1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions.
2 Copyright (C) 1987-2019 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com) and
4 modified by Brendan Kehoe (brendan@cygnus.com).
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
11 any later version.
12
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
21
22
23 /* High-level class interface. */
24
25 #include "config.h"
26 #include "system.h"
27 #include "coretypes.h"
28 #include "target.h"
29 #include "cp-tree.h"
30 #include "timevar.h"
31 #include "stringpool.h"
32 #include "cgraph.h"
33 #include "stor-layout.h"
34 #include "trans-mem.h"
35 #include "flags.h"
36 #include "toplev.h"
37 #include "intl.h"
38 #include "convert.h"
39 #include "langhooks.h"
40 #include "c-family/c-objc.h"
41 #include "internal-fn.h"
42 #include "stringpool.h"
43 #include "attribs.h"
44 #include "gcc-rich-location.h"
45
46 /* The various kinds of conversion. */
47
48 enum conversion_kind {
49 ck_identity,
50 ck_lvalue,
51 ck_fnptr,
52 ck_qual,
53 ck_std,
54 ck_ptr,
55 ck_pmem,
56 ck_base,
57 ck_ref_bind,
58 ck_user,
59 ck_ambig,
60 ck_list,
61 ck_aggr,
62 ck_rvalue
63 };
64
65 /* The rank of the conversion. Order of the enumerals matters; better
66 conversions should come earlier in the list. */
67
68 enum conversion_rank {
69 cr_identity,
70 cr_exact,
71 cr_promotion,
72 cr_std,
73 cr_pbool,
74 cr_user,
75 cr_ellipsis,
76 cr_bad
77 };
78
79 /* An implicit conversion sequence, in the sense of [over.best.ics].
80 The first conversion to be performed is at the end of the chain.
81 That conversion is always a cr_identity conversion. */
82
83 struct conversion {
84 /* The kind of conversion represented by this step. */
85 conversion_kind kind;
86 /* The rank of this conversion. */
87 conversion_rank rank;
88 BOOL_BITFIELD user_conv_p : 1;
89 BOOL_BITFIELD ellipsis_p : 1;
90 BOOL_BITFIELD this_p : 1;
91 /* True if this conversion would be permitted with a bending of
92 language standards, e.g. disregarding pointer qualifiers or
93 converting integers to pointers. */
94 BOOL_BITFIELD bad_p : 1;
95 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
96 temporary should be created to hold the result of the
97 conversion. If KIND is ck_ambig or ck_user, true means force
98 copy-initialization. */
99 BOOL_BITFIELD need_temporary_p : 1;
100 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
101 from a pointer-to-derived to pointer-to-base is being performed. */
102 BOOL_BITFIELD base_p : 1;
103 /* If KIND is ck_ref_bind, true when either an lvalue reference is
104 being bound to an lvalue expression or an rvalue reference is
105 being bound to an rvalue expression. If KIND is ck_rvalue or ck_base,
106 true when we are treating an lvalue as an rvalue (12.8p33). If
107 ck_identity, we will be binding a reference directly or decaying to
108 a pointer. */
109 BOOL_BITFIELD rvaluedness_matches_p: 1;
110 BOOL_BITFIELD check_narrowing: 1;
111 /* Whether check_narrowing should only check TREE_CONSTANTs; used
112 in build_converted_constant_expr. */
113 BOOL_BITFIELD check_narrowing_const_only: 1;
114 /* The type of the expression resulting from the conversion. */
115 tree type;
116 union {
117 /* The next conversion in the chain. Since the conversions are
118 arranged from outermost to innermost, the NEXT conversion will
119 actually be performed before this conversion. This variant is
120 used only when KIND is neither ck_identity, ck_ambig nor
121 ck_list. Please use the next_conversion function instead
122 of using this field directly. */
123 conversion *next;
124 /* The expression at the beginning of the conversion chain. This
125 variant is used only if KIND is ck_identity or ck_ambig. */
126 tree expr;
127 /* The array of conversions for an initializer_list, so this
128 variant is used only when KIN D is ck_list. */
129 conversion **list;
130 } u;
131 /* The function candidate corresponding to this conversion
132 sequence. This field is only used if KIND is ck_user. */
133 struct z_candidate *cand;
134 };
135
136 #define CONVERSION_RANK(NODE) \
137 ((NODE)->bad_p ? cr_bad \
138 : (NODE)->ellipsis_p ? cr_ellipsis \
139 : (NODE)->user_conv_p ? cr_user \
140 : (NODE)->rank)
141
142 #define BAD_CONVERSION_RANK(NODE) \
143 ((NODE)->ellipsis_p ? cr_ellipsis \
144 : (NODE)->user_conv_p ? cr_user \
145 : (NODE)->rank)
146
147 static struct obstack conversion_obstack;
148 static bool conversion_obstack_initialized;
149 struct rejection_reason;
150
151 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t);
152 static int equal_functions (tree, tree);
153 static int joust (struct z_candidate *, struct z_candidate *, bool,
154 tsubst_flags_t);
155 static int compare_ics (conversion *, conversion *);
156 static void maybe_warn_class_memaccess (location_t, tree,
157 const vec<tree, va_gc> *);
158 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
159 #define convert_like(CONV, EXPR, COMPLAIN) \
160 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \
161 /*issue_conversion_warnings=*/true, \
162 /*c_cast_p=*/false, (COMPLAIN))
163 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
164 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \
165 /*issue_conversion_warnings=*/true, \
166 /*c_cast_p=*/false, (COMPLAIN))
167 static tree convert_like_real (conversion *, tree, tree, int, bool,
168 bool, tsubst_flags_t);
169 static void op_error (const op_location_t &, enum tree_code, enum tree_code,
170 tree, tree, tree, bool);
171 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int,
172 tsubst_flags_t);
173 static void print_z_candidate (location_t, const char *, struct z_candidate *);
174 static void print_z_candidates (location_t, struct z_candidate *);
175 static tree build_this (tree);
176 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
177 static bool any_strictly_viable (struct z_candidate *);
178 static struct z_candidate *add_template_candidate
179 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
180 tree, tree, tree, int, unification_kind_t, tsubst_flags_t);
181 static struct z_candidate *add_template_candidate_real
182 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
183 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t);
184 static void add_builtin_candidates
185 (struct z_candidate **, enum tree_code, enum tree_code,
186 tree, tree *, int, tsubst_flags_t);
187 static void add_builtin_candidate
188 (struct z_candidate **, enum tree_code, enum tree_code,
189 tree, tree, tree, tree *, tree *, int, tsubst_flags_t);
190 static bool is_complete (tree);
191 static void build_builtin_candidate
192 (struct z_candidate **, tree, tree, tree, tree *, tree *,
193 int, tsubst_flags_t);
194 static struct z_candidate *add_conv_candidate
195 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, tree,
196 tree, tsubst_flags_t);
197 static struct z_candidate *add_function_candidate
198 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree,
199 tree, int, conversion**, tsubst_flags_t);
200 static conversion *implicit_conversion (tree, tree, tree, bool, int,
201 tsubst_flags_t);
202 static conversion *reference_binding (tree, tree, tree, bool, int,
203 tsubst_flags_t);
204 static conversion *build_conv (conversion_kind, tree, conversion *);
205 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t);
206 static conversion *next_conversion (conversion *);
207 static bool is_subseq (conversion *, conversion *);
208 static conversion *maybe_handle_ref_bind (conversion **);
209 static void maybe_handle_implicit_object (conversion **);
210 static struct z_candidate *add_candidate
211 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t,
212 conversion **, tree, tree, int, struct rejection_reason *, int);
213 static tree source_type (conversion *);
214 static void add_warning (struct z_candidate *, struct z_candidate *);
215 static bool reference_compatible_p (tree, tree);
216 static conversion *direct_reference_binding (tree, conversion *);
217 static bool promoted_arithmetic_type_p (tree);
218 static conversion *conditional_conversion (tree, tree, tsubst_flags_t);
219 static char *name_as_c_string (tree, tree, bool *);
220 static tree prep_operand (tree);
221 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree,
222 bool, tree, tree, int, struct z_candidate **,
223 tsubst_flags_t);
224 static conversion *merge_conversion_sequences (conversion *, conversion *);
225 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
226
227 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
228 NAME can take many forms... */
229
230 bool
check_dtor_name(tree basetype,tree name)231 check_dtor_name (tree basetype, tree name)
232 {
233 /* Just accept something we've already complained about. */
234 if (name == error_mark_node)
235 return true;
236
237 if (TREE_CODE (name) == TYPE_DECL)
238 name = TREE_TYPE (name);
239 else if (TYPE_P (name))
240 /* OK */;
241 else if (identifier_p (name))
242 {
243 if ((MAYBE_CLASS_TYPE_P (basetype)
244 || TREE_CODE (basetype) == ENUMERAL_TYPE)
245 && name == constructor_name (basetype))
246 return true;
247 else
248 name = get_type_value (name);
249 }
250 else
251 {
252 /* In the case of:
253
254 template <class T> struct S { ~S(); };
255 int i;
256 i.~S();
257
258 NAME will be a class template. */
259 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
260 return false;
261 }
262
263 if (!name || name == error_mark_node)
264 return false;
265 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
266 }
267
268 /* We want the address of a function or method. We avoid creating a
269 pointer-to-member function. */
270
271 tree
build_addr_func(tree function,tsubst_flags_t complain)272 build_addr_func (tree function, tsubst_flags_t complain)
273 {
274 tree type = TREE_TYPE (function);
275
276 /* We have to do these by hand to avoid real pointer to member
277 functions. */
278 if (TREE_CODE (type) == METHOD_TYPE)
279 {
280 if (TREE_CODE (function) == OFFSET_REF)
281 {
282 tree object = build_address (TREE_OPERAND (function, 0));
283 return get_member_function_from_ptrfunc (&object,
284 TREE_OPERAND (function, 1),
285 complain);
286 }
287 function = build_address (function);
288 }
289 else
290 function = decay_conversion (function, complain, /*reject_builtin=*/false);
291
292 return function;
293 }
294
295 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
296 POINTER_TYPE to those. Note, pointer to member function types
297 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
298 two variants. build_call_a is the primitive taking an array of
299 arguments, while build_call_n is a wrapper that handles varargs. */
300
301 tree
build_call_n(tree function,int n,...)302 build_call_n (tree function, int n, ...)
303 {
304 if (n == 0)
305 return build_call_a (function, 0, NULL);
306 else
307 {
308 tree *argarray = XALLOCAVEC (tree, n);
309 va_list ap;
310 int i;
311
312 va_start (ap, n);
313 for (i = 0; i < n; i++)
314 argarray[i] = va_arg (ap, tree);
315 va_end (ap);
316 return build_call_a (function, n, argarray);
317 }
318 }
319
320 /* Update various flags in cfun and the call itself based on what is being
321 called. Split out of build_call_a so that bot_manip can use it too. */
322
323 void
set_flags_from_callee(tree call)324 set_flags_from_callee (tree call)
325 {
326 /* Handle both CALL_EXPRs and AGGR_INIT_EXPRs. */
327 tree decl = cp_get_callee_fndecl_nofold (call);
328
329 /* We check both the decl and the type; a function may be known not to
330 throw without being declared throw(). */
331 bool nothrow = decl && TREE_NOTHROW (decl);
332 tree callee = cp_get_callee (call);
333 if (callee)
334 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (callee)));
335 else if (TREE_CODE (call) == CALL_EXPR
336 && internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW)
337 nothrow = true;
338
339 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain)
340 cp_function_chain->can_throw = 1;
341
342 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
343 current_function_returns_abnormally = 1;
344
345 TREE_NOTHROW (call) = nothrow;
346 }
347
348 tree
build_call_a(tree function,int n,tree * argarray)349 build_call_a (tree function, int n, tree *argarray)
350 {
351 tree decl;
352 tree result_type;
353 tree fntype;
354 int i;
355
356 function = build_addr_func (function, tf_warning_or_error);
357
358 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
359 fntype = TREE_TYPE (TREE_TYPE (function));
360 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
361 || TREE_CODE (fntype) == METHOD_TYPE);
362 result_type = TREE_TYPE (fntype);
363 /* An rvalue has no cv-qualifiers. */
364 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
365 result_type = cv_unqualified (result_type);
366
367 function = build_call_array_loc (input_location,
368 result_type, function, n, argarray);
369 set_flags_from_callee (function);
370
371 decl = get_callee_fndecl (function);
372
373 if (decl && !TREE_USED (decl))
374 {
375 /* We invoke build_call directly for several library
376 functions. These may have been declared normally if
377 we're building libgcc, so we can't just check
378 DECL_ARTIFICIAL. */
379 gcc_assert (DECL_ARTIFICIAL (decl)
380 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
381 "__", 2));
382 mark_used (decl);
383 }
384
385 require_complete_eh_spec_types (fntype, decl);
386
387 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl));
388
389 /* Don't pass empty class objects by value. This is useful
390 for tags in STL, which are used to control overload resolution.
391 We don't need to handle other cases of copying empty classes. */
392 if (!decl || !fndecl_built_in_p (decl))
393 for (i = 0; i < n; i++)
394 {
395 tree arg = CALL_EXPR_ARG (function, i);
396 if (is_empty_class (TREE_TYPE (arg))
397 && ! TREE_ADDRESSABLE (TREE_TYPE (arg)))
398 {
399 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg));
400 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t);
401 CALL_EXPR_ARG (function, i) = arg;
402 }
403 }
404
405 return function;
406 }
407
408 /* New overloading code. */
409
410 struct z_candidate;
411
412 struct candidate_warning {
413 z_candidate *loser;
414 candidate_warning *next;
415 };
416
417 /* Information for providing diagnostics about why overloading failed. */
418
419 enum rejection_reason_code {
420 rr_none,
421 rr_arity,
422 rr_explicit_conversion,
423 rr_template_conversion,
424 rr_arg_conversion,
425 rr_bad_arg_conversion,
426 rr_template_unification,
427 rr_invalid_copy,
428 rr_inherited_ctor,
429 rr_constraint_failure
430 };
431
432 struct conversion_info {
433 /* The index of the argument, 0-based. */
434 int n_arg;
435 /* The actual argument or its type. */
436 tree from;
437 /* The type of the parameter. */
438 tree to_type;
439 /* The location of the argument. */
440 location_t loc;
441 };
442
443 struct rejection_reason {
444 enum rejection_reason_code code;
445 union {
446 /* Information about an arity mismatch. */
447 struct {
448 /* The expected number of arguments. */
449 int expected;
450 /* The actual number of arguments in the call. */
451 int actual;
452 /* Whether the call was a varargs call. */
453 bool call_varargs_p;
454 } arity;
455 /* Information about an argument conversion mismatch. */
456 struct conversion_info conversion;
457 /* Same, but for bad argument conversions. */
458 struct conversion_info bad_conversion;
459 /* Information about template unification failures. These are the
460 parameters passed to fn_type_unification. */
461 struct {
462 tree tmpl;
463 tree explicit_targs;
464 int num_targs;
465 const tree *args;
466 unsigned int nargs;
467 tree return_type;
468 unification_kind_t strict;
469 int flags;
470 } template_unification;
471 /* Information about template instantiation failures. These are the
472 parameters passed to instantiate_template. */
473 struct {
474 tree tmpl;
475 tree targs;
476 } template_instantiation;
477 } u;
478 };
479
480 struct z_candidate {
481 /* The FUNCTION_DECL that will be called if this candidate is
482 selected by overload resolution. */
483 tree fn;
484 /* If not NULL_TREE, the first argument to use when calling this
485 function. */
486 tree first_arg;
487 /* The rest of the arguments to use when calling this function. If
488 there are no further arguments this may be NULL or it may be an
489 empty vector. */
490 const vec<tree, va_gc> *args;
491 /* The implicit conversion sequences for each of the arguments to
492 FN. */
493 conversion **convs;
494 /* The number of implicit conversion sequences. */
495 size_t num_convs;
496 /* If FN is a user-defined conversion, the standard conversion
497 sequence from the type returned by FN to the desired destination
498 type. */
499 conversion *second_conv;
500 struct rejection_reason *reason;
501 /* If FN is a member function, the binfo indicating the path used to
502 qualify the name of FN at the call site. This path is used to
503 determine whether or not FN is accessible if it is selected by
504 overload resolution. The DECL_CONTEXT of FN will always be a
505 (possibly improper) base of this binfo. */
506 tree access_path;
507 /* If FN is a non-static member function, the binfo indicating the
508 subobject to which the `this' pointer should be converted if FN
509 is selected by overload resolution. The type pointed to by
510 the `this' pointer must correspond to the most derived class
511 indicated by the CONVERSION_PATH. */
512 tree conversion_path;
513 tree template_decl;
514 tree explicit_targs;
515 candidate_warning *warnings;
516 z_candidate *next;
517 int viable;
518
519 /* The flags active in add_candidate. */
520 int flags;
521 };
522
523 /* Returns true iff T is a null pointer constant in the sense of
524 [conv.ptr]. */
525
526 bool
null_ptr_cst_p(tree t)527 null_ptr_cst_p (tree t)
528 {
529 tree type = TREE_TYPE (t);
530
531 /* [conv.ptr]
532
533 A null pointer constant is an integer literal ([lex.icon]) with value
534 zero or a prvalue of type std::nullptr_t. */
535 if (NULLPTR_TYPE_P (type))
536 return true;
537
538 if (cxx_dialect >= cxx11)
539 {
540 STRIP_ANY_LOCATION_WRAPPER (t);
541
542 /* Core issue 903 says only literal 0 is a null pointer constant. */
543 if (TREE_CODE (t) == INTEGER_CST
544 && !TREE_OVERFLOW (t)
545 && TREE_CODE (type) == INTEGER_TYPE
546 && integer_zerop (t)
547 && !char_type_p (type))
548 return true;
549 }
550 else if (CP_INTEGRAL_TYPE_P (type))
551 {
552 t = fold_non_dependent_expr (t, tf_none);
553 STRIP_NOPS (t);
554 if (integer_zerop (t) && !TREE_OVERFLOW (t))
555 return true;
556 }
557
558 return false;
559 }
560
561 /* Returns true iff T is a null member pointer value (4.11). */
562
563 bool
null_member_pointer_value_p(tree t)564 null_member_pointer_value_p (tree t)
565 {
566 tree type = TREE_TYPE (t);
567 if (!type)
568 return false;
569 else if (TYPE_PTRMEMFUNC_P (type))
570 return (TREE_CODE (t) == CONSTRUCTOR
571 && CONSTRUCTOR_NELTS (t)
572 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value));
573 else if (TYPE_PTRDATAMEM_P (type))
574 return integer_all_onesp (t);
575 else
576 return false;
577 }
578
579 /* Returns nonzero if PARMLIST consists of only default parms,
580 ellipsis, and/or undeduced parameter packs. */
581
582 bool
sufficient_parms_p(const_tree parmlist)583 sufficient_parms_p (const_tree parmlist)
584 {
585 for (; parmlist && parmlist != void_list_node;
586 parmlist = TREE_CHAIN (parmlist))
587 if (!TREE_PURPOSE (parmlist)
588 && !PACK_EXPANSION_P (TREE_VALUE (parmlist)))
589 return false;
590 return true;
591 }
592
593 /* Allocate N bytes of memory from the conversion obstack. The memory
594 is zeroed before being returned. */
595
596 static void *
conversion_obstack_alloc(size_t n)597 conversion_obstack_alloc (size_t n)
598 {
599 void *p;
600 if (!conversion_obstack_initialized)
601 {
602 gcc_obstack_init (&conversion_obstack);
603 conversion_obstack_initialized = true;
604 }
605 p = obstack_alloc (&conversion_obstack, n);
606 memset (p, 0, n);
607 return p;
608 }
609
610 /* Allocate rejection reasons. */
611
612 static struct rejection_reason *
alloc_rejection(enum rejection_reason_code code)613 alloc_rejection (enum rejection_reason_code code)
614 {
615 struct rejection_reason *p;
616 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
617 p->code = code;
618 return p;
619 }
620
621 static struct rejection_reason *
arity_rejection(tree first_arg,int expected,int actual)622 arity_rejection (tree first_arg, int expected, int actual)
623 {
624 struct rejection_reason *r = alloc_rejection (rr_arity);
625 int adjust = first_arg != NULL_TREE;
626 r->u.arity.expected = expected - adjust;
627 r->u.arity.actual = actual - adjust;
628 return r;
629 }
630
631 static struct rejection_reason *
arg_conversion_rejection(tree first_arg,int n_arg,tree from,tree to,location_t loc)632 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to,
633 location_t loc)
634 {
635 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
636 int adjust = first_arg != NULL_TREE;
637 r->u.conversion.n_arg = n_arg - adjust;
638 r->u.conversion.from = from;
639 r->u.conversion.to_type = to;
640 r->u.conversion.loc = loc;
641 return r;
642 }
643
644 static struct rejection_reason *
bad_arg_conversion_rejection(tree first_arg,int n_arg,tree from,tree to,location_t loc)645 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to,
646 location_t loc)
647 {
648 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
649 int adjust = first_arg != NULL_TREE;
650 r->u.bad_conversion.n_arg = n_arg - adjust;
651 r->u.bad_conversion.from = from;
652 r->u.bad_conversion.to_type = to;
653 r->u.bad_conversion.loc = loc;
654 return r;
655 }
656
657 static struct rejection_reason *
explicit_conversion_rejection(tree from,tree to)658 explicit_conversion_rejection (tree from, tree to)
659 {
660 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion);
661 r->u.conversion.n_arg = 0;
662 r->u.conversion.from = from;
663 r->u.conversion.to_type = to;
664 r->u.conversion.loc = UNKNOWN_LOCATION;
665 return r;
666 }
667
668 static struct rejection_reason *
template_conversion_rejection(tree from,tree to)669 template_conversion_rejection (tree from, tree to)
670 {
671 struct rejection_reason *r = alloc_rejection (rr_template_conversion);
672 r->u.conversion.n_arg = 0;
673 r->u.conversion.from = from;
674 r->u.conversion.to_type = to;
675 r->u.conversion.loc = UNKNOWN_LOCATION;
676 return r;
677 }
678
679 static struct rejection_reason *
template_unification_rejection(tree tmpl,tree explicit_targs,tree targs,const tree * args,unsigned int nargs,tree return_type,unification_kind_t strict,int flags)680 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs,
681 const tree *args, unsigned int nargs,
682 tree return_type, unification_kind_t strict,
683 int flags)
684 {
685 size_t args_n_bytes = sizeof (*args) * nargs;
686 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes);
687 struct rejection_reason *r = alloc_rejection (rr_template_unification);
688 r->u.template_unification.tmpl = tmpl;
689 r->u.template_unification.explicit_targs = explicit_targs;
690 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs);
691 /* Copy args to our own storage. */
692 memcpy (args1, args, args_n_bytes);
693 r->u.template_unification.args = args1;
694 r->u.template_unification.nargs = nargs;
695 r->u.template_unification.return_type = return_type;
696 r->u.template_unification.strict = strict;
697 r->u.template_unification.flags = flags;
698 return r;
699 }
700
701 static struct rejection_reason *
template_unification_error_rejection(void)702 template_unification_error_rejection (void)
703 {
704 return alloc_rejection (rr_template_unification);
705 }
706
707 static struct rejection_reason *
invalid_copy_with_fn_template_rejection(void)708 invalid_copy_with_fn_template_rejection (void)
709 {
710 struct rejection_reason *r = alloc_rejection (rr_invalid_copy);
711 return r;
712 }
713
714 static struct rejection_reason *
inherited_ctor_rejection(void)715 inherited_ctor_rejection (void)
716 {
717 struct rejection_reason *r = alloc_rejection (rr_inherited_ctor);
718 return r;
719 }
720
721 // Build a constraint failure record, saving information into the
722 // template_instantiation field of the rejection. If FN is not a template
723 // declaration, the TMPL member is the FN declaration and TARGS is empty.
724
725 static struct rejection_reason *
constraint_failure(tree fn)726 constraint_failure (tree fn)
727 {
728 struct rejection_reason *r = alloc_rejection (rr_constraint_failure);
729 if (tree ti = DECL_TEMPLATE_INFO (fn))
730 {
731 r->u.template_instantiation.tmpl = TI_TEMPLATE (ti);
732 r->u.template_instantiation.targs = TI_ARGS (ti);
733 }
734 else
735 {
736 r->u.template_instantiation.tmpl = fn;
737 r->u.template_instantiation.targs = NULL_TREE;
738 }
739 return r;
740 }
741
742 /* Dynamically allocate a conversion. */
743
744 static conversion *
alloc_conversion(conversion_kind kind)745 alloc_conversion (conversion_kind kind)
746 {
747 conversion *c;
748 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
749 c->kind = kind;
750 return c;
751 }
752
753 /* Make sure that all memory on the conversion obstack has been
754 freed. */
755
756 void
validate_conversion_obstack(void)757 validate_conversion_obstack (void)
758 {
759 if (conversion_obstack_initialized)
760 gcc_assert ((obstack_next_free (&conversion_obstack)
761 == obstack_base (&conversion_obstack)));
762 }
763
764 /* Dynamically allocate an array of N conversions. */
765
766 static conversion **
alloc_conversions(size_t n)767 alloc_conversions (size_t n)
768 {
769 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
770 }
771
772 static conversion *
build_conv(conversion_kind code,tree type,conversion * from)773 build_conv (conversion_kind code, tree type, conversion *from)
774 {
775 conversion *t;
776 conversion_rank rank = CONVERSION_RANK (from);
777
778 /* Note that the caller is responsible for filling in t->cand for
779 user-defined conversions. */
780 t = alloc_conversion (code);
781 t->type = type;
782 t->u.next = from;
783
784 switch (code)
785 {
786 case ck_ptr:
787 case ck_pmem:
788 case ck_base:
789 case ck_std:
790 if (rank < cr_std)
791 rank = cr_std;
792 break;
793
794 case ck_qual:
795 case ck_fnptr:
796 if (rank < cr_exact)
797 rank = cr_exact;
798 break;
799
800 default:
801 break;
802 }
803 t->rank = rank;
804 t->user_conv_p = (code == ck_user || from->user_conv_p);
805 t->bad_p = from->bad_p;
806 t->base_p = false;
807 return t;
808 }
809
810 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
811 specialization of std::initializer_list<T>, if such a conversion is
812 possible. */
813
814 static conversion *
build_list_conv(tree type,tree ctor,int flags,tsubst_flags_t complain)815 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
816 {
817 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
818 unsigned len = CONSTRUCTOR_NELTS (ctor);
819 conversion **subconvs = alloc_conversions (len);
820 conversion *t;
821 unsigned i;
822 tree val;
823
824 /* Within a list-initialization we can have more user-defined
825 conversions. */
826 flags &= ~LOOKUP_NO_CONVERSION;
827 /* But no narrowing conversions. */
828 flags |= LOOKUP_NO_NARROWING;
829
830 /* Can't make an array of these types. */
831 if (TYPE_REF_P (elttype)
832 || TREE_CODE (elttype) == FUNCTION_TYPE
833 || VOID_TYPE_P (elttype))
834 return NULL;
835
836 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
837 {
838 conversion *sub
839 = implicit_conversion (elttype, TREE_TYPE (val), val,
840 false, flags, complain);
841 if (sub == NULL)
842 return NULL;
843
844 subconvs[i] = sub;
845 }
846
847 t = alloc_conversion (ck_list);
848 t->type = type;
849 t->u.list = subconvs;
850 t->rank = cr_exact;
851
852 for (i = 0; i < len; ++i)
853 {
854 conversion *sub = subconvs[i];
855 if (sub->rank > t->rank)
856 t->rank = sub->rank;
857 if (sub->user_conv_p)
858 t->user_conv_p = true;
859 if (sub->bad_p)
860 t->bad_p = true;
861 }
862
863 return t;
864 }
865
866 /* Return the next conversion of the conversion chain (if applicable),
867 or NULL otherwise. Please use this function instead of directly
868 accessing fields of struct conversion. */
869
870 static conversion *
next_conversion(conversion * conv)871 next_conversion (conversion *conv)
872 {
873 if (conv == NULL
874 || conv->kind == ck_identity
875 || conv->kind == ck_ambig
876 || conv->kind == ck_list)
877 return NULL;
878 return conv->u.next;
879 }
880
881 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
882 is a valid aggregate initializer for array type ATYPE. */
883
884 static bool
can_convert_array(tree atype,tree ctor,int flags,tsubst_flags_t complain)885 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain)
886 {
887 unsigned i;
888 tree elttype = TREE_TYPE (atype);
889 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
890 {
891 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
892 bool ok;
893 if (TREE_CODE (elttype) == ARRAY_TYPE
894 && TREE_CODE (val) == CONSTRUCTOR)
895 ok = can_convert_array (elttype, val, flags, complain);
896 else
897 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags,
898 complain);
899 if (!ok)
900 return false;
901 }
902 return true;
903 }
904
905 /* Helper for build_aggr_conv. Return true if FIELD is in PSET, or if
906 FIELD has ANON_AGGR_TYPE_P and any initializable field in there recursively
907 is in PSET. */
908
909 static bool
field_in_pset(hash_set<tree,true> & pset,tree field)910 field_in_pset (hash_set<tree, true> &pset, tree field)
911 {
912 if (pset.contains (field))
913 return true;
914 if (ANON_AGGR_TYPE_P (TREE_TYPE (field)))
915 for (field = TYPE_FIELDS (TREE_TYPE (field));
916 field; field = DECL_CHAIN (field))
917 {
918 field = next_initializable_field (field);
919 if (field == NULL_TREE)
920 break;
921 if (field_in_pset (pset, field))
922 return true;
923 }
924 return false;
925 }
926
927 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
928 aggregate class, if such a conversion is possible. */
929
930 static conversion *
build_aggr_conv(tree type,tree ctor,int flags,tsubst_flags_t complain)931 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
932 {
933 unsigned HOST_WIDE_INT i = 0;
934 conversion *c;
935 tree field = next_initializable_field (TYPE_FIELDS (type));
936 tree empty_ctor = NULL_TREE;
937 hash_set<tree, true> pset;
938
939 /* We already called reshape_init in implicit_conversion. */
940
941 /* The conversions within the init-list aren't affected by the enclosing
942 context; they're always simple copy-initialization. */
943 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
944
945 /* For designated initializers, verify that each initializer is convertible
946 to corresponding TREE_TYPE (ce->index) and mark those FIELD_DECLs as
947 visited. In the following loop then ignore already visited
948 FIELD_DECLs. */
949 if (CONSTRUCTOR_IS_DESIGNATED_INIT (ctor))
950 {
951 tree idx, val;
952 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), i, idx, val)
953 {
954 if (idx && TREE_CODE (idx) == FIELD_DECL)
955 {
956 tree ftype = TREE_TYPE (idx);
957 bool ok;
958
959 if (TREE_CODE (ftype) == ARRAY_TYPE
960 && TREE_CODE (val) == CONSTRUCTOR)
961 ok = can_convert_array (ftype, val, flags, complain);
962 else
963 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags,
964 complain);
965
966 if (!ok)
967 return NULL;
968 /* For unions, there should be just one initializer. */
969 if (TREE_CODE (type) == UNION_TYPE)
970 {
971 field = NULL_TREE;
972 i = 1;
973 break;
974 }
975 pset.add (idx);
976 }
977 else
978 return NULL;
979 }
980 }
981
982 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
983 {
984 tree ftype = TREE_TYPE (field);
985 tree val;
986 bool ok;
987
988 if (pset.elements () && field_in_pset (pset, field))
989 continue;
990 if (i < CONSTRUCTOR_NELTS (ctor))
991 {
992 val = CONSTRUCTOR_ELT (ctor, i)->value;
993 ++i;
994 }
995 else if (DECL_INITIAL (field))
996 val = get_nsdmi (field, /*ctor*/false, complain);
997 else if (TYPE_REF_P (ftype))
998 /* Value-initialization of reference is ill-formed. */
999 return NULL;
1000 else
1001 {
1002 if (empty_ctor == NULL_TREE)
1003 empty_ctor = build_constructor (init_list_type_node, NULL);
1004 val = empty_ctor;
1005 }
1006
1007 if (TREE_CODE (ftype) == ARRAY_TYPE
1008 && TREE_CODE (val) == CONSTRUCTOR)
1009 ok = can_convert_array (ftype, val, flags, complain);
1010 else
1011 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags,
1012 complain);
1013
1014 if (!ok)
1015 return NULL;
1016
1017 if (TREE_CODE (type) == UNION_TYPE)
1018 break;
1019 }
1020
1021 if (i < CONSTRUCTOR_NELTS (ctor))
1022 return NULL;
1023
1024 c = alloc_conversion (ck_aggr);
1025 c->type = type;
1026 c->rank = cr_exact;
1027 c->user_conv_p = true;
1028 c->check_narrowing = true;
1029 c->u.next = NULL;
1030 return c;
1031 }
1032
1033 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
1034 array type, if such a conversion is possible. */
1035
1036 static conversion *
build_array_conv(tree type,tree ctor,int flags,tsubst_flags_t complain)1037 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
1038 {
1039 conversion *c;
1040 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
1041 tree elttype = TREE_TYPE (type);
1042 unsigned i;
1043 tree val;
1044 bool bad = false;
1045 bool user = false;
1046 enum conversion_rank rank = cr_exact;
1047
1048 /* We might need to propagate the size from the element to the array. */
1049 complete_type (type);
1050
1051 if (TYPE_DOMAIN (type)
1052 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE))
1053 {
1054 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type));
1055 if (alen < len)
1056 return NULL;
1057 }
1058
1059 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
1060
1061 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
1062 {
1063 conversion *sub
1064 = implicit_conversion (elttype, TREE_TYPE (val), val,
1065 false, flags, complain);
1066 if (sub == NULL)
1067 return NULL;
1068
1069 if (sub->rank > rank)
1070 rank = sub->rank;
1071 if (sub->user_conv_p)
1072 user = true;
1073 if (sub->bad_p)
1074 bad = true;
1075 }
1076
1077 c = alloc_conversion (ck_aggr);
1078 c->type = type;
1079 c->rank = rank;
1080 c->user_conv_p = user;
1081 c->bad_p = bad;
1082 c->u.next = NULL;
1083 return c;
1084 }
1085
1086 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
1087 complex type, if such a conversion is possible. */
1088
1089 static conversion *
build_complex_conv(tree type,tree ctor,int flags,tsubst_flags_t complain)1090 build_complex_conv (tree type, tree ctor, int flags,
1091 tsubst_flags_t complain)
1092 {
1093 conversion *c;
1094 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
1095 tree elttype = TREE_TYPE (type);
1096 unsigned i;
1097 tree val;
1098 bool bad = false;
1099 bool user = false;
1100 enum conversion_rank rank = cr_exact;
1101
1102 if (len != 2)
1103 return NULL;
1104
1105 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
1106
1107 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
1108 {
1109 conversion *sub
1110 = implicit_conversion (elttype, TREE_TYPE (val), val,
1111 false, flags, complain);
1112 if (sub == NULL)
1113 return NULL;
1114
1115 if (sub->rank > rank)
1116 rank = sub->rank;
1117 if (sub->user_conv_p)
1118 user = true;
1119 if (sub->bad_p)
1120 bad = true;
1121 }
1122
1123 c = alloc_conversion (ck_aggr);
1124 c->type = type;
1125 c->rank = rank;
1126 c->user_conv_p = user;
1127 c->bad_p = bad;
1128 c->u.next = NULL;
1129 return c;
1130 }
1131
1132 /* Build a representation of the identity conversion from EXPR to
1133 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
1134
1135 static conversion *
build_identity_conv(tree type,tree expr)1136 build_identity_conv (tree type, tree expr)
1137 {
1138 conversion *c;
1139
1140 c = alloc_conversion (ck_identity);
1141 c->type = type;
1142 c->u.expr = expr;
1143
1144 return c;
1145 }
1146
1147 /* Converting from EXPR to TYPE was ambiguous in the sense that there
1148 were multiple user-defined conversions to accomplish the job.
1149 Build a conversion that indicates that ambiguity. */
1150
1151 static conversion *
build_ambiguous_conv(tree type,tree expr)1152 build_ambiguous_conv (tree type, tree expr)
1153 {
1154 conversion *c;
1155
1156 c = alloc_conversion (ck_ambig);
1157 c->type = type;
1158 c->u.expr = expr;
1159
1160 return c;
1161 }
1162
1163 tree
strip_top_quals(tree t)1164 strip_top_quals (tree t)
1165 {
1166 if (TREE_CODE (t) == ARRAY_TYPE)
1167 return t;
1168 return cp_build_qualified_type (t, 0);
1169 }
1170
1171 /* Returns the standard conversion path (see [conv]) from type FROM to type
1172 TO, if any. For proper handling of null pointer constants, you must
1173 also pass the expression EXPR to convert from. If C_CAST_P is true,
1174 this conversion is coming from a C-style cast. */
1175
1176 static conversion *
standard_conversion(tree to,tree from,tree expr,bool c_cast_p,int flags,tsubst_flags_t complain)1177 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
1178 int flags, tsubst_flags_t complain)
1179 {
1180 enum tree_code fcode, tcode;
1181 conversion *conv;
1182 bool fromref = false;
1183 tree qualified_to;
1184
1185 to = non_reference (to);
1186 if (TYPE_REF_P (from))
1187 {
1188 fromref = true;
1189 from = TREE_TYPE (from);
1190 }
1191 qualified_to = to;
1192 to = strip_top_quals (to);
1193 from = strip_top_quals (from);
1194
1195 if (expr && type_unknown_p (expr))
1196 {
1197 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
1198 {
1199 tsubst_flags_t tflags = tf_conv;
1200 expr = instantiate_type (to, expr, tflags);
1201 if (expr == error_mark_node)
1202 return NULL;
1203 from = TREE_TYPE (expr);
1204 }
1205 else if (TREE_CODE (to) == BOOLEAN_TYPE)
1206 {
1207 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */
1208 expr = resolve_nondeduced_context (expr, complain);
1209 from = TREE_TYPE (expr);
1210 }
1211 }
1212
1213 fcode = TREE_CODE (from);
1214 tcode = TREE_CODE (to);
1215
1216 conv = build_identity_conv (from, expr);
1217 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
1218 {
1219 from = type_decays_to (from);
1220 fcode = TREE_CODE (from);
1221 /* Tell convert_like_real that we're using the address. */
1222 conv->rvaluedness_matches_p = true;
1223 conv = build_conv (ck_lvalue, from, conv);
1224 }
1225 /* Wrapping a ck_rvalue around a class prvalue (as a result of using
1226 obvalue_p) seems odd, since it's already a prvalue, but that's how we
1227 express the copy constructor call required by copy-initialization. */
1228 else if (fromref || (expr && obvalue_p (expr)))
1229 {
1230 if (expr)
1231 {
1232 tree bitfield_type;
1233 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
1234 if (bitfield_type)
1235 {
1236 from = strip_top_quals (bitfield_type);
1237 fcode = TREE_CODE (from);
1238 }
1239 }
1240 conv = build_conv (ck_rvalue, from, conv);
1241 if (flags & LOOKUP_PREFER_RVALUE)
1242 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */
1243 conv->rvaluedness_matches_p = true;
1244 }
1245
1246 /* Allow conversion between `__complex__' data types. */
1247 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
1248 {
1249 /* The standard conversion sequence to convert FROM to TO is
1250 the standard conversion sequence to perform componentwise
1251 conversion. */
1252 conversion *part_conv = standard_conversion
1253 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags,
1254 complain);
1255
1256 if (part_conv)
1257 {
1258 conv = build_conv (part_conv->kind, to, conv);
1259 conv->rank = part_conv->rank;
1260 }
1261 else
1262 conv = NULL;
1263
1264 return conv;
1265 }
1266
1267 if (same_type_p (from, to))
1268 {
1269 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
1270 conv->type = qualified_to;
1271 return conv;
1272 }
1273
1274 /* [conv.ptr]
1275 A null pointer constant can be converted to a pointer type; ... A
1276 null pointer constant of integral type can be converted to an
1277 rvalue of type std::nullptr_t. */
1278 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to)
1279 || NULLPTR_TYPE_P (to))
1280 && ((expr && null_ptr_cst_p (expr))
1281 || NULLPTR_TYPE_P (from)))
1282 conv = build_conv (ck_std, to, conv);
1283 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
1284 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
1285 {
1286 /* For backwards brain damage compatibility, allow interconversion of
1287 pointers and integers with a pedwarn. */
1288 conv = build_conv (ck_std, to, conv);
1289 conv->bad_p = true;
1290 }
1291 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
1292 {
1293 /* For backwards brain damage compatibility, allow interconversion of
1294 enums and integers with a pedwarn. */
1295 conv = build_conv (ck_std, to, conv);
1296 conv->bad_p = true;
1297 }
1298 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1299 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from)))
1300 {
1301 tree to_pointee;
1302 tree from_pointee;
1303
1304 if (tcode == POINTER_TYPE)
1305 {
1306 to_pointee = TREE_TYPE (to);
1307 from_pointee = TREE_TYPE (from);
1308
1309 /* Since this is the target of a pointer, it can't have function
1310 qualifiers, so any TYPE_QUALS must be for attributes const or
1311 noreturn. Strip them. */
1312 if (TREE_CODE (to_pointee) == FUNCTION_TYPE
1313 && TYPE_QUALS (to_pointee))
1314 to_pointee = build_qualified_type (to_pointee, TYPE_UNQUALIFIED);
1315 if (TREE_CODE (from_pointee) == FUNCTION_TYPE
1316 && TYPE_QUALS (from_pointee))
1317 from_pointee = build_qualified_type (from_pointee, TYPE_UNQUALIFIED);
1318 }
1319 else
1320 {
1321 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1322 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1323 }
1324
1325 if (tcode == POINTER_TYPE
1326 && same_type_ignoring_top_level_qualifiers_p (from_pointee,
1327 to_pointee))
1328 ;
1329 else if (VOID_TYPE_P (to_pointee)
1330 && !TYPE_PTRDATAMEM_P (from)
1331 && TREE_CODE (from_pointee) != FUNCTION_TYPE)
1332 {
1333 tree nfrom = TREE_TYPE (from);
1334 /* Don't try to apply restrict to void. */
1335 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT;
1336 from_pointee = cp_build_qualified_type (void_type_node, quals);
1337 from = build_pointer_type (from_pointee);
1338 conv = build_conv (ck_ptr, from, conv);
1339 }
1340 else if (TYPE_PTRDATAMEM_P (from))
1341 {
1342 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1343 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1344
1345 if (same_type_p (fbase, tbase))
1346 /* No base conversion needed. */;
1347 else if (DERIVED_FROM_P (fbase, tbase)
1348 && (same_type_ignoring_top_level_qualifiers_p
1349 (from_pointee, to_pointee)))
1350 {
1351 from = build_ptrmem_type (tbase, from_pointee);
1352 conv = build_conv (ck_pmem, from, conv);
1353 }
1354 else
1355 return NULL;
1356 }
1357 else if (CLASS_TYPE_P (from_pointee)
1358 && CLASS_TYPE_P (to_pointee)
1359 /* [conv.ptr]
1360
1361 An rvalue of type "pointer to cv D," where D is a
1362 class type, can be converted to an rvalue of type
1363 "pointer to cv B," where B is a base class (clause
1364 _class.derived_) of D. If B is an inaccessible
1365 (clause _class.access_) or ambiguous
1366 (_class.member.lookup_) base class of D, a program
1367 that necessitates this conversion is ill-formed.
1368 Therefore, we use DERIVED_FROM_P, and do not check
1369 access or uniqueness. */
1370 && DERIVED_FROM_P (to_pointee, from_pointee))
1371 {
1372 from_pointee
1373 = cp_build_qualified_type (to_pointee,
1374 cp_type_quals (from_pointee));
1375 from = build_pointer_type (from_pointee);
1376 conv = build_conv (ck_ptr, from, conv);
1377 conv->base_p = true;
1378 }
1379
1380 if (same_type_p (from, to))
1381 /* OK */;
1382 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1383 /* In a C-style cast, we ignore CV-qualification because we
1384 are allowed to perform a static_cast followed by a
1385 const_cast. */
1386 conv = build_conv (ck_qual, to, conv);
1387 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1388 conv = build_conv (ck_qual, to, conv);
1389 else if (expr && string_conv_p (to, expr, 0))
1390 /* converting from string constant to char *. */
1391 conv = build_conv (ck_qual, to, conv);
1392 else if (fnptr_conv_p (to, from))
1393 conv = build_conv (ck_fnptr, to, conv);
1394 /* Allow conversions among compatible ObjC pointer types (base
1395 conversions have been already handled above). */
1396 else if (c_dialect_objc ()
1397 && objc_compare_types (to, from, -4, NULL_TREE))
1398 conv = build_conv (ck_ptr, to, conv);
1399 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1400 {
1401 conv = build_conv (ck_ptr, to, conv);
1402 conv->bad_p = true;
1403 }
1404 else
1405 return NULL;
1406
1407 from = to;
1408 }
1409 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1410 {
1411 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1412 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1413 tree fbase = class_of_this_parm (fromfn);
1414 tree tbase = class_of_this_parm (tofn);
1415
1416 if (!DERIVED_FROM_P (fbase, tbase))
1417 return NULL;
1418
1419 tree fstat = static_fn_type (fromfn);
1420 tree tstat = static_fn_type (tofn);
1421 if (same_type_p (tstat, fstat)
1422 || fnptr_conv_p (tstat, fstat))
1423 /* OK */;
1424 else
1425 return NULL;
1426
1427 if (!same_type_p (fbase, tbase))
1428 {
1429 from = build_memfn_type (fstat,
1430 tbase,
1431 cp_type_quals (tbase),
1432 type_memfn_rqual (tofn));
1433 from = build_ptrmemfunc_type (build_pointer_type (from));
1434 conv = build_conv (ck_pmem, from, conv);
1435 conv->base_p = true;
1436 }
1437 if (fnptr_conv_p (tstat, fstat))
1438 conv = build_conv (ck_fnptr, to, conv);
1439 }
1440 else if (tcode == BOOLEAN_TYPE)
1441 {
1442 /* [conv.bool]
1443
1444 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer
1445 to member type can be converted to a prvalue of type bool. ...
1446 For direct-initialization (8.5 [dcl.init]), a prvalue of type
1447 std::nullptr_t can be converted to a prvalue of type bool; */
1448 if (ARITHMETIC_TYPE_P (from)
1449 || UNSCOPED_ENUM_P (from)
1450 || fcode == POINTER_TYPE
1451 || TYPE_PTRMEM_P (from)
1452 || NULLPTR_TYPE_P (from))
1453 {
1454 conv = build_conv (ck_std, to, conv);
1455 if (fcode == POINTER_TYPE
1456 || TYPE_PTRDATAMEM_P (from)
1457 || (TYPE_PTRMEMFUNC_P (from)
1458 && conv->rank < cr_pbool)
1459 || NULLPTR_TYPE_P (from))
1460 conv->rank = cr_pbool;
1461 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING))
1462 conv->bad_p = true;
1463 if (flags & LOOKUP_NO_NARROWING)
1464 conv->check_narrowing = true;
1465 return conv;
1466 }
1467
1468 return NULL;
1469 }
1470 /* We don't check for ENUMERAL_TYPE here because there are no standard
1471 conversions to enum type. */
1472 /* As an extension, allow conversion to complex type. */
1473 else if (ARITHMETIC_TYPE_P (to))
1474 {
1475 if (! (INTEGRAL_CODE_P (fcode)
1476 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL)))
1477 || SCOPED_ENUM_P (from))
1478 return NULL;
1479
1480 /* If we're parsing an enum with no fixed underlying type, we're
1481 dealing with an incomplete type, which renders the conversion
1482 ill-formed. */
1483 if (!COMPLETE_TYPE_P (from))
1484 return NULL;
1485
1486 conv = build_conv (ck_std, to, conv);
1487
1488 /* Give this a better rank if it's a promotion. */
1489 if (same_type_p (to, type_promotes_to (from))
1490 && next_conversion (conv)->rank <= cr_promotion)
1491 conv->rank = cr_promotion;
1492 }
1493 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1494 && vector_types_convertible_p (from, to, false))
1495 return build_conv (ck_std, to, conv);
1496 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1497 && is_properly_derived_from (from, to))
1498 {
1499 if (conv->kind == ck_rvalue)
1500 conv = next_conversion (conv);
1501 conv = build_conv (ck_base, to, conv);
1502 /* The derived-to-base conversion indicates the initialization
1503 of a parameter with base type from an object of a derived
1504 type. A temporary object is created to hold the result of
1505 the conversion unless we're binding directly to a reference. */
1506 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1507 if (flags & LOOKUP_PREFER_RVALUE)
1508 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */
1509 conv->rvaluedness_matches_p = true;
1510 }
1511 else
1512 return NULL;
1513
1514 if (flags & LOOKUP_NO_NARROWING)
1515 conv->check_narrowing = true;
1516
1517 return conv;
1518 }
1519
1520 /* Returns nonzero if T1 is reference-related to T2. */
1521
1522 bool
reference_related_p(tree t1,tree t2)1523 reference_related_p (tree t1, tree t2)
1524 {
1525 if (t1 == error_mark_node || t2 == error_mark_node)
1526 return false;
1527
1528 t1 = TYPE_MAIN_VARIANT (t1);
1529 t2 = TYPE_MAIN_VARIANT (t2);
1530
1531 /* [dcl.init.ref]
1532
1533 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1534 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1535 of T2. */
1536 return (same_type_p (t1, t2)
1537 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1538 && DERIVED_FROM_P (t1, t2)));
1539 }
1540
1541 /* Returns nonzero if T1 is reference-compatible with T2. */
1542
1543 static bool
reference_compatible_p(tree t1,tree t2)1544 reference_compatible_p (tree t1, tree t2)
1545 {
1546 /* [dcl.init.ref]
1547
1548 "cv1 T1" is reference compatible with "cv2 T2" if
1549 * T1 is reference-related to T2 or
1550 * T2 is "noexcept function" and T1 is "function", where the
1551 function types are otherwise the same,
1552 and cv1 is the same cv-qualification as, or greater cv-qualification
1553 than, cv2. */
1554 return ((reference_related_p (t1, t2)
1555 || fnptr_conv_p (t1, t2))
1556 && at_least_as_qualified_p (t1, t2));
1557 }
1558
1559 /* A reference of the indicated TYPE is being bound directly to the
1560 expression represented by the implicit conversion sequence CONV.
1561 Return a conversion sequence for this binding. */
1562
1563 static conversion *
direct_reference_binding(tree type,conversion * conv)1564 direct_reference_binding (tree type, conversion *conv)
1565 {
1566 tree t;
1567
1568 gcc_assert (TYPE_REF_P (type));
1569 gcc_assert (!TYPE_REF_P (conv->type));
1570
1571 t = TREE_TYPE (type);
1572
1573 if (conv->kind == ck_identity)
1574 /* Mark the identity conv as to not decay to rvalue. */
1575 conv->rvaluedness_matches_p = true;
1576
1577 /* [over.ics.rank]
1578
1579 When a parameter of reference type binds directly
1580 (_dcl.init.ref_) to an argument expression, the implicit
1581 conversion sequence is the identity conversion, unless the
1582 argument expression has a type that is a derived class of the
1583 parameter type, in which case the implicit conversion sequence is
1584 a derived-to-base Conversion.
1585
1586 If the parameter binds directly to the result of applying a
1587 conversion function to the argument expression, the implicit
1588 conversion sequence is a user-defined conversion sequence
1589 (_over.ics.user_), with the second standard conversion sequence
1590 either an identity conversion or, if the conversion function
1591 returns an entity of a type that is a derived class of the
1592 parameter type, a derived-to-base conversion. */
1593 if (is_properly_derived_from (conv->type, t))
1594 {
1595 /* Represent the derived-to-base conversion. */
1596 conv = build_conv (ck_base, t, conv);
1597 /* We will actually be binding to the base-class subobject in
1598 the derived class, so we mark this conversion appropriately.
1599 That way, convert_like knows not to generate a temporary. */
1600 conv->need_temporary_p = false;
1601 }
1602
1603 return build_conv (ck_ref_bind, type, conv);
1604 }
1605
1606 /* Returns the conversion path from type FROM to reference type TO for
1607 purposes of reference binding. For lvalue binding, either pass a
1608 reference type to FROM or an lvalue expression to EXPR. If the
1609 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1610 the conversion returned. If C_CAST_P is true, this
1611 conversion is coming from a C-style cast. */
1612
1613 static conversion *
reference_binding(tree rto,tree rfrom,tree expr,bool c_cast_p,int flags,tsubst_flags_t complain)1614 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags,
1615 tsubst_flags_t complain)
1616 {
1617 conversion *conv = NULL;
1618 tree to = TREE_TYPE (rto);
1619 tree from = rfrom;
1620 tree tfrom;
1621 bool related_p;
1622 bool compatible_p;
1623 cp_lvalue_kind gl_kind;
1624 bool is_lvalue;
1625
1626 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1627 {
1628 expr = instantiate_type (to, expr, tf_none);
1629 if (expr == error_mark_node)
1630 return NULL;
1631 from = TREE_TYPE (expr);
1632 }
1633
1634 bool copy_list_init = false;
1635 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1636 {
1637 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1638 /* DR 1288: Otherwise, if the initializer list has a single element
1639 of type E and ... [T's] referenced type is reference-related to E,
1640 the object or reference is initialized from that element... */
1641 if (CONSTRUCTOR_NELTS (expr) == 1)
1642 {
1643 tree elt = CONSTRUCTOR_ELT (expr, 0)->value;
1644 if (error_operand_p (elt))
1645 return NULL;
1646 tree etype = TREE_TYPE (elt);
1647 if (reference_related_p (to, etype))
1648 {
1649 expr = elt;
1650 from = etype;
1651 goto skip;
1652 }
1653 }
1654 /* Otherwise, if T is a reference type, a prvalue temporary of the type
1655 referenced by T is copy-list-initialized, and the reference is bound
1656 to that temporary. */
1657 copy_list_init = true;
1658 skip:;
1659 }
1660
1661 if (TYPE_REF_P (from))
1662 {
1663 from = TREE_TYPE (from);
1664 if (!TYPE_REF_IS_RVALUE (rfrom)
1665 || TREE_CODE (from) == FUNCTION_TYPE)
1666 gl_kind = clk_ordinary;
1667 else
1668 gl_kind = clk_rvalueref;
1669 }
1670 else if (expr)
1671 gl_kind = lvalue_kind (expr);
1672 else if (CLASS_TYPE_P (from)
1673 || TREE_CODE (from) == ARRAY_TYPE)
1674 gl_kind = clk_class;
1675 else
1676 gl_kind = clk_none;
1677
1678 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */
1679 if ((flags & LOOKUP_NO_TEMP_BIND)
1680 && (gl_kind & clk_class))
1681 gl_kind = clk_none;
1682
1683 /* Same mask as real_lvalue_p. */
1684 is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class));
1685
1686 tfrom = from;
1687 if ((gl_kind & clk_bitfield) != 0)
1688 tfrom = unlowered_expr_type (expr);
1689
1690 /* Figure out whether or not the types are reference-related and
1691 reference compatible. We have to do this after stripping
1692 references from FROM. */
1693 related_p = reference_related_p (to, tfrom);
1694 /* If this is a C cast, first convert to an appropriately qualified
1695 type, so that we can later do a const_cast to the desired type. */
1696 if (related_p && c_cast_p
1697 && !at_least_as_qualified_p (to, tfrom))
1698 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1699 compatible_p = reference_compatible_p (to, tfrom);
1700
1701 /* Directly bind reference when target expression's type is compatible with
1702 the reference and expression is an lvalue. In DR391, the wording in
1703 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1704 const and rvalue references to rvalues of compatible class type.
1705 We should also do direct bindings for non-class xvalues. */
1706 if ((related_p || compatible_p) && gl_kind)
1707 {
1708 /* [dcl.init.ref]
1709
1710 If the initializer expression
1711
1712 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1713 is reference-compatible with "cv2 T2,"
1714
1715 the reference is bound directly to the initializer expression
1716 lvalue.
1717
1718 [...]
1719 If the initializer expression is an rvalue, with T2 a class type,
1720 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1721 is bound to the object represented by the rvalue or to a sub-object
1722 within that object. */
1723
1724 conv = build_identity_conv (tfrom, expr);
1725 conv = direct_reference_binding (rto, conv);
1726
1727 if (TYPE_REF_P (rfrom))
1728 /* Handle rvalue reference to function properly. */
1729 conv->rvaluedness_matches_p
1730 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom));
1731 else
1732 conv->rvaluedness_matches_p
1733 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1734
1735 if ((gl_kind & clk_bitfield) != 0
1736 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to)))
1737 /* For the purposes of overload resolution, we ignore the fact
1738 this expression is a bitfield or packed field. (In particular,
1739 [over.ics.ref] says specifically that a function with a
1740 non-const reference parameter is viable even if the
1741 argument is a bitfield.)
1742
1743 However, when we actually call the function we must create
1744 a temporary to which to bind the reference. If the
1745 reference is volatile, or isn't const, then we cannot make
1746 a temporary, so we just issue an error when the conversion
1747 actually occurs. */
1748 conv->need_temporary_p = true;
1749
1750 /* Don't allow binding of lvalues (other than function lvalues) to
1751 rvalue references. */
1752 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1753 && TREE_CODE (to) != FUNCTION_TYPE)
1754 conv->bad_p = true;
1755
1756 /* Nor the reverse. */
1757 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto)
1758 && (!CP_TYPE_CONST_NON_VOLATILE_P (to)
1759 || (flags & LOOKUP_NO_RVAL_BIND))
1760 && TREE_CODE (to) != FUNCTION_TYPE)
1761 conv->bad_p = true;
1762
1763 if (!compatible_p)
1764 conv->bad_p = true;
1765
1766 return conv;
1767 }
1768 /* [class.conv.fct] A conversion function is never used to convert a
1769 (possibly cv-qualified) object to the (possibly cv-qualified) same
1770 object type (or a reference to it), to a (possibly cv-qualified) base
1771 class of that type (or a reference to it).... */
1772 else if (CLASS_TYPE_P (from) && !related_p
1773 && !(flags & LOOKUP_NO_CONVERSION))
1774 {
1775 /* [dcl.init.ref]
1776
1777 If the initializer expression
1778
1779 -- has a class type (i.e., T2 is a class type) can be
1780 implicitly converted to an lvalue of type "cv3 T3," where
1781 "cv1 T1" is reference-compatible with "cv3 T3". (this
1782 conversion is selected by enumerating the applicable
1783 conversion functions (_over.match.ref_) and choosing the
1784 best one through overload resolution. (_over.match_).
1785
1786 the reference is bound to the lvalue result of the conversion
1787 in the second case. */
1788 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags,
1789 complain);
1790 if (cand)
1791 return cand->second_conv;
1792 }
1793
1794 /* From this point on, we conceptually need temporaries, even if we
1795 elide them. Only the cases above are "direct bindings". */
1796 if (flags & LOOKUP_NO_TEMP_BIND)
1797 return NULL;
1798
1799 /* [over.ics.rank]
1800
1801 When a parameter of reference type is not bound directly to an
1802 argument expression, the conversion sequence is the one required
1803 to convert the argument expression to the underlying type of the
1804 reference according to _over.best.ics_. Conceptually, this
1805 conversion sequence corresponds to copy-initializing a temporary
1806 of the underlying type with the argument expression. Any
1807 difference in top-level cv-qualification is subsumed by the
1808 initialization itself and does not constitute a conversion. */
1809
1810 /* [dcl.init.ref]
1811
1812 Otherwise, the reference shall be an lvalue reference to a
1813 non-volatile const type, or the reference shall be an rvalue
1814 reference.
1815
1816 We try below to treat this as a bad conversion to improve diagnostics,
1817 but if TO is an incomplete class, we need to reject this conversion
1818 now to avoid unnecessary instantiation. */
1819 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)
1820 && !COMPLETE_TYPE_P (to))
1821 return NULL;
1822
1823 /* We're generating a temporary now, but don't bind any more in the
1824 conversion (specifically, don't slice the temporary returned by a
1825 conversion operator). */
1826 flags |= LOOKUP_NO_TEMP_BIND;
1827
1828 /* Core issue 899: When [copy-]initializing a temporary to be bound
1829 to the first parameter of a copy constructor (12.8) called with
1830 a single argument in the context of direct-initialization,
1831 explicit conversion functions are also considered.
1832
1833 So don't set LOOKUP_ONLYCONVERTING in that case. */
1834 if (!(flags & LOOKUP_COPY_PARM))
1835 flags |= LOOKUP_ONLYCONVERTING;
1836
1837 if (!conv)
1838 conv = implicit_conversion (to, from, expr, c_cast_p,
1839 flags, complain);
1840 if (!conv)
1841 return NULL;
1842
1843 if (conv->user_conv_p)
1844 {
1845 if (copy_list_init)
1846 /* Remember this was copy-list-initialization. */
1847 conv->need_temporary_p = true;
1848
1849 /* If initializing the temporary used a conversion function,
1850 recalculate the second conversion sequence. */
1851 for (conversion *t = conv; t; t = next_conversion (t))
1852 if (t->kind == ck_user
1853 && DECL_CONV_FN_P (t->cand->fn))
1854 {
1855 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn));
1856 /* A prvalue of non-class type is cv-unqualified. */
1857 if (!TYPE_REF_P (ftype) && !CLASS_TYPE_P (ftype))
1858 ftype = cv_unqualified (ftype);
1859 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND;
1860 conversion *new_second
1861 = reference_binding (rto, ftype, NULL_TREE, c_cast_p,
1862 sflags, complain);
1863 if (!new_second)
1864 return NULL;
1865 return merge_conversion_sequences (t, new_second);
1866 }
1867 }
1868
1869 conv = build_conv (ck_ref_bind, rto, conv);
1870 /* This reference binding, unlike those above, requires the
1871 creation of a temporary. */
1872 conv->need_temporary_p = true;
1873 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1874
1875 /* [dcl.init.ref]
1876
1877 Otherwise, the reference shall be an lvalue reference to a
1878 non-volatile const type, or the reference shall be an rvalue
1879 reference. */
1880 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1881 conv->bad_p = true;
1882
1883 /* [dcl.init.ref]
1884
1885 Otherwise, a temporary of type "cv1 T1" is created and
1886 initialized from the initializer expression using the rules for a
1887 non-reference copy initialization. If T1 is reference-related to
1888 T2, cv1 must be the same cv-qualification as, or greater
1889 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1890 if (related_p && !at_least_as_qualified_p (to, from))
1891 conv->bad_p = true;
1892
1893 return conv;
1894 }
1895
1896 /* Returns the implicit conversion sequence (see [over.ics]) from type
1897 FROM to type TO. The optional expression EXPR may affect the
1898 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1899 true, this conversion is coming from a C-style cast. */
1900
1901 static conversion *
implicit_conversion(tree to,tree from,tree expr,bool c_cast_p,int flags,tsubst_flags_t complain)1902 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1903 int flags, tsubst_flags_t complain)
1904 {
1905 conversion *conv;
1906
1907 if (from == error_mark_node || to == error_mark_node
1908 || expr == error_mark_node)
1909 return NULL;
1910
1911 /* Other flags only apply to the primary function in overload
1912 resolution, or after we've chosen one. */
1913 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM
1914 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE
1915 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL);
1916
1917 /* FIXME: actually we don't want warnings either, but we can't just
1918 have 'complain &= ~(tf_warning|tf_error)' because it would cause
1919 the regression of, eg, g++.old-deja/g++.benjamin/16077.C.
1920 We really ought not to issue that warning until we've committed
1921 to that conversion. */
1922 complain &= ~tf_error;
1923
1924 /* Call reshape_init early to remove redundant braces. */
1925 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)
1926 && CLASS_TYPE_P (to)
1927 && COMPLETE_TYPE_P (complete_type (to))
1928 && !CLASSTYPE_NON_AGGREGATE (to))
1929 {
1930 expr = reshape_init (to, expr, complain);
1931 if (expr == error_mark_node)
1932 return NULL;
1933 from = TREE_TYPE (expr);
1934 }
1935
1936 if (TYPE_REF_P (to))
1937 conv = reference_binding (to, from, expr, c_cast_p, flags, complain);
1938 else
1939 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain);
1940
1941 if (conv)
1942 return conv;
1943
1944 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1945 {
1946 if (is_std_init_list (to) && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr))
1947 return build_list_conv (to, expr, flags, complain);
1948
1949 /* As an extension, allow list-initialization of _Complex. */
1950 if (TREE_CODE (to) == COMPLEX_TYPE
1951 && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr))
1952 {
1953 conv = build_complex_conv (to, expr, flags, complain);
1954 if (conv)
1955 return conv;
1956 }
1957
1958 /* Allow conversion from an initializer-list with one element to a
1959 scalar type. */
1960 if (SCALAR_TYPE_P (to))
1961 {
1962 int nelts = CONSTRUCTOR_NELTS (expr);
1963 tree elt;
1964
1965 if (nelts == 0)
1966 elt = build_value_init (to, tf_none);
1967 else if (nelts == 1 && !CONSTRUCTOR_IS_DESIGNATED_INIT (expr))
1968 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1969 else
1970 elt = error_mark_node;
1971
1972 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1973 c_cast_p, flags, complain);
1974 if (conv)
1975 {
1976 conv->check_narrowing = true;
1977 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1978 /* Too many levels of braces, i.e. '{{1}}'. */
1979 conv->bad_p = true;
1980 return conv;
1981 }
1982 }
1983 else if (TREE_CODE (to) == ARRAY_TYPE)
1984 return build_array_conv (to, expr, flags, complain);
1985 }
1986
1987 if (expr != NULL_TREE
1988 && (MAYBE_CLASS_TYPE_P (from)
1989 || MAYBE_CLASS_TYPE_P (to))
1990 && (flags & LOOKUP_NO_CONVERSION) == 0)
1991 {
1992 struct z_candidate *cand;
1993
1994 if (CLASS_TYPE_P (to)
1995 && BRACE_ENCLOSED_INITIALIZER_P (expr)
1996 && !CLASSTYPE_NON_AGGREGATE (complete_type (to)))
1997 return build_aggr_conv (to, expr, flags, complain);
1998
1999 cand = build_user_type_conversion_1 (to, expr, flags, complain);
2000 if (cand)
2001 {
2002 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
2003 && CONSTRUCTOR_NELTS (expr) == 1
2004 && !is_list_ctor (cand->fn))
2005 {
2006 /* "If C is not an initializer-list constructor and the
2007 initializer list has a single element of type cv U, where U is
2008 X or a class derived from X, the implicit conversion sequence
2009 has Exact Match rank if U is X, or Conversion rank if U is
2010 derived from X." */
2011 tree elt = CONSTRUCTOR_ELT (expr, 0)->value;
2012 tree elttype = TREE_TYPE (elt);
2013 if (reference_related_p (to, elttype))
2014 return implicit_conversion (to, elttype, elt,
2015 c_cast_p, flags, complain);
2016 }
2017 conv = cand->second_conv;
2018 }
2019
2020 /* We used to try to bind a reference to a temporary here, but that
2021 is now handled after the recursive call to this function at the end
2022 of reference_binding. */
2023 return conv;
2024 }
2025
2026 return NULL;
2027 }
2028
2029 /* Like implicit_conversion, but return NULL if the conversion is bad.
2030
2031 This is not static so that check_non_deducible_conversion can call it within
2032 add_template_candidate_real as part of overload resolution; it should not be
2033 called outside of overload resolution. */
2034
2035 conversion *
good_conversion(tree to,tree from,tree expr,int flags,tsubst_flags_t complain)2036 good_conversion (tree to, tree from, tree expr,
2037 int flags, tsubst_flags_t complain)
2038 {
2039 conversion *c = implicit_conversion (to, from, expr, /*cast*/false,
2040 flags, complain);
2041 if (c && c->bad_p)
2042 c = NULL;
2043 return c;
2044 }
2045
2046 /* Add a new entry to the list of candidates. Used by the add_*_candidate
2047 functions. ARGS will not be changed until a single candidate is
2048 selected. */
2049
2050 static struct z_candidate *
add_candidate(struct z_candidate ** candidates,tree fn,tree first_arg,const vec<tree,va_gc> * args,size_t num_convs,conversion ** convs,tree access_path,tree conversion_path,int viable,struct rejection_reason * reason,int flags)2051 add_candidate (struct z_candidate **candidates,
2052 tree fn, tree first_arg, const vec<tree, va_gc> *args,
2053 size_t num_convs, conversion **convs,
2054 tree access_path, tree conversion_path,
2055 int viable, struct rejection_reason *reason,
2056 int flags)
2057 {
2058 struct z_candidate *cand = (struct z_candidate *)
2059 conversion_obstack_alloc (sizeof (struct z_candidate));
2060
2061 cand->fn = fn;
2062 cand->first_arg = first_arg;
2063 cand->args = args;
2064 cand->convs = convs;
2065 cand->num_convs = num_convs;
2066 cand->access_path = access_path;
2067 cand->conversion_path = conversion_path;
2068 cand->viable = viable;
2069 cand->reason = reason;
2070 cand->next = *candidates;
2071 cand->flags = flags;
2072 *candidates = cand;
2073
2074 return cand;
2075 }
2076
2077 /* Return the number of remaining arguments in the parameter list
2078 beginning with ARG. */
2079
2080 int
remaining_arguments(tree arg)2081 remaining_arguments (tree arg)
2082 {
2083 int n;
2084
2085 for (n = 0; arg != NULL_TREE && arg != void_list_node;
2086 arg = TREE_CHAIN (arg))
2087 n++;
2088
2089 return n;
2090 }
2091
2092 /* [over.match.copy]: When initializing a temporary object (12.2) to be bound
2093 to the first parameter of a constructor where the parameter is of type
2094 "reference to possibly cv-qualified T" and the constructor is called with a
2095 single argument in the context of direct-initialization of an object of type
2096 "cv2 T", explicit conversion functions are also considered.
2097
2098 So set LOOKUP_COPY_PARM to let reference_binding know that
2099 it's being called in that context. */
2100
2101 int
conv_flags(int i,int nargs,tree fn,tree arg,int flags)2102 conv_flags (int i, int nargs, tree fn, tree arg, int flags)
2103 {
2104 int lflags = flags;
2105 tree t;
2106 if (i == 0 && nargs == 1 && DECL_CONSTRUCTOR_P (fn)
2107 && (t = FUNCTION_FIRST_USER_PARMTYPE (fn))
2108 && (same_type_ignoring_top_level_qualifiers_p
2109 (non_reference (TREE_VALUE (t)), DECL_CONTEXT (fn))))
2110 {
2111 if (!(flags & LOOKUP_ONLYCONVERTING))
2112 lflags |= LOOKUP_COPY_PARM;
2113 if ((flags & LOOKUP_LIST_INIT_CTOR)
2114 && BRACE_ENCLOSED_INITIALIZER_P (arg))
2115 lflags |= LOOKUP_NO_CONVERSION;
2116 }
2117 else
2118 lflags |= LOOKUP_ONLYCONVERTING;
2119
2120 return lflags;
2121 }
2122
2123 /* Create an overload candidate for the function or method FN called
2124 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
2125 FLAGS is passed on to implicit_conversion.
2126
2127 This does not change ARGS.
2128
2129 CTYPE, if non-NULL, is the type we want to pretend this function
2130 comes from for purposes of overload resolution. */
2131
2132 static struct z_candidate *
add_function_candidate(struct z_candidate ** candidates,tree fn,tree ctype,tree first_arg,const vec<tree,va_gc> * args,tree access_path,tree conversion_path,int flags,conversion ** convs,tsubst_flags_t complain)2133 add_function_candidate (struct z_candidate **candidates,
2134 tree fn, tree ctype, tree first_arg,
2135 const vec<tree, va_gc> *args, tree access_path,
2136 tree conversion_path, int flags,
2137 conversion **convs,
2138 tsubst_flags_t complain)
2139 {
2140 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
2141 int i, len;
2142 tree parmnode;
2143 tree orig_first_arg = first_arg;
2144 int skip;
2145 int viable = 1;
2146 struct rejection_reason *reason = NULL;
2147
2148 /* At this point we should not see any functions which haven't been
2149 explicitly declared, except for friend functions which will have
2150 been found using argument dependent lookup. */
2151 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
2152
2153 /* The `this', `in_chrg' and VTT arguments to constructors are not
2154 considered in overload resolution. */
2155 if (DECL_CONSTRUCTOR_P (fn))
2156 {
2157 if (ctor_omit_inherited_parms (fn))
2158 /* Bring back parameters omitted from an inherited ctor. */
2159 parmlist = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn));
2160 else
2161 parmlist = skip_artificial_parms_for (fn, parmlist);
2162 skip = num_artificial_parms_for (fn);
2163 if (skip > 0 && first_arg != NULL_TREE)
2164 {
2165 --skip;
2166 first_arg = NULL_TREE;
2167 }
2168 }
2169 else
2170 skip = 0;
2171
2172 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0);
2173 if (!convs)
2174 convs = alloc_conversions (len);
2175
2176 /* 13.3.2 - Viable functions [over.match.viable]
2177 First, to be a viable function, a candidate function shall have enough
2178 parameters to agree in number with the arguments in the list.
2179
2180 We need to check this first; otherwise, checking the ICSes might cause
2181 us to produce an ill-formed template instantiation. */
2182
2183 parmnode = parmlist;
2184 for (i = 0; i < len; ++i)
2185 {
2186 if (parmnode == NULL_TREE || parmnode == void_list_node)
2187 break;
2188 parmnode = TREE_CHAIN (parmnode);
2189 }
2190
2191 if ((i < len && parmnode)
2192 || !sufficient_parms_p (parmnode))
2193 {
2194 int remaining = remaining_arguments (parmnode);
2195 viable = 0;
2196 reason = arity_rejection (first_arg, i + remaining, len);
2197 }
2198
2199 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first
2200 parameter of type "reference to cv C" (including such a constructor
2201 instantiated from a template) is excluded from the set of candidate
2202 functions when used to construct an object of type D with an argument list
2203 containing a single argument if C is reference-related to D. */
2204 if (viable && len == 1 && parmlist && DECL_CONSTRUCTOR_P (fn)
2205 && flag_new_inheriting_ctors
2206 && DECL_INHERITED_CTOR (fn))
2207 {
2208 tree ptype = non_reference (TREE_VALUE (parmlist));
2209 tree dtype = DECL_CONTEXT (fn);
2210 tree btype = DECL_INHERITED_CTOR_BASE (fn);
2211 if (reference_related_p (ptype, dtype)
2212 && reference_related_p (btype, ptype))
2213 {
2214 viable = false;
2215 reason = inherited_ctor_rejection ();
2216 }
2217 }
2218
2219 /* Second, for a function to be viable, its constraints must be
2220 satisfied. */
2221 if (flag_concepts && viable
2222 && !constraints_satisfied_p (fn))
2223 {
2224 reason = constraint_failure (fn);
2225 viable = false;
2226 }
2227
2228 /* When looking for a function from a subobject from an implicit
2229 copy/move constructor/operator=, don't consider anything that takes (a
2230 reference to) an unrelated type. See c++/44909 and core 1092. */
2231 if (viable && parmlist && (flags & LOOKUP_DEFAULTED))
2232 {
2233 if (DECL_CONSTRUCTOR_P (fn))
2234 i = 1;
2235 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
2236 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR))
2237 i = 2;
2238 else
2239 i = 0;
2240 if (i && len == i)
2241 {
2242 parmnode = chain_index (i-1, parmlist);
2243 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
2244 ctype))
2245 viable = 0;
2246 }
2247
2248 /* This only applies at the top level. */
2249 flags &= ~LOOKUP_DEFAULTED;
2250 }
2251
2252 if (! viable)
2253 goto out;
2254
2255 /* Third, for F to be a viable function, there shall exist for each
2256 argument an implicit conversion sequence that converts that argument
2257 to the corresponding parameter of F. */
2258
2259 parmnode = parmlist;
2260
2261 for (i = 0; i < len; ++i)
2262 {
2263 tree argtype, to_type;
2264 tree arg;
2265 conversion *t;
2266 int is_this;
2267
2268 if (parmnode == void_list_node)
2269 break;
2270
2271 if (convs[i])
2272 {
2273 /* Already set during deduction. */
2274 parmnode = TREE_CHAIN (parmnode);
2275 continue;
2276 }
2277
2278 if (i == 0 && first_arg != NULL_TREE)
2279 arg = first_arg;
2280 else
2281 arg = CONST_CAST_TREE (
2282 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]);
2283 argtype = lvalue_type (arg);
2284
2285 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
2286 && ! DECL_CONSTRUCTOR_P (fn));
2287
2288 if (parmnode)
2289 {
2290 tree parmtype = TREE_VALUE (parmnode);
2291
2292 parmnode = TREE_CHAIN (parmnode);
2293
2294 /* The type of the implicit object parameter ('this') for
2295 overload resolution is not always the same as for the
2296 function itself; conversion functions are considered to
2297 be members of the class being converted, and functions
2298 introduced by a using-declaration are considered to be
2299 members of the class that uses them.
2300
2301 Since build_over_call ignores the ICS for the `this'
2302 parameter, we can just change the parm type. */
2303 if (ctype && is_this)
2304 {
2305 parmtype = cp_build_qualified_type
2306 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
2307 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn)))
2308 {
2309 /* If the function has a ref-qualifier, the implicit
2310 object parameter has reference type. */
2311 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
2312 parmtype = cp_build_reference_type (parmtype, rv);
2313 /* The special handling of 'this' conversions in compare_ics
2314 does not apply if there is a ref-qualifier. */
2315 is_this = false;
2316 }
2317 else
2318 {
2319 parmtype = build_pointer_type (parmtype);
2320 /* We don't use build_this here because we don't want to
2321 capture the object argument until we've chosen a
2322 non-static member function. */
2323 arg = build_address (arg);
2324 argtype = lvalue_type (arg);
2325 }
2326 }
2327
2328 int lflags = conv_flags (i, len-skip, fn, arg, flags);
2329
2330 t = implicit_conversion (parmtype, argtype, arg,
2331 /*c_cast_p=*/false, lflags, complain);
2332 to_type = parmtype;
2333 }
2334 else
2335 {
2336 t = build_identity_conv (argtype, arg);
2337 t->ellipsis_p = true;
2338 to_type = argtype;
2339 }
2340
2341 if (t && is_this)
2342 t->this_p = true;
2343
2344 convs[i] = t;
2345 if (! t)
2346 {
2347 viable = 0;
2348 reason = arg_conversion_rejection (first_arg, i, argtype, to_type,
2349 EXPR_LOCATION (arg));
2350 break;
2351 }
2352
2353 if (t->bad_p)
2354 {
2355 viable = -1;
2356 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type,
2357 EXPR_LOCATION (arg));
2358
2359 }
2360 }
2361
2362 out:
2363 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
2364 access_path, conversion_path, viable, reason, flags);
2365 }
2366
2367 /* Create an overload candidate for the conversion function FN which will
2368 be invoked for expression OBJ, producing a pointer-to-function which
2369 will in turn be called with the argument list FIRST_ARG/ARGLIST,
2370 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
2371 passed on to implicit_conversion.
2372
2373 Actually, we don't really care about FN; we care about the type it
2374 converts to. There may be multiple conversion functions that will
2375 convert to that type, and we rely on build_user_type_conversion_1 to
2376 choose the best one; so when we create our candidate, we record the type
2377 instead of the function. */
2378
2379 static struct z_candidate *
add_conv_candidate(struct z_candidate ** candidates,tree fn,tree obj,const vec<tree,va_gc> * arglist,tree access_path,tree conversion_path,tsubst_flags_t complain)2380 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
2381 const vec<tree, va_gc> *arglist,
2382 tree access_path, tree conversion_path,
2383 tsubst_flags_t complain)
2384 {
2385 tree totype = TREE_TYPE (TREE_TYPE (fn));
2386 int i, len, viable, flags;
2387 tree parmlist, parmnode;
2388 conversion **convs;
2389 struct rejection_reason *reason;
2390
2391 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
2392 parmlist = TREE_TYPE (parmlist);
2393 parmlist = TYPE_ARG_TYPES (parmlist);
2394
2395 len = vec_safe_length (arglist) + 1;
2396 convs = alloc_conversions (len);
2397 parmnode = parmlist;
2398 viable = 1;
2399 flags = LOOKUP_IMPLICIT;
2400 reason = NULL;
2401
2402 /* Don't bother looking up the same type twice. */
2403 if (*candidates && (*candidates)->fn == totype)
2404 return NULL;
2405
2406 for (i = 0; i < len; ++i)
2407 {
2408 tree arg, argtype, convert_type = NULL_TREE;
2409 conversion *t;
2410
2411 if (i == 0)
2412 arg = obj;
2413 else
2414 arg = (*arglist)[i - 1];
2415 argtype = lvalue_type (arg);
2416
2417 if (i == 0)
2418 {
2419 t = build_identity_conv (argtype, NULL_TREE);
2420 t = build_conv (ck_user, totype, t);
2421 /* Leave the 'cand' field null; we'll figure out the conversion in
2422 convert_like_real if this candidate is chosen. */
2423 convert_type = totype;
2424 }
2425 else if (parmnode == void_list_node)
2426 break;
2427 else if (parmnode)
2428 {
2429 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2430 /*c_cast_p=*/false, flags, complain);
2431 convert_type = TREE_VALUE (parmnode);
2432 }
2433 else
2434 {
2435 t = build_identity_conv (argtype, arg);
2436 t->ellipsis_p = true;
2437 convert_type = argtype;
2438 }
2439
2440 convs[i] = t;
2441 if (! t)
2442 break;
2443
2444 if (t->bad_p)
2445 {
2446 viable = -1;
2447 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type,
2448 EXPR_LOCATION (arg));
2449 }
2450
2451 if (i == 0)
2452 continue;
2453
2454 if (parmnode)
2455 parmnode = TREE_CHAIN (parmnode);
2456 }
2457
2458 if (i < len
2459 || ! sufficient_parms_p (parmnode))
2460 {
2461 int remaining = remaining_arguments (parmnode);
2462 viable = 0;
2463 reason = arity_rejection (NULL_TREE, i + remaining, len);
2464 }
2465
2466 return add_candidate (candidates, totype, obj, arglist, len, convs,
2467 access_path, conversion_path, viable, reason, flags);
2468 }
2469
2470 static void
build_builtin_candidate(struct z_candidate ** candidates,tree fnname,tree type1,tree type2,tree * args,tree * argtypes,int flags,tsubst_flags_t complain)2471 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2472 tree type1, tree type2, tree *args, tree *argtypes,
2473 int flags, tsubst_flags_t complain)
2474 {
2475 conversion *t;
2476 conversion **convs;
2477 size_t num_convs;
2478 int viable = 1, i;
2479 tree types[2];
2480 struct rejection_reason *reason = NULL;
2481
2482 types[0] = type1;
2483 types[1] = type2;
2484
2485 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2486 convs = alloc_conversions (num_convs);
2487
2488 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2489 conversion ops are allowed. We handle that here by just checking for
2490 boolean_type_node because other operators don't ask for it. COND_EXPR
2491 also does contextual conversion to bool for the first operand, but we
2492 handle that in build_conditional_expr, and type1 here is operand 2. */
2493 if (type1 != boolean_type_node)
2494 flags |= LOOKUP_ONLYCONVERTING;
2495
2496 for (i = 0; i < 2; ++i)
2497 {
2498 if (! args[i])
2499 break;
2500
2501 t = implicit_conversion (types[i], argtypes[i], args[i],
2502 /*c_cast_p=*/false, flags, complain);
2503 if (! t)
2504 {
2505 viable = 0;
2506 /* We need something for printing the candidate. */
2507 t = build_identity_conv (types[i], NULL_TREE);
2508 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i],
2509 types[i], EXPR_LOCATION (args[i]));
2510 }
2511 else if (t->bad_p)
2512 {
2513 viable = 0;
2514 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i],
2515 types[i],
2516 EXPR_LOCATION (args[i]));
2517 }
2518 convs[i] = t;
2519 }
2520
2521 /* For COND_EXPR we rearranged the arguments; undo that now. */
2522 if (args[2])
2523 {
2524 convs[2] = convs[1];
2525 convs[1] = convs[0];
2526 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2527 /*c_cast_p=*/false, flags,
2528 complain);
2529 if (t)
2530 convs[0] = t;
2531 else
2532 {
2533 viable = 0;
2534 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2535 boolean_type_node,
2536 EXPR_LOCATION (args[2]));
2537 }
2538 }
2539
2540 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2541 num_convs, convs,
2542 /*access_path=*/NULL_TREE,
2543 /*conversion_path=*/NULL_TREE,
2544 viable, reason, flags);
2545 }
2546
2547 static bool
is_complete(tree t)2548 is_complete (tree t)
2549 {
2550 return COMPLETE_TYPE_P (complete_type (t));
2551 }
2552
2553 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2554
2555 static bool
promoted_arithmetic_type_p(tree type)2556 promoted_arithmetic_type_p (tree type)
2557 {
2558 /* [over.built]
2559
2560 In this section, the term promoted integral type is used to refer
2561 to those integral types which are preserved by integral promotion
2562 (including e.g. int and long but excluding e.g. char).
2563 Similarly, the term promoted arithmetic type refers to promoted
2564 integral types plus floating types. */
2565 return ((CP_INTEGRAL_TYPE_P (type)
2566 && same_type_p (type_promotes_to (type), type))
2567 || TREE_CODE (type) == REAL_TYPE);
2568 }
2569
2570 /* Create any builtin operator overload candidates for the operator in
2571 question given the converted operand types TYPE1 and TYPE2. The other
2572 args are passed through from add_builtin_candidates to
2573 build_builtin_candidate.
2574
2575 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2576 If CODE is requires candidates operands of the same type of the kind
2577 of which TYPE1 and TYPE2 are, we add both candidates
2578 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2579
2580 static void
add_builtin_candidate(struct z_candidate ** candidates,enum tree_code code,enum tree_code code2,tree fnname,tree type1,tree type2,tree * args,tree * argtypes,int flags,tsubst_flags_t complain)2581 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2582 enum tree_code code2, tree fnname, tree type1,
2583 tree type2, tree *args, tree *argtypes, int flags,
2584 tsubst_flags_t complain)
2585 {
2586 switch (code)
2587 {
2588 case POSTINCREMENT_EXPR:
2589 case POSTDECREMENT_EXPR:
2590 args[1] = integer_zero_node;
2591 type2 = integer_type_node;
2592 break;
2593 default:
2594 break;
2595 }
2596
2597 switch (code)
2598 {
2599
2600 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2601 and VQ is either volatile or empty, there exist candidate operator
2602 functions of the form
2603 VQ T& operator++(VQ T&);
2604 T operator++(VQ T&, int);
2605 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2606 type other than bool, and VQ is either volatile or empty, there exist
2607 candidate operator functions of the form
2608 VQ T& operator--(VQ T&);
2609 T operator--(VQ T&, int);
2610 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2611 complete object type, and VQ is either volatile or empty, there exist
2612 candidate operator functions of the form
2613 T*VQ& operator++(T*VQ&);
2614 T*VQ& operator--(T*VQ&);
2615 T* operator++(T*VQ&, int);
2616 T* operator--(T*VQ&, int); */
2617
2618 case POSTDECREMENT_EXPR:
2619 case PREDECREMENT_EXPR:
2620 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2621 return;
2622 /* FALLTHRU */
2623 case POSTINCREMENT_EXPR:
2624 case PREINCREMENT_EXPR:
2625 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2626 {
2627 type1 = build_reference_type (type1);
2628 break;
2629 }
2630 return;
2631
2632 /* 7 For every cv-qualified or cv-unqualified object type T, there
2633 exist candidate operator functions of the form
2634
2635 T& operator*(T*);
2636
2637 8 For every function type T, there exist candidate operator functions of
2638 the form
2639 T& operator*(T*); */
2640
2641 case INDIRECT_REF:
2642 if (TYPE_PTR_P (type1)
2643 && (TYPE_PTROB_P (type1)
2644 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2645 break;
2646 return;
2647
2648 /* 9 For every type T, there exist candidate operator functions of the form
2649 T* operator+(T*);
2650
2651 10For every promoted arithmetic type T, there exist candidate operator
2652 functions of the form
2653 T operator+(T);
2654 T operator-(T); */
2655
2656 case UNARY_PLUS_EXPR: /* unary + */
2657 if (TYPE_PTR_P (type1))
2658 break;
2659 /* FALLTHRU */
2660 case NEGATE_EXPR:
2661 if (ARITHMETIC_TYPE_P (type1))
2662 break;
2663 return;
2664
2665 /* 11For every promoted integral type T, there exist candidate operator
2666 functions of the form
2667 T operator~(T); */
2668
2669 case BIT_NOT_EXPR:
2670 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2671 break;
2672 return;
2673
2674 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2675 is the same type as C2 or is a derived class of C2, T is a complete
2676 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2677 there exist candidate operator functions of the form
2678 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2679 where CV12 is the union of CV1 and CV2. */
2680
2681 case MEMBER_REF:
2682 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2))
2683 {
2684 tree c1 = TREE_TYPE (type1);
2685 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2686
2687 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2688 && (TYPE_PTRMEMFUNC_P (type2)
2689 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2690 break;
2691 }
2692 return;
2693
2694 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2695 didate operator functions of the form
2696 LR operator*(L, R);
2697 LR operator/(L, R);
2698 LR operator+(L, R);
2699 LR operator-(L, R);
2700 bool operator<(L, R);
2701 bool operator>(L, R);
2702 bool operator<=(L, R);
2703 bool operator>=(L, R);
2704 bool operator==(L, R);
2705 bool operator!=(L, R);
2706 where LR is the result of the usual arithmetic conversions between
2707 types L and R.
2708
2709 14For every pair of types T and I, where T is a cv-qualified or cv-
2710 unqualified complete object type and I is a promoted integral type,
2711 there exist candidate operator functions of the form
2712 T* operator+(T*, I);
2713 T& operator[](T*, I);
2714 T* operator-(T*, I);
2715 T* operator+(I, T*);
2716 T& operator[](I, T*);
2717
2718 15For every T, where T is a pointer to complete object type, there exist
2719 candidate operator functions of the form112)
2720 ptrdiff_t operator-(T, T);
2721
2722 16For every pointer or enumeration type T, there exist candidate operator
2723 functions of the form
2724 bool operator<(T, T);
2725 bool operator>(T, T);
2726 bool operator<=(T, T);
2727 bool operator>=(T, T);
2728 bool operator==(T, T);
2729 bool operator!=(T, T);
2730
2731 17For every pointer to member type T, there exist candidate operator
2732 functions of the form
2733 bool operator==(T, T);
2734 bool operator!=(T, T); */
2735
2736 case MINUS_EXPR:
2737 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2738 break;
2739 if (TYPE_PTROB_P (type1)
2740 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2741 {
2742 type2 = ptrdiff_type_node;
2743 break;
2744 }
2745 /* FALLTHRU */
2746 case MULT_EXPR:
2747 case TRUNC_DIV_EXPR:
2748 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2749 break;
2750 return;
2751
2752 case EQ_EXPR:
2753 case NE_EXPR:
2754 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2755 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)))
2756 break;
2757 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1]))
2758 {
2759 type2 = type1;
2760 break;
2761 }
2762 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0]))
2763 {
2764 type1 = type2;
2765 break;
2766 }
2767 /* Fall through. */
2768 case LT_EXPR:
2769 case GT_EXPR:
2770 case LE_EXPR:
2771 case GE_EXPR:
2772 case MAX_EXPR:
2773 case MIN_EXPR:
2774 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2775 break;
2776 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2777 break;
2778 if (TREE_CODE (type1) == ENUMERAL_TYPE
2779 && TREE_CODE (type2) == ENUMERAL_TYPE)
2780 break;
2781 if (TYPE_PTR_P (type1)
2782 && null_ptr_cst_p (args[1]))
2783 {
2784 type2 = type1;
2785 break;
2786 }
2787 if (null_ptr_cst_p (args[0])
2788 && TYPE_PTR_P (type2))
2789 {
2790 type1 = type2;
2791 break;
2792 }
2793 return;
2794
2795 case PLUS_EXPR:
2796 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2797 break;
2798 /* FALLTHRU */
2799 case ARRAY_REF:
2800 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2801 {
2802 type1 = ptrdiff_type_node;
2803 break;
2804 }
2805 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2806 {
2807 type2 = ptrdiff_type_node;
2808 break;
2809 }
2810 return;
2811
2812 /* 18For every pair of promoted integral types L and R, there exist candi-
2813 date operator functions of the form
2814 LR operator%(L, R);
2815 LR operator&(L, R);
2816 LR operator^(L, R);
2817 LR operator|(L, R);
2818 L operator<<(L, R);
2819 L operator>>(L, R);
2820 where LR is the result of the usual arithmetic conversions between
2821 types L and R. */
2822
2823 case TRUNC_MOD_EXPR:
2824 case BIT_AND_EXPR:
2825 case BIT_IOR_EXPR:
2826 case BIT_XOR_EXPR:
2827 case LSHIFT_EXPR:
2828 case RSHIFT_EXPR:
2829 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2830 break;
2831 return;
2832
2833 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2834 type, VQ is either volatile or empty, and R is a promoted arithmetic
2835 type, there exist candidate operator functions of the form
2836 VQ L& operator=(VQ L&, R);
2837 VQ L& operator*=(VQ L&, R);
2838 VQ L& operator/=(VQ L&, R);
2839 VQ L& operator+=(VQ L&, R);
2840 VQ L& operator-=(VQ L&, R);
2841
2842 20For every pair T, VQ), where T is any type and VQ is either volatile
2843 or empty, there exist candidate operator functions of the form
2844 T*VQ& operator=(T*VQ&, T*);
2845
2846 21For every pair T, VQ), where T is a pointer to member type and VQ is
2847 either volatile or empty, there exist candidate operator functions of
2848 the form
2849 VQ T& operator=(VQ T&, T);
2850
2851 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2852 unqualified complete object type, VQ is either volatile or empty, and
2853 I is a promoted integral type, there exist candidate operator func-
2854 tions of the form
2855 T*VQ& operator+=(T*VQ&, I);
2856 T*VQ& operator-=(T*VQ&, I);
2857
2858 23For every triple L, VQ, R), where L is an integral or enumeration
2859 type, VQ is either volatile or empty, and R is a promoted integral
2860 type, there exist candidate operator functions of the form
2861
2862 VQ L& operator%=(VQ L&, R);
2863 VQ L& operator<<=(VQ L&, R);
2864 VQ L& operator>>=(VQ L&, R);
2865 VQ L& operator&=(VQ L&, R);
2866 VQ L& operator^=(VQ L&, R);
2867 VQ L& operator|=(VQ L&, R); */
2868
2869 case MODIFY_EXPR:
2870 switch (code2)
2871 {
2872 case PLUS_EXPR:
2873 case MINUS_EXPR:
2874 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2875 {
2876 type2 = ptrdiff_type_node;
2877 break;
2878 }
2879 /* FALLTHRU */
2880 case MULT_EXPR:
2881 case TRUNC_DIV_EXPR:
2882 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2883 break;
2884 return;
2885
2886 case TRUNC_MOD_EXPR:
2887 case BIT_AND_EXPR:
2888 case BIT_IOR_EXPR:
2889 case BIT_XOR_EXPR:
2890 case LSHIFT_EXPR:
2891 case RSHIFT_EXPR:
2892 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2893 break;
2894 return;
2895
2896 case NOP_EXPR:
2897 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2898 break;
2899 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2900 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2901 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2902 || ((TYPE_PTRMEMFUNC_P (type1)
2903 || TYPE_PTR_P (type1))
2904 && null_ptr_cst_p (args[1])))
2905 {
2906 type2 = type1;
2907 break;
2908 }
2909 return;
2910
2911 default:
2912 gcc_unreachable ();
2913 }
2914 type1 = build_reference_type (type1);
2915 break;
2916
2917 case COND_EXPR:
2918 /* [over.built]
2919
2920 For every pair of promoted arithmetic types L and R, there
2921 exist candidate operator functions of the form
2922
2923 LR operator?(bool, L, R);
2924
2925 where LR is the result of the usual arithmetic conversions
2926 between types L and R.
2927
2928 For every type T, where T is a pointer or pointer-to-member
2929 type, there exist candidate operator functions of the form T
2930 operator?(bool, T, T); */
2931
2932 if (promoted_arithmetic_type_p (type1)
2933 && promoted_arithmetic_type_p (type2))
2934 /* That's OK. */
2935 break;
2936
2937 /* Otherwise, the types should be pointers. */
2938 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2))
2939 return;
2940
2941 /* We don't check that the two types are the same; the logic
2942 below will actually create two candidates; one in which both
2943 parameter types are TYPE1, and one in which both parameter
2944 types are TYPE2. */
2945 break;
2946
2947 case REALPART_EXPR:
2948 case IMAGPART_EXPR:
2949 if (ARITHMETIC_TYPE_P (type1))
2950 break;
2951 return;
2952
2953 default:
2954 gcc_unreachable ();
2955 }
2956
2957 /* Make sure we don't create builtin candidates with dependent types. */
2958 bool u1 = uses_template_parms (type1);
2959 bool u2 = type2 ? uses_template_parms (type2) : false;
2960 if (u1 || u2)
2961 {
2962 /* Try to recover if one of the types is non-dependent. But if
2963 there's only one type, there's nothing we can do. */
2964 if (!type2)
2965 return;
2966 /* And we lose if both are dependent. */
2967 if (u1 && u2)
2968 return;
2969 /* Or if they have different forms. */
2970 if (TREE_CODE (type1) != TREE_CODE (type2))
2971 return;
2972
2973 if (u1 && !u2)
2974 type1 = type2;
2975 else if (u2 && !u1)
2976 type2 = type1;
2977 }
2978
2979 /* If we're dealing with two pointer types or two enumeral types,
2980 we need candidates for both of them. */
2981 if (type2 && !same_type_p (type1, type2)
2982 && TREE_CODE (type1) == TREE_CODE (type2)
2983 && (TYPE_REF_P (type1)
2984 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2985 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2986 || TYPE_PTRMEMFUNC_P (type1)
2987 || MAYBE_CLASS_TYPE_P (type1)
2988 || TREE_CODE (type1) == ENUMERAL_TYPE))
2989 {
2990 if (TYPE_PTR_OR_PTRMEM_P (type1))
2991 {
2992 tree cptype = composite_pointer_type (type1, type2,
2993 error_mark_node,
2994 error_mark_node,
2995 CPO_CONVERSION,
2996 tf_none);
2997 if (cptype != error_mark_node)
2998 {
2999 build_builtin_candidate
3000 (candidates, fnname, cptype, cptype, args, argtypes,
3001 flags, complain);
3002 return;
3003 }
3004 }
3005
3006 build_builtin_candidate
3007 (candidates, fnname, type1, type1, args, argtypes, flags, complain);
3008 build_builtin_candidate
3009 (candidates, fnname, type2, type2, args, argtypes, flags, complain);
3010 return;
3011 }
3012
3013 build_builtin_candidate
3014 (candidates, fnname, type1, type2, args, argtypes, flags, complain);
3015 }
3016
3017 tree
type_decays_to(tree type)3018 type_decays_to (tree type)
3019 {
3020 if (TREE_CODE (type) == ARRAY_TYPE)
3021 return build_pointer_type (TREE_TYPE (type));
3022 if (TREE_CODE (type) == FUNCTION_TYPE)
3023 return build_pointer_type (type);
3024 return type;
3025 }
3026
3027 /* There are three conditions of builtin candidates:
3028
3029 1) bool-taking candidates. These are the same regardless of the input.
3030 2) pointer-pair taking candidates. These are generated for each type
3031 one of the input types converts to.
3032 3) arithmetic candidates. According to the standard, we should generate
3033 all of these, but I'm trying not to...
3034
3035 Here we generate a superset of the possible candidates for this particular
3036 case. That is a subset of the full set the standard defines, plus some
3037 other cases which the standard disallows. add_builtin_candidate will
3038 filter out the invalid set. */
3039
3040 static void
add_builtin_candidates(struct z_candidate ** candidates,enum tree_code code,enum tree_code code2,tree fnname,tree * args,int flags,tsubst_flags_t complain)3041 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
3042 enum tree_code code2, tree fnname, tree *args,
3043 int flags, tsubst_flags_t complain)
3044 {
3045 int ref1, i;
3046 int enum_p = 0;
3047 tree type, argtypes[3], t;
3048 /* TYPES[i] is the set of possible builtin-operator parameter types
3049 we will consider for the Ith argument. */
3050 vec<tree, va_gc> *types[2];
3051 unsigned ix;
3052
3053 for (i = 0; i < 3; ++i)
3054 {
3055 if (args[i])
3056 argtypes[i] = unlowered_expr_type (args[i]);
3057 else
3058 argtypes[i] = NULL_TREE;
3059 }
3060
3061 switch (code)
3062 {
3063 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
3064 and VQ is either volatile or empty, there exist candidate operator
3065 functions of the form
3066 VQ T& operator++(VQ T&); */
3067
3068 case POSTINCREMENT_EXPR:
3069 case PREINCREMENT_EXPR:
3070 case POSTDECREMENT_EXPR:
3071 case PREDECREMENT_EXPR:
3072 case MODIFY_EXPR:
3073 ref1 = 1;
3074 break;
3075
3076 /* 24There also exist candidate operator functions of the form
3077 bool operator!(bool);
3078 bool operator&&(bool, bool);
3079 bool operator||(bool, bool); */
3080
3081 case TRUTH_NOT_EXPR:
3082 build_builtin_candidate
3083 (candidates, fnname, boolean_type_node,
3084 NULL_TREE, args, argtypes, flags, complain);
3085 return;
3086
3087 case TRUTH_ORIF_EXPR:
3088 case TRUTH_ANDIF_EXPR:
3089 build_builtin_candidate
3090 (candidates, fnname, boolean_type_node,
3091 boolean_type_node, args, argtypes, flags, complain);
3092 return;
3093
3094 case ADDR_EXPR:
3095 case COMPOUND_EXPR:
3096 case COMPONENT_REF:
3097 return;
3098
3099 case COND_EXPR:
3100 case EQ_EXPR:
3101 case NE_EXPR:
3102 case LT_EXPR:
3103 case LE_EXPR:
3104 case GT_EXPR:
3105 case GE_EXPR:
3106 enum_p = 1;
3107 /* Fall through. */
3108
3109 default:
3110 ref1 = 0;
3111 }
3112
3113 types[0] = make_tree_vector ();
3114 types[1] = make_tree_vector ();
3115
3116 for (i = 0; i < 2; ++i)
3117 {
3118 if (! args[i])
3119 ;
3120 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
3121 {
3122 tree convs;
3123
3124 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
3125 return;
3126
3127 convs = lookup_conversions (argtypes[i]);
3128
3129 if (code == COND_EXPR)
3130 {
3131 if (lvalue_p (args[i]))
3132 vec_safe_push (types[i], build_reference_type (argtypes[i]));
3133
3134 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i]));
3135 }
3136
3137 else if (! convs)
3138 return;
3139
3140 for (; convs; convs = TREE_CHAIN (convs))
3141 {
3142 type = TREE_TYPE (convs);
3143
3144 if (i == 0 && ref1
3145 && (!TYPE_REF_P (type)
3146 || CP_TYPE_CONST_P (TREE_TYPE (type))))
3147 continue;
3148
3149 if (code == COND_EXPR && TYPE_REF_P (type))
3150 vec_safe_push (types[i], type);
3151
3152 type = non_reference (type);
3153 if (i != 0 || ! ref1)
3154 {
3155 type = cv_unqualified (type_decays_to (type));
3156 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
3157 vec_safe_push (types[i], type);
3158 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
3159 type = type_promotes_to (type);
3160 }
3161
3162 if (! vec_member (type, types[i]))
3163 vec_safe_push (types[i], type);
3164 }
3165 }
3166 else
3167 {
3168 if (code == COND_EXPR && lvalue_p (args[i]))
3169 vec_safe_push (types[i], build_reference_type (argtypes[i]));
3170 type = non_reference (argtypes[i]);
3171 if (i != 0 || ! ref1)
3172 {
3173 type = cv_unqualified (type_decays_to (type));
3174 if (enum_p && UNSCOPED_ENUM_P (type))
3175 vec_safe_push (types[i], type);
3176 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
3177 type = type_promotes_to (type);
3178 }
3179 vec_safe_push (types[i], type);
3180 }
3181 }
3182
3183 /* Run through the possible parameter types of both arguments,
3184 creating candidates with those parameter types. */
3185 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t)
3186 {
3187 unsigned jx;
3188 tree u;
3189
3190 if (!types[1]->is_empty ())
3191 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u)
3192 add_builtin_candidate
3193 (candidates, code, code2, fnname, t,
3194 u, args, argtypes, flags, complain);
3195 else
3196 add_builtin_candidate
3197 (candidates, code, code2, fnname, t,
3198 NULL_TREE, args, argtypes, flags, complain);
3199 }
3200
3201 release_tree_vector (types[0]);
3202 release_tree_vector (types[1]);
3203 }
3204
3205
3206 /* If TMPL can be successfully instantiated as indicated by
3207 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
3208
3209 TMPL is the template. EXPLICIT_TARGS are any explicit template
3210 arguments. ARGLIST is the arguments provided at the call-site.
3211 This does not change ARGLIST. The RETURN_TYPE is the desired type
3212 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
3213 as for add_function_candidate. If an OBJ is supplied, FLAGS and
3214 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
3215
3216 static struct z_candidate*
add_template_candidate_real(struct z_candidate ** candidates,tree tmpl,tree ctype,tree explicit_targs,tree first_arg,const vec<tree,va_gc> * arglist,tree return_type,tree access_path,tree conversion_path,int flags,tree obj,unification_kind_t strict,tsubst_flags_t complain)3217 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
3218 tree ctype, tree explicit_targs, tree first_arg,
3219 const vec<tree, va_gc> *arglist, tree return_type,
3220 tree access_path, tree conversion_path,
3221 int flags, tree obj, unification_kind_t strict,
3222 tsubst_flags_t complain)
3223 {
3224 int ntparms = DECL_NTPARMS (tmpl);
3225 tree targs = make_tree_vec (ntparms);
3226 unsigned int len = vec_safe_length (arglist);
3227 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
3228 unsigned int skip_without_in_chrg = 0;
3229 tree first_arg_without_in_chrg = first_arg;
3230 tree *args_without_in_chrg;
3231 unsigned int nargs_without_in_chrg;
3232 unsigned int ia, ix;
3233 tree arg;
3234 struct z_candidate *cand;
3235 tree fn;
3236 struct rejection_reason *reason = NULL;
3237 int errs;
3238 conversion **convs = NULL;
3239
3240 /* We don't do deduction on the in-charge parameter, the VTT
3241 parameter or 'this'. */
3242 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
3243 {
3244 if (first_arg_without_in_chrg != NULL_TREE)
3245 first_arg_without_in_chrg = NULL_TREE;
3246 else if (return_type && strict == DEDUCE_CALL)
3247 /* We're deducing for a call to the result of a template conversion
3248 function, so the args don't contain 'this'; leave them alone. */;
3249 else
3250 ++skip_without_in_chrg;
3251 }
3252
3253 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
3254 || DECL_BASE_CONSTRUCTOR_P (tmpl))
3255 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
3256 {
3257 if (first_arg_without_in_chrg != NULL_TREE)
3258 first_arg_without_in_chrg = NULL_TREE;
3259 else
3260 ++skip_without_in_chrg;
3261 }
3262
3263 if (len < skip_without_in_chrg)
3264 return NULL;
3265
3266 if (DECL_CONSTRUCTOR_P (tmpl) && nargs == 2
3267 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (first_arg),
3268 TREE_TYPE ((*arglist)[0])))
3269 {
3270 /* 12.8/6 says, "A declaration of a constructor for a class X is
3271 ill-formed if its first parameter is of type (optionally cv-qualified)
3272 X and either there are no other parameters or else all other
3273 parameters have default arguments. A member function template is never
3274 instantiated to produce such a constructor signature."
3275
3276 So if we're trying to copy an object of the containing class, don't
3277 consider a template constructor that has a first parameter type that
3278 is just a template parameter, as we would deduce a signature that we
3279 would then reject in the code below. */
3280 if (tree firstparm = FUNCTION_FIRST_USER_PARMTYPE (tmpl))
3281 {
3282 firstparm = TREE_VALUE (firstparm);
3283 if (PACK_EXPANSION_P (firstparm))
3284 firstparm = PACK_EXPANSION_PATTERN (firstparm);
3285 if (TREE_CODE (firstparm) == TEMPLATE_TYPE_PARM)
3286 {
3287 gcc_assert (!explicit_targs);
3288 reason = invalid_copy_with_fn_template_rejection ();
3289 goto fail;
3290 }
3291 }
3292 }
3293
3294 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
3295 + (len - skip_without_in_chrg));
3296 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
3297 ia = 0;
3298 if (first_arg_without_in_chrg != NULL_TREE)
3299 {
3300 args_without_in_chrg[ia] = first_arg_without_in_chrg;
3301 ++ia;
3302 }
3303 for (ix = skip_without_in_chrg;
3304 vec_safe_iterate (arglist, ix, &arg);
3305 ++ix)
3306 {
3307 args_without_in_chrg[ia] = arg;
3308 ++ia;
3309 }
3310 gcc_assert (ia == nargs_without_in_chrg);
3311
3312 errs = errorcount+sorrycount;
3313 if (!obj)
3314 convs = alloc_conversions (nargs);
3315 fn = fn_type_unification (tmpl, explicit_targs, targs,
3316 args_without_in_chrg,
3317 nargs_without_in_chrg,
3318 return_type, strict, flags, convs,
3319 false, complain & tf_decltype);
3320
3321 if (fn == error_mark_node)
3322 {
3323 /* Don't repeat unification later if it already resulted in errors. */
3324 if (errorcount+sorrycount == errs)
3325 reason = template_unification_rejection (tmpl, explicit_targs,
3326 targs, args_without_in_chrg,
3327 nargs_without_in_chrg,
3328 return_type, strict, flags);
3329 else
3330 reason = template_unification_error_rejection ();
3331 goto fail;
3332 }
3333
3334 /* Now the explicit specifier might have been deduced; check if this
3335 declaration is explicit. If it is and we're ignoring non-converting
3336 constructors, don't add this function to the set of candidates. */
3337 if ((flags & LOOKUP_ONLYCONVERTING) && DECL_NONCONVERTING_P (fn))
3338 return NULL;
3339
3340 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
3341 {
3342 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
3343 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
3344 ctype))
3345 {
3346 /* We're trying to produce a constructor with a prohibited signature,
3347 as discussed above; handle here any cases we didn't catch then,
3348 such as X(X<T>). */
3349 reason = invalid_copy_with_fn_template_rejection ();
3350 goto fail;
3351 }
3352 }
3353
3354 if (obj != NULL_TREE)
3355 /* Aha, this is a conversion function. */
3356 cand = add_conv_candidate (candidates, fn, obj, arglist,
3357 access_path, conversion_path, complain);
3358 else
3359 cand = add_function_candidate (candidates, fn, ctype,
3360 first_arg, arglist, access_path,
3361 conversion_path, flags, convs, complain);
3362 if (DECL_TI_TEMPLATE (fn) != tmpl)
3363 /* This situation can occur if a member template of a template
3364 class is specialized. Then, instantiate_template might return
3365 an instantiation of the specialization, in which case the
3366 DECL_TI_TEMPLATE field will point at the original
3367 specialization. For example:
3368
3369 template <class T> struct S { template <class U> void f(U);
3370 template <> void f(int) {}; };
3371 S<double> sd;
3372 sd.f(3);
3373
3374 Here, TMPL will be template <class U> S<double>::f(U).
3375 And, instantiate template will give us the specialization
3376 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
3377 for this will point at template <class T> template <> S<T>::f(int),
3378 so that we can find the definition. For the purposes of
3379 overload resolution, however, we want the original TMPL. */
3380 cand->template_decl = build_template_info (tmpl, targs);
3381 else
3382 cand->template_decl = DECL_TEMPLATE_INFO (fn);
3383 cand->explicit_targs = explicit_targs;
3384
3385 return cand;
3386 fail:
3387 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
3388 access_path, conversion_path, 0, reason, flags);
3389 }
3390
3391
3392 static struct z_candidate *
add_template_candidate(struct z_candidate ** candidates,tree tmpl,tree ctype,tree explicit_targs,tree first_arg,const vec<tree,va_gc> * arglist,tree return_type,tree access_path,tree conversion_path,int flags,unification_kind_t strict,tsubst_flags_t complain)3393 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
3394 tree explicit_targs, tree first_arg,
3395 const vec<tree, va_gc> *arglist, tree return_type,
3396 tree access_path, tree conversion_path, int flags,
3397 unification_kind_t strict, tsubst_flags_t complain)
3398 {
3399 return
3400 add_template_candidate_real (candidates, tmpl, ctype,
3401 explicit_targs, first_arg, arglist,
3402 return_type, access_path, conversion_path,
3403 flags, NULL_TREE, strict, complain);
3404 }
3405
3406 /* Create an overload candidate for the conversion function template TMPL,
3407 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a
3408 pointer-to-function which will in turn be called with the argument list
3409 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
3410 passed on to implicit_conversion. */
3411
3412 static struct z_candidate *
add_template_conv_candidate(struct z_candidate ** candidates,tree tmpl,tree obj,const vec<tree,va_gc> * arglist,tree return_type,tree access_path,tree conversion_path,tsubst_flags_t complain)3413 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
3414 tree obj,
3415 const vec<tree, va_gc> *arglist,
3416 tree return_type, tree access_path,
3417 tree conversion_path, tsubst_flags_t complain)
3418 {
3419 /* Making this work broke PR 71117 and 85118, so until the committee resolves
3420 core issue 2189, let's disable this candidate if there are any call
3421 operators. */
3422 if (*candidates)
3423 return NULL;
3424
3425 return
3426 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
3427 NULL_TREE, arglist, return_type, access_path,
3428 conversion_path, 0, obj, DEDUCE_CALL,
3429 complain);
3430 }
3431
3432 /* The CANDS are the set of candidates that were considered for
3433 overload resolution. Return the set of viable candidates, or CANDS
3434 if none are viable. If any of the candidates were viable, set
3435 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3436 considered viable only if it is strictly viable. */
3437
3438 static struct z_candidate*
splice_viable(struct z_candidate * cands,bool strict_p,bool * any_viable_p)3439 splice_viable (struct z_candidate *cands,
3440 bool strict_p,
3441 bool *any_viable_p)
3442 {
3443 struct z_candidate *viable;
3444 struct z_candidate **last_viable;
3445 struct z_candidate **cand;
3446 bool found_strictly_viable = false;
3447
3448 /* Be strict inside templates, since build_over_call won't actually
3449 do the conversions to get pedwarns. */
3450 if (processing_template_decl)
3451 strict_p = true;
3452
3453 viable = NULL;
3454 last_viable = &viable;
3455 *any_viable_p = false;
3456
3457 cand = &cands;
3458 while (*cand)
3459 {
3460 struct z_candidate *c = *cand;
3461 if (!strict_p
3462 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL))
3463 {
3464 /* Be strict in the presence of a viable candidate. Also if
3465 there are template candidates, so that we get deduction errors
3466 for them instead of silently preferring a bad conversion. */
3467 strict_p = true;
3468 if (viable && !found_strictly_viable)
3469 {
3470 /* Put any spliced near matches back onto the main list so
3471 that we see them if there is no strict match. */
3472 *any_viable_p = false;
3473 *last_viable = cands;
3474 cands = viable;
3475 viable = NULL;
3476 last_viable = &viable;
3477 }
3478 }
3479
3480 if (strict_p ? c->viable == 1 : c->viable)
3481 {
3482 *last_viable = c;
3483 *cand = c->next;
3484 c->next = NULL;
3485 last_viable = &c->next;
3486 *any_viable_p = true;
3487 if (c->viable == 1)
3488 found_strictly_viable = true;
3489 }
3490 else
3491 cand = &c->next;
3492 }
3493
3494 return viable ? viable : cands;
3495 }
3496
3497 static bool
any_strictly_viable(struct z_candidate * cands)3498 any_strictly_viable (struct z_candidate *cands)
3499 {
3500 for (; cands; cands = cands->next)
3501 if (cands->viable == 1)
3502 return true;
3503 return false;
3504 }
3505
3506 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3507 words, it is about to become the "this" pointer for a member
3508 function call. Take the address of the object. */
3509
3510 static tree
build_this(tree obj)3511 build_this (tree obj)
3512 {
3513 /* In a template, we are only concerned about the type of the
3514 expression, so we can take a shortcut. */
3515 if (processing_template_decl)
3516 return build_address (obj);
3517
3518 return cp_build_addr_expr (obj, tf_warning_or_error);
3519 }
3520
3521 /* Returns true iff functions are equivalent. Equivalent functions are
3522 not '==' only if one is a function-local extern function or if
3523 both are extern "C". */
3524
3525 static inline int
equal_functions(tree fn1,tree fn2)3526 equal_functions (tree fn1, tree fn2)
3527 {
3528 if (TREE_CODE (fn1) != TREE_CODE (fn2))
3529 return 0;
3530 if (TREE_CODE (fn1) == TEMPLATE_DECL)
3531 return fn1 == fn2;
3532 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
3533 || DECL_EXTERN_C_FUNCTION_P (fn1))
3534 return decls_match (fn1, fn2);
3535 return fn1 == fn2;
3536 }
3537
3538 /* Print information about a candidate FN being rejected due to INFO. */
3539
3540 static void
print_conversion_rejection(location_t loc,struct conversion_info * info,tree fn)3541 print_conversion_rejection (location_t loc, struct conversion_info *info,
3542 tree fn)
3543 {
3544 tree from = info->from;
3545 if (!TYPE_P (from))
3546 from = lvalue_type (from);
3547 if (info->n_arg == -1)
3548 {
3549 /* Conversion of implicit `this' argument failed. */
3550 if (!TYPE_P (info->from))
3551 /* A bad conversion for 'this' must be discarding cv-quals. */
3552 inform (loc, " passing %qT as %<this%> "
3553 "argument discards qualifiers",
3554 from);
3555 else
3556 inform (loc, " no known conversion for implicit "
3557 "%<this%> parameter from %qH to %qI",
3558 from, info->to_type);
3559 }
3560 else if (!TYPE_P (info->from))
3561 {
3562 if (info->n_arg >= 0)
3563 inform (loc, " conversion of argument %d would be ill-formed:",
3564 info->n_arg + 1);
3565 perform_implicit_conversion (info->to_type, info->from,
3566 tf_warning_or_error);
3567 }
3568 else if (info->n_arg == -2)
3569 /* Conversion of conversion function return value failed. */
3570 inform (loc, " no known conversion from %qH to %qI",
3571 from, info->to_type);
3572 else
3573 {
3574 if (TREE_CODE (fn) == FUNCTION_DECL)
3575 loc = get_fndecl_argument_location (fn, info->n_arg);
3576 inform (loc, " no known conversion for argument %d from %qH to %qI",
3577 info->n_arg + 1, from, info->to_type);
3578 }
3579 }
3580
3581 /* Print information about a candidate with WANT parameters and we found
3582 HAVE. */
3583
3584 static void
print_arity_information(location_t loc,unsigned int have,unsigned int want)3585 print_arity_information (location_t loc, unsigned int have, unsigned int want)
3586 {
3587 inform_n (loc, want,
3588 " candidate expects %d argument, %d provided",
3589 " candidate expects %d arguments, %d provided",
3590 want, have);
3591 }
3592
3593 /* Print information about one overload candidate CANDIDATE. MSGSTR
3594 is the text to print before the candidate itself.
3595
3596 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3597 to have been run through gettext by the caller. This wart makes
3598 life simpler in print_z_candidates and for the translators. */
3599
3600 static void
print_z_candidate(location_t loc,const char * msgstr,struct z_candidate * candidate)3601 print_z_candidate (location_t loc, const char *msgstr,
3602 struct z_candidate *candidate)
3603 {
3604 const char *msg = (msgstr == NULL
3605 ? ""
3606 : ACONCAT ((msgstr, " ", NULL)));
3607 tree fn = candidate->fn;
3608 if (flag_new_inheriting_ctors)
3609 fn = strip_inheriting_ctors (fn);
3610 location_t cloc = location_of (fn);
3611
3612 if (identifier_p (fn))
3613 {
3614 cloc = loc;
3615 if (candidate->num_convs == 3)
3616 inform (cloc, "%s%<%D(%T, %T, %T)%> <built-in>", msg, fn,
3617 candidate->convs[0]->type,
3618 candidate->convs[1]->type,
3619 candidate->convs[2]->type);
3620 else if (candidate->num_convs == 2)
3621 inform (cloc, "%s%<%D(%T, %T)%> <built-in>", msg, fn,
3622 candidate->convs[0]->type,
3623 candidate->convs[1]->type);
3624 else
3625 inform (cloc, "%s%<%D(%T)%> <built-in>", msg, fn,
3626 candidate->convs[0]->type);
3627 }
3628 else if (TYPE_P (fn))
3629 inform (cloc, "%s%qT <conversion>", msg, fn);
3630 else if (candidate->viable == -1)
3631 inform (cloc, "%s%#qD <near match>", msg, fn);
3632 else if (DECL_DELETED_FN (fn))
3633 inform (cloc, "%s%#qD <deleted>", msg, fn);
3634 else
3635 inform (cloc, "%s%#qD", msg, fn);
3636 if (fn != candidate->fn)
3637 {
3638 cloc = location_of (candidate->fn);
3639 inform (cloc, " inherited here");
3640 }
3641 /* Give the user some information about why this candidate failed. */
3642 if (candidate->reason != NULL)
3643 {
3644 struct rejection_reason *r = candidate->reason;
3645
3646 switch (r->code)
3647 {
3648 case rr_arity:
3649 print_arity_information (cloc, r->u.arity.actual,
3650 r->u.arity.expected);
3651 break;
3652 case rr_arg_conversion:
3653 print_conversion_rejection (cloc, &r->u.conversion, fn);
3654 break;
3655 case rr_bad_arg_conversion:
3656 print_conversion_rejection (cloc, &r->u.bad_conversion, fn);
3657 break;
3658 case rr_explicit_conversion:
3659 inform (cloc, " return type %qT of explicit conversion function "
3660 "cannot be converted to %qT with a qualification "
3661 "conversion", r->u.conversion.from,
3662 r->u.conversion.to_type);
3663 break;
3664 case rr_template_conversion:
3665 inform (cloc, " conversion from return type %qT of template "
3666 "conversion function specialization to %qT is not an "
3667 "exact match", r->u.conversion.from,
3668 r->u.conversion.to_type);
3669 break;
3670 case rr_template_unification:
3671 /* We use template_unification_error_rejection if unification caused
3672 actual non-SFINAE errors, in which case we don't need to repeat
3673 them here. */
3674 if (r->u.template_unification.tmpl == NULL_TREE)
3675 {
3676 inform (cloc, " substitution of deduced template arguments "
3677 "resulted in errors seen above");
3678 break;
3679 }
3680 /* Re-run template unification with diagnostics. */
3681 inform (cloc, " template argument deduction/substitution failed:");
3682 fn_type_unification (r->u.template_unification.tmpl,
3683 r->u.template_unification.explicit_targs,
3684 (make_tree_vec
3685 (r->u.template_unification.num_targs)),
3686 r->u.template_unification.args,
3687 r->u.template_unification.nargs,
3688 r->u.template_unification.return_type,
3689 r->u.template_unification.strict,
3690 r->u.template_unification.flags,
3691 NULL, true, false);
3692 break;
3693 case rr_invalid_copy:
3694 inform (cloc,
3695 " a constructor taking a single argument of its own "
3696 "class type is invalid");
3697 break;
3698 case rr_constraint_failure:
3699 {
3700 tree tmpl = r->u.template_instantiation.tmpl;
3701 tree args = r->u.template_instantiation.targs;
3702 diagnose_constraints (cloc, tmpl, args);
3703 }
3704 break;
3705 case rr_inherited_ctor:
3706 inform (cloc, " an inherited constructor is not a candidate for "
3707 "initialization from an expression of the same or derived "
3708 "type");
3709 break;
3710 case rr_none:
3711 default:
3712 /* This candidate didn't have any issues or we failed to
3713 handle a particular code. Either way... */
3714 gcc_unreachable ();
3715 }
3716 }
3717 }
3718
3719 static void
print_z_candidates(location_t loc,struct z_candidate * candidates)3720 print_z_candidates (location_t loc, struct z_candidate *candidates)
3721 {
3722 struct z_candidate *cand1;
3723 struct z_candidate **cand2;
3724
3725 if (!candidates)
3726 return;
3727
3728 /* Remove non-viable deleted candidates. */
3729 cand1 = candidates;
3730 for (cand2 = &cand1; *cand2; )
3731 {
3732 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3733 && !(*cand2)->viable
3734 && DECL_DELETED_FN ((*cand2)->fn))
3735 *cand2 = (*cand2)->next;
3736 else
3737 cand2 = &(*cand2)->next;
3738 }
3739 /* ...if there are any non-deleted ones. */
3740 if (cand1)
3741 candidates = cand1;
3742
3743 /* There may be duplicates in the set of candidates. We put off
3744 checking this condition as long as possible, since we have no way
3745 to eliminate duplicates from a set of functions in less than n^2
3746 time. Now we are about to emit an error message, so it is more
3747 permissible to go slowly. */
3748 for (cand1 = candidates; cand1; cand1 = cand1->next)
3749 {
3750 tree fn = cand1->fn;
3751 /* Skip builtin candidates and conversion functions. */
3752 if (!DECL_P (fn))
3753 continue;
3754 cand2 = &cand1->next;
3755 while (*cand2)
3756 {
3757 if (DECL_P ((*cand2)->fn)
3758 && equal_functions (fn, (*cand2)->fn))
3759 *cand2 = (*cand2)->next;
3760 else
3761 cand2 = &(*cand2)->next;
3762 }
3763 }
3764
3765 for (; candidates; candidates = candidates->next)
3766 print_z_candidate (loc, "candidate:", candidates);
3767 }
3768
3769 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3770 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3771 the result of the conversion function to convert it to the final
3772 desired type. Merge the two sequences into a single sequence,
3773 and return the merged sequence. */
3774
3775 static conversion *
merge_conversion_sequences(conversion * user_seq,conversion * std_seq)3776 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3777 {
3778 conversion **t;
3779 bool bad = user_seq->bad_p;
3780
3781 gcc_assert (user_seq->kind == ck_user);
3782
3783 /* Find the end of the second conversion sequence. */
3784 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next))
3785 {
3786 /* The entire sequence is a user-conversion sequence. */
3787 (*t)->user_conv_p = true;
3788 if (bad)
3789 (*t)->bad_p = true;
3790 }
3791
3792 if ((*t)->rvaluedness_matches_p)
3793 /* We're binding a reference directly to the result of the conversion.
3794 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return
3795 type, but we want it back. */
3796 user_seq->type = TREE_TYPE (TREE_TYPE (user_seq->cand->fn));
3797
3798 /* Replace the identity conversion with the user conversion
3799 sequence. */
3800 *t = user_seq;
3801
3802 return std_seq;
3803 }
3804
3805 /* Handle overload resolution for initializing an object of class type from
3806 an initializer list. First we look for a suitable constructor that
3807 takes a std::initializer_list; if we don't find one, we then look for a
3808 non-list constructor.
3809
3810 Parameters are as for add_candidates, except that the arguments are in
3811 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and
3812 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3813
3814 static void
add_list_candidates(tree fns,tree first_arg,const vec<tree,va_gc> * args,tree totype,tree explicit_targs,bool template_only,tree conversion_path,tree access_path,int flags,struct z_candidate ** candidates,tsubst_flags_t complain)3815 add_list_candidates (tree fns, tree first_arg,
3816 const vec<tree, va_gc> *args, tree totype,
3817 tree explicit_targs, bool template_only,
3818 tree conversion_path, tree access_path,
3819 int flags,
3820 struct z_candidate **candidates,
3821 tsubst_flags_t complain)
3822 {
3823 gcc_assert (*candidates == NULL);
3824
3825 /* We're looking for a ctor for list-initialization. */
3826 flags |= LOOKUP_LIST_INIT_CTOR;
3827 /* And we don't allow narrowing conversions. We also use this flag to
3828 avoid the copy constructor call for copy-list-initialization. */
3829 flags |= LOOKUP_NO_NARROWING;
3830
3831 unsigned nart = num_artificial_parms_for (OVL_FIRST (fns)) - 1;
3832 tree init_list = (*args)[nart];
3833
3834 /* Always use the default constructor if the list is empty (DR 990). */
3835 if (CONSTRUCTOR_NELTS (init_list) == 0
3836 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3837 ;
3838 /* If the class has a list ctor, try passing the list as a single
3839 argument first, but only consider list ctors. */
3840 else if (TYPE_HAS_LIST_CTOR (totype))
3841 {
3842 flags |= LOOKUP_LIST_ONLY;
3843 add_candidates (fns, first_arg, args, NULL_TREE,
3844 explicit_targs, template_only, conversion_path,
3845 access_path, flags, candidates, complain);
3846 if (any_strictly_viable (*candidates))
3847 return;
3848 }
3849
3850 /* Expand the CONSTRUCTOR into a new argument vec. */
3851 vec<tree, va_gc> *new_args;
3852 vec_alloc (new_args, nart + CONSTRUCTOR_NELTS (init_list));
3853 for (unsigned i = 0; i < nart; ++i)
3854 new_args->quick_push ((*args)[i]);
3855 for (unsigned i = 0; i < CONSTRUCTOR_NELTS (init_list); ++i)
3856 new_args->quick_push (CONSTRUCTOR_ELT (init_list, i)->value);
3857
3858 /* We aren't looking for list-ctors anymore. */
3859 flags &= ~LOOKUP_LIST_ONLY;
3860 /* We allow more user-defined conversions within an init-list. */
3861 flags &= ~LOOKUP_NO_CONVERSION;
3862
3863 add_candidates (fns, first_arg, new_args, NULL_TREE,
3864 explicit_targs, template_only, conversion_path,
3865 access_path, flags, candidates, complain);
3866 }
3867
3868 /* Returns the best overload candidate to perform the requested
3869 conversion. This function is used for three the overloading situations
3870 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3871 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as
3872 per [dcl.init.ref], so we ignore temporary bindings. */
3873
3874 static struct z_candidate *
build_user_type_conversion_1(tree totype,tree expr,int flags,tsubst_flags_t complain)3875 build_user_type_conversion_1 (tree totype, tree expr, int flags,
3876 tsubst_flags_t complain)
3877 {
3878 struct z_candidate *candidates, *cand;
3879 tree fromtype;
3880 tree ctors = NULL_TREE;
3881 tree conv_fns = NULL_TREE;
3882 conversion *conv = NULL;
3883 tree first_arg = NULL_TREE;
3884 vec<tree, va_gc> *args = NULL;
3885 bool any_viable_p;
3886 int convflags;
3887
3888 if (!expr)
3889 return NULL;
3890
3891 fromtype = TREE_TYPE (expr);
3892
3893 /* We represent conversion within a hierarchy using RVALUE_CONV and
3894 BASE_CONV, as specified by [over.best.ics]; these become plain
3895 constructor calls, as specified in [dcl.init]. */
3896 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3897 || !DERIVED_FROM_P (totype, fromtype));
3898
3899 if (CLASS_TYPE_P (totype))
3900 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3901 creating a garbage BASELINK; constructors can't be inherited. */
3902 ctors = get_class_binding (totype, complete_ctor_identifier);
3903
3904 if (MAYBE_CLASS_TYPE_P (fromtype))
3905 {
3906 tree to_nonref = non_reference (totype);
3907 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3908 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3909 && DERIVED_FROM_P (to_nonref, fromtype)))
3910 {
3911 /* [class.conv.fct] A conversion function is never used to
3912 convert a (possibly cv-qualified) object to the (possibly
3913 cv-qualified) same object type (or a reference to it), to a
3914 (possibly cv-qualified) base class of that type (or a
3915 reference to it)... */
3916 }
3917 else
3918 conv_fns = lookup_conversions (fromtype);
3919 }
3920
3921 candidates = 0;
3922 flags |= LOOKUP_NO_CONVERSION;
3923 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3924 flags |= LOOKUP_NO_NARROWING;
3925
3926 /* It's OK to bind a temporary for converting constructor arguments, but
3927 not in converting the return value of a conversion operator. */
3928 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION
3929 | (flags & LOOKUP_NO_NARROWING));
3930 flags &= ~LOOKUP_NO_TEMP_BIND;
3931
3932 if (ctors)
3933 {
3934 int ctorflags = flags;
3935
3936 first_arg = build_dummy_object (totype);
3937
3938 /* We should never try to call the abstract or base constructor
3939 from here. */
3940 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_FIRST (ctors))
3941 && !DECL_HAS_VTT_PARM_P (OVL_FIRST (ctors)));
3942
3943 args = make_tree_vector_single (expr);
3944 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3945 {
3946 /* List-initialization. */
3947 add_list_candidates (ctors, first_arg, args, totype, NULL_TREE,
3948 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3949 ctorflags, &candidates, complain);
3950 }
3951 else
3952 {
3953 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3954 TYPE_BINFO (totype), TYPE_BINFO (totype),
3955 ctorflags, &candidates, complain);
3956 }
3957
3958 for (cand = candidates; cand; cand = cand->next)
3959 {
3960 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3961
3962 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3963 set, then this is copy-initialization. In that case, "The
3964 result of the call is then used to direct-initialize the
3965 object that is the destination of the copy-initialization."
3966 [dcl.init]
3967
3968 We represent this in the conversion sequence with an
3969 rvalue conversion, which means a constructor call. */
3970 if (!TYPE_REF_P (totype)
3971 && !(convflags & LOOKUP_NO_TEMP_BIND))
3972 cand->second_conv
3973 = build_conv (ck_rvalue, totype, cand->second_conv);
3974 }
3975 }
3976
3977 if (conv_fns)
3978 {
3979 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3980 first_arg = CONSTRUCTOR_ELT (expr, 0)->value;
3981 else
3982 first_arg = expr;
3983 }
3984
3985 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3986 {
3987 tree conversion_path = TREE_PURPOSE (conv_fns);
3988 struct z_candidate *old_candidates;
3989
3990 /* If we are called to convert to a reference type, we are trying to
3991 find a direct binding, so don't even consider temporaries. If
3992 we don't find a direct binding, the caller will try again to
3993 look for a temporary binding. */
3994 if (TYPE_REF_P (totype))
3995 convflags |= LOOKUP_NO_TEMP_BIND;
3996
3997 old_candidates = candidates;
3998 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3999 NULL_TREE, false,
4000 conversion_path, TYPE_BINFO (fromtype),
4001 flags, &candidates, complain);
4002
4003 for (cand = candidates; cand != old_candidates; cand = cand->next)
4004 {
4005 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
4006 conversion *ics
4007 = implicit_conversion (totype,
4008 rettype,
4009 0,
4010 /*c_cast_p=*/false, convflags,
4011 complain);
4012
4013 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
4014 copy-initialization. In that case, "The result of the
4015 call is then used to direct-initialize the object that is
4016 the destination of the copy-initialization." [dcl.init]
4017
4018 We represent this in the conversion sequence with an
4019 rvalue conversion, which means a constructor call. But
4020 don't add a second rvalue conversion if there's already
4021 one there. Which there really shouldn't be, but it's
4022 harmless since we'd add it here anyway. */
4023 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
4024 && !(convflags & LOOKUP_NO_TEMP_BIND))
4025 ics = build_conv (ck_rvalue, totype, ics);
4026
4027 cand->second_conv = ics;
4028
4029 if (!ics)
4030 {
4031 cand->viable = 0;
4032 cand->reason = arg_conversion_rejection (NULL_TREE, -2,
4033 rettype, totype,
4034 EXPR_LOCATION (expr));
4035 }
4036 else if (TYPE_REF_P (totype) && !ics->rvaluedness_matches_p
4037 /* Limit this to non-templates for now (PR90546). */
4038 && !cand->template_decl
4039 && TREE_CODE (TREE_TYPE (totype)) != FUNCTION_TYPE)
4040 {
4041 /* If we are called to convert to a reference type, we are trying
4042 to find a direct binding per [over.match.ref], so rvaluedness
4043 must match for non-functions. */
4044 cand->viable = 0;
4045 }
4046 else if (DECL_NONCONVERTING_P (cand->fn)
4047 && ics->rank > cr_exact)
4048 {
4049 /* 13.3.1.5: For direct-initialization, those explicit
4050 conversion functions that are not hidden within S and
4051 yield type T or a type that can be converted to type T
4052 with a qualification conversion (4.4) are also candidate
4053 functions. */
4054 /* 13.3.1.6 doesn't have a parallel restriction, but it should;
4055 I've raised this issue with the committee. --jason 9/2011 */
4056 cand->viable = -1;
4057 cand->reason = explicit_conversion_rejection (rettype, totype);
4058 }
4059 else if (cand->viable == 1 && ics->bad_p)
4060 {
4061 cand->viable = -1;
4062 cand->reason
4063 = bad_arg_conversion_rejection (NULL_TREE, -2,
4064 rettype, totype,
4065 EXPR_LOCATION (expr));
4066 }
4067 else if (primary_template_specialization_p (cand->fn)
4068 && ics->rank > cr_exact)
4069 {
4070 /* 13.3.3.1.2: If the user-defined conversion is specified by
4071 a specialization of a conversion function template, the
4072 second standard conversion sequence shall have exact match
4073 rank. */
4074 cand->viable = -1;
4075 cand->reason = template_conversion_rejection (rettype, totype);
4076 }
4077 }
4078 }
4079
4080 candidates = splice_viable (candidates, false, &any_viable_p);
4081 if (!any_viable_p)
4082 {
4083 if (args)
4084 release_tree_vector (args);
4085 return NULL;
4086 }
4087
4088 cand = tourney (candidates, complain);
4089 if (cand == NULL)
4090 {
4091 if (complain & tf_error)
4092 {
4093 auto_diagnostic_group d;
4094 error ("conversion from %qH to %qI is ambiguous",
4095 fromtype, totype);
4096 print_z_candidates (location_of (expr), candidates);
4097 }
4098
4099 cand = candidates; /* any one will do */
4100 cand->second_conv = build_ambiguous_conv (totype, expr);
4101 cand->second_conv->user_conv_p = true;
4102 if (!any_strictly_viable (candidates))
4103 cand->second_conv->bad_p = true;
4104 if (flags & LOOKUP_ONLYCONVERTING)
4105 cand->second_conv->need_temporary_p = true;
4106 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
4107 ambiguous conversion is no worse than another user-defined
4108 conversion. */
4109
4110 return cand;
4111 }
4112
4113 tree convtype;
4114 if (!DECL_CONSTRUCTOR_P (cand->fn))
4115 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn)));
4116 else if (cand->second_conv->kind == ck_rvalue)
4117 /* DR 5: [in the first step of copy-initialization]...if the function
4118 is a constructor, the call initializes a temporary of the
4119 cv-unqualified version of the destination type. */
4120 convtype = cv_unqualified (totype);
4121 else
4122 convtype = totype;
4123 /* Build the user conversion sequence. */
4124 conv = build_conv
4125 (ck_user,
4126 convtype,
4127 build_identity_conv (TREE_TYPE (expr), expr));
4128 conv->cand = cand;
4129 if (cand->viable == -1)
4130 conv->bad_p = true;
4131
4132 /* We're performing the maybe-rvalue overload resolution and
4133 a conversion function is in play. Reject converting the return
4134 value of the conversion function to a base class. */
4135 if ((flags & LOOKUP_PREFER_RVALUE) && !DECL_CONSTRUCTOR_P (cand->fn))
4136 for (conversion *t = cand->second_conv; t; t = next_conversion (t))
4137 if (t->kind == ck_base)
4138 return NULL;
4139
4140 /* Remember that this was a list-initialization. */
4141 if (flags & LOOKUP_NO_NARROWING)
4142 conv->check_narrowing = true;
4143
4144 /* Combine it with the second conversion sequence. */
4145 cand->second_conv = merge_conversion_sequences (conv,
4146 cand->second_conv);
4147
4148 return cand;
4149 }
4150
4151 /* Wrapper for above. */
4152
4153 tree
build_user_type_conversion(tree totype,tree expr,int flags,tsubst_flags_t complain)4154 build_user_type_conversion (tree totype, tree expr, int flags,
4155 tsubst_flags_t complain)
4156 {
4157 struct z_candidate *cand;
4158 tree ret;
4159
4160 bool subtime = timevar_cond_start (TV_OVERLOAD);
4161 cand = build_user_type_conversion_1 (totype, expr, flags, complain);
4162
4163 if (cand)
4164 {
4165 if (cand->second_conv->kind == ck_ambig)
4166 ret = error_mark_node;
4167 else
4168 {
4169 expr = convert_like (cand->second_conv, expr, complain);
4170 ret = convert_from_reference (expr);
4171 }
4172 }
4173 else
4174 ret = NULL_TREE;
4175
4176 timevar_cond_stop (TV_OVERLOAD, subtime);
4177 return ret;
4178 }
4179
4180 /* Worker for build_converted_constant_expr. */
4181
4182 static tree
build_converted_constant_expr_internal(tree type,tree expr,int flags,tsubst_flags_t complain)4183 build_converted_constant_expr_internal (tree type, tree expr,
4184 int flags, tsubst_flags_t complain)
4185 {
4186 conversion *conv;
4187 void *p;
4188 tree t;
4189 location_t loc = cp_expr_loc_or_loc (expr, input_location);
4190
4191 if (error_operand_p (expr))
4192 return error_mark_node;
4193
4194 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4195 p = conversion_obstack_alloc (0);
4196
4197 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
4198 /*c_cast_p=*/false, flags, complain);
4199
4200 /* A converted constant expression of type T is an expression, implicitly
4201 converted to type T, where the converted expression is a constant
4202 expression and the implicit conversion sequence contains only
4203
4204 * user-defined conversions,
4205 * lvalue-to-rvalue conversions (7.1),
4206 * array-to-pointer conversions (7.2),
4207 * function-to-pointer conversions (7.3),
4208 * qualification conversions (7.5),
4209 * integral promotions (7.6),
4210 * integral conversions (7.8) other than narrowing conversions (11.6.4),
4211 * null pointer conversions (7.11) from std::nullptr_t,
4212 * null member pointer conversions (7.12) from std::nullptr_t, and
4213 * function pointer conversions (7.13),
4214
4215 and where the reference binding (if any) binds directly. */
4216
4217 for (conversion *c = conv;
4218 conv && c->kind != ck_identity;
4219 c = next_conversion (c))
4220 {
4221 switch (c->kind)
4222 {
4223 /* A conversion function is OK. If it isn't constexpr, we'll
4224 complain later that the argument isn't constant. */
4225 case ck_user:
4226 /* The lvalue-to-rvalue conversion is OK. */
4227 case ck_rvalue:
4228 /* Array-to-pointer and function-to-pointer. */
4229 case ck_lvalue:
4230 /* Function pointer conversions. */
4231 case ck_fnptr:
4232 /* Qualification conversions. */
4233 case ck_qual:
4234 break;
4235
4236 case ck_ref_bind:
4237 if (c->need_temporary_p)
4238 {
4239 if (complain & tf_error)
4240 error_at (loc, "initializing %qH with %qI in converted "
4241 "constant expression does not bind directly",
4242 type, next_conversion (c)->type);
4243 conv = NULL;
4244 }
4245 break;
4246
4247 case ck_base:
4248 case ck_pmem:
4249 case ck_ptr:
4250 case ck_std:
4251 t = next_conversion (c)->type;
4252 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t)
4253 && INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4254 /* Integral promotion or conversion. */
4255 break;
4256 if (NULLPTR_TYPE_P (t))
4257 /* Conversion from nullptr to pointer or pointer-to-member. */
4258 break;
4259
4260 if (complain & tf_error)
4261 error_at (loc, "conversion from %qH to %qI in a "
4262 "converted constant expression", t, type);
4263 /* fall through. */
4264
4265 default:
4266 conv = NULL;
4267 break;
4268 }
4269 }
4270
4271 /* Avoid confusing convert_nontype_argument by introducing
4272 a redundant conversion to the same reference type. */
4273 if (conv && conv->kind == ck_ref_bind
4274 && REFERENCE_REF_P (expr))
4275 {
4276 tree ref = TREE_OPERAND (expr, 0);
4277 if (same_type_p (type, TREE_TYPE (ref)))
4278 return ref;
4279 }
4280
4281 if (conv)
4282 {
4283 /* Don't copy a class non-type template parameter. */
4284 if (CLASS_TYPE_P (type) && conv->kind == ck_rvalue
4285 && TREE_CODE (expr) == VIEW_CONVERT_EXPR
4286 && TREE_CODE (TREE_OPERAND (expr, 0)) == TEMPLATE_PARM_INDEX)
4287 conv = next_conversion (conv);
4288
4289 conv->check_narrowing = true;
4290 conv->check_narrowing_const_only = true;
4291 expr = convert_like (conv, expr, complain);
4292 }
4293 else
4294 {
4295 if (complain & tf_error)
4296 error_at (loc, "could not convert %qE from %qH to %qI", expr,
4297 TREE_TYPE (expr), type);
4298 expr = error_mark_node;
4299 }
4300
4301 /* Free all the conversions we allocated. */
4302 obstack_free (&conversion_obstack, p);
4303
4304 return expr;
4305 }
4306
4307 /* Subroutine of convert_nontype_argument.
4308
4309 EXPR is an expression used in a context that requires a converted
4310 constant-expression, such as a template non-type parameter. Do any
4311 necessary conversions (that are permitted for converted
4312 constant-expressions) to convert it to the desired type.
4313
4314 This function doesn't consider explicit conversion functions. If
4315 you mean to use "a contextually converted constant expression of type
4316 bool", use build_converted_constant_bool_expr.
4317
4318 If conversion is successful, returns the converted expression;
4319 otherwise, returns error_mark_node. */
4320
4321 tree
build_converted_constant_expr(tree type,tree expr,tsubst_flags_t complain)4322 build_converted_constant_expr (tree type, tree expr, tsubst_flags_t complain)
4323 {
4324 return build_converted_constant_expr_internal (type, expr, LOOKUP_IMPLICIT,
4325 complain);
4326 }
4327
4328 /* Used to create "a contextually converted constant expression of type
4329 bool". This differs from build_converted_constant_expr in that it
4330 also considers explicit conversion functions. */
4331
4332 tree
build_converted_constant_bool_expr(tree expr,tsubst_flags_t complain)4333 build_converted_constant_bool_expr (tree expr, tsubst_flags_t complain)
4334 {
4335 return build_converted_constant_expr_internal (boolean_type_node, expr,
4336 LOOKUP_NORMAL, complain);
4337 }
4338
4339 /* Do any initial processing on the arguments to a function call. */
4340
4341 static vec<tree, va_gc> *
resolve_args(vec<tree,va_gc> * args,tsubst_flags_t complain)4342 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain)
4343 {
4344 unsigned int ix;
4345 tree arg;
4346
4347 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
4348 {
4349 if (error_operand_p (arg))
4350 return NULL;
4351 else if (VOID_TYPE_P (TREE_TYPE (arg)))
4352 {
4353 if (complain & tf_error)
4354 error ("invalid use of void expression");
4355 return NULL;
4356 }
4357 else if (invalid_nonstatic_memfn_p (EXPR_LOCATION (arg), arg, complain))
4358 return NULL;
4359 }
4360 return args;
4361 }
4362
4363 /* Perform overload resolution on FN, which is called with the ARGS.
4364
4365 Return the candidate function selected by overload resolution, or
4366 NULL if the event that overload resolution failed. In the case
4367 that overload resolution fails, *CANDIDATES will be the set of
4368 candidates considered, and ANY_VIABLE_P will be set to true or
4369 false to indicate whether or not any of the candidates were
4370 viable.
4371
4372 The ARGS should already have gone through RESOLVE_ARGS before this
4373 function is called. */
4374
4375 static struct z_candidate *
perform_overload_resolution(tree fn,const vec<tree,va_gc> * args,struct z_candidate ** candidates,bool * any_viable_p,tsubst_flags_t complain)4376 perform_overload_resolution (tree fn,
4377 const vec<tree, va_gc> *args,
4378 struct z_candidate **candidates,
4379 bool *any_viable_p, tsubst_flags_t complain)
4380 {
4381 struct z_candidate *cand;
4382 tree explicit_targs;
4383 int template_only;
4384
4385 bool subtime = timevar_cond_start (TV_OVERLOAD);
4386
4387 explicit_targs = NULL_TREE;
4388 template_only = 0;
4389
4390 *candidates = NULL;
4391 *any_viable_p = true;
4392
4393 /* Check FN. */
4394 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4395 || TREE_CODE (fn) == TEMPLATE_DECL
4396 || TREE_CODE (fn) == OVERLOAD
4397 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
4398
4399 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4400 {
4401 explicit_targs = TREE_OPERAND (fn, 1);
4402 fn = TREE_OPERAND (fn, 0);
4403 template_only = 1;
4404 }
4405
4406 /* Add the various candidate functions. */
4407 add_candidates (fn, NULL_TREE, args, NULL_TREE,
4408 explicit_targs, template_only,
4409 /*conversion_path=*/NULL_TREE,
4410 /*access_path=*/NULL_TREE,
4411 LOOKUP_NORMAL,
4412 candidates, complain);
4413
4414 *candidates = splice_viable (*candidates, false, any_viable_p);
4415 if (*any_viable_p)
4416 cand = tourney (*candidates, complain);
4417 else
4418 cand = NULL;
4419
4420 timevar_cond_stop (TV_OVERLOAD, subtime);
4421 return cand;
4422 }
4423
4424 /* Print an error message about being unable to build a call to FN with
4425 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
4426 be located; CANDIDATES is a possibly empty list of such
4427 functions. */
4428
4429 static void
print_error_for_call_failure(tree fn,vec<tree,va_gc> * args,struct z_candidate * candidates)4430 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args,
4431 struct z_candidate *candidates)
4432 {
4433 tree targs = NULL_TREE;
4434 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4435 {
4436 targs = TREE_OPERAND (fn, 1);
4437 fn = TREE_OPERAND (fn, 0);
4438 }
4439 tree name = OVL_NAME (fn);
4440 location_t loc = location_of (name);
4441 if (targs)
4442 name = lookup_template_function (name, targs);
4443
4444 auto_diagnostic_group d;
4445 if (!any_strictly_viable (candidates))
4446 error_at (loc, "no matching function for call to %<%D(%A)%>",
4447 name, build_tree_list_vec (args));
4448 else
4449 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
4450 name, build_tree_list_vec (args));
4451 if (candidates)
4452 print_z_candidates (loc, candidates);
4453 }
4454
4455 /* Return an expression for a call to FN (a namespace-scope function,
4456 or a static member function) with the ARGS. This may change
4457 ARGS. */
4458
4459 tree
build_new_function_call(tree fn,vec<tree,va_gc> ** args,tsubst_flags_t complain)4460 build_new_function_call (tree fn, vec<tree, va_gc> **args,
4461 tsubst_flags_t complain)
4462 {
4463 struct z_candidate *candidates, *cand;
4464 bool any_viable_p;
4465 void *p;
4466 tree result;
4467
4468 if (args != NULL && *args != NULL)
4469 {
4470 *args = resolve_args (*args, complain);
4471 if (*args == NULL)
4472 return error_mark_node;
4473 }
4474
4475 if (flag_tm)
4476 tm_malloc_replacement (fn);
4477
4478 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4479 p = conversion_obstack_alloc (0);
4480
4481 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p,
4482 complain);
4483
4484 if (!cand)
4485 {
4486 if (complain & tf_error)
4487 {
4488 // If there is a single (non-viable) function candidate,
4489 // let the error be diagnosed by cp_build_function_call_vec.
4490 if (!any_viable_p && candidates && ! candidates->next
4491 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
4492 return cp_build_function_call_vec (candidates->fn, args, complain);
4493
4494 // Otherwise, emit notes for non-viable candidates.
4495 print_error_for_call_failure (fn, *args, candidates);
4496 }
4497 result = error_mark_node;
4498 }
4499 else
4500 {
4501 int flags = LOOKUP_NORMAL;
4502 /* If fn is template_id_expr, the call has explicit template arguments
4503 (e.g. func<int>(5)), communicate this info to build_over_call
4504 through flags so that later we can use it to decide whether to warn
4505 about peculiar null pointer conversion. */
4506 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4507 {
4508 /* If overload resolution selects a specialization of a
4509 function concept for non-dependent template arguments,
4510 the expression is true if the constraints are satisfied
4511 and false otherwise.
4512
4513 NOTE: This is an extension of Concepts Lite TS that
4514 allows constraints to be used in expressions. */
4515 if (flag_concepts && !processing_template_decl)
4516 {
4517 tree tmpl = DECL_TI_TEMPLATE (cand->fn);
4518 tree targs = DECL_TI_ARGS (cand->fn);
4519 tree decl = DECL_TEMPLATE_RESULT (tmpl);
4520 if (DECL_DECLARED_CONCEPT_P (decl))
4521 return evaluate_function_concept (decl, targs);
4522 }
4523
4524 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
4525 }
4526
4527 result = build_over_call (cand, flags, complain);
4528 }
4529
4530 /* Free all the conversions we allocated. */
4531 obstack_free (&conversion_obstack, p);
4532
4533 return result;
4534 }
4535
4536 /* Build a call to a global operator new. FNNAME is the name of the
4537 operator (either "operator new" or "operator new[]") and ARGS are
4538 the arguments provided. This may change ARGS. *SIZE points to the
4539 total number of bytes required by the allocation, and is updated if
4540 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
4541 be used. If this function determines that no cookie should be
4542 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK
4543 is not NULL_TREE, it is evaluated before calculating the final
4544 array size, and if it fails, the array size is replaced with
4545 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN
4546 is non-NULL, it will be set, upon return, to the allocation
4547 function called. */
4548
4549 tree
build_operator_new_call(tree fnname,vec<tree,va_gc> ** args,tree * size,tree * cookie_size,tree align_arg,tree size_check,tree * fn,tsubst_flags_t complain)4550 build_operator_new_call (tree fnname, vec<tree, va_gc> **args,
4551 tree *size, tree *cookie_size,
4552 tree align_arg, tree size_check,
4553 tree *fn, tsubst_flags_t complain)
4554 {
4555 tree original_size = *size;
4556 tree fns;
4557 struct z_candidate *candidates;
4558 struct z_candidate *cand = NULL;
4559 bool any_viable_p;
4560
4561 if (fn)
4562 *fn = NULL_TREE;
4563 /* Set to (size_t)-1 if the size check fails. */
4564 if (size_check != NULL_TREE)
4565 {
4566 tree errval = TYPE_MAX_VALUE (sizetype);
4567 if (cxx_dialect >= cxx11 && flag_exceptions)
4568 errval = throw_bad_array_new_length ();
4569 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4570 original_size, errval);
4571 }
4572 vec_safe_insert (*args, 0, *size);
4573 *args = resolve_args (*args, complain);
4574 if (*args == NULL)
4575 return error_mark_node;
4576
4577 /* Based on:
4578
4579 [expr.new]
4580
4581 If this lookup fails to find the name, or if the allocated type
4582 is not a class type, the allocation function's name is looked
4583 up in the global scope.
4584
4585 we disregard block-scope declarations of "operator new". */
4586 fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0);
4587 fns = lookup_arg_dependent (fnname, fns, *args);
4588
4589 if (align_arg)
4590 {
4591 vec<tree, va_gc>* align_args
4592 = vec_copy_and_insert (*args, align_arg, 1);
4593 cand = perform_overload_resolution (fns, align_args, &candidates,
4594 &any_viable_p, tf_none);
4595 if (cand)
4596 *args = align_args;
4597 /* If no aligned allocation function matches, try again without the
4598 alignment. */
4599 }
4600
4601 /* Figure out what function is being called. */
4602 if (!cand)
4603 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p,
4604 complain);
4605
4606 /* If no suitable function could be found, issue an error message
4607 and give up. */
4608 if (!cand)
4609 {
4610 if (complain & tf_error)
4611 print_error_for_call_failure (fns, *args, candidates);
4612 return error_mark_node;
4613 }
4614
4615 /* If a cookie is required, add some extra space. Whether
4616 or not a cookie is required cannot be determined until
4617 after we know which function was called. */
4618 if (*cookie_size)
4619 {
4620 bool use_cookie = true;
4621 tree arg_types;
4622
4623 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
4624 /* Skip the size_t parameter. */
4625 arg_types = TREE_CHAIN (arg_types);
4626 /* Check the remaining parameters (if any). */
4627 if (arg_types
4628 && TREE_CHAIN (arg_types) == void_list_node
4629 && same_type_p (TREE_VALUE (arg_types),
4630 ptr_type_node))
4631 use_cookie = false;
4632 /* If we need a cookie, adjust the number of bytes allocated. */
4633 if (use_cookie)
4634 {
4635 /* Update the total size. */
4636 *size = size_binop (PLUS_EXPR, original_size, *cookie_size);
4637 if (size_check)
4638 {
4639 /* Set to (size_t)-1 if the size check fails. */
4640 gcc_assert (size_check != NULL_TREE);
4641 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4642 *size, TYPE_MAX_VALUE (sizetype));
4643 }
4644 /* Update the argument list to reflect the adjusted size. */
4645 (**args)[0] = *size;
4646 }
4647 else
4648 *cookie_size = NULL_TREE;
4649 }
4650
4651 /* Tell our caller which function we decided to call. */
4652 if (fn)
4653 *fn = cand->fn;
4654
4655 /* Build the CALL_EXPR. */
4656 return build_over_call (cand, LOOKUP_NORMAL, complain);
4657 }
4658
4659 /* Build a new call to operator(). This may change ARGS. */
4660
4661 static tree
build_op_call_1(tree obj,vec<tree,va_gc> ** args,tsubst_flags_t complain)4662 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4663 {
4664 struct z_candidate *candidates = 0, *cand;
4665 tree fns, convs, first_mem_arg = NULL_TREE;
4666 bool any_viable_p;
4667 tree result = NULL_TREE;
4668 void *p;
4669
4670 obj = mark_lvalue_use (obj);
4671
4672 if (error_operand_p (obj))
4673 return error_mark_node;
4674
4675 tree type = TREE_TYPE (obj);
4676
4677 obj = prep_operand (obj);
4678
4679 if (TYPE_PTRMEMFUNC_P (type))
4680 {
4681 if (complain & tf_error)
4682 /* It's no good looking for an overloaded operator() on a
4683 pointer-to-member-function. */
4684 error ("pointer-to-member function %qE cannot be called without "
4685 "an object; consider using %<.*%> or %<->*%>", obj);
4686 return error_mark_node;
4687 }
4688
4689 if (TYPE_BINFO (type))
4690 {
4691 fns = lookup_fnfields (TYPE_BINFO (type), call_op_identifier, 1);
4692 if (fns == error_mark_node)
4693 return error_mark_node;
4694 }
4695 else
4696 fns = NULL_TREE;
4697
4698 if (args != NULL && *args != NULL)
4699 {
4700 *args = resolve_args (*args, complain);
4701 if (*args == NULL)
4702 return error_mark_node;
4703 }
4704
4705 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4706 p = conversion_obstack_alloc (0);
4707
4708 if (fns)
4709 {
4710 first_mem_arg = obj;
4711
4712 add_candidates (BASELINK_FUNCTIONS (fns),
4713 first_mem_arg, *args, NULL_TREE,
4714 NULL_TREE, false,
4715 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
4716 LOOKUP_NORMAL, &candidates, complain);
4717 }
4718
4719 convs = lookup_conversions (type);
4720
4721 for (; convs; convs = TREE_CHAIN (convs))
4722 {
4723 tree totype = TREE_TYPE (convs);
4724
4725 if (TYPE_PTRFN_P (totype)
4726 || TYPE_REFFN_P (totype)
4727 || (TYPE_REF_P (totype)
4728 && TYPE_PTRFN_P (TREE_TYPE (totype))))
4729 for (ovl_iterator iter (TREE_VALUE (convs)); iter; ++iter)
4730 {
4731 tree fn = *iter;
4732
4733 if (DECL_NONCONVERTING_P (fn))
4734 continue;
4735
4736 if (TREE_CODE (fn) == TEMPLATE_DECL)
4737 add_template_conv_candidate
4738 (&candidates, fn, obj, *args, totype,
4739 /*access_path=*/NULL_TREE,
4740 /*conversion_path=*/NULL_TREE, complain);
4741 else
4742 add_conv_candidate (&candidates, fn, obj,
4743 *args, /*conversion_path=*/NULL_TREE,
4744 /*access_path=*/NULL_TREE, complain);
4745 }
4746 }
4747
4748 /* Be strict here because if we choose a bad conversion candidate, the
4749 errors we get won't mention the call context. */
4750 candidates = splice_viable (candidates, true, &any_viable_p);
4751 if (!any_viable_p)
4752 {
4753 if (complain & tf_error)
4754 {
4755 auto_diagnostic_group d;
4756 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
4757 build_tree_list_vec (*args));
4758 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4759 }
4760 result = error_mark_node;
4761 }
4762 else
4763 {
4764 cand = tourney (candidates, complain);
4765 if (cand == 0)
4766 {
4767 if (complain & tf_error)
4768 {
4769 auto_diagnostic_group d;
4770 error ("call of %<(%T) (%A)%> is ambiguous",
4771 TREE_TYPE (obj), build_tree_list_vec (*args));
4772 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4773 }
4774 result = error_mark_node;
4775 }
4776 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
4777 && DECL_OVERLOADED_OPERATOR_P (cand->fn)
4778 && DECL_OVERLOADED_OPERATOR_IS (cand->fn, CALL_EXPR))
4779 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4780 else
4781 {
4782 if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4783 obj = convert_like_with_context (cand->convs[0], obj, cand->fn,
4784 -1, complain);
4785 else
4786 {
4787 gcc_checking_assert (TYPE_P (cand->fn));
4788 obj = convert_like (cand->convs[0], obj, complain);
4789 }
4790 obj = convert_from_reference (obj);
4791 result = cp_build_function_call_vec (obj, args, complain);
4792 }
4793 }
4794
4795 /* Free all the conversions we allocated. */
4796 obstack_free (&conversion_obstack, p);
4797
4798 return result;
4799 }
4800
4801 /* Wrapper for above. */
4802
4803 tree
build_op_call(tree obj,vec<tree,va_gc> ** args,tsubst_flags_t complain)4804 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4805 {
4806 tree ret;
4807 bool subtime = timevar_cond_start (TV_OVERLOAD);
4808 ret = build_op_call_1 (obj, args, complain);
4809 timevar_cond_stop (TV_OVERLOAD, subtime);
4810 return ret;
4811 }
4812
4813 /* Called by op_error to prepare format strings suitable for the error
4814 function. It concatenates a prefix (controlled by MATCH), ERRMSG,
4815 and a suffix (controlled by NTYPES). */
4816
4817 static const char *
op_error_string(const char * errmsg,int ntypes,bool match)4818 op_error_string (const char *errmsg, int ntypes, bool match)
4819 {
4820 const char *msg;
4821
4822 const char *msgp = concat (match ? G_("ambiguous overload for ")
4823 : G_("no match for "), errmsg, NULL);
4824
4825 if (ntypes == 3)
4826 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL);
4827 else if (ntypes == 2)
4828 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL);
4829 else
4830 msg = concat (msgp, G_(" (operand type is %qT)"), NULL);
4831
4832 return msg;
4833 }
4834
4835 static void
op_error(const op_location_t & loc,enum tree_code code,enum tree_code code2,tree arg1,tree arg2,tree arg3,bool match)4836 op_error (const op_location_t &loc,
4837 enum tree_code code, enum tree_code code2,
4838 tree arg1, tree arg2, tree arg3, bool match)
4839 {
4840 bool assop = code == MODIFY_EXPR;
4841 const char *opname = OVL_OP_INFO (assop, assop ? code2 : code)->name;
4842
4843 switch (code)
4844 {
4845 case COND_EXPR:
4846 if (flag_diagnostics_show_caret)
4847 error_at (loc, op_error_string (G_("ternary %<operator?:%>"),
4848 3, match),
4849 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4850 else
4851 error_at (loc, op_error_string (G_("ternary %<operator?:%> "
4852 "in %<%E ? %E : %E%>"), 3, match),
4853 arg1, arg2, arg3,
4854 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4855 break;
4856
4857 case POSTINCREMENT_EXPR:
4858 case POSTDECREMENT_EXPR:
4859 if (flag_diagnostics_show_caret)
4860 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4861 opname, TREE_TYPE (arg1));
4862 else
4863 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"),
4864 1, match),
4865 opname, arg1, opname, TREE_TYPE (arg1));
4866 break;
4867
4868 case ARRAY_REF:
4869 if (flag_diagnostics_show_caret)
4870 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match),
4871 TREE_TYPE (arg1), TREE_TYPE (arg2));
4872 else
4873 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"),
4874 2, match),
4875 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2));
4876 break;
4877
4878 case REALPART_EXPR:
4879 case IMAGPART_EXPR:
4880 if (flag_diagnostics_show_caret)
4881 error_at (loc, op_error_string (G_("%qs"), 1, match),
4882 opname, TREE_TYPE (arg1));
4883 else
4884 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match),
4885 opname, opname, arg1, TREE_TYPE (arg1));
4886 break;
4887
4888 default:
4889 if (arg2)
4890 if (flag_diagnostics_show_caret)
4891 {
4892 binary_op_rich_location richloc (loc, arg1, arg2, true);
4893 error_at (&richloc,
4894 op_error_string (G_("%<operator%s%>"), 2, match),
4895 opname, TREE_TYPE (arg1), TREE_TYPE (arg2));
4896 }
4897 else
4898 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"),
4899 2, match),
4900 opname, arg1, opname, arg2,
4901 TREE_TYPE (arg1), TREE_TYPE (arg2));
4902 else
4903 if (flag_diagnostics_show_caret)
4904 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4905 opname, TREE_TYPE (arg1));
4906 else
4907 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"),
4908 1, match),
4909 opname, opname, arg1, TREE_TYPE (arg1));
4910 break;
4911 }
4912 }
4913
4914 /* Return the implicit conversion sequence that could be used to
4915 convert E1 to E2 in [expr.cond]. */
4916
4917 static conversion *
conditional_conversion(tree e1,tree e2,tsubst_flags_t complain)4918 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain)
4919 {
4920 tree t1 = non_reference (TREE_TYPE (e1));
4921 tree t2 = non_reference (TREE_TYPE (e2));
4922 conversion *conv;
4923 bool good_base;
4924
4925 /* [expr.cond]
4926
4927 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4928 implicitly converted (clause _conv_) to the type "lvalue reference to
4929 T2", subject to the constraint that in the conversion the
4930 reference must bind directly (_dcl.init.ref_) to an lvalue.
4931
4932 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
4933 implicitly converted to the type "rvalue reference to T2", subject to
4934 the constraint that the reference must bind directly. */
4935 if (glvalue_p (e2))
4936 {
4937 tree rtype = cp_build_reference_type (t2, !lvalue_p (e2));
4938 conv = implicit_conversion (rtype,
4939 t1,
4940 e1,
4941 /*c_cast_p=*/false,
4942 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND
4943 |LOOKUP_ONLYCONVERTING,
4944 complain);
4945 if (conv && !conv->bad_p)
4946 return conv;
4947 }
4948
4949 /* If E2 is a prvalue or if neither of the conversions above can be done
4950 and at least one of the operands has (possibly cv-qualified) class
4951 type: */
4952 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2))
4953 return NULL;
4954
4955 /* [expr.cond]
4956
4957 If E1 and E2 have class type, and the underlying class types are
4958 the same or one is a base class of the other: E1 can be converted
4959 to match E2 if the class of T2 is the same type as, or a base
4960 class of, the class of T1, and the cv-qualification of T2 is the
4961 same cv-qualification as, or a greater cv-qualification than, the
4962 cv-qualification of T1. If the conversion is applied, E1 is
4963 changed to an rvalue of type T2 that still refers to the original
4964 source class object (or the appropriate subobject thereof). */
4965 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4966 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4967 {
4968 if (good_base && at_least_as_qualified_p (t2, t1))
4969 {
4970 conv = build_identity_conv (t1, e1);
4971 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4972 TYPE_MAIN_VARIANT (t2)))
4973 conv = build_conv (ck_base, t2, conv);
4974 else
4975 conv = build_conv (ck_rvalue, t2, conv);
4976 return conv;
4977 }
4978 else
4979 return NULL;
4980 }
4981 else
4982 /* [expr.cond]
4983
4984 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4985 converted to the type that expression E2 would have if E2 were
4986 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4987 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4988 LOOKUP_IMPLICIT, complain);
4989 }
4990
4991 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4992 arguments to the conditional expression. */
4993
4994 static tree
build_conditional_expr_1(const op_location_t & loc,tree arg1,tree arg2,tree arg3,tsubst_flags_t complain)4995 build_conditional_expr_1 (const op_location_t &loc,
4996 tree arg1, tree arg2, tree arg3,
4997 tsubst_flags_t complain)
4998 {
4999 tree arg2_type;
5000 tree arg3_type;
5001 tree result = NULL_TREE;
5002 tree result_type = NULL_TREE;
5003 bool is_glvalue = true;
5004 struct z_candidate *candidates = 0;
5005 struct z_candidate *cand;
5006 void *p;
5007 tree orig_arg2, orig_arg3;
5008
5009 /* As a G++ extension, the second argument to the conditional can be
5010 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
5011 c'.) If the second operand is omitted, make sure it is
5012 calculated only once. */
5013 if (!arg2)
5014 {
5015 if (complain & tf_error)
5016 pedwarn (loc, OPT_Wpedantic,
5017 "ISO C++ forbids omitting the middle term of a ?: expression");
5018
5019 if ((complain & tf_warning) && !truth_value_p (TREE_CODE (arg1)))
5020 warn_for_omitted_condop (loc, arg1);
5021
5022 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
5023 if (lvalue_p (arg1))
5024 arg2 = arg1 = cp_stabilize_reference (arg1);
5025 else
5026 arg2 = arg1 = cp_save_expr (arg1);
5027 }
5028
5029 /* If something has already gone wrong, just pass that fact up the
5030 tree. */
5031 if (error_operand_p (arg1)
5032 || error_operand_p (arg2)
5033 || error_operand_p (arg3))
5034 return error_mark_node;
5035
5036 orig_arg2 = arg2;
5037 orig_arg3 = arg3;
5038
5039 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1)))
5040 {
5041 tree arg1_type = TREE_TYPE (arg1);
5042
5043 /* If arg1 is another cond_expr choosing between -1 and 0,
5044 then we can use its comparison. It may help to avoid
5045 additional comparison, produce more accurate diagnostics
5046 and enables folding. */
5047 if (TREE_CODE (arg1) == VEC_COND_EXPR
5048 && integer_minus_onep (TREE_OPERAND (arg1, 1))
5049 && integer_zerop (TREE_OPERAND (arg1, 2)))
5050 arg1 = TREE_OPERAND (arg1, 0);
5051
5052 arg1 = force_rvalue (arg1, complain);
5053 arg2 = force_rvalue (arg2, complain);
5054 arg3 = force_rvalue (arg3, complain);
5055
5056 /* force_rvalue can return error_mark on valid arguments. */
5057 if (error_operand_p (arg1)
5058 || error_operand_p (arg2)
5059 || error_operand_p (arg3))
5060 return error_mark_node;
5061
5062 arg2_type = TREE_TYPE (arg2);
5063 arg3_type = TREE_TYPE (arg3);
5064
5065 if (!VECTOR_TYPE_P (arg2_type)
5066 && !VECTOR_TYPE_P (arg3_type))
5067 {
5068 /* Rely on the error messages of the scalar version. */
5069 tree scal = build_conditional_expr_1 (loc, integer_one_node,
5070 orig_arg2, orig_arg3, complain);
5071 if (scal == error_mark_node)
5072 return error_mark_node;
5073 tree stype = TREE_TYPE (scal);
5074 tree ctype = TREE_TYPE (arg1_type);
5075 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype)
5076 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype)))
5077 {
5078 if (complain & tf_error)
5079 error_at (loc, "inferred scalar type %qT is not an integer or "
5080 "floating point type of the same size as %qT", stype,
5081 COMPARISON_CLASS_P (arg1)
5082 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0)))
5083 : ctype);
5084 return error_mark_node;
5085 }
5086
5087 tree vtype = build_opaque_vector_type (stype,
5088 TYPE_VECTOR_SUBPARTS (arg1_type));
5089 /* We could pass complain & tf_warning to unsafe_conversion_p,
5090 but the warnings (like Wsign-conversion) have already been
5091 given by the scalar build_conditional_expr_1. We still check
5092 unsafe_conversion_p to forbid truncating long long -> float. */
5093 if (unsafe_conversion_p (loc, stype, arg2, NULL_TREE, false))
5094 {
5095 if (complain & tf_error)
5096 error_at (loc, "conversion of scalar %qH to vector %qI "
5097 "involves truncation", arg2_type, vtype);
5098 return error_mark_node;
5099 }
5100 if (unsafe_conversion_p (loc, stype, arg3, NULL_TREE, false))
5101 {
5102 if (complain & tf_error)
5103 error_at (loc, "conversion of scalar %qH to vector %qI "
5104 "involves truncation", arg3_type, vtype);
5105 return error_mark_node;
5106 }
5107
5108 arg2 = cp_convert (stype, arg2, complain);
5109 arg2 = save_expr (arg2);
5110 arg2 = build_vector_from_val (vtype, arg2);
5111 arg2_type = vtype;
5112 arg3 = cp_convert (stype, arg3, complain);
5113 arg3 = save_expr (arg3);
5114 arg3 = build_vector_from_val (vtype, arg3);
5115 arg3_type = vtype;
5116 }
5117
5118 if (VECTOR_TYPE_P (arg2_type) != VECTOR_TYPE_P (arg3_type))
5119 {
5120 enum stv_conv convert_flag =
5121 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3,
5122 complain & tf_error);
5123
5124 switch (convert_flag)
5125 {
5126 case stv_error:
5127 return error_mark_node;
5128 case stv_firstarg:
5129 {
5130 arg2 = save_expr (arg2);
5131 arg2 = convert (TREE_TYPE (arg3_type), arg2);
5132 arg2 = build_vector_from_val (arg3_type, arg2);
5133 arg2_type = TREE_TYPE (arg2);
5134 break;
5135 }
5136 case stv_secondarg:
5137 {
5138 arg3 = save_expr (arg3);
5139 arg3 = convert (TREE_TYPE (arg2_type), arg3);
5140 arg3 = build_vector_from_val (arg2_type, arg3);
5141 arg3_type = TREE_TYPE (arg3);
5142 break;
5143 }
5144 default:
5145 break;
5146 }
5147 }
5148
5149 if (!same_type_p (arg2_type, arg3_type)
5150 || maybe_ne (TYPE_VECTOR_SUBPARTS (arg1_type),
5151 TYPE_VECTOR_SUBPARTS (arg2_type))
5152 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type))
5153 {
5154 if (complain & tf_error)
5155 error_at (loc,
5156 "incompatible vector types in conditional expression: "
5157 "%qT, %qT and %qT", TREE_TYPE (arg1),
5158 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3));
5159 return error_mark_node;
5160 }
5161
5162 if (!COMPARISON_CLASS_P (arg1))
5163 {
5164 tree cmp_type = build_same_sized_truth_vector_type (arg1_type);
5165 arg1 = build2 (NE_EXPR, cmp_type, arg1, build_zero_cst (arg1_type));
5166 }
5167 return build3_loc (loc, VEC_COND_EXPR, arg2_type, arg1, arg2, arg3);
5168 }
5169
5170 /* [expr.cond]
5171
5172 The first expression is implicitly converted to bool (clause
5173 _conv_). */
5174 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
5175 LOOKUP_NORMAL);
5176 if (error_operand_p (arg1))
5177 return error_mark_node;
5178
5179 /* [expr.cond]
5180
5181 If either the second or the third operand has type (possibly
5182 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
5183 array-to-pointer (_conv.array_), and function-to-pointer
5184 (_conv.func_) standard conversions are performed on the second
5185 and third operands. */
5186 arg2_type = unlowered_expr_type (arg2);
5187 arg3_type = unlowered_expr_type (arg3);
5188 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
5189 {
5190 /* Do the conversions. We don't these for `void' type arguments
5191 since it can't have any effect and since decay_conversion
5192 does not handle that case gracefully. */
5193 if (!VOID_TYPE_P (arg2_type))
5194 arg2 = decay_conversion (arg2, complain);
5195 if (!VOID_TYPE_P (arg3_type))
5196 arg3 = decay_conversion (arg3, complain);
5197 arg2_type = TREE_TYPE (arg2);
5198 arg3_type = TREE_TYPE (arg3);
5199
5200 /* [expr.cond]
5201
5202 One of the following shall hold:
5203
5204 --The second or the third operand (but not both) is a
5205 throw-expression (_except.throw_); the result is of the
5206 type of the other and is an rvalue.
5207
5208 --Both the second and the third operands have type void; the
5209 result is of type void and is an rvalue.
5210
5211 We must avoid calling force_rvalue for expressions of type
5212 "void" because it will complain that their value is being
5213 used. */
5214 if (TREE_CODE (arg2) == THROW_EXPR
5215 && TREE_CODE (arg3) != THROW_EXPR)
5216 {
5217 if (!VOID_TYPE_P (arg3_type))
5218 {
5219 arg3 = force_rvalue (arg3, complain);
5220 if (arg3 == error_mark_node)
5221 return error_mark_node;
5222 }
5223 arg3_type = TREE_TYPE (arg3);
5224 result_type = arg3_type;
5225 }
5226 else if (TREE_CODE (arg2) != THROW_EXPR
5227 && TREE_CODE (arg3) == THROW_EXPR)
5228 {
5229 if (!VOID_TYPE_P (arg2_type))
5230 {
5231 arg2 = force_rvalue (arg2, complain);
5232 if (arg2 == error_mark_node)
5233 return error_mark_node;
5234 }
5235 arg2_type = TREE_TYPE (arg2);
5236 result_type = arg2_type;
5237 }
5238 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
5239 result_type = void_type_node;
5240 else
5241 {
5242 if (complain & tf_error)
5243 {
5244 if (VOID_TYPE_P (arg2_type))
5245 error_at (cp_expr_loc_or_loc (arg3, loc),
5246 "second operand to the conditional operator "
5247 "is of type %<void%>, but the third operand is "
5248 "neither a throw-expression nor of type %<void%>");
5249 else
5250 error_at (cp_expr_loc_or_loc (arg2, loc),
5251 "third operand to the conditional operator "
5252 "is of type %<void%>, but the second operand is "
5253 "neither a throw-expression nor of type %<void%>");
5254 }
5255 return error_mark_node;
5256 }
5257
5258 is_glvalue = false;
5259 goto valid_operands;
5260 }
5261 /* [expr.cond]
5262
5263 Otherwise, if the second and third operand have different types,
5264 and either has (possibly cv-qualified) class type, or if both are
5265 glvalues of the same value category and the same type except for
5266 cv-qualification, an attempt is made to convert each of those operands
5267 to the type of the other. */
5268 else if (!same_type_p (arg2_type, arg3_type)
5269 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)
5270 || (same_type_ignoring_top_level_qualifiers_p (arg2_type,
5271 arg3_type)
5272 && glvalue_p (arg2) && glvalue_p (arg3)
5273 && lvalue_p (arg2) == lvalue_p (arg3))))
5274 {
5275 conversion *conv2;
5276 conversion *conv3;
5277 bool converted = false;
5278
5279 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5280 p = conversion_obstack_alloc (0);
5281
5282 conv2 = conditional_conversion (arg2, arg3, complain);
5283 conv3 = conditional_conversion (arg3, arg2, complain);
5284
5285 /* [expr.cond]
5286
5287 If both can be converted, or one can be converted but the
5288 conversion is ambiguous, the program is ill-formed. If
5289 neither can be converted, the operands are left unchanged and
5290 further checking is performed as described below. If exactly
5291 one conversion is possible, that conversion is applied to the
5292 chosen operand and the converted operand is used in place of
5293 the original operand for the remainder of this section. */
5294 if ((conv2 && !conv2->bad_p
5295 && conv3 && !conv3->bad_p)
5296 || (conv2 && conv2->kind == ck_ambig)
5297 || (conv3 && conv3->kind == ck_ambig))
5298 {
5299 if (complain & tf_error)
5300 {
5301 error_at (loc, "operands to ?: have different types %qT and %qT",
5302 arg2_type, arg3_type);
5303 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p)
5304 inform (loc, " and each type can be converted to the other");
5305 else if (conv2 && conv2->kind == ck_ambig)
5306 convert_like (conv2, arg2, complain);
5307 else
5308 convert_like (conv3, arg3, complain);
5309 }
5310 result = error_mark_node;
5311 }
5312 else if (conv2 && !conv2->bad_p)
5313 {
5314 arg2 = convert_like (conv2, arg2, complain);
5315 arg2 = convert_from_reference (arg2);
5316 arg2_type = TREE_TYPE (arg2);
5317 /* Even if CONV2 is a valid conversion, the result of the
5318 conversion may be invalid. For example, if ARG3 has type
5319 "volatile X", and X does not have a copy constructor
5320 accepting a "volatile X&", then even if ARG2 can be
5321 converted to X, the conversion will fail. */
5322 if (error_operand_p (arg2))
5323 result = error_mark_node;
5324 converted = true;
5325 }
5326 else if (conv3 && !conv3->bad_p)
5327 {
5328 arg3 = convert_like (conv3, arg3, complain);
5329 arg3 = convert_from_reference (arg3);
5330 arg3_type = TREE_TYPE (arg3);
5331 if (error_operand_p (arg3))
5332 result = error_mark_node;
5333 converted = true;
5334 }
5335
5336 /* Free all the conversions we allocated. */
5337 obstack_free (&conversion_obstack, p);
5338
5339 if (result)
5340 return result;
5341
5342 /* If, after the conversion, both operands have class type,
5343 treat the cv-qualification of both operands as if it were the
5344 union of the cv-qualification of the operands.
5345
5346 The standard is not clear about what to do in this
5347 circumstance. For example, if the first operand has type
5348 "const X" and the second operand has a user-defined
5349 conversion to "volatile X", what is the type of the second
5350 operand after this step? Making it be "const X" (matching
5351 the first operand) seems wrong, as that discards the
5352 qualification without actually performing a copy. Leaving it
5353 as "volatile X" seems wrong as that will result in the
5354 conditional expression failing altogether, even though,
5355 according to this step, the one operand could be converted to
5356 the type of the other. */
5357 if (converted
5358 && CLASS_TYPE_P (arg2_type)
5359 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
5360 arg2_type = arg3_type =
5361 cp_build_qualified_type (arg2_type,
5362 cp_type_quals (arg2_type)
5363 | cp_type_quals (arg3_type));
5364 }
5365
5366 /* [expr.cond]
5367
5368 If the second and third operands are glvalues of the same value
5369 category and have the same type, the result is of that type and
5370 value category. */
5371 if (((lvalue_p (arg2) && lvalue_p (arg3))
5372 || (xvalue_p (arg2) && xvalue_p (arg3)))
5373 && same_type_p (arg2_type, arg3_type))
5374 {
5375 result_type = arg2_type;
5376 if (processing_template_decl)
5377 /* Let lvalue_kind know this was a glvalue. */
5378 result_type = cp_build_reference_type (result_type, xvalue_p (arg2));
5379
5380 arg2 = mark_lvalue_use (arg2);
5381 arg3 = mark_lvalue_use (arg3);
5382 goto valid_operands;
5383 }
5384
5385 /* [expr.cond]
5386
5387 Otherwise, the result is an rvalue. If the second and third
5388 operand do not have the same type, and either has (possibly
5389 cv-qualified) class type, overload resolution is used to
5390 determine the conversions (if any) to be applied to the operands
5391 (_over.match.oper_, _over.built_). */
5392 is_glvalue = false;
5393 if (!same_type_p (arg2_type, arg3_type)
5394 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
5395 {
5396 tree args[3];
5397 conversion *conv;
5398 bool any_viable_p;
5399
5400 /* Rearrange the arguments so that add_builtin_candidate only has
5401 to know about two args. In build_builtin_candidate, the
5402 arguments are unscrambled. */
5403 args[0] = arg2;
5404 args[1] = arg3;
5405 args[2] = arg1;
5406 add_builtin_candidates (&candidates,
5407 COND_EXPR,
5408 NOP_EXPR,
5409 ovl_op_identifier (false, COND_EXPR),
5410 args,
5411 LOOKUP_NORMAL, complain);
5412
5413 /* [expr.cond]
5414
5415 If the overload resolution fails, the program is
5416 ill-formed. */
5417 candidates = splice_viable (candidates, false, &any_viable_p);
5418 if (!any_viable_p)
5419 {
5420 if (complain & tf_error)
5421 error_at (loc, "operands to ?: have different types %qT and %qT",
5422 arg2_type, arg3_type);
5423 return error_mark_node;
5424 }
5425 cand = tourney (candidates, complain);
5426 if (!cand)
5427 {
5428 if (complain & tf_error)
5429 {
5430 auto_diagnostic_group d;
5431 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
5432 print_z_candidates (loc, candidates);
5433 }
5434 return error_mark_node;
5435 }
5436
5437 /* [expr.cond]
5438
5439 Otherwise, the conversions thus determined are applied, and
5440 the converted operands are used in place of the original
5441 operands for the remainder of this section. */
5442 conv = cand->convs[0];
5443 arg1 = convert_like (conv, arg1, complain);
5444 conv = cand->convs[1];
5445 arg2 = convert_like (conv, arg2, complain);
5446 arg2_type = TREE_TYPE (arg2);
5447 conv = cand->convs[2];
5448 arg3 = convert_like (conv, arg3, complain);
5449 arg3_type = TREE_TYPE (arg3);
5450 }
5451
5452 /* [expr.cond]
5453
5454 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
5455 and function-to-pointer (_conv.func_) standard conversions are
5456 performed on the second and third operands.
5457
5458 We need to force the lvalue-to-rvalue conversion here for class types,
5459 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
5460 that isn't wrapped with a TARGET_EXPR plays havoc with exception
5461 regions. */
5462
5463 arg2 = force_rvalue (arg2, complain);
5464 if (!CLASS_TYPE_P (arg2_type))
5465 arg2_type = TREE_TYPE (arg2);
5466
5467 arg3 = force_rvalue (arg3, complain);
5468 if (!CLASS_TYPE_P (arg3_type))
5469 arg3_type = TREE_TYPE (arg3);
5470
5471 if (arg2 == error_mark_node || arg3 == error_mark_node)
5472 return error_mark_node;
5473
5474 /* [expr.cond]
5475
5476 After those conversions, one of the following shall hold:
5477
5478 --The second and third operands have the same type; the result is of
5479 that type. */
5480 if (same_type_p (arg2_type, arg3_type))
5481 result_type = arg2_type;
5482 /* [expr.cond]
5483
5484 --The second and third operands have arithmetic or enumeration
5485 type; the usual arithmetic conversions are performed to bring
5486 them to a common type, and the result is of that type. */
5487 else if ((ARITHMETIC_TYPE_P (arg2_type)
5488 || UNSCOPED_ENUM_P (arg2_type))
5489 && (ARITHMETIC_TYPE_P (arg3_type)
5490 || UNSCOPED_ENUM_P (arg3_type)))
5491 {
5492 /* In this case, there is always a common type. */
5493 result_type = type_after_usual_arithmetic_conversions (arg2_type,
5494 arg3_type);
5495 if (complain & tf_warning)
5496 do_warn_double_promotion (result_type, arg2_type, arg3_type,
5497 "implicit conversion from %qH to %qI to "
5498 "match other result of conditional",
5499 loc);
5500
5501 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
5502 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
5503 {
5504 tree stripped_orig_arg2 = tree_strip_any_location_wrapper (orig_arg2);
5505 tree stripped_orig_arg3 = tree_strip_any_location_wrapper (orig_arg3);
5506 if (TREE_CODE (stripped_orig_arg2) == CONST_DECL
5507 && TREE_CODE (stripped_orig_arg3) == CONST_DECL
5508 && (DECL_CONTEXT (stripped_orig_arg2)
5509 == DECL_CONTEXT (stripped_orig_arg3)))
5510 /* Two enumerators from the same enumeration can have different
5511 types when the enumeration is still being defined. */;
5512 else if (complain & tf_warning)
5513 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in "
5514 "conditional expression: %qT vs %qT",
5515 arg2_type, arg3_type);
5516 }
5517 else if (extra_warnings
5518 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
5519 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
5520 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
5521 && !same_type_p (arg2_type,
5522 type_promotes_to (arg3_type)))))
5523 {
5524 if (complain & tf_warning)
5525 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in "
5526 "conditional expression");
5527 }
5528
5529 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5530 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5531 }
5532 /* [expr.cond]
5533
5534 --The second and third operands have pointer type, or one has
5535 pointer type and the other is a null pointer constant; pointer
5536 conversions (_conv.ptr_) and qualification conversions
5537 (_conv.qual_) are performed to bring them to their composite
5538 pointer type (_expr.rel_). The result is of the composite
5539 pointer type.
5540
5541 --The second and third operands have pointer to member type, or
5542 one has pointer to member type and the other is a null pointer
5543 constant; pointer to member conversions (_conv.mem_) and
5544 qualification conversions (_conv.qual_) are performed to bring
5545 them to a common type, whose cv-qualification shall match the
5546 cv-qualification of either the second or the third operand.
5547 The result is of the common type. */
5548 else if ((null_ptr_cst_p (arg2)
5549 && TYPE_PTR_OR_PTRMEM_P (arg3_type))
5550 || (null_ptr_cst_p (arg3)
5551 && TYPE_PTR_OR_PTRMEM_P (arg2_type))
5552 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
5553 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type))
5554 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
5555 {
5556 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
5557 arg3, CPO_CONDITIONAL_EXPR,
5558 complain);
5559 if (result_type == error_mark_node)
5560 return error_mark_node;
5561 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5562 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5563 }
5564
5565 if (!result_type)
5566 {
5567 if (complain & tf_error)
5568 error_at (loc, "operands to ?: have different types %qT and %qT",
5569 arg2_type, arg3_type);
5570 return error_mark_node;
5571 }
5572
5573 if (arg2 == error_mark_node || arg3 == error_mark_node)
5574 return error_mark_node;
5575
5576 valid_operands:
5577 result = build3_loc (loc, COND_EXPR, result_type, arg1, arg2, arg3);
5578
5579 /* If the ARG2 and ARG3 are the same and don't have side-effects,
5580 warn here, because the COND_EXPR will be turned into ARG2. */
5581 if (warn_duplicated_branches
5582 && (complain & tf_warning)
5583 && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0)))
5584 warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches,
5585 "this condition has identical branches");
5586
5587 /* We can't use result_type below, as fold might have returned a
5588 throw_expr. */
5589
5590 if (!is_glvalue)
5591 {
5592 /* Expand both sides into the same slot, hopefully the target of
5593 the ?: expression. We used to check for TARGET_EXPRs here,
5594 but now we sometimes wrap them in NOP_EXPRs so the test would
5595 fail. */
5596 if (CLASS_TYPE_P (TREE_TYPE (result)))
5597 result = get_target_expr_sfinae (result, complain);
5598 /* If this expression is an rvalue, but might be mistaken for an
5599 lvalue, we must add a NON_LVALUE_EXPR. */
5600 result = rvalue (result);
5601 }
5602 else
5603 result = force_paren_expr (result);
5604
5605 return result;
5606 }
5607
5608 /* Wrapper for above. */
5609
5610 tree
build_conditional_expr(const op_location_t & loc,tree arg1,tree arg2,tree arg3,tsubst_flags_t complain)5611 build_conditional_expr (const op_location_t &loc,
5612 tree arg1, tree arg2, tree arg3,
5613 tsubst_flags_t complain)
5614 {
5615 tree ret;
5616 bool subtime = timevar_cond_start (TV_OVERLOAD);
5617 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain);
5618 timevar_cond_stop (TV_OVERLOAD, subtime);
5619 return ret;
5620 }
5621
5622 /* OPERAND is an operand to an expression. Perform necessary steps
5623 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
5624 returned. */
5625
5626 static tree
prep_operand(tree operand)5627 prep_operand (tree operand)
5628 {
5629 if (operand)
5630 {
5631 if (CLASS_TYPE_P (TREE_TYPE (operand))
5632 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
5633 /* Make sure the template type is instantiated now. */
5634 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
5635 }
5636
5637 return operand;
5638 }
5639
5640 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
5641 OVERLOAD) to the CANDIDATES, returning an updated list of
5642 CANDIDATES. The ARGS are the arguments provided to the call;
5643 if FIRST_ARG is non-null it is the implicit object argument,
5644 otherwise the first element of ARGS is used if needed. The
5645 EXPLICIT_TARGS are explicit template arguments provided.
5646 TEMPLATE_ONLY is true if only template functions should be
5647 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
5648 add_function_candidate. */
5649
5650 static void
add_candidates(tree fns,tree first_arg,const vec<tree,va_gc> * args,tree return_type,tree explicit_targs,bool template_only,tree conversion_path,tree access_path,int flags,struct z_candidate ** candidates,tsubst_flags_t complain)5651 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args,
5652 tree return_type,
5653 tree explicit_targs, bool template_only,
5654 tree conversion_path, tree access_path,
5655 int flags,
5656 struct z_candidate **candidates,
5657 tsubst_flags_t complain)
5658 {
5659 tree ctype;
5660 const vec<tree, va_gc> *non_static_args;
5661 bool check_list_ctor = false;
5662 bool check_converting = false;
5663 unification_kind_t strict;
5664
5665 if (!fns)
5666 return;
5667
5668 /* Precalculate special handling of constructors and conversion ops. */
5669 tree fn = OVL_FIRST (fns);
5670 if (DECL_CONV_FN_P (fn))
5671 {
5672 check_list_ctor = false;
5673 check_converting = (flags & LOOKUP_ONLYCONVERTING) != 0;
5674 if (flags & LOOKUP_NO_CONVERSION)
5675 /* We're doing return_type(x). */
5676 strict = DEDUCE_CONV;
5677 else
5678 /* We're doing x.operator return_type(). */
5679 strict = DEDUCE_EXACT;
5680 /* [over.match.funcs] For conversion functions, the function
5681 is considered to be a member of the class of the implicit
5682 object argument for the purpose of defining the type of
5683 the implicit object parameter. */
5684 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg));
5685 }
5686 else
5687 {
5688 if (DECL_CONSTRUCTOR_P (fn))
5689 {
5690 check_list_ctor = (flags & LOOKUP_LIST_ONLY) != 0;
5691 /* For list-initialization we consider explicit constructors
5692 and complain if one is chosen. */
5693 check_converting
5694 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR))
5695 == LOOKUP_ONLYCONVERTING);
5696 }
5697 strict = DEDUCE_CALL;
5698 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
5699 }
5700
5701 if (first_arg)
5702 non_static_args = args;
5703 else
5704 /* Delay creating the implicit this parameter until it is needed. */
5705 non_static_args = NULL;
5706
5707 for (lkp_iterator iter (fns); iter; ++iter)
5708 {
5709 fn = *iter;
5710
5711 if (check_converting && DECL_NONCONVERTING_P (fn))
5712 continue;
5713 if (check_list_ctor && !is_list_ctor (fn))
5714 continue;
5715
5716 tree fn_first_arg = NULL_TREE;
5717 const vec<tree, va_gc> *fn_args = args;
5718
5719 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
5720 {
5721 /* Figure out where the object arg comes from. If this
5722 function is a non-static member and we didn't get an
5723 implicit object argument, move it out of args. */
5724 if (first_arg == NULL_TREE)
5725 {
5726 unsigned int ix;
5727 tree arg;
5728 vec<tree, va_gc> *tempvec;
5729 vec_alloc (tempvec, args->length () - 1);
5730 for (ix = 1; args->iterate (ix, &arg); ++ix)
5731 tempvec->quick_push (arg);
5732 non_static_args = tempvec;
5733 first_arg = (*args)[0];
5734 }
5735
5736 fn_first_arg = first_arg;
5737 fn_args = non_static_args;
5738 }
5739
5740 if (TREE_CODE (fn) == TEMPLATE_DECL)
5741 add_template_candidate (candidates,
5742 fn,
5743 ctype,
5744 explicit_targs,
5745 fn_first_arg,
5746 fn_args,
5747 return_type,
5748 access_path,
5749 conversion_path,
5750 flags,
5751 strict,
5752 complain);
5753 else if (!template_only)
5754 add_function_candidate (candidates,
5755 fn,
5756 ctype,
5757 fn_first_arg,
5758 fn_args,
5759 access_path,
5760 conversion_path,
5761 flags,
5762 NULL,
5763 complain);
5764 }
5765 }
5766
5767 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first,
5768 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */
5769
5770 static int
op_is_ordered(tree_code code)5771 op_is_ordered (tree_code code)
5772 {
5773 switch (code)
5774 {
5775 // 5. b @= a
5776 case MODIFY_EXPR:
5777 return (flag_strong_eval_order > 1 ? -1 : 0);
5778
5779 // 6. a[b]
5780 case ARRAY_REF:
5781 return (flag_strong_eval_order > 1 ? 1 : 0);
5782
5783 // 1. a.b
5784 // Not overloadable (yet).
5785 // 2. a->b
5786 // Only one argument.
5787 // 3. a->*b
5788 case MEMBER_REF:
5789 // 7. a << b
5790 case LSHIFT_EXPR:
5791 // 8. a >> b
5792 case RSHIFT_EXPR:
5793 // a && b
5794 // Predates P0145R3.
5795 case TRUTH_ANDIF_EXPR:
5796 // a || b
5797 // Predates P0145R3.
5798 case TRUTH_ORIF_EXPR:
5799 // a , b
5800 // Predates P0145R3.
5801 case COMPOUND_EXPR:
5802 return (flag_strong_eval_order ? 1 : 0);
5803
5804 default:
5805 return 0;
5806 }
5807 }
5808
5809 static tree
build_new_op_1(const op_location_t & loc,enum tree_code code,int flags,tree arg1,tree arg2,tree arg3,tree * overload,tsubst_flags_t complain)5810 build_new_op_1 (const op_location_t &loc, enum tree_code code, int flags,
5811 tree arg1, tree arg2, tree arg3, tree *overload,
5812 tsubst_flags_t complain)
5813 {
5814 struct z_candidate *candidates = 0, *cand;
5815 vec<tree, va_gc> *arglist;
5816 tree args[3];
5817 tree result = NULL_TREE;
5818 bool result_valid_p = false;
5819 enum tree_code code2 = NOP_EXPR;
5820 enum tree_code code_orig_arg1 = ERROR_MARK;
5821 enum tree_code code_orig_arg2 = ERROR_MARK;
5822 conversion *conv;
5823 void *p;
5824 bool strict_p;
5825 bool any_viable_p;
5826
5827 if (error_operand_p (arg1)
5828 || error_operand_p (arg2)
5829 || error_operand_p (arg3))
5830 return error_mark_node;
5831
5832 bool ismodop = code == MODIFY_EXPR;
5833 if (ismodop)
5834 {
5835 code2 = TREE_CODE (arg3);
5836 arg3 = NULL_TREE;
5837 }
5838 tree fnname = ovl_op_identifier (ismodop, ismodop ? code2 : code);
5839
5840 arg1 = prep_operand (arg1);
5841
5842 bool memonly = false;
5843 switch (code)
5844 {
5845 case NEW_EXPR:
5846 case VEC_NEW_EXPR:
5847 case VEC_DELETE_EXPR:
5848 case DELETE_EXPR:
5849 /* Use build_op_new_call and build_op_delete_call instead. */
5850 gcc_unreachable ();
5851
5852 case CALL_EXPR:
5853 /* Use build_op_call instead. */
5854 gcc_unreachable ();
5855
5856 case TRUTH_ORIF_EXPR:
5857 case TRUTH_ANDIF_EXPR:
5858 case TRUTH_AND_EXPR:
5859 case TRUTH_OR_EXPR:
5860 /* These are saved for the sake of warn_logical_operator. */
5861 code_orig_arg1 = TREE_CODE (arg1);
5862 code_orig_arg2 = TREE_CODE (arg2);
5863 break;
5864 case GT_EXPR:
5865 case LT_EXPR:
5866 case GE_EXPR:
5867 case LE_EXPR:
5868 case EQ_EXPR:
5869 case NE_EXPR:
5870 /* These are saved for the sake of maybe_warn_bool_compare. */
5871 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1));
5872 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2));
5873 break;
5874
5875 /* =, ->, [], () must be non-static member functions. */
5876 case MODIFY_EXPR:
5877 if (code2 != NOP_EXPR)
5878 break;
5879 /* FALLTHRU */
5880 case COMPONENT_REF:
5881 case ARRAY_REF:
5882 memonly = true;
5883 break;
5884
5885 default:
5886 break;
5887 }
5888
5889 arg2 = prep_operand (arg2);
5890 arg3 = prep_operand (arg3);
5891
5892 if (code == COND_EXPR)
5893 /* Use build_conditional_expr instead. */
5894 gcc_unreachable ();
5895 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1))
5896 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2))))
5897 goto builtin;
5898
5899 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
5900 arg2 = integer_zero_node;
5901
5902 vec_alloc (arglist, 3);
5903 arglist->quick_push (arg1);
5904 if (arg2 != NULL_TREE)
5905 arglist->quick_push (arg2);
5906 if (arg3 != NULL_TREE)
5907 arglist->quick_push (arg3);
5908
5909 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5910 p = conversion_obstack_alloc (0);
5911
5912 /* Add namespace-scope operators to the list of functions to
5913 consider. */
5914 if (!memonly)
5915 {
5916 tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0);
5917 fns = lookup_arg_dependent (fnname, fns, arglist);
5918 add_candidates (fns, NULL_TREE, arglist, NULL_TREE,
5919 NULL_TREE, false, NULL_TREE, NULL_TREE,
5920 flags, &candidates, complain);
5921 }
5922
5923 args[0] = arg1;
5924 args[1] = arg2;
5925 args[2] = NULL_TREE;
5926
5927 /* Add class-member operators to the candidate set. */
5928 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
5929 {
5930 tree fns;
5931
5932 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
5933 if (fns == error_mark_node)
5934 {
5935 result = error_mark_node;
5936 goto user_defined_result_ready;
5937 }
5938 if (fns)
5939 add_candidates (BASELINK_FUNCTIONS (fns),
5940 NULL_TREE, arglist, NULL_TREE,
5941 NULL_TREE, false,
5942 BASELINK_BINFO (fns),
5943 BASELINK_ACCESS_BINFO (fns),
5944 flags, &candidates, complain);
5945 }
5946 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then
5947 only non-member functions that have type T1 or reference to
5948 cv-qualified-opt T1 for the first argument, if the first argument
5949 has an enumeration type, or T2 or reference to cv-qualified-opt
5950 T2 for the second argument, if the second argument has an
5951 enumeration type. Filter out those that don't match. */
5952 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2)))
5953 {
5954 struct z_candidate **candp, **next;
5955
5956 for (candp = &candidates; *candp; candp = next)
5957 {
5958 tree parmlist, parmtype;
5959 int i, nargs = (arg2 ? 2 : 1);
5960
5961 cand = *candp;
5962 next = &cand->next;
5963
5964 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
5965
5966 for (i = 0; i < nargs; ++i)
5967 {
5968 parmtype = TREE_VALUE (parmlist);
5969
5970 if (TYPE_REF_P (parmtype))
5971 parmtype = TREE_TYPE (parmtype);
5972 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE
5973 && (same_type_ignoring_top_level_qualifiers_p
5974 (TREE_TYPE (args[i]), parmtype)))
5975 break;
5976
5977 parmlist = TREE_CHAIN (parmlist);
5978 }
5979
5980 /* No argument has an appropriate type, so remove this
5981 candidate function from the list. */
5982 if (i == nargs)
5983 {
5984 *candp = cand->next;
5985 next = candp;
5986 }
5987 }
5988 }
5989
5990 add_builtin_candidates (&candidates, code, code2, fnname, args,
5991 flags, complain);
5992
5993 switch (code)
5994 {
5995 case COMPOUND_EXPR:
5996 case ADDR_EXPR:
5997 /* For these, the built-in candidates set is empty
5998 [over.match.oper]/3. We don't want non-strict matches
5999 because exact matches are always possible with built-in
6000 operators. The built-in candidate set for COMPONENT_REF
6001 would be empty too, but since there are no such built-in
6002 operators, we accept non-strict matches for them. */
6003 strict_p = true;
6004 break;
6005
6006 default:
6007 strict_p = false;
6008 break;
6009 }
6010
6011 candidates = splice_viable (candidates, strict_p, &any_viable_p);
6012 if (!any_viable_p)
6013 {
6014 switch (code)
6015 {
6016 case POSTINCREMENT_EXPR:
6017 case POSTDECREMENT_EXPR:
6018 /* Don't try anything fancy if we're not allowed to produce
6019 errors. */
6020 if (!(complain & tf_error))
6021 return error_mark_node;
6022
6023 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
6024 distinguish between prefix and postfix ++ and
6025 operator++() was used for both, so we allow this with
6026 -fpermissive. */
6027 else
6028 {
6029 const char *msg = (flag_permissive)
6030 ? G_("no %<%D(int)%> declared for postfix %qs,"
6031 " trying prefix operator instead")
6032 : G_("no %<%D(int)%> declared for postfix %qs");
6033 permerror (loc, msg, fnname, OVL_OP_INFO (false, code)->name);
6034 }
6035
6036 if (!flag_permissive)
6037 return error_mark_node;
6038
6039 if (code == POSTINCREMENT_EXPR)
6040 code = PREINCREMENT_EXPR;
6041 else
6042 code = PREDECREMENT_EXPR;
6043 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE,
6044 NULL_TREE, overload, complain);
6045 break;
6046
6047 /* The caller will deal with these. */
6048 case ADDR_EXPR:
6049 case COMPOUND_EXPR:
6050 case COMPONENT_REF:
6051 result = NULL_TREE;
6052 result_valid_p = true;
6053 break;
6054
6055 default:
6056 if (complain & tf_error)
6057 {
6058 /* If one of the arguments of the operator represents
6059 an invalid use of member function pointer, try to report
6060 a meaningful error ... */
6061 if (invalid_nonstatic_memfn_p (loc, arg1, tf_error)
6062 || invalid_nonstatic_memfn_p (loc, arg2, tf_error)
6063 || invalid_nonstatic_memfn_p (loc, arg3, tf_error))
6064 /* We displayed the error message. */;
6065 else
6066 {
6067 /* ... Otherwise, report the more generic
6068 "no matching operator found" error */
6069 auto_diagnostic_group d;
6070 op_error (loc, code, code2, arg1, arg2, arg3, FALSE);
6071 print_z_candidates (loc, candidates);
6072 }
6073 }
6074 result = error_mark_node;
6075 break;
6076 }
6077 }
6078 else
6079 {
6080 cand = tourney (candidates, complain);
6081 if (cand == 0)
6082 {
6083 if (complain & tf_error)
6084 {
6085 auto_diagnostic_group d;
6086 op_error (loc, code, code2, arg1, arg2, arg3, TRUE);
6087 print_z_candidates (loc, candidates);
6088 }
6089 result = error_mark_node;
6090 }
6091 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
6092 {
6093 if (overload)
6094 *overload = cand->fn;
6095
6096 if (resolve_args (arglist, complain) == NULL)
6097 result = error_mark_node;
6098 else
6099 result = build_over_call (cand, LOOKUP_NORMAL, complain);
6100
6101 if (trivial_fn_p (cand->fn))
6102 /* There won't be a CALL_EXPR. */;
6103 else if (result && result != error_mark_node)
6104 {
6105 tree call = extract_call_expr (result);
6106 CALL_EXPR_OPERATOR_SYNTAX (call) = true;
6107
6108 if (processing_template_decl && DECL_HIDDEN_FRIEND_P (cand->fn))
6109 /* This prevents build_new_function_call from discarding this
6110 function during instantiation of the enclosing template. */
6111 KOENIG_LOOKUP_P (call) = 1;
6112
6113 /* Specify evaluation order as per P0145R2. */
6114 CALL_EXPR_ORDERED_ARGS (call) = false;
6115 switch (op_is_ordered (code))
6116 {
6117 case -1:
6118 CALL_EXPR_REVERSE_ARGS (call) = true;
6119 break;
6120
6121 case 1:
6122 CALL_EXPR_ORDERED_ARGS (call) = true;
6123 break;
6124
6125 default:
6126 break;
6127 }
6128 }
6129 }
6130 else
6131 {
6132 /* Give any warnings we noticed during overload resolution. */
6133 if (cand->warnings && (complain & tf_warning))
6134 {
6135 struct candidate_warning *w;
6136 for (w = cand->warnings; w; w = w->next)
6137 joust (cand, w->loser, 1, complain);
6138 }
6139
6140 /* Check for comparison of different enum types. */
6141 switch (code)
6142 {
6143 case GT_EXPR:
6144 case LT_EXPR:
6145 case GE_EXPR:
6146 case LE_EXPR:
6147 case EQ_EXPR:
6148 case NE_EXPR:
6149 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
6150 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
6151 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
6152 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
6153 && (complain & tf_warning))
6154 {
6155 warning (OPT_Wenum_compare,
6156 "comparison between %q#T and %q#T",
6157 TREE_TYPE (arg1), TREE_TYPE (arg2));
6158 }
6159 break;
6160 default:
6161 break;
6162 }
6163
6164 /* We need to strip any leading REF_BIND so that bitfields
6165 don't cause errors. This should not remove any important
6166 conversions, because builtins don't apply to class
6167 objects directly. */
6168 conv = cand->convs[0];
6169 if (conv->kind == ck_ref_bind)
6170 conv = next_conversion (conv);
6171 arg1 = convert_like (conv, arg1, complain);
6172
6173 if (arg2)
6174 {
6175 conv = cand->convs[1];
6176 if (conv->kind == ck_ref_bind)
6177 conv = next_conversion (conv);
6178 else
6179 arg2 = decay_conversion (arg2, complain);
6180
6181 /* We need to call warn_logical_operator before
6182 converting arg2 to a boolean_type, but after
6183 decaying an enumerator to its value. */
6184 if (complain & tf_warning)
6185 warn_logical_operator (loc, code, boolean_type_node,
6186 code_orig_arg1, arg1,
6187 code_orig_arg2, arg2);
6188
6189 arg2 = convert_like (conv, arg2, complain);
6190 }
6191 if (arg3)
6192 {
6193 conv = cand->convs[2];
6194 if (conv->kind == ck_ref_bind)
6195 conv = next_conversion (conv);
6196 arg3 = convert_like (conv, arg3, complain);
6197 }
6198
6199 }
6200 }
6201
6202 user_defined_result_ready:
6203
6204 /* Free all the conversions we allocated. */
6205 obstack_free (&conversion_obstack, p);
6206
6207 if (result || result_valid_p)
6208 return result;
6209
6210 builtin:
6211 switch (code)
6212 {
6213 case MODIFY_EXPR:
6214 return cp_build_modify_expr (loc, arg1, code2, arg2, complain);
6215
6216 case INDIRECT_REF:
6217 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
6218
6219 case TRUTH_ANDIF_EXPR:
6220 case TRUTH_ORIF_EXPR:
6221 case TRUTH_AND_EXPR:
6222 case TRUTH_OR_EXPR:
6223 if (complain & tf_warning)
6224 warn_logical_operator (loc, code, boolean_type_node,
6225 code_orig_arg1, arg1,
6226 code_orig_arg2, arg2);
6227 /* Fall through. */
6228 case GT_EXPR:
6229 case LT_EXPR:
6230 case GE_EXPR:
6231 case LE_EXPR:
6232 case EQ_EXPR:
6233 case NE_EXPR:
6234 if ((complain & tf_warning)
6235 && ((code_orig_arg1 == BOOLEAN_TYPE)
6236 ^ (code_orig_arg2 == BOOLEAN_TYPE)))
6237 maybe_warn_bool_compare (loc, code, arg1, arg2);
6238 if (complain & tf_warning && warn_tautological_compare)
6239 warn_tautological_cmp (loc, code, arg1, arg2);
6240 /* Fall through. */
6241 case PLUS_EXPR:
6242 case MINUS_EXPR:
6243 case MULT_EXPR:
6244 case TRUNC_DIV_EXPR:
6245 case MAX_EXPR:
6246 case MIN_EXPR:
6247 case LSHIFT_EXPR:
6248 case RSHIFT_EXPR:
6249 case TRUNC_MOD_EXPR:
6250 case BIT_AND_EXPR:
6251 case BIT_IOR_EXPR:
6252 case BIT_XOR_EXPR:
6253 return cp_build_binary_op (loc, code, arg1, arg2, complain);
6254
6255 case UNARY_PLUS_EXPR:
6256 case NEGATE_EXPR:
6257 case BIT_NOT_EXPR:
6258 case TRUTH_NOT_EXPR:
6259 case PREINCREMENT_EXPR:
6260 case POSTINCREMENT_EXPR:
6261 case PREDECREMENT_EXPR:
6262 case POSTDECREMENT_EXPR:
6263 case REALPART_EXPR:
6264 case IMAGPART_EXPR:
6265 case ABS_EXPR:
6266 return cp_build_unary_op (code, arg1, candidates != 0, complain);
6267
6268 case ARRAY_REF:
6269 return cp_build_array_ref (input_location, arg1, arg2, complain);
6270
6271 case MEMBER_REF:
6272 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR,
6273 complain),
6274 arg2, complain);
6275
6276 /* The caller will deal with these. */
6277 case ADDR_EXPR:
6278 case COMPONENT_REF:
6279 case COMPOUND_EXPR:
6280 return NULL_TREE;
6281
6282 default:
6283 gcc_unreachable ();
6284 }
6285 return NULL_TREE;
6286 }
6287
6288 /* Wrapper for above. */
6289
6290 tree
build_new_op(const op_location_t & loc,enum tree_code code,int flags,tree arg1,tree arg2,tree arg3,tree * overload,tsubst_flags_t complain)6291 build_new_op (const op_location_t &loc, enum tree_code code, int flags,
6292 tree arg1, tree arg2, tree arg3,
6293 tree *overload, tsubst_flags_t complain)
6294 {
6295 tree ret;
6296 bool subtime = timevar_cond_start (TV_OVERLOAD);
6297 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3,
6298 overload, complain);
6299 timevar_cond_stop (TV_OVERLOAD, subtime);
6300 return ret;
6301 }
6302
6303 /* CALL was returned by some call-building function; extract the actual
6304 CALL_EXPR from any bits that have been tacked on, e.g. by
6305 convert_from_reference. */
6306
6307 tree
extract_call_expr(tree call)6308 extract_call_expr (tree call)
6309 {
6310 while (TREE_CODE (call) == COMPOUND_EXPR)
6311 call = TREE_OPERAND (call, 1);
6312 if (REFERENCE_REF_P (call))
6313 call = TREE_OPERAND (call, 0);
6314 if (TREE_CODE (call) == TARGET_EXPR)
6315 call = TARGET_EXPR_INITIAL (call);
6316 gcc_assert (TREE_CODE (call) == CALL_EXPR
6317 || TREE_CODE (call) == AGGR_INIT_EXPR
6318 || call == error_mark_node);
6319 return call;
6320 }
6321
6322 /* Returns true if FN has two parameters, of which the second has type
6323 size_t. */
6324
6325 static bool
second_parm_is_size_t(tree fn)6326 second_parm_is_size_t (tree fn)
6327 {
6328 tree t = FUNCTION_ARG_CHAIN (fn);
6329 if (!t || !same_type_p (TREE_VALUE (t), size_type_node))
6330 return false;
6331 t = TREE_CHAIN (t);
6332 if (t == void_list_node)
6333 return true;
6334 return false;
6335 }
6336
6337 /* True if T, an allocation function, has std::align_val_t as its second
6338 argument. */
6339
6340 bool
aligned_allocation_fn_p(tree t)6341 aligned_allocation_fn_p (tree t)
6342 {
6343 if (!aligned_new_threshold)
6344 return false;
6345
6346 tree a = FUNCTION_ARG_CHAIN (t);
6347 return (a && same_type_p (TREE_VALUE (a), align_type_node));
6348 }
6349
6350 /* True if T is std::destroying_delete_t. */
6351
6352 static bool
std_destroying_delete_t_p(tree t)6353 std_destroying_delete_t_p (tree t)
6354 {
6355 return (TYPE_CONTEXT (t) == std_node
6356 && id_equal (TYPE_IDENTIFIER (t), "destroying_delete_t"));
6357 }
6358
6359 /* A deallocation function with at least two parameters whose second parameter
6360 type is of type std::destroying_delete_t is a destroying operator delete. A
6361 destroying operator delete shall be a class member function named operator
6362 delete. [ Note: Array deletion cannot use a destroying operator
6363 delete. --end note ] */
6364
6365 tree
destroying_delete_p(tree t)6366 destroying_delete_p (tree t)
6367 {
6368 tree a = TYPE_ARG_TYPES (TREE_TYPE (t));
6369 if (!a || !TREE_CHAIN (a))
6370 return NULL_TREE;
6371 tree type = TREE_VALUE (TREE_CHAIN (a));
6372 return std_destroying_delete_t_p (type) ? type : NULL_TREE;
6373 }
6374
6375 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
6376 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of
6377 std::align_val_t. */
6378
6379 static bool
aligned_deallocation_fn_p(tree t)6380 aligned_deallocation_fn_p (tree t)
6381 {
6382 if (!aligned_new_threshold)
6383 return false;
6384
6385 /* A template instance is never a usual deallocation function,
6386 regardless of its signature. */
6387 if (TREE_CODE (t) == TEMPLATE_DECL
6388 || primary_template_specialization_p (t))
6389 return false;
6390
6391 tree a = FUNCTION_ARG_CHAIN (t);
6392 if (destroying_delete_p (t))
6393 a = TREE_CHAIN (a);
6394 if (same_type_p (TREE_VALUE (a), align_type_node)
6395 && TREE_CHAIN (a) == void_list_node)
6396 return true;
6397 if (!same_type_p (TREE_VALUE (a), size_type_node))
6398 return false;
6399 a = TREE_CHAIN (a);
6400 if (a && same_type_p (TREE_VALUE (a), align_type_node)
6401 && TREE_CHAIN (a) == void_list_node)
6402 return true;
6403 return false;
6404 }
6405
6406 /* Returns true if FN is a usual deallocation fn with a size_t parameter. */
6407
6408 static bool
sized_deallocation_fn_p(tree fn)6409 sized_deallocation_fn_p (tree fn)
6410 {
6411 tree t = FUNCTION_ARG_CHAIN (fn);
6412 if (destroying_delete_p (fn))
6413 t = TREE_CHAIN (t);
6414 if (!t || !same_type_p (TREE_VALUE (t), size_type_node))
6415 return false;
6416 t = TREE_CHAIN (t);
6417 if (t == void_list_node)
6418 return true;
6419 if (aligned_new_threshold && t
6420 && same_type_p (TREE_VALUE (t), align_type_node)
6421 && TREE_CHAIN (t) == void_list_node)
6422 return true;
6423 return false;
6424 }
6425
6426 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
6427 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
6428
6429 bool
usual_deallocation_fn_p(tree t)6430 usual_deallocation_fn_p (tree t)
6431 {
6432 /* A template instance is never a usual deallocation function,
6433 regardless of its signature. */
6434 if (TREE_CODE (t) == TEMPLATE_DECL
6435 || primary_template_specialization_p (t))
6436 return false;
6437
6438 /* A usual deallocation function is a deallocation function whose parameters
6439 after the first are
6440 - optionally, a parameter of type std::destroying_delete_t, then
6441 - optionally, a parameter of type std::size_t, then
6442 - optionally, a parameter of type std::align_val_t. */
6443 bool global = DECL_NAMESPACE_SCOPE_P (t);
6444 tree chain = FUNCTION_ARG_CHAIN (t);
6445 if (!chain)
6446 return false;
6447 if (destroying_delete_p (t))
6448 chain = TREE_CHAIN (chain);
6449 if (chain == void_list_node
6450 || ((!global || flag_sized_deallocation)
6451 && sized_deallocation_fn_p (t)))
6452 return true;
6453 if (aligned_deallocation_fn_p (t))
6454 return true;
6455 return false;
6456 }
6457
6458 /* Build a call to operator delete. This has to be handled very specially,
6459 because the restrictions on what signatures match are different from all
6460 other call instances. For a normal delete, only a delete taking (void *)
6461 or (void *, size_t) is accepted. For a placement delete, only an exact
6462 match with the placement new is accepted.
6463
6464 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
6465 ADDR is the pointer to be deleted.
6466 SIZE is the size of the memory block to be deleted.
6467 GLOBAL_P is true if the delete-expression should not consider
6468 class-specific delete operators.
6469 PLACEMENT is the corresponding placement new call, or NULL_TREE.
6470
6471 If this call to "operator delete" is being generated as part to
6472 deallocate memory allocated via a new-expression (as per [expr.new]
6473 which requires that if the initialization throws an exception then
6474 we call a deallocation function), then ALLOC_FN is the allocation
6475 function. */
6476
6477 tree
build_op_delete_call(enum tree_code code,tree addr,tree size,bool global_p,tree placement,tree alloc_fn,tsubst_flags_t complain)6478 build_op_delete_call (enum tree_code code, tree addr, tree size,
6479 bool global_p, tree placement,
6480 tree alloc_fn, tsubst_flags_t complain)
6481 {
6482 tree fn = NULL_TREE;
6483 tree fns, fnname, type, t;
6484
6485 if (addr == error_mark_node)
6486 return error_mark_node;
6487
6488 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
6489
6490 fnname = ovl_op_identifier (false, code);
6491
6492 if (CLASS_TYPE_P (type)
6493 && COMPLETE_TYPE_P (complete_type (type))
6494 && !global_p)
6495 /* In [class.free]
6496
6497 If the result of the lookup is ambiguous or inaccessible, or if
6498 the lookup selects a placement deallocation function, the
6499 program is ill-formed.
6500
6501 Therefore, we ask lookup_fnfields to complain about ambiguity. */
6502 {
6503 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
6504 if (fns == error_mark_node)
6505 return error_mark_node;
6506 }
6507 else
6508 fns = NULL_TREE;
6509
6510 if (fns == NULL_TREE)
6511 fns = lookup_name_nonclass (fnname);
6512
6513 /* Strip const and volatile from addr. */
6514 tree oaddr = addr;
6515 addr = cp_convert (ptr_type_node, addr, complain);
6516
6517 if (placement)
6518 {
6519 /* "A declaration of a placement deallocation function matches the
6520 declaration of a placement allocation function if it has the same
6521 number of parameters and, after parameter transformations (8.3.5),
6522 all parameter types except the first are identical."
6523
6524 So we build up the function type we want and ask instantiate_type
6525 to get it for us. */
6526 t = FUNCTION_ARG_CHAIN (alloc_fn);
6527 t = tree_cons (NULL_TREE, ptr_type_node, t);
6528 t = build_function_type (void_type_node, t);
6529
6530 fn = instantiate_type (t, fns, tf_none);
6531 if (fn == error_mark_node)
6532 return NULL_TREE;
6533
6534 fn = MAYBE_BASELINK_FUNCTIONS (fn);
6535
6536 /* "If the lookup finds the two-parameter form of a usual deallocation
6537 function (3.7.4.2) and that function, considered as a placement
6538 deallocation function, would have been selected as a match for the
6539 allocation function, the program is ill-formed." */
6540 if (second_parm_is_size_t (fn))
6541 {
6542 const char *const msg1
6543 = G_("exception cleanup for this placement new selects "
6544 "non-placement operator delete");
6545 const char *const msg2
6546 = G_("%qD is a usual (non-placement) deallocation "
6547 "function in C++14 (or with -fsized-deallocation)");
6548
6549 /* But if the class has an operator delete (void *), then that is
6550 the usual deallocation function, so we shouldn't complain
6551 about using the operator delete (void *, size_t). */
6552 if (DECL_CLASS_SCOPE_P (fn))
6553 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns));
6554 iter; ++iter)
6555 {
6556 tree elt = *iter;
6557 if (usual_deallocation_fn_p (elt)
6558 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
6559 goto ok;
6560 }
6561 /* Before C++14 a two-parameter global deallocation function is
6562 always a placement deallocation function, but warn if
6563 -Wc++14-compat. */
6564 else if (!flag_sized_deallocation)
6565 {
6566 if (complain & tf_warning)
6567 {
6568 auto_diagnostic_group d;
6569 if (warning (OPT_Wc__14_compat, msg1))
6570 inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
6571 }
6572 goto ok;
6573 }
6574
6575 if (complain & tf_warning_or_error)
6576 {
6577 auto_diagnostic_group d;
6578 if (permerror (input_location, msg1))
6579 {
6580 /* Only mention C++14 for namespace-scope delete. */
6581 if (DECL_NAMESPACE_SCOPE_P (fn))
6582 inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
6583 else
6584 inform (DECL_SOURCE_LOCATION (fn),
6585 "%qD is a usual (non-placement) deallocation "
6586 "function", fn);
6587 }
6588 }
6589 else
6590 return error_mark_node;
6591 ok:;
6592 }
6593 }
6594 else
6595 /* "Any non-placement deallocation function matches a non-placement
6596 allocation function. If the lookup finds a single matching
6597 deallocation function, that function will be called; otherwise, no
6598 deallocation function will be called." */
6599 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter)
6600 {
6601 tree elt = *iter;
6602 if (usual_deallocation_fn_p (elt))
6603 {
6604 if (!fn)
6605 {
6606 fn = elt;
6607 continue;
6608 }
6609
6610 /* -- If any of the deallocation functions is a destroying
6611 operator delete, all deallocation functions that are not
6612 destroying operator deletes are eliminated from further
6613 consideration. */
6614 bool fn_destroying = destroying_delete_p (fn);
6615 bool elt_destroying = destroying_delete_p (elt);
6616 if (elt_destroying != fn_destroying)
6617 {
6618 if (elt_destroying)
6619 fn = elt;
6620 continue;
6621 }
6622
6623 /* -- If the type has new-extended alignment, a function with a
6624 parameter of type std::align_val_t is preferred; otherwise a
6625 function without such a parameter is preferred. If exactly one
6626 preferred function is found, that function is selected and the
6627 selection process terminates. If more than one preferred
6628 function is found, all non-preferred functions are eliminated
6629 from further consideration. */
6630 if (aligned_new_threshold)
6631 {
6632 bool want_align = type_has_new_extended_alignment (type);
6633 bool fn_align = aligned_deallocation_fn_p (fn);
6634 bool elt_align = aligned_deallocation_fn_p (elt);
6635
6636 if (elt_align != fn_align)
6637 {
6638 if (want_align == elt_align)
6639 fn = elt;
6640 continue;
6641 }
6642 }
6643
6644 /* -- If the deallocation functions have class scope, the one
6645 without a parameter of type std::size_t is selected. */
6646 bool want_size;
6647 if (DECL_CLASS_SCOPE_P (fn))
6648 want_size = false;
6649
6650 /* -- If the type is complete and if, for the second alternative
6651 (delete array) only, the operand is a pointer to a class type
6652 with a non-trivial destructor or a (possibly multi-dimensional)
6653 array thereof, the function with a parameter of type std::size_t
6654 is selected.
6655
6656 -- Otherwise, it is unspecified whether a deallocation function
6657 with a parameter of type std::size_t is selected. */
6658 else
6659 {
6660 want_size = COMPLETE_TYPE_P (type);
6661 if (code == VEC_DELETE_EXPR
6662 && !TYPE_VEC_NEW_USES_COOKIE (type))
6663 /* We need a cookie to determine the array size. */
6664 want_size = false;
6665 }
6666 bool fn_size = sized_deallocation_fn_p (fn);
6667 bool elt_size = sized_deallocation_fn_p (elt);
6668 gcc_assert (fn_size != elt_size);
6669 if (want_size == elt_size)
6670 fn = elt;
6671 }
6672 }
6673
6674 /* If we have a matching function, call it. */
6675 if (fn)
6676 {
6677 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6678
6679 /* If the FN is a member function, make sure that it is
6680 accessible. */
6681 if (BASELINK_P (fns))
6682 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn,
6683 complain);
6684
6685 /* Core issue 901: It's ok to new a type with deleted delete. */
6686 if (DECL_DELETED_FN (fn) && alloc_fn)
6687 return NULL_TREE;
6688
6689 if (placement)
6690 {
6691 /* The placement args might not be suitable for overload
6692 resolution at this point, so build the call directly. */
6693 int nargs = call_expr_nargs (placement);
6694 tree *argarray = XALLOCAVEC (tree, nargs);
6695 int i;
6696 argarray[0] = addr;
6697 for (i = 1; i < nargs; i++)
6698 argarray[i] = CALL_EXPR_ARG (placement, i);
6699 if (!mark_used (fn, complain) && !(complain & tf_error))
6700 return error_mark_node;
6701 return build_cxx_call (fn, nargs, argarray, complain);
6702 }
6703 else
6704 {
6705 tree destroying = destroying_delete_p (fn);
6706 if (destroying)
6707 {
6708 /* Strip const and volatile from addr but retain the type of the
6709 object. */
6710 tree rtype = TREE_TYPE (TREE_TYPE (oaddr));
6711 rtype = cv_unqualified (rtype);
6712 rtype = TYPE_POINTER_TO (rtype);
6713 addr = cp_convert (rtype, oaddr, complain);
6714 destroying = build_functional_cast (destroying, NULL_TREE,
6715 complain);
6716 }
6717
6718 tree ret;
6719 vec<tree, va_gc> *args = make_tree_vector ();
6720 args->quick_push (addr);
6721 if (destroying)
6722 args->quick_push (destroying);
6723 if (sized_deallocation_fn_p (fn))
6724 args->quick_push (size);
6725 if (aligned_deallocation_fn_p (fn))
6726 {
6727 tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type));
6728 args->quick_push (al);
6729 }
6730 ret = cp_build_function_call_vec (fn, &args, complain);
6731 release_tree_vector (args);
6732 return ret;
6733 }
6734 }
6735
6736 /* [expr.new]
6737
6738 If no unambiguous matching deallocation function can be found,
6739 propagating the exception does not cause the object's memory to
6740 be freed. */
6741 if (alloc_fn)
6742 {
6743 if ((complain & tf_warning)
6744 && !placement)
6745 warning (0, "no corresponding deallocation function for %qD",
6746 alloc_fn);
6747 return NULL_TREE;
6748 }
6749
6750 if (complain & tf_error)
6751 error ("no suitable %<operator %s%> for %qT",
6752 OVL_OP_INFO (false, code)->name, type);
6753 return error_mark_node;
6754 }
6755
6756 /* Issue diagnostics about a disallowed access of DECL, using DIAG_DECL
6757 in the diagnostics.
6758
6759 If ISSUE_ERROR is true, then issue an error about the
6760 access, followed by a note showing the declaration.
6761 Otherwise, just show the note. */
6762
6763 void
complain_about_access(tree decl,tree diag_decl,bool issue_error)6764 complain_about_access (tree decl, tree diag_decl, bool issue_error)
6765 {
6766 if (TREE_PRIVATE (decl))
6767 {
6768 if (issue_error)
6769 error ("%q#D is private within this context", diag_decl);
6770 inform (DECL_SOURCE_LOCATION (diag_decl),
6771 "declared private here");
6772 }
6773 else if (TREE_PROTECTED (decl))
6774 {
6775 if (issue_error)
6776 error ("%q#D is protected within this context", diag_decl);
6777 inform (DECL_SOURCE_LOCATION (diag_decl),
6778 "declared protected here");
6779 }
6780 else
6781 {
6782 if (issue_error)
6783 error ("%q#D is inaccessible within this context", diag_decl);
6784 inform (DECL_SOURCE_LOCATION (diag_decl), "declared here");
6785 }
6786 }
6787
6788 /* If the current scope isn't allowed to access DECL along
6789 BASETYPE_PATH, give an error. The most derived class in
6790 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
6791 the declaration to use in the error diagnostic. */
6792
6793 bool
enforce_access(tree basetype_path,tree decl,tree diag_decl,tsubst_flags_t complain,access_failure_info * afi)6794 enforce_access (tree basetype_path, tree decl, tree diag_decl,
6795 tsubst_flags_t complain, access_failure_info *afi)
6796 {
6797 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
6798
6799 if (flag_new_inheriting_ctors
6800 && DECL_INHERITED_CTOR (decl))
6801 {
6802 /* 7.3.3/18: The additional constructors are accessible if they would be
6803 accessible when used to construct an object of the corresponding base
6804 class. */
6805 decl = strip_inheriting_ctors (decl);
6806 basetype_path = lookup_base (basetype_path, DECL_CONTEXT (decl),
6807 ba_any, NULL, complain);
6808 }
6809
6810 if (!accessible_p (basetype_path, decl, true))
6811 {
6812 if (flag_new_inheriting_ctors)
6813 diag_decl = strip_inheriting_ctors (diag_decl);
6814 if (complain & tf_error)
6815 complain_about_access (decl, diag_decl, true);
6816 if (afi)
6817 afi->record_access_failure (basetype_path, decl, diag_decl);
6818 return false;
6819 }
6820
6821 return true;
6822 }
6823
6824 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
6825 bitwise or of LOOKUP_* values. If any errors are warnings are
6826 generated, set *DIAGNOSTIC_FN to "error" or "warning",
6827 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
6828 to NULL. */
6829
6830 static tree
build_temp(tree expr,tree type,int flags,diagnostic_t * diagnostic_kind,tsubst_flags_t complain)6831 build_temp (tree expr, tree type, int flags,
6832 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
6833 {
6834 int savew, savee;
6835 vec<tree, va_gc> *args;
6836
6837 *diagnostic_kind = DK_UNSPECIFIED;
6838
6839 /* If the source is a packed field, calling the copy constructor will require
6840 binding the field to the reference parameter to the copy constructor, and
6841 we'll end up with an infinite loop. If we can use a bitwise copy, then
6842 do that now. */
6843 if ((lvalue_kind (expr) & clk_packed)
6844 && CLASS_TYPE_P (TREE_TYPE (expr))
6845 && !type_has_nontrivial_copy_init (TREE_TYPE (expr)))
6846 return get_target_expr_sfinae (expr, complain);
6847
6848 /* In decltype, we might have decided not to wrap this call in a TARGET_EXPR.
6849 But it turns out to be a subexpression, so perform temporary
6850 materialization now. */
6851 if (TREE_CODE (expr) == CALL_EXPR
6852 && CLASS_TYPE_P (type)
6853 && same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
6854 expr = build_cplus_new (type, expr, complain);
6855
6856 savew = warningcount + werrorcount, savee = errorcount;
6857 args = make_tree_vector_single (expr);
6858 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6859 &args, type, flags, complain);
6860 release_tree_vector (args);
6861 if (warningcount + werrorcount > savew)
6862 *diagnostic_kind = DK_WARNING;
6863 else if (errorcount > savee)
6864 *diagnostic_kind = DK_ERROR;
6865 return expr;
6866 }
6867
6868 /* Get any location for EXPR, falling back to input_location.
6869
6870 If the result is in a system header and is the virtual location for
6871 a token coming from the expansion of a macro, unwind it to the
6872 location of the expansion point of the macro (e.g. to avoid the
6873 diagnostic being suppressed for expansions of NULL where "NULL" is
6874 in a system header). */
6875
6876 static location_t
get_location_for_expr_unwinding_for_system_header(tree expr)6877 get_location_for_expr_unwinding_for_system_header (tree expr)
6878 {
6879 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
6880 loc = expansion_point_location_if_in_system_header (loc);
6881 return loc;
6882 }
6883
6884 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
6885 Also handle a subset of zero as null warnings.
6886 EXPR is implicitly converted to type TOTYPE.
6887 FN and ARGNUM are used for diagnostics. */
6888
6889 static void
conversion_null_warnings(tree totype,tree expr,tree fn,int argnum)6890 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
6891 {
6892 /* Issue warnings about peculiar, but valid, uses of NULL. */
6893 if (TREE_CODE (totype) != BOOLEAN_TYPE
6894 && ARITHMETIC_TYPE_P (totype)
6895 && null_node_p (expr))
6896 {
6897 location_t loc = get_location_for_expr_unwinding_for_system_header (expr);
6898 if (fn)
6899 {
6900 auto_diagnostic_group d;
6901 if (warning_at (loc, OPT_Wconversion_null,
6902 "passing NULL to non-pointer argument %P of %qD",
6903 argnum, fn))
6904 inform (get_fndecl_argument_location (fn, argnum),
6905 " declared here");
6906 }
6907 else
6908 warning_at (loc, OPT_Wconversion_null,
6909 "converting to non-pointer type %qT from NULL", totype);
6910 }
6911
6912 /* Issue warnings if "false" is converted to a NULL pointer */
6913 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE
6914 && TYPE_PTR_P (totype))
6915 {
6916 location_t loc = get_location_for_expr_unwinding_for_system_header (expr);
6917 if (fn)
6918 {
6919 auto_diagnostic_group d;
6920 if (warning_at (loc, OPT_Wconversion_null,
6921 "converting %<false%> to pointer type for argument "
6922 "%P of %qD", argnum, fn))
6923 inform (get_fndecl_argument_location (fn, argnum),
6924 " declared here");
6925 }
6926 else
6927 warning_at (loc, OPT_Wconversion_null,
6928 "converting %<false%> to pointer type %qT", totype);
6929 }
6930 /* Handle zero as null pointer warnings for cases other
6931 than EQ_EXPR and NE_EXPR */
6932 else if ((TYPE_PTR_OR_PTRMEM_P (totype) || NULLPTR_TYPE_P (totype))
6933 && null_ptr_cst_p (expr))
6934 {
6935 location_t loc = get_location_for_expr_unwinding_for_system_header (expr);
6936 maybe_warn_zero_as_null_pointer_constant (expr, loc);
6937 }
6938 }
6939
6940 /* We gave a diagnostic during a conversion. If this was in the second
6941 standard conversion sequence of a user-defined conversion sequence, say
6942 which user-defined conversion. */
6943
6944 static void
maybe_print_user_conv_context(conversion * convs)6945 maybe_print_user_conv_context (conversion *convs)
6946 {
6947 if (convs->user_conv_p)
6948 for (conversion *t = convs; t; t = next_conversion (t))
6949 if (t->kind == ck_user)
6950 {
6951 print_z_candidate (0, " after user-defined conversion:",
6952 t->cand);
6953 break;
6954 }
6955 }
6956
6957 /* Locate the parameter with the given index within FNDECL.
6958 ARGNUM is zero based, -1 indicates the `this' argument of a method.
6959 Return the location of the FNDECL itself if there are problems. */
6960
6961 location_t
get_fndecl_argument_location(tree fndecl,int argnum)6962 get_fndecl_argument_location (tree fndecl, int argnum)
6963 {
6964 /* The locations of implicitly-declared functions are likely to be
6965 more meaningful than those of their parameters. */
6966 if (DECL_ARTIFICIAL (fndecl))
6967 return DECL_SOURCE_LOCATION (fndecl);
6968
6969 int i;
6970 tree param;
6971
6972 /* Locate param by index within DECL_ARGUMENTS (fndecl). */
6973 for (i = 0, param = FUNCTION_FIRST_USER_PARM (fndecl);
6974 i < argnum && param;
6975 i++, param = TREE_CHAIN (param))
6976 ;
6977
6978 /* If something went wrong (e.g. if we have a builtin and thus no arguments),
6979 return the location of FNDECL. */
6980 if (param == NULL)
6981 return DECL_SOURCE_LOCATION (fndecl);
6982
6983 return DECL_SOURCE_LOCATION (param);
6984 }
6985
6986 /* If FNDECL is non-NULL, issue a note highlighting ARGNUM
6987 within its declaration (or the fndecl itself if something went
6988 wrong). */
6989
6990 void
maybe_inform_about_fndecl_for_bogus_argument_init(tree fn,int argnum)6991 maybe_inform_about_fndecl_for_bogus_argument_init (tree fn, int argnum)
6992 {
6993 if (fn)
6994 inform (get_fndecl_argument_location (fn, argnum),
6995 " initializing argument %P of %qD", argnum, fn);
6996 }
6997
6998 /* Perform the conversions in CONVS on the expression EXPR. FN and
6999 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
7000 indicates the `this' argument of a method. INNER is nonzero when
7001 being called to continue a conversion chain. It is negative when a
7002 reference binding will be applied, positive otherwise. If
7003 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
7004 conversions will be emitted if appropriate. If C_CAST_P is true,
7005 this conversion is coming from a C-style cast; in that case,
7006 conversions to inaccessible bases are permitted. */
7007
7008 static tree
convert_like_real(conversion * convs,tree expr,tree fn,int argnum,bool issue_conversion_warnings,bool c_cast_p,tsubst_flags_t complain)7009 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
7010 bool issue_conversion_warnings,
7011 bool c_cast_p, tsubst_flags_t complain)
7012 {
7013 tree totype = convs->type;
7014 diagnostic_t diag_kind;
7015 int flags;
7016 location_t loc = cp_expr_loc_or_loc (expr, input_location);
7017
7018 if (convs->bad_p && !(complain & tf_error))
7019 return error_mark_node;
7020
7021 if (convs->bad_p
7022 && convs->kind != ck_user
7023 && convs->kind != ck_list
7024 && convs->kind != ck_ambig
7025 && (convs->kind != ck_ref_bind
7026 || (convs->user_conv_p && next_conversion (convs)->bad_p))
7027 && (convs->kind != ck_rvalue
7028 || SCALAR_TYPE_P (totype))
7029 && convs->kind != ck_base)
7030 {
7031 bool complained = false;
7032 conversion *t = convs;
7033
7034 /* Give a helpful error if this is bad because of excess braces. */
7035 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
7036 && SCALAR_TYPE_P (totype)
7037 && CONSTRUCTOR_NELTS (expr) > 0
7038 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
7039 {
7040 complained = permerror (loc, "too many braces around initializer "
7041 "for %qT", totype);
7042 while (BRACE_ENCLOSED_INITIALIZER_P (expr)
7043 && CONSTRUCTOR_NELTS (expr) == 1)
7044 expr = CONSTRUCTOR_ELT (expr, 0)->value;
7045 }
7046
7047 /* Give a helpful error if this is bad because a conversion to bool
7048 from std::nullptr_t requires direct-initialization. */
7049 if (NULLPTR_TYPE_P (TREE_TYPE (expr))
7050 && TREE_CODE (totype) == BOOLEAN_TYPE)
7051 complained = permerror (loc, "converting to %qH from %qI requires "
7052 "direct-initialization",
7053 totype, TREE_TYPE (expr));
7054
7055 for (; t ; t = next_conversion (t))
7056 {
7057 if (t->kind == ck_user && t->cand->reason)
7058 {
7059 auto_diagnostic_group d;
7060 complained = permerror (loc, "invalid user-defined conversion "
7061 "from %qH to %qI", TREE_TYPE (expr),
7062 totype);
7063 if (complained)
7064 print_z_candidate (loc, "candidate is:", t->cand);
7065 expr = convert_like_real (t, expr, fn, argnum,
7066 /*issue_conversion_warnings=*/false,
7067 /*c_cast_p=*/false,
7068 complain);
7069 if (convs->kind == ck_ref_bind)
7070 expr = convert_to_reference (totype, expr, CONV_IMPLICIT,
7071 LOOKUP_NORMAL, NULL_TREE,
7072 complain);
7073 else
7074 expr = cp_convert (totype, expr, complain);
7075 if (complained)
7076 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7077 return expr;
7078 }
7079 else if (t->kind == ck_user || !t->bad_p)
7080 {
7081 expr = convert_like_real (t, expr, fn, argnum,
7082 /*issue_conversion_warnings=*/false,
7083 /*c_cast_p=*/false,
7084 complain);
7085 break;
7086 }
7087 else if (t->kind == ck_ambig)
7088 return convert_like_real (t, expr, fn, argnum,
7089 /*issue_conversion_warnings=*/false,
7090 /*c_cast_p=*/false,
7091 complain);
7092 else if (t->kind == ck_identity)
7093 break;
7094 }
7095 if (!complained)
7096 {
7097 range_label_for_type_mismatch label (TREE_TYPE (expr), totype);
7098 gcc_rich_location richloc (loc, &label);
7099 complained = permerror (&richloc,
7100 "invalid conversion from %qH to %qI",
7101 TREE_TYPE (expr), totype);
7102 }
7103 if (complained)
7104 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7105
7106 return cp_convert (totype, expr, complain);
7107 }
7108
7109 if (issue_conversion_warnings && (complain & tf_warning))
7110 conversion_null_warnings (totype, expr, fn, argnum);
7111
7112 switch (convs->kind)
7113 {
7114 case ck_user:
7115 {
7116 struct z_candidate *cand = convs->cand;
7117
7118 if (cand == NULL)
7119 /* We chose the surrogate function from add_conv_candidate, now we
7120 actually need to build the conversion. */
7121 cand = build_user_type_conversion_1 (totype, expr,
7122 LOOKUP_NO_CONVERSION, complain);
7123
7124 tree convfn = cand->fn;
7125
7126 /* When converting from an init list we consider explicit
7127 constructors, but actually trying to call one is an error. */
7128 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
7129 && BRACE_ENCLOSED_INITIALIZER_P (expr)
7130 /* Unless this is for direct-list-initialization. */
7131 && (!CONSTRUCTOR_IS_DIRECT_INIT (expr) || convs->need_temporary_p)
7132 /* And in C++98 a default constructor can't be explicit. */
7133 && cxx_dialect >= cxx11)
7134 {
7135 if (!(complain & tf_error))
7136 return error_mark_node;
7137 location_t loc = location_of (expr);
7138 if (CONSTRUCTOR_NELTS (expr) == 0
7139 && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node)
7140 {
7141 auto_diagnostic_group d;
7142 if (pedwarn (loc, 0, "converting to %qT from initializer list "
7143 "would use explicit constructor %qD",
7144 totype, convfn))
7145 inform (loc, "in C++11 and above a default constructor "
7146 "can be explicit");
7147 }
7148 else
7149 error ("converting to %qT from initializer list would use "
7150 "explicit constructor %qD", totype, convfn);
7151 }
7152
7153 /* If we're initializing from {}, it's value-initialization. */
7154 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
7155 && CONSTRUCTOR_NELTS (expr) == 0
7156 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype)
7157 && !processing_template_decl)
7158 {
7159 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr);
7160 if (abstract_virtuals_error_sfinae (NULL_TREE, totype, complain))
7161 return error_mark_node;
7162 expr = build_value_init (totype, complain);
7163 expr = get_target_expr_sfinae (expr, complain);
7164 if (expr != error_mark_node)
7165 {
7166 TARGET_EXPR_LIST_INIT_P (expr) = true;
7167 TARGET_EXPR_DIRECT_INIT_P (expr) = direct;
7168 }
7169 return expr;
7170 }
7171
7172 /* We don't know here whether EXPR is being used as an lvalue or
7173 rvalue, but we know it's read. */
7174 mark_exp_read (expr);
7175
7176 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow
7177 any more UDCs. */
7178 expr = build_over_call (cand, LOOKUP_NORMAL|LOOKUP_NO_CONVERSION,
7179 complain);
7180
7181 /* If this is a constructor or a function returning an aggr type,
7182 we need to build up a TARGET_EXPR. */
7183 if (DECL_CONSTRUCTOR_P (convfn))
7184 {
7185 expr = build_cplus_new (totype, expr, complain);
7186
7187 /* Remember that this was list-initialization. */
7188 if (convs->check_narrowing && expr != error_mark_node)
7189 TARGET_EXPR_LIST_INIT_P (expr) = true;
7190 }
7191
7192 return expr;
7193 }
7194 case ck_identity:
7195 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
7196 {
7197 int nelts = CONSTRUCTOR_NELTS (expr);
7198 if (nelts == 0)
7199 expr = build_value_init (totype, complain);
7200 else if (nelts == 1)
7201 expr = CONSTRUCTOR_ELT (expr, 0)->value;
7202 else
7203 gcc_unreachable ();
7204 }
7205 expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p,
7206 /*read_p=*/true, UNKNOWN_LOCATION,
7207 /*reject_builtin=*/true);
7208
7209 if (type_unknown_p (expr))
7210 expr = instantiate_type (totype, expr, complain);
7211 if (expr == null_node
7212 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
7213 /* If __null has been converted to an integer type, we do not want to
7214 continue to warn about uses of EXPR as an integer, rather than as a
7215 pointer. */
7216 expr = build_int_cst (totype, 0);
7217 return expr;
7218 case ck_ambig:
7219 /* We leave bad_p off ck_ambig because overload resolution considers
7220 it valid, it just fails when we try to perform it. So we need to
7221 check complain here, too. */
7222 if (complain & tf_error)
7223 {
7224 /* Call build_user_type_conversion again for the error. */
7225 int flags = (convs->need_temporary_p
7226 ? LOOKUP_IMPLICIT : LOOKUP_NORMAL);
7227 build_user_type_conversion (totype, convs->u.expr, flags, complain);
7228 gcc_assert (seen_error ());
7229 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7230 }
7231 return error_mark_node;
7232
7233 case ck_list:
7234 {
7235 /* Conversion to std::initializer_list<T>. */
7236 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
7237 unsigned len = CONSTRUCTOR_NELTS (expr);
7238 tree array;
7239
7240 if (len)
7241 {
7242 tree val; unsigned ix;
7243
7244 tree new_ctor = build_constructor (init_list_type_node, NULL);
7245
7246 /* Convert all the elements. */
7247 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
7248 {
7249 tree sub = convert_like_real (convs->u.list[ix], val, fn,
7250 argnum, false, false, complain);
7251 if (sub == error_mark_node)
7252 return sub;
7253 if (!BRACE_ENCLOSED_INITIALIZER_P (val)
7254 && !check_narrowing (TREE_TYPE (sub), val, complain))
7255 return error_mark_node;
7256 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor),
7257 NULL_TREE, sub);
7258 if (!TREE_CONSTANT (sub))
7259 TREE_CONSTANT (new_ctor) = false;
7260 }
7261 /* Build up the array. */
7262 elttype = cp_build_qualified_type
7263 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
7264 array = build_array_of_n_type (elttype, len);
7265 array = finish_compound_literal (array, new_ctor, complain);
7266 /* Take the address explicitly rather than via decay_conversion
7267 to avoid the error about taking the address of a temporary. */
7268 array = cp_build_addr_expr (array, complain);
7269 }
7270 else
7271 array = nullptr_node;
7272
7273 array = cp_convert (build_pointer_type (elttype), array, complain);
7274 if (array == error_mark_node)
7275 return error_mark_node;
7276
7277 /* Build up the initializer_list object. Note: fail gracefully
7278 if the object cannot be completed because, for example, no
7279 definition is provided (c++/80956). */
7280 totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain);
7281 if (!totype)
7282 return error_mark_node;
7283 tree field = next_initializable_field (TYPE_FIELDS (totype));
7284 vec<constructor_elt, va_gc> *vec = NULL;
7285 CONSTRUCTOR_APPEND_ELT (vec, field, array);
7286 field = next_initializable_field (DECL_CHAIN (field));
7287 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
7288 tree new_ctor = build_constructor (totype, vec);
7289 return get_target_expr_sfinae (new_ctor, complain);
7290 }
7291
7292 case ck_aggr:
7293 if (TREE_CODE (totype) == COMPLEX_TYPE)
7294 {
7295 tree real = CONSTRUCTOR_ELT (expr, 0)->value;
7296 tree imag = CONSTRUCTOR_ELT (expr, 1)->value;
7297 real = perform_implicit_conversion (TREE_TYPE (totype),
7298 real, complain);
7299 imag = perform_implicit_conversion (TREE_TYPE (totype),
7300 imag, complain);
7301 expr = build2 (COMPLEX_EXPR, totype, real, imag);
7302 return expr;
7303 }
7304 expr = reshape_init (totype, expr, complain);
7305 expr = get_target_expr_sfinae (digest_init (totype, expr, complain),
7306 complain);
7307 if (expr != error_mark_node)
7308 TARGET_EXPR_LIST_INIT_P (expr) = true;
7309 return expr;
7310
7311 default:
7312 break;
7313 };
7314
7315 expr = convert_like_real (next_conversion (convs), expr, fn, argnum,
7316 convs->kind == ck_ref_bind
7317 ? issue_conversion_warnings : false,
7318 c_cast_p, complain);
7319 if (expr == error_mark_node)
7320 return error_mark_node;
7321
7322 switch (convs->kind)
7323 {
7324 case ck_rvalue:
7325 expr = decay_conversion (expr, complain);
7326 if (expr == error_mark_node)
7327 {
7328 if (complain & tf_error)
7329 {
7330 auto_diagnostic_group d;
7331 maybe_print_user_conv_context (convs);
7332 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7333 }
7334 return error_mark_node;
7335 }
7336
7337 if (! MAYBE_CLASS_TYPE_P (totype))
7338 return expr;
7339
7340 /* Don't introduce copies when passing arguments along to the inherited
7341 constructor. */
7342 if (current_function_decl
7343 && flag_new_inheriting_ctors
7344 && DECL_INHERITED_CTOR (current_function_decl))
7345 return expr;
7346
7347 if (TREE_CODE (expr) == TARGET_EXPR
7348 && TARGET_EXPR_LIST_INIT_P (expr))
7349 /* Copy-list-initialization doesn't actually involve a copy. */
7350 return expr;
7351
7352 /* Fall through. */
7353 case ck_base:
7354 if (convs->kind == ck_base && !convs->need_temporary_p)
7355 {
7356 /* We are going to bind a reference directly to a base-class
7357 subobject of EXPR. */
7358 /* Build an expression for `*((base*) &expr)'. */
7359 expr = convert_to_base (expr, totype,
7360 !c_cast_p, /*nonnull=*/true, complain);
7361 return expr;
7362 }
7363
7364 /* Copy-initialization where the cv-unqualified version of the source
7365 type is the same class as, or a derived class of, the class of the
7366 destination [is treated as direct-initialization]. [dcl.init] */
7367 flags = LOOKUP_NORMAL;
7368 if (convs->user_conv_p)
7369 /* This conversion is being done in the context of a user-defined
7370 conversion (i.e. the second step of copy-initialization), so
7371 don't allow any more. */
7372 flags |= LOOKUP_NO_CONVERSION;
7373 else
7374 flags |= LOOKUP_ONLYCONVERTING;
7375 if (convs->rvaluedness_matches_p)
7376 /* standard_conversion got LOOKUP_PREFER_RVALUE. */
7377 flags |= LOOKUP_PREFER_RVALUE;
7378 expr = build_temp (expr, totype, flags, &diag_kind, complain);
7379 if (diag_kind && complain)
7380 {
7381 auto_diagnostic_group d;
7382 maybe_print_user_conv_context (convs);
7383 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7384 }
7385
7386 return build_cplus_new (totype, expr, complain);
7387
7388 case ck_ref_bind:
7389 {
7390 tree ref_type = totype;
7391
7392 if (convs->bad_p && !next_conversion (convs)->bad_p)
7393 {
7394 tree extype = TREE_TYPE (expr);
7395 auto_diagnostic_group d;
7396 if (TYPE_REF_IS_RVALUE (ref_type)
7397 && lvalue_p (expr))
7398 error_at (loc, "cannot bind rvalue reference of type %qH to "
7399 "lvalue of type %qI", totype, extype);
7400 else if (!TYPE_REF_IS_RVALUE (ref_type) && !lvalue_p (expr)
7401 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
7402 error_at (loc, "cannot bind non-const lvalue reference of "
7403 "type %qH to an rvalue of type %qI", totype, extype);
7404 else if (!reference_compatible_p (TREE_TYPE (totype), extype))
7405 error_at (loc, "binding reference of type %qH to %qI "
7406 "discards qualifiers", totype, extype);
7407 else
7408 gcc_unreachable ();
7409 maybe_print_user_conv_context (convs);
7410 maybe_inform_about_fndecl_for_bogus_argument_init (fn, argnum);
7411
7412 return error_mark_node;
7413 }
7414
7415 /* If necessary, create a temporary.
7416
7417 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
7418 that need temporaries, even when their types are reference
7419 compatible with the type of reference being bound, so the
7420 upcoming call to cp_build_addr_expr doesn't fail. */
7421 if (convs->need_temporary_p
7422 || TREE_CODE (expr) == CONSTRUCTOR
7423 || TREE_CODE (expr) == VA_ARG_EXPR)
7424 {
7425 /* Otherwise, a temporary of type "cv1 T1" is created and
7426 initialized from the initializer expression using the rules
7427 for a non-reference copy-initialization (8.5). */
7428
7429 tree type = TREE_TYPE (ref_type);
7430 cp_lvalue_kind lvalue = lvalue_kind (expr);
7431
7432 gcc_assert (same_type_ignoring_top_level_qualifiers_p
7433 (type, next_conversion (convs)->type));
7434 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
7435 && !TYPE_REF_IS_RVALUE (ref_type))
7436 {
7437 /* If the reference is volatile or non-const, we
7438 cannot create a temporary. */
7439 if (lvalue & clk_bitfield)
7440 error_at (loc, "cannot bind bitfield %qE to %qT",
7441 expr, ref_type);
7442 else if (lvalue & clk_packed)
7443 error_at (loc, "cannot bind packed field %qE to %qT",
7444 expr, ref_type);
7445 else
7446 error_at (loc, "cannot bind rvalue %qE to %qT",
7447 expr, ref_type);
7448 return error_mark_node;
7449 }
7450 /* If the source is a packed field, and we must use a copy
7451 constructor, then building the target expr will require
7452 binding the field to the reference parameter to the
7453 copy constructor, and we'll end up with an infinite
7454 loop. If we can use a bitwise copy, then we'll be
7455 OK. */
7456 if ((lvalue & clk_packed)
7457 && CLASS_TYPE_P (type)
7458 && type_has_nontrivial_copy_init (type))
7459 {
7460 error_at (loc, "cannot bind packed field %qE to %qT",
7461 expr, ref_type);
7462 return error_mark_node;
7463 }
7464 if (lvalue & clk_bitfield)
7465 {
7466 expr = convert_bitfield_to_declared_type (expr);
7467 expr = fold_convert (type, expr);
7468 }
7469 expr = build_target_expr_with_type (expr, type, complain);
7470 }
7471
7472 /* Take the address of the thing to which we will bind the
7473 reference. */
7474 expr = cp_build_addr_expr (expr, complain);
7475 if (expr == error_mark_node)
7476 return error_mark_node;
7477
7478 /* Convert it to a pointer to the type referred to by the
7479 reference. This will adjust the pointer if a derived to
7480 base conversion is being performed. */
7481 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
7482 expr, complain);
7483 /* Convert the pointer to the desired reference type. */
7484 return build_nop (ref_type, expr);
7485 }
7486
7487 case ck_lvalue:
7488 return decay_conversion (expr, complain);
7489
7490 case ck_fnptr:
7491 /* ??? Should the address of a transaction-safe pointer point to the TM
7492 clone, and this conversion look up the primary function? */
7493 return build_nop (totype, expr);
7494
7495 case ck_qual:
7496 /* Warn about deprecated conversion if appropriate. */
7497 if (complain & tf_warning)
7498 string_conv_p (totype, expr, 1);
7499 break;
7500
7501 case ck_ptr:
7502 if (convs->base_p)
7503 expr = convert_to_base (expr, totype, !c_cast_p,
7504 /*nonnull=*/false, complain);
7505 return build_nop (totype, expr);
7506
7507 case ck_pmem:
7508 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
7509 c_cast_p, complain);
7510
7511 default:
7512 break;
7513 }
7514
7515 if (convs->check_narrowing
7516 && !check_narrowing (totype, expr, complain,
7517 convs->check_narrowing_const_only))
7518 return error_mark_node;
7519
7520 warning_sentinel w (warn_zero_as_null_pointer_constant);
7521 if (issue_conversion_warnings)
7522 expr = cp_convert_and_check (totype, expr, complain);
7523 else
7524 expr = cp_convert (totype, expr, complain);
7525
7526 return expr;
7527 }
7528
7529 /* ARG is being passed to a varargs function. Perform any conversions
7530 required. Return the converted value. */
7531
7532 tree
convert_arg_to_ellipsis(tree arg,tsubst_flags_t complain)7533 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain)
7534 {
7535 tree arg_type;
7536 location_t loc = cp_expr_loc_or_loc (arg, input_location);
7537
7538 /* [expr.call]
7539
7540 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
7541 standard conversions are performed. */
7542 arg = decay_conversion (arg, complain);
7543 arg_type = TREE_TYPE (arg);
7544 /* [expr.call]
7545
7546 If the argument has integral or enumeration type that is subject
7547 to the integral promotions (_conv.prom_), or a floating point
7548 type that is subject to the floating point promotion
7549 (_conv.fpprom_), the value of the argument is converted to the
7550 promoted type before the call. */
7551 if (TREE_CODE (arg_type) == REAL_TYPE
7552 && (TYPE_PRECISION (arg_type)
7553 < TYPE_PRECISION (double_type_node))
7554 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
7555 {
7556 if ((complain & tf_warning)
7557 && warn_double_promotion && !c_inhibit_evaluation_warnings)
7558 warning_at (loc, OPT_Wdouble_promotion,
7559 "implicit conversion from %qH to %qI when passing "
7560 "argument to function",
7561 arg_type, double_type_node);
7562 arg = convert_to_real_nofold (double_type_node, arg);
7563 }
7564 else if (NULLPTR_TYPE_P (arg_type))
7565 {
7566 if (TREE_SIDE_EFFECTS (arg))
7567 arg = cp_build_compound_expr (arg, null_pointer_node, complain);
7568 else
7569 arg = null_pointer_node;
7570 }
7571 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
7572 {
7573 if (SCOPED_ENUM_P (arg_type))
7574 {
7575 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg,
7576 complain);
7577 prom = cp_perform_integral_promotions (prom, complain);
7578 if (abi_version_crosses (6)
7579 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type)
7580 && (complain & tf_warning))
7581 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as "
7582 "%qT before %<-fabi-version=6%>, %qT after", arg_type,
7583 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type));
7584 if (!abi_version_at_least (6))
7585 arg = prom;
7586 }
7587 else
7588 arg = cp_perform_integral_promotions (arg, complain);
7589 }
7590
7591 arg = require_complete_type_sfinae (arg, complain);
7592 arg_type = TREE_TYPE (arg);
7593
7594 if (arg != error_mark_node
7595 /* In a template (or ill-formed code), we can have an incomplete type
7596 even after require_complete_type_sfinae, in which case we don't know
7597 whether it has trivial copy or not. */
7598 && COMPLETE_TYPE_P (arg_type)
7599 && !cp_unevaluated_operand)
7600 {
7601 /* [expr.call] 5.2.2/7:
7602 Passing a potentially-evaluated argument of class type (Clause 9)
7603 with a non-trivial copy constructor or a non-trivial destructor
7604 with no corresponding parameter is conditionally-supported, with
7605 implementation-defined semantics.
7606
7607 We support it as pass-by-invisible-reference, just like a normal
7608 value parameter.
7609
7610 If the call appears in the context of a sizeof expression,
7611 it is not potentially-evaluated. */
7612 if (type_has_nontrivial_copy_init (arg_type)
7613 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type))
7614 {
7615 arg = force_rvalue (arg, complain);
7616 if (complain & tf_warning)
7617 warning (OPT_Wconditionally_supported,
7618 "passing objects of non-trivially-copyable "
7619 "type %q#T through %<...%> is conditionally supported",
7620 arg_type);
7621 return build1 (ADDR_EXPR, build_reference_type (arg_type), arg);
7622 }
7623 /* Build up a real lvalue-to-rvalue conversion in case the
7624 copy constructor is trivial but not callable. */
7625 else if (CLASS_TYPE_P (arg_type))
7626 force_rvalue (arg, complain);
7627
7628 }
7629
7630 return arg;
7631 }
7632
7633 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
7634
7635 tree
build_x_va_arg(location_t loc,tree expr,tree type)7636 build_x_va_arg (location_t loc, tree expr, tree type)
7637 {
7638 if (processing_template_decl)
7639 {
7640 tree r = build_min (VA_ARG_EXPR, type, expr);
7641 SET_EXPR_LOCATION (r, loc);
7642 return r;
7643 }
7644
7645 type = complete_type_or_else (type, NULL_TREE);
7646
7647 if (expr == error_mark_node || !type)
7648 return error_mark_node;
7649
7650 expr = mark_lvalue_use (expr);
7651
7652 if (TYPE_REF_P (type))
7653 {
7654 error ("cannot receive reference type %qT through %<...%>", type);
7655 return error_mark_node;
7656 }
7657
7658 if (type_has_nontrivial_copy_init (type)
7659 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
7660 {
7661 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat
7662 it as pass by invisible reference. */
7663 warning_at (loc, OPT_Wconditionally_supported,
7664 "receiving objects of non-trivially-copyable type %q#T "
7665 "through %<...%> is conditionally-supported", type);
7666
7667 tree ref = cp_build_reference_type (type, false);
7668 expr = build_va_arg (loc, expr, ref);
7669 return convert_from_reference (expr);
7670 }
7671
7672 tree ret = build_va_arg (loc, expr, type);
7673 if (CLASS_TYPE_P (type))
7674 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to
7675 know how to handle it. */
7676 ret = get_target_expr (ret);
7677 return ret;
7678 }
7679
7680 /* TYPE has been given to va_arg. Apply the default conversions which
7681 would have happened when passed via ellipsis. Return the promoted
7682 type, or the passed type if there is no change. */
7683
7684 tree
cxx_type_promotes_to(tree type)7685 cxx_type_promotes_to (tree type)
7686 {
7687 tree promote;
7688
7689 /* Perform the array-to-pointer and function-to-pointer
7690 conversions. */
7691 type = type_decays_to (type);
7692
7693 promote = type_promotes_to (type);
7694 if (same_type_p (type, promote))
7695 promote = type;
7696
7697 return promote;
7698 }
7699
7700 /* ARG is a default argument expression being passed to a parameter of
7701 the indicated TYPE, which is a parameter to FN. PARMNUM is the
7702 zero-based argument number. Do any required conversions. Return
7703 the converted value. */
7704
7705 static GTY(()) vec<tree, va_gc> *default_arg_context;
7706 void
push_defarg_context(tree fn)7707 push_defarg_context (tree fn)
7708 { vec_safe_push (default_arg_context, fn); }
7709
7710 void
pop_defarg_context(void)7711 pop_defarg_context (void)
7712 { default_arg_context->pop (); }
7713
7714 tree
convert_default_arg(tree type,tree arg,tree fn,int parmnum,tsubst_flags_t complain)7715 convert_default_arg (tree type, tree arg, tree fn, int parmnum,
7716 tsubst_flags_t complain)
7717 {
7718 int i;
7719 tree t;
7720
7721 /* See through clones. */
7722 fn = DECL_ORIGIN (fn);
7723 /* And inheriting ctors. */
7724 if (flag_new_inheriting_ctors)
7725 fn = strip_inheriting_ctors (fn);
7726
7727 /* Detect recursion. */
7728 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t)
7729 if (t == fn)
7730 {
7731 if (complain & tf_error)
7732 error ("recursive evaluation of default argument for %q#D", fn);
7733 return error_mark_node;
7734 }
7735
7736 /* If the ARG is an unparsed default argument expression, the
7737 conversion cannot be performed. */
7738 if (TREE_CODE (arg) == DEFAULT_ARG)
7739 {
7740 if (complain & tf_error)
7741 error ("call to %qD uses the default argument for parameter %P, which "
7742 "is not yet defined", fn, parmnum);
7743 return error_mark_node;
7744 }
7745
7746 push_defarg_context (fn);
7747
7748 if (fn && DECL_TEMPLATE_INFO (fn))
7749 arg = tsubst_default_argument (fn, parmnum, type, arg, complain);
7750
7751 /* Due to:
7752
7753 [dcl.fct.default]
7754
7755 The names in the expression are bound, and the semantic
7756 constraints are checked, at the point where the default
7757 expressions appears.
7758
7759 we must not perform access checks here. */
7760 push_deferring_access_checks (dk_no_check);
7761 /* We must make a copy of ARG, in case subsequent processing
7762 alters any part of it. */
7763 arg = break_out_target_exprs (arg, /*clear location*/true);
7764
7765 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
7766 ICR_DEFAULT_ARGUMENT, fn, parmnum,
7767 complain);
7768 arg = convert_for_arg_passing (type, arg, complain);
7769 pop_deferring_access_checks();
7770
7771 pop_defarg_context ();
7772
7773 return arg;
7774 }
7775
7776 /* Returns the type which will really be used for passing an argument of
7777 type TYPE. */
7778
7779 tree
type_passed_as(tree type)7780 type_passed_as (tree type)
7781 {
7782 /* Pass classes with copy ctors by invisible reference. */
7783 if (TREE_ADDRESSABLE (type))
7784 {
7785 type = build_reference_type (type);
7786 /* There are no other pointers to this temporary. */
7787 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
7788 }
7789 else if (targetm.calls.promote_prototypes (NULL_TREE)
7790 && INTEGRAL_TYPE_P (type)
7791 && COMPLETE_TYPE_P (type)
7792 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
7793 type = integer_type_node;
7794
7795 return type;
7796 }
7797
7798 /* Actually perform the appropriate conversion. */
7799
7800 tree
convert_for_arg_passing(tree type,tree val,tsubst_flags_t complain)7801 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain)
7802 {
7803 tree bitfield_type;
7804
7805 /* If VAL is a bitfield, then -- since it has already been converted
7806 to TYPE -- it cannot have a precision greater than TYPE.
7807
7808 If it has a smaller precision, we must widen it here. For
7809 example, passing "int f:3;" to a function expecting an "int" will
7810 not result in any conversion before this point.
7811
7812 If the precision is the same we must not risk widening. For
7813 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
7814 often have type "int", even though the C++ type for the field is
7815 "long long". If the value is being passed to a function
7816 expecting an "int", then no conversions will be required. But,
7817 if we call convert_bitfield_to_declared_type, the bitfield will
7818 be converted to "long long". */
7819 bitfield_type = is_bitfield_expr_with_lowered_type (val);
7820 if (bitfield_type
7821 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
7822 val = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type), val);
7823
7824 if (val == error_mark_node)
7825 ;
7826 /* Pass classes with copy ctors by invisible reference. */
7827 else if (TREE_ADDRESSABLE (type))
7828 val = build1 (ADDR_EXPR, build_reference_type (type), val);
7829 else if (targetm.calls.promote_prototypes (NULL_TREE)
7830 && INTEGRAL_TYPE_P (type)
7831 && COMPLETE_TYPE_P (type)
7832 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
7833 val = cp_perform_integral_promotions (val, complain);
7834 if (complain & tf_warning)
7835 {
7836 if (warn_suggest_attribute_format)
7837 {
7838 tree rhstype = TREE_TYPE (val);
7839 const enum tree_code coder = TREE_CODE (rhstype);
7840 const enum tree_code codel = TREE_CODE (type);
7841 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
7842 && coder == codel
7843 && check_missing_format_attribute (type, rhstype))
7844 warning (OPT_Wsuggest_attribute_format,
7845 "argument of function call might be a candidate "
7846 "for a format attribute");
7847 }
7848 maybe_warn_parm_abi (type, cp_expr_loc_or_loc (val, input_location));
7849 }
7850
7851 if (complain & tf_warning)
7852 warn_for_address_or_pointer_of_packed_member (type, val);
7853
7854 return val;
7855 }
7856
7857 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for
7858 which just decay_conversion or no conversions at all should be done.
7859 This is true for some builtins which don't act like normal functions.
7860 Return 2 if no conversions at all should be done, 1 if just
7861 decay_conversion. Return 3 for special treatment of the 3rd argument
7862 for __builtin_*_overflow_p. */
7863
7864 int
magic_varargs_p(tree fn)7865 magic_varargs_p (tree fn)
7866 {
7867 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
7868 switch (DECL_FUNCTION_CODE (fn))
7869 {
7870 case BUILT_IN_CLASSIFY_TYPE:
7871 case BUILT_IN_CONSTANT_P:
7872 case BUILT_IN_NEXT_ARG:
7873 case BUILT_IN_VA_START:
7874 return 1;
7875
7876 case BUILT_IN_ADD_OVERFLOW_P:
7877 case BUILT_IN_SUB_OVERFLOW_P:
7878 case BUILT_IN_MUL_OVERFLOW_P:
7879 return 3;
7880
7881 default:;
7882 return lookup_attribute ("type generic",
7883 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
7884 }
7885
7886 return 0;
7887 }
7888
7889 /* Returns the decl of the dispatcher function if FN is a function version. */
7890
7891 tree
get_function_version_dispatcher(tree fn)7892 get_function_version_dispatcher (tree fn)
7893 {
7894 tree dispatcher_decl = NULL;
7895
7896 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
7897 && DECL_FUNCTION_VERSIONED (fn));
7898
7899 gcc_assert (targetm.get_function_versions_dispatcher);
7900 dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
7901
7902 if (dispatcher_decl == NULL)
7903 {
7904 error_at (input_location, "use of multiversioned function "
7905 "without a default");
7906 return NULL;
7907 }
7908
7909 retrofit_lang_decl (dispatcher_decl);
7910 gcc_assert (dispatcher_decl != NULL);
7911 return dispatcher_decl;
7912 }
7913
7914 /* fn is a function version dispatcher that is marked used. Mark all the
7915 semantically identical function versions it will dispatch as used. */
7916
7917 void
mark_versions_used(tree fn)7918 mark_versions_used (tree fn)
7919 {
7920 struct cgraph_node *node;
7921 struct cgraph_function_version_info *node_v;
7922 struct cgraph_function_version_info *it_v;
7923
7924 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7925
7926 node = cgraph_node::get (fn);
7927 if (node == NULL)
7928 return;
7929
7930 gcc_assert (node->dispatcher_function);
7931
7932 node_v = node->function_version ();
7933 if (node_v == NULL)
7934 return;
7935
7936 /* All semantically identical versions are chained. Traverse and mark each
7937 one of them as used. */
7938 it_v = node_v->next;
7939 while (it_v != NULL)
7940 {
7941 mark_used (it_v->this_node->decl);
7942 it_v = it_v->next;
7943 }
7944 }
7945
7946 /* Build a call to "the copy constructor" for the type of A, even if it
7947 wouldn't be selected by normal overload resolution. Used for
7948 diagnostics. */
7949
7950 static tree
call_copy_ctor(tree a,tsubst_flags_t complain)7951 call_copy_ctor (tree a, tsubst_flags_t complain)
7952 {
7953 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a));
7954 tree binfo = TYPE_BINFO (ctype);
7955 tree copy = get_copy_ctor (ctype, complain);
7956 copy = build_baselink (binfo, binfo, copy, NULL_TREE);
7957 tree ob = build_dummy_object (ctype);
7958 vec<tree, va_gc>* args = make_tree_vector_single (a);
7959 tree r = build_new_method_call (ob, copy, &args, NULL_TREE,
7960 LOOKUP_NORMAL, NULL, complain);
7961 release_tree_vector (args);
7962 return r;
7963 }
7964
7965 /* Return true iff T refers to a base field. */
7966
7967 static bool
is_base_field_ref(tree t)7968 is_base_field_ref (tree t)
7969 {
7970 STRIP_NOPS (t);
7971 if (TREE_CODE (t) == ADDR_EXPR)
7972 t = TREE_OPERAND (t, 0);
7973 if (TREE_CODE (t) == COMPONENT_REF)
7974 t = TREE_OPERAND (t, 1);
7975 if (TREE_CODE (t) == FIELD_DECL)
7976 return DECL_FIELD_IS_BASE (t);
7977 return false;
7978 }
7979
7980 /* We can't elide a copy from a function returning by value to a base
7981 subobject, as the callee might clobber tail padding. Return true iff this
7982 could be that case. */
7983
7984 static bool
unsafe_copy_elision_p(tree target,tree exp)7985 unsafe_copy_elision_p (tree target, tree exp)
7986 {
7987 /* Copy elision only happens with a TARGET_EXPR. */
7988 if (TREE_CODE (exp) != TARGET_EXPR)
7989 return false;
7990 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
7991 /* It's safe to elide the copy for a class with no tail padding. */
7992 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type)))
7993 return false;
7994 /* It's safe to elide the copy if we aren't initializing a base object. */
7995 if (!is_base_field_ref (target))
7996 return false;
7997 tree init = TARGET_EXPR_INITIAL (exp);
7998 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */
7999 while (TREE_CODE (init) == COMPOUND_EXPR)
8000 init = TREE_OPERAND (init, 1);
8001 if (TREE_CODE (init) == COND_EXPR)
8002 {
8003 /* We'll end up copying from each of the arms of the COND_EXPR directly
8004 into the target, so look at them. */
8005 if (tree op = TREE_OPERAND (init, 1))
8006 if (unsafe_copy_elision_p (target, op))
8007 return true;
8008 return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2));
8009 }
8010 return (TREE_CODE (init) == AGGR_INIT_EXPR
8011 && !AGGR_INIT_VIA_CTOR_P (init));
8012 }
8013
8014 /* True iff C is a conversion that binds a reference to a prvalue. */
8015
8016 static bool
conv_binds_ref_to_prvalue(conversion * c)8017 conv_binds_ref_to_prvalue (conversion *c)
8018 {
8019 if (c->kind != ck_ref_bind)
8020 return false;
8021 if (c->need_temporary_p)
8022 return true;
8023
8024 c = next_conversion (c);
8025
8026 if (c->kind == ck_rvalue)
8027 return true;
8028 if (c->kind == ck_user && !TYPE_REF_P (c->type))
8029 return true;
8030 if (c->kind == ck_identity && c->u.expr
8031 && TREE_CODE (c->u.expr) == TARGET_EXPR)
8032 return true;
8033
8034 return false;
8035 }
8036
8037 /* Call the trivial destructor for INSTANCE, which can be either an lvalue of
8038 class type or a pointer to class type. */
8039
8040 tree
build_trivial_dtor_call(tree instance)8041 build_trivial_dtor_call (tree instance)
8042 {
8043 gcc_assert (!is_dummy_object (instance));
8044
8045 if (!flag_lifetime_dse)
8046 {
8047 no_clobber:
8048 return fold_convert (void_type_node, instance);
8049 }
8050
8051 if (INDIRECT_TYPE_P (TREE_TYPE (instance)))
8052 {
8053 if (VOID_TYPE_P (TREE_TYPE (TREE_TYPE (instance))))
8054 goto no_clobber;
8055 instance = cp_build_fold_indirect_ref (instance);
8056 }
8057
8058 /* A trivial destructor should still clobber the object. */
8059 tree clobber = build_clobber (TREE_TYPE (instance));
8060 return build2 (MODIFY_EXPR, void_type_node,
8061 instance, clobber);
8062 }
8063
8064 /* Subroutine of the various build_*_call functions. Overload resolution
8065 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
8066 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
8067 bitmask of various LOOKUP_* flags which apply to the call itself. */
8068
8069 static tree
build_over_call(struct z_candidate * cand,int flags,tsubst_flags_t complain)8070 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
8071 {
8072 tree fn = cand->fn;
8073 const vec<tree, va_gc> *args = cand->args;
8074 tree first_arg = cand->first_arg;
8075 conversion **convs = cand->convs;
8076 conversion *conv;
8077 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
8078 int parmlen;
8079 tree val;
8080 int i = 0;
8081 int j = 0;
8082 unsigned int arg_index = 0;
8083 int is_method = 0;
8084 int nargs;
8085 tree *argarray;
8086 bool already_used = false;
8087
8088 /* In a template, there is no need to perform all of the work that
8089 is normally done. We are only interested in the type of the call
8090 expression, i.e., the return type of the function. Any semantic
8091 errors will be deferred until the template is instantiated. */
8092 if (processing_template_decl)
8093 {
8094 tree expr, addr;
8095 tree return_type;
8096 const tree *argarray;
8097 unsigned int nargs;
8098
8099 if (undeduced_auto_decl (fn))
8100 mark_used (fn, complain);
8101 else
8102 /* Otherwise set TREE_USED for the benefit of -Wunused-function.
8103 See PR80598. */
8104 TREE_USED (fn) = 1;
8105
8106 return_type = TREE_TYPE (TREE_TYPE (fn));
8107 nargs = vec_safe_length (args);
8108 if (first_arg == NULL_TREE)
8109 argarray = args->address ();
8110 else
8111 {
8112 tree *alcarray;
8113 unsigned int ix;
8114 tree arg;
8115
8116 ++nargs;
8117 alcarray = XALLOCAVEC (tree, nargs);
8118 alcarray[0] = build_this (first_arg);
8119 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
8120 alcarray[ix + 1] = arg;
8121 argarray = alcarray;
8122 }
8123
8124 addr = build_addr_func (fn, complain);
8125 if (addr == error_mark_node)
8126 return error_mark_node;
8127 expr = build_call_array_loc (input_location, return_type,
8128 addr, nargs, argarray);
8129 if (TREE_THIS_VOLATILE (fn) && cfun)
8130 current_function_returns_abnormally = 1;
8131 return convert_from_reference (expr);
8132 }
8133
8134 /* Give any warnings we noticed during overload resolution. */
8135 if (cand->warnings && (complain & tf_warning))
8136 {
8137 struct candidate_warning *w;
8138 for (w = cand->warnings; w; w = w->next)
8139 joust (cand, w->loser, 1, complain);
8140 }
8141
8142 /* Core issue 2327: P0135 doesn't say how to handle the case where the
8143 argument to the copy constructor ends up being a prvalue after
8144 conversion. Let's do the normal processing, but pretend we aren't
8145 actually using the copy constructor. */
8146 bool force_elide = false;
8147 if (cxx_dialect >= cxx17
8148 && cand->num_convs == 1
8149 && DECL_COMPLETE_CONSTRUCTOR_P (fn)
8150 && (DECL_COPY_CONSTRUCTOR_P (fn)
8151 || DECL_MOVE_CONSTRUCTOR_P (fn))
8152 && conv_binds_ref_to_prvalue (convs[0]))
8153 {
8154 force_elide = true;
8155 goto not_really_used;
8156 }
8157
8158 /* OK, we're actually calling this inherited constructor; set its deletedness
8159 appropriately. We can get away with doing this here because calling is
8160 the only way to refer to a constructor. */
8161 if (DECL_INHERITED_CTOR (fn))
8162 deduce_inheriting_ctor (fn);
8163
8164 /* Make =delete work with SFINAE. */
8165 if (DECL_DELETED_FN (fn))
8166 {
8167 if (complain & tf_error)
8168 mark_used (fn);
8169 return error_mark_node;
8170 }
8171
8172 if (DECL_FUNCTION_MEMBER_P (fn))
8173 {
8174 tree access_fn;
8175 /* If FN is a template function, two cases must be considered.
8176 For example:
8177
8178 struct A {
8179 protected:
8180 template <class T> void f();
8181 };
8182 template <class T> struct B {
8183 protected:
8184 void g();
8185 };
8186 struct C : A, B<int> {
8187 using A::f; // #1
8188 using B<int>::g; // #2
8189 };
8190
8191 In case #1 where `A::f' is a member template, DECL_ACCESS is
8192 recorded in the primary template but not in its specialization.
8193 We check access of FN using its primary template.
8194
8195 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
8196 because it is a member of class template B, DECL_ACCESS is
8197 recorded in the specialization `B<int>::g'. We cannot use its
8198 primary template because `B<T>::g' and `B<int>::g' may have
8199 different access. */
8200 if (DECL_TEMPLATE_INFO (fn)
8201 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
8202 access_fn = DECL_TI_TEMPLATE (fn);
8203 else
8204 access_fn = fn;
8205 if (!perform_or_defer_access_check (cand->access_path, access_fn,
8206 fn, complain))
8207 return error_mark_node;
8208 }
8209
8210 /* If we're checking for implicit delete, don't bother with argument
8211 conversions. */
8212 if (flags & LOOKUP_SPECULATIVE)
8213 {
8214 if (cand->viable == 1)
8215 return fn;
8216 else if (!(complain & tf_error))
8217 /* Reject bad conversions now. */
8218 return error_mark_node;
8219 /* else continue to get conversion error. */
8220 }
8221
8222 not_really_used:
8223
8224 /* N3276 magic doesn't apply to nested calls. */
8225 tsubst_flags_t decltype_flag = (complain & tf_decltype);
8226 complain &= ~tf_decltype;
8227 /* No-Cleanup doesn't apply to nested calls either. */
8228 tsubst_flags_t no_cleanup_complain = complain;
8229 complain &= ~tf_no_cleanup;
8230
8231 /* Find maximum size of vector to hold converted arguments. */
8232 parmlen = list_length (parm);
8233 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0);
8234 if (parmlen > nargs)
8235 nargs = parmlen;
8236 argarray = XALLOCAVEC (tree, nargs);
8237
8238 /* The implicit parameters to a constructor are not considered by overload
8239 resolution, and must be of the proper type. */
8240 if (DECL_CONSTRUCTOR_P (fn))
8241 {
8242 tree object_arg;
8243 if (first_arg != NULL_TREE)
8244 {
8245 object_arg = first_arg;
8246 first_arg = NULL_TREE;
8247 }
8248 else
8249 {
8250 object_arg = (*args)[arg_index];
8251 ++arg_index;
8252 }
8253 argarray[j++] = build_this (object_arg);
8254 parm = TREE_CHAIN (parm);
8255 /* We should never try to call the abstract constructor. */
8256 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
8257
8258 if (DECL_HAS_VTT_PARM_P (fn))
8259 {
8260 argarray[j++] = (*args)[arg_index];
8261 ++arg_index;
8262 parm = TREE_CHAIN (parm);
8263 }
8264
8265 if (flags & LOOKUP_PREFER_RVALUE)
8266 {
8267 /* The implicit move specified in 15.8.3/3 fails "...if the type of
8268 the first parameter of the selected constructor is not an rvalue
8269 reference to the object's type (possibly cv-qualified)...." */
8270 gcc_assert (!(complain & tf_error));
8271 tree ptype = convs[0]->type;
8272 if (!TYPE_REF_P (ptype)
8273 || !TYPE_REF_IS_RVALUE (ptype)
8274 || CONVERSION_RANK (convs[0]) > cr_exact)
8275 return error_mark_node;
8276 }
8277 }
8278 /* Bypass access control for 'this' parameter. */
8279 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
8280 {
8281 tree parmtype = TREE_VALUE (parm);
8282 tree arg = build_this (first_arg != NULL_TREE
8283 ? first_arg
8284 : (*args)[arg_index]);
8285 tree argtype = TREE_TYPE (arg);
8286 tree converted_arg;
8287 tree base_binfo;
8288
8289 if (arg == error_mark_node)
8290 return error_mark_node;
8291
8292 if (convs[i]->bad_p)
8293 {
8294 if (complain & tf_error)
8295 {
8296 auto_diagnostic_group d;
8297 if (permerror (input_location, "passing %qT as %<this%> "
8298 "argument discards qualifiers",
8299 TREE_TYPE (argtype)))
8300 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn);
8301 }
8302 else
8303 return error_mark_node;
8304 }
8305
8306 /* See if the function member or the whole class type is declared
8307 final and the call can be devirtualized. */
8308 if (DECL_FINAL_P (fn)
8309 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn))))
8310 flags |= LOOKUP_NONVIRTUAL;
8311
8312 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
8313 X is called for an object that is not of type X, or of a type
8314 derived from X, the behavior is undefined.
8315
8316 So we can assume that anything passed as 'this' is non-null, and
8317 optimize accordingly. */
8318 gcc_assert (TYPE_PTR_P (parmtype));
8319 /* Convert to the base in which the function was declared. */
8320 gcc_assert (cand->conversion_path != NULL_TREE);
8321 /* Check that the base class is accessible. */
8322 if (!accessible_base_p (TREE_TYPE (argtype),
8323 BINFO_TYPE (cand->conversion_path), true))
8324 {
8325 if (complain & tf_error)
8326 error ("%qT is not an accessible base of %qT",
8327 BINFO_TYPE (cand->conversion_path),
8328 TREE_TYPE (argtype));
8329 else
8330 return error_mark_node;
8331 }
8332 /* If fn was found by a using declaration, the conversion path
8333 will be to the derived class, not the base declaring fn. We
8334 must convert from derived to base. */
8335 base_binfo = lookup_base (cand->conversion_path,
8336 TREE_TYPE (parmtype), ba_unique,
8337 NULL, complain);
8338
8339 /* If we know the dynamic type of the object, look up the final overrider
8340 in the BINFO. */
8341 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0
8342 && resolves_to_fixed_type_p (arg))
8343 {
8344 tree ov = lookup_vfn_in_binfo (DECL_VINDEX (fn), base_binfo);
8345
8346 /* And unwind base_binfo to match. If we don't find the type we're
8347 looking for in BINFO_INHERITANCE_CHAIN, we're looking at diamond
8348 inheritance; for now do a normal virtual call in that case. */
8349 tree octx = DECL_CONTEXT (ov);
8350 tree obinfo = base_binfo;
8351 while (obinfo && !SAME_BINFO_TYPE_P (BINFO_TYPE (obinfo), octx))
8352 obinfo = BINFO_INHERITANCE_CHAIN (obinfo);
8353 if (obinfo)
8354 {
8355 fn = ov;
8356 base_binfo = obinfo;
8357 flags |= LOOKUP_NONVIRTUAL;
8358 }
8359 }
8360
8361 converted_arg = build_base_path (PLUS_EXPR, arg,
8362 base_binfo, 1, complain);
8363
8364 argarray[j++] = converted_arg;
8365 parm = TREE_CHAIN (parm);
8366 if (first_arg != NULL_TREE)
8367 first_arg = NULL_TREE;
8368 else
8369 ++arg_index;
8370 ++i;
8371 is_method = 1;
8372 }
8373
8374 gcc_assert (first_arg == NULL_TREE);
8375 for (; arg_index < vec_safe_length (args) && parm;
8376 parm = TREE_CHAIN (parm), ++arg_index, ++i)
8377 {
8378 tree type = TREE_VALUE (parm);
8379 tree arg = (*args)[arg_index];
8380 bool conversion_warning = true;
8381
8382 conv = convs[i];
8383
8384 /* If the argument is NULL and used to (implicitly) instantiate a
8385 template function (and bind one of the template arguments to
8386 the type of 'long int'), we don't want to warn about passing NULL
8387 to non-pointer argument.
8388 For example, if we have this template function:
8389
8390 template<typename T> void func(T x) {}
8391
8392 we want to warn (when -Wconversion is enabled) in this case:
8393
8394 void foo() {
8395 func<int>(NULL);
8396 }
8397
8398 but not in this case:
8399
8400 void foo() {
8401 func(NULL);
8402 }
8403 */
8404 if (null_node_p (arg)
8405 && DECL_TEMPLATE_INFO (fn)
8406 && cand->template_decl
8407 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS))
8408 conversion_warning = false;
8409
8410 /* Warn about initializer_list deduction that isn't currently in the
8411 working draft. */
8412 if (cxx_dialect > cxx98
8413 && flag_deduce_init_list
8414 && cand->template_decl
8415 && is_std_init_list (non_reference (type))
8416 && BRACE_ENCLOSED_INITIALIZER_P (arg))
8417 {
8418 tree tmpl = TI_TEMPLATE (cand->template_decl);
8419 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
8420 tree patparm = get_pattern_parm (realparm, tmpl);
8421 tree pattype = TREE_TYPE (patparm);
8422 if (PACK_EXPANSION_P (pattype))
8423 pattype = PACK_EXPANSION_PATTERN (pattype);
8424 pattype = non_reference (pattype);
8425
8426 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
8427 && (cand->explicit_targs == NULL_TREE
8428 || (TREE_VEC_LENGTH (cand->explicit_targs)
8429 <= TEMPLATE_TYPE_IDX (pattype))))
8430 {
8431 pedwarn (input_location, 0, "deducing %qT as %qT",
8432 non_reference (TREE_TYPE (patparm)),
8433 non_reference (type));
8434 pedwarn (DECL_SOURCE_LOCATION (cand->fn), 0,
8435 " in call to %qD", cand->fn);
8436 pedwarn (input_location, 0,
8437 " (you can disable this with "
8438 "%<-fno-deduce-init-list%>)");
8439 }
8440 }
8441
8442 /* Set user_conv_p on the argument conversions, so rvalue/base handling
8443 knows not to allow any more UDCs. This needs to happen after we
8444 process cand->warnings. */
8445 if (flags & LOOKUP_NO_CONVERSION)
8446 conv->user_conv_p = true;
8447
8448 tsubst_flags_t arg_complain = complain;
8449 if (!conversion_warning)
8450 arg_complain &= ~tf_warning;
8451
8452 val = convert_like_with_context (conv, arg, fn, i - is_method,
8453 arg_complain);
8454 val = convert_for_arg_passing (type, val, arg_complain);
8455
8456 if (val == error_mark_node)
8457 return error_mark_node;
8458 else
8459 argarray[j++] = val;
8460 }
8461
8462 /* Default arguments */
8463 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
8464 {
8465 if (TREE_VALUE (parm) == error_mark_node)
8466 return error_mark_node;
8467 val = convert_default_arg (TREE_VALUE (parm),
8468 TREE_PURPOSE (parm),
8469 fn, i - is_method,
8470 complain);
8471 if (val == error_mark_node)
8472 return error_mark_node;
8473 argarray[j++] = val;
8474 }
8475
8476 /* Ellipsis */
8477 int magic = magic_varargs_p (fn);
8478 for (; arg_index < vec_safe_length (args); ++arg_index)
8479 {
8480 tree a = (*args)[arg_index];
8481 if ((magic == 3 && arg_index == 2) || magic == 2)
8482 {
8483 /* Do no conversions for certain magic varargs. */
8484 a = mark_type_use (a);
8485 if (TREE_CODE (a) == FUNCTION_DECL && reject_gcc_builtin (a))
8486 return error_mark_node;
8487 }
8488 else if (magic != 0)
8489 /* For other magic varargs only do decay_conversion. */
8490 a = decay_conversion (a, complain);
8491 else if (DECL_CONSTRUCTOR_P (fn)
8492 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn),
8493 TREE_TYPE (a)))
8494 {
8495 /* Avoid infinite recursion trying to call A(...). */
8496 if (complain & tf_error)
8497 /* Try to call the actual copy constructor for a good error. */
8498 call_copy_ctor (a, complain);
8499 return error_mark_node;
8500 }
8501 else
8502 a = convert_arg_to_ellipsis (a, complain);
8503 if (a == error_mark_node)
8504 return error_mark_node;
8505 argarray[j++] = a;
8506 }
8507
8508 gcc_assert (j <= nargs);
8509 nargs = j;
8510
8511 /* Avoid to do argument-transformation, if warnings for format, and for
8512 nonnull are disabled. Just in case that at least one of them is active
8513 the check_function_arguments function might warn about something. */
8514
8515 bool warned_p = false;
8516 if (warn_nonnull
8517 || warn_format
8518 || warn_suggest_attribute_format
8519 || warn_restrict)
8520 {
8521 tree *fargs = (!nargs ? argarray
8522 : (tree *) alloca (nargs * sizeof (tree)));
8523 for (j = 0; j < nargs; j++)
8524 {
8525 /* For -Wformat undo the implicit passing by hidden reference
8526 done by convert_arg_to_ellipsis. */
8527 if (TREE_CODE (argarray[j]) == ADDR_EXPR
8528 && TYPE_REF_P (TREE_TYPE (argarray[j])))
8529 fargs[j] = TREE_OPERAND (argarray[j], 0);
8530 else
8531 fargs[j] = argarray[j];
8532 }
8533
8534 warned_p = check_function_arguments (input_location, fn, TREE_TYPE (fn),
8535 nargs, fargs, NULL);
8536 }
8537
8538 if (DECL_INHERITED_CTOR (fn))
8539 {
8540 /* Check for passing ellipsis arguments to an inherited constructor. We
8541 could handle this by open-coding the inherited constructor rather than
8542 defining it, but let's not bother now. */
8543 if (!cp_unevaluated_operand
8544 && cand->num_convs
8545 && cand->convs[cand->num_convs-1]->ellipsis_p)
8546 {
8547 if (complain & tf_error)
8548 {
8549 sorry ("passing arguments to ellipsis of inherited constructor "
8550 "%qD", cand->fn);
8551 inform (DECL_SOURCE_LOCATION (cand->fn), "declared here");
8552 }
8553 return error_mark_node;
8554 }
8555
8556 /* A base constructor inheriting from a virtual base doesn't get the
8557 inherited arguments, just this and __vtt. */
8558 if (ctor_omit_inherited_parms (fn))
8559 nargs = 2;
8560 }
8561
8562 /* Avoid actually calling copy constructors and copy assignment operators,
8563 if possible. */
8564
8565 if (! flag_elide_constructors && !force_elide)
8566 /* Do things the hard way. */;
8567 else if (cand->num_convs == 1
8568 && (DECL_COPY_CONSTRUCTOR_P (fn)
8569 || DECL_MOVE_CONSTRUCTOR_P (fn))
8570 /* It's unsafe to elide the constructor when handling
8571 a noexcept-expression, it may evaluate to the wrong
8572 value (c++/53025). */
8573 && (force_elide || cp_noexcept_operand == 0))
8574 {
8575 tree targ;
8576 tree arg = argarray[num_artificial_parms_for (fn)];
8577 tree fa;
8578 bool trivial = trivial_fn_p (fn);
8579
8580 /* Pull out the real argument, disregarding const-correctness. */
8581 targ = arg;
8582 /* Strip the reference binding for the constructor parameter. */
8583 if (CONVERT_EXPR_P (targ)
8584 && TYPE_REF_P (TREE_TYPE (targ)))
8585 targ = TREE_OPERAND (targ, 0);
8586 /* But don't strip any other reference bindings; binding a temporary to a
8587 reference prevents copy elision. */
8588 while ((CONVERT_EXPR_P (targ)
8589 && !TYPE_REF_P (TREE_TYPE (targ)))
8590 || TREE_CODE (targ) == NON_LVALUE_EXPR)
8591 targ = TREE_OPERAND (targ, 0);
8592 if (TREE_CODE (targ) == ADDR_EXPR)
8593 {
8594 targ = TREE_OPERAND (targ, 0);
8595 if (!same_type_ignoring_top_level_qualifiers_p
8596 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
8597 targ = NULL_TREE;
8598 }
8599 else
8600 targ = NULL_TREE;
8601
8602 if (targ)
8603 arg = targ;
8604 else
8605 arg = cp_build_fold_indirect_ref (arg);
8606
8607 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base
8608 subobject. */
8609 if (CHECKING_P && cxx_dialect >= cxx17)
8610 gcc_assert (TREE_CODE (arg) != TARGET_EXPR
8611 || force_elide
8612 /* It's from binding the ref parm to a packed field. */
8613 || convs[0]->need_temporary_p
8614 || seen_error ()
8615 /* See unsafe_copy_elision_p. */
8616 || DECL_BASE_CONSTRUCTOR_P (fn));
8617
8618 fa = argarray[0];
8619 bool unsafe = unsafe_copy_elision_p (fa, arg);
8620 bool eliding_temp = (TREE_CODE (arg) == TARGET_EXPR && !unsafe);
8621
8622 /* [class.copy]: the copy constructor is implicitly defined even if the
8623 implementation elided its use. But don't warn about deprecation when
8624 eliding a temporary, as then no copy is actually performed. */
8625 warning_sentinel s (warn_deprecated_copy, eliding_temp);
8626 if (force_elide)
8627 /* The language says this isn't called. */;
8628 else if (!trivial)
8629 {
8630 if (!mark_used (fn, complain) && !(complain & tf_error))
8631 return error_mark_node;
8632 already_used = true;
8633 }
8634 else
8635 cp_warn_deprecated_use (fn, complain);
8636
8637 /* If we're creating a temp and we already have one, don't create a
8638 new one. If we're not creating a temp but we get one, use
8639 INIT_EXPR to collapse the temp into our target. Otherwise, if the
8640 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
8641 temp or an INIT_EXPR otherwise. */
8642 if (is_dummy_object (fa))
8643 {
8644 if (TREE_CODE (arg) == TARGET_EXPR)
8645 return arg;
8646 else if (trivial)
8647 return force_target_expr (DECL_CONTEXT (fn), arg, complain);
8648 }
8649 else if ((trivial || TREE_CODE (arg) == TARGET_EXPR)
8650 && !unsafe)
8651 {
8652 tree to = cp_stabilize_reference (cp_build_fold_indirect_ref (fa));
8653
8654 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
8655 return val;
8656 }
8657 }
8658 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
8659 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR)
8660 && trivial_fn_p (fn))
8661 {
8662 tree to = cp_stabilize_reference
8663 (cp_build_fold_indirect_ref (argarray[0]));
8664 tree type = TREE_TYPE (to);
8665 tree as_base = CLASSTYPE_AS_BASE (type);
8666 tree arg = argarray[1];
8667 location_t loc = cp_expr_loc_or_loc (arg, input_location);
8668
8669 if (is_really_empty_class (type, /*ignore_vptr*/true))
8670 {
8671 /* Avoid copying empty classes. */
8672 val = build2 (COMPOUND_EXPR, type, arg, to);
8673 TREE_NO_WARNING (val) = 1;
8674 }
8675 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
8676 {
8677 if (is_std_init_list (type)
8678 && conv_binds_ref_to_prvalue (convs[1]))
8679 warning_at (loc, OPT_Winit_list_lifetime,
8680 "assignment from temporary initializer_list does not "
8681 "extend the lifetime of the underlying array");
8682 arg = cp_build_fold_indirect_ref (arg);
8683 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
8684 }
8685 else
8686 {
8687 /* We must only copy the non-tail padding parts. */
8688 tree arg0, arg2, t;
8689 tree array_type, alias_set;
8690
8691 arg2 = TYPE_SIZE_UNIT (as_base);
8692 arg0 = cp_build_addr_expr (to, complain);
8693
8694 array_type = build_array_type (unsigned_char_type_node,
8695 build_index_type
8696 (size_binop (MINUS_EXPR,
8697 arg2, size_int (1))));
8698 alias_set = build_int_cst (build_pointer_type (type), 0);
8699 t = build2 (MODIFY_EXPR, void_type_node,
8700 build2 (MEM_REF, array_type, arg0, alias_set),
8701 build2 (MEM_REF, array_type, arg, alias_set));
8702 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to);
8703 TREE_NO_WARNING (val) = 1;
8704 }
8705
8706 cp_warn_deprecated_use (fn, complain);
8707
8708 return val;
8709 }
8710 else if (trivial_fn_p (fn))
8711 {
8712 if (DECL_DESTRUCTOR_P (fn))
8713 return build_trivial_dtor_call (argarray[0]);
8714 else if (default_ctor_p (fn))
8715 {
8716 if (is_dummy_object (argarray[0]))
8717 return force_target_expr (DECL_CONTEXT (fn), void_node,
8718 no_cleanup_complain);
8719 else
8720 return cp_build_fold_indirect_ref (argarray[0]);
8721 }
8722 }
8723
8724 gcc_assert (!force_elide);
8725
8726 if (!already_used
8727 && !mark_used (fn, complain))
8728 return error_mark_node;
8729
8730 /* Warn if the built-in writes to an object of a non-trivial type. */
8731 if (warn_class_memaccess
8732 && vec_safe_length (args) >= 2
8733 && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8734 maybe_warn_class_memaccess (input_location, fn, args);
8735
8736 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
8737 {
8738 tree t;
8739 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
8740 DECL_CONTEXT (fn),
8741 ba_any, NULL, complain);
8742 gcc_assert (binfo && binfo != error_mark_node);
8743
8744 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1,
8745 complain);
8746 if (TREE_SIDE_EFFECTS (argarray[0]))
8747 argarray[0] = save_expr (argarray[0]);
8748 t = build_pointer_type (TREE_TYPE (fn));
8749 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
8750 TREE_TYPE (fn) = t;
8751 }
8752 else
8753 {
8754 fn = build_addr_func (fn, complain);
8755 if (fn == error_mark_node)
8756 return error_mark_node;
8757 }
8758
8759 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag);
8760 if (call == error_mark_node)
8761 return call;
8762 if (cand->flags & LOOKUP_LIST_INIT_CTOR)
8763 {
8764 tree c = extract_call_expr (call);
8765 /* build_new_op_1 will clear this when appropriate. */
8766 CALL_EXPR_ORDERED_ARGS (c) = true;
8767 }
8768 if (warned_p)
8769 {
8770 tree c = extract_call_expr (call);
8771 if (TREE_CODE (c) == CALL_EXPR)
8772 TREE_NO_WARNING (c) = 1;
8773 }
8774 return call;
8775 }
8776
8777 namespace
8778 {
8779
8780 /* Return the DECL of the first non-static subobject of class TYPE
8781 that satisfies the predicate PRED or null if none can be found. */
8782
8783 template <class Predicate>
8784 tree
first_non_static_field(tree type,Predicate pred)8785 first_non_static_field (tree type, Predicate pred)
8786 {
8787 if (!type || !CLASS_TYPE_P (type))
8788 return NULL_TREE;
8789
8790 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
8791 {
8792 if (TREE_CODE (field) != FIELD_DECL)
8793 continue;
8794 if (TREE_STATIC (field))
8795 continue;
8796 if (pred (field))
8797 return field;
8798 }
8799
8800 int i = 0;
8801
8802 for (tree base_binfo, binfo = TYPE_BINFO (type);
8803 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
8804 {
8805 tree base = TREE_TYPE (base_binfo);
8806 if (pred (base))
8807 return base;
8808 if (tree field = first_non_static_field (base, pred))
8809 return field;
8810 }
8811
8812 return NULL_TREE;
8813 }
8814
8815 struct NonPublicField
8816 {
operatorNonPublicField8817 bool operator() (const_tree t)
8818 {
8819 return DECL_P (t) && (TREE_PRIVATE (t) || TREE_PROTECTED (t));
8820 }
8821 };
8822
8823 /* Return the DECL of the first non-public subobject of class TYPE
8824 or null if none can be found. */
8825
8826 static inline tree
first_non_public_field(tree type)8827 first_non_public_field (tree type)
8828 {
8829 return first_non_static_field (type, NonPublicField ());
8830 }
8831
8832 struct NonTrivialField
8833 {
operatorNonTrivialField8834 bool operator() (const_tree t)
8835 {
8836 return !trivial_type_p (DECL_P (t) ? TREE_TYPE (t) : t);
8837 }
8838 };
8839
8840 /* Return the DECL of the first non-trivial subobject of class TYPE
8841 or null if none can be found. */
8842
8843 static inline tree
first_non_trivial_field(tree type)8844 first_non_trivial_field (tree type)
8845 {
8846 return first_non_static_field (type, NonTrivialField ());
8847 }
8848
8849 } /* unnamed namespace */
8850
8851 /* Return true if all copy and move assignment operator overloads for
8852 class TYPE are trivial and at least one of them is not deleted and,
8853 when ACCESS is set, accessible. Return false otherwise. Set
8854 HASASSIGN to true when the TYPE has a (not necessarily trivial)
8855 copy or move assignment. */
8856
8857 static bool
has_trivial_copy_assign_p(tree type,bool access,bool * hasassign)8858 has_trivial_copy_assign_p (tree type, bool access, bool *hasassign)
8859 {
8860 tree fns = get_class_binding (type, assign_op_identifier);
8861 bool all_trivial = true;
8862
8863 /* Iterate over overloads of the assignment operator, checking
8864 accessible copy assignments for triviality. */
8865
8866 for (ovl_iterator oi (fns); oi; ++oi)
8867 {
8868 tree f = *oi;
8869
8870 /* Skip operators that aren't copy assignments. */
8871 if (!copy_fn_p (f))
8872 continue;
8873
8874 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f))
8875 || accessible_p (TYPE_BINFO (type), f, true));
8876
8877 /* Skip template assignment operators and deleted functions. */
8878 if (TREE_CODE (f) != FUNCTION_DECL || DECL_DELETED_FN (f))
8879 continue;
8880
8881 if (accessible)
8882 *hasassign = true;
8883
8884 if (!accessible || !trivial_fn_p (f))
8885 all_trivial = false;
8886
8887 /* Break early when both properties have been determined. */
8888 if (*hasassign && !all_trivial)
8889 break;
8890 }
8891
8892 /* Return true if they're all trivial and one of the expressions
8893 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */
8894 tree ref = cp_build_reference_type (type, false);
8895 return (all_trivial
8896 && (is_trivially_xible (MODIFY_EXPR, type, type)
8897 || is_trivially_xible (MODIFY_EXPR, type, ref)));
8898 }
8899
8900 /* Return true if all copy and move ctor overloads for class TYPE are
8901 trivial and at least one of them is not deleted and, when ACCESS is
8902 set, accessible. Return false otherwise. Set each element of HASCTOR[]
8903 to true when the TYPE has a (not necessarily trivial) default and copy
8904 (or move) ctor, respectively. */
8905
8906 static bool
has_trivial_copy_p(tree type,bool access,bool hasctor[2])8907 has_trivial_copy_p (tree type, bool access, bool hasctor[2])
8908 {
8909 tree fns = get_class_binding (type, complete_ctor_identifier);
8910 bool all_trivial = true;
8911
8912 for (ovl_iterator oi (fns); oi; ++oi)
8913 {
8914 tree f = *oi;
8915
8916 /* Skip template constructors. */
8917 if (TREE_CODE (f) != FUNCTION_DECL)
8918 continue;
8919
8920 bool cpy_or_move_ctor_p = copy_fn_p (f);
8921
8922 /* Skip ctors other than default, copy, and move. */
8923 if (!cpy_or_move_ctor_p && !default_ctor_p (f))
8924 continue;
8925
8926 if (DECL_DELETED_FN (f))
8927 continue;
8928
8929 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f))
8930 || accessible_p (TYPE_BINFO (type), f, true));
8931
8932 if (accessible)
8933 hasctor[cpy_or_move_ctor_p] = true;
8934
8935 if (cpy_or_move_ctor_p && (!accessible || !trivial_fn_p (f)))
8936 all_trivial = false;
8937
8938 /* Break early when both properties have been determined. */
8939 if (hasctor[0] && hasctor[1] && !all_trivial)
8940 break;
8941 }
8942
8943 return all_trivial;
8944 }
8945
8946 /* Issue a warning on a call to the built-in function FNDECL if it is
8947 a raw memory write whose destination is not an object of (something
8948 like) trivial or standard layout type with a non-deleted assignment
8949 and copy ctor. Detects const correctness violations, corrupting
8950 references, virtual table pointers, and bypassing non-trivial
8951 assignments. */
8952
8953 static void
maybe_warn_class_memaccess(location_t loc,tree fndecl,const vec<tree,va_gc> * args)8954 maybe_warn_class_memaccess (location_t loc, tree fndecl,
8955 const vec<tree, va_gc> *args)
8956 {
8957 /* Except for bcopy where it's second, the destination pointer is
8958 the first argument for all functions handled here. Compute
8959 the index of the destination and source arguments. */
8960 unsigned dstidx = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_BCOPY;
8961 unsigned srcidx = !dstidx;
8962
8963 tree dest = (*args)[dstidx];
8964 if (!TREE_TYPE (dest) || !INDIRECT_TYPE_P (TREE_TYPE (dest)))
8965 return;
8966
8967 tree srctype = NULL_TREE;
8968
8969 /* Determine the type of the pointed-to object and whether it's
8970 a complete class type. */
8971 tree desttype = TREE_TYPE (TREE_TYPE (dest));
8972
8973 if (!desttype || !COMPLETE_TYPE_P (desttype) || !CLASS_TYPE_P (desttype))
8974 return;
8975
8976 /* Check to see if the raw memory call is made by a non-static member
8977 function with THIS as the destination argument for the destination
8978 type. If so, and if the class has no non-trivial bases or members,
8979 be more permissive. */
8980 if (current_function_decl
8981 && DECL_NONSTATIC_MEMBER_FUNCTION_P (current_function_decl)
8982 && is_this_parameter (tree_strip_nop_conversions (dest)))
8983 {
8984 tree ctx = DECL_CONTEXT (current_function_decl);
8985 bool special = same_type_ignoring_top_level_qualifiers_p (ctx, desttype);
8986 tree binfo = TYPE_BINFO (ctx);
8987
8988 if (special
8989 && !BINFO_VTABLE (binfo)
8990 && !first_non_trivial_field (desttype))
8991 return;
8992 }
8993
8994 /* True if the class is trivial. */
8995 bool trivial = trivial_type_p (desttype);
8996
8997 /* Set to true if DESTYPE has an accessible copy assignment. */
8998 bool hasassign = false;
8999 /* True if all of the class' overloaded copy assignment operators
9000 are all trivial (and not deleted) and at least one of them is
9001 accessible. */
9002 bool trivassign = has_trivial_copy_assign_p (desttype, true, &hasassign);
9003
9004 /* Set to true if DESTTYPE has an accessible default and copy ctor,
9005 respectively. */
9006 bool hasctors[2] = { false, false };
9007
9008 /* True if all of the class' overloaded copy constructors are all
9009 trivial (and not deleted) and at least one of them is accessible. */
9010 bool trivcopy = has_trivial_copy_p (desttype, true, hasctors);
9011
9012 /* Set FLD to the first private/protected member of the class. */
9013 tree fld = trivial ? first_non_public_field (desttype) : NULL_TREE;
9014
9015 /* The warning format string. */
9016 const char *warnfmt = NULL;
9017 /* A suggested alternative to offer instead of the raw memory call.
9018 Empty string when none can be come up with. */
9019 const char *suggest = "";
9020 bool warned = false;
9021
9022 switch (DECL_FUNCTION_CODE (fndecl))
9023 {
9024 case BUILT_IN_MEMSET:
9025 if (!integer_zerop (maybe_constant_value ((*args)[1])))
9026 {
9027 /* Diagnose setting non-copy-assignable or non-trivial types,
9028 or types with a private member, to (potentially) non-zero
9029 bytes. Since the value of the bytes being written is unknown,
9030 suggest using assignment instead (if one exists). Also warn
9031 for writes into objects for which zero-initialization doesn't
9032 mean all bits clear (pointer-to-member data, where null is all
9033 bits set). Since the value being written is (most likely)
9034 non-zero, simply suggest assignment (but not copy assignment). */
9035 suggest = "; use assignment instead";
9036 if (!trivassign)
9037 warnfmt = G_("%qD writing to an object of type %#qT with "
9038 "no trivial copy-assignment");
9039 else if (!trivial)
9040 warnfmt = G_("%qD writing to an object of non-trivial type %#qT%s");
9041 else if (fld)
9042 {
9043 const char *access = TREE_PRIVATE (fld) ? "private" : "protected";
9044 warned = warning_at (loc, OPT_Wclass_memaccess,
9045 "%qD writing to an object of type %#qT with "
9046 "%qs member %qD",
9047 fndecl, desttype, access, fld);
9048 }
9049 else if (!zero_init_p (desttype))
9050 warnfmt = G_("%qD writing to an object of type %#qT containing "
9051 "a pointer to data member%s");
9052
9053 break;
9054 }
9055 /* Fall through. */
9056
9057 case BUILT_IN_BZERO:
9058 /* Similarly to the above, diagnose clearing non-trivial or non-
9059 standard layout objects, or objects of types with no assignmenmt.
9060 Since the value being written is known to be zero, suggest either
9061 copy assignment, copy ctor, or default ctor as an alternative,
9062 depending on what's available. */
9063
9064 if (hasassign && hasctors[0])
9065 suggest = G_("; use assignment or value-initialization instead");
9066 else if (hasassign)
9067 suggest = G_("; use assignment instead");
9068 else if (hasctors[0])
9069 suggest = G_("; use value-initialization instead");
9070
9071 if (!trivassign)
9072 warnfmt = G_("%qD clearing an object of type %#qT with "
9073 "no trivial copy-assignment%s");
9074 else if (!trivial)
9075 warnfmt = G_("%qD clearing an object of non-trivial type %#qT%s");
9076 else if (!zero_init_p (desttype))
9077 warnfmt = G_("%qD clearing an object of type %#qT containing "
9078 "a pointer-to-member%s");
9079 break;
9080
9081 case BUILT_IN_BCOPY:
9082 case BUILT_IN_MEMCPY:
9083 case BUILT_IN_MEMMOVE:
9084 case BUILT_IN_MEMPCPY:
9085 /* Determine the type of the source object. */
9086 srctype = TREE_TYPE ((*args)[srcidx]);
9087 if (!srctype || !INDIRECT_TYPE_P (srctype))
9088 srctype = void_type_node;
9089 else
9090 srctype = TREE_TYPE (srctype);
9091
9092 /* Since it's impossible to determine wheter the byte copy is
9093 being used in place of assignment to an existing object or
9094 as a substitute for initialization, assume it's the former.
9095 Determine the best alternative to use instead depending on
9096 what's not deleted. */
9097 if (hasassign && hasctors[1])
9098 suggest = G_("; use copy-assignment or copy-initialization instead");
9099 else if (hasassign)
9100 suggest = G_("; use copy-assignment instead");
9101 else if (hasctors[1])
9102 suggest = G_("; use copy-initialization instead");
9103
9104 if (!trivassign)
9105 warnfmt = G_("%qD writing to an object of type %#qT with no trivial "
9106 "copy-assignment%s");
9107 else if (!trivially_copyable_p (desttype))
9108 warnfmt = G_("%qD writing to an object of non-trivially copyable "
9109 "type %#qT%s");
9110 else if (!trivcopy)
9111 warnfmt = G_("%qD writing to an object with a deleted copy constructor");
9112
9113 else if (!trivial
9114 && !VOID_TYPE_P (srctype)
9115 && !char_type_p (TYPE_MAIN_VARIANT (srctype))
9116 && !same_type_ignoring_top_level_qualifiers_p (desttype,
9117 srctype))
9118 {
9119 /* Warn when copying into a non-trivial object from an object
9120 of a different type other than void or char. */
9121 warned = warning_at (loc, OPT_Wclass_memaccess,
9122 "%qD copying an object of non-trivial type "
9123 "%#qT from an array of %#qT",
9124 fndecl, desttype, srctype);
9125 }
9126 else if (fld
9127 && !VOID_TYPE_P (srctype)
9128 && !char_type_p (TYPE_MAIN_VARIANT (srctype))
9129 && !same_type_ignoring_top_level_qualifiers_p (desttype,
9130 srctype))
9131 {
9132 const char *access = TREE_PRIVATE (fld) ? "private" : "protected";
9133 warned = warning_at (loc, OPT_Wclass_memaccess,
9134 "%qD copying an object of type %#qT with "
9135 "%qs member %qD from an array of %#qT; use "
9136 "assignment or copy-initialization instead",
9137 fndecl, desttype, access, fld, srctype);
9138 }
9139 else if (!trivial && vec_safe_length (args) > 2)
9140 {
9141 tree sz = maybe_constant_value ((*args)[2]);
9142 if (!tree_fits_uhwi_p (sz))
9143 break;
9144
9145 /* Finally, warn on partial copies. */
9146 unsigned HOST_WIDE_INT typesize
9147 = tree_to_uhwi (TYPE_SIZE_UNIT (desttype));
9148 if (unsigned HOST_WIDE_INT partial = tree_to_uhwi (sz) % typesize)
9149 warned = warning_at (loc, OPT_Wclass_memaccess,
9150 (typesize - partial > 1
9151 ? G_("%qD writing to an object of "
9152 "a non-trivial type %#qT leaves %wu "
9153 "bytes unchanged")
9154 : G_("%qD writing to an object of "
9155 "a non-trivial type %#qT leaves %wu "
9156 "byte unchanged")),
9157 fndecl, desttype, typesize - partial);
9158 }
9159 break;
9160
9161 case BUILT_IN_REALLOC:
9162
9163 if (!trivially_copyable_p (desttype))
9164 warnfmt = G_("%qD moving an object of non-trivially copyable type "
9165 "%#qT; use %<new%> and %<delete%> instead");
9166 else if (!trivcopy)
9167 warnfmt = G_("%qD moving an object of type %#qT with deleted copy "
9168 "constructor; use %<new%> and %<delete%> instead");
9169 else if (!get_dtor (desttype, tf_none))
9170 warnfmt = G_("%qD moving an object of type %#qT with deleted "
9171 "destructor");
9172 else if (!trivial)
9173 {
9174 tree sz = maybe_constant_value ((*args)[1]);
9175 if (TREE_CODE (sz) == INTEGER_CST
9176 && tree_int_cst_lt (sz, TYPE_SIZE_UNIT (desttype)))
9177 /* Finally, warn on reallocation into insufficient space. */
9178 warned = warning_at (loc, OPT_Wclass_memaccess,
9179 "%qD moving an object of non-trivial type "
9180 "%#qT and size %E into a region of size %E",
9181 fndecl, desttype, TYPE_SIZE_UNIT (desttype),
9182 sz);
9183 }
9184 break;
9185
9186 default:
9187 return;
9188 }
9189
9190 if (warnfmt)
9191 {
9192 if (suggest)
9193 warned = warning_at (loc, OPT_Wclass_memaccess,
9194 warnfmt, fndecl, desttype, suggest);
9195 else
9196 warned = warning_at (loc, OPT_Wclass_memaccess,
9197 warnfmt, fndecl, desttype);
9198 }
9199
9200 if (warned)
9201 inform (location_of (desttype), "%#qT declared here", desttype);
9202 }
9203
9204 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
9205 This function performs no overload resolution, conversion, or other
9206 high-level operations. */
9207
9208 tree
build_cxx_call(tree fn,int nargs,tree * argarray,tsubst_flags_t complain)9209 build_cxx_call (tree fn, int nargs, tree *argarray,
9210 tsubst_flags_t complain)
9211 {
9212 tree fndecl;
9213
9214 /* Remember roughly where this call is. */
9215 location_t loc = cp_expr_loc_or_loc (fn, input_location);
9216 fn = build_call_a (fn, nargs, argarray);
9217 SET_EXPR_LOCATION (fn, loc);
9218
9219 fndecl = get_callee_fndecl (fn);
9220
9221 /* Check that arguments to builtin functions match the expectations. */
9222 if (fndecl
9223 && !processing_template_decl
9224 && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
9225 {
9226 int i;
9227
9228 /* We need to take care that values to BUILT_IN_NORMAL
9229 are reduced. */
9230 for (i = 0; i < nargs; i++)
9231 argarray[i] = maybe_constant_value (argarray[i]);
9232
9233 if (!check_builtin_function_arguments (EXPR_LOCATION (fn), vNULL, fndecl,
9234 nargs, argarray))
9235 return error_mark_node;
9236 }
9237
9238 if (VOID_TYPE_P (TREE_TYPE (fn)))
9239 return fn;
9240
9241 /* 5.2.2/11: If a function call is a prvalue of object type: if the
9242 function call is either the operand of a decltype-specifier or the
9243 right operand of a comma operator that is the operand of a
9244 decltype-specifier, a temporary object is not introduced for the
9245 prvalue. The type of the prvalue may be incomplete. */
9246 if (!(complain & tf_decltype))
9247 {
9248 fn = require_complete_type_sfinae (fn, complain);
9249 if (fn == error_mark_node)
9250 return error_mark_node;
9251
9252 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
9253 {
9254 fn = build_cplus_new (TREE_TYPE (fn), fn, complain);
9255 maybe_warn_parm_abi (TREE_TYPE (fn), loc);
9256 }
9257 }
9258 return convert_from_reference (fn);
9259 }
9260
9261 /* Returns the value to use for the in-charge parameter when making a
9262 call to a function with the indicated NAME.
9263
9264 FIXME:Can't we find a neater way to do this mapping? */
9265
9266 tree
in_charge_arg_for_name(tree name)9267 in_charge_arg_for_name (tree name)
9268 {
9269 if (IDENTIFIER_CTOR_P (name))
9270 {
9271 if (name == complete_ctor_identifier)
9272 return integer_one_node;
9273 gcc_checking_assert (name == base_ctor_identifier);
9274 }
9275 else
9276 {
9277 if (name == complete_dtor_identifier)
9278 return integer_two_node;
9279 else if (name == deleting_dtor_identifier)
9280 return integer_three_node;
9281 gcc_checking_assert (name == base_dtor_identifier);
9282 }
9283
9284 return integer_zero_node;
9285 }
9286
9287 /* We've built up a constructor call RET. Complain if it delegates to the
9288 constructor we're currently compiling. */
9289
9290 static void
check_self_delegation(tree ret)9291 check_self_delegation (tree ret)
9292 {
9293 if (TREE_CODE (ret) == TARGET_EXPR)
9294 ret = TARGET_EXPR_INITIAL (ret);
9295 tree fn = cp_get_callee_fndecl_nofold (ret);
9296 if (fn && DECL_ABSTRACT_ORIGIN (fn) == current_function_decl)
9297 error ("constructor delegates to itself");
9298 }
9299
9300 /* Build a call to a constructor, destructor, or an assignment
9301 operator for INSTANCE, an expression with class type. NAME
9302 indicates the special member function to call; *ARGS are the
9303 arguments. ARGS may be NULL. This may change ARGS. BINFO
9304 indicates the base of INSTANCE that is to be passed as the `this'
9305 parameter to the member function called.
9306
9307 FLAGS are the LOOKUP_* flags to use when processing the call.
9308
9309 If NAME indicates a complete object constructor, INSTANCE may be
9310 NULL_TREE. In this case, the caller will call build_cplus_new to
9311 store the newly constructed object into a VAR_DECL. */
9312
9313 tree
build_special_member_call(tree instance,tree name,vec<tree,va_gc> ** args,tree binfo,int flags,tsubst_flags_t complain)9314 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args,
9315 tree binfo, int flags, tsubst_flags_t complain)
9316 {
9317 tree fns;
9318 /* The type of the subobject to be constructed or destroyed. */
9319 tree class_type;
9320 vec<tree, va_gc> *allocated = NULL;
9321 tree ret;
9322
9323 gcc_assert (IDENTIFIER_CDTOR_P (name) || name == assign_op_identifier);
9324
9325 if (error_operand_p (instance))
9326 return error_mark_node;
9327
9328 if (IDENTIFIER_DTOR_P (name))
9329 {
9330 gcc_assert (args == NULL || vec_safe_is_empty (*args));
9331 if (!type_build_dtor_call (TREE_TYPE (instance)))
9332 /* Shortcut to avoid lazy destructor declaration. */
9333 return build_trivial_dtor_call (instance);
9334 }
9335
9336 if (TYPE_P (binfo))
9337 {
9338 /* Resolve the name. */
9339 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
9340 return error_mark_node;
9341
9342 binfo = TYPE_BINFO (binfo);
9343 }
9344
9345 gcc_assert (binfo != NULL_TREE);
9346
9347 class_type = BINFO_TYPE (binfo);
9348
9349 /* Handle the special case where INSTANCE is NULL_TREE. */
9350 if (name == complete_ctor_identifier && !instance)
9351 instance = build_dummy_object (class_type);
9352 else
9353 {
9354 /* Convert to the base class, if necessary. */
9355 if (!same_type_ignoring_top_level_qualifiers_p
9356 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
9357 {
9358 if (IDENTIFIER_CDTOR_P (name))
9359 /* For constructors and destructors, either the base is
9360 non-virtual, or it is virtual but we are doing the
9361 conversion from a constructor or destructor for the
9362 complete object. In either case, we can convert
9363 statically. */
9364 instance = convert_to_base_statically (instance, binfo);
9365 else
9366 {
9367 /* However, for assignment operators, we must convert
9368 dynamically if the base is virtual. */
9369 gcc_checking_assert (name == assign_op_identifier);
9370 instance = build_base_path (PLUS_EXPR, instance,
9371 binfo, /*nonnull=*/1, complain);
9372 }
9373 }
9374 }
9375
9376 gcc_assert (instance != NULL_TREE);
9377
9378 /* In C++17, "If the initializer expression is a prvalue and the
9379 cv-unqualified version of the source type is the same class as the class
9380 of the destination, the initializer expression is used to initialize the
9381 destination object." Handle that here to avoid doing overload
9382 resolution. */
9383 if (cxx_dialect >= cxx17
9384 && args && vec_safe_length (*args) == 1
9385 && name == complete_ctor_identifier)
9386 {
9387 tree arg = (**args)[0];
9388
9389 if (BRACE_ENCLOSED_INITIALIZER_P (arg)
9390 && !TYPE_HAS_LIST_CTOR (class_type)
9391 && CONSTRUCTOR_NELTS (arg) == 1)
9392 arg = CONSTRUCTOR_ELT (arg, 0)->value;
9393
9394 if ((TREE_CODE (arg) == TARGET_EXPR
9395 || TREE_CODE (arg) == CONSTRUCTOR)
9396 && (same_type_ignoring_top_level_qualifiers_p
9397 (class_type, TREE_TYPE (arg))))
9398 {
9399 if (is_dummy_object (instance))
9400 return arg;
9401 else if (TREE_CODE (arg) == TARGET_EXPR)
9402 TARGET_EXPR_DIRECT_INIT_P (arg) = true;
9403
9404 if ((complain & tf_error)
9405 && (flags & LOOKUP_DELEGATING_CONS))
9406 check_self_delegation (arg);
9407 /* Avoid change of behavior on Wunused-var-2.C. */
9408 instance = mark_lvalue_use (instance);
9409 return build2 (INIT_EXPR, class_type, instance, arg);
9410 }
9411 }
9412
9413 fns = lookup_fnfields (binfo, name, 1);
9414
9415 /* When making a call to a constructor or destructor for a subobject
9416 that uses virtual base classes, pass down a pointer to a VTT for
9417 the subobject. */
9418 if ((name == base_ctor_identifier
9419 || name == base_dtor_identifier)
9420 && CLASSTYPE_VBASECLASSES (class_type))
9421 {
9422 tree vtt;
9423 tree sub_vtt;
9424
9425 /* If the current function is a complete object constructor
9426 or destructor, then we fetch the VTT directly.
9427 Otherwise, we look it up using the VTT we were given. */
9428 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
9429 vtt = decay_conversion (vtt, complain);
9430 if (vtt == error_mark_node)
9431 return error_mark_node;
9432 vtt = build_if_in_charge (vtt, current_vtt_parm);
9433 if (BINFO_SUBVTT_INDEX (binfo))
9434 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo));
9435 else
9436 sub_vtt = vtt;
9437
9438 if (args == NULL)
9439 {
9440 allocated = make_tree_vector ();
9441 args = &allocated;
9442 }
9443
9444 vec_safe_insert (*args, 0, sub_vtt);
9445 }
9446
9447 ret = build_new_method_call (instance, fns, args,
9448 TYPE_BINFO (BINFO_TYPE (binfo)),
9449 flags, /*fn=*/NULL,
9450 complain);
9451
9452 if (allocated != NULL)
9453 release_tree_vector (allocated);
9454
9455 if ((complain & tf_error)
9456 && (flags & LOOKUP_DELEGATING_CONS)
9457 && name == complete_ctor_identifier)
9458 check_self_delegation (ret);
9459
9460 return ret;
9461 }
9462
9463 /* Return the NAME, as a C string. The NAME indicates a function that
9464 is a member of TYPE. *FREE_P is set to true if the caller must
9465 free the memory returned.
9466
9467 Rather than go through all of this, we should simply set the names
9468 of constructors and destructors appropriately, and dispense with
9469 ctor_identifier, dtor_identifier, etc. */
9470
9471 static char *
name_as_c_string(tree name,tree type,bool * free_p)9472 name_as_c_string (tree name, tree type, bool *free_p)
9473 {
9474 const char *pretty_name;
9475
9476 /* Assume that we will not allocate memory. */
9477 *free_p = false;
9478 /* Constructors and destructors are special. */
9479 if (IDENTIFIER_CDTOR_P (name))
9480 {
9481 pretty_name
9482 = identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)));
9483 /* For a destructor, add the '~'. */
9484 if (IDENTIFIER_DTOR_P (name))
9485 {
9486 pretty_name = concat ("~", pretty_name, NULL);
9487 /* Remember that we need to free the memory allocated. */
9488 *free_p = true;
9489 }
9490 }
9491 else if (IDENTIFIER_CONV_OP_P (name))
9492 {
9493 pretty_name = concat ("operator ",
9494 type_as_string_translate (TREE_TYPE (name),
9495 TFF_PLAIN_IDENTIFIER),
9496 NULL);
9497 /* Remember that we need to free the memory allocated. */
9498 *free_p = true;
9499 }
9500 else
9501 pretty_name = identifier_to_locale (IDENTIFIER_POINTER (name));
9502
9503 return CONST_CAST (char *, pretty_name);
9504 }
9505
9506 /* If CANDIDATES contains exactly one candidate, return it, otherwise
9507 return NULL. */
9508
9509 static z_candidate *
single_z_candidate(z_candidate * candidates)9510 single_z_candidate (z_candidate *candidates)
9511 {
9512 if (candidates == NULL)
9513 return NULL;
9514
9515 if (candidates->next)
9516 return NULL;
9517
9518 return candidates;
9519 }
9520
9521 /* If CANDIDATE is invalid due to a bad argument type, return the
9522 pertinent conversion_info.
9523
9524 Otherwise, return NULL. */
9525
9526 static const conversion_info *
maybe_get_bad_conversion_for_unmatched_call(const z_candidate * candidate)9527 maybe_get_bad_conversion_for_unmatched_call (const z_candidate *candidate)
9528 {
9529 /* Must be an rr_arg_conversion or rr_bad_arg_conversion. */
9530 rejection_reason *r = candidate->reason;
9531
9532 if (r == NULL)
9533 return NULL;
9534
9535 switch (r->code)
9536 {
9537 default:
9538 return NULL;
9539
9540 case rr_arg_conversion:
9541 return &r->u.conversion;
9542
9543 case rr_bad_arg_conversion:
9544 return &r->u.bad_conversion;
9545 }
9546 }
9547
9548 /* Issue an error and note complaining about a bad argument type at a
9549 callsite with a single candidate FNDECL.
9550
9551 ARG_LOC is the location of the argument (or UNKNOWN_LOCATION, in which
9552 case input_location is used).
9553 FROM_TYPE is the type of the actual argument; TO_TYPE is the type of
9554 the formal parameter. */
9555
9556 void
complain_about_bad_argument(location_t arg_loc,tree from_type,tree to_type,tree fndecl,int parmnum)9557 complain_about_bad_argument (location_t arg_loc,
9558 tree from_type, tree to_type,
9559 tree fndecl, int parmnum)
9560 {
9561 auto_diagnostic_group d;
9562 range_label_for_type_mismatch rhs_label (from_type, to_type);
9563 range_label *label = &rhs_label;
9564 if (arg_loc == UNKNOWN_LOCATION)
9565 {
9566 arg_loc = input_location;
9567 label = NULL;
9568 }
9569 gcc_rich_location richloc (arg_loc, label);
9570 error_at (&richloc,
9571 "cannot convert %qH to %qI",
9572 from_type, to_type);
9573 maybe_inform_about_fndecl_for_bogus_argument_init (fndecl,
9574 parmnum);
9575 }
9576
9577 /* Subroutine of build_new_method_call_1, for where there are no viable
9578 candidates for the call. */
9579
9580 static void
complain_about_no_candidates_for_method_call(tree instance,z_candidate * candidates,tree explicit_targs,tree basetype,tree optype,tree name,bool skip_first_for_error,vec<tree,va_gc> * user_args)9581 complain_about_no_candidates_for_method_call (tree instance,
9582 z_candidate *candidates,
9583 tree explicit_targs,
9584 tree basetype,
9585 tree optype, tree name,
9586 bool skip_first_for_error,
9587 vec<tree, va_gc> *user_args)
9588 {
9589 auto_diagnostic_group d;
9590 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
9591 cxx_incomplete_type_error (instance, basetype);
9592 else if (optype)
9593 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
9594 basetype, optype, build_tree_list_vec (user_args),
9595 TREE_TYPE (instance));
9596 else
9597 {
9598 /* Special-case for when there's a single candidate that's failing
9599 due to a bad argument type. */
9600 if (z_candidate *candidate = single_z_candidate (candidates))
9601 if (const conversion_info *conv
9602 = maybe_get_bad_conversion_for_unmatched_call (candidate))
9603 {
9604 tree from_type = conv->from;
9605 if (!TYPE_P (conv->from))
9606 from_type = lvalue_type (conv->from);
9607 complain_about_bad_argument (conv->loc,
9608 from_type, conv->to_type,
9609 candidate->fn, conv->n_arg);
9610 return;
9611 }
9612
9613 tree arglist = build_tree_list_vec (user_args);
9614 tree errname = name;
9615 bool twiddle = false;
9616 if (IDENTIFIER_CDTOR_P (errname))
9617 {
9618 twiddle = IDENTIFIER_DTOR_P (errname);
9619 errname = constructor_name (basetype);
9620 }
9621 if (explicit_targs)
9622 errname = lookup_template_function (errname, explicit_targs);
9623 if (skip_first_for_error)
9624 arglist = TREE_CHAIN (arglist);
9625 error ("no matching function for call to %<%T::%s%E(%A)%#V%>",
9626 basetype, &"~"[!twiddle], errname, arglist,
9627 TREE_TYPE (instance));
9628 }
9629 print_z_candidates (location_of (name), candidates);
9630 }
9631
9632 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
9633 be set, upon return, to the function called. ARGS may be NULL.
9634 This may change ARGS. */
9635
9636 static tree
build_new_method_call_1(tree instance,tree fns,vec<tree,va_gc> ** args,tree conversion_path,int flags,tree * fn_p,tsubst_flags_t complain)9637 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args,
9638 tree conversion_path, int flags,
9639 tree *fn_p, tsubst_flags_t complain)
9640 {
9641 struct z_candidate *candidates = 0, *cand;
9642 tree explicit_targs = NULL_TREE;
9643 tree basetype = NULL_TREE;
9644 tree access_binfo, binfo;
9645 tree optype;
9646 tree first_mem_arg = NULL_TREE;
9647 tree name;
9648 bool skip_first_for_error;
9649 vec<tree, va_gc> *user_args;
9650 tree call;
9651 tree fn;
9652 int template_only = 0;
9653 bool any_viable_p;
9654 tree orig_instance;
9655 tree orig_fns;
9656 vec<tree, va_gc> *orig_args = NULL;
9657 void *p;
9658
9659 gcc_assert (instance != NULL_TREE);
9660
9661 /* We don't know what function we're going to call, yet. */
9662 if (fn_p)
9663 *fn_p = NULL_TREE;
9664
9665 if (error_operand_p (instance)
9666 || !fns || error_operand_p (fns))
9667 return error_mark_node;
9668
9669 if (!BASELINK_P (fns))
9670 {
9671 if (complain & tf_error)
9672 error ("call to non-function %qD", fns);
9673 return error_mark_node;
9674 }
9675
9676 orig_instance = instance;
9677 orig_fns = fns;
9678
9679 /* Dismantle the baselink to collect all the information we need. */
9680 if (!conversion_path)
9681 conversion_path = BASELINK_BINFO (fns);
9682 access_binfo = BASELINK_ACCESS_BINFO (fns);
9683 binfo = BASELINK_BINFO (fns);
9684 optype = BASELINK_OPTYPE (fns);
9685 fns = BASELINK_FUNCTIONS (fns);
9686 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
9687 {
9688 explicit_targs = TREE_OPERAND (fns, 1);
9689 fns = TREE_OPERAND (fns, 0);
9690 template_only = 1;
9691 }
9692 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
9693 || TREE_CODE (fns) == TEMPLATE_DECL
9694 || TREE_CODE (fns) == OVERLOAD);
9695 fn = OVL_FIRST (fns);
9696 name = DECL_NAME (fn);
9697
9698 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
9699 gcc_assert (CLASS_TYPE_P (basetype));
9700
9701 user_args = args == NULL ? NULL : *args;
9702 /* Under DR 147 A::A() is an invalid constructor call,
9703 not a functional cast. */
9704 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
9705 {
9706 if (! (complain & tf_error))
9707 return error_mark_node;
9708
9709 basetype = DECL_CONTEXT (fn);
9710 name = constructor_name (basetype);
9711 auto_diagnostic_group d;
9712 if (permerror (input_location,
9713 "cannot call constructor %<%T::%D%> directly",
9714 basetype, name))
9715 inform (input_location, "for a function-style cast, remove the "
9716 "redundant %<::%D%>", name);
9717 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
9718 complain);
9719 return call;
9720 }
9721
9722 if (processing_template_decl)
9723 {
9724 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
9725 instance = build_non_dependent_expr (instance);
9726 if (args != NULL)
9727 make_args_non_dependent (*args);
9728 }
9729
9730 /* Process the argument list. */
9731 if (args != NULL && *args != NULL)
9732 {
9733 *args = resolve_args (*args, complain);
9734 if (*args == NULL)
9735 return error_mark_node;
9736 user_args = *args;
9737 }
9738
9739 /* Consider the object argument to be used even if we end up selecting a
9740 static member function. */
9741 instance = mark_type_use (instance);
9742
9743 /* Figure out whether to skip the first argument for the error
9744 message we will display to users if an error occurs. We don't
9745 want to display any compiler-generated arguments. The "this"
9746 pointer hasn't been added yet. However, we must remove the VTT
9747 pointer if this is a call to a base-class constructor or
9748 destructor. */
9749 skip_first_for_error = false;
9750 if (IDENTIFIER_CDTOR_P (name))
9751 {
9752 /* Callers should explicitly indicate whether they want to ctor
9753 the complete object or just the part without virtual bases. */
9754 gcc_assert (name != ctor_identifier);
9755
9756 /* Remove the VTT pointer, if present. */
9757 if ((name == base_ctor_identifier || name == base_dtor_identifier)
9758 && CLASSTYPE_VBASECLASSES (basetype))
9759 skip_first_for_error = true;
9760
9761 /* It's OK to call destructors and constructors on cv-qualified
9762 objects. Therefore, convert the INSTANCE to the unqualified
9763 type, if necessary. */
9764 if (!same_type_p (basetype, TREE_TYPE (instance)))
9765 {
9766 instance = build_this (instance);
9767 instance = build_nop (build_pointer_type (basetype), instance);
9768 instance = build_fold_indirect_ref (instance);
9769 }
9770 }
9771 else
9772 gcc_assert (!DECL_DESTRUCTOR_P (fn) && !DECL_CONSTRUCTOR_P (fn));
9773
9774 /* For the overload resolution we need to find the actual `this`
9775 that would be captured if the call turns out to be to a
9776 non-static member function. Do not actually capture it at this
9777 point. */
9778 if (DECL_CONSTRUCTOR_P (fn))
9779 /* Constructors don't use the enclosing 'this'. */
9780 first_mem_arg = instance;
9781 else
9782 first_mem_arg = maybe_resolve_dummy (instance, false);
9783
9784 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9785 p = conversion_obstack_alloc (0);
9786
9787 /* The number of arguments artificial parms in ARGS; we subtract one because
9788 there's no 'this' in ARGS. */
9789 unsigned skip = num_artificial_parms_for (fn) - 1;
9790
9791 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
9792 initializer, not T({ }). */
9793 if (DECL_CONSTRUCTOR_P (fn)
9794 && vec_safe_length (user_args) > skip
9795 && DIRECT_LIST_INIT_P ((*user_args)[skip]))
9796 {
9797 tree init_list = (*user_args)[skip];
9798 tree init = NULL_TREE;
9799
9800 gcc_assert (user_args->length () == skip + 1
9801 && !(flags & LOOKUP_ONLYCONVERTING));
9802
9803 /* If the initializer list has no elements and T is a class type with
9804 a default constructor, the object is value-initialized. Handle
9805 this here so we don't need to handle it wherever we use
9806 build_special_member_call. */
9807 if (CONSTRUCTOR_NELTS (init_list) == 0
9808 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
9809 /* For a user-provided default constructor, use the normal
9810 mechanisms so that protected access works. */
9811 && type_has_non_user_provided_default_constructor (basetype)
9812 && !processing_template_decl)
9813 init = build_value_init (basetype, complain);
9814
9815 /* If BASETYPE is an aggregate, we need to do aggregate
9816 initialization. */
9817 else if (CP_AGGREGATE_TYPE_P (basetype))
9818 {
9819 init = reshape_init (basetype, init_list, complain);
9820 init = digest_init (basetype, init, complain);
9821 }
9822
9823 if (init)
9824 {
9825 if (is_dummy_object (instance))
9826 return get_target_expr_sfinae (init, complain);
9827 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init);
9828 TREE_SIDE_EFFECTS (init) = true;
9829 return init;
9830 }
9831
9832 /* Otherwise go ahead with overload resolution. */
9833 add_list_candidates (fns, first_mem_arg, user_args,
9834 basetype, explicit_targs, template_only,
9835 conversion_path, access_binfo, flags,
9836 &candidates, complain);
9837 }
9838 else
9839 add_candidates (fns, first_mem_arg, user_args, optype,
9840 explicit_targs, template_only, conversion_path,
9841 access_binfo, flags, &candidates, complain);
9842
9843 any_viable_p = false;
9844 candidates = splice_viable (candidates, false, &any_viable_p);
9845
9846 if (!any_viable_p)
9847 {
9848 if (complain & tf_error)
9849 complain_about_no_candidates_for_method_call (instance, candidates,
9850 explicit_targs, basetype,
9851 optype, name,
9852 skip_first_for_error,
9853 user_args);
9854 call = error_mark_node;
9855 }
9856 else
9857 {
9858 cand = tourney (candidates, complain);
9859 if (cand == 0)
9860 {
9861 char *pretty_name;
9862 bool free_p;
9863 tree arglist;
9864
9865 if (complain & tf_error)
9866 {
9867 pretty_name = name_as_c_string (name, basetype, &free_p);
9868 arglist = build_tree_list_vec (user_args);
9869 if (skip_first_for_error)
9870 arglist = TREE_CHAIN (arglist);
9871 auto_diagnostic_group d;
9872 if (!any_strictly_viable (candidates))
9873 error ("no matching function for call to %<%s(%A)%>",
9874 pretty_name, arglist);
9875 else
9876 error ("call of overloaded %<%s(%A)%> is ambiguous",
9877 pretty_name, arglist);
9878 print_z_candidates (location_of (name), candidates);
9879 if (free_p)
9880 free (pretty_name);
9881 }
9882 call = error_mark_node;
9883 }
9884 else
9885 {
9886 fn = cand->fn;
9887 call = NULL_TREE;
9888
9889 if (!(flags & LOOKUP_NONVIRTUAL)
9890 && DECL_PURE_VIRTUAL_P (fn)
9891 && instance == current_class_ref
9892 && (complain & tf_warning))
9893 {
9894 /* This is not an error, it is runtime undefined
9895 behavior. */
9896 if (!current_function_decl)
9897 warning (0, "pure virtual %q#D called from "
9898 "non-static data member initializer", fn);
9899 else if (DECL_CONSTRUCTOR_P (current_function_decl)
9900 || DECL_DESTRUCTOR_P (current_function_decl))
9901 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl)
9902 ? G_("pure virtual %q#D called from constructor")
9903 : G_("pure virtual %q#D called from destructor")),
9904 fn);
9905 }
9906
9907 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
9908 && !DECL_CONSTRUCTOR_P (fn)
9909 && is_dummy_object (instance))
9910 {
9911 instance = maybe_resolve_dummy (instance, true);
9912 if (instance == error_mark_node)
9913 call = error_mark_node;
9914 else if (!is_dummy_object (instance))
9915 {
9916 /* We captured 'this' in the current lambda now that
9917 we know we really need it. */
9918 cand->first_arg = instance;
9919 }
9920 else if (any_dependent_bases_p ())
9921 /* We can't tell until instantiation time whether we can use
9922 *this as the implicit object argument. */;
9923 else
9924 {
9925 if (complain & tf_error)
9926 error ("cannot call member function %qD without object",
9927 fn);
9928 call = error_mark_node;
9929 }
9930 }
9931
9932 if (call != error_mark_node)
9933 {
9934 if (explicit_targs)
9935 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
9936 /* Now we know what function is being called. */
9937 if (fn_p)
9938 *fn_p = fn;
9939 /* Build the actual CALL_EXPR. */
9940 call = build_over_call (cand, flags, complain);
9941 /* In an expression of the form `a->f()' where `f' turns
9942 out to be a static member function, `a' is
9943 none-the-less evaluated. */
9944 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
9945 && !is_dummy_object (instance)
9946 && TREE_SIDE_EFFECTS (instance))
9947 {
9948 /* But avoid the implicit lvalue-rvalue conversion when 'a'
9949 is volatile. */
9950 tree a = instance;
9951 if (TREE_THIS_VOLATILE (a))
9952 a = build_this (a);
9953 if (TREE_SIDE_EFFECTS (a))
9954 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), a, call);
9955 }
9956 else if (call != error_mark_node
9957 && DECL_DESTRUCTOR_P (cand->fn)
9958 && !VOID_TYPE_P (TREE_TYPE (call)))
9959 /* An explicit call of the form "x->~X()" has type
9960 "void". However, on platforms where destructors
9961 return "this" (i.e., those where
9962 targetm.cxx.cdtor_returns_this is true), such calls
9963 will appear to have a return value of pointer type
9964 to the low-level call machinery. We do not want to
9965 change the low-level machinery, since we want to be
9966 able to optimize "delete f()" on such platforms as
9967 "operator delete(~X(f()))" (rather than generating
9968 "t = f(), ~X(t), operator delete (t)"). */
9969 call = build_nop (void_type_node, call);
9970 }
9971 }
9972 }
9973
9974 if (processing_template_decl && call != error_mark_node)
9975 {
9976 bool cast_to_void = false;
9977
9978 if (TREE_CODE (call) == COMPOUND_EXPR)
9979 call = TREE_OPERAND (call, 1);
9980 else if (TREE_CODE (call) == NOP_EXPR)
9981 {
9982 cast_to_void = true;
9983 call = TREE_OPERAND (call, 0);
9984 }
9985 if (INDIRECT_REF_P (call))
9986 call = TREE_OPERAND (call, 0);
9987 call = (build_min_non_dep_call_vec
9988 (call,
9989 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
9990 orig_instance, orig_fns, NULL_TREE),
9991 orig_args));
9992 SET_EXPR_LOCATION (call, input_location);
9993 call = convert_from_reference (call);
9994 if (cast_to_void)
9995 call = build_nop (void_type_node, call);
9996 }
9997
9998 /* Free all the conversions we allocated. */
9999 obstack_free (&conversion_obstack, p);
10000
10001 if (orig_args != NULL)
10002 release_tree_vector (orig_args);
10003
10004 return call;
10005 }
10006
10007 /* Wrapper for above. */
10008
10009 tree
build_new_method_call(tree instance,tree fns,vec<tree,va_gc> ** args,tree conversion_path,int flags,tree * fn_p,tsubst_flags_t complain)10010 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args,
10011 tree conversion_path, int flags,
10012 tree *fn_p, tsubst_flags_t complain)
10013 {
10014 tree ret;
10015 bool subtime = timevar_cond_start (TV_OVERLOAD);
10016 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags,
10017 fn_p, complain);
10018 timevar_cond_stop (TV_OVERLOAD, subtime);
10019 return ret;
10020 }
10021
10022 /* Returns true iff standard conversion sequence ICS1 is a proper
10023 subsequence of ICS2. */
10024
10025 static bool
is_subseq(conversion * ics1,conversion * ics2)10026 is_subseq (conversion *ics1, conversion *ics2)
10027 {
10028 /* We can assume that a conversion of the same code
10029 between the same types indicates a subsequence since we only get
10030 here if the types we are converting from are the same. */
10031
10032 while (ics1->kind == ck_rvalue
10033 || ics1->kind == ck_lvalue)
10034 ics1 = next_conversion (ics1);
10035
10036 while (1)
10037 {
10038 while (ics2->kind == ck_rvalue
10039 || ics2->kind == ck_lvalue)
10040 ics2 = next_conversion (ics2);
10041
10042 if (ics2->kind == ck_user
10043 || ics2->kind == ck_ambig
10044 || ics2->kind == ck_aggr
10045 || ics2->kind == ck_list
10046 || ics2->kind == ck_identity)
10047 /* At this point, ICS1 cannot be a proper subsequence of
10048 ICS2. We can get a USER_CONV when we are comparing the
10049 second standard conversion sequence of two user conversion
10050 sequences. */
10051 return false;
10052
10053 ics2 = next_conversion (ics2);
10054
10055 while (ics2->kind == ck_rvalue
10056 || ics2->kind == ck_lvalue)
10057 ics2 = next_conversion (ics2);
10058
10059 if (ics2->kind == ics1->kind
10060 && same_type_p (ics2->type, ics1->type)
10061 && (ics1->kind == ck_identity
10062 || same_type_p (next_conversion (ics2)->type,
10063 next_conversion (ics1)->type)))
10064 return true;
10065 }
10066 }
10067
10068 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
10069 be any _TYPE nodes. */
10070
10071 bool
is_properly_derived_from(tree derived,tree base)10072 is_properly_derived_from (tree derived, tree base)
10073 {
10074 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
10075 return false;
10076
10077 /* We only allow proper derivation here. The DERIVED_FROM_P macro
10078 considers every class derived from itself. */
10079 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
10080 && DERIVED_FROM_P (base, derived));
10081 }
10082
10083 /* We build the ICS for an implicit object parameter as a pointer
10084 conversion sequence. However, such a sequence should be compared
10085 as if it were a reference conversion sequence. If ICS is the
10086 implicit conversion sequence for an implicit object parameter,
10087 modify it accordingly. */
10088
10089 static void
maybe_handle_implicit_object(conversion ** ics)10090 maybe_handle_implicit_object (conversion **ics)
10091 {
10092 if ((*ics)->this_p)
10093 {
10094 /* [over.match.funcs]
10095
10096 For non-static member functions, the type of the
10097 implicit object parameter is "reference to cv X"
10098 where X is the class of which the function is a
10099 member and cv is the cv-qualification on the member
10100 function declaration. */
10101 conversion *t = *ics;
10102 tree reference_type;
10103
10104 /* The `this' parameter is a pointer to a class type. Make the
10105 implicit conversion talk about a reference to that same class
10106 type. */
10107 reference_type = TREE_TYPE (t->type);
10108 reference_type = build_reference_type (reference_type);
10109
10110 if (t->kind == ck_qual)
10111 t = next_conversion (t);
10112 if (t->kind == ck_ptr)
10113 t = next_conversion (t);
10114 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
10115 t = direct_reference_binding (reference_type, t);
10116 t->this_p = 1;
10117 t->rvaluedness_matches_p = 0;
10118 *ics = t;
10119 }
10120 }
10121
10122 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
10123 and return the initial reference binding conversion. Otherwise,
10124 leave *ICS unchanged and return NULL. */
10125
10126 static conversion *
maybe_handle_ref_bind(conversion ** ics)10127 maybe_handle_ref_bind (conversion **ics)
10128 {
10129 if ((*ics)->kind == ck_ref_bind)
10130 {
10131 conversion *old_ics = *ics;
10132 *ics = next_conversion (old_ics);
10133 (*ics)->user_conv_p = old_ics->user_conv_p;
10134 return old_ics;
10135 }
10136
10137 return NULL;
10138 }
10139
10140 /* Compare two implicit conversion sequences according to the rules set out in
10141 [over.ics.rank]. Return values:
10142
10143 1: ics1 is better than ics2
10144 -1: ics2 is better than ics1
10145 0: ics1 and ics2 are indistinguishable */
10146
10147 static int
compare_ics(conversion * ics1,conversion * ics2)10148 compare_ics (conversion *ics1, conversion *ics2)
10149 {
10150 tree from_type1;
10151 tree from_type2;
10152 tree to_type1;
10153 tree to_type2;
10154 tree deref_from_type1 = NULL_TREE;
10155 tree deref_from_type2 = NULL_TREE;
10156 tree deref_to_type1 = NULL_TREE;
10157 tree deref_to_type2 = NULL_TREE;
10158 conversion_rank rank1, rank2;
10159
10160 /* REF_BINDING is nonzero if the result of the conversion sequence
10161 is a reference type. In that case REF_CONV is the reference
10162 binding conversion. */
10163 conversion *ref_conv1;
10164 conversion *ref_conv2;
10165
10166 /* Compare badness before stripping the reference conversion. */
10167 if (ics1->bad_p > ics2->bad_p)
10168 return -1;
10169 else if (ics1->bad_p < ics2->bad_p)
10170 return 1;
10171
10172 /* Handle implicit object parameters. */
10173 maybe_handle_implicit_object (&ics1);
10174 maybe_handle_implicit_object (&ics2);
10175
10176 /* Handle reference parameters. */
10177 ref_conv1 = maybe_handle_ref_bind (&ics1);
10178 ref_conv2 = maybe_handle_ref_bind (&ics2);
10179
10180 /* List-initialization sequence L1 is a better conversion sequence than
10181 list-initialization sequence L2 if L1 converts to
10182 std::initializer_list<X> for some X and L2 does not. */
10183 if (ics1->kind == ck_list && ics2->kind != ck_list)
10184 return 1;
10185 if (ics2->kind == ck_list && ics1->kind != ck_list)
10186 return -1;
10187
10188 /* [over.ics.rank]
10189
10190 When comparing the basic forms of implicit conversion sequences (as
10191 defined in _over.best.ics_)
10192
10193 --a standard conversion sequence (_over.ics.scs_) is a better
10194 conversion sequence than a user-defined conversion sequence
10195 or an ellipsis conversion sequence, and
10196
10197 --a user-defined conversion sequence (_over.ics.user_) is a
10198 better conversion sequence than an ellipsis conversion sequence
10199 (_over.ics.ellipsis_). */
10200 /* Use BAD_CONVERSION_RANK because we already checked for a badness
10201 mismatch. If both ICS are bad, we try to make a decision based on
10202 what would have happened if they'd been good. This is not an
10203 extension, we'll still give an error when we build up the call; this
10204 just helps us give a more helpful error message. */
10205 rank1 = BAD_CONVERSION_RANK (ics1);
10206 rank2 = BAD_CONVERSION_RANK (ics2);
10207
10208 if (rank1 > rank2)
10209 return -1;
10210 else if (rank1 < rank2)
10211 return 1;
10212
10213 if (ics1->ellipsis_p)
10214 /* Both conversions are ellipsis conversions. */
10215 return 0;
10216
10217 /* User-defined conversion sequence U1 is a better conversion sequence
10218 than another user-defined conversion sequence U2 if they contain the
10219 same user-defined conversion operator or constructor and if the sec-
10220 ond standard conversion sequence of U1 is better than the second
10221 standard conversion sequence of U2. */
10222
10223 /* Handle list-conversion with the same code even though it isn't always
10224 ranked as a user-defined conversion and it doesn't have a second
10225 standard conversion sequence; it will still have the desired effect.
10226 Specifically, we need to do the reference binding comparison at the
10227 end of this function. */
10228
10229 if (ics1->user_conv_p || ics1->kind == ck_list
10230 || ics1->kind == ck_aggr || ics2->kind == ck_aggr)
10231 {
10232 conversion *t1;
10233 conversion *t2;
10234
10235 for (t1 = ics1; t1 && t1->kind != ck_user; t1 = next_conversion (t1))
10236 if (t1->kind == ck_ambig || t1->kind == ck_aggr
10237 || t1->kind == ck_list)
10238 break;
10239 for (t2 = ics2; t2 && t2->kind != ck_user; t2 = next_conversion (t2))
10240 if (t2->kind == ck_ambig || t2->kind == ck_aggr
10241 || t2->kind == ck_list)
10242 break;
10243
10244 if (!t1 || !t2 || t1->kind != t2->kind)
10245 return 0;
10246 else if (t1->kind == ck_user)
10247 {
10248 tree f1 = t1->cand ? t1->cand->fn : t1->type;
10249 tree f2 = t2->cand ? t2->cand->fn : t2->type;
10250 if (f1 != f2)
10251 return 0;
10252 }
10253 else
10254 {
10255 /* For ambiguous or aggregate conversions, use the target type as
10256 a proxy for the conversion function. */
10257 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
10258 return 0;
10259 }
10260
10261 /* We can just fall through here, after setting up
10262 FROM_TYPE1 and FROM_TYPE2. */
10263 from_type1 = t1->type;
10264 from_type2 = t2->type;
10265 }
10266 else
10267 {
10268 conversion *t1;
10269 conversion *t2;
10270
10271 /* We're dealing with two standard conversion sequences.
10272
10273 [over.ics.rank]
10274
10275 Standard conversion sequence S1 is a better conversion
10276 sequence than standard conversion sequence S2 if
10277
10278 --S1 is a proper subsequence of S2 (comparing the conversion
10279 sequences in the canonical form defined by _over.ics.scs_,
10280 excluding any Lvalue Transformation; the identity
10281 conversion sequence is considered to be a subsequence of
10282 any non-identity conversion sequence */
10283
10284 t1 = ics1;
10285 while (t1->kind != ck_identity)
10286 t1 = next_conversion (t1);
10287 from_type1 = t1->type;
10288
10289 t2 = ics2;
10290 while (t2->kind != ck_identity)
10291 t2 = next_conversion (t2);
10292 from_type2 = t2->type;
10293 }
10294
10295 /* One sequence can only be a subsequence of the other if they start with
10296 the same type. They can start with different types when comparing the
10297 second standard conversion sequence in two user-defined conversion
10298 sequences. */
10299 if (same_type_p (from_type1, from_type2))
10300 {
10301 if (is_subseq (ics1, ics2))
10302 return 1;
10303 if (is_subseq (ics2, ics1))
10304 return -1;
10305 }
10306
10307 /* [over.ics.rank]
10308
10309 Or, if not that,
10310
10311 --the rank of S1 is better than the rank of S2 (by the rules
10312 defined below):
10313
10314 Standard conversion sequences are ordered by their ranks: an Exact
10315 Match is a better conversion than a Promotion, which is a better
10316 conversion than a Conversion.
10317
10318 Two conversion sequences with the same rank are indistinguishable
10319 unless one of the following rules applies:
10320
10321 --A conversion that does not a convert a pointer, pointer to member,
10322 or std::nullptr_t to bool is better than one that does.
10323
10324 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
10325 so that we do not have to check it explicitly. */
10326 if (ics1->rank < ics2->rank)
10327 return 1;
10328 else if (ics2->rank < ics1->rank)
10329 return -1;
10330
10331 to_type1 = ics1->type;
10332 to_type2 = ics2->type;
10333
10334 /* A conversion from scalar arithmetic type to complex is worse than a
10335 conversion between scalar arithmetic types. */
10336 if (same_type_p (from_type1, from_type2)
10337 && ARITHMETIC_TYPE_P (from_type1)
10338 && ARITHMETIC_TYPE_P (to_type1)
10339 && ARITHMETIC_TYPE_P (to_type2)
10340 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
10341 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
10342 {
10343 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
10344 return -1;
10345 else
10346 return 1;
10347 }
10348
10349 if (TYPE_PTR_P (from_type1)
10350 && TYPE_PTR_P (from_type2)
10351 && TYPE_PTR_P (to_type1)
10352 && TYPE_PTR_P (to_type2))
10353 {
10354 deref_from_type1 = TREE_TYPE (from_type1);
10355 deref_from_type2 = TREE_TYPE (from_type2);
10356 deref_to_type1 = TREE_TYPE (to_type1);
10357 deref_to_type2 = TREE_TYPE (to_type2);
10358 }
10359 /* The rules for pointers to members A::* are just like the rules
10360 for pointers A*, except opposite: if B is derived from A then
10361 A::* converts to B::*, not vice versa. For that reason, we
10362 switch the from_ and to_ variables here. */
10363 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2)
10364 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2))
10365 || (TYPE_PTRMEMFUNC_P (from_type1)
10366 && TYPE_PTRMEMFUNC_P (from_type2)
10367 && TYPE_PTRMEMFUNC_P (to_type1)
10368 && TYPE_PTRMEMFUNC_P (to_type2)))
10369 {
10370 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
10371 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
10372 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
10373 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
10374 }
10375
10376 if (deref_from_type1 != NULL_TREE
10377 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
10378 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
10379 {
10380 /* This was one of the pointer or pointer-like conversions.
10381
10382 [over.ics.rank]
10383
10384 --If class B is derived directly or indirectly from class A,
10385 conversion of B* to A* is better than conversion of B* to
10386 void*, and conversion of A* to void* is better than
10387 conversion of B* to void*. */
10388 if (VOID_TYPE_P (deref_to_type1)
10389 && VOID_TYPE_P (deref_to_type2))
10390 {
10391 if (is_properly_derived_from (deref_from_type1,
10392 deref_from_type2))
10393 return -1;
10394 else if (is_properly_derived_from (deref_from_type2,
10395 deref_from_type1))
10396 return 1;
10397 }
10398 else if (VOID_TYPE_P (deref_to_type1)
10399 || VOID_TYPE_P (deref_to_type2))
10400 {
10401 if (same_type_p (deref_from_type1, deref_from_type2))
10402 {
10403 if (VOID_TYPE_P (deref_to_type2))
10404 {
10405 if (is_properly_derived_from (deref_from_type1,
10406 deref_to_type1))
10407 return 1;
10408 }
10409 /* We know that DEREF_TO_TYPE1 is `void' here. */
10410 else if (is_properly_derived_from (deref_from_type1,
10411 deref_to_type2))
10412 return -1;
10413 }
10414 }
10415 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
10416 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
10417 {
10418 /* [over.ics.rank]
10419
10420 --If class B is derived directly or indirectly from class A
10421 and class C is derived directly or indirectly from B,
10422
10423 --conversion of C* to B* is better than conversion of C* to
10424 A*,
10425
10426 --conversion of B* to A* is better than conversion of C* to
10427 A* */
10428 if (same_type_p (deref_from_type1, deref_from_type2))
10429 {
10430 if (is_properly_derived_from (deref_to_type1,
10431 deref_to_type2))
10432 return 1;
10433 else if (is_properly_derived_from (deref_to_type2,
10434 deref_to_type1))
10435 return -1;
10436 }
10437 else if (same_type_p (deref_to_type1, deref_to_type2))
10438 {
10439 if (is_properly_derived_from (deref_from_type2,
10440 deref_from_type1))
10441 return 1;
10442 else if (is_properly_derived_from (deref_from_type1,
10443 deref_from_type2))
10444 return -1;
10445 }
10446 }
10447 }
10448 else if (CLASS_TYPE_P (non_reference (from_type1))
10449 && same_type_p (from_type1, from_type2))
10450 {
10451 tree from = non_reference (from_type1);
10452
10453 /* [over.ics.rank]
10454
10455 --binding of an expression of type C to a reference of type
10456 B& is better than binding an expression of type C to a
10457 reference of type A&
10458
10459 --conversion of C to B is better than conversion of C to A, */
10460 if (is_properly_derived_from (from, to_type1)
10461 && is_properly_derived_from (from, to_type2))
10462 {
10463 if (is_properly_derived_from (to_type1, to_type2))
10464 return 1;
10465 else if (is_properly_derived_from (to_type2, to_type1))
10466 return -1;
10467 }
10468 }
10469 else if (CLASS_TYPE_P (non_reference (to_type1))
10470 && same_type_p (to_type1, to_type2))
10471 {
10472 tree to = non_reference (to_type1);
10473
10474 /* [over.ics.rank]
10475
10476 --binding of an expression of type B to a reference of type
10477 A& is better than binding an expression of type C to a
10478 reference of type A&,
10479
10480 --conversion of B to A is better than conversion of C to A */
10481 if (is_properly_derived_from (from_type1, to)
10482 && is_properly_derived_from (from_type2, to))
10483 {
10484 if (is_properly_derived_from (from_type2, from_type1))
10485 return 1;
10486 else if (is_properly_derived_from (from_type1, from_type2))
10487 return -1;
10488 }
10489 }
10490
10491 /* [over.ics.rank]
10492
10493 --S1 and S2 differ only in their qualification conversion and yield
10494 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
10495 qualification signature of type T1 is a proper subset of the cv-
10496 qualification signature of type T2 */
10497 if (ics1->kind == ck_qual
10498 && ics2->kind == ck_qual
10499 && same_type_p (from_type1, from_type2))
10500 {
10501 int result = comp_cv_qual_signature (to_type1, to_type2);
10502 if (result != 0)
10503 return result;
10504 }
10505
10506 /* [over.ics.rank]
10507
10508 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
10509 to an implicit object parameter of a non-static member function
10510 declared without a ref-qualifier, and either S1 binds an lvalue
10511 reference to an lvalue and S2 binds an rvalue reference or S1 binds an
10512 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
10513 draft standard, 13.3.3.2)
10514
10515 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
10516 types to which the references refer are the same type except for
10517 top-level cv-qualifiers, and the type to which the reference
10518 initialized by S2 refers is more cv-qualified than the type to
10519 which the reference initialized by S1 refers.
10520
10521 DR 1328 [over.match.best]: the context is an initialization by
10522 conversion function for direct reference binding (13.3.1.6) of a
10523 reference to function type, the return type of F1 is the same kind of
10524 reference (i.e. lvalue or rvalue) as the reference being initialized,
10525 and the return type of F2 is not. */
10526
10527 if (ref_conv1 && ref_conv2)
10528 {
10529 if (!ref_conv1->this_p && !ref_conv2->this_p
10530 && (ref_conv1->rvaluedness_matches_p
10531 != ref_conv2->rvaluedness_matches_p)
10532 && (same_type_p (ref_conv1->type, ref_conv2->type)
10533 || (TYPE_REF_IS_RVALUE (ref_conv1->type)
10534 != TYPE_REF_IS_RVALUE (ref_conv2->type))))
10535 {
10536 if (ref_conv1->bad_p
10537 && !same_type_p (TREE_TYPE (ref_conv1->type),
10538 TREE_TYPE (ref_conv2->type)))
10539 /* Don't prefer a bad conversion that drops cv-quals to a bad
10540 conversion with the wrong rvalueness. */
10541 return 0;
10542 return (ref_conv1->rvaluedness_matches_p
10543 - ref_conv2->rvaluedness_matches_p);
10544 }
10545
10546 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
10547 {
10548 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type));
10549 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type));
10550 if (ref_conv1->bad_p)
10551 {
10552 /* Prefer the one that drops fewer cv-quals. */
10553 tree ftype = next_conversion (ref_conv1)->type;
10554 int fquals = cp_type_quals (ftype);
10555 q1 ^= fquals;
10556 q2 ^= fquals;
10557 }
10558 return comp_cv_qualification (q2, q1);
10559 }
10560 }
10561
10562 /* Neither conversion sequence is better than the other. */
10563 return 0;
10564 }
10565
10566 /* The source type for this standard conversion sequence. */
10567
10568 static tree
source_type(conversion * t)10569 source_type (conversion *t)
10570 {
10571 for (;; t = next_conversion (t))
10572 {
10573 if (t->kind == ck_user
10574 || t->kind == ck_ambig
10575 || t->kind == ck_identity)
10576 return t->type;
10577 }
10578 gcc_unreachable ();
10579 }
10580
10581 /* Note a warning about preferring WINNER to LOSER. We do this by storing
10582 a pointer to LOSER and re-running joust to produce the warning if WINNER
10583 is actually used. */
10584
10585 static void
add_warning(struct z_candidate * winner,struct z_candidate * loser)10586 add_warning (struct z_candidate *winner, struct z_candidate *loser)
10587 {
10588 candidate_warning *cw = (candidate_warning *)
10589 conversion_obstack_alloc (sizeof (candidate_warning));
10590 cw->loser = loser;
10591 cw->next = winner->warnings;
10592 winner->warnings = cw;
10593 }
10594
10595 /* CAND is a constructor candidate in joust in C++17 and up. If it copies a
10596 prvalue returned from a conversion function, replace CAND with the candidate
10597 for the conversion and return true. Otherwise, return false. */
10598
10599 static bool
joust_maybe_elide_copy(z_candidate * & cand)10600 joust_maybe_elide_copy (z_candidate *&cand)
10601 {
10602 tree fn = cand->fn;
10603 if (!DECL_COPY_CONSTRUCTOR_P (fn) && !DECL_MOVE_CONSTRUCTOR_P (fn))
10604 return false;
10605 conversion *conv = cand->convs[0];
10606 gcc_checking_assert (conv->kind == ck_ref_bind);
10607 conv = next_conversion (conv);
10608 if (conv->kind == ck_user && !TYPE_REF_P (conv->type))
10609 {
10610 gcc_checking_assert (same_type_ignoring_top_level_qualifiers_p
10611 (conv->type, DECL_CONTEXT (fn)));
10612 z_candidate *uc = conv->cand;
10613 if (DECL_CONV_FN_P (uc->fn))
10614 {
10615 cand = uc;
10616 return true;
10617 }
10618 }
10619 return false;
10620 }
10621
10622 /* Compare two candidates for overloading as described in
10623 [over.match.best]. Return values:
10624
10625 1: cand1 is better than cand2
10626 -1: cand2 is better than cand1
10627 0: cand1 and cand2 are indistinguishable */
10628
10629 static int
joust(struct z_candidate * cand1,struct z_candidate * cand2,bool warn,tsubst_flags_t complain)10630 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn,
10631 tsubst_flags_t complain)
10632 {
10633 int winner = 0;
10634 int off1 = 0, off2 = 0;
10635 size_t i;
10636 size_t len;
10637
10638 /* Candidates that involve bad conversions are always worse than those
10639 that don't. */
10640 if (cand1->viable > cand2->viable)
10641 return 1;
10642 if (cand1->viable < cand2->viable)
10643 return -1;
10644
10645 /* If we have two pseudo-candidates for conversions to the same type,
10646 or two candidates for the same function, arbitrarily pick one. */
10647 if (cand1->fn == cand2->fn
10648 && (IS_TYPE_OR_DECL_P (cand1->fn)))
10649 return 1;
10650
10651 /* Prefer a non-deleted function over an implicitly deleted move
10652 constructor or assignment operator. This differs slightly from the
10653 wording for issue 1402 (which says the move op is ignored by overload
10654 resolution), but this way produces better error messages. */
10655 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
10656 && TREE_CODE (cand2->fn) == FUNCTION_DECL
10657 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn))
10658 {
10659 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn)
10660 && move_fn_p (cand1->fn))
10661 return -1;
10662 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn)
10663 && move_fn_p (cand2->fn))
10664 return 1;
10665 }
10666
10667 /* a viable function F1
10668 is defined to be a better function than another viable function F2 if
10669 for all arguments i, ICSi(F1) is not a worse conversion sequence than
10670 ICSi(F2), and then */
10671
10672 /* for some argument j, ICSj(F1) is a better conversion sequence than
10673 ICSj(F2) */
10674
10675 /* For comparing static and non-static member functions, we ignore
10676 the implicit object parameter of the non-static function. The
10677 standard says to pretend that the static function has an object
10678 parm, but that won't work with operator overloading. */
10679 len = cand1->num_convs;
10680 if (len != cand2->num_convs)
10681 {
10682 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
10683 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
10684
10685 if (DECL_CONSTRUCTOR_P (cand1->fn)
10686 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn))
10687 /* We're comparing a near-match list constructor and a near-match
10688 non-list constructor. Just treat them as unordered. */
10689 return 0;
10690
10691 gcc_assert (static_1 != static_2);
10692
10693 if (static_1)
10694 off2 = 1;
10695 else
10696 {
10697 off1 = 1;
10698 --len;
10699 }
10700 }
10701
10702 /* Handle C++17 copy elision in [over.match.ctor] (direct-init) context. The
10703 standard currently says that only constructors are candidates, but if one
10704 copies a prvalue returned by a conversion function we want to treat the
10705 conversion as the candidate instead.
10706
10707 Clang does something similar, as discussed at
10708 http://lists.isocpp.org/core/2017/10/3166.php
10709 http://lists.isocpp.org/core/2019/03/5721.php */
10710 int elided_tiebreaker = 0;
10711 if (len == 1 && cxx_dialect >= cxx17
10712 && DECL_P (cand1->fn)
10713 && DECL_COMPLETE_CONSTRUCTOR_P (cand1->fn)
10714 && !(cand1->flags & LOOKUP_ONLYCONVERTING))
10715 {
10716 bool elided1 = joust_maybe_elide_copy (cand1);
10717 bool elided2 = joust_maybe_elide_copy (cand2);
10718 /* As a tiebreaker below we will prefer a constructor to a conversion
10719 operator exposed this way. */
10720 elided_tiebreaker = elided2 - elided1;
10721 }
10722
10723 for (i = 0; i < len; ++i)
10724 {
10725 conversion *t1 = cand1->convs[i + off1];
10726 conversion *t2 = cand2->convs[i + off2];
10727 int comp = compare_ics (t1, t2);
10728
10729 if (comp != 0)
10730 {
10731 if ((complain & tf_warning)
10732 && warn_sign_promo
10733 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
10734 == cr_std + cr_promotion)
10735 && t1->kind == ck_std
10736 && t2->kind == ck_std
10737 && TREE_CODE (t1->type) == INTEGER_TYPE
10738 && TREE_CODE (t2->type) == INTEGER_TYPE
10739 && (TYPE_PRECISION (t1->type)
10740 == TYPE_PRECISION (t2->type))
10741 && (TYPE_UNSIGNED (next_conversion (t1)->type)
10742 || (TREE_CODE (next_conversion (t1)->type)
10743 == ENUMERAL_TYPE)))
10744 {
10745 tree type = next_conversion (t1)->type;
10746 tree type1, type2;
10747 struct z_candidate *w, *l;
10748 if (comp > 0)
10749 type1 = t1->type, type2 = t2->type,
10750 w = cand1, l = cand2;
10751 else
10752 type1 = t2->type, type2 = t1->type,
10753 w = cand2, l = cand1;
10754
10755 if (warn)
10756 {
10757 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
10758 type, type1, type2);
10759 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
10760 }
10761 else
10762 add_warning (w, l);
10763 }
10764
10765 if (winner && comp != winner)
10766 {
10767 winner = 0;
10768 goto tweak;
10769 }
10770 winner = comp;
10771 }
10772 }
10773
10774 /* warn about confusing overload resolution for user-defined conversions,
10775 either between a constructor and a conversion op, or between two
10776 conversion ops. */
10777 if ((complain & tf_warning)
10778 /* In C++17, the constructor might have been elided, which means that
10779 an originally null ->second_conv could become non-null. */
10780 && winner && warn_conversion && cand1->second_conv && cand2->second_conv
10781 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
10782 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
10783 {
10784 struct z_candidate *w, *l;
10785 bool give_warning = false;
10786
10787 if (winner == 1)
10788 w = cand1, l = cand2;
10789 else
10790 w = cand2, l = cand1;
10791
10792 /* We don't want to complain about `X::operator T1 ()'
10793 beating `X::operator T2 () const', when T2 is a no less
10794 cv-qualified version of T1. */
10795 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
10796 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
10797 {
10798 tree t = TREE_TYPE (TREE_TYPE (l->fn));
10799 tree f = TREE_TYPE (TREE_TYPE (w->fn));
10800
10801 if (TREE_CODE (t) == TREE_CODE (f) && INDIRECT_TYPE_P (t))
10802 {
10803 t = TREE_TYPE (t);
10804 f = TREE_TYPE (f);
10805 }
10806 if (!comp_ptr_ttypes (t, f))
10807 give_warning = true;
10808 }
10809 else
10810 give_warning = true;
10811
10812 if (!give_warning)
10813 /*NOP*/;
10814 else if (warn)
10815 {
10816 tree source = source_type (w->convs[0]);
10817 if (INDIRECT_TYPE_P (source))
10818 source = TREE_TYPE (source);
10819 auto_diagnostic_group d;
10820 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
10821 && warning (OPT_Wconversion, " for conversion from %qH to %qI",
10822 source, w->second_conv->type))
10823 {
10824 inform (input_location, " because conversion sequence for the argument is better");
10825 }
10826 }
10827 else
10828 add_warning (w, l);
10829 }
10830
10831 if (winner)
10832 return winner;
10833
10834 /* Put this tiebreaker first, so that we don't try to look at second_conv of
10835 a constructor candidate that doesn't have one. */
10836 if (elided_tiebreaker)
10837 return elided_tiebreaker;
10838
10839 /* DR 495 moved this tiebreaker above the template ones. */
10840 /* or, if not that,
10841 the context is an initialization by user-defined conversion (see
10842 _dcl.init_ and _over.match.user_) and the standard conversion
10843 sequence from the return type of F1 to the destination type (i.e.,
10844 the type of the entity being initialized) is a better conversion
10845 sequence than the standard conversion sequence from the return type
10846 of F2 to the destination type. */
10847
10848 if (cand1->second_conv)
10849 {
10850 winner = compare_ics (cand1->second_conv, cand2->second_conv);
10851 if (winner)
10852 return winner;
10853 }
10854
10855 /* or, if not that,
10856 F1 is a non-template function and F2 is a template function
10857 specialization. */
10858
10859 if (!cand1->template_decl && cand2->template_decl)
10860 return 1;
10861 else if (cand1->template_decl && !cand2->template_decl)
10862 return -1;
10863
10864 /* or, if not that,
10865 F1 and F2 are template functions and the function template for F1 is
10866 more specialized than the template for F2 according to the partial
10867 ordering rules. */
10868
10869 if (cand1->template_decl && cand2->template_decl)
10870 {
10871 winner = more_specialized_fn
10872 (TI_TEMPLATE (cand1->template_decl),
10873 TI_TEMPLATE (cand2->template_decl),
10874 /* [temp.func.order]: The presence of unused ellipsis and default
10875 arguments has no effect on the partial ordering of function
10876 templates. add_function_candidate() will not have
10877 counted the "this" argument for constructors. */
10878 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
10879 if (winner)
10880 return winner;
10881 }
10882
10883 // C++ Concepts
10884 // or, if not that, F1 is more constrained than F2.
10885 if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn))
10886 {
10887 winner = more_constrained (cand1->fn, cand2->fn);
10888 if (winner)
10889 return winner;
10890 }
10891
10892 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */
10893 if (deduction_guide_p (cand1->fn))
10894 {
10895 gcc_assert (deduction_guide_p (cand2->fn));
10896 /* We distinguish between candidates from an explicit deduction guide and
10897 candidates built from a constructor based on DECL_ARTIFICIAL. */
10898 int art1 = DECL_ARTIFICIAL (cand1->fn);
10899 int art2 = DECL_ARTIFICIAL (cand2->fn);
10900 if (art1 != art2)
10901 return art2 - art1;
10902
10903 if (art1)
10904 {
10905 /* Prefer the special copy guide over a declared copy/move
10906 constructor. */
10907 if (copy_guide_p (cand1->fn))
10908 return 1;
10909 if (copy_guide_p (cand2->fn))
10910 return -1;
10911
10912 /* Prefer a candidate generated from a non-template constructor. */
10913 int tg1 = template_guide_p (cand1->fn);
10914 int tg2 = template_guide_p (cand2->fn);
10915 if (tg1 != tg2)
10916 return tg2 - tg1;
10917 }
10918 }
10919
10920 /* F1 is a member of a class D, F2 is a member of a base class B of D, and
10921 for all arguments the corresponding parameters of F1 and F2 have the same
10922 type (CWG 2273/2277). */
10923 if (DECL_P (cand1->fn) && DECL_CLASS_SCOPE_P (cand1->fn)
10924 && !DECL_CONV_FN_P (cand1->fn)
10925 && DECL_P (cand2->fn) && DECL_CLASS_SCOPE_P (cand2->fn)
10926 && !DECL_CONV_FN_P (cand2->fn))
10927 {
10928 tree base1 = DECL_CONTEXT (strip_inheriting_ctors (cand1->fn));
10929 tree base2 = DECL_CONTEXT (strip_inheriting_ctors (cand2->fn));
10930
10931 bool used1 = false;
10932 bool used2 = false;
10933 if (base1 == base2)
10934 /* No difference. */;
10935 else if (DERIVED_FROM_P (base1, base2))
10936 used1 = true;
10937 else if (DERIVED_FROM_P (base2, base1))
10938 used2 = true;
10939
10940 if (int diff = used2 - used1)
10941 {
10942 for (i = 0; i < len; ++i)
10943 {
10944 conversion *t1 = cand1->convs[i + off1];
10945 conversion *t2 = cand2->convs[i + off2];
10946 if (!same_type_p (t1->type, t2->type))
10947 break;
10948 }
10949 if (i == len)
10950 return diff;
10951 }
10952 }
10953
10954 /* Check whether we can discard a builtin candidate, either because we
10955 have two identical ones or matching builtin and non-builtin candidates.
10956
10957 (Pedantically in the latter case the builtin which matched the user
10958 function should not be added to the overload set, but we spot it here.
10959
10960 [over.match.oper]
10961 ... the builtin candidates include ...
10962 - do not have the same parameter type list as any non-template
10963 non-member candidate. */
10964
10965 if (identifier_p (cand1->fn) || identifier_p (cand2->fn))
10966 {
10967 for (i = 0; i < len; ++i)
10968 if (!same_type_p (cand1->convs[i]->type,
10969 cand2->convs[i]->type))
10970 break;
10971 if (i == cand1->num_convs)
10972 {
10973 if (cand1->fn == cand2->fn)
10974 /* Two built-in candidates; arbitrarily pick one. */
10975 return 1;
10976 else if (identifier_p (cand1->fn))
10977 /* cand1 is built-in; prefer cand2. */
10978 return -1;
10979 else
10980 /* cand2 is built-in; prefer cand1. */
10981 return 1;
10982 }
10983 }
10984
10985 /* For candidates of a multi-versioned function, make the version with
10986 the highest priority win. This version will be checked for dispatching
10987 first. If this version can be inlined into the caller, the front-end
10988 will simply make a direct call to this function. */
10989
10990 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
10991 && DECL_FUNCTION_VERSIONED (cand1->fn)
10992 && TREE_CODE (cand2->fn) == FUNCTION_DECL
10993 && DECL_FUNCTION_VERSIONED (cand2->fn))
10994 {
10995 tree f1 = TREE_TYPE (cand1->fn);
10996 tree f2 = TREE_TYPE (cand2->fn);
10997 tree p1 = TYPE_ARG_TYPES (f1);
10998 tree p2 = TYPE_ARG_TYPES (f2);
10999
11000 /* Check if cand1->fn and cand2->fn are versions of the same function. It
11001 is possible that cand1->fn and cand2->fn are function versions but of
11002 different functions. Check types to see if they are versions of the same
11003 function. */
11004 if (compparms (p1, p2)
11005 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2)))
11006 {
11007 /* Always make the version with the higher priority, more
11008 specialized, win. */
11009 gcc_assert (targetm.compare_version_priority);
11010 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0)
11011 return 1;
11012 else
11013 return -1;
11014 }
11015 }
11016
11017 /* If the two function declarations represent the same function (this can
11018 happen with declarations in multiple scopes and arg-dependent lookup),
11019 arbitrarily choose one. But first make sure the default args we're
11020 using match. */
11021 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
11022 && equal_functions (cand1->fn, cand2->fn))
11023 {
11024 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
11025 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
11026
11027 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
11028
11029 for (i = 0; i < len; ++i)
11030 {
11031 /* Don't crash if the fn is variadic. */
11032 if (!parms1)
11033 break;
11034 parms1 = TREE_CHAIN (parms1);
11035 parms2 = TREE_CHAIN (parms2);
11036 }
11037
11038 if (off1)
11039 parms1 = TREE_CHAIN (parms1);
11040 else if (off2)
11041 parms2 = TREE_CHAIN (parms2);
11042
11043 for (; parms1; ++i)
11044 {
11045 if (!cp_tree_equal (TREE_PURPOSE (parms1),
11046 TREE_PURPOSE (parms2)))
11047 {
11048 if (warn)
11049 {
11050 if (complain & tf_error)
11051 {
11052 auto_diagnostic_group d;
11053 if (permerror (input_location,
11054 "default argument mismatch in "
11055 "overload resolution"))
11056 {
11057 inform (DECL_SOURCE_LOCATION (cand1->fn),
11058 " candidate 1: %q#F", cand1->fn);
11059 inform (DECL_SOURCE_LOCATION (cand2->fn),
11060 " candidate 2: %q#F", cand2->fn);
11061 }
11062 }
11063 else
11064 return 0;
11065 }
11066 else
11067 add_warning (cand1, cand2);
11068 break;
11069 }
11070 parms1 = TREE_CHAIN (parms1);
11071 parms2 = TREE_CHAIN (parms2);
11072 }
11073
11074 return 1;
11075 }
11076
11077 tweak:
11078
11079 /* Extension: If the worst conversion for one candidate is better than the
11080 worst conversion for the other, take the first. */
11081 if (!pedantic && (complain & tf_warning_or_error))
11082 {
11083 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
11084 struct z_candidate *w = 0, *l = 0;
11085
11086 for (i = 0; i < len; ++i)
11087 {
11088 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
11089 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
11090 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
11091 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
11092 }
11093 if (rank1 < rank2)
11094 winner = 1, w = cand1, l = cand2;
11095 if (rank1 > rank2)
11096 winner = -1, w = cand2, l = cand1;
11097 if (winner)
11098 {
11099 /* Don't choose a deleted function over ambiguity. */
11100 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
11101 return 0;
11102 if (warn)
11103 {
11104 auto_diagnostic_group d;
11105 if (pedwarn (input_location, 0,
11106 "ISO C++ says that these are ambiguous, even "
11107 "though the worst conversion for the first is "
11108 "better than the worst conversion for the second:"))
11109 {
11110 print_z_candidate (input_location, _("candidate 1:"), w);
11111 print_z_candidate (input_location, _("candidate 2:"), l);
11112 }
11113 }
11114 else
11115 add_warning (w, l);
11116 return winner;
11117 }
11118 }
11119
11120 gcc_assert (!winner);
11121 return 0;
11122 }
11123
11124 /* Given a list of candidates for overloading, find the best one, if any.
11125 This algorithm has a worst case of O(2n) (winner is last), and a best
11126 case of O(n/2) (totally ambiguous); much better than a sorting
11127 algorithm. */
11128
11129 static struct z_candidate *
tourney(struct z_candidate * candidates,tsubst_flags_t complain)11130 tourney (struct z_candidate *candidates, tsubst_flags_t complain)
11131 {
11132 struct z_candidate *champ = candidates, *challenger;
11133 int fate;
11134 int champ_compared_to_predecessor = 0;
11135
11136 /* Walk through the list once, comparing each current champ to the next
11137 candidate, knocking out a candidate or two with each comparison. */
11138
11139 for (challenger = champ->next; challenger; )
11140 {
11141 fate = joust (champ, challenger, 0, complain);
11142 if (fate == 1)
11143 challenger = challenger->next;
11144 else
11145 {
11146 if (fate == 0)
11147 {
11148 champ = challenger->next;
11149 if (champ == 0)
11150 return NULL;
11151 champ_compared_to_predecessor = 0;
11152 }
11153 else
11154 {
11155 champ = challenger;
11156 champ_compared_to_predecessor = 1;
11157 }
11158
11159 challenger = champ->next;
11160 }
11161 }
11162
11163 /* Make sure the champ is better than all the candidates it hasn't yet
11164 been compared to. */
11165
11166 for (challenger = candidates;
11167 challenger != champ
11168 && !(champ_compared_to_predecessor && challenger->next == champ);
11169 challenger = challenger->next)
11170 {
11171 fate = joust (champ, challenger, 0, complain);
11172 if (fate != 1)
11173 return NULL;
11174 }
11175
11176 return champ;
11177 }
11178
11179 /* Returns nonzero if things of type FROM can be converted to TO. */
11180
11181 bool
can_convert(tree to,tree from,tsubst_flags_t complain)11182 can_convert (tree to, tree from, tsubst_flags_t complain)
11183 {
11184 tree arg = NULL_TREE;
11185 /* implicit_conversion only considers user-defined conversions
11186 if it has an expression for the call argument list. */
11187 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to))
11188 arg = build1 (CAST_EXPR, from, NULL_TREE);
11189 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain);
11190 }
11191
11192 /* Returns nonzero if things of type FROM can be converted to TO with a
11193 standard conversion. */
11194
11195 bool
can_convert_standard(tree to,tree from,tsubst_flags_t complain)11196 can_convert_standard (tree to, tree from, tsubst_flags_t complain)
11197 {
11198 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain);
11199 }
11200
11201 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
11202
11203 bool
can_convert_arg(tree to,tree from,tree arg,int flags,tsubst_flags_t complain)11204 can_convert_arg (tree to, tree from, tree arg, int flags,
11205 tsubst_flags_t complain)
11206 {
11207 conversion *t;
11208 void *p;
11209 bool ok_p;
11210
11211 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11212 p = conversion_obstack_alloc (0);
11213 /* We want to discard any access checks done for this test,
11214 as we might not be in the appropriate access context and
11215 we'll do the check again when we actually perform the
11216 conversion. */
11217 push_deferring_access_checks (dk_deferred);
11218
11219 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
11220 flags, complain);
11221 ok_p = (t && !t->bad_p);
11222
11223 /* Discard the access checks now. */
11224 pop_deferring_access_checks ();
11225 /* Free all the conversions we allocated. */
11226 obstack_free (&conversion_obstack, p);
11227
11228 return ok_p;
11229 }
11230
11231 /* Like can_convert_arg, but allows dubious conversions as well. */
11232
11233 bool
can_convert_arg_bad(tree to,tree from,tree arg,int flags,tsubst_flags_t complain)11234 can_convert_arg_bad (tree to, tree from, tree arg, int flags,
11235 tsubst_flags_t complain)
11236 {
11237 conversion *t;
11238 void *p;
11239
11240 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11241 p = conversion_obstack_alloc (0);
11242 /* Try to perform the conversion. */
11243 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
11244 flags, complain);
11245 /* Free all the conversions we allocated. */
11246 obstack_free (&conversion_obstack, p);
11247
11248 return t != NULL;
11249 }
11250
11251 /* Convert EXPR to TYPE. Return the converted expression.
11252
11253 Note that we allow bad conversions here because by the time we get to
11254 this point we are committed to doing the conversion. If we end up
11255 doing a bad conversion, convert_like will complain. */
11256
11257 tree
perform_implicit_conversion_flags(tree type,tree expr,tsubst_flags_t complain,int flags)11258 perform_implicit_conversion_flags (tree type, tree expr,
11259 tsubst_flags_t complain, int flags)
11260 {
11261 conversion *conv;
11262 void *p;
11263 location_t loc = cp_expr_loc_or_loc (expr, input_location);
11264
11265 if (TYPE_REF_P (type))
11266 expr = mark_lvalue_use (expr);
11267 else
11268 expr = mark_rvalue_use (expr);
11269
11270 if (error_operand_p (expr))
11271 return error_mark_node;
11272
11273 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11274 p = conversion_obstack_alloc (0);
11275
11276 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
11277 /*c_cast_p=*/false,
11278 flags, complain);
11279
11280 if (!conv)
11281 {
11282 if (complain & tf_error)
11283 {
11284 /* If expr has unknown type, then it is an overloaded function.
11285 Call instantiate_type to get good error messages. */
11286 if (TREE_TYPE (expr) == unknown_type_node)
11287 instantiate_type (type, expr, complain);
11288 else if (invalid_nonstatic_memfn_p (loc, expr, complain))
11289 /* We gave an error. */;
11290 else
11291 {
11292 range_label_for_type_mismatch label (TREE_TYPE (expr), type);
11293 gcc_rich_location rich_loc (loc, &label);
11294 error_at (&rich_loc, "could not convert %qE from %qH to %qI",
11295 expr, TREE_TYPE (expr), type);
11296 }
11297 }
11298 expr = error_mark_node;
11299 }
11300 else if (processing_template_decl && conv->kind != ck_identity)
11301 {
11302 /* In a template, we are only concerned about determining the
11303 type of non-dependent expressions, so we do not have to
11304 perform the actual conversion. But for initializers, we
11305 need to be able to perform it at instantiation
11306 (or instantiate_non_dependent_expr) time. */
11307 expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
11308 if (!(flags & LOOKUP_ONLYCONVERTING))
11309 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
11310 if (flags & LOOKUP_NO_NARROWING)
11311 IMPLICIT_CONV_EXPR_BRACED_INIT (expr) = true;
11312 }
11313 else
11314 expr = convert_like (conv, expr, complain);
11315
11316 /* Free all the conversions we allocated. */
11317 obstack_free (&conversion_obstack, p);
11318
11319 return expr;
11320 }
11321
11322 tree
perform_implicit_conversion(tree type,tree expr,tsubst_flags_t complain)11323 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
11324 {
11325 return perform_implicit_conversion_flags (type, expr, complain,
11326 LOOKUP_IMPLICIT);
11327 }
11328
11329 /* Convert EXPR to TYPE (as a direct-initialization) if that is
11330 permitted. If the conversion is valid, the converted expression is
11331 returned. Otherwise, NULL_TREE is returned, except in the case
11332 that TYPE is a class type; in that case, an error is issued. If
11333 C_CAST_P is true, then this direct-initialization is taking
11334 place as part of a static_cast being attempted as part of a C-style
11335 cast. */
11336
11337 tree
perform_direct_initialization_if_possible(tree type,tree expr,bool c_cast_p,tsubst_flags_t complain)11338 perform_direct_initialization_if_possible (tree type,
11339 tree expr,
11340 bool c_cast_p,
11341 tsubst_flags_t complain)
11342 {
11343 conversion *conv;
11344 void *p;
11345
11346 if (type == error_mark_node || error_operand_p (expr))
11347 return error_mark_node;
11348 /* [dcl.init]
11349
11350 If the destination type is a (possibly cv-qualified) class type:
11351
11352 -- If the initialization is direct-initialization ...,
11353 constructors are considered. ... If no constructor applies, or
11354 the overload resolution is ambiguous, the initialization is
11355 ill-formed. */
11356 if (CLASS_TYPE_P (type))
11357 {
11358 vec<tree, va_gc> *args = make_tree_vector_single (expr);
11359 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
11360 &args, type, LOOKUP_NORMAL, complain);
11361 release_tree_vector (args);
11362 return build_cplus_new (type, expr, complain);
11363 }
11364
11365 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11366 p = conversion_obstack_alloc (0);
11367
11368 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
11369 c_cast_p,
11370 LOOKUP_NORMAL, complain);
11371 if (!conv || conv->bad_p)
11372 expr = NULL_TREE;
11373 else if (processing_template_decl && conv->kind != ck_identity)
11374 {
11375 /* In a template, we are only concerned about determining the
11376 type of non-dependent expressions, so we do not have to
11377 perform the actual conversion. But for initializers, we
11378 need to be able to perform it at instantiation
11379 (or instantiate_non_dependent_expr) time. */
11380 expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
11381 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
11382 }
11383 else
11384 expr = convert_like_real (conv, expr, NULL_TREE, 0,
11385 /*issue_conversion_warnings=*/false,
11386 c_cast_p,
11387 complain);
11388
11389 /* Free all the conversions we allocated. */
11390 obstack_free (&conversion_obstack, p);
11391
11392 return expr;
11393 }
11394
11395 /* When initializing a reference that lasts longer than a full-expression,
11396 this special rule applies:
11397
11398 [class.temporary]
11399
11400 The temporary to which the reference is bound or the temporary
11401 that is the complete object to which the reference is bound
11402 persists for the lifetime of the reference.
11403
11404 The temporaries created during the evaluation of the expression
11405 initializing the reference, except the temporary to which the
11406 reference is bound, are destroyed at the end of the
11407 full-expression in which they are created.
11408
11409 In that case, we store the converted expression into a new
11410 VAR_DECL in a new scope.
11411
11412 However, we want to be careful not to create temporaries when
11413 they are not required. For example, given:
11414
11415 struct B {};
11416 struct D : public B {};
11417 D f();
11418 const B& b = f();
11419
11420 there is no need to copy the return value from "f"; we can just
11421 extend its lifetime. Similarly, given:
11422
11423 struct S {};
11424 struct T { operator S(); };
11425 T t;
11426 const S& s = t;
11427
11428 we can extend the lifetime of the return value of the conversion
11429 operator.
11430
11431 The next several functions are involved in this lifetime extension. */
11432
11433 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The
11434 reference is being bound to a temporary. Create and return a new
11435 VAR_DECL with the indicated TYPE; this variable will store the value to
11436 which the reference is bound. */
11437
11438 tree
make_temporary_var_for_ref_to_temp(tree decl,tree type)11439 make_temporary_var_for_ref_to_temp (tree decl, tree type)
11440 {
11441 tree var = create_temporary_var (type);
11442
11443 /* Register the variable. */
11444 if (VAR_P (decl)
11445 && (TREE_STATIC (decl) || CP_DECL_THREAD_LOCAL_P (decl)))
11446 {
11447 /* Namespace-scope or local static; give it a mangled name. */
11448
11449 /* If an initializer is visible to multiple translation units, those
11450 translation units must agree on the addresses of the
11451 temporaries. Therefore the temporaries must be given a consistent name
11452 and vague linkage. The mangled name of a temporary is the name of the
11453 non-temporary object in whose initializer they appear, prefixed with
11454 GR and suffixed with a sequence number mangled using the usual rules
11455 for a seq-id. Temporaries are numbered with a pre-order, depth-first,
11456 left-to-right walk of the complete initializer. */
11457
11458 TREE_STATIC (var) = TREE_STATIC (decl);
11459 TREE_PUBLIC (var) = TREE_PUBLIC (decl);
11460 if (decl_anon_ns_mem_p (decl))
11461 TREE_PUBLIC (var) = 0;
11462 if (vague_linkage_p (decl))
11463 comdat_linkage (var);
11464
11465 CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl);
11466 set_decl_tls_model (var, DECL_TLS_MODEL (decl));
11467
11468 tree name = mangle_ref_init_variable (decl);
11469 DECL_NAME (var) = name;
11470 SET_DECL_ASSEMBLER_NAME (var, name);
11471 }
11472 else
11473 /* Create a new cleanup level if necessary. */
11474 maybe_push_cleanup_level (type);
11475
11476 return pushdecl (var);
11477 }
11478
11479 /* EXPR is the initializer for a variable DECL of reference or
11480 std::initializer_list type. Create, push and return a new VAR_DECL
11481 for the initializer so that it will live as long as DECL. Any
11482 cleanup for the new variable is returned through CLEANUP, and the
11483 code to initialize the new variable is returned through INITP. */
11484
11485 static tree
set_up_extended_ref_temp(tree decl,tree expr,vec<tree,va_gc> ** cleanups,tree * initp,tree * cond_guard)11486 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups,
11487 tree *initp, tree *cond_guard)
11488 {
11489 tree init;
11490 tree type;
11491 tree var;
11492
11493 /* Create the temporary variable. */
11494 type = TREE_TYPE (expr);
11495 var = make_temporary_var_for_ref_to_temp (decl, type);
11496 layout_decl (var, 0);
11497 /* If the rvalue is the result of a function call it will be
11498 a TARGET_EXPR. If it is some other construct (such as a
11499 member access expression where the underlying object is
11500 itself the result of a function call), turn it into a
11501 TARGET_EXPR here. It is important that EXPR be a
11502 TARGET_EXPR below since otherwise the INIT_EXPR will
11503 attempt to make a bitwise copy of EXPR to initialize
11504 VAR. */
11505 if (TREE_CODE (expr) != TARGET_EXPR)
11506 expr = get_target_expr (expr);
11507
11508 if (TREE_CODE (decl) == FIELD_DECL
11509 && extra_warnings && !TREE_NO_WARNING (decl))
11510 {
11511 warning (OPT_Wextra, "a temporary bound to %qD only persists "
11512 "until the constructor exits", decl);
11513 TREE_NO_WARNING (decl) = true;
11514 }
11515
11516 /* Recursively extend temps in this initializer. */
11517 TARGET_EXPR_INITIAL (expr)
11518 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups,
11519 cond_guard);
11520
11521 /* Any reference temp has a non-trivial initializer. */
11522 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true;
11523
11524 /* If the initializer is constant, put it in DECL_INITIAL so we get
11525 static initialization and use in constant expressions. */
11526 init = maybe_constant_init (expr);
11527 /* As in store_init_value. */
11528 init = cp_fully_fold (init);
11529 if (TREE_CONSTANT (init))
11530 {
11531 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
11532 {
11533 /* 5.19 says that a constant expression can include an
11534 lvalue-rvalue conversion applied to "a glvalue of literal type
11535 that refers to a non-volatile temporary object initialized
11536 with a constant expression". Rather than try to communicate
11537 that this VAR_DECL is a temporary, just mark it constexpr. */
11538 DECL_DECLARED_CONSTEXPR_P (var) = true;
11539 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
11540 TREE_CONSTANT (var) = true;
11541 TREE_READONLY (var) = true;
11542 }
11543 DECL_INITIAL (var) = init;
11544 init = NULL_TREE;
11545 }
11546 else
11547 /* Create the INIT_EXPR that will initialize the temporary
11548 variable. */
11549 init = split_nonconstant_init (var, expr);
11550 if (at_function_scope_p ())
11551 {
11552 add_decl_expr (var);
11553
11554 if (TREE_STATIC (var))
11555 init = add_stmt_to_compound (init, register_dtor_fn (var));
11556 else
11557 {
11558 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error);
11559 if (cleanup)
11560 {
11561 if (cond_guard && cleanup != error_mark_node)
11562 {
11563 if (*cond_guard == NULL_TREE)
11564 {
11565 *cond_guard = build_decl (input_location, VAR_DECL,
11566 NULL_TREE, boolean_type_node);
11567 DECL_ARTIFICIAL (*cond_guard) = 1;
11568 DECL_IGNORED_P (*cond_guard) = 1;
11569 DECL_CONTEXT (*cond_guard) = current_function_decl;
11570 layout_decl (*cond_guard, 0);
11571 add_decl_expr (*cond_guard);
11572 tree set = cp_build_modify_expr (UNKNOWN_LOCATION,
11573 *cond_guard, NOP_EXPR,
11574 boolean_false_node,
11575 tf_warning_or_error);
11576 finish_expr_stmt (set);
11577 }
11578 cleanup = build3 (COND_EXPR, void_type_node,
11579 *cond_guard, cleanup, NULL_TREE);
11580 }
11581 vec_safe_push (*cleanups, cleanup);
11582 }
11583 }
11584
11585 /* We must be careful to destroy the temporary only
11586 after its initialization has taken place. If the
11587 initialization throws an exception, then the
11588 destructor should not be run. We cannot simply
11589 transform INIT into something like:
11590
11591 (INIT, ({ CLEANUP_STMT; }))
11592
11593 because emit_local_var always treats the
11594 initializer as a full-expression. Thus, the
11595 destructor would run too early; it would run at the
11596 end of initializing the reference variable, rather
11597 than at the end of the block enclosing the
11598 reference variable.
11599
11600 The solution is to pass back a cleanup expression
11601 which the caller is responsible for attaching to
11602 the statement tree. */
11603 }
11604 else
11605 {
11606 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
11607 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
11608 {
11609 if (CP_DECL_THREAD_LOCAL_P (var))
11610 tls_aggregates = tree_cons (NULL_TREE, var,
11611 tls_aggregates);
11612 else
11613 static_aggregates = tree_cons (NULL_TREE, var,
11614 static_aggregates);
11615 }
11616 else
11617 /* Check whether the dtor is callable. */
11618 cxx_maybe_build_cleanup (var, tf_warning_or_error);
11619 }
11620 /* Avoid -Wunused-variable warning (c++/38958). */
11621 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
11622 && VAR_P (decl))
11623 TREE_USED (decl) = DECL_READ_P (decl) = true;
11624
11625 *initp = init;
11626 return var;
11627 }
11628
11629 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
11630 initializing a variable of that TYPE. */
11631
11632 tree
initialize_reference(tree type,tree expr,int flags,tsubst_flags_t complain)11633 initialize_reference (tree type, tree expr,
11634 int flags, tsubst_flags_t complain)
11635 {
11636 conversion *conv;
11637 void *p;
11638 location_t loc = cp_expr_loc_or_loc (expr, input_location);
11639
11640 if (type == error_mark_node || error_operand_p (expr))
11641 return error_mark_node;
11642
11643 /* Get the high-water mark for the CONVERSION_OBSTACK. */
11644 p = conversion_obstack_alloc (0);
11645
11646 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
11647 flags, complain);
11648 if (!conv || conv->bad_p)
11649 {
11650 if (complain & tf_error)
11651 {
11652 if (conv)
11653 convert_like (conv, expr, complain);
11654 else if (!CP_TYPE_CONST_P (TREE_TYPE (type))
11655 && !TYPE_REF_IS_RVALUE (type)
11656 && !lvalue_p (expr))
11657 error_at (loc, "invalid initialization of non-const reference of "
11658 "type %qH from an rvalue of type %qI",
11659 type, TREE_TYPE (expr));
11660 else
11661 error_at (loc, "invalid initialization of reference of type "
11662 "%qH from expression of type %qI", type,
11663 TREE_TYPE (expr));
11664 }
11665 return error_mark_node;
11666 }
11667
11668 if (conv->kind == ck_ref_bind)
11669 /* Perform the conversion. */
11670 expr = convert_like (conv, expr, complain);
11671 else if (conv->kind == ck_ambig)
11672 /* We gave an error in build_user_type_conversion_1. */
11673 expr = error_mark_node;
11674 else
11675 gcc_unreachable ();
11676
11677 /* Free all the conversions we allocated. */
11678 obstack_free (&conversion_obstack, p);
11679
11680 return expr;
11681 }
11682
11683 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer,
11684 which is bound either to a reference or a std::initializer_list. */
11685
11686 static tree
extend_ref_init_temps_1(tree decl,tree init,vec<tree,va_gc> ** cleanups,tree * cond_guard)11687 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups,
11688 tree *cond_guard)
11689 {
11690 tree sub = init;
11691 tree *p;
11692 STRIP_NOPS (sub);
11693 if (TREE_CODE (sub) == COMPOUND_EXPR)
11694 {
11695 TREE_OPERAND (sub, 1)
11696 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups,
11697 cond_guard);
11698 return init;
11699 }
11700 if (TREE_CODE (sub) == COND_EXPR)
11701 {
11702 tree cur_cond_guard = NULL_TREE;
11703 if (TREE_OPERAND (sub, 1))
11704 TREE_OPERAND (sub, 1)
11705 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups,
11706 &cur_cond_guard);
11707 if (cur_cond_guard)
11708 {
11709 tree set = cp_build_modify_expr (UNKNOWN_LOCATION, cur_cond_guard,
11710 NOP_EXPR, boolean_true_node,
11711 tf_warning_or_error);
11712 TREE_OPERAND (sub, 1)
11713 = cp_build_compound_expr (set, TREE_OPERAND (sub, 1),
11714 tf_warning_or_error);
11715 }
11716 cur_cond_guard = NULL_TREE;
11717 if (TREE_OPERAND (sub, 2))
11718 TREE_OPERAND (sub, 2)
11719 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 2), cleanups,
11720 &cur_cond_guard);
11721 if (cur_cond_guard)
11722 {
11723 tree set = cp_build_modify_expr (UNKNOWN_LOCATION, cur_cond_guard,
11724 NOP_EXPR, boolean_true_node,
11725 tf_warning_or_error);
11726 TREE_OPERAND (sub, 2)
11727 = cp_build_compound_expr (set, TREE_OPERAND (sub, 2),
11728 tf_warning_or_error);
11729 }
11730 return init;
11731 }
11732 if (TREE_CODE (sub) != ADDR_EXPR)
11733 return init;
11734 /* Deal with binding to a subobject. */
11735 for (p = &TREE_OPERAND (sub, 0);
11736 TREE_CODE (*p) == COMPONENT_REF || TREE_CODE (*p) == ARRAY_REF; )
11737 p = &TREE_OPERAND (*p, 0);
11738 if (TREE_CODE (*p) == TARGET_EXPR)
11739 {
11740 tree subinit = NULL_TREE;
11741 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit, cond_guard);
11742 recompute_tree_invariant_for_addr_expr (sub);
11743 if (init != sub)
11744 init = fold_convert (TREE_TYPE (init), sub);
11745 if (subinit)
11746 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init);
11747 }
11748 return init;
11749 }
11750
11751 /* INIT is part of the initializer for DECL. If there are any
11752 reference or initializer lists being initialized, extend their
11753 lifetime to match that of DECL. */
11754
11755 tree
extend_ref_init_temps(tree decl,tree init,vec<tree,va_gc> ** cleanups,tree * cond_guard)11756 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups,
11757 tree *cond_guard)
11758 {
11759 tree type = TREE_TYPE (init);
11760 if (processing_template_decl)
11761 return init;
11762 if (TYPE_REF_P (type))
11763 init = extend_ref_init_temps_1 (decl, init, cleanups, cond_guard);
11764 else
11765 {
11766 tree ctor = init;
11767 if (TREE_CODE (ctor) == TARGET_EXPR)
11768 ctor = TARGET_EXPR_INITIAL (ctor);
11769 if (TREE_CODE (ctor) == CONSTRUCTOR)
11770 {
11771 if (is_std_init_list (type))
11772 {
11773 /* The temporary array underlying a std::initializer_list
11774 is handled like a reference temporary. */
11775 tree array = CONSTRUCTOR_ELT (ctor, 0)->value;
11776 array = extend_ref_init_temps_1 (decl, array, cleanups,
11777 cond_guard);
11778 CONSTRUCTOR_ELT (ctor, 0)->value = array;
11779 }
11780 else
11781 {
11782 unsigned i;
11783 constructor_elt *p;
11784 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor);
11785 FOR_EACH_VEC_SAFE_ELT (elts, i, p)
11786 p->value = extend_ref_init_temps (decl, p->value, cleanups,
11787 cond_guard);
11788 }
11789 recompute_constructor_flags (ctor);
11790 if (decl_maybe_constant_var_p (decl) && TREE_CONSTANT (ctor))
11791 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true;
11792 }
11793 }
11794
11795 return init;
11796 }
11797
11798 /* Returns true iff an initializer for TYPE could contain temporaries that
11799 need to be extended because they are bound to references or
11800 std::initializer_list. */
11801
11802 bool
type_has_extended_temps(tree type)11803 type_has_extended_temps (tree type)
11804 {
11805 type = strip_array_types (type);
11806 if (TYPE_REF_P (type))
11807 return true;
11808 if (CLASS_TYPE_P (type))
11809 {
11810 if (is_std_init_list (type))
11811 return true;
11812 for (tree f = next_initializable_field (TYPE_FIELDS (type));
11813 f; f = next_initializable_field (DECL_CHAIN (f)))
11814 if (type_has_extended_temps (TREE_TYPE (f)))
11815 return true;
11816 }
11817 return false;
11818 }
11819
11820 /* Returns true iff TYPE is some variant of std::initializer_list. */
11821
11822 bool
is_std_init_list(tree type)11823 is_std_init_list (tree type)
11824 {
11825 if (!TYPE_P (type))
11826 return false;
11827 if (cxx_dialect == cxx98)
11828 return false;
11829 /* Look through typedefs. */
11830 type = TYPE_MAIN_VARIANT (type);
11831 return (CLASS_TYPE_P (type)
11832 && CP_TYPE_CONTEXT (type) == std_node
11833 && init_list_identifier == DECL_NAME (TYPE_NAME (type)));
11834 }
11835
11836 /* Returns true iff DECL is a list constructor: i.e. a constructor which
11837 will accept an argument list of a single std::initializer_list<T>. */
11838
11839 bool
is_list_ctor(tree decl)11840 is_list_ctor (tree decl)
11841 {
11842 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
11843 tree arg;
11844
11845 if (!args || args == void_list_node)
11846 return false;
11847
11848 arg = non_reference (TREE_VALUE (args));
11849 if (!is_std_init_list (arg))
11850 return false;
11851
11852 args = TREE_CHAIN (args);
11853
11854 if (args && args != void_list_node && !TREE_PURPOSE (args))
11855 /* There are more non-defaulted parms. */
11856 return false;
11857
11858 return true;
11859 }
11860
11861 #include "gt-cp-call.h"
11862