601 template passed as FUNCTION_DECL. If the member template is passed as a
602 TEMPLATE_DECL, it can be NULL since the parameters can be extracted
603 from the declaration. If the function is not a function template, it
604 must be NULL.
605 It returns the original declaration for the function, NULL_TREE if
606 no declaration was found, error_mark_node if an error was emitted. */
607
608 tree
check_classfn(tree ctype,tree function,tree template_parms)609 check_classfn (tree ctype, tree function, tree template_parms)
610 {
611 int ix;
612 bool is_template;
613 tree pushed_scope;
614
615 if (DECL_USE_TEMPLATE (function)
616 && !(TREE_CODE (function) == TEMPLATE_DECL
617 && DECL_TEMPLATE_SPECIALIZATION (function))
618 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (function)))
619 /* Since this is a specialization of a member template,
620 we're not going to find the declaration in the class.
621 For example, in:
622
623 struct S { template <typename T> void f(T); };
624 template <> void S::f(int);
625
626 we're not going to find `S::f(int)', but there's no
627 reason we should, either. We let our callers know we didn't
628 find the method, but we don't complain. */
629 return NULL_TREE;
630
631 /* Basic sanity check: for a template function, the template parameters
632 either were not passed, or they are the same of DECL_TEMPLATE_PARMS. */
633 if (TREE_CODE (function) == TEMPLATE_DECL)
634 {
635 if (template_parms
636 && !comp_template_parms (template_parms,
637 DECL_TEMPLATE_PARMS (function)))
638 {
639 error ("template parameter lists provided don%'t match the "
640 "template parameters of %qD", function);
641 return error_mark_node;
642 }
643 template_parms = DECL_TEMPLATE_PARMS (function);
644 }
645
646 /* OK, is this a definition of a member template? */
647 is_template = (template_parms != NULL_TREE);
648
649 /* We must enter the scope here, because conversion operators are
650 named by target type, and type equivalence relies on typenames
651 resolving within the scope of CTYPE. */
652 pushed_scope = push_scope (ctype);
653 ix = class_method_index_for_fn (complete_type (ctype), function);
654 if (ix >= 0)
655 {
656 vec<tree, va_gc> *methods = CLASSTYPE_METHOD_VEC (ctype);
657 tree fndecls, fndecl = 0;
658 bool is_conv_op;
659 const char *format = NULL;
660
661 for (fndecls = (*methods)[ix];
662 fndecls; fndecls = OVL_NEXT (fndecls))
663 {
664 tree p1, p2;
665
666 fndecl = OVL_CURRENT (fndecls);
667 p1 = TYPE_ARG_TYPES (TREE_TYPE (function));
668 p2 = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
669
670 /* We cannot simply call decls_match because this doesn't
671 work for static member functions that are pretending to
672 be methods, and because the name may have been changed by
673 asm("new_name"). */
674
675 /* Get rid of the this parameter on functions that become
676 static. */
677 if (DECL_STATIC_FUNCTION_P (fndecl)
678 && TREE_CODE (TREE_TYPE (function)) == METHOD_TYPE)
679 p1 = TREE_CHAIN (p1);
680
681 /* A member template definition only matches a member template
682 declaration. */
683 if (is_template != (TREE_CODE (fndecl) == TEMPLATE_DECL))
684 continue;
685
686 /* ref-qualifier or absence of same must match. */
687 if (type_memfn_rqual (TREE_TYPE (function))
688 != type_memfn_rqual (TREE_TYPE (fndecl)))
689 continue;
690
691 /* While finding a match, same types and params are not enough
692 if the function is versioned. Also check version ("target")
693 attributes. */
694 if (same_type_p (TREE_TYPE (TREE_TYPE (function)),
695 TREE_TYPE (TREE_TYPE (fndecl)))
696 && compparms (p1, p2)
697 && !targetm.target_option.function_versions (function, fndecl)
698 && (!is_template
699 || comp_template_parms (template_parms,
700 DECL_TEMPLATE_PARMS (fndecl)))
701 && (DECL_TEMPLATE_SPECIALIZATION (function)
702 == DECL_TEMPLATE_SPECIALIZATION (fndecl))
703 && (!DECL_TEMPLATE_SPECIALIZATION (function)
704 || (DECL_TI_TEMPLATE (function)
705 == DECL_TI_TEMPLATE (fndecl))))
706 break;
707 }
708 if (fndecls)
709 {
710 if (pushed_scope)
711 pop_scope (pushed_scope);
712 return OVL_CURRENT (fndecls);
713 }
714
715 error_at (DECL_SOURCE_LOCATION (function),
716 "prototype for %q#D does not match any in class %qT",
717 function, ctype);
718 is_conv_op = DECL_CONV_FN_P (fndecl);
719
720 if (is_conv_op)
721 ix = CLASSTYPE_FIRST_CONVERSION_SLOT;
722 fndecls = (*methods)[ix];
723 while (fndecls)
724 {
725 fndecl = OVL_CURRENT (fndecls);
726 fndecls = OVL_NEXT (fndecls);
727
728 if (!fndecls && is_conv_op)
729 {
730 if (methods->length () > (size_t) ++ix)
731 {
732 fndecls = (*methods)[ix];
733 if (!DECL_CONV_FN_P (OVL_CURRENT (fndecls)))
734 {
735 fndecls = NULL_TREE;
736 is_conv_op = false;
737 }
738 }
739 else
740 is_conv_op = false;
741 }
742 if (format)
743 format = " %+#D";
744 else if (fndecls)
745 format = N_("candidates are: %+#D");
746 else
747 format = N_("candidate is: %+#D");
748 error (format, fndecl);
749 }
750 }
751 else if (!COMPLETE_TYPE_P (ctype))
752 cxx_incomplete_type_error (function, ctype);
753 else
754 error ("no %q#D member function declared in class %qT",
755 function, ctype);
756
757 if (pushed_scope)
758 pop_scope (pushed_scope);
759 return error_mark_node;
760 }
761
762 /* DECL is a function with vague linkage. Remember it so that at the
763 end of the translation unit we can decide whether or not to emit
764 it. */
765
766 void
note_vague_linkage_fn(tree decl)767 note_vague_linkage_fn (tree decl)
768 {
769 DECL_DEFER_OUTPUT (decl) = 1;
770 vec_safe_push (deferred_fns, decl);
771 }
772
773 /* We have just processed the DECL, which is a static data member.
774 The other parameters are as for cp_finish_decl. */
775
776 void
finish_static_data_member_decl(tree decl,tree init,bool init_const_expr_p,tree asmspec_tree,int flags)777 finish_static_data_member_decl (tree decl,
778 tree init, bool init_const_expr_p,
779 tree asmspec_tree,
780 int flags)
781 {
782 DECL_CONTEXT (decl) = current_class_type;
783
784 /* We cannot call pushdecl here, because that would fill in the
785 TREE_CHAIN of our decl. Instead, we modify cp_finish_decl to do
786 the right thing, namely, to put this decl out straight away. */
787
788 if (! processing_template_decl)
789 vec_safe_push (pending_statics, decl);
790
791 if (LOCAL_CLASS_P (current_class_type)
792 /* We already complained about the template definition. */
793 && !DECL_TEMPLATE_INSTANTIATION (decl))
794 permerror (input_location, "local class %q#T shall not have static data member %q#D",
795 current_class_type, decl);
796
797 DECL_IN_AGGR_P (decl) = 1;
798
799 if (TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE
800 && TYPE_DOMAIN (TREE_TYPE (decl)) == NULL_TREE)
801 SET_VAR_HAD_UNKNOWN_BOUND (decl);
802
803 cp_finish_decl (decl, init, init_const_expr_p, asmspec_tree, flags);
804 }
805
806 /* DECLARATOR and DECLSPECS correspond to a class member. The other
807 parameters are as for cp_finish_decl. Return the DECL for the
808 class member declared. */
809
810 tree
grokfield(const cp_declarator * declarator,cp_decl_specifier_seq * declspecs,tree init,bool init_const_expr_p,tree asmspec_tree,tree attrlist)811 grokfield (const cp_declarator *declarator,
812 cp_decl_specifier_seq *declspecs,
813 tree init, bool init_const_expr_p,
814 tree asmspec_tree,
815 tree attrlist)
816 {
817 tree value;
818 const char *asmspec = 0;
819 int flags;
820 tree name;
821
822 if (init
823 && TREE_CODE (init) == TREE_LIST
824 && TREE_VALUE (init) == error_mark_node
825 && TREE_CHAIN (init) == NULL_TREE)
826 init = NULL_TREE;
827
828 value = grokdeclarator (declarator, declspecs, FIELD, init != 0, &attrlist);
829 if (! value || error_operand_p (value))
830 /* friend or constructor went bad. */
831 return error_mark_node;
832
833 if (TREE_CODE (value) == TYPE_DECL && init)
834 {
835 error ("typedef %qD is initialized (use decltype instead)", value);
836 init = NULL_TREE;
837 }
838
839 /* Pass friendly classes back. */
840 if (value == void_type_node)
841 return value;
842
843 /* Pass friend decls back. */
844 if ((TREE_CODE (value) == FUNCTION_DECL
845 || TREE_CODE (value) == TEMPLATE_DECL)
846 && DECL_CONTEXT (value) != current_class_type)
847 return value;
848
849 name = DECL_NAME (value);
850
851 if (name != NULL_TREE)
852 {
853 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
854 {
855 error ("explicit template argument list not allowed");
856 return error_mark_node;
857 }
858
859 if (IDENTIFIER_POINTER (name)[0] == '_'
860 && ! strcmp (IDENTIFIER_POINTER (name), "_vptr"))
861 error ("member %qD conflicts with virtual function table field name",
862 value);
863 }
864
865 /* Stash away type declarations. */
866 if (TREE_CODE (value) == TYPE_DECL)
867 {
868 DECL_NONLOCAL (value) = 1;
869 DECL_CONTEXT (value) = current_class_type;
870
871 if (attrlist)
872 {
873 int attrflags = 0;
874
875 /* If this is a typedef that names the class for linkage purposes
876 (7.1.3p8), apply any attributes directly to the type. */
877 if (TAGGED_TYPE_P (TREE_TYPE (value))
878 && value == TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (value))))
879 attrflags = ATTR_FLAG_TYPE_IN_PLACE;
880
881 cplus_decl_attributes (&value, attrlist, attrflags);
882 }
883
884 if (decl_spec_seq_has_spec_p (declspecs, ds_typedef)
885 && TREE_TYPE (value) != error_mark_node
886 && TYPE_NAME (TYPE_MAIN_VARIANT (TREE_TYPE (value))) != value)
887 set_underlying_type (value);
888
889 /* It's important that push_template_decl below follows
890 set_underlying_type above so that the created template
891 carries the properly set type of VALUE. */
892 if (processing_template_decl)
893 value = push_template_decl (value);
894
895 record_locally_defined_typedef (value);
896 return value;
897 }
898
899 if (DECL_IN_AGGR_P (value))
900 {
901 error ("%qD is already defined in %qT", value, DECL_CONTEXT (value));
902 return void_type_node;
903 }
904
905 if (asmspec_tree && asmspec_tree != error_mark_node)
906 asmspec = TREE_STRING_POINTER (asmspec_tree);
907
908 if (init)
909 {
910 if (TREE_CODE (value) == FUNCTION_DECL)
911 {
912 /* Initializers for functions are rejected early in the parser.
913 If we get here, it must be a pure specifier for a method. */
914 if (init == ridpointers[(int)RID_DELETE])
915 {
916 DECL_DELETED_FN (value) = 1;
917 DECL_DECLARED_INLINE_P (value) = 1;
918 DECL_INITIAL (value) = error_mark_node;
919 }
920 else if (init == ridpointers[(int)RID_DEFAULT])
921 {
922 if (defaultable_fn_check (value))
923 {
924 DECL_DEFAULTED_FN (value) = 1;
925 DECL_INITIALIZED_IN_CLASS_P (value) = 1;
926 DECL_DECLARED_INLINE_P (value) = 1;
927 }
928 }
929 else if (TREE_CODE (init) == DEFAULT_ARG)
930 error ("invalid initializer for member function %qD", value);
931 else if (TREE_CODE (TREE_TYPE (value)) == METHOD_TYPE)
932 {
933 if (integer_zerop (init))
934 DECL_PURE_VIRTUAL_P (value) = 1;
935 else if (error_operand_p (init))
936 ; /* An error has already been reported. */
937 else
938 error ("invalid initializer for member function %qD",
939 value);
940 }
941 else
942 {
943 gcc_assert (TREE_CODE (TREE_TYPE (value)) == FUNCTION_TYPE);
944 error ("initializer specified for static member function %qD",
945 value);
946 }
947 }
948 else if (TREE_CODE (value) == FIELD_DECL)
949 /* C++11 NSDMI, keep going. */;
950 else if (TREE_CODE (value) != VAR_DECL)
951 gcc_unreachable ();
952 else if (!processing_template_decl)
953 {
954 if (TREE_CODE (init) == CONSTRUCTOR)
955 init = digest_init (TREE_TYPE (value), init, tf_warning_or_error);
956 init = maybe_constant_init (init);
957
958 if (init != error_mark_node && !TREE_CONSTANT (init))
959 {
960 /* We can allow references to things that are effectively
961 static, since references are initialized with the
962 address. */
963 if (TREE_CODE (TREE_TYPE (value)) != REFERENCE_TYPE
964 || (TREE_STATIC (init) == 0
965 && (!DECL_P (init) || DECL_EXTERNAL (init) == 0)))
966 {
967 error ("field initializer is not constant");
968 init = error_mark_node;
969 }
970 }
971 }
972 }
973
974 if (processing_template_decl
975 && (TREE_CODE (value) == VAR_DECL || TREE_CODE (value) == FUNCTION_DECL))
976 {
977 value = push_template_decl (value);
978 if (error_operand_p (value))
979 return error_mark_node;
980 }
981
982 if (attrlist)
983 cplus_decl_attributes (&value, attrlist, 0);
984
985 if (init && BRACE_ENCLOSED_INITIALIZER_P (init)
986 && CONSTRUCTOR_IS_DIRECT_INIT (init))
987 flags = LOOKUP_NORMAL;
988 else
989 flags = LOOKUP_IMPLICIT;
990
991 switch (TREE_CODE (value))
992 {
993 case VAR_DECL:
994 finish_static_data_member_decl (value, init, init_const_expr_p,
995 asmspec_tree, flags);
996 return value;
997
998 case FIELD_DECL:
999 if (asmspec)
1000 error ("%<asm%> specifiers are not permitted on non-static data members");
1001 if (DECL_INITIAL (value) == error_mark_node)
1002 init = error_mark_node;
1003 cp_finish_decl (value, init, /*init_const_expr_p=*/false,
1004 NULL_TREE, flags);
1005 DECL_IN_AGGR_P (value) = 1;
1006 return value;
1007
1008 case FUNCTION_DECL:
1009 if (asmspec)
1010 set_user_assembler_name (value, asmspec);
1011
1012 cp_finish_decl (value,
1013 /*init=*/NULL_TREE,
1014 /*init_const_expr_p=*/false,
1015 asmspec_tree, flags);
1016
1017 /* Pass friends back this way. */
1018 if (DECL_FRIEND_P (value))
1019 return void_type_node;
1020
1021 DECL_IN_AGGR_P (value) = 1;
1022 return value;
1023
1024 default:
1025 gcc_unreachable ();
1026 }
1027 return NULL_TREE;
1028 }
1029
1030 /* Like `grokfield', but for bitfields.
1031 WIDTH is non-NULL for bit fields only, and is an INTEGER_CST node. */
1032
1033 tree
grokbitfield(const cp_declarator * declarator,cp_decl_specifier_seq * declspecs,tree width,tree attrlist)1034 grokbitfield (const cp_declarator *declarator,
1035 cp_decl_specifier_seq *declspecs, tree width,
1036 tree attrlist)
1037 {
1038 tree value = grokdeclarator (declarator, declspecs, BITFIELD, 0, &attrlist);
1039
1040 if (value == error_mark_node)
1041 return NULL_TREE; /* friends went bad. */
1042
1043 /* Pass friendly classes back. */
1044 if (TREE_CODE (value) == VOID_TYPE)
1045 return void_type_node;
1046
1047 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (value))
1048 && (POINTER_TYPE_P (value)
1049 || !dependent_type_p (TREE_TYPE (value))))
1050 {
1051 error ("bit-field %qD with non-integral type", value);
1052 return error_mark_node;
1053 }
1054
1055 if (TREE_CODE (value) == TYPE_DECL)
1056 {
1057 error ("cannot declare %qD to be a bit-field type", value);
1058 return NULL_TREE;
1059 }
1060
1061 /* Usually, finish_struct_1 catches bitfields with invalid types.
1062 But, in the case of bitfields with function type, we confuse
1063 ourselves into thinking they are member functions, so we must
1064 check here. */
1065 if (TREE_CODE (value) == FUNCTION_DECL)
1066 {
1067 error ("cannot declare bit-field %qD with function type",
1068 DECL_NAME (value));
1069 return NULL_TREE;
1070 }
1071
1072 if (DECL_IN_AGGR_P (value))
1073 {
1074 error ("%qD is already defined in the class %qT", value,
1075 DECL_CONTEXT (value));
1076 return void_type_node;
1077 }
1078
1079 if (TREE_STATIC (value))
1080 {
1081 error ("static member %qD cannot be a bit-field", value);
1082 return NULL_TREE;
1083 }
1084 cp_finish_decl (value, NULL_TREE, false, NULL_TREE, 0);
1085
1086 if (width != error_mark_node)
1087 {
1088 /* The width must be an integer type. */
1089 if (!type_dependent_expression_p (width)
1090 && !INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (TREE_TYPE (width)))
1091 error ("width of bit-field %qD has non-integral type %qT", value,
1092 TREE_TYPE (width));
1093 DECL_INITIAL (value) = width;
1094 SET_DECL_C_BIT_FIELD (value);
1095 }
1096
1097 DECL_IN_AGGR_P (value) = 1;
1098
1099 if (attrlist)
1100 cplus_decl_attributes (&value, attrlist, /*flags=*/0);
1101
1102 return value;
1103 }
1104
1105
1106 /* Returns true iff ATTR is an attribute which needs to be applied at
1107 instantiation time rather than template definition time. */
1108
1109 static bool
is_late_template_attribute(tree attr,tree decl)1110 is_late_template_attribute (tree attr, tree decl)
1111 {
1112 tree name = get_attribute_name (attr);
1113 tree args = TREE_VALUE (attr);
1114 const struct attribute_spec *spec = lookup_attribute_spec (name);
1115 tree arg;
1116
1117 if (!spec)
1118 /* Unknown attribute. */
1119 return false;
1120
1121 /* Attribute weak handling wants to write out assembly right away. */
1122 if (is_attribute_p ("weak", name))
1123 return true;
1124
1125 /* Attribute unused is applied directly, as it appertains to
1126 decls. */
1127 if (is_attribute_p ("unused", name))
1128 return false;
1129
1130 /* If any of the arguments are dependent expressions, we can't evaluate
1131 the attribute until instantiation time. */
1132 for (arg = args; arg; arg = TREE_CHAIN (arg))
1133 {
1134 tree t = TREE_VALUE (arg);
1135
1136 /* If the first attribute argument is an identifier, only consider
1137 second and following arguments. Attributes like mode, format,
1138 cleanup and several target specific attributes aren't late
1139 just because they have an IDENTIFIER_NODE as first argument. */
1140 if (arg == args && TREE_CODE (t) == IDENTIFIER_NODE)
1141 continue;
1142
1143 if (value_dependent_expression_p (t)
1144 || type_dependent_expression_p (t))
1145 return true;
1146 }
1147
1148 if (TREE_CODE (decl) == TYPE_DECL
1149 || TYPE_P (decl)
1150 || spec->type_required)
1151 {
1152 tree type = TYPE_P (decl) ? decl : TREE_TYPE (decl);
1153
1154 /* We can't apply any attributes to a completely unknown type until
1155 instantiation time. */
1156 enum tree_code code = TREE_CODE (type);
1157 if (code == TEMPLATE_TYPE_PARM
1158 || code == BOUND_TEMPLATE_TEMPLATE_PARM
1159 || code == TYPENAME_TYPE)
1160 return true;
1161 /* Also defer most attributes on dependent types. This is not
1162 necessary in all cases, but is the better default. */
1163 else if (dependent_type_p (type)
1164 /* But attribute visibility specifically works on
1165 templates. */
1166 && !is_attribute_p ("visibility", name))
1167 return true;
1168 else
1169 return false;
1170 }
1171 else
1172 return false;
1173 }
1174
1175 /* ATTR_P is a list of attributes. Remove any attributes which need to be
1176 applied at instantiation time and return them. If IS_DEPENDENT is true,
1177 the declaration itself is dependent, so all attributes should be applied
1178 at instantiation time. */
1179
1180 static tree
splice_template_attributes(tree * attr_p,tree decl)1181 splice_template_attributes (tree *attr_p, tree decl)
1182 {
1183 tree *p = attr_p;
1184 tree late_attrs = NULL_TREE;
1185 tree *q = &late_attrs;
1186
1187 if (!p)
1188 return NULL_TREE;
1189
1190 for (; *p; )
1191 {
1192 if (is_late_template_attribute (*p, decl))
1193 {
1194 ATTR_IS_DEPENDENT (*p) = 1;
1195 *q = *p;
1196 *p = TREE_CHAIN (*p);
1197 q = &TREE_CHAIN (*q);
1198 *q = NULL_TREE;
1199 }
1200 else
1201 p = &TREE_CHAIN (*p);
1202 }
1203
1204 return late_attrs;
1205 }
1206
1207 /* Remove any late attributes from the list in ATTR_P and attach them to
1208 DECL_P. */
1209
1210 static void
save_template_attributes(tree * attr_p,tree * decl_p)1211 save_template_attributes (tree *attr_p, tree *decl_p)
1212 {
1213 tree late_attrs = splice_template_attributes (attr_p, *decl_p);
1214 tree *q;
1215 tree old_attrs = NULL_TREE;
1216
1217 if (!late_attrs)
1218 return;
1219
1220 if (DECL_P (*decl_p))
1221 q = &DECL_ATTRIBUTES (*decl_p);
1222 else
1223 q = &TYPE_ATTRIBUTES (*decl_p);
1224
1225 old_attrs = *q;
1226
1227 /* Merge the late attributes at the beginning with the attribute
1228 list. */
1229 late_attrs = merge_attributes (late_attrs, *q);
1230 *q = late_attrs;
1231
1232 if (!DECL_P (*decl_p) && *decl_p == TYPE_MAIN_VARIANT (*decl_p))
1233 {
1234 /* We've added new attributes directly to the main variant, so
1235 now we need to update all of the other variants to include
1236 these new attributes. */
1237 tree variant;
1238 for (variant = TYPE_NEXT_VARIANT (*decl_p); variant;
1239 variant = TYPE_NEXT_VARIANT (variant))
1240 {
1241 gcc_assert (TYPE_ATTRIBUTES (variant) == old_attrs);
1242 TYPE_ATTRIBUTES (variant) = TYPE_ATTRIBUTES (*decl_p);
1243 }
1244 }
1245 }
1246
1247 /* Like reconstruct_complex_type, but handle also template trees. */
1248
1249 tree
cp_reconstruct_complex_type(tree type,tree bottom)1250 cp_reconstruct_complex_type (tree type, tree bottom)
1251 {
1252 tree inner, outer;
1253
1254 if (TREE_CODE (type) == POINTER_TYPE)
1255 {
1256 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1257 outer = build_pointer_type_for_mode (inner, TYPE_MODE (type),
1258 TYPE_REF_CAN_ALIAS_ALL (type));
1259 }
1260 else if (TREE_CODE (type) == REFERENCE_TYPE)
1261 {
1262 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1263 outer = build_reference_type_for_mode (inner, TYPE_MODE (type),
1264 TYPE_REF_CAN_ALIAS_ALL (type));
1265 }
1266 else if (TREE_CODE (type) == ARRAY_TYPE)
1267 {
1268 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1269 outer = build_cplus_array_type (inner, TYPE_DOMAIN (type));
1270 /* Don't call cp_build_qualified_type on ARRAY_TYPEs, the
1271 element type qualification will be handled by the recursive
1272 cp_reconstruct_complex_type call and cp_build_qualified_type
1273 for ARRAY_TYPEs changes the element type. */
1274 return outer;
1275 }
1276 else if (TREE_CODE (type) == FUNCTION_TYPE)
1277 {
1278 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1279 outer = build_function_type (inner, TYPE_ARG_TYPES (type));
1280 outer = apply_memfn_quals (outer,
1281 type_memfn_quals (type),
1282 type_memfn_rqual (type));
1283 }
1284 else if (TREE_CODE (type) == METHOD_TYPE)
1285 {
1286 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1287 /* The build_method_type_directly() routine prepends 'this' to argument list,
1288 so we must compensate by getting rid of it. */
1289 outer
1290 = build_method_type_directly
1291 (class_of_this_parm (type), inner,
1292 TREE_CHAIN (TYPE_ARG_TYPES (type)));
1293 }
1294 else if (TREE_CODE (type) == OFFSET_TYPE)
1295 {
1296 inner = cp_reconstruct_complex_type (TREE_TYPE (type), bottom);
1297 outer = build_offset_type (TYPE_OFFSET_BASETYPE (type), inner);
1298 }
1299 else
1300 return bottom;
1301
1302 if (TYPE_ATTRIBUTES (type))
1303 outer = cp_build_type_attribute_variant (outer, TYPE_ATTRIBUTES (type));
1304 return cp_build_qualified_type (outer, cp_type_quals (type));
1305 }
1306
1307 /* Replaces any constexpr expression that may be into the attributes
1308 arguments with their reduced value. */
1309
1310 static void
cp_check_const_attributes(tree attributes)1311 cp_check_const_attributes (tree attributes)
1312 {
1313 tree attr;
1314 for (attr = attributes; attr; attr = TREE_CHAIN (attr))
1315 {
1316 tree arg;
1317 for (arg = TREE_VALUE (attr); arg; arg = TREE_CHAIN (arg))
1318 {
1319 tree expr = TREE_VALUE (arg);
1320 if (EXPR_P (expr))
1321 TREE_VALUE (arg) = maybe_constant_value (expr);
1322 }
1323 }
1324 }
1325
1326 /* Like decl_attributes, but handle C++ complexity. */
1327
1328 void
cplus_decl_attributes(tree * decl,tree attributes,int flags)1329 cplus_decl_attributes (tree *decl, tree attributes, int flags)
1330 {
1331 if (*decl == NULL_TREE || *decl == void_type_node
1332 || *decl == error_mark_node)
1333 return;
1334
1335 if (processing_template_decl)
1336 {
1337 if (check_for_bare_parameter_packs (attributes))
1338 return;
1339
1340 save_template_attributes (&attributes, decl);
1341 }
1342
1343 cp_check_const_attributes (attributes);
1344
1345 if (TREE_CODE (*decl) == TEMPLATE_DECL)
1346 decl = &DECL_TEMPLATE_RESULT (*decl);
1347
1348 decl_attributes (decl, attributes, flags);
1349
1350 if (TREE_CODE (*decl) == TYPE_DECL)
1351 SET_IDENTIFIER_TYPE_VALUE (DECL_NAME (*decl), TREE_TYPE (*decl));
1352 }
1353
1354 /* Walks through the namespace- or function-scope anonymous union
1355 OBJECT, with the indicated TYPE, building appropriate VAR_DECLs.
1356 Returns one of the fields for use in the mangled name. */
1357
1358 static tree
build_anon_union_vars(tree type,tree object)1359 build_anon_union_vars (tree type, tree object)
1360 {
1361 tree main_decl = NULL_TREE;
1362 tree field;
1363
1364 /* Rather than write the code to handle the non-union case,
1365 just give an error. */
1366 if (TREE_CODE (type) != UNION_TYPE)
1367 {
1368 error ("anonymous struct not inside named type");
1369 return error_mark_node;
1370 }
1371
1372 for (field = TYPE_FIELDS (type);
1373 field != NULL_TREE;
1374 field = DECL_CHAIN (field))
1375 {
1376 tree decl;
1377 tree ref;
1378
1379 if (DECL_ARTIFICIAL (field))
1380 continue;
1381 if (TREE_CODE (field) != FIELD_DECL)
1382 {
1383 permerror (input_location, "%q+#D invalid; an anonymous union can only "
1384 "have non-static data members", field);
1385 continue;
1386 }
1387
1388 if (TREE_PRIVATE (field))
1389 permerror (input_location, "private member %q+#D in anonymous union", field);
1390 else if (TREE_PROTECTED (field))
1391 permerror (input_location, "protected member %q+#D in anonymous union", field);
1392
1393 if (processing_template_decl)
1394 ref = build_min_nt_loc (UNKNOWN_LOCATION, COMPONENT_REF, object,
1395 DECL_NAME (field), NULL_TREE);
1396 else
1397 ref = build_class_member_access_expr (object, field, NULL_TREE,
1398 false, tf_warning_or_error);
1399
1400 if (DECL_NAME (field))
1401 {
1402 tree base;
1403
1404 decl = build_decl (input_location,
1405 VAR_DECL, DECL_NAME (field), TREE_TYPE (field));
1406 DECL_ANON_UNION_VAR_P (decl) = 1;
1407 DECL_ARTIFICIAL (decl) = 1;
1408
1409 base = get_base_address (object);
1410 TREE_PUBLIC (decl) = TREE_PUBLIC (base);
1411 TREE_STATIC (decl) = TREE_STATIC (base);
1412 DECL_EXTERNAL (decl) = DECL_EXTERNAL (base);
1413
1414 SET_DECL_VALUE_EXPR (decl, ref);
1415 DECL_HAS_VALUE_EXPR_P (decl) = 1;
1416
1417 decl = pushdecl (decl);
1418 }
1419 else if (ANON_AGGR_TYPE_P (TREE_TYPE (field)))
1420 decl = build_anon_union_vars (TREE_TYPE (field), ref);
1421 else
1422 decl = 0;
1423
1424 if (main_decl == NULL_TREE)
1425 main_decl = decl;
1426 }
1427
1428 return main_decl;
1429 }
1430
1431 /* Finish off the processing of a UNION_TYPE structure. If the union is an
1432 anonymous union, then all members must be laid out together. PUBLIC_P
1433 is nonzero if this union is not declared static. */
1434
1435 void
finish_anon_union(tree anon_union_decl)1436 finish_anon_union (tree anon_union_decl)
1437 {
1438 tree type;
1439 tree main_decl;
1440 bool public_p;
1441
1442 if (anon_union_decl == error_mark_node)
1443 return;
1444
1445 type = TREE_TYPE (anon_union_decl);
1446 public_p = TREE_PUBLIC (anon_union_decl);
1447
1448 /* The VAR_DECL's context is the same as the TYPE's context. */
1449 DECL_CONTEXT (anon_union_decl) = DECL_CONTEXT (TYPE_NAME (type));
1450
1451 if (TYPE_FIELDS (type) == NULL_TREE)
1452 return;
1453
1454 if (public_p)
1455 {
1456 error ("namespace-scope anonymous aggregates must be static");
1457 return;
1458 }
1459
1460 main_decl = build_anon_union_vars (type, anon_union_decl);
1461 if (main_decl == error_mark_node)
1462 return;
1463 if (main_decl == NULL_TREE)
1464 {
1465 warning (0, "anonymous union with no members");
1466 return;
1467 }
1468
1469 if (!processing_template_decl)
1470 {
1471 /* Use main_decl to set the mangled name. */
1472 DECL_NAME (anon_union_decl) = DECL_NAME (main_decl);
1473 maybe_commonize_var (anon_union_decl);
1474 if (TREE_STATIC (anon_union_decl) || DECL_EXTERNAL (anon_union_decl))
1475 mangle_decl (anon_union_decl);
1476 DECL_NAME (anon_union_decl) = NULL_TREE;
1477 }
1478
1479 pushdecl (anon_union_decl);
1480 cp_finish_decl (anon_union_decl, NULL_TREE, false, NULL_TREE, 0);
1481 }
1482
1483 /* Auxiliary functions to make type signatures for
1484 `operator new' and `operator delete' correspond to
1485 what compiler will be expecting. */
1486
1487 tree
coerce_new_type(tree type)1488 coerce_new_type (tree type)
1489 {
1490 int e = 0;
1491 tree args = TYPE_ARG_TYPES (type);
1492
1493 gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
1494
1495 if (!same_type_p (TREE_TYPE (type), ptr_type_node))
1496 {
1497 e = 1;
1498 error ("%<operator new%> must return type %qT", ptr_type_node);
1499 }
1500
1501 if (args && args != void_list_node)
1502 {
1503 if (TREE_PURPOSE (args))
1504 {
1505 /* [basic.stc.dynamic.allocation]
1506
1507 The first parameter shall not have an associated default
1508 argument. */
1509 error ("the first parameter of %<operator new%> cannot "
1510 "have a default argument");
1511 /* Throw away the default argument. */
1512 TREE_PURPOSE (args) = NULL_TREE;
1513 }
1514
1515 if (!same_type_p (TREE_VALUE (args), size_type_node))
1516 {
1517 e = 2;
1518 args = TREE_CHAIN (args);
1519 }
1520 }
1521 else
1522 e = 2;
1523
1524 if (e == 2)
1525 permerror (input_location, "%<operator new%> takes type %<size_t%> (%qT) "
1526 "as first parameter", size_type_node);
1527
1528 switch (e)
1529 {
1530 case 2:
1531 args = tree_cons (NULL_TREE, size_type_node, args);
1532 /* Fall through. */
1533 case 1:
1534 type = build_exception_variant
1535 (build_function_type (ptr_type_node, args),
1536 TYPE_RAISES_EXCEPTIONS (type));
1537 /* Fall through. */
1538 default:;
1539 }
1540 return type;
1541 }
1542
1543 tree
coerce_delete_type(tree type)1544 coerce_delete_type (tree type)
1545 {
1546 int e = 0;
1547 tree args = TYPE_ARG_TYPES (type);
1548
1549 gcc_assert (TREE_CODE (type) == FUNCTION_TYPE);
1550
1551 if (!same_type_p (TREE_TYPE (type), void_type_node))
1552 {
1553 e = 1;
1554 error ("%<operator delete%> must return type %qT", void_type_node);
1555 }
1556
1557 if (!args || args == void_list_node
1558 || !same_type_p (TREE_VALUE (args), ptr_type_node))
1559 {
1560 e = 2;
1561 if (args && args != void_list_node)
1562 args = TREE_CHAIN (args);
1563 error ("%<operator delete%> takes type %qT as first parameter",
1564 ptr_type_node);
1565 }
1566 switch (e)
1567 {
1568 case 2:
1569 args = tree_cons (NULL_TREE, ptr_type_node, args);
1570 /* Fall through. */
1571 case 1:
1572 type = build_exception_variant
1573 (build_function_type (void_type_node, args),
1574 TYPE_RAISES_EXCEPTIONS (type));
1575 /* Fall through. */
1576 default:;
1577 }
1578
1579 return type;
1580 }
1581
1582 /* DECL is a VAR_DECL for a vtable: walk through the entries in the vtable
1583 and mark them as needed. */
1584
1585 static void
mark_vtable_entries(tree decl)1586 mark_vtable_entries (tree decl)
1587 {
1588 tree fnaddr;
1589 unsigned HOST_WIDE_INT idx;
1590
1591 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (DECL_INITIAL (decl)),
1592 idx, fnaddr)
1593 {
1594 tree fn;
1595
1596 STRIP_NOPS (fnaddr);
1597
1598 if (TREE_CODE (fnaddr) != ADDR_EXPR
1599 && TREE_CODE (fnaddr) != FDESC_EXPR)
1600 /* This entry is an offset: a virtual base class offset, a
1601 virtual call offset, an RTTI offset, etc. */
1602 continue;
1603
1604 fn = TREE_OPERAND (fnaddr, 0);
1605 TREE_ADDRESSABLE (fn) = 1;
1606 /* When we don't have vcall offsets, we output thunks whenever
1607 we output the vtables that contain them. With vcall offsets,
1608 we know all the thunks we'll need when we emit a virtual
1609 function, so we emit the thunks there instead. */
1610 if (DECL_THUNK_P (fn))
1611 use_thunk (fn, /*emit_p=*/0);
1612 mark_used (fn);
1613 }
1614 }
1615
1616 /* Set DECL up to have the closest approximation of "initialized common"
1617 linkage available. */
1618
1619 void
comdat_linkage(tree decl)1620 comdat_linkage (tree decl)
1621 {
1622 if (flag_weak)
1623 make_decl_one_only (decl, cxx_comdat_group (decl));
1624 else if (TREE_CODE (decl) == FUNCTION_DECL
1625 || (TREE_CODE (decl) == VAR_DECL && DECL_ARTIFICIAL (decl)))
1626 /* We can just emit function and compiler-generated variables
1627 statically; having multiple copies is (for the most part) only
1628 a waste of space.
1629
1630 There are two correctness issues, however: the address of a
1631 template instantiation with external linkage should be the
1632 same, independent of what translation unit asks for the
1633 address, and this will not hold when we emit multiple copies of
1634 the function. However, there's little else we can do.
1635
1636 Also, by default, the typeinfo implementation assumes that
1637 there will be only one copy of the string used as the name for
1638 each type. Therefore, if weak symbols are unavailable, the
1639 run-time library should perform a more conservative check; it
1640 should perform a string comparison, rather than an address
1641 comparison. */
1642 TREE_PUBLIC (decl) = 0;
1643 else
1644 {
1645 /* Static data member template instantiations, however, cannot
1646 have multiple copies. */
1647 if (DECL_INITIAL (decl) == 0
1648 || DECL_INITIAL (decl) == error_mark_node)
1649 DECL_COMMON (decl) = 1;
1650 else if (EMPTY_CONSTRUCTOR_P (DECL_INITIAL (decl)))
1651 {
1652 DECL_COMMON (decl) = 1;
1653 DECL_INITIAL (decl) = error_mark_node;
1654 }
1655 else if (!DECL_EXPLICIT_INSTANTIATION (decl))
1656 {
1657 /* We can't do anything useful; leave vars for explicit
1658 instantiation. */
1659 DECL_EXTERNAL (decl) = 1;
1660 DECL_NOT_REALLY_EXTERN (decl) = 0;
1661 }
1662 }
1663
1664 DECL_COMDAT (decl) = 1;
1665 }
1666
1667 /* For win32 we also want to put explicit instantiations in
1668 linkonce sections, so that they will be merged with implicit
1669 instantiations; otherwise we get duplicate symbol errors.
1670 For Darwin we do not want explicit instantiations to be
1671 linkonce. */
1672
1673 void
maybe_make_one_only(tree decl)1674 maybe_make_one_only (tree decl)
1675 {
1676 /* We used to say that this was not necessary on targets that support weak
1677 symbols, because the implicit instantiations will defer to the explicit
1678 one. However, that's not actually the case in SVR4; a strong definition
1679 after a weak one is an error. Also, not making explicit
1680 instantiations one_only means that we can end up with two copies of
1681 some template instantiations. */
1682 if (! flag_weak)
1683 return;
1684
1685 /* We can't set DECL_COMDAT on functions, or cp_finish_file will think
1686 we can get away with not emitting them if they aren't used. We need
1687 to for variables so that cp_finish_decl will update their linkage,
1688 because their DECL_INITIAL may not have been set properly yet. */
1689
1690 if (!TARGET_WEAK_NOT_IN_ARCHIVE_TOC
1691 || (! DECL_EXPLICIT_INSTANTIATION (decl)
1692 && ! DECL_TEMPLATE_SPECIALIZATION (decl)))
1693 {
1694 make_decl_one_only (decl, cxx_comdat_group (decl));
1695
1696 if (TREE_CODE (decl) == VAR_DECL)
1697 {
1698 DECL_COMDAT (decl) = 1;
1699 /* Mark it needed so we don't forget to emit it. */
1700 mark_decl_referenced (decl);
1701 TREE_USED (decl) = 1;
1702 }
1703 }
1704 }
1705
1706 /* Returns true iff DECL, a FUNCTION_DECL or VAR_DECL, has vague linkage.
1707 This predicate will give the right answer during parsing of the
1708 function, which other tests may not. */
1709
1710 bool
vague_linkage_p(tree decl)1711 vague_linkage_p (tree decl)
1712 {
1713 /* Unfortunately, import_export_decl has not always been called
1714 before the function is processed, so we cannot simply check
1715 DECL_COMDAT. */
1716 return (DECL_COMDAT (decl)
1717 || (((TREE_CODE (decl) == FUNCTION_DECL
1718 && DECL_DECLARED_INLINE_P (decl))
1719 || (DECL_LANG_SPECIFIC (decl)
1720 && DECL_TEMPLATE_INSTANTIATION (decl)))
1721 && TREE_PUBLIC (decl)));
1722 }
1723
1724 /* Determine whether or not we want to specifically import or export CTYPE,
1725 using various heuristics. */
1726
1727 static void
import_export_class(tree ctype)1728 import_export_class (tree ctype)
1729 {
1730 /* -1 for imported, 1 for exported. */
1731 int import_export = 0;
1732
1733 /* It only makes sense to call this function at EOF. The reason is
1734 that this function looks at whether or not the first non-inline
1735 non-abstract virtual member function has been defined in this
1736 translation unit. But, we can't possibly know that until we've
1737 seen the entire translation unit. */
1738 gcc_assert (at_eof);
1739
1740 if (CLASSTYPE_INTERFACE_KNOWN (ctype))
1741 return;
1742
1743 /* If MULTIPLE_SYMBOL_SPACES is set and we saw a #pragma interface,
1744 we will have CLASSTYPE_INTERFACE_ONLY set but not
1745 CLASSTYPE_INTERFACE_KNOWN. In that case, we don't want to use this
1746 heuristic because someone will supply a #pragma implementation
1747 elsewhere, and deducing it here would produce a conflict. */
1748 if (CLASSTYPE_INTERFACE_ONLY (ctype))
1749 return;
1750
1751 if (lookup_attribute ("dllimport", TYPE_ATTRIBUTES (ctype)))
1752 import_export = -1;
1753 else if (lookup_attribute ("dllexport", TYPE_ATTRIBUTES (ctype)))
1754 import_export = 1;
1755 else if (CLASSTYPE_IMPLICIT_INSTANTIATION (ctype)
1756 && !flag_implicit_templates)
1757 /* For a template class, without -fimplicit-templates, check the
1758 repository. If the virtual table is assigned to this
1759 translation unit, then export the class; otherwise, import
1760 it. */
1761 import_export = repo_export_class_p (ctype) ? 1 : -1;
1762 else if (TYPE_POLYMORPHIC_P (ctype))
1763 {
1764 /* The ABI specifies that the virtual table and associated
1765 information are emitted with the key method, if any. */
1766 tree method = CLASSTYPE_KEY_METHOD (ctype);
1767 /* If weak symbol support is not available, then we must be
1768 careful not to emit the vtable when the key function is
1769 inline. An inline function can be defined in multiple
1770 translation units. If we were to emit the vtable in each
1771 translation unit containing a definition, we would get
1772 multiple definition errors at link-time. */
1773 if (method && (flag_weak || ! DECL_DECLARED_INLINE_P (method)))
1774 import_export = (DECL_REALLY_EXTERN (method) ? -1 : 1);
1775 }
1776
1777 /* When MULTIPLE_SYMBOL_SPACES is set, we cannot count on seeing
1778 a definition anywhere else. */
1779 if (MULTIPLE_SYMBOL_SPACES && import_export == -1)
1780 import_export = 0;
1781
1782 /* Allow back ends the chance to overrule the decision. */
1783 if (targetm.cxx.import_export_class)
1784 import_export = targetm.cxx.import_export_class (ctype, import_export);
1785
1786 if (import_export)
1787 {
1788 SET_CLASSTYPE_INTERFACE_KNOWN (ctype);
1789 CLASSTYPE_INTERFACE_ONLY (ctype) = (import_export < 0);
1790 }
1791 }
1792
1793 /* Return true if VAR has already been provided to the back end; in that
1794 case VAR should not be modified further by the front end. */
1795 static bool
var_finalized_p(tree var)1796 var_finalized_p (tree var)
1797 {
1798 return varpool_node_for_decl (var)->finalized;
1799 }
1800
1801 /* DECL is a VAR_DECL or FUNCTION_DECL which, for whatever reason,
1802 must be emitted in this translation unit. Mark it as such. */
1803
1804 void
mark_needed(tree decl)1805 mark_needed (tree decl)
1806 {
1807 TREE_USED (decl) = 1;
1808 mark_decl_referenced (decl);
1809 }
1810
1811 /* DECL is either a FUNCTION_DECL or a VAR_DECL. This function
1812 returns true if a definition of this entity should be provided in
1813 this object file. Callers use this function to determine whether
1814 or not to let the back end know that a definition of DECL is
1815 available in this translation unit. */
1816
1817 bool
decl_needed_p(tree decl)1818 decl_needed_p (tree decl)
1819 {
1820 gcc_assert (TREE_CODE (decl) == VAR_DECL
1821 || TREE_CODE (decl) == FUNCTION_DECL);
1822 /* This function should only be called at the end of the translation
1823 unit. We cannot be sure of whether or not something will be
1824 COMDAT until that point. */
1825 gcc_assert (at_eof);
1826
1827 /* All entities with external linkage that are not COMDAT should be
1828 emitted; they may be referred to from other object files. */
1829 if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl))
1830 return true;
1831 /* If this entity was used, let the back end see it; it will decide
1832 whether or not to emit it into the object file. */
1833 if (TREE_USED (decl))
1834 return true;
1835 /* Functions marked "dllexport" must be emitted so that they are
1836 visible to other DLLs. */
1837 if (flag_keep_inline_dllexport
1838 && lookup_attribute ("dllexport", DECL_ATTRIBUTES (decl)))
1839 return true;
1840 /* Otherwise, DECL does not need to be emitted -- yet. A subsequent
1841 reference to DECL might cause it to be emitted later. */
1842 return false;
1843 }
1844
1845 /* If necessary, write out the vtables for the dynamic class CTYPE.
1846 Returns true if any vtables were emitted. */
1847
1848 static bool
maybe_emit_vtables(tree ctype)1849 maybe_emit_vtables (tree ctype)
1850 {
1851 tree vtbl;
1852 tree primary_vtbl;
1853 int needed = 0;
1854 struct varpool_node *current = NULL, *last = NULL;
1855
1856 /* If the vtables for this class have already been emitted there is
1857 nothing more to do. */
1858 primary_vtbl = CLASSTYPE_VTABLES (ctype);
1859 if (var_finalized_p (primary_vtbl))
1860 return false;
1861 /* Ignore dummy vtables made by get_vtable_decl. */
1862 if (TREE_TYPE (primary_vtbl) == void_type_node)
1863 return false;
1864
1865 /* On some targets, we cannot determine the key method until the end
1866 of the translation unit -- which is when this function is
1867 called. */
1868 if (!targetm.cxx.key_method_may_be_inline ())
1869 determine_key_method (ctype);
1870
1871 /* See if any of the vtables are needed. */
1872 for (vtbl = CLASSTYPE_VTABLES (ctype); vtbl; vtbl = DECL_CHAIN (vtbl))
1873 {
1874 import_export_decl (vtbl);
1875 if (DECL_NOT_REALLY_EXTERN (vtbl) && decl_needed_p (vtbl))
1876 needed = 1;
1877 }
1878 if (!needed)
1879 {
1880 /* If the references to this class' vtables are optimized away,
1881 still emit the appropriate debugging information. See
1882 dfs_debug_mark. */
1883 if (DECL_COMDAT (primary_vtbl)
1884 && CLASSTYPE_DEBUG_REQUESTED (ctype))
1885 note_debug_info_needed (ctype);
1886 return false;
1887 }
1888
1889 /* The ABI requires that we emit all of the vtables if we emit any
1890 of them. */
1891 for (vtbl = CLASSTYPE_VTABLES (ctype); vtbl; vtbl = DECL_CHAIN (vtbl))
1892 {
1893 /* Mark entities references from the virtual table as used. */
1894 mark_vtable_entries (vtbl);
1895
1896 if (TREE_TYPE (DECL_INITIAL (vtbl)) == 0)
1897 {
1898 vec<tree, va_gc> *cleanups = NULL;
1899 tree expr = store_init_value (vtbl, DECL_INITIAL (vtbl), &cleanups,
1900 LOOKUP_NORMAL);
1901
1902 /* It had better be all done at compile-time. */
1903 gcc_assert (!expr && !cleanups);
1904 }
1905
1906 /* Write it out. */
1907 DECL_EXTERNAL (vtbl) = 0;
1908 rest_of_decl_compilation (vtbl, 1, 1);
1909
1910 /* Because we're only doing syntax-checking, we'll never end up
1911 actually marking the variable as written. */
1912 if (flag_syntax_only)
1913 TREE_ASM_WRITTEN (vtbl) = 1;
1914 else if (DECL_ONE_ONLY (vtbl))
1915 {
1916 current = varpool_node_for_decl (vtbl);
1917 if (last)
1918 symtab_add_to_same_comdat_group ((symtab_node) current, (symtab_node) last);
1919 last = current;
1920 }
1921 }
1922
1923 /* Since we're writing out the vtable here, also write the debug
1924 info. */
1925 note_debug_info_needed (ctype);
1926
1927 return true;
1928 }
1929
1930 /* A special return value from type_visibility meaning internal
1931 linkage. */
1932
1933 enum { VISIBILITY_ANON = VISIBILITY_INTERNAL+1 };
1934
1935 /* walk_tree helper function for type_visibility. */
1936
1937 static tree
min_vis_r(tree * tp,int * walk_subtrees,void * data)1938 min_vis_r (tree *tp, int *walk_subtrees, void *data)
1939 {
1940 int *vis_p = (int *)data;
1941 if (! TYPE_P (*tp))
1942 {
1943 *walk_subtrees = 0;
1944 }
1945 else if (TAGGED_TYPE_P (*tp)
1946 && !TREE_PUBLIC (TYPE_MAIN_DECL (*tp)))
1947 {
1948 *vis_p = VISIBILITY_ANON;
1949 return *tp;
1950 }
1951 else if (CLASS_TYPE_P (*tp)
1952 && CLASSTYPE_VISIBILITY (*tp) > *vis_p)
1953 *vis_p = CLASSTYPE_VISIBILITY (*tp);
1954 return NULL;
1955 }
1956
1957 /* Returns the visibility of TYPE, which is the minimum visibility of its
1958 component types. */
1959
1960 static int
type_visibility(tree type)1961 type_visibility (tree type)
1962 {
1963 int vis = VISIBILITY_DEFAULT;
1964 cp_walk_tree_without_duplicates (&type, min_vis_r, &vis);
1965 return vis;
1966 }
1967
1968 /* Limit the visibility of DECL to VISIBILITY, if not explicitly
1969 specified (or if VISIBILITY is static). If TMPL is true, this
1970 constraint is for a template argument, and takes precedence
1971 over explicitly-specified visibility on the template. */
1972
1973 static void
constrain_visibility(tree decl,int visibility,bool tmpl)1974 constrain_visibility (tree decl, int visibility, bool tmpl)
1975 {
1976 if (visibility == VISIBILITY_ANON)
1977 {
1978 /* extern "C" declarations aren't affected by the anonymous
1979 namespace. */
1980 if (!DECL_EXTERN_C_P (decl))
1981 {
1982 TREE_PUBLIC (decl) = 0;
1983 DECL_WEAK (decl) = 0;
1984 DECL_COMMON (decl) = 0;
1985 DECL_COMDAT_GROUP (decl) = NULL_TREE;
1986 DECL_INTERFACE_KNOWN (decl) = 1;
1987 if (DECL_LANG_SPECIFIC (decl))
1988 DECL_NOT_REALLY_EXTERN (decl) = 1;
1989 }
1990 }
1991 else if (visibility > DECL_VISIBILITY (decl)
1992 && (tmpl || !DECL_VISIBILITY_SPECIFIED (decl)))
1993 {
1994 DECL_VISIBILITY (decl) = (enum symbol_visibility) visibility;
1995 /* This visibility was not specified. */
1996 DECL_VISIBILITY_SPECIFIED (decl) = false;
1997 }
1998 }
1999
2000 /* Constrain the visibility of DECL based on the visibility of its template
2001 arguments. */
2002
2003 static void
constrain_visibility_for_template(tree decl,tree targs)2004 constrain_visibility_for_template (tree decl, tree targs)
2005 {
2006 /* If this is a template instantiation, check the innermost
2007 template args for visibility constraints. The outer template
2008 args are covered by the class check. */
2009 tree args = INNERMOST_TEMPLATE_ARGS (targs);
2010 int i;
2011 for (i = TREE_VEC_LENGTH (args); i > 0; --i)
2012 {
2013 int vis = 0;
2014
2015 tree arg = TREE_VEC_ELT (args, i-1);
2016 if (TYPE_P (arg))
2017 vis = type_visibility (arg);
2018 else if (TREE_TYPE (arg) && POINTER_TYPE_P (TREE_TYPE (arg)))
2019 {
2020 STRIP_NOPS (arg);
2021 if (TREE_CODE (arg) == ADDR_EXPR)
2022 arg = TREE_OPERAND (arg, 0);
2023 if (TREE_CODE (arg) == VAR_DECL
2024 || TREE_CODE (arg) == FUNCTION_DECL)
2025 {
2026 if (! TREE_PUBLIC (arg))
2027 vis = VISIBILITY_ANON;
2028 else
2029 vis = DECL_VISIBILITY (arg);
2030 }
2031 }
2032 if (vis)
2033 constrain_visibility (decl, vis, true);
2034 }
2035 }
2036
2037 /* Like c_determine_visibility, but with additional C++-specific
2038 behavior.
2039
2040 Function-scope entities can rely on the function's visibility because
2041 it is set in start_preparsed_function.
2042
2043 Class-scope entities cannot rely on the class's visibility until the end
2044 of the enclosing class definition.
2045
2046 Note that because namespaces have multiple independent definitions,
2047 namespace visibility is handled elsewhere using the #pragma visibility
2048 machinery rather than by decorating the namespace declaration.
2049
2050 The goal is for constraints from the type to give a diagnostic, and
2051 other constraints to be applied silently. */
2052
2053 void
determine_visibility(tree decl)2054 determine_visibility (tree decl)
2055 {
2056 tree class_type = NULL_TREE;
2057 bool use_template;
2058 bool orig_visibility_specified;
2059 enum symbol_visibility orig_visibility;
2060
2061 /* Remember that all decls get VISIBILITY_DEFAULT when built. */
2062
2063 /* Only relevant for names with external linkage. */
2064 if (!TREE_PUBLIC (decl))
2065 return;
2066
2067 /* Cloned constructors and destructors get the same visibility as
2068 the underlying function. That should be set up in
2069 maybe_clone_body. */
2070 gcc_assert (!DECL_CLONED_FUNCTION_P (decl));
2071
2072 orig_visibility_specified = DECL_VISIBILITY_SPECIFIED (decl);
2073 orig_visibility = DECL_VISIBILITY (decl);
2074
2075 if (TREE_CODE (decl) == TYPE_DECL)
2076 {
2077 if (CLASS_TYPE_P (TREE_TYPE (decl)))
2078 use_template = CLASSTYPE_USE_TEMPLATE (TREE_TYPE (decl));
2079 else if (TYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
2080 use_template = 1;
2081 else
2082 use_template = 0;
2083 }
2084 else if (DECL_LANG_SPECIFIC (decl))
2085 use_template = DECL_USE_TEMPLATE (decl);
2086 else
2087 use_template = 0;
2088
2089 /* If DECL is a member of a class, visibility specifiers on the
2090 class can influence the visibility of the DECL. */
2091 if (DECL_CLASS_SCOPE_P (decl))
2092 class_type = DECL_CONTEXT (decl);
2093 else
2094 {
2095 /* Not a class member. */
2096
2097 /* Virtual tables have DECL_CONTEXT set to their associated class,
2098 so they are automatically handled above. */
2099 gcc_assert (TREE_CODE (decl) != VAR_DECL
2100 || !DECL_VTABLE_OR_VTT_P (decl));
2101
2102 if (DECL_FUNCTION_SCOPE_P (decl) && ! DECL_VISIBILITY_SPECIFIED (decl))
2103 {
2104 /* Local statics and classes get the visibility of their
2105 containing function by default, except that
2106 -fvisibility-inlines-hidden doesn't affect them. */
2107 tree fn = DECL_CONTEXT (decl);
2108 if (DECL_VISIBILITY_SPECIFIED (fn))
2109 {
2110 DECL_VISIBILITY (decl) = DECL_VISIBILITY (fn);
2111 DECL_VISIBILITY_SPECIFIED (decl) =
2112 DECL_VISIBILITY_SPECIFIED (fn);
2113 }
2114 else
2115 {
2116 if (DECL_CLASS_SCOPE_P (fn))
2117 determine_visibility_from_class (decl, DECL_CONTEXT (fn));
2118 else if (determine_hidden_inline (fn))
2119 {
2120 DECL_VISIBILITY (decl) = default_visibility;
2121 DECL_VISIBILITY_SPECIFIED (decl) =
2122 visibility_options.inpragma;
2123 }
2124 else
2125 {
2126 DECL_VISIBILITY (decl) = DECL_VISIBILITY (fn);
2127 DECL_VISIBILITY_SPECIFIED (decl) =
2128 DECL_VISIBILITY_SPECIFIED (fn);
2129 }
2130 }
2131
2132 /* Local classes in templates have CLASSTYPE_USE_TEMPLATE set,
2133 but have no TEMPLATE_INFO, so don't try to check it. */
2134 use_template = 0;
2135 }
2136 else if (TREE_CODE (decl) == VAR_DECL && DECL_TINFO_P (decl)
2137 && flag_visibility_ms_compat)
2138 {
2139 /* Under -fvisibility-ms-compat, types are visible by default,
2140 even though their contents aren't. */
2141 tree underlying_type = TREE_TYPE (DECL_NAME (decl));
2142 int underlying_vis = type_visibility (underlying_type);
2143 if (underlying_vis == VISIBILITY_ANON
2144 || (CLASS_TYPE_P (underlying_type)
2145 && CLASSTYPE_VISIBILITY_SPECIFIED (underlying_type)))
2146 constrain_visibility (decl, underlying_vis, false);
2147 else
2148 DECL_VISIBILITY (decl) = VISIBILITY_DEFAULT;
2149 }
2150 else if (TREE_CODE (decl) == VAR_DECL && DECL_TINFO_P (decl))
2151 {
2152 /* tinfo visibility is based on the type it's for. */
2153 constrain_visibility
2154 (decl, type_visibility (TREE_TYPE (DECL_NAME (decl))), false);
2155
2156 /* Give the target a chance to override the visibility associated
2157 with DECL. */
2158 if (TREE_PUBLIC (decl)
2159 && !DECL_REALLY_EXTERN (decl)
2160 && CLASS_TYPE_P (TREE_TYPE (DECL_NAME (decl)))
2161 && !CLASSTYPE_VISIBILITY_SPECIFIED (TREE_TYPE (DECL_NAME (decl))))
2162 targetm.cxx.determine_class_data_visibility (decl);
2163 }
2164 else if (use_template)
2165 /* Template instantiations and specializations get visibility based
2166 on their template unless they override it with an attribute. */;
2167 else if (! DECL_VISIBILITY_SPECIFIED (decl))
2168 {
2169 if (determine_hidden_inline (decl))
2170 DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2171 else
2172 {
2173 /* Set default visibility to whatever the user supplied with
2174 #pragma GCC visibility or a namespace visibility attribute. */
2175 DECL_VISIBILITY (decl) = default_visibility;
2176 DECL_VISIBILITY_SPECIFIED (decl) = visibility_options.inpragma;
2177 }
2178 }
2179 }
2180
2181 if (use_template)
2182 {
2183 /* If the specialization doesn't specify visibility, use the
2184 visibility from the template. */
2185 tree tinfo = (TREE_CODE (decl) == TYPE_DECL
2186 ? TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
2187 : DECL_TEMPLATE_INFO (decl));
2188 tree args = TI_ARGS (tinfo);
2189 tree attribs = (TREE_CODE (decl) == TYPE_DECL
2190 ? TYPE_ATTRIBUTES (TREE_TYPE (decl))
2191 : DECL_ATTRIBUTES (decl));
2192
2193 if (args != error_mark_node)
2194 {
2195 tree pattern = DECL_TEMPLATE_RESULT (TI_TEMPLATE (tinfo));
2196
2197 if (!DECL_VISIBILITY_SPECIFIED (decl))
2198 {
2199 if (!DECL_VISIBILITY_SPECIFIED (pattern)
2200 && determine_hidden_inline (decl))
2201 DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2202 else
2203 {
2204 DECL_VISIBILITY (decl) = DECL_VISIBILITY (pattern);
2205 DECL_VISIBILITY_SPECIFIED (decl)
2206 = DECL_VISIBILITY_SPECIFIED (pattern);
2207 }
2208 }
2209
2210 if (args
2211 /* Template argument visibility outweighs #pragma or namespace
2212 visibility, but not an explicit attribute. */
2213 && !lookup_attribute ("visibility", attribs))
2214 {
2215 int depth = TMPL_ARGS_DEPTH (args);
2216 if (DECL_VISIBILITY_SPECIFIED (decl))
2217 {
2218 /* A class template member with explicit visibility
2219 overrides the class visibility, so we need to apply
2220 all the levels of template args directly. */
2221 int i;
2222 for (i = 1; i <= depth; ++i)
2223 {
2224 tree lev = TMPL_ARGS_LEVEL (args, i);
2225 constrain_visibility_for_template (decl, lev);
2226 }
2227 }
2228 else if (PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo)))
2229 /* Limit visibility based on its template arguments. */
2230 constrain_visibility_for_template (decl, args);
2231 }
2232 }
2233 }
2234
2235 if (class_type)
2236 determine_visibility_from_class (decl, class_type);
2237
2238 if (decl_anon_ns_mem_p (decl))
2239 /* Names in an anonymous namespace get internal linkage.
2240 This might change once we implement export. */
2241 constrain_visibility (decl, VISIBILITY_ANON, false);
2242 else if (TREE_CODE (decl) != TYPE_DECL)
2243 {
2244 /* Propagate anonymity from type to decl. */
2245 int tvis = type_visibility (TREE_TYPE (decl));
2246 if (tvis == VISIBILITY_ANON
2247 || ! DECL_VISIBILITY_SPECIFIED (decl))
2248 constrain_visibility (decl, tvis, false);
2249 }
2250 else if (no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/true))
2251 /* DR 757: A type without linkage shall not be used as the type of a
2252 variable or function with linkage, unless
2253 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
2254 o the variable or function is not used (3.2 [basic.def.odr]) or is
2255 defined in the same translation unit.
2256
2257 Since non-extern "C" decls need to be defined in the same
2258 translation unit, we can make the type internal. */
2259 constrain_visibility (decl, VISIBILITY_ANON, false);
2260
2261 /* If visibility changed and DECL already has DECL_RTL, ensure
2262 symbol flags are updated. */
2263 if ((DECL_VISIBILITY (decl) != orig_visibility
2264 || DECL_VISIBILITY_SPECIFIED (decl) != orig_visibility_specified)
2265 && ((TREE_CODE (decl) == VAR_DECL && TREE_STATIC (decl))
2266 || TREE_CODE (decl) == FUNCTION_DECL)
2267 && DECL_RTL_SET_P (decl))
2268 make_decl_rtl (decl);
2269 }
2270
2271 /* By default, static data members and function members receive
2272 the visibility of their containing class. */
2273
2274 static void
determine_visibility_from_class(tree decl,tree class_type)2275 determine_visibility_from_class (tree decl, tree class_type)
2276 {
2277 if (DECL_VISIBILITY_SPECIFIED (decl))
2278 return;
2279
2280 if (determine_hidden_inline (decl))
2281 DECL_VISIBILITY (decl) = VISIBILITY_HIDDEN;
2282 else
2283 {
2284 /* Default to the class visibility. */
2285 DECL_VISIBILITY (decl) = CLASSTYPE_VISIBILITY (class_type);
2286 DECL_VISIBILITY_SPECIFIED (decl)
2287 = CLASSTYPE_VISIBILITY_SPECIFIED (class_type);
2288 }
2289
2290 /* Give the target a chance to override the visibility associated
2291 with DECL. */
2292 if (TREE_CODE (decl) == VAR_DECL
2293 && (DECL_TINFO_P (decl)
2294 || (DECL_VTABLE_OR_VTT_P (decl)
2295 /* Construction virtual tables are not exported because
2296 they cannot be referred to from other object files;
2297 their name is not standardized by the ABI. */
2298 && !DECL_CONSTRUCTION_VTABLE_P (decl)))
2299 && TREE_PUBLIC (decl)
2300 && !DECL_REALLY_EXTERN (decl)
2301 && !CLASSTYPE_VISIBILITY_SPECIFIED (class_type))
2302 targetm.cxx.determine_class_data_visibility (decl);
2303 }
2304
2305 /* Returns true iff DECL is an inline that should get hidden visibility
2306 because of -fvisibility-inlines-hidden. */
2307
2308 static bool
determine_hidden_inline(tree decl)2309 determine_hidden_inline (tree decl)
2310 {
2311 return (visibility_options.inlines_hidden
2312 /* Don't do this for inline templates; specializations might not be
2313 inline, and we don't want them to inherit the hidden
2314 visibility. We'll set it here for all inline instantiations. */
2315 && !processing_template_decl
2316 && TREE_CODE (decl) == FUNCTION_DECL
2317 && DECL_DECLARED_INLINE_P (decl)
2318 && (! DECL_LANG_SPECIFIC (decl)
2319 || ! DECL_EXPLICIT_INSTANTIATION (decl)));
2320 }
2321
2322 /* Constrain the visibility of a class TYPE based on the visibility of its
2323 field types. Warn if any fields require lesser visibility. */
2324
2325 void
constrain_class_visibility(tree type)2326 constrain_class_visibility (tree type)
2327 {
2328 tree binfo;
2329 tree t;
2330 int i;
2331
2332 int vis = type_visibility (type);
2333
2334 if (vis == VISIBILITY_ANON
2335 || DECL_IN_SYSTEM_HEADER (TYPE_MAIN_DECL (type)))
2336 return;
2337
2338 /* Don't warn about visibility if the class has explicit visibility. */
2339 if (CLASSTYPE_VISIBILITY_SPECIFIED (type))
2340 vis = VISIBILITY_INTERNAL;
2341
2342 for (t = TYPE_FIELDS (type); t; t = DECL_CHAIN (t))
2343 if (TREE_CODE (t) == FIELD_DECL && TREE_TYPE (t) != error_mark_node)
2344 {
2345 tree ftype = strip_pointer_or_array_types (TREE_TYPE (t));
2346 int subvis = type_visibility (ftype);
2347
2348 if (subvis == VISIBILITY_ANON)
2349 {
2350 if (!in_main_input_context ())
2351 warning (0, "\
2352 %qT has a field %qD whose type uses the anonymous namespace",
2353 type, t);
2354 }
2355 else if (MAYBE_CLASS_TYPE_P (ftype)
2356 && vis < VISIBILITY_HIDDEN
2357 && subvis >= VISIBILITY_HIDDEN)
2358 warning (OPT_Wattributes, "\
2359 %qT declared with greater visibility than the type of its field %qD",
2360 type, t);
2361 }
2362
2363 binfo = TYPE_BINFO (type);
2364 for (i = 0; BINFO_BASE_ITERATE (binfo, i, t); ++i)
2365 {
2366 int subvis = type_visibility (TREE_TYPE (t));
2367
2368 if (subvis == VISIBILITY_ANON)
2369 {
2370 if (!in_main_input_context())
2371 warning (0, "\
2372 %qT has a base %qT whose type uses the anonymous namespace",
2373 type, TREE_TYPE (t));
2374 }
2375 else if (vis < VISIBILITY_HIDDEN
2376 && subvis >= VISIBILITY_HIDDEN)
2377 warning (OPT_Wattributes, "\
2378 %qT declared with greater visibility than its base %qT",
2379 type, TREE_TYPE (t));
2380 }
2381 }
2382
2383 /* DECL is a FUNCTION_DECL or VAR_DECL. If the object file linkage
2384 for DECL has not already been determined, do so now by setting
2385 DECL_EXTERNAL, DECL_COMDAT and other related flags. Until this
2386 function is called entities with vague linkage whose definitions
2387 are available must have TREE_PUBLIC set.
2388
2389 If this function decides to place DECL in COMDAT, it will set
2390 appropriate flags -- but will not clear DECL_EXTERNAL. It is up to
2391 the caller to decide whether or not to clear DECL_EXTERNAL. Some
2392 callers defer that decision until it is clear that DECL is actually
2393 required. */
2394
2395 void
import_export_decl(tree decl)2396 import_export_decl (tree decl)
2397 {
2398 int emit_p;
2399 bool comdat_p;
2400 bool import_p;
2401 tree class_type = NULL_TREE;
2402
2403 if (DECL_INTERFACE_KNOWN (decl))
2404 return;
2405
2406 /* We cannot determine what linkage to give to an entity with vague
2407 linkage until the end of the file. For example, a virtual table
2408 for a class will be defined if and only if the key method is
2409 defined in this translation unit. As a further example, consider
2410 that when compiling a translation unit that uses PCH file with
2411 "-frepo" it would be incorrect to make decisions about what
2412 entities to emit when building the PCH; those decisions must be
2413 delayed until the repository information has been processed. */
2414 gcc_assert (at_eof);
2415 /* Object file linkage for explicit instantiations is handled in
2416 mark_decl_instantiated. For static variables in functions with
2417 vague linkage, maybe_commonize_var is used.
2418
2419 Therefore, the only declarations that should be provided to this
2420 function are those with external linkage that are:
2421
2422 * implicit instantiations of function templates
2423
2424 * inline function
2425
2426 * implicit instantiations of static data members of class
2427 templates
2428
2429 * virtual tables
2430
2431 * typeinfo objects
2432
2433 Furthermore, all entities that reach this point must have a
2434 definition available in this translation unit.
2435
2436 The following assertions check these conditions. */
2437 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
2438 || TREE_CODE (decl) == VAR_DECL);
2439 /* Any code that creates entities with TREE_PUBLIC cleared should
2440 also set DECL_INTERFACE_KNOWN. */
2441 gcc_assert (TREE_PUBLIC (decl));
2442 if (TREE_CODE (decl) == FUNCTION_DECL)
2443 gcc_assert (DECL_IMPLICIT_INSTANTIATION (decl)
2444 || DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (decl)
2445 || DECL_DECLARED_INLINE_P (decl));
2446 else
2447 gcc_assert (DECL_IMPLICIT_INSTANTIATION (decl)
2448 || DECL_VTABLE_OR_VTT_P (decl)
2449 || DECL_TINFO_P (decl));
2450 /* Check that a definition of DECL is available in this translation
2451 unit. */
2452 gcc_assert (!DECL_REALLY_EXTERN (decl));
2453
2454 /* Assume that DECL will not have COMDAT linkage. */
2455 comdat_p = false;
2456 /* Assume that DECL will not be imported into this translation
2457 unit. */
2458 import_p = false;
2459
2460 /* See if the repository tells us whether or not to emit DECL in
2461 this translation unit. */
2462 emit_p = repo_emit_p (decl);
2463 if (emit_p == 0)
2464 import_p = true;
2465 else if (emit_p == 1)
2466 {
2467 /* The repository indicates that this entity should be defined
2468 here. Make sure the back end honors that request. */
2469 if (TREE_CODE (decl) == VAR_DECL)
2470 mark_needed (decl);
2471 else if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (decl)
2472 || DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (decl))
2473 {
2474 tree clone;
2475 FOR_EACH_CLONE (clone, decl)
2476 mark_needed (clone);
2477 }
2478 else
2479 mark_needed (decl);
2480 /* Output the definition as an ordinary strong definition. */
2481 DECL_EXTERNAL (decl) = 0;
2482 DECL_INTERFACE_KNOWN (decl) = 1;
2483 return;
2484 }
2485
2486 if (import_p)
2487 /* We have already decided what to do with this DECL; there is no
2488 need to check anything further. */
2489 ;
2490 else if (TREE_CODE (decl) == VAR_DECL && DECL_VTABLE_OR_VTT_P (decl))
2491 {
2492 class_type = DECL_CONTEXT (decl);
2493 import_export_class (class_type);
2494 if (TYPE_FOR_JAVA (class_type))
2495 import_p = true;
2496 else if (CLASSTYPE_INTERFACE_KNOWN (class_type)
2497 && CLASSTYPE_INTERFACE_ONLY (class_type))
2498 import_p = true;
2499 else if ((!flag_weak || TARGET_WEAK_NOT_IN_ARCHIVE_TOC)
2500 && !CLASSTYPE_USE_TEMPLATE (class_type)
2501 && CLASSTYPE_KEY_METHOD (class_type)
2502 && !DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (class_type)))
2503 /* The ABI requires that all virtual tables be emitted with
2504 COMDAT linkage. However, on systems where COMDAT symbols
2505 don't show up in the table of contents for a static
2506 archive, or on systems without weak symbols (where we
2507 approximate COMDAT linkage by using internal linkage), the
2508 linker will report errors about undefined symbols because
2509 it will not see the virtual table definition. Therefore,
2510 in the case that we know that the virtual table will be
2511 emitted in only one translation unit, we make the virtual
2512 table an ordinary definition with external linkage. */
2513 DECL_EXTERNAL (decl) = 0;
2514 else if (CLASSTYPE_INTERFACE_KNOWN (class_type))
2515 {
2516 /* CLASS_TYPE is being exported from this translation unit,
2517 so DECL should be defined here. */
2518 if (!flag_weak && CLASSTYPE_EXPLICIT_INSTANTIATION (class_type))
2519 /* If a class is declared in a header with the "extern
2520 template" extension, then it will not be instantiated,
2521 even in translation units that would normally require
2522 it. Often such classes are explicitly instantiated in
2523 one translation unit. Therefore, the explicit
2524 instantiation must be made visible to other translation
2525 units. */
2526 DECL_EXTERNAL (decl) = 0;
2527 else
2528 {
2529 /* The generic C++ ABI says that class data is always
2530 COMDAT, even if there is a key function. Some
2531 variants (e.g., the ARM EABI) says that class data
2532 only has COMDAT linkage if the class data might be
2533 emitted in more than one translation unit. When the
2534 key method can be inline and is inline, we still have
2535 to arrange for comdat even though
2536 class_data_always_comdat is false. */
2537 if (!CLASSTYPE_KEY_METHOD (class_type)
2538 || DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (class_type))
2539 || targetm.cxx.class_data_always_comdat ())
2540 {
2541 /* The ABI requires COMDAT linkage. Normally, we
2542 only emit COMDAT things when they are needed;
2543 make sure that we realize that this entity is
2544 indeed needed. */
2545 comdat_p = true;
2546 mark_needed (decl);
2547 }
2548 }
2549 }
2550 else if (!flag_implicit_templates
2551 && CLASSTYPE_IMPLICIT_INSTANTIATION (class_type))
2552 import_p = true;
2553 else
2554 comdat_p = true;
2555 }
2556 else if (TREE_CODE (decl) == VAR_DECL && DECL_TINFO_P (decl))
2557 {
2558 tree type = TREE_TYPE (DECL_NAME (decl));
2559 if (CLASS_TYPE_P (type))
2560 {
2561 class_type = type;
2562 import_export_class (type);
2563 if (CLASSTYPE_INTERFACE_KNOWN (type)
2564 && TYPE_POLYMORPHIC_P (type)
2565 && CLASSTYPE_INTERFACE_ONLY (type)
2566 /* If -fno-rtti was specified, then we cannot be sure
2567 that RTTI information will be emitted with the
2568 virtual table of the class, so we must emit it
2569 wherever it is used. */
2570 && flag_rtti)
2571 import_p = true;
2572 else
2573 {
2574 if (CLASSTYPE_INTERFACE_KNOWN (type)
2575 && !CLASSTYPE_INTERFACE_ONLY (type))
2576 {
2577 comdat_p = (targetm.cxx.class_data_always_comdat ()
2578 || (CLASSTYPE_KEY_METHOD (type)
2579 && DECL_DECLARED_INLINE_P (CLASSTYPE_KEY_METHOD (type))));
2580 mark_needed (decl);
2581 if (!flag_weak)
2582 {
2583 comdat_p = false;
2584 DECL_EXTERNAL (decl) = 0;
2585 }
2586 }
2587 else
2588 comdat_p = true;
2589 }
2590 }
2591 else
2592 comdat_p = true;
2593 }
2594 else if (DECL_TEMPLATE_INSTANTIATION (decl)
2595 || DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (decl))
2596 {
2597 /* DECL is an implicit instantiation of a function or static
2598 data member. */
2599 if ((flag_implicit_templates
2600 && !flag_use_repository)
2601 || (flag_implicit_inline_templates
2602 && TREE_CODE (decl) == FUNCTION_DECL
2603 && DECL_DECLARED_INLINE_P (decl)))
2604 comdat_p = true;
2605 else
2606 /* If we are not implicitly generating templates, then mark
2607 this entity as undefined in this translation unit. */
2608 import_p = true;
2609 }
2610 else if (DECL_FUNCTION_MEMBER_P (decl))
2611 {
2612 if (!DECL_DECLARED_INLINE_P (decl))
2613 {
2614 tree ctype = DECL_CONTEXT (decl);
2615 import_export_class (ctype);
2616 if (CLASSTYPE_INTERFACE_KNOWN (ctype))
2617 {
2618 DECL_NOT_REALLY_EXTERN (decl)
2619 = ! (CLASSTYPE_INTERFACE_ONLY (ctype)
2620 || (DECL_DECLARED_INLINE_P (decl)
2621 && ! flag_implement_inlines
2622 && !DECL_VINDEX (decl)));
2623
2624 if (!DECL_NOT_REALLY_EXTERN (decl))
2625 DECL_EXTERNAL (decl) = 1;
2626
2627 /* Always make artificials weak. */
2628 if (DECL_ARTIFICIAL (decl) && flag_weak)
2629 comdat_p = true;
2630 else
2631 maybe_make_one_only (decl);
2632 }
2633 }
2634 else
2635 comdat_p = true;
2636 }
2637 else
2638 comdat_p = true;
2639
2640 if (import_p)
2641 {
2642 /* If we are importing DECL into this translation unit, mark is
2643 an undefined here. */
2644 DECL_EXTERNAL (decl) = 1;
2645 DECL_NOT_REALLY_EXTERN (decl) = 0;
2646 }
2647 else if (comdat_p)
2648 {
2649 /* If we decided to put DECL in COMDAT, mark it accordingly at
2650 this point. */
2651 comdat_linkage (decl);
2652 }
2653
2654 DECL_INTERFACE_KNOWN (decl) = 1;
2655 }
2656
2657 /* Return an expression that performs the destruction of DECL, which
2658 must be a VAR_DECL whose type has a non-trivial destructor, or is
2659 an array whose (innermost) elements have a non-trivial destructor. */
2660
2661 tree
build_cleanup(tree decl)2662 build_cleanup (tree decl)
2663 {
2664 tree temp;
2665 tree type = TREE_TYPE (decl);
2666
2667 /* This function should only be called for declarations that really
2668 require cleanups. */
2669 gcc_assert (!TYPE_HAS_TRIVIAL_DESTRUCTOR (type));
2670
2671 /* Treat all objects with destructors as used; the destructor may do
2672 something substantive. */
2673 mark_used (decl);
2674
2675 if (TREE_CODE (type) == ARRAY_TYPE)
2676 temp = decl;
2677 else
2678 temp = build_address (decl);
2679 temp = build_delete (TREE_TYPE (temp), temp,
2680 sfk_complete_destructor,
2681 LOOKUP_NORMAL|LOOKUP_NONVIRTUAL|LOOKUP_DESTRUCTOR, 0,
2682 tf_warning_or_error);
2683 return temp;
2684 }
2685
2686 /* Returns the initialization guard variable for the variable DECL,
2687 which has static storage duration. */
2688
2689 tree
get_guard(tree decl)2690 get_guard (tree decl)
2691 {
2692 tree sname;
2693 tree guard;
2694
2695 sname = mangle_guard_variable (decl);
2696 guard = IDENTIFIER_GLOBAL_VALUE (sname);
2697 if (! guard)
2698 {
2699 tree guard_type;
2700
2701 /* We use a type that is big enough to contain a mutex as well
2702 as an integer counter. */
2703 guard_type = targetm.cxx.guard_type ();
2704 guard = build_decl (DECL_SOURCE_LOCATION (decl),
2705 VAR_DECL, sname, guard_type);
2706
2707 /* The guard should have the same linkage as what it guards. */
2708 TREE_PUBLIC (guard) = TREE_PUBLIC (decl);
2709 TREE_STATIC (guard) = TREE_STATIC (decl);
2710 DECL_COMMON (guard) = DECL_COMMON (decl);
2711 DECL_COMDAT (guard) = DECL_COMDAT (decl);
2712 DECL_TLS_MODEL (guard) = DECL_TLS_MODEL (decl);
2713 if (DECL_ONE_ONLY (decl))
2714 make_decl_one_only (guard, cxx_comdat_group (guard));
2715 if (TREE_PUBLIC (decl))
2716 DECL_WEAK (guard) = DECL_WEAK (decl);
2717 DECL_VISIBILITY (guard) = DECL_VISIBILITY (decl);
2718 DECL_VISIBILITY_SPECIFIED (guard) = DECL_VISIBILITY_SPECIFIED (decl);
2719
2720 DECL_ARTIFICIAL (guard) = 1;
2721 DECL_IGNORED_P (guard) = 1;
2722 TREE_USED (guard) = 1;
2723 pushdecl_top_level_and_finish (guard, NULL_TREE);
2724 }
2725 return guard;
2726 }
2727
2728 /* Return those bits of the GUARD variable that should be set when the
2729 guarded entity is actually initialized. */
2730
2731 static tree
get_guard_bits(tree guard)2732 get_guard_bits (tree guard)
2733 {
2734 if (!targetm.cxx.guard_mask_bit ())
2735 {
2736 /* We only set the first byte of the guard, in order to leave room
2737 for a mutex in the high-order bits. */
2738 guard = build1 (ADDR_EXPR,
2739 build_pointer_type (TREE_TYPE (guard)),
2740 guard);
2741 guard = build1 (NOP_EXPR,
2742 build_pointer_type (char_type_node),
2743 guard);
2744 guard = build1 (INDIRECT_REF, char_type_node, guard);
2745 }
2746
2747 return guard;
2748 }
2749
2750 /* Return an expression which determines whether or not the GUARD
2751 variable has already been initialized. */
2752
2753 tree
get_guard_cond(tree guard)2754 get_guard_cond (tree guard)
2755 {
2756 tree guard_value;
2757
2758 /* Check to see if the GUARD is zero. */
2759 guard = get_guard_bits (guard);
2760
2761 /* Mask off all but the low bit. */
2762 if (targetm.cxx.guard_mask_bit ())
2763 {
2764 guard_value = integer_one_node;
2765 if (!same_type_p (TREE_TYPE (guard_value), TREE_TYPE (guard)))
2766 guard_value = convert (TREE_TYPE (guard), guard_value);
2767 guard = cp_build_binary_op (input_location,
2768 BIT_AND_EXPR, guard, guard_value,
2769 tf_warning_or_error);
2770 }
2771
2772 guard_value = integer_zero_node;
2773 if (!same_type_p (TREE_TYPE (guard_value), TREE_TYPE (guard)))
2774 guard_value = convert (TREE_TYPE (guard), guard_value);
2775 return cp_build_binary_op (input_location,
2776 EQ_EXPR, guard, guard_value,
2777 tf_warning_or_error);
2778 }
2779
2780 /* Return an expression which sets the GUARD variable, indicating that
2781 the variable being guarded has been initialized. */
2782
2783 tree
set_guard(tree guard)2784 set_guard (tree guard)
2785 {
2786 tree guard_init;
2787
2788 /* Set the GUARD to one. */
2789 guard = get_guard_bits (guard);
2790 guard_init = integer_one_node;
2791 if (!same_type_p (TREE_TYPE (guard_init), TREE_TYPE (guard)))
2792 guard_init = convert (TREE_TYPE (guard), guard_init);
2793 return cp_build_modify_expr (guard, NOP_EXPR, guard_init,
2794 tf_warning_or_error);
2795 }
2796
2797 /* Returns true iff we can tell that VAR does not have a dynamic
2798 initializer. */
2799
2800 static bool
var_defined_without_dynamic_init(tree var)2801 var_defined_without_dynamic_init (tree var)
2802 {
2803 /* If it's defined in another TU, we can't tell. */
2804 if (DECL_EXTERNAL (var))
2805 return false;
2806 /* If it has a non-trivial destructor, registering the destructor
2807 counts as dynamic initialization. */
2808 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (TREE_TYPE (var)))
2809 return false;
2810 /* If it's in this TU, its initializer has been processed. */
2811 gcc_assert (DECL_INITIALIZED_P (var));
2812 /* If it has no initializer or a constant one, it's not dynamic. */
2813 return (!DECL_NONTRIVIALLY_INITIALIZED_P (var)
2814 || DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var));
2815 }
2816
2817 /* Returns true iff VAR is a variable that needs uses to be
2818 wrapped for possible dynamic initialization. */
2819
2820 static bool
var_needs_tls_wrapper(tree var)2821 var_needs_tls_wrapper (tree var)
2822 {
2823 return (!error_operand_p (var)
2824 && DECL_THREAD_LOCAL_P (var)
2825 && !DECL_GNU_TLS_P (var)
2826 && !DECL_FUNCTION_SCOPE_P (var)
2827 && !var_defined_without_dynamic_init (var));
2828 }
2829
2830 /* Get the FUNCTION_DECL for the shared TLS init function for this
2831 translation unit. */
2832
2833 static tree
get_local_tls_init_fn(void)2834 get_local_tls_init_fn (void)
2835 {
2836 tree sname = get_identifier ("__tls_init");
2837 tree fn = IDENTIFIER_GLOBAL_VALUE (sname);
2838 if (!fn)
2839 {
2840 fn = build_lang_decl (FUNCTION_DECL, sname,
2841 build_function_type (void_type_node,
2842 void_list_node));
2843 SET_DECL_LANGUAGE (fn, lang_c);
2844 TREE_PUBLIC (fn) = false;
2845 DECL_ARTIFICIAL (fn) = true;
2846 mark_used (fn);
2847 SET_IDENTIFIER_GLOBAL_VALUE (sname, fn);
2848 }
2849 return fn;
2850 }
2851
2852 /* Get a FUNCTION_DECL for the init function for the thread_local
2853 variable VAR. The init function will be an alias to the function
2854 that initializes all the non-local TLS variables in the translation
2855 unit. The init function is only used by the wrapper function. */
2856
2857 static tree
get_tls_init_fn(tree var)2858 get_tls_init_fn (tree var)
2859 {
2860 /* Only C++11 TLS vars need this init fn. */
2861 if (!var_needs_tls_wrapper (var))
2862 return NULL_TREE;
2863
2864 /* If -fno-extern-tls-init, assume that we don't need to call
2865 a tls init function for a variable defined in another TU. */
2866 if (!flag_extern_tls_init && DECL_EXTERNAL (var))
2867 return NULL_TREE;
2868
2869 #ifdef ASM_OUTPUT_DEF
2870 /* If the variable is internal, or if we can't generate aliases,
2871 call the local init function directly. */
2872 if (!TREE_PUBLIC (var))
2873 #endif
2874 return get_local_tls_init_fn ();
2875
2876 tree sname = mangle_tls_init_fn (var);
2877 tree fn = IDENTIFIER_GLOBAL_VALUE (sname);
2878 if (!fn)
2879 {
2880 fn = build_lang_decl (FUNCTION_DECL, sname,
2881 build_function_type (void_type_node,
2882 void_list_node));
2883 SET_DECL_LANGUAGE (fn, lang_c);
2884 TREE_PUBLIC (fn) = TREE_PUBLIC (var);
2885 DECL_ARTIFICIAL (fn) = true;
2886 DECL_COMDAT (fn) = DECL_COMDAT (var);
2887 DECL_EXTERNAL (fn) = true;
2888 if (DECL_ONE_ONLY (var))
2889 make_decl_one_only (fn, cxx_comdat_group (fn));
2890 if (TREE_PUBLIC (var))
2891 {
2892 tree obtype = strip_array_types (non_reference (TREE_TYPE (var)));
2893 /* If the variable is defined somewhere else and might have static
2894 initialization, make the init function a weak reference. */
2895 if ((!TYPE_NEEDS_CONSTRUCTING (obtype)
2896 || TYPE_HAS_CONSTEXPR_CTOR (obtype))
2897 && TYPE_HAS_TRIVIAL_DESTRUCTOR (obtype)
2898 && DECL_EXTERNAL (var))
2899 declare_weak (fn);
2900 else
2901 DECL_WEAK (fn) = DECL_WEAK (var);
2902 }
2903 DECL_VISIBILITY (fn) = DECL_VISIBILITY (var);
2904 DECL_VISIBILITY_SPECIFIED (fn) = DECL_VISIBILITY_SPECIFIED (var);
2905 DECL_DLLIMPORT_P (fn) = DECL_DLLIMPORT_P (var);
2906 DECL_IGNORED_P (fn) = 1;
2907 mark_used (fn);
2908
2909 DECL_BEFRIENDING_CLASSES (fn) = var;
2910
2911 SET_IDENTIFIER_GLOBAL_VALUE (sname, fn);
2912 }
2913 return fn;
2914 }
2915
2916 /* Get a FUNCTION_DECL for the init wrapper function for the thread_local
2917 variable VAR. The wrapper function calls the init function (if any) for
2918 VAR and then returns a reference to VAR. The wrapper function is used
2919 in place of VAR everywhere VAR is mentioned. */
2920
2921 tree
get_tls_wrapper_fn(tree var)2922 get_tls_wrapper_fn (tree var)
2923 {
2924 /* Only C++11 TLS vars need this wrapper fn. */
2925 if (!var_needs_tls_wrapper (var))
2926 return NULL_TREE;
2927
2928 tree sname = mangle_tls_wrapper_fn (var);
2929 tree fn = IDENTIFIER_GLOBAL_VALUE (sname);
2930 if (!fn)
2931 {
2932 /* A named rvalue reference is an lvalue, so the wrapper should
2933 always return an lvalue reference. */
2934 tree type = non_reference (TREE_TYPE (var));
2935 type = build_reference_type (type);
2936 tree fntype = build_function_type (type, void_list_node);
2937 fn = build_lang_decl (FUNCTION_DECL, sname, fntype);
2938 SET_DECL_LANGUAGE (fn, lang_c);
2939 TREE_PUBLIC (fn) = TREE_PUBLIC (var);
2940 DECL_ARTIFICIAL (fn) = true;
2941 DECL_IGNORED_P (fn) = 1;
2942 /* The wrapper is inline and emitted everywhere var is used. */
2943 DECL_DECLARED_INLINE_P (fn) = true;
2944 if (TREE_PUBLIC (var))
2945 {
2946 comdat_linkage (fn);
2947 #ifdef HAVE_GAS_HIDDEN
2948 /* Make the wrapper bind locally; there's no reason to share
2949 the wrapper between multiple shared objects. */
2950 DECL_VISIBILITY (fn) = VISIBILITY_INTERNAL;
2951 DECL_VISIBILITY_SPECIFIED (fn) = true;
2952 #endif
2953 }
2954 if (!TREE_PUBLIC (fn))
2955 DECL_INTERFACE_KNOWN (fn) = true;
2956 mark_used (fn);
2957 note_vague_linkage_fn (fn);
2958
2959 #if 0
2960 /* We want CSE to commonize calls to the wrapper, but marking it as
2961 pure is unsafe since it has side-effects. I guess we need a new
2962 ECF flag even weaker than ECF_PURE. FIXME! */
2963 DECL_PURE_P (fn) = true;
2964 #endif
2965
2966 DECL_BEFRIENDING_CLASSES (fn) = var;
2967
2968 SET_IDENTIFIER_GLOBAL_VALUE (sname, fn);
2969 }
2970 return fn;
2971 }
2972
2973 /* At EOF, generate the definition for the TLS wrapper function FN:
2974
2975 T& var_wrapper() {
2976 if (init_fn) init_fn();
2977 return var;
2978 } */
2979
2980 static void
generate_tls_wrapper(tree fn)2981 generate_tls_wrapper (tree fn)
2982 {
2983 tree var = DECL_BEFRIENDING_CLASSES (fn);
2984
2985 start_preparsed_function (fn, NULL_TREE, SF_DEFAULT | SF_PRE_PARSED);
2986 tree body = begin_function_body ();
2987 /* Only call the init fn if there might be one. */
2988 if (tree init_fn = get_tls_init_fn (var))
2989 {
2990 tree if_stmt = NULL_TREE;
2991 /* If init_fn is a weakref, make sure it exists before calling. */
2992 if (lookup_attribute ("weak", DECL_ATTRIBUTES (init_fn)))
2993 {
2994 if_stmt = begin_if_stmt ();
2995 tree addr = cp_build_addr_expr (init_fn, tf_warning_or_error);
2996 tree cond = cp_build_binary_op (DECL_SOURCE_LOCATION (var),
2997 NE_EXPR, addr, nullptr_node,
2998 tf_warning_or_error);
2999 finish_if_stmt_cond (cond, if_stmt);
3000 }
3001 finish_expr_stmt (build_cxx_call
3002 (init_fn, 0, NULL, tf_warning_or_error));
3003 if (if_stmt)
3004 {
3005 finish_then_clause (if_stmt);
3006 finish_if_stmt (if_stmt);
3007 }
3008 }
3009 else
3010 /* If there's no initialization, the wrapper is a constant function. */
3011 TREE_READONLY (fn) = true;
3012 finish_return_stmt (convert_from_reference (var));
3013 finish_function_body (body);
3014 expand_or_defer_fn (finish_function (0));
3015 }
3016
3017 /* Start the process of running a particular set of global constructors
3018 or destructors. Subroutine of do_[cd]tors. */
3019
3020 static tree
start_objects(int method_type,int initp)3021 start_objects (int method_type, int initp)
3022 {
3023 tree body;
3024 tree fndecl;
3025 char type[14];
3026
3027 /* Make ctor or dtor function. METHOD_TYPE may be 'I' or 'D'. */
3028
3029 if (initp != DEFAULT_INIT_PRIORITY)
3030 {
3031 char joiner;
3032
3033 #ifdef JOINER
3034 joiner = JOINER;
3035 #else
3036 joiner = '_';
3037 #endif
3038
3039 sprintf (type, "sub_%c%c%.5u", method_type, joiner, initp);
3040 }
3041 else
3042 sprintf (type, "sub_%c", method_type);
3043
3044 fndecl = build_lang_decl (FUNCTION_DECL,
3045 get_file_function_name (type),
3046 build_function_type_list (void_type_node,
3047 NULL_TREE));
3048 start_preparsed_function (fndecl, /*attrs=*/NULL_TREE, SF_PRE_PARSED);
3049
3050 TREE_PUBLIC (current_function_decl) = 0;
3051
3052 /* Mark as artificial because it's not explicitly in the user's
3053 source code. */
3054 DECL_ARTIFICIAL (current_function_decl) = 1;
3055
3056 /* Mark this declaration as used to avoid spurious warnings. */
3057 TREE_USED (current_function_decl) = 1;
3058
3059 /* Mark this function as a global constructor or destructor. */
3060 if (method_type == 'I')
3061 DECL_GLOBAL_CTOR_P (current_function_decl) = 1;
3062 else
3063 DECL_GLOBAL_DTOR_P (current_function_decl) = 1;
3064
3065 body = begin_compound_stmt (BCS_FN_BODY);
3066
3067 return body;
3068 }
3069
3070 /* Finish the process of running a particular set of global constructors
3071 or destructors. Subroutine of do_[cd]tors. */
3072
3073 static void
finish_objects(int method_type,int initp,tree body)3074 finish_objects (int method_type, int initp, tree body)
3075 {
3076 tree fn;
3077
3078 /* Finish up. */
3079 finish_compound_stmt (body);
3080 fn = finish_function (0);
3081
3082 if (method_type == 'I')
3083 {
3084 DECL_STATIC_CONSTRUCTOR (fn) = 1;
3085 decl_init_priority_insert (fn, initp);
3086 }
3087 else
3088 {
3089 DECL_STATIC_DESTRUCTOR (fn) = 1;
3090 decl_fini_priority_insert (fn, initp);
3091 }
3092
3093 expand_or_defer_fn (fn);
3094 }
3095
3096 /* The names of the parameters to the function created to handle
3097 initializations and destructions for objects with static storage
3098 duration. */
3099 #define INITIALIZE_P_IDENTIFIER "__initialize_p"
3100 #define PRIORITY_IDENTIFIER "__priority"
3101
3102 /* The name of the function we create to handle initializations and
3103 destructions for objects with static storage duration. */
3104 #define SSDF_IDENTIFIER "__static_initialization_and_destruction"
3105
3106 /* The declaration for the __INITIALIZE_P argument. */
3107 static GTY(()) tree initialize_p_decl;
3108
3109 /* The declaration for the __PRIORITY argument. */
3110 static GTY(()) tree priority_decl;
3111
3112 /* The declaration for the static storage duration function. */
3113 static GTY(()) tree ssdf_decl;
3114
3115 /* All the static storage duration functions created in this
3116 translation unit. */
3117 static GTY(()) vec<tree, va_gc> *ssdf_decls;
3118
3119 /* A map from priority levels to information about that priority
3120 level. There may be many such levels, so efficient lookup is
3121 important. */
3122 static splay_tree priority_info_map;
3123
3124 /* Begins the generation of the function that will handle all
3125 initialization and destruction of objects with static storage
3126 duration. The function generated takes two parameters of type
3127 `int': __INITIALIZE_P and __PRIORITY. If __INITIALIZE_P is
3128 nonzero, it performs initializations. Otherwise, it performs
3129 destructions. It only performs those initializations or
3130 destructions with the indicated __PRIORITY. The generated function
3131 returns no value.
3132
3133 It is assumed that this function will only be called once per
3134 translation unit. */
3135
3136 static tree
start_static_storage_duration_function(unsigned count)3137 start_static_storage_duration_function (unsigned count)
3138 {
3139 tree type;
3140 tree body;
3141 char id[sizeof (SSDF_IDENTIFIER) + 1 /* '\0' */ + 32];
3142
3143 /* Create the identifier for this function. It will be of the form
3144 SSDF_IDENTIFIER_<number>. */
3145 sprintf (id, "%s_%u", SSDF_IDENTIFIER, count);
3146
3147 type = build_function_type_list (void_type_node,
3148 integer_type_node, integer_type_node,
3149 NULL_TREE);
3150
3151 /* Create the FUNCTION_DECL itself. */
3152 ssdf_decl = build_lang_decl (FUNCTION_DECL,
3153 get_identifier (id),
3154 type);
3155 TREE_PUBLIC (ssdf_decl) = 0;
3156 DECL_ARTIFICIAL (ssdf_decl) = 1;
3157
3158 /* Put this function in the list of functions to be called from the
3159 static constructors and destructors. */
3160 if (!ssdf_decls)
3161 {
3162 vec_alloc (ssdf_decls, 32);
3163
3164 /* Take this opportunity to initialize the map from priority
3165 numbers to information about that priority level. */
3166 priority_info_map = splay_tree_new (splay_tree_compare_ints,
3167 /*delete_key_fn=*/0,
3168 /*delete_value_fn=*/
3169 (splay_tree_delete_value_fn) &free);
3170
3171 /* We always need to generate functions for the
3172 DEFAULT_INIT_PRIORITY so enter it now. That way when we walk
3173 priorities later, we'll be sure to find the
3174 DEFAULT_INIT_PRIORITY. */
3175 get_priority_info (DEFAULT_INIT_PRIORITY);
3176 }
3177
3178 vec_safe_push (ssdf_decls, ssdf_decl);
3179
3180 /* Create the argument list. */
3181 initialize_p_decl = cp_build_parm_decl
3182 (get_identifier (INITIALIZE_P_IDENTIFIER), integer_type_node);
3183 DECL_CONTEXT (initialize_p_decl) = ssdf_decl;
3184 TREE_USED (initialize_p_decl) = 1;
3185 priority_decl = cp_build_parm_decl
3186 (get_identifier (PRIORITY_IDENTIFIER), integer_type_node);
3187 DECL_CONTEXT (priority_decl) = ssdf_decl;
3188 TREE_USED (priority_decl) = 1;
3189
3190 DECL_CHAIN (initialize_p_decl) = priority_decl;
3191 DECL_ARGUMENTS (ssdf_decl) = initialize_p_decl;
3192
3193 /* Put the function in the global scope. */
3194 pushdecl (ssdf_decl);
3195
3196 /* Start the function itself. This is equivalent to declaring the
3197 function as:
3198
3199 static void __ssdf (int __initialize_p, init __priority_p);
3200
3201 It is static because we only need to call this function from the
3202 various constructor and destructor functions for this module. */
3203 start_preparsed_function (ssdf_decl,
3204 /*attrs=*/NULL_TREE,
3205 SF_PRE_PARSED);
3206
3207 /* Set up the scope of the outermost block in the function. */
3208 body = begin_compound_stmt (BCS_FN_BODY);
3209
3210 return body;
3211 }
3212
3213 /* Finish the generation of the function which performs initialization
3214 and destruction of objects with static storage duration. After
3215 this point, no more such objects can be created. */
3216
3217 static void
finish_static_storage_duration_function(tree body)3218 finish_static_storage_duration_function (tree body)
3219 {
3220 /* Close out the function. */
3221 finish_compound_stmt (body);
3222 expand_or_defer_fn (finish_function (0));
3223 }
3224
3225 /* Return the information about the indicated PRIORITY level. If no
3226 code to handle this level has yet been generated, generate the
3227 appropriate prologue. */
3228
3229 static priority_info
get_priority_info(int priority)3230 get_priority_info (int priority)
3231 {
3232 priority_info pi;
3233 splay_tree_node n;
3234
3235 n = splay_tree_lookup (priority_info_map,
3236 (splay_tree_key) priority);
3237 if (!n)
3238 {
3239 /* Create a new priority information structure, and insert it
3240 into the map. */
3241 pi = XNEW (struct priority_info_s);
3242 pi->initializations_p = 0;
3243 pi->destructions_p = 0;
3244 splay_tree_insert (priority_info_map,
3245 (splay_tree_key) priority,
3246 (splay_tree_value) pi);
3247 }
3248 else
3249 pi = (priority_info) n->value;
3250
3251 return pi;
3252 }
3253
3254 /* The effective initialization priority of a DECL. */
3255
3256 #define DECL_EFFECTIVE_INIT_PRIORITY(decl) \
3257 ((!DECL_HAS_INIT_PRIORITY_P (decl) || DECL_INIT_PRIORITY (decl) == 0) \
3258 ? DEFAULT_INIT_PRIORITY : DECL_INIT_PRIORITY (decl))
3259
3260 /* Whether a DECL needs a guard to protect it against multiple
3261 initialization. */
3262
3263 #define NEEDS_GUARD_P(decl) (TREE_PUBLIC (decl) && (DECL_COMMON (decl) \
3264 || DECL_ONE_ONLY (decl) \
3265 || DECL_WEAK (decl)))
3266
3267 /* Called from one_static_initialization_or_destruction(),
3268 via walk_tree.
3269 Walks the initializer list of a global variable and looks for
3270 temporary variables (DECL_NAME() == NULL and DECL_ARTIFICIAL != 0)
3271 and that have their DECL_CONTEXT() == NULL.
3272 For each such temporary variable, set their DECL_CONTEXT() to
3273 the current function. This is necessary because otherwise
3274 some optimizers (enabled by -O2 -fprofile-arcs) might crash
3275 when trying to refer to a temporary variable that does not have
3276 it's DECL_CONTECT() properly set. */
3277 static tree
fix_temporary_vars_context_r(tree * node,int *,void *)3278 fix_temporary_vars_context_r (tree *node,
3279 int * /*unused*/,
3280 void * /*unused1*/)
3281 {
3282 gcc_assert (current_function_decl);
3283
3284 if (TREE_CODE (*node) == BIND_EXPR)
3285 {
3286 tree var;
3287
3288 for (var = BIND_EXPR_VARS (*node); var; var = DECL_CHAIN (var))
3289 if (TREE_CODE (var) == VAR_DECL
3290 && !DECL_NAME (var)
3291 && DECL_ARTIFICIAL (var)
3292 && !DECL_CONTEXT (var))
3293 DECL_CONTEXT (var) = current_function_decl;
3294 }
3295
3296 return NULL_TREE;
3297 }
3298
3299 /* Set up to handle the initialization or destruction of DECL. If
3300 INITP is nonzero, we are initializing the variable. Otherwise, we
3301 are destroying it. */
3302
3303 static void
one_static_initialization_or_destruction(tree decl,tree init,bool initp)3304 one_static_initialization_or_destruction (tree decl, tree init, bool initp)
3305 {
3306 tree guard_if_stmt = NULL_TREE;
3307 tree guard;
3308
3309 /* If we are supposed to destruct and there's a trivial destructor,
3310 nothing has to be done. */
3311 if (!initp
3312 && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (decl)))
3313 return;
3314
3315 /* Trick the compiler into thinking we are at the file and line
3316 where DECL was declared so that error-messages make sense, and so
3317 that the debugger will show somewhat sensible file and line
3318 information. */
3319 input_location = DECL_SOURCE_LOCATION (decl);
3320
3321 /* Make sure temporary variables in the initialiser all have
3322 their DECL_CONTEXT() set to a value different from NULL_TREE.
3323 This can happen when global variables initialisers are built.
3324 In that case, the DECL_CONTEXT() of the global variables _AND_ of all
3325 the temporary variables that might have been generated in the
3326 accompagning initialisers is NULL_TREE, meaning the variables have been
3327 declared in the global namespace.
3328 What we want to do here is to fix that and make sure the DECL_CONTEXT()
3329 of the temporaries are set to the current function decl. */
3330 cp_walk_tree_without_duplicates (&init,
3331 fix_temporary_vars_context_r,
3332 NULL);
3333
3334 /* Because of:
3335
3336 [class.access.spec]
3337
3338 Access control for implicit calls to the constructors,
3339 the conversion functions, or the destructor called to
3340 create and destroy a static data member is performed as
3341 if these calls appeared in the scope of the member's
3342 class.
3343
3344 we pretend we are in a static member function of the class of
3345 which the DECL is a member. */
3346 if (member_p (decl))
3347 {
3348 DECL_CONTEXT (current_function_decl) = DECL_CONTEXT (decl);
3349 DECL_STATIC_FUNCTION_P (current_function_decl) = 1;
3350 }
3351
3352 /* Assume we don't need a guard. */
3353 guard = NULL_TREE;
3354 /* We need a guard if this is an object with external linkage that
3355 might be initialized in more than one place. (For example, a
3356 static data member of a template, when the data member requires
3357 construction.) */
3358 if (NEEDS_GUARD_P (decl))
3359 {
3360 tree guard_cond;
3361
3362 guard = get_guard (decl);
3363
3364 /* When using __cxa_atexit, we just check the GUARD as we would
3365 for a local static. */
3366 if (flag_use_cxa_atexit)
3367 {
3368 /* When using __cxa_atexit, we never try to destroy
3369 anything from a static destructor. */
3370 gcc_assert (initp);
3371 guard_cond = get_guard_cond (guard);
3372 }
3373 /* If we don't have __cxa_atexit, then we will be running
3374 destructors from .fini sections, or their equivalents. So,
3375 we need to know how many times we've tried to initialize this
3376 object. We do initializations only if the GUARD is zero,
3377 i.e., if we are the first to initialize the variable. We do
3378 destructions only if the GUARD is one, i.e., if we are the
3379 last to destroy the variable. */
3380 else if (initp)
3381 guard_cond
3382 = cp_build_binary_op (input_location,
3383 EQ_EXPR,
3384 cp_build_unary_op (PREINCREMENT_EXPR,
3385 guard,
3386 /*noconvert=*/1,
3387 tf_warning_or_error),
3388 integer_one_node,
3389 tf_warning_or_error);
3390 else
3391 guard_cond
3392 = cp_build_binary_op (input_location,
3393 EQ_EXPR,
3394 cp_build_unary_op (PREDECREMENT_EXPR,
3395 guard,
3396 /*noconvert=*/1,
3397 tf_warning_or_error),
3398 integer_zero_node,
3399 tf_warning_or_error);
3400
3401 guard_if_stmt = begin_if_stmt ();
3402 finish_if_stmt_cond (guard_cond, guard_if_stmt);
3403 }
3404
3405
3406 /* If we're using __cxa_atexit, we have not already set the GUARD,
3407 so we must do so now. */
3408 if (guard && initp && flag_use_cxa_atexit)
3409 finish_expr_stmt (set_guard (guard));
3410
3411 /* Perform the initialization or destruction. */
3412 if (initp)
3413 {
3414 if (init)
3415 finish_expr_stmt (init);
3416
3417 /* If we're using __cxa_atexit, register a function that calls the
3418 destructor for the object. */
3419 if (flag_use_cxa_atexit)
3420 finish_expr_stmt (register_dtor_fn (decl));
3421 }
3422 else
3423 finish_expr_stmt (build_cleanup (decl));
3424
3425 /* Finish the guard if-stmt, if necessary. */
3426 if (guard)
3427 {
3428 finish_then_clause (guard_if_stmt);
3429 finish_if_stmt (guard_if_stmt);
3430 }
3431
3432 /* Now that we're done with DECL we don't need to pretend to be a
3433 member of its class any longer. */
3434 DECL_CONTEXT (current_function_decl) = NULL_TREE;
3435 DECL_STATIC_FUNCTION_P (current_function_decl) = 0;
3436 }
3437
3438 /* Generate code to do the initialization or destruction of the decls in VARS,
3439 a TREE_LIST of VAR_DECL with static storage duration.
3440 Whether initialization or destruction is performed is specified by INITP. */
3441
3442 static void
do_static_initialization_or_destruction(tree vars,bool initp)3443 do_static_initialization_or_destruction (tree vars, bool initp)
3444 {
3445 tree node, init_if_stmt, cond;
3446
3447 /* Build the outer if-stmt to check for initialization or destruction. */
3448 init_if_stmt = begin_if_stmt ();
3449 cond = initp ? integer_one_node : integer_zero_node;
3450 cond = cp_build_binary_op (input_location,
3451 EQ_EXPR,
3452 initialize_p_decl,
3453 cond,
3454 tf_warning_or_error);
3455 finish_if_stmt_cond (cond, init_if_stmt);
3456
3457 node = vars;
3458 do {
3459 tree decl = TREE_VALUE (node);
3460 tree priority_if_stmt;
3461 int priority;
3462 priority_info pi;
3463
3464 /* If we don't need a destructor, there's nothing to do. Avoid
3465 creating a possibly empty if-stmt. */
3466 if (!initp && TYPE_HAS_TRIVIAL_DESTRUCTOR (TREE_TYPE (decl)))
3467 {
3468 node = TREE_CHAIN (node);
3469 continue;
3470 }
3471
3472 /* Remember that we had an initialization or finalization at this
3473 priority. */
3474 priority = DECL_EFFECTIVE_INIT_PRIORITY (decl);
3475 pi = get_priority_info (priority);
3476 if (initp)
3477 pi->initializations_p = 1;
3478 else
3479 pi->destructions_p = 1;
3480
3481 /* Conditionalize this initialization on being in the right priority
3482 and being initializing/finalizing appropriately. */
3483 priority_if_stmt = begin_if_stmt ();
3484 cond = cp_build_binary_op (input_location,
3485 EQ_EXPR,
3486 priority_decl,
3487 build_int_cst (NULL_TREE, priority),
3488 tf_warning_or_error);
3489 finish_if_stmt_cond (cond, priority_if_stmt);
3490
3491 /* Process initializers with same priority. */
3492 for (; node
3493 && DECL_EFFECTIVE_INIT_PRIORITY (TREE_VALUE (node)) == priority;
3494 node = TREE_CHAIN (node))
3495 /* Do one initialization or destruction. */
3496 one_static_initialization_or_destruction (TREE_VALUE (node),
3497 TREE_PURPOSE (node), initp);
3498
3499 /* Finish up the priority if-stmt body. */
3500 finish_then_clause (priority_if_stmt);
3501 finish_if_stmt (priority_if_stmt);
3502
3503 } while (node);
3504
3505 /* Finish up the init/destruct if-stmt body. */
3506 finish_then_clause (init_if_stmt);
3507 finish_if_stmt (init_if_stmt);
3508 }
3509
3510 /* VARS is a list of variables with static storage duration which may
3511 need initialization and/or finalization. Remove those variables
3512 that don't really need to be initialized or finalized, and return
3513 the resulting list. The order in which the variables appear in
3514 VARS is in reverse order of the order in which they should actually
3515 be initialized. The list we return is in the unreversed order;
3516 i.e., the first variable should be initialized first. */
3517
3518 static tree
prune_vars_needing_no_initialization(tree * vars)3519 prune_vars_needing_no_initialization (tree *vars)
3520 {
3521 tree *var = vars;
3522 tree result = NULL_TREE;
3523
3524 while (*var)
3525 {
3526 tree t = *var;
3527 tree decl = TREE_VALUE (t);
3528 tree init = TREE_PURPOSE (t);
3529
3530 /* Deal gracefully with error. */
3531 if (decl == error_mark_node)
3532 {
3533 var = &TREE_CHAIN (t);
3534 continue;
3535 }
3536
3537 /* The only things that can be initialized are variables. */
3538 gcc_assert (TREE_CODE (decl) == VAR_DECL);
3539
3540 /* If this object is not defined, we don't need to do anything
3541 here. */
3542 if (DECL_EXTERNAL (decl))
3543 {
3544 var = &TREE_CHAIN (t);
3545 continue;
3546 }
3547
3548 /* Also, if the initializer already contains errors, we can bail
3549 out now. */
3550 if (init && TREE_CODE (init) == TREE_LIST
3551 && value_member (error_mark_node, init))
3552 {
3553 var = &TREE_CHAIN (t);
3554 continue;
3555 }
3556
3557 /* This variable is going to need initialization and/or
3558 finalization, so we add it to the list. */
3559 *var = TREE_CHAIN (t);
3560 TREE_CHAIN (t) = result;
3561 result = t;
3562 }
3563
3564 return result;
3565 }
3566
3567 /* Make sure we have told the back end about all the variables in
3568 VARS. */
3569
3570 static void
write_out_vars(tree vars)3571 write_out_vars (tree vars)
3572 {
3573 tree v;
3574
3575 for (v = vars; v; v = TREE_CHAIN (v))
3576 {
3577 tree var = TREE_VALUE (v);
3578 if (!var_finalized_p (var))
3579 {
3580 import_export_decl (var);
3581 rest_of_decl_compilation (var, 1, 1);
3582 }
3583 }
3584 }
3585
3586 /* Generate a static constructor (if CONSTRUCTOR_P) or destructor
3587 (otherwise) that will initialize all global objects with static
3588 storage duration having the indicated PRIORITY. */
3589
3590 static void
generate_ctor_or_dtor_function(bool constructor_p,int priority,location_t * locus)3591 generate_ctor_or_dtor_function (bool constructor_p, int priority,
3592 location_t *locus)
3593 {
3594 char function_key;
3595 tree fndecl;
3596 tree body;
3597 size_t i;
3598
3599 input_location = *locus;
3600 /* ??? */
3601 /* Was: locus->line++; */
3602
3603 /* We use `I' to indicate initialization and `D' to indicate
3604 destruction. */
3605 function_key = constructor_p ? 'I' : 'D';
3606
3607 /* We emit the function lazily, to avoid generating empty
3608 global constructors and destructors. */
3609 body = NULL_TREE;
3610
3611 /* For Objective-C++, we may need to initialize metadata found in this module.
3612 This must be done _before_ any other static initializations. */
3613 if (c_dialect_objc () && (priority == DEFAULT_INIT_PRIORITY)
3614 && constructor_p && objc_static_init_needed_p ())
3615 {
3616 body = start_objects (function_key, priority);
3617 objc_generate_static_init_call (NULL_TREE);
3618 }
3619
3620 /* Call the static storage duration function with appropriate
3621 arguments. */
3622 FOR_EACH_VEC_SAFE_ELT (ssdf_decls, i, fndecl)
3623 {
3624 /* Calls to pure or const functions will expand to nothing. */
3625 if (! (flags_from_decl_or_type (fndecl) & (ECF_CONST | ECF_PURE)))
3626 {
3627 tree call;
3628
3629 if (! body)
3630 body = start_objects (function_key, priority);
3631
3632 call = cp_build_function_call_nary (fndecl, tf_warning_or_error,
3633 build_int_cst (NULL_TREE,
3634 constructor_p),
3635 build_int_cst (NULL_TREE,
3636 priority),
3637 NULL_TREE);
3638 finish_expr_stmt (call);
3639 }
3640 }
3641
3642 /* Close out the function. */
3643 if (body)
3644 finish_objects (function_key, priority, body);
3645 }
3646
3647 /* Generate constructor and destructor functions for the priority
3648 indicated by N. */
3649
3650 static int
generate_ctor_and_dtor_functions_for_priority(splay_tree_node n,void * data)3651 generate_ctor_and_dtor_functions_for_priority (splay_tree_node n, void * data)
3652 {
3653 location_t *locus = (location_t *) data;
3654 int priority = (int) n->key;
3655 priority_info pi = (priority_info) n->value;
3656
3657 /* Generate the functions themselves, but only if they are really
3658 needed. */
3659 if (pi->initializations_p)
3660 generate_ctor_or_dtor_function (/*constructor_p=*/true, priority, locus);
3661 if (pi->destructions_p)
3662 generate_ctor_or_dtor_function (/*constructor_p=*/false, priority, locus);
3663
3664 /* Keep iterating. */
3665 return 0;
3666 }
3667
3668 /* Java requires that we be able to reference a local address for a
3669 method, and not be confused by PLT entries. If hidden aliases are
3670 supported, collect and return all the functions for which we should
3671 emit a hidden alias. */
3672
3673 static struct pointer_set_t *
collect_candidates_for_java_method_aliases(void)3674 collect_candidates_for_java_method_aliases (void)
3675 {
3676 struct cgraph_node *node;
3677 struct pointer_set_t *candidates = NULL;
3678
3679 #ifndef HAVE_GAS_HIDDEN
3680 return candidates;
3681 #endif
3682
3683 FOR_EACH_FUNCTION (node)
3684 {
3685 tree fndecl = node->symbol.decl;
3686
3687 if (DECL_CONTEXT (fndecl)
3688 && TYPE_P (DECL_CONTEXT (fndecl))
3689 && TYPE_FOR_JAVA (DECL_CONTEXT (fndecl))
3690 && TARGET_USE_LOCAL_THUNK_ALIAS_P (fndecl))
3691 {
3692 if (candidates == NULL)
3693 candidates = pointer_set_create ();
3694 pointer_set_insert (candidates, fndecl);
3695 }
3696 }
3697
3698 return candidates;
3699 }
3700
3701
3702 /* Java requires that we be able to reference a local address for a
3703 method, and not be confused by PLT entries. If hidden aliases are
3704 supported, emit one for each java function that we've emitted.
3705 CANDIDATES is the set of FUNCTION_DECLs that were gathered
3706 by collect_candidates_for_java_method_aliases. */
3707
3708 static void
build_java_method_aliases(struct pointer_set_t * candidates)3709 build_java_method_aliases (struct pointer_set_t *candidates)
3710 {
3711 struct cgraph_node *node;
3712
3713 #ifndef HAVE_GAS_HIDDEN
3714 return;
3715 #endif
3716
3717 FOR_EACH_FUNCTION (node)
3718 {
3719 tree fndecl = node->symbol.decl;
3720
3721 if (TREE_ASM_WRITTEN (fndecl)
3722 && pointer_set_contains (candidates, fndecl))
3723 {
3724 /* Mangle the name in a predictable way; we need to reference
3725 this from a java compiled object file. */
3726 tree oid, nid, alias;
3727 const char *oname;
3728 char *nname;
3729
3730 oid = DECL_ASSEMBLER_NAME (fndecl);
3731 oname = IDENTIFIER_POINTER (oid);
3732 gcc_assert (oname[0] == '_' && oname[1] == 'Z');
3733 nname = ACONCAT (("_ZGA", oname+2, NULL));
3734 nid = get_identifier (nname);
3735
3736 alias = make_alias_for (fndecl, nid);
3737 TREE_PUBLIC (alias) = 1;
3738 DECL_VISIBILITY (alias) = VISIBILITY_HIDDEN;
3739
3740 assemble_alias (alias, oid);
3741 }
3742 }
3743 }
3744
3745 /* Return C++ property of T, based on given operation OP. */
3746
3747 static int
cpp_check(tree t,cpp_operation op)3748 cpp_check (tree t, cpp_operation op)
3749 {
3750 switch (op)
3751 {
3752 case IS_ABSTRACT:
3753 return DECL_PURE_VIRTUAL_P (t);
3754 case IS_CONSTRUCTOR:
3755 return DECL_CONSTRUCTOR_P (t);
3756 case IS_DESTRUCTOR:
3757 return DECL_DESTRUCTOR_P (t);
3758 case IS_COPY_CONSTRUCTOR:
3759 return DECL_COPY_CONSTRUCTOR_P (t);
3760 case IS_TEMPLATE:
3761 return TREE_CODE (t) == TEMPLATE_DECL;
3762 default:
3763 return 0;
3764 }
3765 }
3766
3767 /* Collect source file references recursively, starting from NAMESPC. */
3768
3769 static void
collect_source_refs(tree namespc)3770 collect_source_refs (tree namespc)
3771 {
3772 tree t;
3773
3774 if (!namespc)
3775 return;
3776
3777 /* Iterate over names in this name space. */
3778 for (t = NAMESPACE_LEVEL (namespc)->names; t; t = TREE_CHAIN (t))
3779 if (!DECL_IS_BUILTIN (t) )
3780 collect_source_ref (DECL_SOURCE_FILE (t));
3781
3782 /* Dump siblings, if any */
3783 collect_source_refs (TREE_CHAIN (namespc));
3784
3785 /* Dump children, if any */
3786 collect_source_refs (NAMESPACE_LEVEL (namespc)->namespaces);
3787 }
3788
3789 /* Collect decls relevant to SOURCE_FILE from all namespaces recursively,
3790 starting from NAMESPC. */
3791
3792 static void
collect_ada_namespace(tree namespc,const char * source_file)3793 collect_ada_namespace (tree namespc, const char *source_file)
3794 {
3795 if (!namespc)
3796 return;
3797
3798 /* Collect decls from this namespace */
3799 collect_ada_nodes (NAMESPACE_LEVEL (namespc)->names, source_file);
3800
3801 /* Collect siblings, if any */
3802 collect_ada_namespace (TREE_CHAIN (namespc), source_file);
3803
3804 /* Collect children, if any */
3805 collect_ada_namespace (NAMESPACE_LEVEL (namespc)->namespaces, source_file);
3806 }
3807
3808 /* Returns true iff there is a definition available for variable or
3809 function DECL. */
3810
3811 static bool
decl_defined_p(tree decl)3812 decl_defined_p (tree decl)
3813 {
3814 if (TREE_CODE (decl) == FUNCTION_DECL)
3815 return (DECL_INITIAL (decl) != NULL_TREE);
3816 else
3817 {
3818 gcc_assert (TREE_CODE (decl) == VAR_DECL);
3819 return !DECL_EXTERNAL (decl);
3820 }
3821 }
3822
3823 /* Nonzero for a VAR_DECL whose value can be used in a constant expression.
3824
3825 [expr.const]
3826
3827 An integral constant-expression can only involve ... const
3828 variables of integral or enumeration types initialized with
3829 constant expressions ...
3830
3831 C++0x also allows constexpr variables and temporaries initialized
3832 with constant expressions. We handle the former here, but the latter
3833 are just folded away in cxx_eval_constant_expression.
3834
3835 The standard does not require that the expression be non-volatile.
3836 G++ implements the proposed correction in DR 457. */
3837
3838 bool
decl_constant_var_p(tree decl)3839 decl_constant_var_p (tree decl)
3840 {
3841 if (!decl_maybe_constant_var_p (decl))
3842 return false;
3843
3844 /* We don't know if a template static data member is initialized with
3845 a constant expression until we instantiate its initializer. Even
3846 in the case of a constexpr variable, we can't treat it as a
3847 constant until its initializer is complete in case it's used in
3848 its own initializer. */
3849 mark_used (decl);
3850 return DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl);
3851 }
3852
3853 /* Returns true if DECL could be a symbolic constant variable, depending on
3854 its initializer. */
3855
3856 bool
decl_maybe_constant_var_p(tree decl)3857 decl_maybe_constant_var_p (tree decl)
3858 {
3859 tree type = TREE_TYPE (decl);
3860 if (TREE_CODE (decl) != VAR_DECL)
3861 return false;
3862 if (DECL_DECLARED_CONSTEXPR_P (decl))
3863 return true;
3864 return (CP_TYPE_CONST_NON_VOLATILE_P (type)
3865 && INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3866 }
3867
3868 /* Complain that DECL uses a type with no linkage but is never defined. */
3869
3870 static void
no_linkage_error(tree decl)3871 no_linkage_error (tree decl)
3872 {
3873 tree t = no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/false);
3874 if (TYPE_ANONYMOUS_P (t))
3875 {
3876 permerror (0, "%q+#D, declared using anonymous type, "
3877 "is used but never defined", decl);
3878 if (is_typedef_decl (TYPE_NAME (t)))
3879 permerror (0, "%q+#D does not refer to the unqualified type, "
3880 "so it is not used for linkage", TYPE_NAME (t));
3881 }
3882 else
3883 permerror (0, "%q+#D, declared using local type %qT, "
3884 "is used but never defined", decl, t);
3885 }
3886
3887 /* Collect declarations from all namespaces relevant to SOURCE_FILE. */
3888
3889 static void
collect_all_refs(const char * source_file)3890 collect_all_refs (const char *source_file)
3891 {
3892 collect_ada_namespace (global_namespace, source_file);
3893 }
3894
3895 /* Clear DECL_EXTERNAL for NODE. */
3896
3897 static bool
clear_decl_external(struct cgraph_node * node,void *)3898 clear_decl_external (struct cgraph_node *node, void * /*data*/)
3899 {
3900 DECL_EXTERNAL (node->symbol.decl) = 0;
3901 return false;
3902 }
3903
3904 /* Build up the function to run dynamic initializers for thread_local
3905 variables in this translation unit and alias the init functions for the
3906 individual variables to it. */
3907
3908 static void
handle_tls_init(void)3909 handle_tls_init (void)
3910 {
3911 tree vars = prune_vars_needing_no_initialization (&tls_aggregates);
3912 if (vars == NULL_TREE)
3913 return;
3914
3915 location_t loc = DECL_SOURCE_LOCATION (TREE_VALUE (vars));
3916
3917 write_out_vars (vars);
3918
3919 tree guard = build_decl (loc, VAR_DECL, get_identifier ("__tls_guard"),
3920 boolean_type_node);
3921 TREE_PUBLIC (guard) = false;
3922 TREE_STATIC (guard) = true;
3923 DECL_ARTIFICIAL (guard) = true;
3924 DECL_IGNORED_P (guard) = true;
3925 TREE_USED (guard) = true;
3926 DECL_TLS_MODEL (guard) = decl_default_tls_model (guard);
3927 pushdecl_top_level_and_finish (guard, NULL_TREE);
3928
3929 tree fn = get_local_tls_init_fn ();
3930 start_preparsed_function (fn, NULL_TREE, SF_PRE_PARSED);
3931 tree body = begin_function_body ();
3932 tree if_stmt = begin_if_stmt ();
3933 tree cond = cp_build_unary_op (TRUTH_NOT_EXPR, guard, false,
3934 tf_warning_or_error);
3935 finish_if_stmt_cond (cond, if_stmt);
3936 finish_expr_stmt (cp_build_modify_expr (guard, NOP_EXPR, boolean_true_node,
3937 tf_warning_or_error));
3938 for (; vars; vars = TREE_CHAIN (vars))
3939 {
3940 tree var = TREE_VALUE (vars);
3941 tree init = TREE_PURPOSE (vars);
3942 one_static_initialization_or_destruction (var, init, true);
3943
3944 #ifdef ASM_OUTPUT_DEF
3945 /* Output init aliases even with -fno-extern-tls-init. */
3946 if (TREE_PUBLIC (var))
3947 {
3948 tree single_init_fn = get_tls_init_fn (var);
3949 cgraph_node *alias
3950 = cgraph_same_body_alias (cgraph_get_create_node (fn),
3951 single_init_fn, fn);
3952 gcc_assert (alias != NULL);
3953 }
3954 #endif
3955 }
3956
3957 finish_then_clause (if_stmt);
3958 finish_if_stmt (if_stmt);
3959 finish_function_body (body);
3960 expand_or_defer_fn (finish_function (0));
3961 }
3962
3963 /* This routine is called at the end of compilation.
3964 Its job is to create all the code needed to initialize and
3965 destroy the global aggregates. We do the destruction
3966 first, since that way we only need to reverse the decls once. */
3967
3968 void
cp_write_global_declarations(void)3969 cp_write_global_declarations (void)
3970 {
3971 tree vars;
3972 bool reconsider;
3973 size_t i;
3974 location_t locus;
3975 unsigned ssdf_count = 0;
3976 int retries = 0;
3977 tree decl;
3978 struct pointer_set_t *candidates;
3979
3980 locus = input_location;
3981 at_eof = 1;
3982
3983 /* Bad parse errors. Just forget about it. */
3984 if (! global_bindings_p () || current_class_type
3985 || !vec_safe_is_empty (decl_namespace_list))
3986 return;
3987
3988 /* This is the point to write out a PCH if we're doing that.
3989 In that case we do not want to do anything else. */
3990 if (pch_file)
3991 {
3992 c_common_write_pch ();
3993 return;
3994 }
3995
3996 cgraph_process_same_body_aliases ();
3997
3998 /* Handle -fdump-ada-spec[-slim] */
3999 if (flag_dump_ada_spec || flag_dump_ada_spec_slim)
4000 {
4001 if (flag_dump_ada_spec_slim)
4002 collect_source_ref (main_input_filename);
4003 else
4004 collect_source_refs (global_namespace);
4005
4006 dump_ada_specs (collect_all_refs, cpp_check);
4007 }
4008
4009 /* FIXME - huh? was input_line -= 1;*/
4010
4011 timevar_start (TV_PHASE_DEFERRED);
4012
4013 /* We now have to write out all the stuff we put off writing out.
4014 These include:
4015
4016 o Template specializations that we have not yet instantiated,
4017 but which are needed.
4018 o Initialization and destruction for non-local objects with
4019 static storage duration. (Local objects with static storage
4020 duration are initialized when their scope is first entered,
4021 and are cleaned up via atexit.)
4022 o Virtual function tables.
4023
4024 All of these may cause others to be needed. For example,
4025 instantiating one function may cause another to be needed, and
4026 generating the initializer for an object may cause templates to be
4027 instantiated, etc., etc. */
4028
4029 emit_support_tinfos ();
4030
4031 do
4032 {
4033 tree t;
4034 tree decl;
4035
4036 reconsider = false;
4037
4038 /* If there are templates that we've put off instantiating, do
4039 them now. */
4040 instantiate_pending_templates (retries);
4041 ggc_collect ();
4042
4043 /* Write out virtual tables as required. Note that writing out
4044 the virtual table for a template class may cause the
4045 instantiation of members of that class. If we write out
4046 vtables then we remove the class from our list so we don't
4047 have to look at it again. */
4048
4049 while (keyed_classes != NULL_TREE
4050 && maybe_emit_vtables (TREE_VALUE (keyed_classes)))
4051 {
4052 reconsider = true;
4053 keyed_classes = TREE_CHAIN (keyed_classes);
4054 }
4055
4056 t = keyed_classes;
4057 if (t != NULL_TREE)
4058 {
4059 tree next = TREE_CHAIN (t);
4060
4061 while (next)
4062 {
4063 if (maybe_emit_vtables (TREE_VALUE (next)))
4064 {
4065 reconsider = true;
4066 TREE_CHAIN (t) = TREE_CHAIN (next);
4067 }
4068 else
4069 t = next;
4070
4071 next = TREE_CHAIN (t);
4072 }
4073 }
4074
4075 /* Write out needed type info variables. We have to be careful
4076 looping through unemitted decls, because emit_tinfo_decl may
4077 cause other variables to be needed. New elements will be
4078 appended, and we remove from the vector those that actually
4079 get emitted. */
4080 for (i = unemitted_tinfo_decls->length ();
4081 unemitted_tinfo_decls->iterate (--i, &t);)
4082 if (emit_tinfo_decl (t))
4083 {
4084 reconsider = true;
4085 unemitted_tinfo_decls->unordered_remove (i);
4086 }
4087
4088 /* The list of objects with static storage duration is built up
4089 in reverse order. We clear STATIC_AGGREGATES so that any new
4090 aggregates added during the initialization of these will be
4091 initialized in the correct order when we next come around the
4092 loop. */
4093 vars = prune_vars_needing_no_initialization (&static_aggregates);
4094
4095 if (vars)
4096 {
4097 /* We need to start a new initialization function each time
4098 through the loop. That's because we need to know which
4099 vtables have been referenced, and TREE_SYMBOL_REFERENCED
4100 isn't computed until a function is finished, and written
4101 out. That's a deficiency in the back end. When this is
4102 fixed, these initialization functions could all become
4103 inline, with resulting performance improvements. */
4104 tree ssdf_body;
4105
4106 /* Set the line and file, so that it is obviously not from
4107 the source file. */
4108 input_location = locus;
4109 ssdf_body = start_static_storage_duration_function (ssdf_count);
4110
4111 /* Make sure the back end knows about all the variables. */
4112 write_out_vars (vars);
4113
4114 /* First generate code to do all the initializations. */
4115 if (vars)
4116 do_static_initialization_or_destruction (vars, /*initp=*/true);
4117
4118 /* Then, generate code to do all the destructions. Do these
4119 in reverse order so that the most recently constructed
4120 variable is the first destroyed. If we're using
4121 __cxa_atexit, then we don't need to do this; functions
4122 were registered at initialization time to destroy the
4123 local statics. */
4124 if (!flag_use_cxa_atexit && vars)
4125 {
4126 vars = nreverse (vars);
4127 do_static_initialization_or_destruction (vars, /*initp=*/false);
4128 }
4129 else
4130 vars = NULL_TREE;
4131
4132 /* Finish up the static storage duration function for this
4133 round. */
4134 input_location = locus;
4135 finish_static_storage_duration_function (ssdf_body);
4136
4137 /* All those initializations and finalizations might cause
4138 us to need more inline functions, more template
4139 instantiations, etc. */
4140 reconsider = true;
4141 ssdf_count++;
4142 /* ??? was: locus.line++; */
4143 }
4144
4145 /* Now do the same for thread_local variables. */
4146 handle_tls_init ();
4147
4148 /* Go through the set of inline functions whose bodies have not
4149 been emitted yet. If out-of-line copies of these functions
4150 are required, emit them. */
4151 FOR_EACH_VEC_SAFE_ELT (deferred_fns, i, decl)
4152 {
4153 /* Does it need synthesizing? */
4154 if (DECL_DEFAULTED_FN (decl) && ! DECL_INITIAL (decl)
4155 && (! DECL_REALLY_EXTERN (decl) || possibly_inlined_p (decl)))
4156 {
4157 /* Even though we're already at the top-level, we push
4158 there again. That way, when we pop back a few lines
4159 hence, all of our state is restored. Otherwise,
4160 finish_function doesn't clean things up, and we end
4161 up with CURRENT_FUNCTION_DECL set. */
4162 push_to_top_level ();
4163 /* The decl's location will mark where it was first
4164 needed. Save that so synthesize method can indicate
4165 where it was needed from, in case of error */
4166 input_location = DECL_SOURCE_LOCATION (decl);
4167 synthesize_method (decl);
4168 pop_from_top_level ();
4169 reconsider = true;
4170 }
4171
4172 if (!DECL_INITIAL (decl) && decl_tls_wrapper_p (decl))
4173 generate_tls_wrapper (decl);
4174
4175 if (!DECL_SAVED_TREE (decl))
4176 continue;
4177
4178 /* We lie to the back end, pretending that some functions
4179 are not defined when they really are. This keeps these
4180 functions from being put out unnecessarily. But, we must
4181 stop lying when the functions are referenced, or if they
4182 are not comdat since they need to be put out now. If
4183 DECL_INTERFACE_KNOWN, then we have already set
4184 DECL_EXTERNAL appropriately, so there's no need to check
4185 again, and we do not want to clear DECL_EXTERNAL if a
4186 previous call to import_export_decl set it.
4187
4188 This is done in a separate for cycle, because if some
4189 deferred function is contained in another deferred
4190 function later in deferred_fns varray,
4191 rest_of_compilation would skip this function and we
4192 really cannot expand the same function twice. */
4193 import_export_decl (decl);
4194 if (DECL_NOT_REALLY_EXTERN (decl)
4195 && DECL_INITIAL (decl)
4196 && decl_needed_p (decl))
4197 {
4198 struct cgraph_node *node, *next;
4199
4200 node = cgraph_get_node (decl);
4201 if (node->same_body_alias)
4202 node = cgraph_alias_aliased_node (node);
4203
4204 cgraph_for_node_and_aliases (node, clear_decl_external,
4205 NULL, true);
4206 /* If we mark !DECL_EXTERNAL one of the symbols in some comdat
4207 group, we need to mark all symbols in the same comdat group
4208 that way. */
4209 if (node->symbol.same_comdat_group)
4210 for (next = cgraph (node->symbol.same_comdat_group);
4211 next != node;
4212 next = cgraph (next->symbol.same_comdat_group))
4213 cgraph_for_node_and_aliases (next, clear_decl_external,
4214 NULL, true);
4215 }
4216
4217 /* If we're going to need to write this function out, and
4218 there's already a body for it, create RTL for it now.
4219 (There might be no body if this is a method we haven't
4220 gotten around to synthesizing yet.) */
4221 if (!DECL_EXTERNAL (decl)
4222 && decl_needed_p (decl)
4223 && !TREE_ASM_WRITTEN (decl)
4224 && !cgraph_get_node (decl)->local.finalized)
4225 {
4226 /* We will output the function; no longer consider it in this
4227 loop. */
4228 DECL_DEFER_OUTPUT (decl) = 0;
4229 /* Generate RTL for this function now that we know we
4230 need it. */
4231 expand_or_defer_fn (decl);
4232 /* If we're compiling -fsyntax-only pretend that this
4233 function has been written out so that we don't try to
4234 expand it again. */
4235 if (flag_syntax_only)
4236 TREE_ASM_WRITTEN (decl) = 1;
4237 reconsider = true;
4238 }
4239 }
4240
4241 if (walk_namespaces (wrapup_globals_for_namespace, /*data=*/0))
4242 reconsider = true;
4243
4244 /* Static data members are just like namespace-scope globals. */
4245 FOR_EACH_VEC_SAFE_ELT (pending_statics, i, decl)
4246 {
4247 if (var_finalized_p (decl) || DECL_REALLY_EXTERN (decl)
4248 /* Don't write it out if we haven't seen a definition. */
4249 || DECL_IN_AGGR_P (decl))
4250 continue;
4251 import_export_decl (decl);
4252 /* If this static data member is needed, provide it to the
4253 back end. */
4254 if (DECL_NOT_REALLY_EXTERN (decl) && decl_needed_p (decl))
4255 DECL_EXTERNAL (decl) = 0;
4256 }
4257 if (vec_safe_length (pending_statics) != 0
4258 && wrapup_global_declarations (pending_statics->address (),
4259 pending_statics->length ()))
4260 reconsider = true;
4261
4262 retries++;
4263 }
4264 while (reconsider);
4265
4266 /* All used inline functions must have a definition at this point. */
4267 FOR_EACH_VEC_SAFE_ELT (deferred_fns, i, decl)
4268 {
4269 if (/* Check online inline functions that were actually used. */
4270 DECL_ODR_USED (decl) && DECL_DECLARED_INLINE_P (decl)
4271 /* If the definition actually was available here, then the
4272 fact that the function was not defined merely represents
4273 that for some reason (use of a template repository,
4274 #pragma interface, etc.) we decided not to emit the
4275 definition here. */
4276 && !DECL_INITIAL (decl)
4277 /* Don't complain if the template was defined. */
4278 && !(DECL_TEMPLATE_INSTANTIATION (decl)
4279 && DECL_INITIAL (DECL_TEMPLATE_RESULT
4280 (template_for_substitution (decl)))))
4281 {
4282 warning (0, "inline function %q+D used but never defined", decl);
4283 /* Avoid a duplicate warning from check_global_declaration_1. */
4284 TREE_NO_WARNING (decl) = 1;
4285 }
4286 }
4287
4288 /* So must decls that use a type with no linkage. */
4289 FOR_EACH_VEC_SAFE_ELT (no_linkage_decls, i, decl)
4290 if (!decl_defined_p (decl))
4291 no_linkage_error (decl);
4292
4293 /* Then, do the Objective-C stuff. This is where all the
4294 Objective-C module stuff gets generated (symtab,
4295 class/protocol/selector lists etc). This must be done after C++
4296 templates, destructors etc. so that selectors used in C++
4297 templates are properly allocated. */
4298 if (c_dialect_objc ())
4299 objc_write_global_declarations ();
4300
4301 /* We give C linkage to static constructors and destructors. */
4302 push_lang_context (lang_name_c);
4303
4304 /* Generate initialization and destruction functions for all
4305 priorities for which they are required. */
4306 if (priority_info_map)
4307 splay_tree_foreach (priority_info_map,
4308 generate_ctor_and_dtor_functions_for_priority,
4309 /*data=*/&locus);
4310 else if (c_dialect_objc () && objc_static_init_needed_p ())
4311 /* If this is obj-c++ and we need a static init, call
4312 generate_ctor_or_dtor_function. */
4313 generate_ctor_or_dtor_function (/*constructor_p=*/true,
4314 DEFAULT_INIT_PRIORITY, &locus);
4315
4316 /* We're done with the splay-tree now. */
4317 if (priority_info_map)
4318 splay_tree_delete (priority_info_map);
4319
4320 /* Generate any missing aliases. */
4321 maybe_apply_pending_pragma_weaks ();
4322
4323 /* We're done with static constructors, so we can go back to "C++"
4324 linkage now. */
4325 pop_lang_context ();
4326
4327 /* Collect candidates for Java hidden aliases. */
4328 candidates = collect_candidates_for_java_method_aliases ();
4329
4330 timevar_stop (TV_PHASE_DEFERRED);
4331 timevar_start (TV_PHASE_OPT_GEN);
4332
4333 finalize_compilation_unit ();
4334
4335 timevar_stop (TV_PHASE_OPT_GEN);
4336 timevar_start (TV_PHASE_CHECK_DBGINFO);
4337
4338 /* Now, issue warnings about static, but not defined, functions,
4339 etc., and emit debugging information. */
4340 walk_namespaces (wrapup_globals_for_namespace, /*data=*/&reconsider);
4341 if (vec_safe_length (pending_statics) != 0)
4342 {
4343 check_global_declarations (pending_statics->address (),
4344 pending_statics->length ());
4345 emit_debug_global_declarations (pending_statics->address (),
4346 pending_statics->length ());
4347 }
4348
4349 perform_deferred_noexcept_checks ();
4350
4351 /* Generate hidden aliases for Java. */
4352 if (candidates)
4353 {
4354 build_java_method_aliases (candidates);
4355 pointer_set_destroy (candidates);
4356 }
4357
4358 finish_repo ();
4359
4360 /* The entire file is now complete. If requested, dump everything
4361 to a file. */
4362 {
4363 int flags;
4364 FILE *stream = dump_begin (TDI_tu, &flags);
4365
4366 if (stream)
4367 {
4368 dump_node (global_namespace, flags & ~TDF_SLIM, stream);
4369 dump_end (TDI_tu, stream);
4370 }
4371 }
4372
4373 if (flag_detailed_statistics)
4374 {
4375 dump_tree_statistics ();
4376 dump_time_statistics ();
4377 }
4378 input_location = locus;
4379
4380 #ifdef ENABLE_CHECKING
4381 validate_conversion_obstack ();
4382 #endif /* ENABLE_CHECKING */
4383
4384 timevar_stop (TV_PHASE_CHECK_DBGINFO);
4385 }
4386
4387 /* FN is an OFFSET_REF, DOTSTAR_EXPR or MEMBER_REF indicating the
4388 function to call in parse-tree form; it has not yet been
4389 semantically analyzed. ARGS are the arguments to the function.
4390 They have already been semantically analyzed. This may change
4391 ARGS. */
4392
4393 tree
build_offset_ref_call_from_tree(tree fn,vec<tree,va_gc> ** args,tsubst_flags_t complain)4394 build_offset_ref_call_from_tree (tree fn, vec<tree, va_gc> **args,
4395 tsubst_flags_t complain)
4396 {
4397 tree orig_fn;
4398 vec<tree, va_gc> *orig_args = NULL;
4399 tree expr;
4400 tree object;
4401
4402 orig_fn = fn;
4403 object = TREE_OPERAND (fn, 0);
4404
4405 if (processing_template_decl)
4406 {
4407 gcc_assert (TREE_CODE (fn) == DOTSTAR_EXPR
4408 || TREE_CODE (fn) == MEMBER_REF);
4409 if (type_dependent_expression_p (fn)
4410 || any_type_dependent_arguments_p (*args))
4411 return build_nt_call_vec (fn, *args);
4412
4413 orig_args = make_tree_vector_copy (*args);
4414
4415 /* Transform the arguments and add the implicit "this"
4416 parameter. That must be done before the FN is transformed
4417 because we depend on the form of FN. */
4418 make_args_non_dependent (*args);
4419 object = build_non_dependent_expr (object);
4420 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4421 {
4422 if (TREE_CODE (fn) == DOTSTAR_EXPR)
4423 object = cp_build_addr_expr (object, complain);
4424 vec_safe_insert (*args, 0, object);
4425 }
4426 /* Now that the arguments are done, transform FN. */
4427 fn = build_non_dependent_expr (fn);
4428 }
4429
4430 /* A qualified name corresponding to a bound pointer-to-member is
4431 represented as an OFFSET_REF:
4432
4433 struct B { void g(); };
4434 void (B::*p)();
4435 void B::g() { (this->*p)(); } */
4436 if (TREE_CODE (fn) == OFFSET_REF)
4437 {
4438 tree object_addr = cp_build_addr_expr (object, complain);
4439 fn = TREE_OPERAND (fn, 1);
4440 fn = get_member_function_from_ptrfunc (&object_addr, fn,
4441 complain);
4442 vec_safe_insert (*args, 0, object_addr);
4443 }
4444
4445 if (CLASS_TYPE_P (TREE_TYPE (fn)))
4446 expr = build_op_call (fn, args, complain);
4447 else
4448 expr = cp_build_function_call_vec (fn, args, complain);
4449 if (processing_template_decl && expr != error_mark_node)
4450 expr = build_min_non_dep_call_vec (expr, orig_fn, orig_args);
4451
4452 if (orig_args != NULL)
4453 release_tree_vector (orig_args);
4454
4455 return expr;
4456 }
4457
4458
4459 void
check_default_args(tree x)4460 check_default_args (tree x)
4461 {
4462 tree arg = TYPE_ARG_TYPES (TREE_TYPE (x));
4463 bool saw_def = false;
4464 int i = 0 - (TREE_CODE (TREE_TYPE (x)) == METHOD_TYPE);
4465 for (; arg && arg != void_list_node; arg = TREE_CHAIN (arg), ++i)
4466 {
4467 if (TREE_PURPOSE (arg))
4468 saw_def = true;
4469 else if (saw_def)
4470 {
4471 error ("default argument missing for parameter %P of %q+#D", i, x);
4472 TREE_PURPOSE (arg) = error_mark_node;
4473 }
4474 }
4475 }
4476
4477 /* Return true if function DECL can be inlined. This is used to force
4478 instantiation of methods that might be interesting for inlining. */
4479 bool
possibly_inlined_p(tree decl)4480 possibly_inlined_p (tree decl)
4481 {
4482 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL);
4483 if (DECL_UNINLINABLE (decl))
4484 return false;
4485 if (!optimize || pragma_java_exceptions)
4486 return DECL_DECLARED_INLINE_P (decl);
4487 /* When optimizing, we might inline everything when flatten
4488 attribute or heuristics inlining for size or autoinlining
4489 is used. */
4490 return true;
4491 }
4492
4493 /* Mark DECL (either a _DECL or a BASELINK) as "used" in the program.
4494 If DECL is a specialization or implicitly declared class member,
4495 generate the actual definition. Return false if something goes
4496 wrong, true otherwise. */
4497
4498 bool
mark_used(tree decl)4499 mark_used (tree decl)
4500 {
4501 /* If DECL is a BASELINK for a single function, then treat it just
4502 like the DECL for the function. Otherwise, if the BASELINK is
4503 for an overloaded function, we don't know which function was
4504 actually used until after overload resolution. */
4505 if (BASELINK_P (decl))
4506 {
4507 decl = BASELINK_FUNCTIONS (decl);
4508 if (really_overloaded_fn (decl))
4509 return true;
4510 decl = OVL_CURRENT (decl);
4511 }
4512
4513 /* Set TREE_USED for the benefit of -Wunused. */
4514 TREE_USED (decl) = 1;
4515 if (DECL_CLONED_FUNCTION_P (decl))
4516 TREE_USED (DECL_CLONED_FUNCTION (decl)) = 1;
4517
4518 /* Mark enumeration types as used. */
4519 if (TREE_CODE (decl) == CONST_DECL)
4520 used_types_insert (DECL_CONTEXT (decl));
4521
4522 if (TREE_CODE (decl) == FUNCTION_DECL
4523 && DECL_DELETED_FN (decl))
4524 {
4525 if (DECL_ARTIFICIAL (decl))
4526 {
4527 if (DECL_OVERLOADED_OPERATOR_P (decl) == TYPE_EXPR
4528 && LAMBDA_TYPE_P (DECL_CONTEXT (decl)))
4529 {
4530 /* We mark a lambda conversion op as deleted if we can't
4531 generate it properly; see maybe_add_lambda_conv_op. */
4532 sorry ("converting lambda which uses %<...%> to "
4533 "function pointer");
4534 return false;
4535 }
4536 }
4537 error ("use of deleted function %qD", decl);
4538 if (!maybe_explain_implicit_delete (decl))
4539 error_at (DECL_SOURCE_LOCATION (decl), "declared here");
4540 return false;
4541 }
4542
4543 /* We can only check DECL_ODR_USED on variables or functions with
4544 DECL_LANG_SPECIFIC set, and these are also the only decls that we
4545 might need special handling for. */
4546 if ((TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)
4547 || DECL_LANG_SPECIFIC (decl) == NULL
4548 || DECL_THUNK_P (decl))
4549 {
4550 if (!processing_template_decl && type_uses_auto (TREE_TYPE (decl)))
4551 {
4552 error ("use of %qD before deduction of %<auto%>", decl);
4553 return false;
4554 }
4555 return true;
4556 }
4557
4558 /* We only want to do this processing once. We don't need to keep trying
4559 to instantiate inline templates, because unit-at-a-time will make sure
4560 we get them compiled before functions that want to inline them. */
4561 if (DECL_ODR_USED (decl))
4562 return true;
4563
4564 /* If within finish_function, defer the rest until that function
4565 finishes, otherwise it might recurse. */
4566 if (defer_mark_used_calls)
4567 {
4568 vec_safe_push (deferred_mark_used_calls, decl);
4569 return true;
4570 }
4571
4572 if (TREE_CODE (decl) == FUNCTION_DECL)
4573 maybe_instantiate_noexcept (decl);
4574
4575 /* Normally, we can wait until instantiation-time to synthesize DECL.
4576 However, if DECL is a static data member initialized with a constant
4577 or a constexpr function, we need it right now because a reference to
4578 such a data member or a call to such function is not value-dependent.
4579 For a function that uses auto in the return type, we need to instantiate
4580 it to find out its type. */
4581 if ((decl_maybe_constant_var_p (decl)
4582 || (TREE_CODE (decl) == FUNCTION_DECL
4583 && DECL_DECLARED_CONSTEXPR_P (decl))
4584 || type_uses_auto (TREE_TYPE (decl)))
4585 && DECL_LANG_SPECIFIC (decl)
4586 && DECL_TEMPLATE_INFO (decl)
4587 && !uses_template_parms (DECL_TI_ARGS (decl)))
4588 {
4589 /* Instantiating a function will result in garbage collection. We
4590 must treat this situation as if we were within the body of a
4591 function so as to avoid collecting live data only referenced from
4592 the stack (such as overload resolution candidates). */
4593 ++function_depth;
4594 instantiate_decl (decl, /*defer_ok=*/false,
4595 /*expl_inst_class_mem_p=*/false);
4596 --function_depth;
4597 }
4598
4599 if (processing_template_decl)
4600 return true;
4601
4602 /* Check this too in case we're within fold_non_dependent_expr. */
4603 if (DECL_TEMPLATE_INFO (decl)
4604 && uses_template_parms (DECL_TI_ARGS (decl)))
4605 return true;
4606
4607 if (type_uses_auto (TREE_TYPE (decl)))
4608 {
4609 error ("use of %qD before deduction of %<auto%>", decl);
4610 return false;
4611 }
4612
4613 /* If we don't need a value, then we don't need to synthesize DECL. */
4614 if (cp_unevaluated_operand != 0)
4615 return true;
4616
4617 DECL_ODR_USED (decl) = 1;
4618 if (DECL_CLONED_FUNCTION_P (decl))
4619 DECL_ODR_USED (DECL_CLONED_FUNCTION (decl)) = 1;
4620
4621 /* DR 757: A type without linkage shall not be used as the type of a
4622 variable or function with linkage, unless
4623 o the variable or function has extern "C" linkage (7.5 [dcl.link]), or
4624 o the variable or function is not used (3.2 [basic.def.odr]) or is
4625 defined in the same translation unit. */
4626 if (cxx_dialect > cxx98
4627 && decl_linkage (decl) != lk_none
4628 && !DECL_EXTERN_C_P (decl)
4629 && !DECL_ARTIFICIAL (decl)
4630 && !decl_defined_p (decl)
4631 && no_linkage_check (TREE_TYPE (decl), /*relaxed_p=*/false))
4632 {
4633 if (is_local_extern (decl))
4634 /* There's no way to define a local extern, and adding it to
4635 the vector interferes with GC, so give an error now. */
4636 no_linkage_error (decl);
4637 else
4638 vec_safe_push (no_linkage_decls, decl);
4639 }
4640
4641 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_DECLARED_INLINE_P (decl)
4642 && !DECL_INITIAL (decl) && !DECL_ARTIFICIAL (decl))
4643 /* Remember it, so we can check it was defined. */
4644 note_vague_linkage_fn (decl);
4645
4646 /* Is it a synthesized method that needs to be synthesized? */
4647 if (TREE_CODE (decl) == FUNCTION_DECL
4648 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl)
4649 && DECL_DEFAULTED_FN (decl)
4650 /* A function defaulted outside the class is synthesized either by
4651 cp_finish_decl or instantiate_decl. */
4652 && !DECL_DEFAULTED_OUTSIDE_CLASS_P (decl)
4653 && ! DECL_INITIAL (decl))
4654 {
4655 /* Defer virtual destructors so that thunks get the right
4656 linkage. */
4657 if (DECL_VIRTUAL_P (decl) && !at_eof)
4658 {
4659 note_vague_linkage_fn (decl);
4660 return true;
4661 }
4662
4663 /* Remember the current location for a function we will end up
4664 synthesizing. Then we can inform the user where it was
4665 required in the case of error. */
4666 DECL_SOURCE_LOCATION (decl) = input_location;
4667
4668 /* Synthesizing an implicitly defined member function will result in
4669 garbage collection. We must treat this situation as if we were
4670 within the body of a function so as to avoid collecting live data
4671 on the stack (such as overload resolution candidates).
4672
4673 We could just let cp_write_global_declarations handle synthesizing
4674 this function by adding it to deferred_fns, but doing
4675 it at the use site produces better error messages. */
4676 ++function_depth;
4677 synthesize_method (decl);
4678 --function_depth;
4679 /* If this is a synthesized method we don't need to
4680 do the instantiation test below. */
4681 }
4682 else if ((TREE_CODE (decl) == FUNCTION_DECL || TREE_CODE (decl) == VAR_DECL)
4683 && DECL_TEMPLATE_INFO (decl)
4684 && (!DECL_EXPLICIT_INSTANTIATION (decl)
4685 || always_instantiate_p (decl)))
4686 /* If this is a function or variable that is an instance of some
4687 template, we now know that we will need to actually do the
4688 instantiation. We check that DECL is not an explicit
4689 instantiation because that is not checked in instantiate_decl.
4690
4691 We put off instantiating functions in order to improve compile
4692 times. Maintaining a stack of active functions is expensive,
4693 and the inliner knows to instantiate any functions it might
4694 need. Therefore, we always try to defer instantiation. */
4695 {
4696 ++function_depth;
4697 instantiate_decl (decl, /*defer_ok=*/true,
4698 /*expl_inst_class_mem_p=*/false);
4699 --function_depth;
4700 }
4701
4702 return true;
4703 }
4704
4705 #include "gt-cp-decl2.h"
4706