1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987-2015 Free Software Foundation, Inc.
3 Contributed by Michael Tiemann (tiemann@cygnus.com) and
4 modified by Brendan Kehoe (brendan@cygnus.com).
6 This file is part of GCC.
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)
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.
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/>. */
23 /* High-level class interface. */
27 #include "coretypes.h"
32 #include "double-int.h"
39 #include "stor-layout.h"
40 #include "trans-mem.h"
41 #include "stringpool.h"
45 #include "diagnostic-core.h"
49 #include "langhooks.h"
50 #include "c-family/c-objc.h"
54 #include "plugin-api.h"
55 #include "hard-reg-set.h"
61 #include "internal-fn.h"
63 /* The various kinds of conversion. */
65 typedef enum conversion_kind {
81 /* The rank of the conversion. Order of the enumerals matters; better
82 conversions should come earlier in the list. */
84 typedef enum conversion_rank {
95 /* An implicit conversion sequence, in the sense of [over.best.ics].
96 The first conversion to be performed is at the end of the chain.
97 That conversion is always a cr_identity conversion. */
99 typedef struct conversion conversion;
101 /* The kind of conversion represented by this step. */
102 conversion_kind kind;
103 /* The rank of this conversion. */
104 conversion_rank rank;
105 BOOL_BITFIELD user_conv_p : 1;
106 BOOL_BITFIELD ellipsis_p : 1;
107 BOOL_BITFIELD this_p : 1;
108 /* True if this conversion would be permitted with a bending of
109 language standards, e.g. disregarding pointer qualifiers or
110 converting integers to pointers. */
111 BOOL_BITFIELD bad_p : 1;
112 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
113 temporary should be created to hold the result of the
115 BOOL_BITFIELD need_temporary_p : 1;
116 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
117 from a pointer-to-derived to pointer-to-base is being performed. */
118 BOOL_BITFIELD base_p : 1;
119 /* If KIND is ck_ref_bind, true when either an lvalue reference is
120 being bound to an lvalue expression or an rvalue reference is
121 being bound to an rvalue expression. If KIND is ck_rvalue,
122 true when we should treat an lvalue as an rvalue (12.8p33). If
123 KIND is ck_base, always false. */
124 BOOL_BITFIELD rvaluedness_matches_p: 1;
125 BOOL_BITFIELD check_narrowing: 1;
126 /* The type of the expression resulting from the conversion. */
129 /* The next conversion in the chain. Since the conversions are
130 arranged from outermost to innermost, the NEXT conversion will
131 actually be performed before this conversion. This variant is
132 used only when KIND is neither ck_identity, ck_ambig nor
133 ck_list. Please use the next_conversion function instead
134 of using this field directly. */
136 /* The expression at the beginning of the conversion chain. This
137 variant is used only if KIND is ck_identity or ck_ambig. */
139 /* The array of conversions for an initializer_list, so this
140 variant is used only when KIN D is ck_list. */
143 /* The function candidate corresponding to this conversion
144 sequence. This field is only used if KIND is ck_user. */
145 struct z_candidate *cand;
148 #define CONVERSION_RANK(NODE) \
149 ((NODE)->bad_p ? cr_bad \
150 : (NODE)->ellipsis_p ? cr_ellipsis \
151 : (NODE)->user_conv_p ? cr_user \
154 #define BAD_CONVERSION_RANK(NODE) \
155 ((NODE)->ellipsis_p ? cr_ellipsis \
156 : (NODE)->user_conv_p ? cr_user \
159 static struct obstack conversion_obstack;
160 static bool conversion_obstack_initialized;
161 struct rejection_reason;
163 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t);
164 static int equal_functions (tree, tree);
165 static int joust (struct z_candidate *, struct z_candidate *, bool,
167 static int compare_ics (conversion *, conversion *);
168 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
169 static tree build_java_interface_fn_ref (tree, tree);
170 #define convert_like(CONV, EXPR, COMPLAIN) \
171 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
172 /*issue_conversion_warnings=*/true, \
173 /*c_cast_p=*/false, (COMPLAIN))
174 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
175 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
176 /*issue_conversion_warnings=*/true, \
177 /*c_cast_p=*/false, (COMPLAIN))
178 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
179 bool, tsubst_flags_t);
180 static void op_error (location_t, enum tree_code, enum tree_code, tree,
182 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int,
184 static void print_z_candidate (location_t, const char *, struct z_candidate *);
185 static void print_z_candidates (location_t, struct z_candidate *);
186 static tree build_this (tree);
187 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
188 static bool any_strictly_viable (struct z_candidate *);
189 static struct z_candidate *add_template_candidate
190 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
191 tree, tree, tree, int, unification_kind_t, tsubst_flags_t);
192 static struct z_candidate *add_template_candidate_real
193 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
194 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t);
195 static struct z_candidate *add_template_conv_candidate
196 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *,
197 tree, tree, tree, tsubst_flags_t);
198 static void add_builtin_candidates
199 (struct z_candidate **, enum tree_code, enum tree_code,
200 tree, tree *, int, tsubst_flags_t);
201 static void add_builtin_candidate
202 (struct z_candidate **, enum tree_code, enum tree_code,
203 tree, tree, tree, tree *, tree *, int, tsubst_flags_t);
204 static bool is_complete (tree);
205 static void build_builtin_candidate
206 (struct z_candidate **, tree, tree, tree, tree *, tree *,
207 int, tsubst_flags_t);
208 static struct z_candidate *add_conv_candidate
209 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree,
210 tree, tsubst_flags_t);
211 static struct z_candidate *add_function_candidate
212 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree,
213 tree, int, tsubst_flags_t);
214 static conversion *implicit_conversion (tree, tree, tree, bool, int,
216 static conversion *reference_binding (tree, tree, tree, bool, int,
218 static conversion *build_conv (conversion_kind, tree, conversion *);
219 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t);
220 static conversion *next_conversion (conversion *);
221 static bool is_subseq (conversion *, conversion *);
222 static conversion *maybe_handle_ref_bind (conversion **);
223 static void maybe_handle_implicit_object (conversion **);
224 static struct z_candidate *add_candidate
225 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t,
226 conversion **, tree, tree, int, struct rejection_reason *, int);
227 static tree source_type (conversion *);
228 static void add_warning (struct z_candidate *, struct z_candidate *);
229 static bool reference_compatible_p (tree, tree);
230 static conversion *direct_reference_binding (tree, conversion *);
231 static bool promoted_arithmetic_type_p (tree);
232 static conversion *conditional_conversion (tree, tree, tsubst_flags_t);
233 static char *name_as_c_string (tree, tree, bool *);
234 static tree prep_operand (tree);
235 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree,
236 bool, tree, tree, int, struct z_candidate **,
238 static conversion *merge_conversion_sequences (conversion *, conversion *);
239 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
241 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
242 NAME can take many forms... */
245 check_dtor_name (tree basetype, tree name)
247 /* Just accept something we've already complained about. */
248 if (name == error_mark_node)
251 if (TREE_CODE (name) == TYPE_DECL)
252 name = TREE_TYPE (name);
253 else if (TYPE_P (name))
255 else if (identifier_p (name))
257 if ((MAYBE_CLASS_TYPE_P (basetype)
258 && name == constructor_name (basetype))
259 || (TREE_CODE (basetype) == ENUMERAL_TYPE
260 && name == TYPE_IDENTIFIER (basetype)))
263 name = get_type_value (name);
269 template <class T> struct S { ~S(); };
273 NAME will be a class template. */
274 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
278 if (!name || name == error_mark_node)
280 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
283 /* We want the address of a function or method. We avoid creating a
284 pointer-to-member function. */
287 build_addr_func (tree function, tsubst_flags_t complain)
289 tree type = TREE_TYPE (function);
291 /* We have to do these by hand to avoid real pointer to member
293 if (TREE_CODE (type) == METHOD_TYPE)
295 if (TREE_CODE (function) == OFFSET_REF)
297 tree object = build_address (TREE_OPERAND (function, 0));
298 return get_member_function_from_ptrfunc (&object,
299 TREE_OPERAND (function, 1),
302 function = build_address (function);
305 function = decay_conversion (function, complain);
310 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
311 POINTER_TYPE to those. Note, pointer to member function types
312 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
313 two variants. build_call_a is the primitive taking an array of
314 arguments, while build_call_n is a wrapper that handles varargs. */
317 build_call_n (tree function, int n, ...)
320 return build_call_a (function, 0, NULL);
323 tree *argarray = XALLOCAVEC (tree, n);
328 for (i = 0; i < n; i++)
329 argarray[i] = va_arg (ap, tree);
331 return build_call_a (function, n, argarray);
335 /* Update various flags in cfun and the call itself based on what is being
336 called. Split out of build_call_a so that bot_manip can use it too. */
339 set_flags_from_callee (tree call)
342 tree decl = get_callee_fndecl (call);
344 /* We check both the decl and the type; a function may be known not to
345 throw without being declared throw(). */
346 nothrow = decl && TREE_NOTHROW (decl);
347 if (CALL_EXPR_FN (call))
348 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call))));
349 else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW)
352 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain)
353 cp_function_chain->can_throw = 1;
355 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
356 current_function_returns_abnormally = 1;
358 TREE_NOTHROW (call) = nothrow;
362 build_call_a (tree function, int n, tree *argarray)
369 function = build_addr_func (function, tf_warning_or_error);
371 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
372 fntype = TREE_TYPE (TREE_TYPE (function));
373 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
374 || TREE_CODE (fntype) == METHOD_TYPE);
375 result_type = TREE_TYPE (fntype);
376 /* An rvalue has no cv-qualifiers. */
377 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
378 result_type = cv_unqualified (result_type);
380 function = build_call_array_loc (input_location,
381 result_type, function, n, argarray);
382 set_flags_from_callee (function);
384 decl = get_callee_fndecl (function);
386 if (decl && !TREE_USED (decl))
388 /* We invoke build_call directly for several library
389 functions. These may have been declared normally if
390 we're building libgcc, so we can't just check
392 gcc_assert (DECL_ARTIFICIAL (decl)
393 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
398 require_complete_eh_spec_types (fntype, decl);
400 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl));
402 /* Don't pass empty class objects by value. This is useful
403 for tags in STL, which are used to control overload resolution.
404 We don't need to handle other cases of copying empty classes. */
405 if (! decl || ! DECL_BUILT_IN (decl))
406 for (i = 0; i < n; i++)
408 tree arg = CALL_EXPR_ARG (function, i);
409 if (is_empty_class (TREE_TYPE (arg))
410 && ! TREE_ADDRESSABLE (TREE_TYPE (arg)))
412 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg));
413 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t);
414 CALL_EXPR_ARG (function, i) = arg;
421 /* Build something of the form ptr->method (args)
422 or object.method (args). This can also build
423 calls to constructors, and find friends.
425 Member functions always take their class variable
428 INSTANCE is a class instance.
430 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
432 PARMS help to figure out what that NAME really refers to.
434 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
435 down to the real instance type to use for access checking. We need this
436 information to get protected accesses correct.
438 FLAGS is the logical disjunction of zero or more LOOKUP_
439 flags. See cp-tree.h for more info.
441 If this is all OK, calls build_function_call with the resolved
444 This function must also handle being called to perform
445 initialization, promotion/coercion of arguments, and
446 instantiation of default parameters.
448 Note that NAME may refer to an instance variable name. If
449 `operator()()' is defined for the type of that field, then we return
452 /* New overloading code. */
454 typedef struct z_candidate z_candidate;
456 typedef struct candidate_warning candidate_warning;
457 struct candidate_warning {
459 candidate_warning *next;
462 /* Information for providing diagnostics about why overloading failed. */
464 enum rejection_reason_code {
467 rr_explicit_conversion,
468 rr_template_conversion,
470 rr_bad_arg_conversion,
471 rr_template_unification,
475 struct conversion_info {
476 /* The index of the argument, 0-based. */
478 /* The actual argument or its type. */
480 /* The type of the parameter. */
484 struct rejection_reason {
485 enum rejection_reason_code code;
487 /* Information about an arity mismatch. */
489 /* The expected number of arguments. */
491 /* The actual number of arguments in the call. */
493 /* Whether the call was a varargs call. */
496 /* Information about an argument conversion mismatch. */
497 struct conversion_info conversion;
498 /* Same, but for bad argument conversions. */
499 struct conversion_info bad_conversion;
500 /* Information about template unification failures. These are the
501 parameters passed to fn_type_unification. */
509 unification_kind_t strict;
511 } template_unification;
512 /* Information about template instantiation failures. These are the
513 parameters passed to instantiate_template. */
517 } template_instantiation;
522 /* The FUNCTION_DECL that will be called if this candidate is
523 selected by overload resolution. */
525 /* If not NULL_TREE, the first argument to use when calling this
528 /* The rest of the arguments to use when calling this function. If
529 there are no further arguments this may be NULL or it may be an
531 const vec<tree, va_gc> *args;
532 /* The implicit conversion sequences for each of the arguments to
535 /* The number of implicit conversion sequences. */
537 /* If FN is a user-defined conversion, the standard conversion
538 sequence from the type returned by FN to the desired destination
540 conversion *second_conv;
541 struct rejection_reason *reason;
542 /* If FN is a member function, the binfo indicating the path used to
543 qualify the name of FN at the call site. This path is used to
544 determine whether or not FN is accessible if it is selected by
545 overload resolution. The DECL_CONTEXT of FN will always be a
546 (possibly improper) base of this binfo. */
548 /* If FN is a non-static member function, the binfo indicating the
549 subobject to which the `this' pointer should be converted if FN
550 is selected by overload resolution. The type pointed to by
551 the `this' pointer must correspond to the most derived class
552 indicated by the CONVERSION_PATH. */
553 tree conversion_path;
556 candidate_warning *warnings;
560 /* The flags active in add_candidate. */
564 /* Returns true iff T is a null pointer constant in the sense of
568 null_ptr_cst_p (tree t)
572 A null pointer constant is an integral constant expression
573 (_expr.const_) rvalue of integer type that evaluates to zero or
574 an rvalue of type std::nullptr_t. */
575 if (NULLPTR_TYPE_P (TREE_TYPE (t)))
577 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)))
579 /* Core issue 903 says only literal 0 is a null pointer constant. */
580 if (cxx_dialect < cxx11)
581 t = fold_non_dependent_expr (t);
583 if (integer_zerop (t) && !TREE_OVERFLOW (t))
589 /* Returns true iff T is a null member pointer value (4.11). */
592 null_member_pointer_value_p (tree t)
594 tree type = TREE_TYPE (t);
597 else if (TYPE_PTRMEMFUNC_P (type))
598 return (TREE_CODE (t) == CONSTRUCTOR
599 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value));
600 else if (TYPE_PTRDATAMEM_P (type))
601 return integer_all_onesp (t);
606 /* Returns nonzero if PARMLIST consists of only default parms,
607 ellipsis, and/or undeduced parameter packs. */
610 sufficient_parms_p (const_tree parmlist)
612 for (; parmlist && parmlist != void_list_node;
613 parmlist = TREE_CHAIN (parmlist))
614 if (!TREE_PURPOSE (parmlist)
615 && !PACK_EXPANSION_P (TREE_VALUE (parmlist)))
620 /* Allocate N bytes of memory from the conversion obstack. The memory
621 is zeroed before being returned. */
624 conversion_obstack_alloc (size_t n)
627 if (!conversion_obstack_initialized)
629 gcc_obstack_init (&conversion_obstack);
630 conversion_obstack_initialized = true;
632 p = obstack_alloc (&conversion_obstack, n);
637 /* Allocate rejection reasons. */
639 static struct rejection_reason *
640 alloc_rejection (enum rejection_reason_code code)
642 struct rejection_reason *p;
643 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
648 static struct rejection_reason *
649 arity_rejection (tree first_arg, int expected, int actual)
651 struct rejection_reason *r = alloc_rejection (rr_arity);
652 int adjust = first_arg != NULL_TREE;
653 r->u.arity.expected = expected - adjust;
654 r->u.arity.actual = actual - adjust;
658 static struct rejection_reason *
659 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
661 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
662 int adjust = first_arg != NULL_TREE;
663 r->u.conversion.n_arg = n_arg - adjust;
664 r->u.conversion.from = from;
665 r->u.conversion.to_type = to;
669 static struct rejection_reason *
670 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
672 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
673 int adjust = first_arg != NULL_TREE;
674 r->u.bad_conversion.n_arg = n_arg - adjust;
675 r->u.bad_conversion.from = from;
676 r->u.bad_conversion.to_type = to;
680 static struct rejection_reason *
681 explicit_conversion_rejection (tree from, tree to)
683 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion);
684 r->u.conversion.n_arg = 0;
685 r->u.conversion.from = from;
686 r->u.conversion.to_type = to;
690 static struct rejection_reason *
691 template_conversion_rejection (tree from, tree to)
693 struct rejection_reason *r = alloc_rejection (rr_template_conversion);
694 r->u.conversion.n_arg = 0;
695 r->u.conversion.from = from;
696 r->u.conversion.to_type = to;
700 static struct rejection_reason *
701 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs,
702 const tree *args, unsigned int nargs,
703 tree return_type, unification_kind_t strict,
706 size_t args_n_bytes = sizeof (*args) * nargs;
707 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes);
708 struct rejection_reason *r = alloc_rejection (rr_template_unification);
709 r->u.template_unification.tmpl = tmpl;
710 r->u.template_unification.explicit_targs = explicit_targs;
711 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs);
712 /* Copy args to our own storage. */
713 memcpy (args1, args, args_n_bytes);
714 r->u.template_unification.args = args1;
715 r->u.template_unification.nargs = nargs;
716 r->u.template_unification.return_type = return_type;
717 r->u.template_unification.strict = strict;
718 r->u.template_unification.flags = flags;
722 static struct rejection_reason *
723 template_unification_error_rejection (void)
725 return alloc_rejection (rr_template_unification);
728 static struct rejection_reason *
729 invalid_copy_with_fn_template_rejection (void)
731 struct rejection_reason *r = alloc_rejection (rr_invalid_copy);
735 /* Dynamically allocate a conversion. */
738 alloc_conversion (conversion_kind kind)
741 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
746 #ifdef ENABLE_CHECKING
748 /* Make sure that all memory on the conversion obstack has been
752 validate_conversion_obstack (void)
754 if (conversion_obstack_initialized)
755 gcc_assert ((obstack_next_free (&conversion_obstack)
756 == obstack_base (&conversion_obstack)));
759 #endif /* ENABLE_CHECKING */
761 /* Dynamically allocate an array of N conversions. */
764 alloc_conversions (size_t n)
766 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
770 build_conv (conversion_kind code, tree type, conversion *from)
773 conversion_rank rank = CONVERSION_RANK (from);
775 /* Note that the caller is responsible for filling in t->cand for
776 user-defined conversions. */
777 t = alloc_conversion (code);
800 t->user_conv_p = (code == ck_user || from->user_conv_p);
801 t->bad_p = from->bad_p;
806 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
807 specialization of std::initializer_list<T>, if such a conversion is
811 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
813 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
814 unsigned len = CONSTRUCTOR_NELTS (ctor);
815 conversion **subconvs = alloc_conversions (len);
820 /* Within a list-initialization we can have more user-defined
822 flags &= ~LOOKUP_NO_CONVERSION;
823 /* But no narrowing conversions. */
824 flags |= LOOKUP_NO_NARROWING;
826 /* Can't make an array of these types. */
827 if (TREE_CODE (elttype) == REFERENCE_TYPE
828 || TREE_CODE (elttype) == FUNCTION_TYPE
829 || VOID_TYPE_P (elttype))
832 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
835 = implicit_conversion (elttype, TREE_TYPE (val), val,
836 false, flags, complain);
843 t = alloc_conversion (ck_list);
845 t->u.list = subconvs;
848 for (i = 0; i < len; ++i)
850 conversion *sub = subconvs[i];
851 if (sub->rank > t->rank)
853 if (sub->user_conv_p)
854 t->user_conv_p = true;
862 /* Return the next conversion of the conversion chain (if applicable),
863 or NULL otherwise. Please use this function instead of directly
864 accessing fields of struct conversion. */
867 next_conversion (conversion *conv)
870 || conv->kind == ck_identity
871 || conv->kind == ck_ambig
872 || conv->kind == ck_list)
877 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
878 is a valid aggregate initializer for array type ATYPE. */
881 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain)
884 tree elttype = TREE_TYPE (atype);
885 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
887 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
889 if (TREE_CODE (elttype) == ARRAY_TYPE
890 && TREE_CODE (val) == CONSTRUCTOR)
891 ok = can_convert_array (elttype, val, flags, complain);
893 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags,
901 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
902 aggregate class, if such a conversion is possible. */
905 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
907 unsigned HOST_WIDE_INT i = 0;
909 tree field = next_initializable_field (TYPE_FIELDS (type));
910 tree empty_ctor = NULL_TREE;
912 /* We already called reshape_init in implicit_conversion. */
914 /* The conversions within the init-list aren't affected by the enclosing
915 context; they're always simple copy-initialization. */
916 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
918 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
920 tree ftype = TREE_TYPE (field);
924 if (i < CONSTRUCTOR_NELTS (ctor))
925 val = CONSTRUCTOR_ELT (ctor, i)->value;
926 else if (DECL_INITIAL (field))
927 val = get_nsdmi (field, /*ctor*/false);
928 else if (TREE_CODE (ftype) == REFERENCE_TYPE)
929 /* Value-initialization of reference is ill-formed. */
933 if (empty_ctor == NULL_TREE)
934 empty_ctor = build_constructor (init_list_type_node, NULL);
939 if (TREE_CODE (ftype) == ARRAY_TYPE
940 && TREE_CODE (val) == CONSTRUCTOR)
941 ok = can_convert_array (ftype, val, flags, complain);
943 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags,
949 if (TREE_CODE (type) == UNION_TYPE)
953 if (i < CONSTRUCTOR_NELTS (ctor))
956 c = alloc_conversion (ck_aggr);
959 c->user_conv_p = true;
960 c->check_narrowing = true;
965 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
966 array type, if such a conversion is possible. */
969 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
972 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
973 tree elttype = TREE_TYPE (type);
978 enum conversion_rank rank = cr_exact;
980 /* We might need to propagate the size from the element to the array. */
981 complete_type (type);
983 if (TYPE_DOMAIN (type)
984 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE))
986 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type));
991 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
993 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
996 = implicit_conversion (elttype, TREE_TYPE (val), val,
997 false, flags, complain);
1001 if (sub->rank > rank)
1003 if (sub->user_conv_p)
1009 c = alloc_conversion (ck_aggr);
1012 c->user_conv_p = user;
1018 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
1019 complex type, if such a conversion is possible. */
1022 build_complex_conv (tree type, tree ctor, int flags,
1023 tsubst_flags_t complain)
1026 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
1027 tree elttype = TREE_TYPE (type);
1032 enum conversion_rank rank = cr_exact;
1037 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
1039 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
1042 = implicit_conversion (elttype, TREE_TYPE (val), val,
1043 false, flags, complain);
1047 if (sub->rank > rank)
1049 if (sub->user_conv_p)
1055 c = alloc_conversion (ck_aggr);
1058 c->user_conv_p = user;
1064 /* Build a representation of the identity conversion from EXPR to
1065 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
1068 build_identity_conv (tree type, tree expr)
1072 c = alloc_conversion (ck_identity);
1079 /* Converting from EXPR to TYPE was ambiguous in the sense that there
1080 were multiple user-defined conversions to accomplish the job.
1081 Build a conversion that indicates that ambiguity. */
1084 build_ambiguous_conv (tree type, tree expr)
1088 c = alloc_conversion (ck_ambig);
1096 strip_top_quals (tree t)
1098 if (TREE_CODE (t) == ARRAY_TYPE)
1100 return cp_build_qualified_type (t, 0);
1103 /* Returns the standard conversion path (see [conv]) from type FROM to type
1104 TO, if any. For proper handling of null pointer constants, you must
1105 also pass the expression EXPR to convert from. If C_CAST_P is true,
1106 this conversion is coming from a C-style cast. */
1109 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
1110 int flags, tsubst_flags_t complain)
1112 enum tree_code fcode, tcode;
1114 bool fromref = false;
1117 to = non_reference (to);
1118 if (TREE_CODE (from) == REFERENCE_TYPE)
1121 from = TREE_TYPE (from);
1124 to = strip_top_quals (to);
1125 from = strip_top_quals (from);
1127 if (expr && type_unknown_p (expr))
1129 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
1131 tsubst_flags_t tflags = tf_conv;
1132 expr = instantiate_type (to, expr, tflags);
1133 if (expr == error_mark_node)
1135 from = TREE_TYPE (expr);
1137 else if (TREE_CODE (to) == BOOLEAN_TYPE)
1139 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */
1140 expr = resolve_nondeduced_context (expr, complain);
1141 from = TREE_TYPE (expr);
1145 fcode = TREE_CODE (from);
1146 tcode = TREE_CODE (to);
1148 conv = build_identity_conv (from, expr);
1149 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
1151 from = type_decays_to (from);
1152 fcode = TREE_CODE (from);
1153 conv = build_conv (ck_lvalue, from, conv);
1155 else if (fromref || (expr && lvalue_p (expr)))
1160 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
1163 from = strip_top_quals (bitfield_type);
1164 fcode = TREE_CODE (from);
1167 conv = build_conv (ck_rvalue, from, conv);
1168 if (flags & LOOKUP_PREFER_RVALUE)
1169 conv->rvaluedness_matches_p = true;
1172 /* Allow conversion between `__complex__' data types. */
1173 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
1175 /* The standard conversion sequence to convert FROM to TO is
1176 the standard conversion sequence to perform componentwise
1178 conversion *part_conv = standard_conversion
1179 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags,
1184 conv = build_conv (part_conv->kind, to, conv);
1185 conv->rank = part_conv->rank;
1193 if (same_type_p (from, to))
1195 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
1196 conv->type = qualified_to;
1201 A null pointer constant can be converted to a pointer type; ... A
1202 null pointer constant of integral type can be converted to an
1203 rvalue of type std::nullptr_t. */
1204 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to)
1205 || NULLPTR_TYPE_P (to))
1206 && ((expr && null_ptr_cst_p (expr))
1207 || NULLPTR_TYPE_P (from)))
1208 conv = build_conv (ck_std, to, conv);
1209 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
1210 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
1212 /* For backwards brain damage compatibility, allow interconversion of
1213 pointers and integers with a pedwarn. */
1214 conv = build_conv (ck_std, to, conv);
1217 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
1219 /* For backwards brain damage compatibility, allow interconversion of
1220 enums and integers with a pedwarn. */
1221 conv = build_conv (ck_std, to, conv);
1224 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1225 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from)))
1230 if (tcode == POINTER_TYPE
1231 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
1234 else if (VOID_TYPE_P (TREE_TYPE (to))
1235 && !TYPE_PTRDATAMEM_P (from)
1236 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
1238 tree nfrom = TREE_TYPE (from);
1239 /* Don't try to apply restrict to void. */
1240 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT;
1241 from = build_pointer_type
1242 (cp_build_qualified_type (void_type_node, quals));
1243 conv = build_conv (ck_ptr, from, conv);
1245 else if (TYPE_PTRDATAMEM_P (from))
1247 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1248 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1250 if (DERIVED_FROM_P (fbase, tbase)
1251 && (same_type_ignoring_top_level_qualifiers_p
1252 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
1253 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
1255 from = build_ptrmem_type (tbase,
1256 TYPE_PTRMEM_POINTED_TO_TYPE (from));
1257 conv = build_conv (ck_pmem, from, conv);
1259 else if (!same_type_p (fbase, tbase))
1262 else if (CLASS_TYPE_P (TREE_TYPE (from))
1263 && CLASS_TYPE_P (TREE_TYPE (to))
1266 An rvalue of type "pointer to cv D," where D is a
1267 class type, can be converted to an rvalue of type
1268 "pointer to cv B," where B is a base class (clause
1269 _class.derived_) of D. If B is an inaccessible
1270 (clause _class.access_) or ambiguous
1271 (_class.member.lookup_) base class of D, a program
1272 that necessitates this conversion is ill-formed.
1273 Therefore, we use DERIVED_FROM_P, and do not check
1274 access or uniqueness. */
1275 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
1278 cp_build_qualified_type (TREE_TYPE (to),
1279 cp_type_quals (TREE_TYPE (from)));
1280 from = build_pointer_type (from);
1281 conv = build_conv (ck_ptr, from, conv);
1282 conv->base_p = true;
1285 if (tcode == POINTER_TYPE)
1287 to_pointee = TREE_TYPE (to);
1288 from_pointee = TREE_TYPE (from);
1292 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1293 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1296 if (same_type_p (from, to))
1298 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1299 /* In a C-style cast, we ignore CV-qualification because we
1300 are allowed to perform a static_cast followed by a
1302 conv = build_conv (ck_qual, to, conv);
1303 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1304 conv = build_conv (ck_qual, to, conv);
1305 else if (expr && string_conv_p (to, expr, 0))
1306 /* converting from string constant to char *. */
1307 conv = build_conv (ck_qual, to, conv);
1308 /* Allow conversions among compatible ObjC pointer types (base
1309 conversions have been already handled above). */
1310 else if (c_dialect_objc ()
1311 && objc_compare_types (to, from, -4, NULL_TREE))
1312 conv = build_conv (ck_ptr, to, conv);
1313 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1315 conv = build_conv (ck_ptr, to, conv);
1323 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1325 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1326 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1327 tree fbase = class_of_this_parm (fromfn);
1328 tree tbase = class_of_this_parm (tofn);
1330 if (!DERIVED_FROM_P (fbase, tbase)
1331 || !same_type_p (static_fn_type (fromfn),
1332 static_fn_type (tofn)))
1335 from = build_memfn_type (fromfn,
1337 cp_type_quals (tbase),
1338 type_memfn_rqual (tofn));
1339 from = build_ptrmemfunc_type (build_pointer_type (from));
1340 conv = build_conv (ck_pmem, from, conv);
1341 conv->base_p = true;
1343 else if (tcode == BOOLEAN_TYPE)
1347 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer
1348 to member type can be converted to a prvalue of type bool. ...
1349 For direct-initialization (8.5 [dcl.init]), a prvalue of type
1350 std::nullptr_t can be converted to a prvalue of type bool; */
1351 if (ARITHMETIC_TYPE_P (from)
1352 || UNSCOPED_ENUM_P (from)
1353 || fcode == POINTER_TYPE
1354 || TYPE_PTRMEM_P (from)
1355 || NULLPTR_TYPE_P (from))
1357 conv = build_conv (ck_std, to, conv);
1358 if (fcode == POINTER_TYPE
1359 || TYPE_PTRDATAMEM_P (from)
1360 || (TYPE_PTRMEMFUNC_P (from)
1361 && conv->rank < cr_pbool)
1362 || NULLPTR_TYPE_P (from))
1363 conv->rank = cr_pbool;
1364 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING))
1371 /* We don't check for ENUMERAL_TYPE here because there are no standard
1372 conversions to enum type. */
1373 /* As an extension, allow conversion to complex type. */
1374 else if (ARITHMETIC_TYPE_P (to))
1376 if (! (INTEGRAL_CODE_P (fcode)
1377 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL)))
1378 || SCOPED_ENUM_P (from))
1380 conv = build_conv (ck_std, to, conv);
1382 /* Give this a better rank if it's a promotion. */
1383 if (same_type_p (to, type_promotes_to (from))
1384 && next_conversion (conv)->rank <= cr_promotion)
1385 conv->rank = cr_promotion;
1387 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1388 && vector_types_convertible_p (from, to, false))
1389 return build_conv (ck_std, to, conv);
1390 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1391 && is_properly_derived_from (from, to))
1393 if (conv->kind == ck_rvalue)
1394 conv = next_conversion (conv);
1395 conv = build_conv (ck_base, to, conv);
1396 /* The derived-to-base conversion indicates the initialization
1397 of a parameter with base type from an object of a derived
1398 type. A temporary object is created to hold the result of
1399 the conversion unless we're binding directly to a reference. */
1400 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1405 if (flags & LOOKUP_NO_NARROWING)
1406 conv->check_narrowing = true;
1411 /* Returns nonzero if T1 is reference-related to T2. */
1414 reference_related_p (tree t1, tree t2)
1416 if (t1 == error_mark_node || t2 == error_mark_node)
1419 t1 = TYPE_MAIN_VARIANT (t1);
1420 t2 = TYPE_MAIN_VARIANT (t2);
1424 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1425 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1427 return (same_type_p (t1, t2)
1428 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1429 && DERIVED_FROM_P (t1, t2)));
1432 /* Returns nonzero if T1 is reference-compatible with T2. */
1435 reference_compatible_p (tree t1, tree t2)
1439 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1440 reference-related to T2 and cv1 is the same cv-qualification as,
1441 or greater cv-qualification than, cv2. */
1442 return (reference_related_p (t1, t2)
1443 && at_least_as_qualified_p (t1, t2));
1446 /* A reference of the indicated TYPE is being bound directly to the
1447 expression represented by the implicit conversion sequence CONV.
1448 Return a conversion sequence for this binding. */
1451 direct_reference_binding (tree type, conversion *conv)
1455 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1456 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1458 t = TREE_TYPE (type);
1462 When a parameter of reference type binds directly
1463 (_dcl.init.ref_) to an argument expression, the implicit
1464 conversion sequence is the identity conversion, unless the
1465 argument expression has a type that is a derived class of the
1466 parameter type, in which case the implicit conversion sequence is
1467 a derived-to-base Conversion.
1469 If the parameter binds directly to the result of applying a
1470 conversion function to the argument expression, the implicit
1471 conversion sequence is a user-defined conversion sequence
1472 (_over.ics.user_), with the second standard conversion sequence
1473 either an identity conversion or, if the conversion function
1474 returns an entity of a type that is a derived class of the
1475 parameter type, a derived-to-base conversion. */
1476 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1478 /* Represent the derived-to-base conversion. */
1479 conv = build_conv (ck_base, t, conv);
1480 /* We will actually be binding to the base-class subobject in
1481 the derived class, so we mark this conversion appropriately.
1482 That way, convert_like knows not to generate a temporary. */
1483 conv->need_temporary_p = false;
1485 return build_conv (ck_ref_bind, type, conv);
1488 /* Returns the conversion path from type FROM to reference type TO for
1489 purposes of reference binding. For lvalue binding, either pass a
1490 reference type to FROM or an lvalue expression to EXPR. If the
1491 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1492 the conversion returned. If C_CAST_P is true, this
1493 conversion is coming from a C-style cast. */
1496 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags,
1497 tsubst_flags_t complain)
1499 conversion *conv = NULL;
1500 tree to = TREE_TYPE (rto);
1505 cp_lvalue_kind gl_kind;
1508 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1510 expr = instantiate_type (to, expr, tf_none);
1511 if (expr == error_mark_node)
1513 from = TREE_TYPE (expr);
1516 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1518 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1519 /* DR 1288: Otherwise, if the initializer list has a single element
1520 of type E and ... [T's] referenced type is reference-related to E,
1521 the object or reference is initialized from that element... */
1522 if (CONSTRUCTOR_NELTS (expr) == 1)
1524 tree elt = CONSTRUCTOR_ELT (expr, 0)->value;
1525 if (error_operand_p (elt))
1527 tree etype = TREE_TYPE (elt);
1528 if (reference_related_p (to, etype))
1535 /* Otherwise, if T is a reference type, a prvalue temporary of the
1536 type referenced by T is copy-list-initialized or
1537 direct-list-initialized, depending on the kind of initialization
1538 for the reference, and the reference is bound to that temporary. */
1539 conv = implicit_conversion (to, from, expr, c_cast_p,
1540 flags|LOOKUP_NO_TEMP_BIND, complain);
1544 if (TREE_CODE (from) == REFERENCE_TYPE)
1546 from = TREE_TYPE (from);
1547 if (!TYPE_REF_IS_RVALUE (rfrom)
1548 || TREE_CODE (from) == FUNCTION_TYPE)
1549 gl_kind = clk_ordinary;
1551 gl_kind = clk_rvalueref;
1555 gl_kind = lvalue_kind (expr);
1556 if (gl_kind & clk_class)
1557 /* A class prvalue is not a glvalue. */
1562 is_lvalue = gl_kind && !(gl_kind & clk_rvalueref);
1565 if ((gl_kind & clk_bitfield) != 0)
1566 tfrom = unlowered_expr_type (expr);
1568 /* Figure out whether or not the types are reference-related and
1569 reference compatible. We have do do this after stripping
1570 references from FROM. */
1571 related_p = reference_related_p (to, tfrom);
1572 /* If this is a C cast, first convert to an appropriately qualified
1573 type, so that we can later do a const_cast to the desired type. */
1574 if (related_p && c_cast_p
1575 && !at_least_as_qualified_p (to, tfrom))
1576 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1577 compatible_p = reference_compatible_p (to, tfrom);
1579 /* Directly bind reference when target expression's type is compatible with
1580 the reference and expression is an lvalue. In DR391, the wording in
1581 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1582 const and rvalue references to rvalues of compatible class type.
1583 We should also do direct bindings for non-class xvalues. */
1586 || (!(flags & LOOKUP_NO_TEMP_BIND)
1587 && (CLASS_TYPE_P (from)
1588 || TREE_CODE (from) == ARRAY_TYPE))))
1592 If the initializer expression
1594 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1595 is reference-compatible with "cv2 T2,"
1597 the reference is bound directly to the initializer expression
1601 If the initializer expression is an rvalue, with T2 a class type,
1602 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1603 is bound to the object represented by the rvalue or to a sub-object
1604 within that object. */
1606 conv = build_identity_conv (tfrom, expr);
1607 conv = direct_reference_binding (rto, conv);
1609 if (flags & LOOKUP_PREFER_RVALUE)
1610 /* The top-level caller requested that we pretend that the lvalue
1611 be treated as an rvalue. */
1612 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1613 else if (TREE_CODE (rfrom) == REFERENCE_TYPE)
1614 /* Handle rvalue reference to function properly. */
1615 conv->rvaluedness_matches_p
1616 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom));
1618 conv->rvaluedness_matches_p
1619 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1621 if ((gl_kind & clk_bitfield) != 0
1622 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to)))
1623 /* For the purposes of overload resolution, we ignore the fact
1624 this expression is a bitfield or packed field. (In particular,
1625 [over.ics.ref] says specifically that a function with a
1626 non-const reference parameter is viable even if the
1627 argument is a bitfield.)
1629 However, when we actually call the function we must create
1630 a temporary to which to bind the reference. If the
1631 reference is volatile, or isn't const, then we cannot make
1632 a temporary, so we just issue an error when the conversion
1634 conv->need_temporary_p = true;
1636 /* Don't allow binding of lvalues (other than function lvalues) to
1637 rvalue references. */
1638 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1639 && TREE_CODE (to) != FUNCTION_TYPE
1640 && !(flags & LOOKUP_PREFER_RVALUE))
1643 /* Nor the reverse. */
1644 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto)
1645 && (!CP_TYPE_CONST_NON_VOLATILE_P (to)
1646 || (flags & LOOKUP_NO_RVAL_BIND))
1647 && TREE_CODE (to) != FUNCTION_TYPE)
1655 /* [class.conv.fct] A conversion function is never used to convert a
1656 (possibly cv-qualified) object to the (possibly cv-qualified) same
1657 object type (or a reference to it), to a (possibly cv-qualified) base
1658 class of that type (or a reference to it).... */
1659 else if (CLASS_TYPE_P (from) && !related_p
1660 && !(flags & LOOKUP_NO_CONVERSION))
1664 If the initializer expression
1666 -- has a class type (i.e., T2 is a class type) can be
1667 implicitly converted to an lvalue of type "cv3 T3," where
1668 "cv1 T1" is reference-compatible with "cv3 T3". (this
1669 conversion is selected by enumerating the applicable
1670 conversion functions (_over.match.ref_) and choosing the
1671 best one through overload resolution. (_over.match_).
1673 the reference is bound to the lvalue result of the conversion
1674 in the second case. */
1675 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags,
1678 return cand->second_conv;
1681 /* From this point on, we conceptually need temporaries, even if we
1682 elide them. Only the cases above are "direct bindings". */
1683 if (flags & LOOKUP_NO_TEMP_BIND)
1688 When a parameter of reference type is not bound directly to an
1689 argument expression, the conversion sequence is the one required
1690 to convert the argument expression to the underlying type of the
1691 reference according to _over.best.ics_. Conceptually, this
1692 conversion sequence corresponds to copy-initializing a temporary
1693 of the underlying type with the argument expression. Any
1694 difference in top-level cv-qualification is subsumed by the
1695 initialization itself and does not constitute a conversion. */
1699 Otherwise, the reference shall be an lvalue reference to a
1700 non-volatile const type, or the reference shall be an rvalue
1703 We try below to treat this as a bad conversion to improve diagnostics,
1704 but if TO is an incomplete class, we need to reject this conversion
1705 now to avoid unnecessary instantiation. */
1706 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)
1707 && !COMPLETE_TYPE_P (to))
1710 /* We're generating a temporary now, but don't bind any more in the
1711 conversion (specifically, don't slice the temporary returned by a
1712 conversion operator). */
1713 flags |= LOOKUP_NO_TEMP_BIND;
1715 /* Core issue 899: When [copy-]initializing a temporary to be bound
1716 to the first parameter of a copy constructor (12.8) called with
1717 a single argument in the context of direct-initialization,
1718 explicit conversion functions are also considered.
1720 So don't set LOOKUP_ONLYCONVERTING in that case. */
1721 if (!(flags & LOOKUP_COPY_PARM))
1722 flags |= LOOKUP_ONLYCONVERTING;
1725 conv = implicit_conversion (to, from, expr, c_cast_p,
1730 if (conv->user_conv_p)
1732 /* If initializing the temporary used a conversion function,
1733 recalculate the second conversion sequence. */
1734 for (conversion *t = conv; t; t = next_conversion (t))
1735 if (t->kind == ck_user
1736 && DECL_CONV_FN_P (t->cand->fn))
1738 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn));
1739 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND;
1740 conversion *new_second
1741 = reference_binding (rto, ftype, NULL_TREE, c_cast_p,
1745 return merge_conversion_sequences (t, new_second);
1749 conv = build_conv (ck_ref_bind, rto, conv);
1750 /* This reference binding, unlike those above, requires the
1751 creation of a temporary. */
1752 conv->need_temporary_p = true;
1753 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1757 Otherwise, the reference shall be an lvalue reference to a
1758 non-volatile const type, or the reference shall be an rvalue
1760 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1765 Otherwise, a temporary of type "cv1 T1" is created and
1766 initialized from the initializer expression using the rules for a
1767 non-reference copy initialization. If T1 is reference-related to
1768 T2, cv1 must be the same cv-qualification as, or greater
1769 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1770 if (related_p && !at_least_as_qualified_p (to, from))
1776 /* Returns the implicit conversion sequence (see [over.ics]) from type
1777 FROM to type TO. The optional expression EXPR may affect the
1778 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1779 true, this conversion is coming from a C-style cast. */
1782 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1783 int flags, tsubst_flags_t complain)
1787 if (from == error_mark_node || to == error_mark_node
1788 || expr == error_mark_node)
1791 /* Other flags only apply to the primary function in overload
1792 resolution, or after we've chosen one. */
1793 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM
1794 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE
1795 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL);
1797 /* FIXME: actually we don't want warnings either, but we can't just
1798 have 'complain &= ~(tf_warning|tf_error)' because it would cause
1799 the regression of, eg, g++.old-deja/g++.benjamin/16077.C.
1800 We really ought not to issue that warning until we've committed
1801 to that conversion. */
1802 complain &= ~tf_error;
1804 /* Call reshape_init early to remove redundant braces. */
1805 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)
1806 && CLASS_TYPE_P (to)
1807 && COMPLETE_TYPE_P (complete_type (to))
1808 && !CLASSTYPE_NON_AGGREGATE (to))
1810 expr = reshape_init (to, expr, complain);
1811 if (expr == error_mark_node)
1813 from = TREE_TYPE (expr);
1816 if (TREE_CODE (to) == REFERENCE_TYPE)
1817 conv = reference_binding (to, from, expr, c_cast_p, flags, complain);
1819 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain);
1824 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1826 if (is_std_init_list (to))
1827 return build_list_conv (to, expr, flags, complain);
1829 /* As an extension, allow list-initialization of _Complex. */
1830 if (TREE_CODE (to) == COMPLEX_TYPE)
1832 conv = build_complex_conv (to, expr, flags, complain);
1837 /* Allow conversion from an initializer-list with one element to a
1839 if (SCALAR_TYPE_P (to))
1841 int nelts = CONSTRUCTOR_NELTS (expr);
1845 elt = build_value_init (to, tf_none);
1846 else if (nelts == 1)
1847 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1849 elt = error_mark_node;
1851 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1852 c_cast_p, flags, complain);
1855 conv->check_narrowing = true;
1856 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1857 /* Too many levels of braces, i.e. '{{1}}'. */
1862 else if (TREE_CODE (to) == ARRAY_TYPE)
1863 return build_array_conv (to, expr, flags, complain);
1866 if (expr != NULL_TREE
1867 && (MAYBE_CLASS_TYPE_P (from)
1868 || MAYBE_CLASS_TYPE_P (to))
1869 && (flags & LOOKUP_NO_CONVERSION) == 0)
1871 struct z_candidate *cand;
1873 if (CLASS_TYPE_P (to)
1874 && BRACE_ENCLOSED_INITIALIZER_P (expr)
1875 && !CLASSTYPE_NON_AGGREGATE (complete_type (to)))
1876 return build_aggr_conv (to, expr, flags, complain);
1878 cand = build_user_type_conversion_1 (to, expr, flags, complain);
1880 conv = cand->second_conv;
1882 /* We used to try to bind a reference to a temporary here, but that
1883 is now handled after the recursive call to this function at the end
1884 of reference_binding. */
1891 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1892 functions. ARGS will not be changed until a single candidate is
1895 static struct z_candidate *
1896 add_candidate (struct z_candidate **candidates,
1897 tree fn, tree first_arg, const vec<tree, va_gc> *args,
1898 size_t num_convs, conversion **convs,
1899 tree access_path, tree conversion_path,
1900 int viable, struct rejection_reason *reason,
1903 struct z_candidate *cand = (struct z_candidate *)
1904 conversion_obstack_alloc (sizeof (struct z_candidate));
1907 cand->first_arg = first_arg;
1909 cand->convs = convs;
1910 cand->num_convs = num_convs;
1911 cand->access_path = access_path;
1912 cand->conversion_path = conversion_path;
1913 cand->viable = viable;
1914 cand->reason = reason;
1915 cand->next = *candidates;
1916 cand->flags = flags;
1922 /* Return the number of remaining arguments in the parameter list
1923 beginning with ARG. */
1926 remaining_arguments (tree arg)
1930 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1931 arg = TREE_CHAIN (arg))
1937 /* Create an overload candidate for the function or method FN called
1938 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1939 FLAGS is passed on to implicit_conversion.
1941 This does not change ARGS.
1943 CTYPE, if non-NULL, is the type we want to pretend this function
1944 comes from for purposes of overload resolution. */
1946 static struct z_candidate *
1947 add_function_candidate (struct z_candidate **candidates,
1948 tree fn, tree ctype, tree first_arg,
1949 const vec<tree, va_gc> *args, tree access_path,
1950 tree conversion_path, int flags,
1951 tsubst_flags_t complain)
1953 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1957 tree orig_first_arg = first_arg;
1960 struct rejection_reason *reason = NULL;
1962 /* At this point we should not see any functions which haven't been
1963 explicitly declared, except for friend functions which will have
1964 been found using argument dependent lookup. */
1965 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1967 /* The `this', `in_chrg' and VTT arguments to constructors are not
1968 considered in overload resolution. */
1969 if (DECL_CONSTRUCTOR_P (fn))
1971 parmlist = skip_artificial_parms_for (fn, parmlist);
1972 skip = num_artificial_parms_for (fn);
1973 if (skip > 0 && first_arg != NULL_TREE)
1976 first_arg = NULL_TREE;
1982 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0);
1983 convs = alloc_conversions (len);
1985 /* 13.3.2 - Viable functions [over.match.viable]
1986 First, to be a viable function, a candidate function shall have enough
1987 parameters to agree in number with the arguments in the list.
1989 We need to check this first; otherwise, checking the ICSes might cause
1990 us to produce an ill-formed template instantiation. */
1992 parmnode = parmlist;
1993 for (i = 0; i < len; ++i)
1995 if (parmnode == NULL_TREE || parmnode == void_list_node)
1997 parmnode = TREE_CHAIN (parmnode);
2000 if ((i < len && parmnode)
2001 || !sufficient_parms_p (parmnode))
2003 int remaining = remaining_arguments (parmnode);
2005 reason = arity_rejection (first_arg, i + remaining, len);
2007 /* When looking for a function from a subobject from an implicit
2008 copy/move constructor/operator=, don't consider anything that takes (a
2009 reference to) an unrelated type. See c++/44909 and core 1092. */
2010 else if (parmlist && (flags & LOOKUP_DEFAULTED))
2012 if (DECL_CONSTRUCTOR_P (fn))
2014 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
2015 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
2021 parmnode = chain_index (i-1, parmlist);
2022 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
2027 /* This only applies at the top level. */
2028 flags &= ~LOOKUP_DEFAULTED;
2034 /* Second, for F to be a viable function, there shall exist for each
2035 argument an implicit conversion sequence that converts that argument
2036 to the corresponding parameter of F. */
2038 parmnode = parmlist;
2040 for (i = 0; i < len; ++i)
2042 tree argtype, to_type;
2047 if (parmnode == void_list_node)
2050 if (i == 0 && first_arg != NULL_TREE)
2053 arg = CONST_CAST_TREE (
2054 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]);
2055 argtype = lvalue_type (arg);
2057 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
2058 && ! DECL_CONSTRUCTOR_P (fn));
2062 tree parmtype = TREE_VALUE (parmnode);
2065 parmnode = TREE_CHAIN (parmnode);
2067 /* The type of the implicit object parameter ('this') for
2068 overload resolution is not always the same as for the
2069 function itself; conversion functions are considered to
2070 be members of the class being converted, and functions
2071 introduced by a using-declaration are considered to be
2072 members of the class that uses them.
2074 Since build_over_call ignores the ICS for the `this'
2075 parameter, we can just change the parm type. */
2076 if (ctype && is_this)
2078 parmtype = cp_build_qualified_type
2079 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
2080 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn)))
2082 /* If the function has a ref-qualifier, the implicit
2083 object parameter has reference type. */
2084 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
2085 parmtype = cp_build_reference_type (parmtype, rv);
2086 /* The special handling of 'this' conversions in compare_ics
2087 does not apply if there is a ref-qualifier. */
2092 parmtype = build_pointer_type (parmtype);
2093 arg = build_this (arg);
2094 argtype = lvalue_type (arg);
2098 /* Core issue 899: When [copy-]initializing a temporary to be bound
2099 to the first parameter of a copy constructor (12.8) called with
2100 a single argument in the context of direct-initialization,
2101 explicit conversion functions are also considered.
2103 So set LOOKUP_COPY_PARM to let reference_binding know that
2104 it's being called in that context. We generalize the above
2105 to handle move constructors and template constructors as well;
2106 the standardese should soon be updated similarly. */
2107 if (ctype && i == 0 && (len-skip == 1)
2108 && DECL_CONSTRUCTOR_P (fn)
2109 && parmtype != error_mark_node
2110 && (same_type_ignoring_top_level_qualifiers_p
2111 (non_reference (parmtype), ctype)))
2113 if (!(flags & LOOKUP_ONLYCONVERTING))
2114 lflags |= LOOKUP_COPY_PARM;
2115 /* We allow user-defined conversions within init-lists, but
2116 don't list-initialize the copy parm, as that would mean
2117 using two levels of braces for the same type. */
2118 if ((flags & LOOKUP_LIST_INIT_CTOR)
2119 && BRACE_ENCLOSED_INITIALIZER_P (arg))
2120 lflags |= LOOKUP_NO_CONVERSION;
2123 lflags |= LOOKUP_ONLYCONVERTING;
2125 t = implicit_conversion (parmtype, argtype, arg,
2126 /*c_cast_p=*/false, lflags, complain);
2131 t = build_identity_conv (argtype, arg);
2132 t->ellipsis_p = true;
2143 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
2150 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type);
2155 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
2156 access_path, conversion_path, viable, reason, flags);
2159 /* Create an overload candidate for the conversion function FN which will
2160 be invoked for expression OBJ, producing a pointer-to-function which
2161 will in turn be called with the argument list FIRST_ARG/ARGLIST,
2162 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
2163 passed on to implicit_conversion.
2165 Actually, we don't really care about FN; we care about the type it
2166 converts to. There may be multiple conversion functions that will
2167 convert to that type, and we rely on build_user_type_conversion_1 to
2168 choose the best one; so when we create our candidate, we record the type
2169 instead of the function. */
2171 static struct z_candidate *
2172 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
2173 tree first_arg, const vec<tree, va_gc> *arglist,
2174 tree access_path, tree conversion_path,
2175 tsubst_flags_t complain)
2177 tree totype = TREE_TYPE (TREE_TYPE (fn));
2178 int i, len, viable, flags;
2179 tree parmlist, parmnode;
2181 struct rejection_reason *reason;
2183 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
2184 parmlist = TREE_TYPE (parmlist);
2185 parmlist = TYPE_ARG_TYPES (parmlist);
2187 len = vec_safe_length (arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1;
2188 convs = alloc_conversions (len);
2189 parmnode = parmlist;
2191 flags = LOOKUP_IMPLICIT;
2194 /* Don't bother looking up the same type twice. */
2195 if (*candidates && (*candidates)->fn == totype)
2198 for (i = 0; i < len; ++i)
2200 tree arg, argtype, convert_type = NULL_TREE;
2205 else if (i == 1 && first_arg != NULL_TREE)
2208 arg = (*arglist)[i - (first_arg != NULL_TREE ? 1 : 0) - 1];
2209 argtype = lvalue_type (arg);
2213 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
2215 convert_type = totype;
2217 else if (parmnode == void_list_node)
2221 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2222 /*c_cast_p=*/false, flags, complain);
2223 convert_type = TREE_VALUE (parmnode);
2227 t = build_identity_conv (argtype, arg);
2228 t->ellipsis_p = true;
2229 convert_type = argtype;
2239 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type);
2246 parmnode = TREE_CHAIN (parmnode);
2250 || ! sufficient_parms_p (parmnode))
2252 int remaining = remaining_arguments (parmnode);
2254 reason = arity_rejection (NULL_TREE, i + remaining, len);
2257 return add_candidate (candidates, totype, first_arg, arglist, len, convs,
2258 access_path, conversion_path, viable, reason, flags);
2262 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2263 tree type1, tree type2, tree *args, tree *argtypes,
2264 int flags, tsubst_flags_t complain)
2271 struct rejection_reason *reason = NULL;
2276 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2277 convs = alloc_conversions (num_convs);
2279 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2280 conversion ops are allowed. We handle that here by just checking for
2281 boolean_type_node because other operators don't ask for it. COND_EXPR
2282 also does contextual conversion to bool for the first operand, but we
2283 handle that in build_conditional_expr, and type1 here is operand 2. */
2284 if (type1 != boolean_type_node)
2285 flags |= LOOKUP_ONLYCONVERTING;
2287 for (i = 0; i < 2; ++i)
2292 t = implicit_conversion (types[i], argtypes[i], args[i],
2293 /*c_cast_p=*/false, flags, complain);
2297 /* We need something for printing the candidate. */
2298 t = build_identity_conv (types[i], NULL_TREE);
2299 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i],
2305 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i],
2311 /* For COND_EXPR we rearranged the arguments; undo that now. */
2314 convs[2] = convs[1];
2315 convs[1] = convs[0];
2316 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2317 /*c_cast_p=*/false, flags,
2324 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2329 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2331 /*access_path=*/NULL_TREE,
2332 /*conversion_path=*/NULL_TREE,
2333 viable, reason, flags);
2337 is_complete (tree t)
2339 return COMPLETE_TYPE_P (complete_type (t));
2342 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2345 promoted_arithmetic_type_p (tree type)
2349 In this section, the term promoted integral type is used to refer
2350 to those integral types which are preserved by integral promotion
2351 (including e.g. int and long but excluding e.g. char).
2352 Similarly, the term promoted arithmetic type refers to promoted
2353 integral types plus floating types. */
2354 return ((CP_INTEGRAL_TYPE_P (type)
2355 && same_type_p (type_promotes_to (type), type))
2356 || TREE_CODE (type) == REAL_TYPE);
2359 /* Create any builtin operator overload candidates for the operator in
2360 question given the converted operand types TYPE1 and TYPE2. The other
2361 args are passed through from add_builtin_candidates to
2362 build_builtin_candidate.
2364 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2365 If CODE is requires candidates operands of the same type of the kind
2366 of which TYPE1 and TYPE2 are, we add both candidates
2367 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2370 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2371 enum tree_code code2, tree fnname, tree type1,
2372 tree type2, tree *args, tree *argtypes, int flags,
2373 tsubst_flags_t complain)
2377 case POSTINCREMENT_EXPR:
2378 case POSTDECREMENT_EXPR:
2379 args[1] = integer_zero_node;
2380 type2 = integer_type_node;
2389 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2390 and VQ is either volatile or empty, there exist candidate operator
2391 functions of the form
2392 VQ T& operator++(VQ T&);
2393 T operator++(VQ T&, int);
2394 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2395 type other than bool, and VQ is either volatile or empty, there exist
2396 candidate operator functions of the form
2397 VQ T& operator--(VQ T&);
2398 T operator--(VQ T&, int);
2399 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2400 complete object type, and VQ is either volatile or empty, there exist
2401 candidate operator functions of the form
2402 T*VQ& operator++(T*VQ&);
2403 T*VQ& operator--(T*VQ&);
2404 T* operator++(T*VQ&, int);
2405 T* operator--(T*VQ&, int); */
2407 case POSTDECREMENT_EXPR:
2408 case PREDECREMENT_EXPR:
2409 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2411 case POSTINCREMENT_EXPR:
2412 case PREINCREMENT_EXPR:
2413 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2415 type1 = build_reference_type (type1);
2420 /* 7 For every cv-qualified or cv-unqualified object type T, there
2421 exist candidate operator functions of the form
2425 8 For every function type T, there exist candidate operator functions of
2427 T& operator*(T*); */
2430 if (TYPE_PTR_P (type1)
2431 && (TYPE_PTROB_P (type1)
2432 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2436 /* 9 For every type T, there exist candidate operator functions of the form
2439 10For every promoted arithmetic type T, there exist candidate operator
2440 functions of the form
2444 case UNARY_PLUS_EXPR: /* unary + */
2445 if (TYPE_PTR_P (type1))
2448 if (ARITHMETIC_TYPE_P (type1))
2452 /* 11For every promoted integral type T, there exist candidate operator
2453 functions of the form
2457 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2461 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2462 is the same type as C2 or is a derived class of C2, T is a complete
2463 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2464 there exist candidate operator functions of the form
2465 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2466 where CV12 is the union of CV1 and CV2. */
2469 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2))
2471 tree c1 = TREE_TYPE (type1);
2472 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2474 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2475 && (TYPE_PTRMEMFUNC_P (type2)
2476 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2481 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2482 didate operator functions of the form
2487 bool operator<(L, R);
2488 bool operator>(L, R);
2489 bool operator<=(L, R);
2490 bool operator>=(L, R);
2491 bool operator==(L, R);
2492 bool operator!=(L, R);
2493 where LR is the result of the usual arithmetic conversions between
2496 14For every pair of types T and I, where T is a cv-qualified or cv-
2497 unqualified complete object type and I is a promoted integral type,
2498 there exist candidate operator functions of the form
2499 T* operator+(T*, I);
2500 T& operator[](T*, I);
2501 T* operator-(T*, I);
2502 T* operator+(I, T*);
2503 T& operator[](I, T*);
2505 15For every T, where T is a pointer to complete object type, there exist
2506 candidate operator functions of the form112)
2507 ptrdiff_t operator-(T, T);
2509 16For every pointer or enumeration type T, there exist candidate operator
2510 functions of the form
2511 bool operator<(T, T);
2512 bool operator>(T, T);
2513 bool operator<=(T, T);
2514 bool operator>=(T, T);
2515 bool operator==(T, T);
2516 bool operator!=(T, T);
2518 17For every pointer to member type T, there exist candidate operator
2519 functions of the form
2520 bool operator==(T, T);
2521 bool operator!=(T, T); */
2524 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2526 if (TYPE_PTROB_P (type1)
2527 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2529 type2 = ptrdiff_type_node;
2533 case TRUNC_DIV_EXPR:
2534 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2540 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2541 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)))
2543 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1]))
2548 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0]))
2560 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2562 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2564 if (TREE_CODE (type1) == ENUMERAL_TYPE
2565 && TREE_CODE (type2) == ENUMERAL_TYPE)
2567 if (TYPE_PTR_P (type1)
2568 && null_ptr_cst_p (args[1]))
2573 if (null_ptr_cst_p (args[0])
2574 && TYPE_PTR_P (type2))
2582 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2585 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2587 type1 = ptrdiff_type_node;
2590 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2592 type2 = ptrdiff_type_node;
2597 /* 18For every pair of promoted integral types L and R, there exist candi-
2598 date operator functions of the form
2605 where LR is the result of the usual arithmetic conversions between
2608 case TRUNC_MOD_EXPR:
2614 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2618 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2619 type, VQ is either volatile or empty, and R is a promoted arithmetic
2620 type, there exist candidate operator functions of the form
2621 VQ L& operator=(VQ L&, R);
2622 VQ L& operator*=(VQ L&, R);
2623 VQ L& operator/=(VQ L&, R);
2624 VQ L& operator+=(VQ L&, R);
2625 VQ L& operator-=(VQ L&, R);
2627 20For every pair T, VQ), where T is any type and VQ is either volatile
2628 or empty, there exist candidate operator functions of the form
2629 T*VQ& operator=(T*VQ&, T*);
2631 21For every pair T, VQ), where T is a pointer to member type and VQ is
2632 either volatile or empty, there exist candidate operator functions of
2634 VQ T& operator=(VQ T&, T);
2636 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2637 unqualified complete object type, VQ is either volatile or empty, and
2638 I is a promoted integral type, there exist candidate operator func-
2640 T*VQ& operator+=(T*VQ&, I);
2641 T*VQ& operator-=(T*VQ&, I);
2643 23For every triple L, VQ, R), where L is an integral or enumeration
2644 type, VQ is either volatile or empty, and R is a promoted integral
2645 type, there exist candidate operator functions of the form
2647 VQ L& operator%=(VQ L&, R);
2648 VQ L& operator<<=(VQ L&, R);
2649 VQ L& operator>>=(VQ L&, R);
2650 VQ L& operator&=(VQ L&, R);
2651 VQ L& operator^=(VQ L&, R);
2652 VQ L& operator|=(VQ L&, R); */
2659 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2661 type2 = ptrdiff_type_node;
2665 case TRUNC_DIV_EXPR:
2666 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2670 case TRUNC_MOD_EXPR:
2676 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2681 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2683 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2684 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2685 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2686 || ((TYPE_PTRMEMFUNC_P (type1)
2687 || TYPE_PTR_P (type1))
2688 && null_ptr_cst_p (args[1])))
2698 type1 = build_reference_type (type1);
2704 For every pair of promoted arithmetic types L and R, there
2705 exist candidate operator functions of the form
2707 LR operator?(bool, L, R);
2709 where LR is the result of the usual arithmetic conversions
2710 between types L and R.
2712 For every type T, where T is a pointer or pointer-to-member
2713 type, there exist candidate operator functions of the form T
2714 operator?(bool, T, T); */
2716 if (promoted_arithmetic_type_p (type1)
2717 && promoted_arithmetic_type_p (type2))
2721 /* Otherwise, the types should be pointers. */
2722 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2))
2725 /* We don't check that the two types are the same; the logic
2726 below will actually create two candidates; one in which both
2727 parameter types are TYPE1, and one in which both parameter
2733 if (ARITHMETIC_TYPE_P (type1))
2741 /* Make sure we don't create builtin candidates with dependent types. */
2742 bool u1 = uses_template_parms (type1);
2743 bool u2 = type2 ? uses_template_parms (type2) : false;
2746 /* Try to recover if one of the types is non-dependent. But if
2747 there's only one type, there's nothing we can do. */
2750 /* And we lose if both are dependent. */
2753 /* Or if they have different forms. */
2754 if (TREE_CODE (type1) != TREE_CODE (type2))
2763 /* If we're dealing with two pointer types or two enumeral types,
2764 we need candidates for both of them. */
2765 if (type2 && !same_type_p (type1, type2)
2766 && TREE_CODE (type1) == TREE_CODE (type2)
2767 && (TREE_CODE (type1) == REFERENCE_TYPE
2768 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2769 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2770 || TYPE_PTRMEMFUNC_P (type1)
2771 || MAYBE_CLASS_TYPE_P (type1)
2772 || TREE_CODE (type1) == ENUMERAL_TYPE))
2774 if (TYPE_PTR_OR_PTRMEM_P (type1))
2776 tree cptype = composite_pointer_type (type1, type2,
2781 if (cptype != error_mark_node)
2783 build_builtin_candidate
2784 (candidates, fnname, cptype, cptype, args, argtypes,
2790 build_builtin_candidate
2791 (candidates, fnname, type1, type1, args, argtypes, flags, complain);
2792 build_builtin_candidate
2793 (candidates, fnname, type2, type2, args, argtypes, flags, complain);
2797 build_builtin_candidate
2798 (candidates, fnname, type1, type2, args, argtypes, flags, complain);
2802 type_decays_to (tree type)
2804 if (TREE_CODE (type) == ARRAY_TYPE)
2805 return build_pointer_type (TREE_TYPE (type));
2806 if (TREE_CODE (type) == FUNCTION_TYPE)
2807 return build_pointer_type (type);
2811 /* There are three conditions of builtin candidates:
2813 1) bool-taking candidates. These are the same regardless of the input.
2814 2) pointer-pair taking candidates. These are generated for each type
2815 one of the input types converts to.
2816 3) arithmetic candidates. According to the standard, we should generate
2817 all of these, but I'm trying not to...
2819 Here we generate a superset of the possible candidates for this particular
2820 case. That is a subset of the full set the standard defines, plus some
2821 other cases which the standard disallows. add_builtin_candidate will
2822 filter out the invalid set. */
2825 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2826 enum tree_code code2, tree fnname, tree *args,
2827 int flags, tsubst_flags_t complain)
2831 tree type, argtypes[3], t;
2832 /* TYPES[i] is the set of possible builtin-operator parameter types
2833 we will consider for the Ith argument. */
2834 vec<tree, va_gc> *types[2];
2837 for (i = 0; i < 3; ++i)
2840 argtypes[i] = unlowered_expr_type (args[i]);
2842 argtypes[i] = NULL_TREE;
2847 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2848 and VQ is either volatile or empty, there exist candidate operator
2849 functions of the form
2850 VQ T& operator++(VQ T&); */
2852 case POSTINCREMENT_EXPR:
2853 case PREINCREMENT_EXPR:
2854 case POSTDECREMENT_EXPR:
2855 case PREDECREMENT_EXPR:
2860 /* 24There also exist candidate operator functions of the form
2861 bool operator!(bool);
2862 bool operator&&(bool, bool);
2863 bool operator||(bool, bool); */
2865 case TRUTH_NOT_EXPR:
2866 build_builtin_candidate
2867 (candidates, fnname, boolean_type_node,
2868 NULL_TREE, args, argtypes, flags, complain);
2871 case TRUTH_ORIF_EXPR:
2872 case TRUTH_ANDIF_EXPR:
2873 build_builtin_candidate
2874 (candidates, fnname, boolean_type_node,
2875 boolean_type_node, args, argtypes, flags, complain);
2897 types[0] = make_tree_vector ();
2898 types[1] = make_tree_vector ();
2900 for (i = 0; i < 2; ++i)
2904 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2908 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2911 convs = lookup_conversions (argtypes[i]);
2913 if (code == COND_EXPR)
2915 if (real_lvalue_p (args[i]))
2916 vec_safe_push (types[i], build_reference_type (argtypes[i]));
2918 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i]));
2924 for (; convs; convs = TREE_CHAIN (convs))
2926 type = TREE_TYPE (convs);
2929 && (TREE_CODE (type) != REFERENCE_TYPE
2930 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2933 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2934 vec_safe_push (types[i], type);
2936 type = non_reference (type);
2937 if (i != 0 || ! ref1)
2939 type = cv_unqualified (type_decays_to (type));
2940 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2941 vec_safe_push (types[i], type);
2942 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2943 type = type_promotes_to (type);
2946 if (! vec_member (type, types[i]))
2947 vec_safe_push (types[i], type);
2952 if (code == COND_EXPR && real_lvalue_p (args[i]))
2953 vec_safe_push (types[i], build_reference_type (argtypes[i]));
2954 type = non_reference (argtypes[i]);
2955 if (i != 0 || ! ref1)
2957 type = cv_unqualified (type_decays_to (type));
2958 if (enum_p && UNSCOPED_ENUM_P (type))
2959 vec_safe_push (types[i], type);
2960 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2961 type = type_promotes_to (type);
2963 vec_safe_push (types[i], type);
2967 /* Run through the possible parameter types of both arguments,
2968 creating candidates with those parameter types. */
2969 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t)
2974 if (!types[1]->is_empty ())
2975 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u)
2976 add_builtin_candidate
2977 (candidates, code, code2, fnname, t,
2978 u, args, argtypes, flags, complain);
2980 add_builtin_candidate
2981 (candidates, code, code2, fnname, t,
2982 NULL_TREE, args, argtypes, flags, complain);
2985 release_tree_vector (types[0]);
2986 release_tree_vector (types[1]);
2990 /* If TMPL can be successfully instantiated as indicated by
2991 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2993 TMPL is the template. EXPLICIT_TARGS are any explicit template
2994 arguments. ARGLIST is the arguments provided at the call-site.
2995 This does not change ARGLIST. The RETURN_TYPE is the desired type
2996 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2997 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2998 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
3000 static struct z_candidate*
3001 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
3002 tree ctype, tree explicit_targs, tree first_arg,
3003 const vec<tree, va_gc> *arglist, tree return_type,
3004 tree access_path, tree conversion_path,
3005 int flags, tree obj, unification_kind_t strict,
3006 tsubst_flags_t complain)
3008 int ntparms = DECL_NTPARMS (tmpl);
3009 tree targs = make_tree_vec (ntparms);
3010 unsigned int len = vec_safe_length (arglist);
3011 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
3012 unsigned int skip_without_in_chrg = 0;
3013 tree first_arg_without_in_chrg = first_arg;
3014 tree *args_without_in_chrg;
3015 unsigned int nargs_without_in_chrg;
3016 unsigned int ia, ix;
3018 struct z_candidate *cand;
3020 struct rejection_reason *reason = NULL;
3023 /* We don't do deduction on the in-charge parameter, the VTT
3024 parameter or 'this'. */
3025 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
3027 if (first_arg_without_in_chrg != NULL_TREE)
3028 first_arg_without_in_chrg = NULL_TREE;
3030 ++skip_without_in_chrg;
3033 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
3034 || DECL_BASE_CONSTRUCTOR_P (tmpl))
3035 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
3037 if (first_arg_without_in_chrg != NULL_TREE)
3038 first_arg_without_in_chrg = NULL_TREE;
3040 ++skip_without_in_chrg;
3043 if (len < skip_without_in_chrg)
3046 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
3047 + (len - skip_without_in_chrg));
3048 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
3050 if (first_arg_without_in_chrg != NULL_TREE)
3052 args_without_in_chrg[ia] = first_arg_without_in_chrg;
3055 for (ix = skip_without_in_chrg;
3056 vec_safe_iterate (arglist, ix, &arg);
3059 args_without_in_chrg[ia] = arg;
3062 gcc_assert (ia == nargs_without_in_chrg);
3064 errs = errorcount+sorrycount;
3065 fn = fn_type_unification (tmpl, explicit_targs, targs,
3066 args_without_in_chrg,
3067 nargs_without_in_chrg,
3068 return_type, strict, flags, false,
3069 complain & tf_decltype);
3071 if (fn == error_mark_node)
3073 /* Don't repeat unification later if it already resulted in errors. */
3074 if (errorcount+sorrycount == errs)
3075 reason = template_unification_rejection (tmpl, explicit_targs,
3076 targs, args_without_in_chrg,
3077 nargs_without_in_chrg,
3078 return_type, strict, flags);
3080 reason = template_unification_error_rejection ();
3086 A member function template is never instantiated to perform the
3087 copy of a class object to an object of its class type.
3089 It's a little unclear what this means; the standard explicitly
3090 does allow a template to be used to copy a class. For example,
3095 template <class T> A(const T&);
3098 void g () { A a (f ()); }
3100 the member template will be used to make the copy. The section
3101 quoted above appears in the paragraph that forbids constructors
3102 whose only parameter is (a possibly cv-qualified variant of) the
3103 class type, and a logical interpretation is that the intent was
3104 to forbid the instantiation of member templates which would then
3106 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
3108 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
3109 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
3112 reason = invalid_copy_with_fn_template_rejection ();
3117 if (obj != NULL_TREE)
3118 /* Aha, this is a conversion function. */
3119 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist,
3120 access_path, conversion_path, complain);
3122 cand = add_function_candidate (candidates, fn, ctype,
3123 first_arg, arglist, access_path,
3124 conversion_path, flags, complain);
3125 if (DECL_TI_TEMPLATE (fn) != tmpl)
3126 /* This situation can occur if a member template of a template
3127 class is specialized. Then, instantiate_template might return
3128 an instantiation of the specialization, in which case the
3129 DECL_TI_TEMPLATE field will point at the original
3130 specialization. For example:
3132 template <class T> struct S { template <class U> void f(U);
3133 template <> void f(int) {}; };
3137 Here, TMPL will be template <class U> S<double>::f(U).
3138 And, instantiate template will give us the specialization
3139 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
3140 for this will point at template <class T> template <> S<T>::f(int),
3141 so that we can find the definition. For the purposes of
3142 overload resolution, however, we want the original TMPL. */
3143 cand->template_decl = build_template_info (tmpl, targs);
3145 cand->template_decl = DECL_TEMPLATE_INFO (fn);
3146 cand->explicit_targs = explicit_targs;
3150 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
3151 access_path, conversion_path, 0, reason, flags);
3155 static struct z_candidate *
3156 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
3157 tree explicit_targs, tree first_arg,
3158 const vec<tree, va_gc> *arglist, tree return_type,
3159 tree access_path, tree conversion_path, int flags,
3160 unification_kind_t strict, tsubst_flags_t complain)
3163 add_template_candidate_real (candidates, tmpl, ctype,
3164 explicit_targs, first_arg, arglist,
3165 return_type, access_path, conversion_path,
3166 flags, NULL_TREE, strict, complain);
3170 static struct z_candidate *
3171 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
3172 tree obj, tree first_arg,
3173 const vec<tree, va_gc> *arglist,
3174 tree return_type, tree access_path,
3175 tree conversion_path, tsubst_flags_t complain)
3178 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
3179 first_arg, arglist, return_type, access_path,
3180 conversion_path, 0, obj, DEDUCE_CONV,
3184 /* The CANDS are the set of candidates that were considered for
3185 overload resolution. Return the set of viable candidates, or CANDS
3186 if none are viable. If any of the candidates were viable, set
3187 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3188 considered viable only if it is strictly viable. */
3190 static struct z_candidate*
3191 splice_viable (struct z_candidate *cands,
3195 struct z_candidate *viable;
3196 struct z_candidate **last_viable;
3197 struct z_candidate **cand;
3198 bool found_strictly_viable = false;
3200 /* Be strict inside templates, since build_over_call won't actually
3201 do the conversions to get pedwarns. */
3202 if (processing_template_decl)
3206 last_viable = &viable;
3207 *any_viable_p = false;
3212 struct z_candidate *c = *cand;
3214 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL))
3216 /* Be strict in the presence of a viable candidate. Also if
3217 there are template candidates, so that we get deduction errors
3218 for them instead of silently preferring a bad conversion. */
3220 if (viable && !found_strictly_viable)
3222 /* Put any spliced near matches back onto the main list so
3223 that we see them if there is no strict match. */
3224 *any_viable_p = false;
3225 *last_viable = cands;
3228 last_viable = &viable;
3232 if (strict_p ? c->viable == 1 : c->viable)
3237 last_viable = &c->next;
3238 *any_viable_p = true;
3240 found_strictly_viable = true;
3246 return viable ? viable : cands;
3250 any_strictly_viable (struct z_candidate *cands)
3252 for (; cands; cands = cands->next)
3253 if (cands->viable == 1)
3258 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3259 words, it is about to become the "this" pointer for a member
3260 function call. Take the address of the object. */
3263 build_this (tree obj)
3265 /* In a template, we are only concerned about the type of the
3266 expression, so we can take a shortcut. */
3267 if (processing_template_decl)
3268 return build_address (obj);
3270 return cp_build_addr_expr (obj, tf_warning_or_error);
3273 /* Returns true iff functions are equivalent. Equivalent functions are
3274 not '==' only if one is a function-local extern function or if
3275 both are extern "C". */
3278 equal_functions (tree fn1, tree fn2)
3280 if (TREE_CODE (fn1) != TREE_CODE (fn2))
3282 if (TREE_CODE (fn1) == TEMPLATE_DECL)
3284 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
3285 || DECL_EXTERN_C_FUNCTION_P (fn1))
3286 return decls_match (fn1, fn2);
3290 /* Print information about a candidate being rejected due to INFO. */
3293 print_conversion_rejection (location_t loc, struct conversion_info *info)
3295 tree from = info->from;
3297 from = lvalue_type (from);
3298 if (info->n_arg == -1)
3300 /* Conversion of implicit `this' argument failed. */
3301 if (!TYPE_P (info->from))
3302 /* A bad conversion for 'this' must be discarding cv-quals. */
3303 inform (loc, " passing %qT as %<this%> "
3304 "argument discards qualifiers",
3307 inform (loc, " no known conversion for implicit "
3308 "%<this%> parameter from %qT to %qT",
3309 from, info->to_type);
3311 else if (!TYPE_P (info->from))
3313 if (info->n_arg >= 0)
3314 inform (loc, " conversion of argument %d would be ill-formed:",
3316 perform_implicit_conversion (info->to_type, info->from,
3317 tf_warning_or_error);
3319 else if (info->n_arg == -2)
3320 /* Conversion of conversion function return value failed. */
3321 inform (loc, " no known conversion from %qT to %qT",
3322 from, info->to_type);
3324 inform (loc, " no known conversion for argument %d from %qT to %qT",
3325 info->n_arg + 1, from, info->to_type);
3328 /* Print information about a candidate with WANT parameters and we found
3332 print_arity_information (location_t loc, unsigned int have, unsigned int want)
3334 inform_n (loc, want,
3335 " candidate expects %d argument, %d provided",
3336 " candidate expects %d arguments, %d provided",
3340 /* Print information about one overload candidate CANDIDATE. MSGSTR
3341 is the text to print before the candidate itself.
3343 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3344 to have been run through gettext by the caller. This wart makes
3345 life simpler in print_z_candidates and for the translators. */
3348 print_z_candidate (location_t loc, const char *msgstr,
3349 struct z_candidate *candidate)
3351 const char *msg = (msgstr == NULL
3353 : ACONCAT ((msgstr, " ", NULL)));
3354 location_t cloc = location_of (candidate->fn);
3356 if (identifier_p (candidate->fn))
3359 if (candidate->num_convs == 3)
3360 inform (cloc, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn,
3361 candidate->convs[0]->type,
3362 candidate->convs[1]->type,
3363 candidate->convs[2]->type);
3364 else if (candidate->num_convs == 2)
3365 inform (cloc, "%s%D(%T, %T) <built-in>", msg, candidate->fn,
3366 candidate->convs[0]->type,
3367 candidate->convs[1]->type);
3369 inform (cloc, "%s%D(%T) <built-in>", msg, candidate->fn,
3370 candidate->convs[0]->type);
3372 else if (TYPE_P (candidate->fn))
3373 inform (cloc, "%s%T <conversion>", msg, candidate->fn);
3374 else if (candidate->viable == -1)
3375 inform (cloc, "%s%#D <near match>", msg, candidate->fn);
3376 else if (DECL_DELETED_FN (candidate->fn))
3377 inform (cloc, "%s%#D <deleted>", msg, candidate->fn);
3379 inform (cloc, "%s%#D", msg, candidate->fn);
3380 /* Give the user some information about why this candidate failed. */
3381 if (candidate->reason != NULL)
3383 struct rejection_reason *r = candidate->reason;
3388 print_arity_information (cloc, r->u.arity.actual,
3389 r->u.arity.expected);
3391 case rr_arg_conversion:
3392 print_conversion_rejection (cloc, &r->u.conversion);
3394 case rr_bad_arg_conversion:
3395 print_conversion_rejection (cloc, &r->u.bad_conversion);
3397 case rr_explicit_conversion:
3398 inform (cloc, " return type %qT of explicit conversion function "
3399 "cannot be converted to %qT with a qualification "
3400 "conversion", r->u.conversion.from,
3401 r->u.conversion.to_type);
3403 case rr_template_conversion:
3404 inform (cloc, " conversion from return type %qT of template "
3405 "conversion function specialization to %qT is not an "
3406 "exact match", r->u.conversion.from,
3407 r->u.conversion.to_type);
3409 case rr_template_unification:
3410 /* We use template_unification_error_rejection if unification caused
3411 actual non-SFINAE errors, in which case we don't need to repeat
3413 if (r->u.template_unification.tmpl == NULL_TREE)
3415 inform (cloc, " substitution of deduced template arguments "
3416 "resulted in errors seen above");
3419 /* Re-run template unification with diagnostics. */
3420 inform (cloc, " template argument deduction/substitution failed:");
3421 fn_type_unification (r->u.template_unification.tmpl,
3422 r->u.template_unification.explicit_targs,
3424 (r->u.template_unification.num_targs)),
3425 r->u.template_unification.args,
3426 r->u.template_unification.nargs,
3427 r->u.template_unification.return_type,
3428 r->u.template_unification.strict,
3429 r->u.template_unification.flags,
3432 case rr_invalid_copy:
3434 " a constructor taking a single argument of its own "
3435 "class type is invalid");
3439 /* This candidate didn't have any issues or we failed to
3440 handle a particular code. Either way... */
3447 print_z_candidates (location_t loc, struct z_candidate *candidates)
3449 struct z_candidate *cand1;
3450 struct z_candidate **cand2;
3456 /* Remove non-viable deleted candidates. */
3458 for (cand2 = &cand1; *cand2; )
3460 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3461 && !(*cand2)->viable
3462 && DECL_DELETED_FN ((*cand2)->fn))
3463 *cand2 = (*cand2)->next;
3465 cand2 = &(*cand2)->next;
3467 /* ...if there are any non-deleted ones. */
3471 /* There may be duplicates in the set of candidates. We put off
3472 checking this condition as long as possible, since we have no way
3473 to eliminate duplicates from a set of functions in less than n^2
3474 time. Now we are about to emit an error message, so it is more
3475 permissible to go slowly. */
3476 for (cand1 = candidates; cand1; cand1 = cand1->next)
3478 tree fn = cand1->fn;
3479 /* Skip builtin candidates and conversion functions. */
3482 cand2 = &cand1->next;
3485 if (DECL_P ((*cand2)->fn)
3486 && equal_functions (fn, (*cand2)->fn))
3487 *cand2 = (*cand2)->next;
3489 cand2 = &(*cand2)->next;
3493 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next)
3496 for (; candidates; candidates = candidates->next)
3497 print_z_candidate (loc, "candidate:", candidates);
3500 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3501 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3502 the result of the conversion function to convert it to the final
3503 desired type. Merge the two sequences into a single sequence,
3504 and return the merged sequence. */
3507 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3510 bool bad = user_seq->bad_p;
3512 gcc_assert (user_seq->kind == ck_user);
3514 /* Find the end of the second conversion sequence. */
3515 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next))
3517 /* The entire sequence is a user-conversion sequence. */
3518 (*t)->user_conv_p = true;
3523 /* Replace the identity conversion with the user conversion
3530 /* Handle overload resolution for initializing an object of class type from
3531 an initializer list. First we look for a suitable constructor that
3532 takes a std::initializer_list; if we don't find one, we then look for a
3533 non-list constructor.
3535 Parameters are as for add_candidates, except that the arguments are in
3536 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and
3537 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3540 add_list_candidates (tree fns, tree first_arg,
3541 tree init_list, tree totype,
3542 tree explicit_targs, bool template_only,
3543 tree conversion_path, tree access_path,
3545 struct z_candidate **candidates,
3546 tsubst_flags_t complain)
3548 vec<tree, va_gc> *args;
3550 gcc_assert (*candidates == NULL);
3552 /* We're looking for a ctor for list-initialization. */
3553 flags |= LOOKUP_LIST_INIT_CTOR;
3554 /* And we don't allow narrowing conversions. We also use this flag to
3555 avoid the copy constructor call for copy-list-initialization. */
3556 flags |= LOOKUP_NO_NARROWING;
3558 /* Always use the default constructor if the list is empty (DR 990). */
3559 if (CONSTRUCTOR_NELTS (init_list) == 0
3560 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3562 /* If the class has a list ctor, try passing the list as a single
3563 argument first, but only consider list ctors. */
3564 else if (TYPE_HAS_LIST_CTOR (totype))
3566 flags |= LOOKUP_LIST_ONLY;
3567 args = make_tree_vector_single (init_list);
3568 add_candidates (fns, first_arg, args, NULL_TREE,
3569 explicit_targs, template_only, conversion_path,
3570 access_path, flags, candidates, complain);
3571 if (any_strictly_viable (*candidates))
3575 args = ctor_to_vec (init_list);
3577 /* We aren't looking for list-ctors anymore. */
3578 flags &= ~LOOKUP_LIST_ONLY;
3579 /* We allow more user-defined conversions within an init-list. */
3580 flags &= ~LOOKUP_NO_CONVERSION;
3582 add_candidates (fns, first_arg, args, NULL_TREE,
3583 explicit_targs, template_only, conversion_path,
3584 access_path, flags, candidates, complain);
3587 /* Returns the best overload candidate to perform the requested
3588 conversion. This function is used for three the overloading situations
3589 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3590 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as
3591 per [dcl.init.ref], so we ignore temporary bindings. */
3593 static struct z_candidate *
3594 build_user_type_conversion_1 (tree totype, tree expr, int flags,
3595 tsubst_flags_t complain)
3597 struct z_candidate *candidates, *cand;
3599 tree ctors = NULL_TREE;
3600 tree conv_fns = NULL_TREE;
3601 conversion *conv = NULL;
3602 tree first_arg = NULL_TREE;
3603 vec<tree, va_gc> *args = NULL;
3610 fromtype = TREE_TYPE (expr);
3612 /* We represent conversion within a hierarchy using RVALUE_CONV and
3613 BASE_CONV, as specified by [over.best.ics]; these become plain
3614 constructor calls, as specified in [dcl.init]. */
3615 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3616 || !DERIVED_FROM_P (totype, fromtype));
3618 if (MAYBE_CLASS_TYPE_P (totype))
3619 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3620 creating a garbage BASELINK; constructors can't be inherited. */
3621 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier);
3623 if (MAYBE_CLASS_TYPE_P (fromtype))
3625 tree to_nonref = non_reference (totype);
3626 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3627 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3628 && DERIVED_FROM_P (to_nonref, fromtype)))
3630 /* [class.conv.fct] A conversion function is never used to
3631 convert a (possibly cv-qualified) object to the (possibly
3632 cv-qualified) same object type (or a reference to it), to a
3633 (possibly cv-qualified) base class of that type (or a
3634 reference to it)... */
3637 conv_fns = lookup_conversions (fromtype);
3641 flags |= LOOKUP_NO_CONVERSION;
3642 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3643 flags |= LOOKUP_NO_NARROWING;
3645 /* It's OK to bind a temporary for converting constructor arguments, but
3646 not in converting the return value of a conversion operator. */
3647 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION
3648 | (flags & LOOKUP_NO_NARROWING));
3649 flags &= ~LOOKUP_NO_TEMP_BIND;
3653 int ctorflags = flags;
3655 first_arg = build_dummy_object (totype);
3657 /* We should never try to call the abstract or base constructor
3659 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
3660 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
3662 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3664 /* List-initialization. */
3665 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE,
3666 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3667 ctorflags, &candidates, complain);
3671 args = make_tree_vector_single (expr);
3672 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3673 TYPE_BINFO (totype), TYPE_BINFO (totype),
3674 ctorflags, &candidates, complain);
3677 for (cand = candidates; cand; cand = cand->next)
3679 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3681 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3682 set, then this is copy-initialization. In that case, "The
3683 result of the call is then used to direct-initialize the
3684 object that is the destination of the copy-initialization."
3687 We represent this in the conversion sequence with an
3688 rvalue conversion, which means a constructor call. */
3689 if (TREE_CODE (totype) != REFERENCE_TYPE
3690 && !(convflags & LOOKUP_NO_TEMP_BIND))
3692 = build_conv (ck_rvalue, totype, cand->second_conv);
3699 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3701 tree conversion_path = TREE_PURPOSE (conv_fns);
3702 struct z_candidate *old_candidates;
3704 /* If we are called to convert to a reference type, we are trying to
3705 find a direct binding, so don't even consider temporaries. If
3706 we don't find a direct binding, the caller will try again to
3707 look for a temporary binding. */
3708 if (TREE_CODE (totype) == REFERENCE_TYPE)
3709 convflags |= LOOKUP_NO_TEMP_BIND;
3711 old_candidates = candidates;
3712 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3714 conversion_path, TYPE_BINFO (fromtype),
3715 flags, &candidates, complain);
3717 for (cand = candidates; cand != old_candidates; cand = cand->next)
3719 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3721 = implicit_conversion (totype,
3724 /*c_cast_p=*/false, convflags,
3727 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3728 copy-initialization. In that case, "The result of the
3729 call is then used to direct-initialize the object that is
3730 the destination of the copy-initialization." [dcl.init]
3732 We represent this in the conversion sequence with an
3733 rvalue conversion, which means a constructor call. But
3734 don't add a second rvalue conversion if there's already
3735 one there. Which there really shouldn't be, but it's
3736 harmless since we'd add it here anyway. */
3737 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3738 && !(convflags & LOOKUP_NO_TEMP_BIND))
3739 ics = build_conv (ck_rvalue, totype, ics);
3741 cand->second_conv = ics;
3746 cand->reason = arg_conversion_rejection (NULL_TREE, -2,
3749 else if (DECL_NONCONVERTING_P (cand->fn)
3750 && ics->rank > cr_exact)
3752 /* 13.3.1.5: For direct-initialization, those explicit
3753 conversion functions that are not hidden within S and
3754 yield type T or a type that can be converted to type T
3755 with a qualification conversion (4.4) are also candidate
3757 /* 13.3.1.6 doesn't have a parallel restriction, but it should;
3758 I've raised this issue with the committee. --jason 9/2011 */
3760 cand->reason = explicit_conversion_rejection (rettype, totype);
3762 else if (cand->viable == 1 && ics->bad_p)
3766 = bad_arg_conversion_rejection (NULL_TREE, -2,
3769 else if (primary_template_instantiation_p (cand->fn)
3770 && ics->rank > cr_exact)
3772 /* 13.3.3.1.2: If the user-defined conversion is specified by
3773 a specialization of a conversion function template, the
3774 second standard conversion sequence shall have exact match
3777 cand->reason = template_conversion_rejection (rettype, totype);
3782 candidates = splice_viable (candidates, false, &any_viable_p);
3786 release_tree_vector (args);
3790 cand = tourney (candidates, complain);
3793 if (complain & tf_error)
3795 error ("conversion from %qT to %qT is ambiguous",
3797 print_z_candidates (location_of (expr), candidates);
3800 cand = candidates; /* any one will do */
3801 cand->second_conv = build_ambiguous_conv (totype, expr);
3802 cand->second_conv->user_conv_p = true;
3803 if (!any_strictly_viable (candidates))
3804 cand->second_conv->bad_p = true;
3805 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3806 ambiguous conversion is no worse than another user-defined
3813 if (!DECL_CONSTRUCTOR_P (cand->fn))
3814 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn)));
3815 else if (cand->second_conv->kind == ck_rvalue)
3816 /* DR 5: [in the first step of copy-initialization]...if the function
3817 is a constructor, the call initializes a temporary of the
3818 cv-unqualified version of the destination type. */
3819 convtype = cv_unqualified (totype);
3822 /* Build the user conversion sequence. */
3826 build_identity_conv (TREE_TYPE (expr), expr));
3828 if (cand->viable == -1)
3831 /* Remember that this was a list-initialization. */
3832 if (flags & LOOKUP_NO_NARROWING)
3833 conv->check_narrowing = true;
3835 /* Combine it with the second conversion sequence. */
3836 cand->second_conv = merge_conversion_sequences (conv,
3842 /* Wrapper for above. */
3845 build_user_type_conversion (tree totype, tree expr, int flags,
3846 tsubst_flags_t complain)
3848 struct z_candidate *cand;
3851 bool subtime = timevar_cond_start (TV_OVERLOAD);
3852 cand = build_user_type_conversion_1 (totype, expr, flags, complain);
3856 if (cand->second_conv->kind == ck_ambig)
3857 ret = error_mark_node;
3860 expr = convert_like (cand->second_conv, expr, complain);
3861 ret = convert_from_reference (expr);
3867 timevar_cond_stop (TV_OVERLOAD, subtime);
3871 /* Subroutine of convert_nontype_argument.
3873 EXPR is an argument for a template non-type parameter of integral or
3874 enumeration type. Do any necessary conversions (that are permitted for
3875 non-type arguments) to convert it to the parameter type.
3877 If conversion is successful, returns the converted expression;
3878 otherwise, returns error_mark_node. */
3881 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain)
3886 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
3888 if (error_operand_p (expr))
3889 return error_mark_node;
3891 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3893 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3894 p = conversion_obstack_alloc (0);
3896 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
3898 LOOKUP_IMPLICIT, complain);
3900 /* for a non-type template-parameter of integral or
3901 enumeration type, integral promotions (4.5) and integral
3902 conversions (4.7) are applied. */
3903 /* It should be sufficient to check the outermost conversion step, since
3904 there are no qualification conversions to integer type. */
3908 /* A conversion function is OK. If it isn't constexpr, we'll
3909 complain later that the argument isn't constant. */
3911 /* The lvalue-to-rvalue conversion is OK. */
3917 t = next_conversion (conv)->type;
3918 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t))
3921 if (complain & tf_error)
3922 error_at (loc, "conversion from %qT to %qT not considered for "
3923 "non-type template argument", t, type);
3924 /* and fall through. */
3932 expr = convert_like (conv, expr, complain);
3934 expr = error_mark_node;
3936 /* Free all the conversions we allocated. */
3937 obstack_free (&conversion_obstack, p);
3942 /* Do any initial processing on the arguments to a function call. */
3944 static vec<tree, va_gc> *
3945 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain)
3950 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
3952 if (error_operand_p (arg))
3954 else if (VOID_TYPE_P (TREE_TYPE (arg)))
3956 if (complain & tf_error)
3957 error ("invalid use of void expression");
3960 else if (invalid_nonstatic_memfn_p (arg, complain))
3966 /* Perform overload resolution on FN, which is called with the ARGS.
3968 Return the candidate function selected by overload resolution, or
3969 NULL if the event that overload resolution failed. In the case
3970 that overload resolution fails, *CANDIDATES will be the set of
3971 candidates considered, and ANY_VIABLE_P will be set to true or
3972 false to indicate whether or not any of the candidates were
3975 The ARGS should already have gone through RESOLVE_ARGS before this
3976 function is called. */
3978 static struct z_candidate *
3979 perform_overload_resolution (tree fn,
3980 const vec<tree, va_gc> *args,
3981 struct z_candidate **candidates,
3982 bool *any_viable_p, tsubst_flags_t complain)
3984 struct z_candidate *cand;
3985 tree explicit_targs;
3988 bool subtime = timevar_cond_start (TV_OVERLOAD);
3990 explicit_targs = NULL_TREE;
3994 *any_viable_p = true;
3997 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
3998 || TREE_CODE (fn) == TEMPLATE_DECL
3999 || TREE_CODE (fn) == OVERLOAD
4000 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
4002 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4004 explicit_targs = TREE_OPERAND (fn, 1);
4005 fn = TREE_OPERAND (fn, 0);
4009 /* Add the various candidate functions. */
4010 add_candidates (fn, NULL_TREE, args, NULL_TREE,
4011 explicit_targs, template_only,
4012 /*conversion_path=*/NULL_TREE,
4013 /*access_path=*/NULL_TREE,
4015 candidates, complain);
4017 *candidates = splice_viable (*candidates, false, any_viable_p);
4019 cand = tourney (*candidates, complain);
4023 timevar_cond_stop (TV_OVERLOAD, subtime);
4027 /* Print an error message about being unable to build a call to FN with
4028 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
4029 be located; CANDIDATES is a possibly empty list of such
4033 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args,
4034 struct z_candidate *candidates)
4036 tree name = DECL_NAME (OVL_CURRENT (fn));
4037 location_t loc = location_of (name);
4039 if (!any_strictly_viable (candidates))
4040 error_at (loc, "no matching function for call to %<%D(%A)%>",
4041 name, build_tree_list_vec (args));
4043 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
4044 name, build_tree_list_vec (args));
4046 print_z_candidates (loc, candidates);
4049 /* Return an expression for a call to FN (a namespace-scope function,
4050 or a static member function) with the ARGS. This may change
4054 build_new_function_call (tree fn, vec<tree, va_gc> **args, bool koenig_p,
4055 tsubst_flags_t complain)
4057 struct z_candidate *candidates, *cand;
4062 if (args != NULL && *args != NULL)
4064 *args = resolve_args (*args, complain);
4066 return error_mark_node;
4070 tm_malloc_replacement (fn);
4072 /* If this function was found without using argument dependent
4073 lookup, then we want to ignore any undeclared friend
4079 fn = remove_hidden_names (fn);
4082 if (complain & tf_error)
4083 print_error_for_call_failure (orig_fn, *args, NULL);
4084 return error_mark_node;
4088 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4089 p = conversion_obstack_alloc (0);
4091 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p,
4096 if (complain & tf_error)
4098 if (!any_viable_p && candidates && ! candidates->next
4099 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
4100 return cp_build_function_call_vec (candidates->fn, args, complain);
4101 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4102 fn = TREE_OPERAND (fn, 0);
4103 print_error_for_call_failure (fn, *args, candidates);
4105 result = error_mark_node;
4109 int flags = LOOKUP_NORMAL;
4110 /* If fn is template_id_expr, the call has explicit template arguments
4111 (e.g. func<int>(5)), communicate this info to build_over_call
4112 through flags so that later we can use it to decide whether to warn
4113 about peculiar null pointer conversion. */
4114 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4115 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
4116 result = build_over_call (cand, flags, complain);
4119 /* Free all the conversions we allocated. */
4120 obstack_free (&conversion_obstack, p);
4125 /* Build a call to a global operator new. FNNAME is the name of the
4126 operator (either "operator new" or "operator new[]") and ARGS are
4127 the arguments provided. This may change ARGS. *SIZE points to the
4128 total number of bytes required by the allocation, and is updated if
4129 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
4130 be used. If this function determines that no cookie should be
4131 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK
4132 is not NULL_TREE, it is evaluated before calculating the final
4133 array size, and if it fails, the array size is replaced with
4134 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN
4135 is non-NULL, it will be set, upon return, to the allocation
4139 build_operator_new_call (tree fnname, vec<tree, va_gc> **args,
4140 tree *size, tree *cookie_size, tree size_check,
4141 tree *fn, tsubst_flags_t complain)
4143 tree original_size = *size;
4145 struct z_candidate *candidates;
4146 struct z_candidate *cand;
4151 /* Set to (size_t)-1 if the size check fails. */
4152 if (size_check != NULL_TREE)
4154 tree errval = TYPE_MAX_VALUE (sizetype);
4155 if (cxx_dialect >= cxx11 && flag_exceptions)
4156 errval = throw_bad_array_new_length ();
4157 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4158 original_size, errval);
4160 vec_safe_insert (*args, 0, *size);
4161 *args = resolve_args (*args, complain);
4163 return error_mark_node;
4169 If this lookup fails to find the name, or if the allocated type
4170 is not a class type, the allocation function's name is looked
4171 up in the global scope.
4173 we disregard block-scope declarations of "operator new". */
4174 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
4176 /* Figure out what function is being called. */
4177 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p,
4180 /* If no suitable function could be found, issue an error message
4184 if (complain & tf_error)
4185 print_error_for_call_failure (fns, *args, candidates);
4186 return error_mark_node;
4189 /* If a cookie is required, add some extra space. Whether
4190 or not a cookie is required cannot be determined until
4191 after we know which function was called. */
4194 bool use_cookie = true;
4197 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
4198 /* Skip the size_t parameter. */
4199 arg_types = TREE_CHAIN (arg_types);
4200 /* Check the remaining parameters (if any). */
4202 && TREE_CHAIN (arg_types) == void_list_node
4203 && same_type_p (TREE_VALUE (arg_types),
4206 /* If we need a cookie, adjust the number of bytes allocated. */
4209 /* Update the total size. */
4210 *size = size_binop (PLUS_EXPR, original_size, *cookie_size);
4211 /* Set to (size_t)-1 if the size check fails. */
4212 gcc_assert (size_check != NULL_TREE);
4213 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4214 *size, TYPE_MAX_VALUE (sizetype));
4215 /* Update the argument list to reflect the adjusted size. */
4216 (**args)[0] = *size;
4219 *cookie_size = NULL_TREE;
4222 /* Tell our caller which function we decided to call. */
4226 /* Build the CALL_EXPR. */
4227 return build_over_call (cand, LOOKUP_NORMAL, complain);
4230 /* Build a new call to operator(). This may change ARGS. */
4233 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4235 struct z_candidate *candidates = 0, *cand;
4236 tree fns, convs, first_mem_arg = NULL_TREE;
4237 tree type = TREE_TYPE (obj);
4239 tree result = NULL_TREE;
4242 if (error_operand_p (obj))
4243 return error_mark_node;
4245 obj = prep_operand (obj);
4247 if (TYPE_PTRMEMFUNC_P (type))
4249 if (complain & tf_error)
4250 /* It's no good looking for an overloaded operator() on a
4251 pointer-to-member-function. */
4252 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
4253 return error_mark_node;
4256 if (TYPE_BINFO (type))
4258 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
4259 if (fns == error_mark_node)
4260 return error_mark_node;
4265 if (args != NULL && *args != NULL)
4267 *args = resolve_args (*args, complain);
4269 return error_mark_node;
4272 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4273 p = conversion_obstack_alloc (0);
4277 first_mem_arg = obj;
4279 add_candidates (BASELINK_FUNCTIONS (fns),
4280 first_mem_arg, *args, NULL_TREE,
4282 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
4283 LOOKUP_NORMAL, &candidates, complain);
4286 convs = lookup_conversions (type);
4288 for (; convs; convs = TREE_CHAIN (convs))
4290 tree fns = TREE_VALUE (convs);
4291 tree totype = TREE_TYPE (convs);
4293 if (TYPE_PTRFN_P (totype)
4294 || TYPE_REFFN_P (totype)
4295 || (TREE_CODE (totype) == REFERENCE_TYPE
4296 && TYPE_PTRFN_P (TREE_TYPE (totype))))
4297 for (; fns; fns = OVL_NEXT (fns))
4299 tree fn = OVL_CURRENT (fns);
4301 if (DECL_NONCONVERTING_P (fn))
4304 if (TREE_CODE (fn) == TEMPLATE_DECL)
4305 add_template_conv_candidate
4306 (&candidates, fn, obj, NULL_TREE, *args, totype,
4307 /*access_path=*/NULL_TREE,
4308 /*conversion_path=*/NULL_TREE, complain);
4310 add_conv_candidate (&candidates, fn, obj, NULL_TREE,
4311 *args, /*conversion_path=*/NULL_TREE,
4312 /*access_path=*/NULL_TREE, complain);
4316 /* Be strict here because if we choose a bad conversion candidate, the
4317 errors we get won't mention the call context. */
4318 candidates = splice_viable (candidates, true, &any_viable_p);
4321 if (complain & tf_error)
4323 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
4324 build_tree_list_vec (*args));
4325 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4327 result = error_mark_node;
4331 cand = tourney (candidates, complain);
4334 if (complain & tf_error)
4336 error ("call of %<(%T) (%A)%> is ambiguous",
4337 TREE_TYPE (obj), build_tree_list_vec (*args));
4338 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4340 result = error_mark_node;
4342 /* Since cand->fn will be a type, not a function, for a conversion
4343 function, we must be careful not to unconditionally look at
4345 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
4346 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
4347 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4350 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
4352 obj = convert_from_reference (obj);
4353 result = cp_build_function_call_vec (obj, args, complain);
4357 /* Free all the conversions we allocated. */
4358 obstack_free (&conversion_obstack, p);
4363 /* Wrapper for above. */
4366 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4369 bool subtime = timevar_cond_start (TV_OVERLOAD);
4370 ret = build_op_call_1 (obj, args, complain);
4371 timevar_cond_stop (TV_OVERLOAD, subtime);
4375 /* Called by op_error to prepare format strings suitable for the error
4376 function. It concatenates a prefix (controlled by MATCH), ERRMSG,
4377 and a suffix (controlled by NTYPES). */
4380 op_error_string (const char *errmsg, int ntypes, bool match)
4384 const char *msgp = concat (match ? G_("ambiguous overload for ")
4385 : G_("no match for "), errmsg, NULL);
4388 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL);
4389 else if (ntypes == 2)
4390 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL);
4392 msg = concat (msgp, G_(" (operand type is %qT)"), NULL);
4398 op_error (location_t loc, enum tree_code code, enum tree_code code2,
4399 tree arg1, tree arg2, tree arg3, bool match)
4403 if (code == MODIFY_EXPR)
4404 opname = assignment_operator_name_info[code2].name;
4406 opname = operator_name_info[code].name;
4411 if (flag_diagnostics_show_caret)
4412 error_at (loc, op_error_string (G_("ternary %<operator?:%>"),
4414 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4416 error_at (loc, op_error_string (G_("ternary %<operator?:%> "
4417 "in %<%E ? %E : %E%>"), 3, match),
4419 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4422 case POSTINCREMENT_EXPR:
4423 case POSTDECREMENT_EXPR:
4424 if (flag_diagnostics_show_caret)
4425 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4426 opname, TREE_TYPE (arg1));
4428 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"),
4430 opname, arg1, opname, TREE_TYPE (arg1));
4434 if (flag_diagnostics_show_caret)
4435 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match),
4436 TREE_TYPE (arg1), TREE_TYPE (arg2));
4438 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"),
4440 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2));
4445 if (flag_diagnostics_show_caret)
4446 error_at (loc, op_error_string (G_("%qs"), 1, match),
4447 opname, TREE_TYPE (arg1));
4449 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match),
4450 opname, opname, arg1, TREE_TYPE (arg1));
4455 if (flag_diagnostics_show_caret)
4456 error_at (loc, op_error_string (G_("%<operator%s%>"), 2, match),
4457 opname, TREE_TYPE (arg1), TREE_TYPE (arg2));
4459 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"),
4461 opname, arg1, opname, arg2,
4462 TREE_TYPE (arg1), TREE_TYPE (arg2));
4464 if (flag_diagnostics_show_caret)
4465 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4466 opname, TREE_TYPE (arg1));
4468 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"),
4470 opname, opname, arg1, TREE_TYPE (arg1));
4475 /* Return the implicit conversion sequence that could be used to
4476 convert E1 to E2 in [expr.cond]. */
4479 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain)
4481 tree t1 = non_reference (TREE_TYPE (e1));
4482 tree t2 = non_reference (TREE_TYPE (e2));
4488 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4489 implicitly converted (clause _conv_) to the type "lvalue reference to
4490 T2", subject to the constraint that in the conversion the
4491 reference must bind directly (_dcl.init.ref_) to an lvalue.
4493 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
4494 implicitly converted to the type "rvalue reference to T2", subject to
4495 the constraint that the reference must bind directly. */
4496 if (lvalue_or_rvalue_with_address_p (e2))
4498 tree rtype = cp_build_reference_type (t2, !real_lvalue_p (e2));
4499 conv = implicit_conversion (rtype,
4503 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND
4504 |LOOKUP_ONLYCONVERTING,
4506 if (conv && !conv->bad_p)
4510 /* If E2 is a prvalue or if neither of the conversions above can be done
4511 and at least one of the operands has (possibly cv-qualified) class
4513 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2))
4518 If E1 and E2 have class type, and the underlying class types are
4519 the same or one is a base class of the other: E1 can be converted
4520 to match E2 if the class of T2 is the same type as, or a base
4521 class of, the class of T1, and the cv-qualification of T2 is the
4522 same cv-qualification as, or a greater cv-qualification than, the
4523 cv-qualification of T1. If the conversion is applied, E1 is
4524 changed to an rvalue of type T2 that still refers to the original
4525 source class object (or the appropriate subobject thereof). */
4526 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4527 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4529 if (good_base && at_least_as_qualified_p (t2, t1))
4531 conv = build_identity_conv (t1, e1);
4532 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4533 TYPE_MAIN_VARIANT (t2)))
4534 conv = build_conv (ck_base, t2, conv);
4536 conv = build_conv (ck_rvalue, t2, conv);
4545 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4546 converted to the type that expression E2 would have if E2 were
4547 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4548 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4549 LOOKUP_IMPLICIT, complain);
4552 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4553 arguments to the conditional expression. */
4556 build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3,
4557 tsubst_flags_t complain)
4561 tree result = NULL_TREE;
4562 tree result_type = NULL_TREE;
4563 bool lvalue_p = true;
4564 struct z_candidate *candidates = 0;
4565 struct z_candidate *cand;
4567 tree orig_arg2, orig_arg3;
4569 /* As a G++ extension, the second argument to the conditional can be
4570 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4571 c'.) If the second operand is omitted, make sure it is
4572 calculated only once. */
4575 if (complain & tf_error)
4576 pedwarn (loc, OPT_Wpedantic,
4577 "ISO C++ forbids omitting the middle term of a ?: expression");
4579 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4580 if (real_lvalue_p (arg1))
4581 arg2 = arg1 = stabilize_reference (arg1);
4583 arg2 = arg1 = save_expr (arg1);
4586 /* If something has already gone wrong, just pass that fact up the
4588 if (error_operand_p (arg1)
4589 || error_operand_p (arg2)
4590 || error_operand_p (arg3))
4591 return error_mark_node;
4596 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1)))
4598 arg1 = force_rvalue (arg1, complain);
4599 arg2 = force_rvalue (arg2, complain);
4600 arg3 = force_rvalue (arg3, complain);
4602 /* force_rvalue can return error_mark on valid arguments. */
4603 if (error_operand_p (arg1)
4604 || error_operand_p (arg2)
4605 || error_operand_p (arg3))
4606 return error_mark_node;
4608 tree arg1_type = TREE_TYPE (arg1);
4609 arg2_type = TREE_TYPE (arg2);
4610 arg3_type = TREE_TYPE (arg3);
4612 if (TREE_CODE (arg2_type) != VECTOR_TYPE
4613 && TREE_CODE (arg3_type) != VECTOR_TYPE)
4615 /* Rely on the error messages of the scalar version. */
4616 tree scal = build_conditional_expr_1 (loc, integer_one_node,
4617 orig_arg2, orig_arg3, complain);
4618 if (scal == error_mark_node)
4619 return error_mark_node;
4620 tree stype = TREE_TYPE (scal);
4621 tree ctype = TREE_TYPE (arg1_type);
4622 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype)
4623 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype)))
4625 if (complain & tf_error)
4626 error_at (loc, "inferred scalar type %qT is not an integer or "
4627 "floating point type of the same size as %qT", stype,
4628 COMPARISON_CLASS_P (arg1)
4629 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0)))
4631 return error_mark_node;
4634 tree vtype = build_opaque_vector_type (stype,
4635 TYPE_VECTOR_SUBPARTS (arg1_type));
4636 /* We could pass complain & tf_warning to unsafe_conversion_p,
4637 but the warnings (like Wsign-conversion) have already been
4638 given by the scalar build_conditional_expr_1. We still check
4639 unsafe_conversion_p to forbid truncating long long -> float. */
4640 if (unsafe_conversion_p (loc, stype, arg2, false))
4642 if (complain & tf_error)
4643 error_at (loc, "conversion of scalar %qT to vector %qT "
4644 "involves truncation", arg2_type, vtype);
4645 return error_mark_node;
4647 if (unsafe_conversion_p (loc, stype, arg3, false))
4649 if (complain & tf_error)
4650 error_at (loc, "conversion of scalar %qT to vector %qT "
4651 "involves truncation", arg3_type, vtype);
4652 return error_mark_node;
4655 arg2 = cp_convert (stype, arg2, complain);
4656 arg2 = save_expr (arg2);
4657 arg2 = build_vector_from_val (vtype, arg2);
4659 arg3 = cp_convert (stype, arg3, complain);
4660 arg3 = save_expr (arg3);
4661 arg3 = build_vector_from_val (vtype, arg3);
4665 if ((TREE_CODE (arg2_type) == VECTOR_TYPE)
4666 != (TREE_CODE (arg3_type) == VECTOR_TYPE))
4668 enum stv_conv convert_flag =
4669 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3,
4670 complain & tf_error);
4672 switch (convert_flag)
4675 return error_mark_node;
4678 arg2 = save_expr (arg2);
4679 arg2 = convert (TREE_TYPE (arg3_type), arg2);
4680 arg2 = build_vector_from_val (arg3_type, arg2);
4681 arg2_type = TREE_TYPE (arg2);
4686 arg3 = save_expr (arg3);
4687 arg3 = convert (TREE_TYPE (arg2_type), arg3);
4688 arg3 = build_vector_from_val (arg2_type, arg3);
4689 arg3_type = TREE_TYPE (arg3);
4697 if (!same_type_p (arg2_type, arg3_type)
4698 || TYPE_VECTOR_SUBPARTS (arg1_type)
4699 != TYPE_VECTOR_SUBPARTS (arg2_type)
4700 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type))
4702 if (complain & tf_error)
4704 "incompatible vector types in conditional expression: "
4705 "%qT, %qT and %qT", TREE_TYPE (arg1),
4706 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3));
4707 return error_mark_node;
4710 if (!COMPARISON_CLASS_P (arg1))
4711 arg1 = cp_build_binary_op (loc, NE_EXPR, arg1,
4712 build_zero_cst (arg1_type), complain);
4713 return fold_build3 (VEC_COND_EXPR, arg2_type, arg1, arg2, arg3);
4718 The first expression is implicitly converted to bool (clause
4720 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4722 if (error_operand_p (arg1))
4723 return error_mark_node;
4727 If either the second or the third operand has type (possibly
4728 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4729 array-to-pointer (_conv.array_), and function-to-pointer
4730 (_conv.func_) standard conversions are performed on the second
4731 and third operands. */
4732 arg2_type = unlowered_expr_type (arg2);
4733 arg3_type = unlowered_expr_type (arg3);
4734 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4736 /* Do the conversions. We don't these for `void' type arguments
4737 since it can't have any effect and since decay_conversion
4738 does not handle that case gracefully. */
4739 if (!VOID_TYPE_P (arg2_type))
4740 arg2 = decay_conversion (arg2, complain);
4741 if (!VOID_TYPE_P (arg3_type))
4742 arg3 = decay_conversion (arg3, complain);
4743 arg2_type = TREE_TYPE (arg2);
4744 arg3_type = TREE_TYPE (arg3);
4748 One of the following shall hold:
4750 --The second or the third operand (but not both) is a
4751 throw-expression (_except.throw_); the result is of the
4752 type of the other and is an rvalue.
4754 --Both the second and the third operands have type void; the
4755 result is of type void and is an rvalue.
4757 We must avoid calling force_rvalue for expressions of type
4758 "void" because it will complain that their value is being
4760 if (TREE_CODE (arg2) == THROW_EXPR
4761 && TREE_CODE (arg3) != THROW_EXPR)
4763 if (!VOID_TYPE_P (arg3_type))
4765 arg3 = force_rvalue (arg3, complain);
4766 if (arg3 == error_mark_node)
4767 return error_mark_node;
4769 arg3_type = TREE_TYPE (arg3);
4770 result_type = arg3_type;
4772 else if (TREE_CODE (arg2) != THROW_EXPR
4773 && TREE_CODE (arg3) == THROW_EXPR)
4775 if (!VOID_TYPE_P (arg2_type))
4777 arg2 = force_rvalue (arg2, complain);
4778 if (arg2 == error_mark_node)
4779 return error_mark_node;
4781 arg2_type = TREE_TYPE (arg2);
4782 result_type = arg2_type;
4784 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
4785 result_type = void_type_node;
4788 if (complain & tf_error)
4790 if (VOID_TYPE_P (arg2_type))
4791 error_at (EXPR_LOC_OR_LOC (arg3, loc),
4792 "second operand to the conditional operator "
4793 "is of type %<void%>, but the third operand is "
4794 "neither a throw-expression nor of type %<void%>");
4796 error_at (EXPR_LOC_OR_LOC (arg2, loc),
4797 "third operand to the conditional operator "
4798 "is of type %<void%>, but the second operand is "
4799 "neither a throw-expression nor of type %<void%>");
4801 return error_mark_node;
4805 goto valid_operands;
4809 Otherwise, if the second and third operand have different types,
4810 and either has (possibly cv-qualified) class type, or if both are
4811 glvalues of the same value category and the same type except for
4812 cv-qualification, an attempt is made to convert each of those operands
4813 to the type of the other. */
4814 else if (!same_type_p (arg2_type, arg3_type)
4815 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)
4816 || (same_type_ignoring_top_level_qualifiers_p (arg2_type,
4818 && lvalue_or_rvalue_with_address_p (arg2)
4819 && lvalue_or_rvalue_with_address_p (arg3)
4820 && real_lvalue_p (arg2) == real_lvalue_p (arg3))))
4824 bool converted = false;
4826 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4827 p = conversion_obstack_alloc (0);
4829 conv2 = conditional_conversion (arg2, arg3, complain);
4830 conv3 = conditional_conversion (arg3, arg2, complain);
4834 If both can be converted, or one can be converted but the
4835 conversion is ambiguous, the program is ill-formed. If
4836 neither can be converted, the operands are left unchanged and
4837 further checking is performed as described below. If exactly
4838 one conversion is possible, that conversion is applied to the
4839 chosen operand and the converted operand is used in place of
4840 the original operand for the remainder of this section. */
4841 if ((conv2 && !conv2->bad_p
4842 && conv3 && !conv3->bad_p)
4843 || (conv2 && conv2->kind == ck_ambig)
4844 || (conv3 && conv3->kind == ck_ambig))
4846 if (complain & tf_error)
4848 error_at (loc, "operands to ?: have different types %qT and %qT",
4849 arg2_type, arg3_type);
4850 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p)
4851 inform (loc, " and each type can be converted to the other");
4852 else if (conv2 && conv2->kind == ck_ambig)
4853 convert_like (conv2, arg2, complain);
4855 convert_like (conv3, arg3, complain);
4857 result = error_mark_node;
4859 else if (conv2 && !conv2->bad_p)
4861 arg2 = convert_like (conv2, arg2, complain);
4862 arg2 = convert_from_reference (arg2);
4863 arg2_type = TREE_TYPE (arg2);
4864 /* Even if CONV2 is a valid conversion, the result of the
4865 conversion may be invalid. For example, if ARG3 has type
4866 "volatile X", and X does not have a copy constructor
4867 accepting a "volatile X&", then even if ARG2 can be
4868 converted to X, the conversion will fail. */
4869 if (error_operand_p (arg2))
4870 result = error_mark_node;
4873 else if (conv3 && !conv3->bad_p)
4875 arg3 = convert_like (conv3, arg3, complain);
4876 arg3 = convert_from_reference (arg3);
4877 arg3_type = TREE_TYPE (arg3);
4878 if (error_operand_p (arg3))
4879 result = error_mark_node;
4883 /* Free all the conversions we allocated. */
4884 obstack_free (&conversion_obstack, p);
4889 /* If, after the conversion, both operands have class type,
4890 treat the cv-qualification of both operands as if it were the
4891 union of the cv-qualification of the operands.
4893 The standard is not clear about what to do in this
4894 circumstance. For example, if the first operand has type
4895 "const X" and the second operand has a user-defined
4896 conversion to "volatile X", what is the type of the second
4897 operand after this step? Making it be "const X" (matching
4898 the first operand) seems wrong, as that discards the
4899 qualification without actually performing a copy. Leaving it
4900 as "volatile X" seems wrong as that will result in the
4901 conditional expression failing altogether, even though,
4902 according to this step, the one operand could be converted to
4903 the type of the other. */
4905 && CLASS_TYPE_P (arg2_type)
4906 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
4907 arg2_type = arg3_type =
4908 cp_build_qualified_type (arg2_type,
4909 cp_type_quals (arg2_type)
4910 | cp_type_quals (arg3_type));
4915 If the second and third operands are glvalues of the same value
4916 category and have the same type, the result is of that type and
4918 if (((real_lvalue_p (arg2) && real_lvalue_p (arg3))
4919 || (xvalue_p (arg2) && xvalue_p (arg3)))
4920 && same_type_p (arg2_type, arg3_type))
4922 result_type = arg2_type;
4923 arg2 = mark_lvalue_use (arg2);
4924 arg3 = mark_lvalue_use (arg3);
4925 goto valid_operands;
4930 Otherwise, the result is an rvalue. If the second and third
4931 operand do not have the same type, and either has (possibly
4932 cv-qualified) class type, overload resolution is used to
4933 determine the conversions (if any) to be applied to the operands
4934 (_over.match.oper_, _over.built_). */
4936 if (!same_type_p (arg2_type, arg3_type)
4937 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4943 /* Rearrange the arguments so that add_builtin_candidate only has
4944 to know about two args. In build_builtin_candidate, the
4945 arguments are unscrambled. */
4949 add_builtin_candidates (&candidates,
4952 ansi_opname (COND_EXPR),
4954 LOOKUP_NORMAL, complain);
4958 If the overload resolution fails, the program is
4960 candidates = splice_viable (candidates, false, &any_viable_p);
4963 if (complain & tf_error)
4964 error_at (loc, "operands to ?: have different types %qT and %qT",
4965 arg2_type, arg3_type);
4966 return error_mark_node;
4968 cand = tourney (candidates, complain);
4971 if (complain & tf_error)
4973 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4974 print_z_candidates (loc, candidates);
4976 return error_mark_node;
4981 Otherwise, the conversions thus determined are applied, and
4982 the converted operands are used in place of the original
4983 operands for the remainder of this section. */
4984 conv = cand->convs[0];
4985 arg1 = convert_like (conv, arg1, complain);
4986 conv = cand->convs[1];
4987 arg2 = convert_like (conv, arg2, complain);
4988 arg2_type = TREE_TYPE (arg2);
4989 conv = cand->convs[2];
4990 arg3 = convert_like (conv, arg3, complain);
4991 arg3_type = TREE_TYPE (arg3);
4996 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
4997 and function-to-pointer (_conv.func_) standard conversions are
4998 performed on the second and third operands.
5000 We need to force the lvalue-to-rvalue conversion here for class types,
5001 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
5002 that isn't wrapped with a TARGET_EXPR plays havoc with exception
5005 arg2 = force_rvalue (arg2, complain);
5006 if (!CLASS_TYPE_P (arg2_type))
5007 arg2_type = TREE_TYPE (arg2);
5009 arg3 = force_rvalue (arg3, complain);
5010 if (!CLASS_TYPE_P (arg3_type))
5011 arg3_type = TREE_TYPE (arg3);
5013 if (arg2 == error_mark_node || arg3 == error_mark_node)
5014 return error_mark_node;
5018 After those conversions, one of the following shall hold:
5020 --The second and third operands have the same type; the result is of
5022 if (same_type_p (arg2_type, arg3_type))
5023 result_type = arg2_type;
5026 --The second and third operands have arithmetic or enumeration
5027 type; the usual arithmetic conversions are performed to bring
5028 them to a common type, and the result is of that type. */
5029 else if ((ARITHMETIC_TYPE_P (arg2_type)
5030 || UNSCOPED_ENUM_P (arg2_type))
5031 && (ARITHMETIC_TYPE_P (arg3_type)
5032 || UNSCOPED_ENUM_P (arg3_type)))
5034 /* In this case, there is always a common type. */
5035 result_type = type_after_usual_arithmetic_conversions (arg2_type,
5037 if (complain & tf_warning)
5038 do_warn_double_promotion (result_type, arg2_type, arg3_type,
5039 "implicit conversion from %qT to %qT to "
5040 "match other result of conditional",
5043 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
5044 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
5046 if (TREE_CODE (orig_arg2) == CONST_DECL
5047 && TREE_CODE (orig_arg3) == CONST_DECL
5048 && DECL_CONTEXT (orig_arg2) == DECL_CONTEXT (orig_arg3))
5049 /* Two enumerators from the same enumeration can have different
5050 types when the enumeration is still being defined. */;
5051 else if (complain & tf_warning)
5052 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in "
5053 "conditional expression: %qT vs %qT",
5054 arg2_type, arg3_type);
5056 else if (extra_warnings
5057 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
5058 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
5059 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
5060 && !same_type_p (arg2_type,
5061 type_promotes_to (arg3_type)))))
5063 if (complain & tf_warning)
5064 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in "
5065 "conditional expression");
5068 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5069 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5073 --The second and third operands have pointer type, or one has
5074 pointer type and the other is a null pointer constant; pointer
5075 conversions (_conv.ptr_) and qualification conversions
5076 (_conv.qual_) are performed to bring them to their composite
5077 pointer type (_expr.rel_). The result is of the composite
5080 --The second and third operands have pointer to member type, or
5081 one has pointer to member type and the other is a null pointer
5082 constant; pointer to member conversions (_conv.mem_) and
5083 qualification conversions (_conv.qual_) are performed to bring
5084 them to a common type, whose cv-qualification shall match the
5085 cv-qualification of either the second or the third operand.
5086 The result is of the common type. */
5087 else if ((null_ptr_cst_p (arg2)
5088 && TYPE_PTR_OR_PTRMEM_P (arg3_type))
5089 || (null_ptr_cst_p (arg3)
5090 && TYPE_PTR_OR_PTRMEM_P (arg2_type))
5091 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
5092 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type))
5093 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
5095 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
5096 arg3, CPO_CONDITIONAL_EXPR,
5098 if (result_type == error_mark_node)
5099 return error_mark_node;
5100 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5101 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5106 if (complain & tf_error)
5107 error_at (loc, "operands to ?: have different types %qT and %qT",
5108 arg2_type, arg3_type);
5109 return error_mark_node;
5112 if (arg2 == error_mark_node || arg3 == error_mark_node)
5113 return error_mark_node;
5116 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3);
5117 if (!cp_unevaluated_operand)
5118 /* Avoid folding within decltype (c++/42013) and noexcept. */
5119 result = fold_if_not_in_template (result);
5121 /* We can't use result_type below, as fold might have returned a
5126 /* Expand both sides into the same slot, hopefully the target of
5127 the ?: expression. We used to check for TARGET_EXPRs here,
5128 but now we sometimes wrap them in NOP_EXPRs so the test would
5130 if (CLASS_TYPE_P (TREE_TYPE (result)))
5131 result = get_target_expr_sfinae (result, complain);
5132 /* If this expression is an rvalue, but might be mistaken for an
5133 lvalue, we must add a NON_LVALUE_EXPR. */
5134 result = rvalue (result);
5137 result = force_paren_expr (result);
5142 /* Wrapper for above. */
5145 build_conditional_expr (location_t loc, tree arg1, tree arg2, tree arg3,
5146 tsubst_flags_t complain)
5149 bool subtime = timevar_cond_start (TV_OVERLOAD);
5150 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain);
5151 timevar_cond_stop (TV_OVERLOAD, subtime);
5155 /* OPERAND is an operand to an expression. Perform necessary steps
5156 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
5160 prep_operand (tree operand)
5164 if (CLASS_TYPE_P (TREE_TYPE (operand))
5165 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
5166 /* Make sure the template type is instantiated now. */
5167 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
5173 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
5174 OVERLOAD) to the CANDIDATES, returning an updated list of
5175 CANDIDATES. The ARGS are the arguments provided to the call;
5176 if FIRST_ARG is non-null it is the implicit object argument,
5177 otherwise the first element of ARGS is used if needed. The
5178 EXPLICIT_TARGS are explicit template arguments provided.
5179 TEMPLATE_ONLY is true if only template functions should be
5180 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
5181 add_function_candidate. */
5184 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args,
5186 tree explicit_targs, bool template_only,
5187 tree conversion_path, tree access_path,
5189 struct z_candidate **candidates,
5190 tsubst_flags_t complain)
5193 const vec<tree, va_gc> *non_static_args;
5194 bool check_list_ctor;
5195 bool check_converting;
5196 unification_kind_t strict;
5202 /* Precalculate special handling of constructors and conversion ops. */
5203 fn = OVL_CURRENT (fns);
5204 if (DECL_CONV_FN_P (fn))
5206 check_list_ctor = false;
5207 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
5208 if (flags & LOOKUP_NO_CONVERSION)
5209 /* We're doing return_type(x). */
5210 strict = DEDUCE_CONV;
5212 /* We're doing x.operator return_type(). */
5213 strict = DEDUCE_EXACT;
5214 /* [over.match.funcs] For conversion functions, the function
5215 is considered to be a member of the class of the implicit
5216 object argument for the purpose of defining the type of
5217 the implicit object parameter. */
5218 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg));
5222 if (DECL_CONSTRUCTOR_P (fn))
5224 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY);
5225 /* For list-initialization we consider explicit constructors
5226 and complain if one is chosen. */
5228 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR))
5229 == LOOKUP_ONLYCONVERTING);
5233 check_list_ctor = false;
5234 check_converting = false;
5236 strict = DEDUCE_CALL;
5237 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
5241 non_static_args = args;
5243 /* Delay creating the implicit this parameter until it is needed. */
5244 non_static_args = NULL;
5246 for (; fns; fns = OVL_NEXT (fns))
5249 const vec<tree, va_gc> *fn_args;
5251 fn = OVL_CURRENT (fns);
5253 if (check_converting && DECL_NONCONVERTING_P (fn))
5255 if (check_list_ctor && !is_list_ctor (fn))
5258 /* Figure out which set of arguments to use. */
5259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
5261 /* If this function is a non-static member and we didn't get an
5262 implicit object argument, move it out of args. */
5263 if (first_arg == NULL_TREE)
5267 vec<tree, va_gc> *tempvec;
5268 vec_alloc (tempvec, args->length () - 1);
5269 for (ix = 1; args->iterate (ix, &arg); ++ix)
5270 tempvec->quick_push (arg);
5271 non_static_args = tempvec;
5272 first_arg = (*args)[0];
5275 fn_first_arg = first_arg;
5276 fn_args = non_static_args;
5280 /* Otherwise, just use the list of arguments provided. */
5281 fn_first_arg = NULL_TREE;
5285 if (TREE_CODE (fn) == TEMPLATE_DECL)
5286 add_template_candidate (candidates,
5298 else if (!template_only)
5299 add_function_candidate (candidates,
5312 build_new_op_1 (location_t loc, enum tree_code code, int flags, tree arg1,
5313 tree arg2, tree arg3, tree *overload, tsubst_flags_t complain)
5315 struct z_candidate *candidates = 0, *cand;
5316 vec<tree, va_gc> *arglist;
5319 tree result = NULL_TREE;
5320 bool result_valid_p = false;
5321 enum tree_code code2 = NOP_EXPR;
5322 enum tree_code code_orig_arg1 = ERROR_MARK;
5323 enum tree_code code_orig_arg2 = ERROR_MARK;
5329 if (error_operand_p (arg1)
5330 || error_operand_p (arg2)
5331 || error_operand_p (arg3))
5332 return error_mark_node;
5334 if (code == MODIFY_EXPR)
5336 code2 = TREE_CODE (arg3);
5338 fnname = ansi_assopname (code2);
5341 fnname = ansi_opname (code);
5343 arg1 = prep_operand (arg1);
5345 bool memonly = false;
5350 case VEC_DELETE_EXPR:
5352 /* Use build_op_new_call and build_op_delete_call instead. */
5356 /* Use build_op_call instead. */
5359 case TRUTH_ORIF_EXPR:
5360 case TRUTH_ANDIF_EXPR:
5361 case TRUTH_AND_EXPR:
5363 /* These are saved for the sake of warn_logical_operator. */
5364 code_orig_arg1 = TREE_CODE (arg1);
5365 code_orig_arg2 = TREE_CODE (arg2);
5373 /* These are saved for the sake of maybe_warn_bool_compare. */
5374 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1));
5375 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2));
5378 /* =, ->, [], () must be non-static member functions. */
5380 if (code2 != NOP_EXPR)
5391 arg2 = prep_operand (arg2);
5392 arg3 = prep_operand (arg3);
5394 if (code == COND_EXPR)
5395 /* Use build_conditional_expr instead. */
5397 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1))
5398 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2))))
5401 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
5402 arg2 = integer_zero_node;
5404 vec_alloc (arglist, 3);
5405 arglist->quick_push (arg1);
5406 if (arg2 != NULL_TREE)
5407 arglist->quick_push (arg2);
5408 if (arg3 != NULL_TREE)
5409 arglist->quick_push (arg3);
5411 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5412 p = conversion_obstack_alloc (0);
5414 /* Add namespace-scope operators to the list of functions to
5417 add_candidates (lookup_function_nonclass (fnname, arglist,
5419 NULL_TREE, arglist, NULL_TREE,
5420 NULL_TREE, false, NULL_TREE, NULL_TREE,
5421 flags, &candidates, complain);
5425 args[2] = NULL_TREE;
5427 /* Add class-member operators to the candidate set. */
5428 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
5432 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
5433 if (fns == error_mark_node)
5435 result = error_mark_node;
5436 goto user_defined_result_ready;
5439 add_candidates (BASELINK_FUNCTIONS (fns),
5440 NULL_TREE, arglist, NULL_TREE,
5442 BASELINK_BINFO (fns),
5443 BASELINK_ACCESS_BINFO (fns),
5444 flags, &candidates, complain);
5446 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then
5447 only non-member functions that have type T1 or reference to
5448 cv-qualified-opt T1 for the first argument, if the first argument
5449 has an enumeration type, or T2 or reference to cv-qualified-opt
5450 T2 for the second argument, if the the second argument has an
5451 enumeration type. Filter out those that don't match. */
5452 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2)))
5454 struct z_candidate **candp, **next;
5456 for (candp = &candidates; *candp; candp = next)
5458 tree parmlist, parmtype;
5459 int i, nargs = (arg2 ? 2 : 1);
5464 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
5466 for (i = 0; i < nargs; ++i)
5468 parmtype = TREE_VALUE (parmlist);
5470 if (TREE_CODE (parmtype) == REFERENCE_TYPE)
5471 parmtype = TREE_TYPE (parmtype);
5472 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE
5473 && (same_type_ignoring_top_level_qualifiers_p
5474 (TREE_TYPE (args[i]), parmtype)))
5477 parmlist = TREE_CHAIN (parmlist);
5480 /* No argument has an appropriate type, so remove this
5481 candidate function from the list. */
5484 *candp = cand->next;
5490 add_builtin_candidates (&candidates, code, code2, fnname, args,
5497 /* For these, the built-in candidates set is empty
5498 [over.match.oper]/3. We don't want non-strict matches
5499 because exact matches are always possible with built-in
5500 operators. The built-in candidate set for COMPONENT_REF
5501 would be empty too, but since there are no such built-in
5502 operators, we accept non-strict matches for them. */
5511 candidates = splice_viable (candidates, strict_p, &any_viable_p);
5516 case POSTINCREMENT_EXPR:
5517 case POSTDECREMENT_EXPR:
5518 /* Don't try anything fancy if we're not allowed to produce
5520 if (!(complain & tf_error))
5521 return error_mark_node;
5523 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
5524 distinguish between prefix and postfix ++ and
5525 operator++() was used for both, so we allow this with
5529 const char *msg = (flag_permissive)
5530 ? G_("no %<%D(int)%> declared for postfix %qs,"
5531 " trying prefix operator instead")
5532 : G_("no %<%D(int)%> declared for postfix %qs");
5533 permerror (loc, msg, fnname, operator_name_info[code].name);
5536 if (!flag_permissive)
5537 return error_mark_node;
5539 if (code == POSTINCREMENT_EXPR)
5540 code = PREINCREMENT_EXPR;
5542 code = PREDECREMENT_EXPR;
5543 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE,
5544 NULL_TREE, overload, complain);
5547 /* The caller will deal with these. */
5552 result_valid_p = true;
5556 if (complain & tf_error)
5558 /* If one of the arguments of the operator represents
5559 an invalid use of member function pointer, try to report
5560 a meaningful error ... */
5561 if (invalid_nonstatic_memfn_p (arg1, tf_error)
5562 || invalid_nonstatic_memfn_p (arg2, tf_error)
5563 || invalid_nonstatic_memfn_p (arg3, tf_error))
5564 /* We displayed the error message. */;
5567 /* ... Otherwise, report the more generic
5568 "no matching operator found" error */
5569 op_error (loc, code, code2, arg1, arg2, arg3, FALSE);
5570 print_z_candidates (loc, candidates);
5573 result = error_mark_node;
5579 cand = tourney (candidates, complain);
5582 if (complain & tf_error)
5584 op_error (loc, code, code2, arg1, arg2, arg3, TRUE);
5585 print_z_candidates (loc, candidates);
5587 result = error_mark_node;
5589 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
5592 *overload = cand->fn;
5594 if (resolve_args (arglist, complain) == NULL)
5595 result = error_mark_node;
5597 result = build_over_call (cand, LOOKUP_NORMAL, complain);
5601 /* Give any warnings we noticed during overload resolution. */
5602 if (cand->warnings && (complain & tf_warning))
5604 struct candidate_warning *w;
5605 for (w = cand->warnings; w; w = w->next)
5606 joust (cand, w->loser, 1, complain);
5609 /* Check for comparison of different enum types. */
5618 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
5619 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
5620 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
5621 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
5622 && (complain & tf_warning))
5624 warning (OPT_Wenum_compare,
5625 "comparison between %q#T and %q#T",
5626 TREE_TYPE (arg1), TREE_TYPE (arg2));
5633 /* We need to strip any leading REF_BIND so that bitfields
5634 don't cause errors. This should not remove any important
5635 conversions, because builtins don't apply to class
5636 objects directly. */
5637 conv = cand->convs[0];
5638 if (conv->kind == ck_ref_bind)
5639 conv = next_conversion (conv);
5640 arg1 = convert_like (conv, arg1, complain);
5644 conv = cand->convs[1];
5645 if (conv->kind == ck_ref_bind)
5646 conv = next_conversion (conv);
5648 arg2 = decay_conversion (arg2, complain);
5650 /* We need to call warn_logical_operator before
5651 converting arg2 to a boolean_type, but after
5652 decaying an enumerator to its value. */
5653 if (complain & tf_warning)
5654 warn_logical_operator (loc, code, boolean_type_node,
5655 code_orig_arg1, arg1,
5656 code_orig_arg2, arg2);
5658 arg2 = convert_like (conv, arg2, complain);
5662 conv = cand->convs[2];
5663 if (conv->kind == ck_ref_bind)
5664 conv = next_conversion (conv);
5665 arg3 = convert_like (conv, arg3, complain);
5671 user_defined_result_ready:
5673 /* Free all the conversions we allocated. */
5674 obstack_free (&conversion_obstack, p);
5676 if (result || result_valid_p)
5683 return cp_build_modify_expr (arg1, code2, arg2, complain);
5686 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
5688 case TRUTH_ANDIF_EXPR:
5689 case TRUTH_ORIF_EXPR:
5690 case TRUTH_AND_EXPR:
5692 if (complain & tf_warning)
5693 warn_logical_operator (loc, code, boolean_type_node,
5694 code_orig_arg1, arg1, code_orig_arg2, arg2);
5702 if ((complain & tf_warning)
5703 && ((code_orig_arg1 == BOOLEAN_TYPE)
5704 ^ (code_orig_arg2 == BOOLEAN_TYPE)))
5705 maybe_warn_bool_compare (loc, code, arg1, arg2);
5710 case TRUNC_DIV_EXPR:
5715 case TRUNC_MOD_EXPR:
5719 return cp_build_binary_op (loc, code, arg1, arg2, complain);
5721 case UNARY_PLUS_EXPR:
5724 case TRUTH_NOT_EXPR:
5725 case PREINCREMENT_EXPR:
5726 case POSTINCREMENT_EXPR:
5727 case PREDECREMENT_EXPR:
5728 case POSTDECREMENT_EXPR:
5732 return cp_build_unary_op (code, arg1, candidates != 0, complain);
5735 return cp_build_array_ref (input_location, arg1, arg2, complain);
5738 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR,
5742 /* The caller will deal with these. */
5754 /* Wrapper for above. */
5757 build_new_op (location_t loc, enum tree_code code, int flags,
5758 tree arg1, tree arg2, tree arg3,
5759 tree *overload, tsubst_flags_t complain)
5762 bool subtime = timevar_cond_start (TV_OVERLOAD);
5763 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3,
5764 overload, complain);
5765 timevar_cond_stop (TV_OVERLOAD, subtime);
5769 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
5770 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
5773 non_placement_deallocation_fn_p (tree t)
5775 /* A template instance is never a usual deallocation function,
5776 regardless of its signature. */
5777 if (TREE_CODE (t) == TEMPLATE_DECL
5778 || primary_template_instantiation_p (t))
5781 /* If a class T has a member deallocation function named operator delete
5782 with exactly one parameter, then that function is a usual
5783 (non-placement) deallocation function. If class T does not declare
5784 such an operator delete but does declare a member deallocation
5785 function named operator delete with exactly two parameters, the second
5786 of which has type std::size_t (18.2), then this function is a usual
5787 deallocation function. */
5788 bool global = DECL_NAMESPACE_SCOPE_P (t);
5789 t = FUNCTION_ARG_CHAIN (t);
5790 if (t == void_list_node
5791 || (t && same_type_p (TREE_VALUE (t), size_type_node)
5792 && (!global || flag_sized_deallocation)
5793 && TREE_CHAIN (t) == void_list_node))
5798 /* Build a call to operator delete. This has to be handled very specially,
5799 because the restrictions on what signatures match are different from all
5800 other call instances. For a normal delete, only a delete taking (void *)
5801 or (void *, size_t) is accepted. For a placement delete, only an exact
5802 match with the placement new is accepted.
5804 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
5805 ADDR is the pointer to be deleted.
5806 SIZE is the size of the memory block to be deleted.
5807 GLOBAL_P is true if the delete-expression should not consider
5808 class-specific delete operators.
5809 PLACEMENT is the corresponding placement new call, or NULL_TREE.
5811 If this call to "operator delete" is being generated as part to
5812 deallocate memory allocated via a new-expression (as per [expr.new]
5813 which requires that if the initialization throws an exception then
5814 we call a deallocation function), then ALLOC_FN is the allocation
5818 build_op_delete_call (enum tree_code code, tree addr, tree size,
5819 bool global_p, tree placement,
5820 tree alloc_fn, tsubst_flags_t complain)
5822 tree fn = NULL_TREE;
5823 tree fns, fnname, type, t;
5825 if (addr == error_mark_node)
5826 return error_mark_node;
5828 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
5830 fnname = ansi_opname (code);
5832 if (CLASS_TYPE_P (type)
5833 && COMPLETE_TYPE_P (complete_type (type))
5837 If the result of the lookup is ambiguous or inaccessible, or if
5838 the lookup selects a placement deallocation function, the
5839 program is ill-formed.
5841 Therefore, we ask lookup_fnfields to complain about ambiguity. */
5843 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
5844 if (fns == error_mark_node)
5845 return error_mark_node;
5850 if (fns == NULL_TREE)
5851 fns = lookup_name_nonclass (fnname);
5853 /* Strip const and volatile from addr. */
5854 addr = cp_convert (ptr_type_node, addr, complain);
5858 /* "A declaration of a placement deallocation function matches the
5859 declaration of a placement allocation function if it has the same
5860 number of parameters and, after parameter transformations (8.3.5),
5861 all parameter types except the first are identical."
5863 So we build up the function type we want and ask instantiate_type
5864 to get it for us. */
5865 t = FUNCTION_ARG_CHAIN (alloc_fn);
5866 t = tree_cons (NULL_TREE, ptr_type_node, t);
5867 t = build_function_type (void_type_node, t);
5869 fn = instantiate_type (t, fns, tf_none);
5870 if (fn == error_mark_node)
5873 if (BASELINK_P (fn))
5874 fn = BASELINK_FUNCTIONS (fn);
5876 /* "If the lookup finds the two-parameter form of a usual deallocation
5877 function (3.7.4.2) and that function, considered as a placement
5878 deallocation function, would have been selected as a match for the
5879 allocation function, the program is ill-formed." */
5880 if (non_placement_deallocation_fn_p (fn))
5882 /* But if the class has an operator delete (void *), then that is
5883 the usual deallocation function, so we shouldn't complain
5884 about using the operator delete (void *, size_t). */
5885 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5886 t; t = OVL_NEXT (t))
5888 tree elt = OVL_CURRENT (t);
5889 if (non_placement_deallocation_fn_p (elt)
5890 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
5893 if (complain & tf_error)
5895 permerror (0, "non-placement deallocation function %q+D", fn);
5896 permerror (input_location, "selected for placement delete");
5899 return error_mark_node;
5904 /* "Any non-placement deallocation function matches a non-placement
5905 allocation function. If the lookup finds a single matching
5906 deallocation function, that function will be called; otherwise, no
5907 deallocation function will be called." */
5908 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5909 t; t = OVL_NEXT (t))
5911 tree elt = OVL_CURRENT (t);
5912 if (non_placement_deallocation_fn_p (elt))
5915 /* "If a class T has a member deallocation function named
5916 operator delete with exactly one parameter, then that
5917 function is a usual (non-placement) deallocation
5918 function. If class T does not declare such an operator
5919 delete but does declare a member deallocation function named
5920 operator delete with exactly two parameters, the second of
5921 which has type std::size_t (18.2), then this function is a
5922 usual deallocation function."
5924 So in a class (void*) beats (void*, size_t). */
5925 if (DECL_CLASS_SCOPE_P (fn))
5927 if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
5930 /* At global scope (in C++14 and above) the rules are different:
5932 If deallocation function lookup finds both a usual
5933 deallocation function with only a pointer parameter and a
5934 usual deallocation function with both a pointer parameter
5935 and a size parameter, the function to be called is selected
5938 * If the type is complete and if, for the second alternative
5939 (delete array) only, the operand is a pointer to a class
5940 type with a non-trivial destructor or a (possibly
5941 multi-dimensional) array thereof, the function with two
5942 parameters is selected.
5944 * Otherwise, it is unspecified which of the two deallocation
5945 functions is selected. */
5948 bool want_size = COMPLETE_TYPE_P (type);
5949 if (code == VEC_DELETE_EXPR
5950 && !TYPE_VEC_NEW_USES_COOKIE (type))
5951 /* We need a cookie to determine the array size. */
5953 bool have_size = (FUNCTION_ARG_CHAIN (fn) != void_list_node);
5954 if (want_size == have_size)
5960 /* If we have a matching function, call it. */
5963 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5965 /* If the FN is a member function, make sure that it is
5967 if (BASELINK_P (fns))
5968 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn,
5971 /* Core issue 901: It's ok to new a type with deleted delete. */
5972 if (DECL_DELETED_FN (fn) && alloc_fn)
5977 /* The placement args might not be suitable for overload
5978 resolution at this point, so build the call directly. */
5979 int nargs = call_expr_nargs (placement);
5980 tree *argarray = XALLOCAVEC (tree, nargs);
5983 for (i = 1; i < nargs; i++)
5984 argarray[i] = CALL_EXPR_ARG (placement, i);
5985 if (!mark_used (fn, complain) && !(complain & tf_error))
5986 return error_mark_node;
5987 return build_cxx_call (fn, nargs, argarray, complain);
5992 vec<tree, va_gc> *args = make_tree_vector ();
5993 args->quick_push (addr);
5994 if (FUNCTION_ARG_CHAIN (fn) != void_list_node)
5995 args->quick_push (size);
5996 ret = cp_build_function_call_vec (fn, &args, complain);
5997 release_tree_vector (args);
6004 If no unambiguous matching deallocation function can be found,
6005 propagating the exception does not cause the object's memory to
6009 if ((complain & tf_warning)
6011 warning (0, "no corresponding deallocation function for %qD",
6016 if (complain & tf_error)
6017 error ("no suitable %<operator %s%> for %qT",
6018 operator_name_info[(int)code].name, type);
6019 return error_mark_node;
6022 /* If the current scope isn't allowed to access DECL along
6023 BASETYPE_PATH, give an error. The most derived class in
6024 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
6025 the declaration to use in the error diagnostic. */
6028 enforce_access (tree basetype_path, tree decl, tree diag_decl,
6029 tsubst_flags_t complain)
6031 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
6033 if (!accessible_p (basetype_path, decl, true))
6035 if (complain & tf_error)
6037 if (TREE_PRIVATE (decl))
6038 error ("%q+#D is private", diag_decl);
6039 else if (TREE_PROTECTED (decl))
6040 error ("%q+#D is protected", diag_decl);
6042 error ("%q+#D is inaccessible", diag_decl);
6043 error ("within this context");
6051 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
6052 bitwise or of LOOKUP_* values. If any errors are warnings are
6053 generated, set *DIAGNOSTIC_FN to "error" or "warning",
6054 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
6058 build_temp (tree expr, tree type, int flags,
6059 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
6062 vec<tree, va_gc> *args;
6064 savew = warningcount + werrorcount, savee = errorcount;
6065 args = make_tree_vector_single (expr);
6066 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6067 &args, type, flags, complain);
6068 release_tree_vector (args);
6069 if (warningcount + werrorcount > savew)
6070 *diagnostic_kind = DK_WARNING;
6071 else if (errorcount > savee)
6072 *diagnostic_kind = DK_ERROR;
6074 *diagnostic_kind = DK_UNSPECIFIED;
6078 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
6079 EXPR is implicitly converted to type TOTYPE.
6080 FN and ARGNUM are used for diagnostics. */
6083 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
6085 /* Issue warnings about peculiar, but valid, uses of NULL. */
6086 if (expr == null_node && TREE_CODE (totype) != BOOLEAN_TYPE
6087 && ARITHMETIC_TYPE_P (totype))
6089 source_location loc =
6090 expansion_point_location_if_in_system_header (input_location);
6093 warning_at (loc, OPT_Wconversion_null,
6094 "passing NULL to non-pointer argument %P of %qD",
6097 warning_at (loc, OPT_Wconversion_null,
6098 "converting to non-pointer type %qT from NULL", totype);
6101 /* Issue warnings if "false" is converted to a NULL pointer */
6102 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE
6103 && TYPE_PTR_P (totype))
6106 warning_at (input_location, OPT_Wconversion_null,
6107 "converting %<false%> to pointer type for argument %P "
6108 "of %qD", argnum, fn);
6110 warning_at (input_location, OPT_Wconversion_null,
6111 "converting %<false%> to pointer type %qT", totype);
6115 /* We gave a diagnostic during a conversion. If this was in the second
6116 standard conversion sequence of a user-defined conversion sequence, say
6117 which user-defined conversion. */
6120 maybe_print_user_conv_context (conversion *convs)
6122 if (convs->user_conv_p)
6123 for (conversion *t = convs; t; t = next_conversion (t))
6124 if (t->kind == ck_user)
6126 print_z_candidate (0, " after user-defined conversion:",
6132 /* Perform the conversions in CONVS on the expression EXPR. FN and
6133 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
6134 indicates the `this' argument of a method. INNER is nonzero when
6135 being called to continue a conversion chain. It is negative when a
6136 reference binding will be applied, positive otherwise. If
6137 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
6138 conversions will be emitted if appropriate. If C_CAST_P is true,
6139 this conversion is coming from a C-style cast; in that case,
6140 conversions to inaccessible bases are permitted. */
6143 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
6144 int inner, bool issue_conversion_warnings,
6145 bool c_cast_p, tsubst_flags_t complain)
6147 tree totype = convs->type;
6148 diagnostic_t diag_kind;
6150 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
6152 if (convs->bad_p && !(complain & tf_error))
6153 return error_mark_node;
6156 && convs->kind != ck_user
6157 && convs->kind != ck_list
6158 && convs->kind != ck_ambig
6159 && (convs->kind != ck_ref_bind
6160 || (convs->user_conv_p && next_conversion (convs)->bad_p))
6161 && (convs->kind != ck_rvalue
6162 || SCALAR_TYPE_P (totype))
6163 && convs->kind != ck_base)
6165 bool complained = false;
6166 conversion *t = convs;
6168 /* Give a helpful error if this is bad because of excess braces. */
6169 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
6170 && SCALAR_TYPE_P (totype)
6171 && CONSTRUCTOR_NELTS (expr) > 0
6172 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
6174 complained = permerror (loc, "too many braces around initializer "
6176 while (BRACE_ENCLOSED_INITIALIZER_P (expr)
6177 && CONSTRUCTOR_NELTS (expr) == 1)
6178 expr = CONSTRUCTOR_ELT (expr, 0)->value;
6181 /* Give a helpful error if this is bad because a conversion to bool
6182 from std::nullptr_t requires direct-initialization. */
6183 if (NULLPTR_TYPE_P (TREE_TYPE (expr))
6184 && TREE_CODE (totype) == BOOLEAN_TYPE)
6185 complained = permerror (loc, "converting to %qT from %qT requires "
6186 "direct-initialization",
6187 totype, TREE_TYPE (expr));
6189 for (; t ; t = next_conversion (t))
6191 if (t->kind == ck_user && t->cand->reason)
6193 complained = permerror (loc, "invalid user-defined conversion "
6194 "from %qT to %qT", TREE_TYPE (expr),
6197 print_z_candidate (loc, "candidate is:", t->cand);
6198 expr = convert_like_real (t, expr, fn, argnum, 1,
6199 /*issue_conversion_warnings=*/false,
6202 if (convs->kind == ck_ref_bind)
6203 expr = convert_to_reference (totype, expr, CONV_IMPLICIT,
6204 LOOKUP_NORMAL, NULL_TREE,
6207 expr = cp_convert (totype, expr, complain);
6208 if (complained && fn)
6209 inform (DECL_SOURCE_LOCATION (fn),
6210 " initializing argument %P of %qD", argnum, fn);
6213 else if (t->kind == ck_user || !t->bad_p)
6215 expr = convert_like_real (t, expr, fn, argnum, 1,
6216 /*issue_conversion_warnings=*/false,
6221 else if (t->kind == ck_ambig)
6222 return convert_like_real (t, expr, fn, argnum, 1,
6223 /*issue_conversion_warnings=*/false,
6226 else if (t->kind == ck_identity)
6230 complained = permerror (loc, "invalid conversion from %qT to %qT",
6231 TREE_TYPE (expr), totype);
6232 if (complained && fn)
6233 inform (DECL_SOURCE_LOCATION (fn),
6234 " initializing argument %P of %qD", argnum, fn);
6236 return cp_convert (totype, expr, complain);
6239 if (issue_conversion_warnings && (complain & tf_warning))
6240 conversion_null_warnings (totype, expr, fn, argnum);
6242 switch (convs->kind)
6246 struct z_candidate *cand = convs->cand;
6247 tree convfn = cand->fn;
6250 /* When converting from an init list we consider explicit
6251 constructors, but actually trying to call one is an error. */
6252 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
6253 && BRACE_ENCLOSED_INITIALIZER_P (expr)
6254 /* Unless this is for direct-list-initialization. */
6255 && !CONSTRUCTOR_IS_DIRECT_INIT (expr))
6257 if (!(complain & tf_error))
6258 return error_mark_node;
6259 error ("converting to %qT from initializer list would use "
6260 "explicit constructor %qD", totype, convfn);
6263 /* If we're initializing from {}, it's value-initialization. */
6264 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
6265 && CONSTRUCTOR_NELTS (expr) == 0
6266 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
6268 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr);
6269 expr = build_value_init (totype, complain);
6270 expr = get_target_expr_sfinae (expr, complain);
6271 if (expr != error_mark_node)
6273 TARGET_EXPR_LIST_INIT_P (expr) = true;
6274 TARGET_EXPR_DIRECT_INIT_P (expr) = direct;
6279 expr = mark_rvalue_use (expr);
6281 /* Set user_conv_p on the argument conversions, so rvalue/base
6282 handling knows not to allow any more UDCs. */
6283 for (i = 0; i < cand->num_convs; ++i)
6284 cand->convs[i]->user_conv_p = true;
6286 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
6288 /* If this is a constructor or a function returning an aggr type,
6289 we need to build up a TARGET_EXPR. */
6290 if (DECL_CONSTRUCTOR_P (convfn))
6292 expr = build_cplus_new (totype, expr, complain);
6294 /* Remember that this was list-initialization. */
6295 if (convs->check_narrowing && expr != error_mark_node)
6296 TARGET_EXPR_LIST_INIT_P (expr) = true;
6302 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
6304 int nelts = CONSTRUCTOR_NELTS (expr);
6306 expr = build_value_init (totype, complain);
6307 else if (nelts == 1)
6308 expr = CONSTRUCTOR_ELT (expr, 0)->value;
6312 expr = mark_rvalue_use (expr);
6314 if (type_unknown_p (expr))
6315 expr = instantiate_type (totype, expr, complain);
6316 /* Convert a constant to its underlying value, unless we are
6317 about to bind it to a reference, in which case we need to
6318 leave it as an lvalue. */
6321 expr = scalar_constant_value (expr);
6322 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
6323 /* If __null has been converted to an integer type, we do not
6324 want to warn about uses of EXPR as an integer, rather than
6326 expr = build_int_cst (totype, 0);
6330 /* We leave bad_p off ck_ambig because overload resolution considers
6331 it valid, it just fails when we try to perform it. So we need to
6332 check complain here, too. */
6333 if (complain & tf_error)
6335 /* Call build_user_type_conversion again for the error. */
6336 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL,
6339 inform (input_location, " initializing argument %P of %q+D",
6342 return error_mark_node;
6346 /* Conversion to std::initializer_list<T>. */
6347 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
6348 tree new_ctor = build_constructor (init_list_type_node, NULL);
6349 unsigned len = CONSTRUCTOR_NELTS (expr);
6350 tree array, val, field;
6351 vec<constructor_elt, va_gc> *vec = NULL;
6354 /* Convert all the elements. */
6355 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
6357 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
6358 1, false, false, complain);
6359 if (sub == error_mark_node)
6361 if (!BRACE_ENCLOSED_INITIALIZER_P (val)
6362 && !check_narrowing (TREE_TYPE (sub), val, complain))
6363 return error_mark_node;
6364 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
6365 if (!TREE_CONSTANT (sub))
6366 TREE_CONSTANT (new_ctor) = false;
6368 /* Build up the array. */
6369 elttype = cp_build_qualified_type
6370 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
6371 array = build_array_of_n_type (elttype, len);
6372 array = finish_compound_literal (array, new_ctor, complain);
6373 /* Take the address explicitly rather than via decay_conversion
6374 to avoid the error about taking the address of a temporary. */
6375 array = cp_build_addr_expr (array, complain);
6376 array = cp_convert (build_pointer_type (elttype), array, complain);
6377 if (array == error_mark_node)
6378 return error_mark_node;
6380 /* Build up the initializer_list object. */
6381 totype = complete_type (totype);
6382 field = next_initializable_field (TYPE_FIELDS (totype));
6383 CONSTRUCTOR_APPEND_ELT (vec, field, array);
6384 field = next_initializable_field (DECL_CHAIN (field));
6385 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
6386 new_ctor = build_constructor (totype, vec);
6387 return get_target_expr_sfinae (new_ctor, complain);
6391 if (TREE_CODE (totype) == COMPLEX_TYPE)
6393 tree real = CONSTRUCTOR_ELT (expr, 0)->value;
6394 tree imag = CONSTRUCTOR_ELT (expr, 1)->value;
6395 real = perform_implicit_conversion (TREE_TYPE (totype),
6397 imag = perform_implicit_conversion (TREE_TYPE (totype),
6399 expr = build2 (COMPLEX_EXPR, totype, real, imag);
6400 return fold_if_not_in_template (expr);
6402 expr = reshape_init (totype, expr, complain);
6403 expr = get_target_expr_sfinae (digest_init (totype, expr, complain),
6405 if (expr != error_mark_node)
6406 TARGET_EXPR_LIST_INIT_P (expr) = true;
6413 expr = convert_like_real (next_conversion (convs), expr, fn, argnum,
6414 convs->kind == ck_ref_bind ? -1 : 1,
6415 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
6418 if (expr == error_mark_node)
6419 return error_mark_node;
6421 switch (convs->kind)
6424 expr = decay_conversion (expr, complain);
6425 if (expr == error_mark_node)
6426 return error_mark_node;
6428 if (! MAYBE_CLASS_TYPE_P (totype))
6430 /* Else fall through. */
6432 if (convs->kind == ck_base && !convs->need_temporary_p)
6434 /* We are going to bind a reference directly to a base-class
6435 subobject of EXPR. */
6436 /* Build an expression for `*((base*) &expr)'. */
6437 expr = convert_to_base (expr, totype,
6438 !c_cast_p, /*nonnull=*/true, complain);
6442 /* Copy-initialization where the cv-unqualified version of the source
6443 type is the same class as, or a derived class of, the class of the
6444 destination [is treated as direct-initialization]. [dcl.init] */
6445 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
6446 if (convs->user_conv_p)
6447 /* This conversion is being done in the context of a user-defined
6448 conversion (i.e. the second step of copy-initialization), so
6449 don't allow any more. */
6450 flags |= LOOKUP_NO_CONVERSION;
6451 if (convs->rvaluedness_matches_p)
6452 flags |= LOOKUP_PREFER_RVALUE;
6453 if (TREE_CODE (expr) == TARGET_EXPR
6454 && TARGET_EXPR_LIST_INIT_P (expr))
6455 /* Copy-list-initialization doesn't actually involve a copy. */
6457 expr = build_temp (expr, totype, flags, &diag_kind, complain);
6458 if (diag_kind && complain)
6460 maybe_print_user_conv_context (convs);
6462 inform (DECL_SOURCE_LOCATION (fn),
6463 " initializing argument %P of %qD", argnum, fn);
6466 return build_cplus_new (totype, expr, complain);
6470 tree ref_type = totype;
6472 if (convs->bad_p && !next_conversion (convs)->bad_p)
6474 tree extype = TREE_TYPE (expr);
6475 if (TYPE_REF_IS_RVALUE (ref_type)
6476 && real_lvalue_p (expr))
6477 error_at (loc, "cannot bind %qT lvalue to %qT",
6479 else if (!TYPE_REF_IS_RVALUE (ref_type) && !real_lvalue_p (expr)
6480 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
6481 error_at (loc, "invalid initialization of non-const reference of "
6482 "type %qT from an rvalue of type %qT", totype, extype);
6483 else if (!reference_compatible_p (TREE_TYPE (totype), extype))
6484 error_at (loc, "binding %qT to reference of type %qT "
6485 "discards qualifiers", extype, totype);
6488 maybe_print_user_conv_context (convs);
6490 inform (input_location,
6491 " initializing argument %P of %q+D", argnum, fn);
6492 return error_mark_node;
6495 /* If necessary, create a temporary.
6497 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
6498 that need temporaries, even when their types are reference
6499 compatible with the type of reference being bound, so the
6500 upcoming call to cp_build_addr_expr doesn't fail. */
6501 if (convs->need_temporary_p
6502 || TREE_CODE (expr) == CONSTRUCTOR
6503 || TREE_CODE (expr) == VA_ARG_EXPR)
6505 /* Otherwise, a temporary of type "cv1 T1" is created and
6506 initialized from the initializer expression using the rules
6507 for a non-reference copy-initialization (8.5). */
6509 tree type = TREE_TYPE (ref_type);
6510 cp_lvalue_kind lvalue = real_lvalue_p (expr);
6512 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6513 (type, next_conversion (convs)->type));
6514 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
6515 && !TYPE_REF_IS_RVALUE (ref_type))
6517 /* If the reference is volatile or non-const, we
6518 cannot create a temporary. */
6519 if (lvalue & clk_bitfield)
6520 error_at (loc, "cannot bind bitfield %qE to %qT",
6522 else if (lvalue & clk_packed)
6523 error_at (loc, "cannot bind packed field %qE to %qT",
6526 error_at (loc, "cannot bind rvalue %qE to %qT",
6528 return error_mark_node;
6530 /* If the source is a packed field, and we must use a copy
6531 constructor, then building the target expr will require
6532 binding the field to the reference parameter to the
6533 copy constructor, and we'll end up with an infinite
6534 loop. If we can use a bitwise copy, then we'll be
6536 if ((lvalue & clk_packed)
6537 && CLASS_TYPE_P (type)
6538 && type_has_nontrivial_copy_init (type))
6540 error_at (loc, "cannot bind packed field %qE to %qT",
6542 return error_mark_node;
6544 if (lvalue & clk_bitfield)
6546 expr = convert_bitfield_to_declared_type (expr);
6547 expr = fold_convert (type, expr);
6549 expr = build_target_expr_with_type (expr, type, complain);
6552 /* Take the address of the thing to which we will bind the
6554 expr = cp_build_addr_expr (expr, complain);
6555 if (expr == error_mark_node)
6556 return error_mark_node;
6558 /* Convert it to a pointer to the type referred to by the
6559 reference. This will adjust the pointer if a derived to
6560 base conversion is being performed. */
6561 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
6563 /* Convert the pointer to the desired reference type. */
6564 return build_nop (ref_type, expr);
6568 return decay_conversion (expr, complain);
6571 /* Warn about deprecated conversion if appropriate. */
6572 string_conv_p (totype, expr, 1);
6577 expr = convert_to_base (expr, totype, !c_cast_p,
6578 /*nonnull=*/false, complain);
6579 return build_nop (totype, expr);
6582 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
6583 c_cast_p, complain);
6589 if (convs->check_narrowing
6590 && !check_narrowing (totype, expr, complain))
6591 return error_mark_node;
6593 if (issue_conversion_warnings)
6594 expr = cp_convert_and_check (totype, expr, complain);
6596 expr = cp_convert (totype, expr, complain);
6601 /* ARG is being passed to a varargs function. Perform any conversions
6602 required. Return the converted value. */
6605 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain)
6608 location_t loc = EXPR_LOC_OR_LOC (arg, input_location);
6612 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
6613 standard conversions are performed. */
6614 arg = decay_conversion (arg, complain);
6615 arg_type = TREE_TYPE (arg);
6618 If the argument has integral or enumeration type that is subject
6619 to the integral promotions (_conv.prom_), or a floating point
6620 type that is subject to the floating point promotion
6621 (_conv.fpprom_), the value of the argument is converted to the
6622 promoted type before the call. */
6623 if (TREE_CODE (arg_type) == REAL_TYPE
6624 && (TYPE_PRECISION (arg_type)
6625 < TYPE_PRECISION (double_type_node))
6626 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
6628 if ((complain & tf_warning)
6629 && warn_double_promotion && !c_inhibit_evaluation_warnings)
6630 warning_at (loc, OPT_Wdouble_promotion,
6631 "implicit conversion from %qT to %qT when passing "
6632 "argument to function",
6633 arg_type, double_type_node);
6634 arg = convert_to_real (double_type_node, arg);
6636 else if (NULLPTR_TYPE_P (arg_type))
6637 arg = null_pointer_node;
6638 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
6640 if (SCOPED_ENUM_P (arg_type))
6642 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg,
6644 prom = cp_perform_integral_promotions (prom, complain);
6645 if (abi_version_crosses (6)
6646 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type)
6647 && (complain & tf_warning))
6648 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as "
6649 "%qT before -fabi-version=6, %qT after", arg_type,
6650 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type));
6651 if (!abi_version_at_least (6))
6655 arg = cp_perform_integral_promotions (arg, complain);
6658 arg = require_complete_type_sfinae (arg, complain);
6659 arg_type = TREE_TYPE (arg);
6661 if (arg != error_mark_node
6662 /* In a template (or ill-formed code), we can have an incomplete type
6663 even after require_complete_type_sfinae, in which case we don't know
6664 whether it has trivial copy or not. */
6665 && COMPLETE_TYPE_P (arg_type))
6667 /* Build up a real lvalue-to-rvalue conversion in case the
6668 copy constructor is trivial but not callable. */
6669 if (!cp_unevaluated_operand && CLASS_TYPE_P (arg_type))
6670 force_rvalue (arg, complain);
6672 /* [expr.call] 5.2.2/7:
6673 Passing a potentially-evaluated argument of class type (Clause 9)
6674 with a non-trivial copy constructor or a non-trivial destructor
6675 with no corresponding parameter is conditionally-supported, with
6676 implementation-defined semantics.
6678 We support it as pass-by-invisible-reference, just like a normal
6681 If the call appears in the context of a sizeof expression,
6682 it is not potentially-evaluated. */
6683 if (cp_unevaluated_operand == 0
6684 && (type_has_nontrivial_copy_init (arg_type)
6685 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
6687 if (complain & tf_warning)
6688 warning (OPT_Wconditionally_supported,
6689 "passing objects of non-trivially-copyable "
6690 "type %q#T through %<...%> is conditionally supported",
6692 return cp_build_addr_expr (arg, complain);
6699 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
6702 build_x_va_arg (source_location loc, tree expr, tree type)
6704 if (processing_template_decl)
6706 tree r = build_min (VA_ARG_EXPR, type, expr);
6707 SET_EXPR_LOCATION (r, loc);
6711 type = complete_type_or_else (type, NULL_TREE);
6713 if (expr == error_mark_node || !type)
6714 return error_mark_node;
6716 expr = mark_lvalue_use (expr);
6718 if (TREE_CODE (type) == REFERENCE_TYPE)
6720 error ("cannot receive reference type %qT through %<...%>", type);
6721 return error_mark_node;
6724 if (type_has_nontrivial_copy_init (type)
6725 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6727 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat
6728 it as pass by invisible reference. */
6729 warning_at (loc, OPT_Wconditionally_supported,
6730 "receiving objects of non-trivially-copyable type %q#T "
6731 "through %<...%> is conditionally-supported", type);
6733 tree ref = cp_build_reference_type (type, false);
6734 expr = build_va_arg (loc, expr, ref);
6735 return convert_from_reference (expr);
6738 return build_va_arg (loc, expr, type);
6741 /* TYPE has been given to va_arg. Apply the default conversions which
6742 would have happened when passed via ellipsis. Return the promoted
6743 type, or the passed type if there is no change. */
6746 cxx_type_promotes_to (tree type)
6750 /* Perform the array-to-pointer and function-to-pointer
6752 type = type_decays_to (type);
6754 promote = type_promotes_to (type);
6755 if (same_type_p (type, promote))
6761 /* ARG is a default argument expression being passed to a parameter of
6762 the indicated TYPE, which is a parameter to FN. PARMNUM is the
6763 zero-based argument number. Do any required conversions. Return
6764 the converted value. */
6766 static GTY(()) vec<tree, va_gc> *default_arg_context;
6768 push_defarg_context (tree fn)
6769 { vec_safe_push (default_arg_context, fn); }
6772 pop_defarg_context (void)
6773 { default_arg_context->pop (); }
6776 convert_default_arg (tree type, tree arg, tree fn, int parmnum,
6777 tsubst_flags_t complain)
6782 /* See through clones. */
6783 fn = DECL_ORIGIN (fn);
6785 /* Detect recursion. */
6786 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t)
6789 if (complain & tf_error)
6790 error ("recursive evaluation of default argument for %q#D", fn);
6791 return error_mark_node;
6794 /* If the ARG is an unparsed default argument expression, the
6795 conversion cannot be performed. */
6796 if (TREE_CODE (arg) == DEFAULT_ARG)
6798 if (complain & tf_error)
6799 error ("call to %qD uses the default argument for parameter %P, which "
6800 "is not yet defined", fn, parmnum);
6801 return error_mark_node;
6804 push_defarg_context (fn);
6806 if (fn && DECL_TEMPLATE_INFO (fn))
6807 arg = tsubst_default_argument (fn, type, arg, complain);
6813 The names in the expression are bound, and the semantic
6814 constraints are checked, at the point where the default
6815 expressions appears.
6817 we must not perform access checks here. */
6818 push_deferring_access_checks (dk_no_check);
6819 /* We must make a copy of ARG, in case subsequent processing
6820 alters any part of it. */
6821 arg = break_out_target_exprs (arg);
6822 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
6823 ICR_DEFAULT_ARGUMENT, fn, parmnum,
6825 arg = convert_for_arg_passing (type, arg, complain);
6826 pop_deferring_access_checks();
6828 pop_defarg_context ();
6833 /* Returns the type which will really be used for passing an argument of
6837 type_passed_as (tree type)
6839 /* Pass classes with copy ctors by invisible reference. */
6840 if (TREE_ADDRESSABLE (type))
6842 type = build_reference_type (type);
6843 /* There are no other pointers to this temporary. */
6844 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
6846 else if (targetm.calls.promote_prototypes (type)
6847 && INTEGRAL_TYPE_P (type)
6848 && COMPLETE_TYPE_P (type)
6849 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
6850 type = integer_type_node;
6855 /* Actually perform the appropriate conversion. */
6858 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain)
6862 /* If VAL is a bitfield, then -- since it has already been converted
6863 to TYPE -- it cannot have a precision greater than TYPE.
6865 If it has a smaller precision, we must widen it here. For
6866 example, passing "int f:3;" to a function expecting an "int" will
6867 not result in any conversion before this point.
6869 If the precision is the same we must not risk widening. For
6870 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
6871 often have type "int", even though the C++ type for the field is
6872 "long long". If the value is being passed to a function
6873 expecting an "int", then no conversions will be required. But,
6874 if we call convert_bitfield_to_declared_type, the bitfield will
6875 be converted to "long long". */
6876 bitfield_type = is_bitfield_expr_with_lowered_type (val);
6878 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
6879 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
6881 if (val == error_mark_node)
6883 /* Pass classes with copy ctors by invisible reference. */
6884 else if (TREE_ADDRESSABLE (type))
6885 val = build1 (ADDR_EXPR, build_reference_type (type), val);
6886 else if (targetm.calls.promote_prototypes (type)
6887 && INTEGRAL_TYPE_P (type)
6888 && COMPLETE_TYPE_P (type)
6889 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
6890 val = cp_perform_integral_promotions (val, complain);
6891 if ((complain & tf_warning)
6892 && warn_suggest_attribute_format)
6894 tree rhstype = TREE_TYPE (val);
6895 const enum tree_code coder = TREE_CODE (rhstype);
6896 const enum tree_code codel = TREE_CODE (type);
6897 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6899 && check_missing_format_attribute (type, rhstype))
6900 warning (OPT_Wsuggest_attribute_format,
6901 "argument of function call might be a candidate for a format attribute");
6906 /* Returns true iff FN is a function with magic varargs, i.e. ones for
6907 which no conversions at all should be done. This is true for some
6908 builtins which don't act like normal functions. */
6911 magic_varargs_p (tree fn)
6913 if (flag_cilkplus && is_cilkplus_reduce_builtin (fn) != BUILT_IN_NONE)
6916 if (DECL_BUILT_IN (fn))
6917 switch (DECL_FUNCTION_CODE (fn))
6919 case BUILT_IN_CLASSIFY_TYPE:
6920 case BUILT_IN_CONSTANT_P:
6921 case BUILT_IN_NEXT_ARG:
6922 case BUILT_IN_VA_START:
6926 return lookup_attribute ("type generic",
6927 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
6933 /* Returns the decl of the dispatcher function if FN is a function version. */
6936 get_function_version_dispatcher (tree fn)
6938 tree dispatcher_decl = NULL;
6940 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
6941 && DECL_FUNCTION_VERSIONED (fn));
6943 gcc_assert (targetm.get_function_versions_dispatcher);
6944 dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
6946 if (dispatcher_decl == NULL)
6948 error_at (input_location, "use of multiversioned function "
6949 "without a default");
6953 retrofit_lang_decl (dispatcher_decl);
6954 gcc_assert (dispatcher_decl != NULL);
6955 return dispatcher_decl;
6958 /* fn is a function version dispatcher that is marked used. Mark all the
6959 semantically identical function versions it will dispatch as used. */
6962 mark_versions_used (tree fn)
6964 struct cgraph_node *node;
6965 struct cgraph_function_version_info *node_v;
6966 struct cgraph_function_version_info *it_v;
6968 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6970 node = cgraph_node::get (fn);
6974 gcc_assert (node->dispatcher_function);
6976 node_v = node->function_version ();
6980 /* All semantically identical versions are chained. Traverse and mark each
6981 one of them as used. */
6982 it_v = node_v->next;
6983 while (it_v != NULL)
6985 mark_used (it_v->this_node->decl);
6990 /* Build a call to "the copy constructor" for the type of A, even if it
6991 wouldn't be selected by normal overload resolution. Used for
6995 call_copy_ctor (tree a, tsubst_flags_t complain)
6997 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a));
6998 tree binfo = TYPE_BINFO (ctype);
6999 tree copy = get_copy_ctor (ctype, complain);
7000 copy = build_baselink (binfo, binfo, copy, NULL_TREE);
7001 tree ob = build_dummy_object (ctype);
7002 vec<tree, va_gc>* args = make_tree_vector_single (a);
7003 tree r = build_new_method_call (ob, copy, &args, NULL_TREE,
7004 LOOKUP_NORMAL, NULL, complain);
7005 release_tree_vector (args);
7009 /* Return true iff T refers to a base field. */
7012 is_base_field_ref (tree t)
7015 if (TREE_CODE (t) == ADDR_EXPR)
7016 t = TREE_OPERAND (t, 0);
7017 if (TREE_CODE (t) == COMPONENT_REF)
7018 t = TREE_OPERAND (t, 1);
7019 if (TREE_CODE (t) == FIELD_DECL)
7020 return DECL_FIELD_IS_BASE (t);
7024 /* We can't elide a copy from a function returning by value to a base
7025 subobject, as the callee might clobber tail padding. Return true iff this
7026 could be that case. */
7029 unsafe_copy_elision_p (tree target, tree exp)
7031 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
7032 /* It's safe to elide the copy for a class with no tail padding. */
7033 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type)))
7035 /* It's safe to elide the copy if we aren't initializing a base object. */
7036 if (!is_base_field_ref (target))
7038 tree init = TARGET_EXPR_INITIAL (exp);
7039 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */
7040 while (TREE_CODE (init) == COMPOUND_EXPR)
7041 init = TREE_OPERAND (init, 1);
7042 return (TREE_CODE (init) == AGGR_INIT_EXPR
7043 && !AGGR_INIT_VIA_CTOR_P (init));
7046 /* Subroutine of the various build_*_call functions. Overload resolution
7047 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
7048 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
7049 bitmask of various LOOKUP_* flags which apply to the call itself. */
7052 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
7055 const vec<tree, va_gc> *args = cand->args;
7056 tree first_arg = cand->first_arg;
7057 conversion **convs = cand->convs;
7059 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
7064 unsigned int arg_index = 0;
7068 bool already_used = false;
7070 /* In a template, there is no need to perform all of the work that
7071 is normally done. We are only interested in the type of the call
7072 expression, i.e., the return type of the function. Any semantic
7073 errors will be deferred until the template is instantiated. */
7074 if (processing_template_decl)
7078 const tree *argarray;
7081 return_type = TREE_TYPE (TREE_TYPE (fn));
7082 nargs = vec_safe_length (args);
7083 if (first_arg == NULL_TREE)
7084 argarray = args->address ();
7092 alcarray = XALLOCAVEC (tree, nargs);
7093 alcarray[0] = build_this (first_arg);
7094 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
7095 alcarray[ix + 1] = arg;
7096 argarray = alcarray;
7099 addr = build_addr_func (fn, complain);
7100 if (addr == error_mark_node)
7101 return error_mark_node;
7102 expr = build_call_array_loc (input_location, return_type,
7103 addr, nargs, argarray);
7104 if (TREE_THIS_VOLATILE (fn) && cfun)
7105 current_function_returns_abnormally = 1;
7106 return convert_from_reference (expr);
7109 /* Give any warnings we noticed during overload resolution. */
7110 if (cand->warnings && (complain & tf_warning))
7112 struct candidate_warning *w;
7113 for (w = cand->warnings; w; w = w->next)
7114 joust (cand, w->loser, 1, complain);
7117 /* Make =delete work with SFINAE. */
7118 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
7119 return error_mark_node;
7121 if (DECL_FUNCTION_MEMBER_P (fn))
7124 /* If FN is a template function, two cases must be considered.
7129 template <class T> void f();
7131 template <class T> struct B {
7135 struct C : A, B<int> {
7137 using B<int>::g; // #2
7140 In case #1 where `A::f' is a member template, DECL_ACCESS is
7141 recorded in the primary template but not in its specialization.
7142 We check access of FN using its primary template.
7144 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
7145 because it is a member of class template B, DECL_ACCESS is
7146 recorded in the specialization `B<int>::g'. We cannot use its
7147 primary template because `B<T>::g' and `B<int>::g' may have
7148 different access. */
7149 if (DECL_TEMPLATE_INFO (fn)
7150 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
7151 access_fn = DECL_TI_TEMPLATE (fn);
7154 if (!perform_or_defer_access_check (cand->access_path, access_fn,
7156 return error_mark_node;
7159 /* If we're checking for implicit delete, don't bother with argument
7161 if (flags & LOOKUP_SPECULATIVE)
7163 if (DECL_DELETED_FN (fn))
7165 if (complain & tf_error)
7167 return error_mark_node;
7169 if (cand->viable == 1)
7171 else if (!(complain & tf_error))
7172 /* Reject bad conversions now. */
7173 return error_mark_node;
7174 /* else continue to get conversion error. */
7177 /* N3276 magic doesn't apply to nested calls. */
7178 int decltype_flag = (complain & tf_decltype);
7179 complain &= ~tf_decltype;
7181 /* Find maximum size of vector to hold converted arguments. */
7182 parmlen = list_length (parm);
7183 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0);
7184 if (parmlen > nargs)
7186 argarray = XALLOCAVEC (tree, nargs);
7188 /* The implicit parameters to a constructor are not considered by overload
7189 resolution, and must be of the proper type. */
7190 if (DECL_CONSTRUCTOR_P (fn))
7193 if (first_arg != NULL_TREE)
7195 object_arg = first_arg;
7196 first_arg = NULL_TREE;
7200 object_arg = (*args)[arg_index];
7203 argarray[j++] = build_this (object_arg);
7204 parm = TREE_CHAIN (parm);
7205 /* We should never try to call the abstract constructor. */
7206 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
7208 if (DECL_HAS_VTT_PARM_P (fn))
7210 argarray[j++] = (*args)[arg_index];
7212 parm = TREE_CHAIN (parm);
7215 /* Bypass access control for 'this' parameter. */
7216 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
7218 tree parmtype = TREE_VALUE (parm);
7219 tree arg = build_this (first_arg != NULL_TREE
7221 : (*args)[arg_index]);
7222 tree argtype = TREE_TYPE (arg);
7226 if (convs[i]->bad_p)
7228 if (complain & tf_error)
7230 if (permerror (input_location, "passing %qT as %<this%> "
7231 "argument discards qualifiers",
7232 TREE_TYPE (argtype)))
7233 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn);
7236 return error_mark_node;
7239 /* See if the function member or the whole class type is declared
7240 final and the call can be devirtualized. */
7241 if (DECL_FINAL_P (fn)
7242 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn))))
7243 flags |= LOOKUP_NONVIRTUAL;
7245 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
7246 X is called for an object that is not of type X, or of a type
7247 derived from X, the behavior is undefined.
7249 So we can assume that anything passed as 'this' is non-null, and
7250 optimize accordingly. */
7251 gcc_assert (TYPE_PTR_P (parmtype));
7252 /* Convert to the base in which the function was declared. */
7253 gcc_assert (cand->conversion_path != NULL_TREE);
7254 converted_arg = build_base_path (PLUS_EXPR,
7256 cand->conversion_path,
7258 /* Check that the base class is accessible. */
7259 if (!accessible_base_p (TREE_TYPE (argtype),
7260 BINFO_TYPE (cand->conversion_path), true))
7262 if (complain & tf_error)
7263 error ("%qT is not an accessible base of %qT",
7264 BINFO_TYPE (cand->conversion_path),
7265 TREE_TYPE (argtype));
7267 return error_mark_node;
7269 /* If fn was found by a using declaration, the conversion path
7270 will be to the derived class, not the base declaring fn. We
7271 must convert from derived to base. */
7272 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
7273 TREE_TYPE (parmtype), ba_unique,
7275 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
7276 base_binfo, 1, complain);
7278 argarray[j++] = converted_arg;
7279 parm = TREE_CHAIN (parm);
7280 if (first_arg != NULL_TREE)
7281 first_arg = NULL_TREE;
7288 gcc_assert (first_arg == NULL_TREE);
7289 for (; arg_index < vec_safe_length (args) && parm;
7290 parm = TREE_CHAIN (parm), ++arg_index, ++i)
7292 tree type = TREE_VALUE (parm);
7293 tree arg = (*args)[arg_index];
7294 bool conversion_warning = true;
7298 /* If the argument is NULL and used to (implicitly) instantiate a
7299 template function (and bind one of the template arguments to
7300 the type of 'long int'), we don't want to warn about passing NULL
7301 to non-pointer argument.
7302 For example, if we have this template function:
7304 template<typename T> void func(T x) {}
7306 we want to warn (when -Wconversion is enabled) in this case:
7312 but not in this case:
7318 if (arg == null_node
7319 && DECL_TEMPLATE_INFO (fn)
7320 && cand->template_decl
7321 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS))
7322 conversion_warning = false;
7324 /* Warn about initializer_list deduction that isn't currently in the
7326 if (cxx_dialect > cxx98
7327 && flag_deduce_init_list
7328 && cand->template_decl
7329 && is_std_init_list (non_reference (type))
7330 && BRACE_ENCLOSED_INITIALIZER_P (arg))
7332 tree tmpl = TI_TEMPLATE (cand->template_decl);
7333 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
7334 tree patparm = get_pattern_parm (realparm, tmpl);
7335 tree pattype = TREE_TYPE (patparm);
7336 if (PACK_EXPANSION_P (pattype))
7337 pattype = PACK_EXPANSION_PATTERN (pattype);
7338 pattype = non_reference (pattype);
7340 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
7341 && (cand->explicit_targs == NULL_TREE
7342 || (TREE_VEC_LENGTH (cand->explicit_targs)
7343 <= TEMPLATE_TYPE_IDX (pattype))))
7345 pedwarn (input_location, 0, "deducing %qT as %qT",
7346 non_reference (TREE_TYPE (patparm)),
7347 non_reference (type));
7348 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
7349 pedwarn (input_location, 0,
7350 " (you can disable this with -fno-deduce-init-list)");
7353 val = convert_like_with_context (conv, arg, fn, i - is_method,
7356 : complain & (~tf_warning));
7358 val = convert_for_arg_passing (type, val, complain);
7360 if (val == error_mark_node)
7361 return error_mark_node;
7363 argarray[j++] = val;
7366 /* Default arguments */
7367 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
7369 if (TREE_VALUE (parm) == error_mark_node)
7370 return error_mark_node;
7371 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
7372 TREE_PURPOSE (parm),
7378 for (; arg_index < vec_safe_length (args); ++arg_index)
7380 tree a = (*args)[arg_index];
7381 if (magic_varargs_p (fn))
7382 /* Do no conversions for magic varargs. */
7383 a = mark_type_use (a);
7384 else if (DECL_CONSTRUCTOR_P (fn)
7385 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn),
7388 /* Avoid infinite recursion trying to call A(...). */
7389 if (complain & tf_error)
7390 /* Try to call the actual copy constructor for a good error. */
7391 call_copy_ctor (a, complain);
7392 return error_mark_node;
7395 a = convert_arg_to_ellipsis (a, complain);
7399 gcc_assert (j <= nargs);
7402 check_function_arguments (TREE_TYPE (fn), nargs, argarray);
7404 /* Avoid actually calling copy constructors and copy assignment operators,
7407 if (! flag_elide_constructors)
7408 /* Do things the hard way. */;
7409 else if (cand->num_convs == 1
7410 && (DECL_COPY_CONSTRUCTOR_P (fn)
7411 || DECL_MOVE_CONSTRUCTOR_P (fn))
7412 /* It's unsafe to elide the constructor when handling
7413 a noexcept-expression, it may evaluate to the wrong
7414 value (c++/53025). */
7415 && cp_noexcept_operand == 0)
7418 tree arg = argarray[num_artificial_parms_for (fn)];
7420 bool trivial = trivial_fn_p (fn);
7422 /* Pull out the real argument, disregarding const-correctness. */
7424 while (CONVERT_EXPR_P (targ)
7425 || TREE_CODE (targ) == NON_LVALUE_EXPR)
7426 targ = TREE_OPERAND (targ, 0);
7427 if (TREE_CODE (targ) == ADDR_EXPR)
7429 targ = TREE_OPERAND (targ, 0);
7430 if (!same_type_ignoring_top_level_qualifiers_p
7431 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
7440 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
7442 /* [class.copy]: the copy constructor is implicitly defined even if
7443 the implementation elided its use. */
7444 if (!trivial || DECL_DELETED_FN (fn))
7446 if (!mark_used (fn, complain) && !(complain & tf_error))
7447 return error_mark_node;
7448 already_used = true;
7451 /* If we're creating a temp and we already have one, don't create a
7452 new one. If we're not creating a temp but we get one, use
7453 INIT_EXPR to collapse the temp into our target. Otherwise, if the
7454 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
7455 temp or an INIT_EXPR otherwise. */
7457 if (is_dummy_object (fa))
7459 if (TREE_CODE (arg) == TARGET_EXPR)
7462 return force_target_expr (DECL_CONTEXT (fn), arg, complain);
7465 || (TREE_CODE (arg) == TARGET_EXPR
7466 && !unsafe_copy_elision_p (fa, arg)))
7468 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL,
7471 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
7475 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
7476 && trivial_fn_p (fn)
7477 && !DECL_DELETED_FN (fn))
7479 tree to = stabilize_reference
7480 (cp_build_indirect_ref (argarray[0], RO_NULL, complain));
7481 tree type = TREE_TYPE (to);
7482 tree as_base = CLASSTYPE_AS_BASE (type);
7483 tree arg = argarray[1];
7485 if (is_really_empty_class (type))
7487 /* Avoid copying empty classes. */
7488 val = build2 (COMPOUND_EXPR, void_type_node, to, arg);
7489 TREE_NO_WARNING (val) = 1;
7490 val = build2 (COMPOUND_EXPR, type, val, to);
7491 TREE_NO_WARNING (val) = 1;
7493 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
7495 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
7496 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
7500 /* We must only copy the non-tail padding parts. */
7502 tree array_type, alias_set;
7504 arg2 = TYPE_SIZE_UNIT (as_base);
7505 arg0 = cp_build_addr_expr (to, complain);
7507 array_type = build_array_type (char_type_node,
7509 (size_binop (MINUS_EXPR,
7510 arg2, size_int (1))));
7511 alias_set = build_int_cst (build_pointer_type (type), 0);
7512 t = build2 (MODIFY_EXPR, void_type_node,
7513 build2 (MEM_REF, array_type, arg0, alias_set),
7514 build2 (MEM_REF, array_type, arg, alias_set));
7515 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to);
7516 TREE_NO_WARNING (val) = 1;
7521 else if (DECL_DESTRUCTOR_P (fn)
7522 && trivial_fn_p (fn)
7523 && !DECL_DELETED_FN (fn))
7524 return fold_convert (void_type_node, argarray[0]);
7525 /* FIXME handle trivial default constructor, too. */
7527 /* For calls to a multi-versioned function, overload resolution
7528 returns the function with the highest target priority, that is,
7529 the version that will checked for dispatching first. If this
7530 version is inlinable, a direct call to this version can be made
7531 otherwise the call should go through the dispatcher. */
7533 if (DECL_FUNCTION_VERSIONED (fn)
7534 && (current_function_decl == NULL
7535 || !targetm.target_option.can_inline_p (current_function_decl, fn)))
7537 fn = get_function_version_dispatcher (fn);
7541 mark_versions_used (fn);
7545 && !mark_used (fn, complain))
7546 return error_mark_node;
7548 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0
7549 /* Don't mess with virtual lookup in instantiate_non_dependent_expr;
7550 virtual functions can't be constexpr. */
7551 && !in_template_function ())
7554 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
7556 ba_any, NULL, complain);
7557 gcc_assert (binfo && binfo != error_mark_node);
7559 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1,
7561 if (TREE_SIDE_EFFECTS (argarray[0]))
7562 argarray[0] = save_expr (argarray[0]);
7563 t = build_pointer_type (TREE_TYPE (fn));
7564 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
7565 fn = build_java_interface_fn_ref (fn, argarray[0]);
7567 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
7572 fn = build_addr_func (fn, complain);
7573 if (fn == error_mark_node)
7574 return error_mark_node;
7577 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag);
7578 if (TREE_CODE (call) == CALL_EXPR
7579 && (cand->flags & LOOKUP_LIST_INIT_CTOR))
7580 CALL_EXPR_LIST_INIT_P (call) = true;
7584 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
7585 This function performs no overload resolution, conversion, or other
7586 high-level operations. */
7589 build_cxx_call (tree fn, int nargs, tree *argarray,
7590 tsubst_flags_t complain)
7595 /* Remember roughly where this call is. */
7596 location_t loc = EXPR_LOC_OR_LOC (fn, input_location);
7597 fn = build_call_a (fn, nargs, argarray);
7598 SET_EXPR_LOCATION (fn, loc);
7600 fndecl = get_callee_fndecl (fn);
7602 /* Check that arguments to builtin functions match the expectations. */
7604 && DECL_BUILT_IN (fndecl)
7605 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
7606 && !check_builtin_function_arguments (fndecl, nargs, argarray))
7607 return error_mark_node;
7609 /* If it is a built-in array notation function, then the return type of
7610 the function is the element type of the array passed in as array
7611 notation (i.e. the first parameter of the function). */
7612 if (flag_cilkplus && TREE_CODE (fn) == CALL_EXPR)
7614 enum built_in_function bif =
7615 is_cilkplus_reduce_builtin (CALL_EXPR_FN (fn));
7616 if (bif == BUILT_IN_CILKPLUS_SEC_REDUCE_ADD
7617 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MUL
7618 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MAX
7619 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MIN
7620 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE
7621 || bif == BUILT_IN_CILKPLUS_SEC_REDUCE_MUTATING)
7623 if (call_expr_nargs (fn) == 0)
7625 error_at (EXPR_LOCATION (fn), "Invalid builtin arguments");
7626 return error_mark_node;
7628 /* for bif == BUILT_IN_CILKPLUS_SEC_REDUCE_ALL_ZERO or
7629 BUILT_IN_CILKPLUS_SEC_REDUCE_ANY_ZERO or
7630 BUILT_IN_CILKPLUS_SEC_REDUCE_ANY_NONZERO or
7631 BUILT_IN_CILKPLUS_SEC_REDUCE_ALL_NONZERO or
7632 BUILT_IN_CILKPLUS_SEC_REDUCE_MIN_IND or
7633 BUILT_IN_CILKPLUS_SEC_REDUCE_MAX_IND
7634 The pre-defined return-type is the correct one. */
7635 tree array_ntn = CALL_EXPR_ARG (fn, 0);
7636 TREE_TYPE (fn) = TREE_TYPE (array_ntn);
7641 /* Some built-in function calls will be evaluated at compile-time in
7642 fold (). Set optimize to 1 when folding __builtin_constant_p inside
7643 a constexpr function so that fold_builtin_1 doesn't fold it to 0. */
7644 optimize_sav = optimize;
7645 if (!optimize && fndecl && DECL_IS_BUILTIN_CONSTANT_P (fndecl)
7646 && current_function_decl
7647 && DECL_DECLARED_CONSTEXPR_P (current_function_decl))
7649 fn = fold_if_not_in_template (fn);
7650 optimize = optimize_sav;
7652 if (VOID_TYPE_P (TREE_TYPE (fn)))
7655 /* 5.2.2/11: If a function call is a prvalue of object type: if the
7656 function call is either the operand of a decltype-specifier or the
7657 right operand of a comma operator that is the operand of a
7658 decltype-specifier, a temporary object is not introduced for the
7659 prvalue. The type of the prvalue may be incomplete. */
7660 if (!(complain & tf_decltype))
7662 fn = require_complete_type_sfinae (fn, complain);
7663 if (fn == error_mark_node)
7664 return error_mark_node;
7666 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
7667 fn = build_cplus_new (TREE_TYPE (fn), fn, complain);
7669 return convert_from_reference (fn);
7672 static GTY(()) tree java_iface_lookup_fn;
7674 /* Make an expression which yields the address of the Java interface
7675 method FN. This is achieved by generating a call to libjava's
7676 _Jv_LookupInterfaceMethodIdx(). */
7679 build_java_interface_fn_ref (tree fn, tree instance)
7681 tree lookup_fn, method, idx;
7682 tree klass_ref, iface, iface_ref;
7685 if (!java_iface_lookup_fn)
7687 tree ftype = build_function_type_list (ptr_type_node,
7688 ptr_type_node, ptr_type_node,
7689 java_int_type_node, NULL_TREE);
7690 java_iface_lookup_fn
7691 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype,
7692 0, NOT_BUILT_IN, NULL, NULL_TREE);
7695 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
7696 This is the first entry in the vtable. */
7697 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL,
7698 tf_warning_or_error),
7701 /* Get the java.lang.Class pointer for the interface being called. */
7702 iface = DECL_CONTEXT (fn);
7703 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
7704 if (!iface_ref || !VAR_P (iface_ref)
7705 || DECL_CONTEXT (iface_ref) != iface)
7707 error ("could not find class$ field in java interface type %qT",
7709 return error_mark_node;
7711 iface_ref = build_address (iface_ref);
7712 iface_ref = convert (build_pointer_type (iface), iface_ref);
7714 /* Determine the itable index of FN. */
7716 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method))
7718 if (!DECL_VIRTUAL_P (method))
7724 idx = build_int_cst (NULL_TREE, i);
7726 lookup_fn = build1 (ADDR_EXPR,
7727 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
7728 java_iface_lookup_fn);
7729 return build_call_nary (ptr_type_node, lookup_fn,
7730 3, klass_ref, iface_ref, idx);
7733 /* Returns the value to use for the in-charge parameter when making a
7734 call to a function with the indicated NAME.
7736 FIXME:Can't we find a neater way to do this mapping? */
7739 in_charge_arg_for_name (tree name)
7741 if (name == base_ctor_identifier
7742 || name == base_dtor_identifier)
7743 return integer_zero_node;
7744 else if (name == complete_ctor_identifier)
7745 return integer_one_node;
7746 else if (name == complete_dtor_identifier)
7747 return integer_two_node;
7748 else if (name == deleting_dtor_identifier)
7749 return integer_three_node;
7751 /* This function should only be called with one of the names listed
7757 /* Build a call to a constructor, destructor, or an assignment
7758 operator for INSTANCE, an expression with class type. NAME
7759 indicates the special member function to call; *ARGS are the
7760 arguments. ARGS may be NULL. This may change ARGS. BINFO
7761 indicates the base of INSTANCE that is to be passed as the `this'
7762 parameter to the member function called.
7764 FLAGS are the LOOKUP_* flags to use when processing the call.
7766 If NAME indicates a complete object constructor, INSTANCE may be
7767 NULL_TREE. In this case, the caller will call build_cplus_new to
7768 store the newly constructed object into a VAR_DECL. */
7771 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args,
7772 tree binfo, int flags, tsubst_flags_t complain)
7775 /* The type of the subobject to be constructed or destroyed. */
7777 vec<tree, va_gc> *allocated = NULL;
7780 gcc_assert (name == complete_ctor_identifier
7781 || name == base_ctor_identifier
7782 || name == complete_dtor_identifier
7783 || name == base_dtor_identifier
7784 || name == deleting_dtor_identifier
7785 || name == ansi_assopname (NOP_EXPR));
7788 /* Resolve the name. */
7789 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
7790 return error_mark_node;
7792 binfo = TYPE_BINFO (binfo);
7795 gcc_assert (binfo != NULL_TREE);
7797 class_type = BINFO_TYPE (binfo);
7799 /* Handle the special case where INSTANCE is NULL_TREE. */
7800 if (name == complete_ctor_identifier && !instance)
7801 instance = build_dummy_object (class_type);
7804 if (name == complete_dtor_identifier
7805 || name == base_dtor_identifier
7806 || name == deleting_dtor_identifier)
7807 gcc_assert (args == NULL || vec_safe_is_empty (*args));
7809 /* Convert to the base class, if necessary. */
7810 if (!same_type_ignoring_top_level_qualifiers_p
7811 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
7813 if (name != ansi_assopname (NOP_EXPR))
7814 /* For constructors and destructors, either the base is
7815 non-virtual, or it is virtual but we are doing the
7816 conversion from a constructor or destructor for the
7817 complete object. In either case, we can convert
7819 instance = convert_to_base_statically (instance, binfo);
7821 /* However, for assignment operators, we must convert
7822 dynamically if the base is virtual. */
7823 instance = build_base_path (PLUS_EXPR, instance,
7824 binfo, /*nonnull=*/1, complain);
7828 gcc_assert (instance != NULL_TREE);
7830 fns = lookup_fnfields (binfo, name, 1);
7832 /* When making a call to a constructor or destructor for a subobject
7833 that uses virtual base classes, pass down a pointer to a VTT for
7835 if ((name == base_ctor_identifier
7836 || name == base_dtor_identifier)
7837 && CLASSTYPE_VBASECLASSES (class_type))
7842 /* If the current function is a complete object constructor
7843 or destructor, then we fetch the VTT directly.
7844 Otherwise, we look it up using the VTT we were given. */
7845 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
7846 vtt = decay_conversion (vtt, complain);
7847 if (vtt == error_mark_node)
7848 return error_mark_node;
7849 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
7850 build2 (EQ_EXPR, boolean_type_node,
7851 current_in_charge_parm, integer_zero_node),
7854 if (BINFO_SUBVTT_INDEX (binfo))
7855 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo));
7861 allocated = make_tree_vector ();
7865 vec_safe_insert (*args, 0, sub_vtt);
7868 ret = build_new_method_call (instance, fns, args,
7869 TYPE_BINFO (BINFO_TYPE (binfo)),
7873 if (allocated != NULL)
7874 release_tree_vector (allocated);
7876 if ((complain & tf_error)
7877 && (flags & LOOKUP_DELEGATING_CONS)
7878 && name == complete_ctor_identifier
7879 && TREE_CODE (ret) == CALL_EXPR
7880 && (DECL_ABSTRACT_ORIGIN (TREE_OPERAND (CALL_EXPR_FN (ret), 0))
7881 == current_function_decl))
7882 error ("constructor delegates to itself");
7887 /* Return the NAME, as a C string. The NAME indicates a function that
7888 is a member of TYPE. *FREE_P is set to true if the caller must
7889 free the memory returned.
7891 Rather than go through all of this, we should simply set the names
7892 of constructors and destructors appropriately, and dispense with
7893 ctor_identifier, dtor_identifier, etc. */
7896 name_as_c_string (tree name, tree type, bool *free_p)
7900 /* Assume that we will not allocate memory. */
7902 /* Constructors and destructors are special. */
7903 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
7906 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))));
7907 /* For a destructor, add the '~'. */
7908 if (name == complete_dtor_identifier
7909 || name == base_dtor_identifier
7910 || name == deleting_dtor_identifier)
7912 pretty_name = concat ("~", pretty_name, NULL);
7913 /* Remember that we need to free the memory allocated. */
7917 else if (IDENTIFIER_TYPENAME_P (name))
7919 pretty_name = concat ("operator ",
7920 type_as_string_translate (TREE_TYPE (name),
7921 TFF_PLAIN_IDENTIFIER),
7923 /* Remember that we need to free the memory allocated. */
7927 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name)));
7932 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
7933 be set, upon return, to the function called. ARGS may be NULL.
7934 This may change ARGS. */
7937 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args,
7938 tree conversion_path, int flags,
7939 tree *fn_p, tsubst_flags_t complain)
7941 struct z_candidate *candidates = 0, *cand;
7942 tree explicit_targs = NULL_TREE;
7943 tree basetype = NULL_TREE;
7944 tree access_binfo, binfo;
7946 tree first_mem_arg = NULL_TREE;
7948 bool skip_first_for_error;
7949 vec<tree, va_gc> *user_args;
7952 int template_only = 0;
7956 vec<tree, va_gc> *orig_args = NULL;
7959 gcc_assert (instance != NULL_TREE);
7961 /* We don't know what function we're going to call, yet. */
7965 if (error_operand_p (instance)
7966 || !fns || error_operand_p (fns))
7967 return error_mark_node;
7969 if (!BASELINK_P (fns))
7971 if (complain & tf_error)
7972 error ("call to non-function %qD", fns);
7973 return error_mark_node;
7976 orig_instance = instance;
7979 /* Dismantle the baselink to collect all the information we need. */
7980 if (!conversion_path)
7981 conversion_path = BASELINK_BINFO (fns);
7982 access_binfo = BASELINK_ACCESS_BINFO (fns);
7983 binfo = BASELINK_BINFO (fns);
7984 optype = BASELINK_OPTYPE (fns);
7985 fns = BASELINK_FUNCTIONS (fns);
7986 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
7988 explicit_targs = TREE_OPERAND (fns, 1);
7989 fns = TREE_OPERAND (fns, 0);
7992 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
7993 || TREE_CODE (fns) == TEMPLATE_DECL
7994 || TREE_CODE (fns) == OVERLOAD);
7995 fn = get_first_fn (fns);
7996 name = DECL_NAME (fn);
7998 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
7999 gcc_assert (CLASS_TYPE_P (basetype));
8001 if (processing_template_decl)
8003 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
8004 instance = build_non_dependent_expr (instance);
8006 make_args_non_dependent (*args);
8009 user_args = args == NULL ? NULL : *args;
8010 /* Under DR 147 A::A() is an invalid constructor call,
8011 not a functional cast. */
8012 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
8014 if (! (complain & tf_error))
8015 return error_mark_node;
8017 if (permerror (input_location,
8018 "cannot call constructor %<%T::%D%> directly",
8020 inform (input_location, "for a function-style cast, remove the "
8021 "redundant %<::%D%>", name);
8022 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
8027 /* Figure out whether to skip the first argument for the error
8028 message we will display to users if an error occurs. We don't
8029 want to display any compiler-generated arguments. The "this"
8030 pointer hasn't been added yet. However, we must remove the VTT
8031 pointer if this is a call to a base-class constructor or
8033 skip_first_for_error = false;
8034 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
8036 /* Callers should explicitly indicate whether they want to construct
8037 the complete object or just the part without virtual bases. */
8038 gcc_assert (name != ctor_identifier);
8039 /* Similarly for destructors. */
8040 gcc_assert (name != dtor_identifier);
8041 /* Remove the VTT pointer, if present. */
8042 if ((name == base_ctor_identifier || name == base_dtor_identifier)
8043 && CLASSTYPE_VBASECLASSES (basetype))
8044 skip_first_for_error = true;
8047 /* Process the argument list. */
8048 if (args != NULL && *args != NULL)
8050 *args = resolve_args (*args, complain);
8052 return error_mark_node;
8055 /* Consider the object argument to be used even if we end up selecting a
8056 static member function. */
8057 instance = mark_type_use (instance);
8059 /* It's OK to call destructors and constructors on cv-qualified objects.
8060 Therefore, convert the INSTANCE to the unqualified type, if
8062 if (DECL_DESTRUCTOR_P (fn)
8063 || DECL_CONSTRUCTOR_P (fn))
8065 if (!same_type_p (basetype, TREE_TYPE (instance)))
8067 instance = build_this (instance);
8068 instance = build_nop (build_pointer_type (basetype), instance);
8069 instance = build_fold_indirect_ref (instance);
8072 if (DECL_DESTRUCTOR_P (fn))
8073 name = complete_dtor_identifier;
8075 /* For the overload resolution we need to find the actual `this`
8076 that would be captured if the call turns out to be to a
8077 non-static member function. Do not actually capture it at this
8079 if (DECL_CONSTRUCTOR_P (fn))
8080 /* Constructors don't use the enclosing 'this'. */
8081 first_mem_arg = instance;
8083 first_mem_arg = maybe_resolve_dummy (instance, false);
8085 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8086 p = conversion_obstack_alloc (0);
8088 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
8089 initializer, not T({ }). */
8090 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !vec_safe_is_empty (*args)
8091 && DIRECT_LIST_INIT_P ((**args)[0]))
8093 tree init_list = (**args)[0];
8094 tree init = NULL_TREE;
8096 gcc_assert ((*args)->length () == 1
8097 && !(flags & LOOKUP_ONLYCONVERTING));
8099 /* If the initializer list has no elements and T is a class type with
8100 a default constructor, the object is value-initialized. Handle
8101 this here so we don't need to handle it wherever we use
8102 build_special_member_call. */
8103 if (CONSTRUCTOR_NELTS (init_list) == 0
8104 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
8105 /* For a user-provided default constructor, use the normal
8106 mechanisms so that protected access works. */
8107 && type_has_non_user_provided_default_constructor (basetype)
8108 && !processing_template_decl)
8109 init = build_value_init (basetype, complain);
8111 /* If BASETYPE is an aggregate, we need to do aggregate
8113 else if (CP_AGGREGATE_TYPE_P (basetype))
8114 init = digest_init (basetype, init_list, complain);
8118 if (is_dummy_object (instance))
8119 return get_target_expr_sfinae (init, complain);
8120 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init);
8121 TREE_SIDE_EFFECTS (init) = true;
8125 /* Otherwise go ahead with overload resolution. */
8126 add_list_candidates (fns, first_mem_arg, init_list,
8127 basetype, explicit_targs, template_only,
8128 conversion_path, access_binfo, flags,
8129 &candidates, complain);
8133 add_candidates (fns, first_mem_arg, user_args, optype,
8134 explicit_targs, template_only, conversion_path,
8135 access_binfo, flags, &candidates, complain);
8137 any_viable_p = false;
8138 candidates = splice_viable (candidates, false, &any_viable_p);
8142 if (complain & tf_error)
8144 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
8145 cxx_incomplete_type_error (instance, basetype);
8147 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
8148 basetype, optype, build_tree_list_vec (user_args),
8149 TREE_TYPE (instance));
8156 pretty_name = name_as_c_string (name, basetype, &free_p);
8157 arglist = build_tree_list_vec (user_args);
8158 if (skip_first_for_error)
8159 arglist = TREE_CHAIN (arglist);
8160 error ("no matching function for call to %<%T::%s(%A)%#V%>",
8161 basetype, pretty_name, arglist,
8162 TREE_TYPE (instance));
8166 print_z_candidates (location_of (name), candidates);
8168 call = error_mark_node;
8172 cand = tourney (candidates, complain);
8179 if (complain & tf_error)
8181 pretty_name = name_as_c_string (name, basetype, &free_p);
8182 arglist = build_tree_list_vec (user_args);
8183 if (skip_first_for_error)
8184 arglist = TREE_CHAIN (arglist);
8185 if (!any_strictly_viable (candidates))
8186 error ("no matching function for call to %<%s(%A)%>",
8187 pretty_name, arglist);
8189 error ("call of overloaded %<%s(%A)%> is ambiguous",
8190 pretty_name, arglist);
8191 print_z_candidates (location_of (name), candidates);
8195 call = error_mark_node;
8202 if (!(flags & LOOKUP_NONVIRTUAL)
8203 && DECL_PURE_VIRTUAL_P (fn)
8204 && instance == current_class_ref
8205 && (complain & tf_warning))
8207 /* This is not an error, it is runtime undefined
8209 if (!current_function_decl)
8210 warning (0, "pure virtual %q#D called from "
8211 "non-static data member initializer", fn);
8212 else if (DECL_CONSTRUCTOR_P (current_function_decl)
8213 || DECL_DESTRUCTOR_P (current_function_decl))
8214 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl)
8215 ? "pure virtual %q#D called from constructor"
8216 : "pure virtual %q#D called from destructor"),
8220 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
8221 && !DECL_CONSTRUCTOR_P (fn)
8222 && is_dummy_object (instance))
8224 instance = maybe_resolve_dummy (instance, true);
8225 if (instance == error_mark_node)
8226 call = error_mark_node;
8227 else if (!is_dummy_object (instance))
8229 /* We captured 'this' in the current lambda now that
8230 we know we really need it. */
8231 cand->first_arg = instance;
8235 if (complain & tf_error)
8236 error ("cannot call member function %qD without object",
8238 call = error_mark_node;
8242 if (call != error_mark_node)
8244 /* Optimize away vtable lookup if we know that this
8245 function can't be overridden. We need to check if
8246 the context and the type where we found fn are the same,
8247 actually FN might be defined in a different class
8248 type because of a using-declaration. In this case, we
8249 do not want to perform a non-virtual call. */
8250 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
8251 && same_type_ignoring_top_level_qualifiers_p
8252 (DECL_CONTEXT (fn), BINFO_TYPE (binfo))
8253 && resolves_to_fixed_type_p (instance, 0))
8254 flags |= LOOKUP_NONVIRTUAL;
8256 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
8257 /* Now we know what function is being called. */
8260 /* Build the actual CALL_EXPR. */
8261 call = build_over_call (cand, flags, complain);
8262 /* In an expression of the form `a->f()' where `f' turns
8263 out to be a static member function, `a' is
8264 none-the-less evaluated. */
8265 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
8266 && !is_dummy_object (instance)
8267 && TREE_SIDE_EFFECTS (instance))
8268 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
8270 else if (call != error_mark_node
8271 && DECL_DESTRUCTOR_P (cand->fn)
8272 && !VOID_TYPE_P (TREE_TYPE (call)))
8273 /* An explicit call of the form "x->~X()" has type
8274 "void". However, on platforms where destructors
8275 return "this" (i.e., those where
8276 targetm.cxx.cdtor_returns_this is true), such calls
8277 will appear to have a return value of pointer type
8278 to the low-level call machinery. We do not want to
8279 change the low-level machinery, since we want to be
8280 able to optimize "delete f()" on such platforms as
8281 "operator delete(~X(f()))" (rather than generating
8282 "t = f(), ~X(t), operator delete (t)"). */
8283 call = build_nop (void_type_node, call);
8288 if (processing_template_decl && call != error_mark_node)
8290 bool cast_to_void = false;
8292 if (TREE_CODE (call) == COMPOUND_EXPR)
8293 call = TREE_OPERAND (call, 1);
8294 else if (TREE_CODE (call) == NOP_EXPR)
8296 cast_to_void = true;
8297 call = TREE_OPERAND (call, 0);
8299 if (INDIRECT_REF_P (call))
8300 call = TREE_OPERAND (call, 0);
8301 call = (build_min_non_dep_call_vec
8303 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
8304 orig_instance, orig_fns, NULL_TREE),
8306 SET_EXPR_LOCATION (call, input_location);
8307 call = convert_from_reference (call);
8309 call = build_nop (void_type_node, call);
8312 /* Free all the conversions we allocated. */
8313 obstack_free (&conversion_obstack, p);
8315 if (orig_args != NULL)
8316 release_tree_vector (orig_args);
8321 /* Wrapper for above. */
8324 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args,
8325 tree conversion_path, int flags,
8326 tree *fn_p, tsubst_flags_t complain)
8329 bool subtime = timevar_cond_start (TV_OVERLOAD);
8330 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags,
8332 timevar_cond_stop (TV_OVERLOAD, subtime);
8336 /* Returns true iff standard conversion sequence ICS1 is a proper
8337 subsequence of ICS2. */
8340 is_subseq (conversion *ics1, conversion *ics2)
8342 /* We can assume that a conversion of the same code
8343 between the same types indicates a subsequence since we only get
8344 here if the types we are converting from are the same. */
8346 while (ics1->kind == ck_rvalue
8347 || ics1->kind == ck_lvalue)
8348 ics1 = next_conversion (ics1);
8352 while (ics2->kind == ck_rvalue
8353 || ics2->kind == ck_lvalue)
8354 ics2 = next_conversion (ics2);
8356 if (ics2->kind == ck_user
8357 || ics2->kind == ck_ambig
8358 || ics2->kind == ck_aggr
8359 || ics2->kind == ck_list
8360 || ics2->kind == ck_identity)
8361 /* At this point, ICS1 cannot be a proper subsequence of
8362 ICS2. We can get a USER_CONV when we are comparing the
8363 second standard conversion sequence of two user conversion
8367 ics2 = next_conversion (ics2);
8369 if (ics2->kind == ics1->kind
8370 && same_type_p (ics2->type, ics1->type)
8371 && same_type_p (next_conversion (ics2)->type,
8372 next_conversion (ics1)->type))
8377 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
8378 be any _TYPE nodes. */
8381 is_properly_derived_from (tree derived, tree base)
8383 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
8386 /* We only allow proper derivation here. The DERIVED_FROM_P macro
8387 considers every class derived from itself. */
8388 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
8389 && DERIVED_FROM_P (base, derived));
8392 /* We build the ICS for an implicit object parameter as a pointer
8393 conversion sequence. However, such a sequence should be compared
8394 as if it were a reference conversion sequence. If ICS is the
8395 implicit conversion sequence for an implicit object parameter,
8396 modify it accordingly. */
8399 maybe_handle_implicit_object (conversion **ics)
8403 /* [over.match.funcs]
8405 For non-static member functions, the type of the
8406 implicit object parameter is "reference to cv X"
8407 where X is the class of which the function is a
8408 member and cv is the cv-qualification on the member
8409 function declaration. */
8410 conversion *t = *ics;
8411 tree reference_type;
8413 /* The `this' parameter is a pointer to a class type. Make the
8414 implicit conversion talk about a reference to that same class
8416 reference_type = TREE_TYPE (t->type);
8417 reference_type = build_reference_type (reference_type);
8419 if (t->kind == ck_qual)
8420 t = next_conversion (t);
8421 if (t->kind == ck_ptr)
8422 t = next_conversion (t);
8423 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
8424 t = direct_reference_binding (reference_type, t);
8426 t->rvaluedness_matches_p = 0;
8431 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
8432 and return the initial reference binding conversion. Otherwise,
8433 leave *ICS unchanged and return NULL. */
8436 maybe_handle_ref_bind (conversion **ics)
8438 if ((*ics)->kind == ck_ref_bind)
8440 conversion *old_ics = *ics;
8441 *ics = next_conversion (old_ics);
8442 (*ics)->user_conv_p = old_ics->user_conv_p;
8449 /* Compare two implicit conversion sequences according to the rules set out in
8450 [over.ics.rank]. Return values:
8452 1: ics1 is better than ics2
8453 -1: ics2 is better than ics1
8454 0: ics1 and ics2 are indistinguishable */
8457 compare_ics (conversion *ics1, conversion *ics2)
8463 tree deref_from_type1 = NULL_TREE;
8464 tree deref_from_type2 = NULL_TREE;
8465 tree deref_to_type1 = NULL_TREE;
8466 tree deref_to_type2 = NULL_TREE;
8467 conversion_rank rank1, rank2;
8469 /* REF_BINDING is nonzero if the result of the conversion sequence
8470 is a reference type. In that case REF_CONV is the reference
8471 binding conversion. */
8472 conversion *ref_conv1;
8473 conversion *ref_conv2;
8475 /* Compare badness before stripping the reference conversion. */
8476 if (ics1->bad_p > ics2->bad_p)
8478 else if (ics1->bad_p < ics2->bad_p)
8481 /* Handle implicit object parameters. */
8482 maybe_handle_implicit_object (&ics1);
8483 maybe_handle_implicit_object (&ics2);
8485 /* Handle reference parameters. */
8486 ref_conv1 = maybe_handle_ref_bind (&ics1);
8487 ref_conv2 = maybe_handle_ref_bind (&ics2);
8489 /* List-initialization sequence L1 is a better conversion sequence than
8490 list-initialization sequence L2 if L1 converts to
8491 std::initializer_list<X> for some X and L2 does not. */
8492 if (ics1->kind == ck_list && ics2->kind != ck_list)
8494 if (ics2->kind == ck_list && ics1->kind != ck_list)
8499 When comparing the basic forms of implicit conversion sequences (as
8500 defined in _over.best.ics_)
8502 --a standard conversion sequence (_over.ics.scs_) is a better
8503 conversion sequence than a user-defined conversion sequence
8504 or an ellipsis conversion sequence, and
8506 --a user-defined conversion sequence (_over.ics.user_) is a
8507 better conversion sequence than an ellipsis conversion sequence
8508 (_over.ics.ellipsis_). */
8509 /* Use BAD_CONVERSION_RANK because we already checked for a badness
8510 mismatch. If both ICS are bad, we try to make a decision based on
8511 what would have happened if they'd been good. This is not an
8512 extension, we'll still give an error when we build up the call; this
8513 just helps us give a more helpful error message. */
8514 rank1 = BAD_CONVERSION_RANK (ics1);
8515 rank2 = BAD_CONVERSION_RANK (ics2);
8519 else if (rank1 < rank2)
8522 if (ics1->ellipsis_p)
8523 /* Both conversions are ellipsis conversions. */
8526 /* User-defined conversion sequence U1 is a better conversion sequence
8527 than another user-defined conversion sequence U2 if they contain the
8528 same user-defined conversion operator or constructor and if the sec-
8529 ond standard conversion sequence of U1 is better than the second
8530 standard conversion sequence of U2. */
8532 /* Handle list-conversion with the same code even though it isn't always
8533 ranked as a user-defined conversion and it doesn't have a second
8534 standard conversion sequence; it will still have the desired effect.
8535 Specifically, we need to do the reference binding comparison at the
8536 end of this function. */
8538 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr)
8543 for (t1 = ics1; t1->kind != ck_user; t1 = next_conversion (t1))
8544 if (t1->kind == ck_ambig || t1->kind == ck_aggr
8545 || t1->kind == ck_list)
8547 for (t2 = ics2; t2->kind != ck_user; t2 = next_conversion (t2))
8548 if (t2->kind == ck_ambig || t2->kind == ck_aggr
8549 || t2->kind == ck_list)
8552 if (t1->kind != t2->kind)
8554 else if (t1->kind == ck_user)
8556 if (t1->cand->fn != t2->cand->fn)
8561 /* For ambiguous or aggregate conversions, use the target type as
8562 a proxy for the conversion function. */
8563 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
8567 /* We can just fall through here, after setting up
8568 FROM_TYPE1 and FROM_TYPE2. */
8569 from_type1 = t1->type;
8570 from_type2 = t2->type;
8577 /* We're dealing with two standard conversion sequences.
8581 Standard conversion sequence S1 is a better conversion
8582 sequence than standard conversion sequence S2 if
8584 --S1 is a proper subsequence of S2 (comparing the conversion
8585 sequences in the canonical form defined by _over.ics.scs_,
8586 excluding any Lvalue Transformation; the identity
8587 conversion sequence is considered to be a subsequence of
8588 any non-identity conversion sequence */
8591 while (t1->kind != ck_identity)
8592 t1 = next_conversion (t1);
8593 from_type1 = t1->type;
8596 while (t2->kind != ck_identity)
8597 t2 = next_conversion (t2);
8598 from_type2 = t2->type;
8601 /* One sequence can only be a subsequence of the other if they start with
8602 the same type. They can start with different types when comparing the
8603 second standard conversion sequence in two user-defined conversion
8605 if (same_type_p (from_type1, from_type2))
8607 if (is_subseq (ics1, ics2))
8609 if (is_subseq (ics2, ics1))
8617 --the rank of S1 is better than the rank of S2 (by the rules
8620 Standard conversion sequences are ordered by their ranks: an Exact
8621 Match is a better conversion than a Promotion, which is a better
8622 conversion than a Conversion.
8624 Two conversion sequences with the same rank are indistinguishable
8625 unless one of the following rules applies:
8627 --A conversion that does not a convert a pointer, pointer to member,
8628 or std::nullptr_t to bool is better than one that does.
8630 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
8631 so that we do not have to check it explicitly. */
8632 if (ics1->rank < ics2->rank)
8634 else if (ics2->rank < ics1->rank)
8637 to_type1 = ics1->type;
8638 to_type2 = ics2->type;
8640 /* A conversion from scalar arithmetic type to complex is worse than a
8641 conversion between scalar arithmetic types. */
8642 if (same_type_p (from_type1, from_type2)
8643 && ARITHMETIC_TYPE_P (from_type1)
8644 && ARITHMETIC_TYPE_P (to_type1)
8645 && ARITHMETIC_TYPE_P (to_type2)
8646 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
8647 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
8649 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
8655 if (TYPE_PTR_P (from_type1)
8656 && TYPE_PTR_P (from_type2)
8657 && TYPE_PTR_P (to_type1)
8658 && TYPE_PTR_P (to_type2))
8660 deref_from_type1 = TREE_TYPE (from_type1);
8661 deref_from_type2 = TREE_TYPE (from_type2);
8662 deref_to_type1 = TREE_TYPE (to_type1);
8663 deref_to_type2 = TREE_TYPE (to_type2);
8665 /* The rules for pointers to members A::* are just like the rules
8666 for pointers A*, except opposite: if B is derived from A then
8667 A::* converts to B::*, not vice versa. For that reason, we
8668 switch the from_ and to_ variables here. */
8669 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2)
8670 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2))
8671 || (TYPE_PTRMEMFUNC_P (from_type1)
8672 && TYPE_PTRMEMFUNC_P (from_type2)
8673 && TYPE_PTRMEMFUNC_P (to_type1)
8674 && TYPE_PTRMEMFUNC_P (to_type2)))
8676 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
8677 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
8678 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
8679 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
8682 if (deref_from_type1 != NULL_TREE
8683 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
8684 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
8686 /* This was one of the pointer or pointer-like conversions.
8690 --If class B is derived directly or indirectly from class A,
8691 conversion of B* to A* is better than conversion of B* to
8692 void*, and conversion of A* to void* is better than
8693 conversion of B* to void*. */
8694 if (VOID_TYPE_P (deref_to_type1)
8695 && VOID_TYPE_P (deref_to_type2))
8697 if (is_properly_derived_from (deref_from_type1,
8700 else if (is_properly_derived_from (deref_from_type2,
8704 else if (VOID_TYPE_P (deref_to_type1)
8705 || VOID_TYPE_P (deref_to_type2))
8707 if (same_type_p (deref_from_type1, deref_from_type2))
8709 if (VOID_TYPE_P (deref_to_type2))
8711 if (is_properly_derived_from (deref_from_type1,
8715 /* We know that DEREF_TO_TYPE1 is `void' here. */
8716 else if (is_properly_derived_from (deref_from_type1,
8721 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
8722 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
8726 --If class B is derived directly or indirectly from class A
8727 and class C is derived directly or indirectly from B,
8729 --conversion of C* to B* is better than conversion of C* to
8732 --conversion of B* to A* is better than conversion of C* to
8734 if (same_type_p (deref_from_type1, deref_from_type2))
8736 if (is_properly_derived_from (deref_to_type1,
8739 else if (is_properly_derived_from (deref_to_type2,
8743 else if (same_type_p (deref_to_type1, deref_to_type2))
8745 if (is_properly_derived_from (deref_from_type2,
8748 else if (is_properly_derived_from (deref_from_type1,
8754 else if (CLASS_TYPE_P (non_reference (from_type1))
8755 && same_type_p (from_type1, from_type2))
8757 tree from = non_reference (from_type1);
8761 --binding of an expression of type C to a reference of type
8762 B& is better than binding an expression of type C to a
8763 reference of type A&
8765 --conversion of C to B is better than conversion of C to A, */
8766 if (is_properly_derived_from (from, to_type1)
8767 && is_properly_derived_from (from, to_type2))
8769 if (is_properly_derived_from (to_type1, to_type2))
8771 else if (is_properly_derived_from (to_type2, to_type1))
8775 else if (CLASS_TYPE_P (non_reference (to_type1))
8776 && same_type_p (to_type1, to_type2))
8778 tree to = non_reference (to_type1);
8782 --binding of an expression of type B to a reference of type
8783 A& is better than binding an expression of type C to a
8784 reference of type A&,
8786 --conversion of B to A is better than conversion of C to A */
8787 if (is_properly_derived_from (from_type1, to)
8788 && is_properly_derived_from (from_type2, to))
8790 if (is_properly_derived_from (from_type2, from_type1))
8792 else if (is_properly_derived_from (from_type1, from_type2))
8799 --S1 and S2 differ only in their qualification conversion and yield
8800 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
8801 qualification signature of type T1 is a proper subset of the cv-
8802 qualification signature of type T2 */
8803 if (ics1->kind == ck_qual
8804 && ics2->kind == ck_qual
8805 && same_type_p (from_type1, from_type2))
8807 int result = comp_cv_qual_signature (to_type1, to_type2);
8814 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
8815 to an implicit object parameter of a non-static member function
8816 declared without a ref-qualifier, and either S1 binds an lvalue
8817 reference to an lvalue and S2 binds an rvalue reference or S1 binds an
8818 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
8819 draft standard, 13.3.3.2)
8821 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
8822 types to which the references refer are the same type except for
8823 top-level cv-qualifiers, and the type to which the reference
8824 initialized by S2 refers is more cv-qualified than the type to
8825 which the reference initialized by S1 refers.
8827 DR 1328 [over.match.best]: the context is an initialization by
8828 conversion function for direct reference binding (13.3.1.6) of a
8829 reference to function type, the return type of F1 is the same kind of
8830 reference (i.e. lvalue or rvalue) as the reference being initialized,
8831 and the return type of F2 is not. */
8833 if (ref_conv1 && ref_conv2)
8835 if (!ref_conv1->this_p && !ref_conv2->this_p
8836 && (ref_conv1->rvaluedness_matches_p
8837 != ref_conv2->rvaluedness_matches_p)
8838 && (same_type_p (ref_conv1->type, ref_conv2->type)
8839 || (TYPE_REF_IS_RVALUE (ref_conv1->type)
8840 != TYPE_REF_IS_RVALUE (ref_conv2->type))))
8842 if (ref_conv1->bad_p
8843 && !same_type_p (TREE_TYPE (ref_conv1->type),
8844 TREE_TYPE (ref_conv2->type)))
8845 /* Don't prefer a bad conversion that drops cv-quals to a bad
8846 conversion with the wrong rvalueness. */
8848 return (ref_conv1->rvaluedness_matches_p
8849 - ref_conv2->rvaluedness_matches_p);
8852 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
8854 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type));
8855 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type));
8856 if (ref_conv1->bad_p)
8858 /* Prefer the one that drops fewer cv-quals. */
8859 tree ftype = next_conversion (ref_conv1)->type;
8860 int fquals = cp_type_quals (ftype);
8864 return comp_cv_qualification (q2, q1);
8868 /* Neither conversion sequence is better than the other. */
8872 /* The source type for this standard conversion sequence. */
8875 source_type (conversion *t)
8877 for (;; t = next_conversion (t))
8879 if (t->kind == ck_user
8880 || t->kind == ck_ambig
8881 || t->kind == ck_identity)
8887 /* Note a warning about preferring WINNER to LOSER. We do this by storing
8888 a pointer to LOSER and re-running joust to produce the warning if WINNER
8889 is actually used. */
8892 add_warning (struct z_candidate *winner, struct z_candidate *loser)
8894 candidate_warning *cw = (candidate_warning *)
8895 conversion_obstack_alloc (sizeof (candidate_warning));
8897 cw->next = winner->warnings;
8898 winner->warnings = cw;
8901 /* Compare two candidates for overloading as described in
8902 [over.match.best]. Return values:
8904 1: cand1 is better than cand2
8905 -1: cand2 is better than cand1
8906 0: cand1 and cand2 are indistinguishable */
8909 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn,
8910 tsubst_flags_t complain)
8913 int off1 = 0, off2 = 0;
8917 /* Candidates that involve bad conversions are always worse than those
8919 if (cand1->viable > cand2->viable)
8921 if (cand1->viable < cand2->viable)
8924 /* If we have two pseudo-candidates for conversions to the same type,
8925 or two candidates for the same function, arbitrarily pick one. */
8926 if (cand1->fn == cand2->fn
8927 && (IS_TYPE_OR_DECL_P (cand1->fn)))
8930 /* Prefer a non-deleted function over an implicitly deleted move
8931 constructor or assignment operator. This differs slightly from the
8932 wording for issue 1402 (which says the move op is ignored by overload
8933 resolution), but this way produces better error messages. */
8934 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
8935 && TREE_CODE (cand2->fn) == FUNCTION_DECL
8936 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn))
8938 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn)
8939 && move_fn_p (cand1->fn))
8941 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn)
8942 && move_fn_p (cand2->fn))
8946 /* a viable function F1
8947 is defined to be a better function than another viable function F2 if
8948 for all arguments i, ICSi(F1) is not a worse conversion sequence than
8949 ICSi(F2), and then */
8951 /* for some argument j, ICSj(F1) is a better conversion sequence than
8954 /* For comparing static and non-static member functions, we ignore
8955 the implicit object parameter of the non-static function. The
8956 standard says to pretend that the static function has an object
8957 parm, but that won't work with operator overloading. */
8958 len = cand1->num_convs;
8959 if (len != cand2->num_convs)
8961 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
8962 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
8964 if (DECL_CONSTRUCTOR_P (cand1->fn)
8965 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn))
8966 /* We're comparing a near-match list constructor and a near-match
8967 non-list constructor. Just treat them as unordered. */
8970 gcc_assert (static_1 != static_2);
8981 for (i = 0; i < len; ++i)
8983 conversion *t1 = cand1->convs[i + off1];
8984 conversion *t2 = cand2->convs[i + off2];
8985 int comp = compare_ics (t1, t2);
8989 if ((complain & tf_warning)
8991 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
8992 == cr_std + cr_promotion)
8993 && t1->kind == ck_std
8994 && t2->kind == ck_std
8995 && TREE_CODE (t1->type) == INTEGER_TYPE
8996 && TREE_CODE (t2->type) == INTEGER_TYPE
8997 && (TYPE_PRECISION (t1->type)
8998 == TYPE_PRECISION (t2->type))
8999 && (TYPE_UNSIGNED (next_conversion (t1)->type)
9000 || (TREE_CODE (next_conversion (t1)->type)
9003 tree type = next_conversion (t1)->type;
9005 struct z_candidate *w, *l;
9007 type1 = t1->type, type2 = t2->type,
9008 w = cand1, l = cand2;
9010 type1 = t2->type, type2 = t1->type,
9011 w = cand2, l = cand1;
9015 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
9016 type, type1, type2);
9017 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
9023 if (winner && comp != winner)
9032 /* warn about confusing overload resolution for user-defined conversions,
9033 either between a constructor and a conversion op, or between two
9035 if ((complain & tf_warning)
9036 && winner && warn_conversion && cand1->second_conv
9037 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
9038 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
9040 struct z_candidate *w, *l;
9041 bool give_warning = false;
9044 w = cand1, l = cand2;
9046 w = cand2, l = cand1;
9048 /* We don't want to complain about `X::operator T1 ()'
9049 beating `X::operator T2 () const', when T2 is a no less
9050 cv-qualified version of T1. */
9051 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
9052 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
9054 tree t = TREE_TYPE (TREE_TYPE (l->fn));
9055 tree f = TREE_TYPE (TREE_TYPE (w->fn));
9057 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
9062 if (!comp_ptr_ttypes (t, f))
9063 give_warning = true;
9066 give_warning = true;
9072 tree source = source_type (w->convs[0]);
9073 if (! DECL_CONSTRUCTOR_P (w->fn))
9074 source = TREE_TYPE (source);
9075 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
9076 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
9077 source, w->second_conv->type))
9079 inform (input_location, " because conversion sequence for the argument is better");
9089 /* DR 495 moved this tiebreaker above the template ones. */
9091 the context is an initialization by user-defined conversion (see
9092 _dcl.init_ and _over.match.user_) and the standard conversion
9093 sequence from the return type of F1 to the destination type (i.e.,
9094 the type of the entity being initialized) is a better conversion
9095 sequence than the standard conversion sequence from the return type
9096 of F2 to the destination type. */
9098 if (cand1->second_conv)
9100 winner = compare_ics (cand1->second_conv, cand2->second_conv);
9106 F1 is a non-template function and F2 is a template function
9109 if (!cand1->template_decl && cand2->template_decl)
9111 else if (cand1->template_decl && !cand2->template_decl)
9115 F1 and F2 are template functions and the function template for F1 is
9116 more specialized than the template for F2 according to the partial
9119 if (cand1->template_decl && cand2->template_decl)
9121 winner = more_specialized_fn
9122 (TI_TEMPLATE (cand1->template_decl),
9123 TI_TEMPLATE (cand2->template_decl),
9124 /* [temp.func.order]: The presence of unused ellipsis and default
9125 arguments has no effect on the partial ordering of function
9126 templates. add_function_candidate() will not have
9127 counted the "this" argument for constructors. */
9128 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
9133 /* Check whether we can discard a builtin candidate, either because we
9134 have two identical ones or matching builtin and non-builtin candidates.
9136 (Pedantically in the latter case the builtin which matched the user
9137 function should not be added to the overload set, but we spot it here.
9140 ... the builtin candidates include ...
9141 - do not have the same parameter type list as any non-template
9142 non-member candidate. */
9144 if (identifier_p (cand1->fn) || identifier_p (cand2->fn))
9146 for (i = 0; i < len; ++i)
9147 if (!same_type_p (cand1->convs[i]->type,
9148 cand2->convs[i]->type))
9150 if (i == cand1->num_convs)
9152 if (cand1->fn == cand2->fn)
9153 /* Two built-in candidates; arbitrarily pick one. */
9155 else if (identifier_p (cand1->fn))
9156 /* cand1 is built-in; prefer cand2. */
9159 /* cand2 is built-in; prefer cand1. */
9164 /* For candidates of a multi-versioned function, make the version with
9165 the highest priority win. This version will be checked for dispatching
9166 first. If this version can be inlined into the caller, the front-end
9167 will simply make a direct call to this function. */
9169 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
9170 && DECL_FUNCTION_VERSIONED (cand1->fn)
9171 && TREE_CODE (cand2->fn) == FUNCTION_DECL
9172 && DECL_FUNCTION_VERSIONED (cand2->fn))
9174 tree f1 = TREE_TYPE (cand1->fn);
9175 tree f2 = TREE_TYPE (cand2->fn);
9176 tree p1 = TYPE_ARG_TYPES (f1);
9177 tree p2 = TYPE_ARG_TYPES (f2);
9179 /* Check if cand1->fn and cand2->fn are versions of the same function. It
9180 is possible that cand1->fn and cand2->fn are function versions but of
9181 different functions. Check types to see if they are versions of the same
9183 if (compparms (p1, p2)
9184 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2)))
9186 /* Always make the version with the higher priority, more
9187 specialized, win. */
9188 gcc_assert (targetm.compare_version_priority);
9189 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0)
9196 /* If the two function declarations represent the same function (this can
9197 happen with declarations in multiple scopes and arg-dependent lookup),
9198 arbitrarily choose one. But first make sure the default args we're
9200 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
9201 && equal_functions (cand1->fn, cand2->fn))
9203 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
9204 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
9206 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
9208 for (i = 0; i < len; ++i)
9210 /* Don't crash if the fn is variadic. */
9213 parms1 = TREE_CHAIN (parms1);
9214 parms2 = TREE_CHAIN (parms2);
9218 parms1 = TREE_CHAIN (parms1);
9220 parms2 = TREE_CHAIN (parms2);
9224 if (!cp_tree_equal (TREE_PURPOSE (parms1),
9225 TREE_PURPOSE (parms2)))
9229 if (complain & tf_error)
9231 if (permerror (input_location,
9232 "default argument mismatch in "
9233 "overload resolution"))
9235 inform (input_location,
9236 " candidate 1: %q+#F", cand1->fn);
9237 inform (input_location,
9238 " candidate 2: %q+#F", cand2->fn);
9245 add_warning (cand1, cand2);
9248 parms1 = TREE_CHAIN (parms1);
9249 parms2 = TREE_CHAIN (parms2);
9257 /* Extension: If the worst conversion for one candidate is worse than the
9258 worst conversion for the other, take the first. */
9259 if (!pedantic && (complain & tf_warning_or_error))
9261 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
9262 struct z_candidate *w = 0, *l = 0;
9264 for (i = 0; i < len; ++i)
9266 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
9267 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
9268 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
9269 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
9272 winner = 1, w = cand1, l = cand2;
9274 winner = -1, w = cand2, l = cand1;
9277 /* Don't choose a deleted function over ambiguity. */
9278 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
9282 pedwarn (input_location, 0,
9283 "ISO C++ says that these are ambiguous, even "
9284 "though the worst conversion for the first is better than "
9285 "the worst conversion for the second:");
9286 print_z_candidate (input_location, _("candidate 1:"), w);
9287 print_z_candidate (input_location, _("candidate 2:"), l);
9295 gcc_assert (!winner);
9299 /* Given a list of candidates for overloading, find the best one, if any.
9300 This algorithm has a worst case of O(2n) (winner is last), and a best
9301 case of O(n/2) (totally ambiguous); much better than a sorting
9304 static struct z_candidate *
9305 tourney (struct z_candidate *candidates, tsubst_flags_t complain)
9307 struct z_candidate *champ = candidates, *challenger;
9309 int champ_compared_to_predecessor = 0;
9311 /* Walk through the list once, comparing each current champ to the next
9312 candidate, knocking out a candidate or two with each comparison. */
9314 for (challenger = champ->next; challenger; )
9316 fate = joust (champ, challenger, 0, complain);
9318 challenger = challenger->next;
9323 champ = challenger->next;
9326 champ_compared_to_predecessor = 0;
9331 champ_compared_to_predecessor = 1;
9334 challenger = champ->next;
9338 /* Make sure the champ is better than all the candidates it hasn't yet
9339 been compared to. */
9341 for (challenger = candidates;
9343 && !(champ_compared_to_predecessor && challenger->next == champ);
9344 challenger = challenger->next)
9346 fate = joust (champ, challenger, 0, complain);
9354 /* Returns nonzero if things of type FROM can be converted to TO. */
9357 can_convert (tree to, tree from, tsubst_flags_t complain)
9359 tree arg = NULL_TREE;
9360 /* implicit_conversion only considers user-defined conversions
9361 if it has an expression for the call argument list. */
9362 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to))
9363 arg = build1 (CAST_EXPR, from, NULL_TREE);
9364 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain);
9367 /* Returns nonzero if things of type FROM can be converted to TO with a
9368 standard conversion. */
9371 can_convert_standard (tree to, tree from, tsubst_flags_t complain)
9373 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain);
9376 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
9379 can_convert_arg (tree to, tree from, tree arg, int flags,
9380 tsubst_flags_t complain)
9386 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9387 p = conversion_obstack_alloc (0);
9388 /* We want to discard any access checks done for this test,
9389 as we might not be in the appropriate access context and
9390 we'll do the check again when we actually perform the
9392 push_deferring_access_checks (dk_deferred);
9394 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
9396 ok_p = (t && !t->bad_p);
9398 /* Discard the access checks now. */
9399 pop_deferring_access_checks ();
9400 /* Free all the conversions we allocated. */
9401 obstack_free (&conversion_obstack, p);
9406 /* Like can_convert_arg, but allows dubious conversions as well. */
9409 can_convert_arg_bad (tree to, tree from, tree arg, int flags,
9410 tsubst_flags_t complain)
9415 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9416 p = conversion_obstack_alloc (0);
9417 /* Try to perform the conversion. */
9418 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
9420 /* Free all the conversions we allocated. */
9421 obstack_free (&conversion_obstack, p);
9426 /* Convert EXPR to TYPE. Return the converted expression.
9428 Note that we allow bad conversions here because by the time we get to
9429 this point we are committed to doing the conversion. If we end up
9430 doing a bad conversion, convert_like will complain. */
9433 perform_implicit_conversion_flags (tree type, tree expr,
9434 tsubst_flags_t complain, int flags)
9438 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
9440 if (error_operand_p (expr))
9441 return error_mark_node;
9443 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9444 p = conversion_obstack_alloc (0);
9446 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
9452 if (complain & tf_error)
9454 /* If expr has unknown type, then it is an overloaded function.
9455 Call instantiate_type to get good error messages. */
9456 if (TREE_TYPE (expr) == unknown_type_node)
9457 instantiate_type (type, expr, complain);
9458 else if (invalid_nonstatic_memfn_p (expr, complain))
9459 /* We gave an error. */;
9461 error_at (loc, "could not convert %qE from %qT to %qT", expr,
9462 TREE_TYPE (expr), type);
9464 expr = error_mark_node;
9466 else if (processing_template_decl && conv->kind != ck_identity)
9468 /* In a template, we are only concerned about determining the
9469 type of non-dependent expressions, so we do not have to
9470 perform the actual conversion. But for initializers, we
9471 need to be able to perform it at instantiation
9472 (or instantiate_non_dependent_expr) time. */
9473 expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
9474 if (!(flags & LOOKUP_ONLYCONVERTING))
9475 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
9478 expr = convert_like (conv, expr, complain);
9480 /* Free all the conversions we allocated. */
9481 obstack_free (&conversion_obstack, p);
9487 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
9489 return perform_implicit_conversion_flags (type, expr, complain,
9493 /* Convert EXPR to TYPE (as a direct-initialization) if that is
9494 permitted. If the conversion is valid, the converted expression is
9495 returned. Otherwise, NULL_TREE is returned, except in the case
9496 that TYPE is a class type; in that case, an error is issued. If
9497 C_CAST_P is true, then this direct-initialization is taking
9498 place as part of a static_cast being attempted as part of a C-style
9502 perform_direct_initialization_if_possible (tree type,
9505 tsubst_flags_t complain)
9510 if (type == error_mark_node || error_operand_p (expr))
9511 return error_mark_node;
9514 If the destination type is a (possibly cv-qualified) class type:
9516 -- If the initialization is direct-initialization ...,
9517 constructors are considered. ... If no constructor applies, or
9518 the overload resolution is ambiguous, the initialization is
9520 if (CLASS_TYPE_P (type))
9522 vec<tree, va_gc> *args = make_tree_vector_single (expr);
9523 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
9524 &args, type, LOOKUP_NORMAL, complain);
9525 release_tree_vector (args);
9526 return build_cplus_new (type, expr, complain);
9529 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9530 p = conversion_obstack_alloc (0);
9532 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
9534 LOOKUP_NORMAL, complain);
9535 if (!conv || conv->bad_p)
9538 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
9539 /*issue_conversion_warnings=*/false,
9543 /* Free all the conversions we allocated. */
9544 obstack_free (&conversion_obstack, p);
9549 /* When initializing a reference that lasts longer than a full-expression,
9550 this special rule applies:
9554 The temporary to which the reference is bound or the temporary
9555 that is the complete object to which the reference is bound
9556 persists for the lifetime of the reference.
9558 The temporaries created during the evaluation of the expression
9559 initializing the reference, except the temporary to which the
9560 reference is bound, are destroyed at the end of the
9561 full-expression in which they are created.
9563 In that case, we store the converted expression into a new
9564 VAR_DECL in a new scope.
9566 However, we want to be careful not to create temporaries when
9567 they are not required. For example, given:
9570 struct D : public B {};
9574 there is no need to copy the return value from "f"; we can just
9575 extend its lifetime. Similarly, given:
9578 struct T { operator S(); };
9582 we can extend the lifetime of the return value of the conversion
9585 The next several functions are involved in this lifetime extension. */
9587 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The
9588 reference is being bound to a temporary. Create and return a new
9589 VAR_DECL with the indicated TYPE; this variable will store the value to
9590 which the reference is bound. */
9593 make_temporary_var_for_ref_to_temp (tree decl, tree type)
9597 /* Create the variable. */
9598 var = create_temporary_var (type);
9600 /* Register the variable. */
9602 && (TREE_STATIC (decl) || DECL_THREAD_LOCAL_P (decl)))
9604 /* Namespace-scope or local static; give it a mangled name. */
9605 /* FIXME share comdat with decl? */
9608 TREE_STATIC (var) = TREE_STATIC (decl);
9609 set_decl_tls_model (var, DECL_TLS_MODEL (decl));
9610 name = mangle_ref_init_variable (decl);
9611 DECL_NAME (var) = name;
9612 SET_DECL_ASSEMBLER_NAME (var, name);
9613 var = pushdecl_top_level (var);
9616 /* Create a new cleanup level if necessary. */
9617 maybe_push_cleanup_level (type);
9622 /* EXPR is the initializer for a variable DECL of reference or
9623 std::initializer_list type. Create, push and return a new VAR_DECL
9624 for the initializer so that it will live as long as DECL. Any
9625 cleanup for the new variable is returned through CLEANUP, and the
9626 code to initialize the new variable is returned through INITP. */
9629 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups,
9636 /* Create the temporary variable. */
9637 type = TREE_TYPE (expr);
9638 var = make_temporary_var_for_ref_to_temp (decl, type);
9639 layout_decl (var, 0);
9640 /* If the rvalue is the result of a function call it will be
9641 a TARGET_EXPR. If it is some other construct (such as a
9642 member access expression where the underlying object is
9643 itself the result of a function call), turn it into a
9644 TARGET_EXPR here. It is important that EXPR be a
9645 TARGET_EXPR below since otherwise the INIT_EXPR will
9646 attempt to make a bitwise copy of EXPR to initialize
9648 if (TREE_CODE (expr) != TARGET_EXPR)
9649 expr = get_target_expr (expr);
9651 if (TREE_CODE (decl) == FIELD_DECL
9652 && extra_warnings && !TREE_NO_WARNING (decl))
9654 warning (OPT_Wextra, "a temporary bound to %qD only persists "
9655 "until the constructor exits", decl);
9656 TREE_NO_WARNING (decl) = true;
9659 /* Recursively extend temps in this initializer. */
9660 TARGET_EXPR_INITIAL (expr)
9661 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups);
9663 /* Any reference temp has a non-trivial initializer. */
9664 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true;
9666 /* If the initializer is constant, put it in DECL_INITIAL so we get
9667 static initialization and use in constant expressions. */
9668 init = maybe_constant_init (expr);
9669 if (TREE_CONSTANT (init))
9671 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
9673 /* 5.19 says that a constant expression can include an
9674 lvalue-rvalue conversion applied to "a glvalue of literal type
9675 that refers to a non-volatile temporary object initialized
9676 with a constant expression". Rather than try to communicate
9677 that this VAR_DECL is a temporary, just mark it constexpr.
9679 Currently this is only useful for initializer_list temporaries,
9680 since reference vars can't appear in constant expressions. */
9681 DECL_DECLARED_CONSTEXPR_P (var) = true;
9682 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
9683 TREE_CONSTANT (var) = true;
9685 DECL_INITIAL (var) = init;
9689 /* Create the INIT_EXPR that will initialize the temporary
9691 init = split_nonconstant_init (var, expr);
9692 if (at_function_scope_p ())
9694 add_decl_expr (var);
9696 if (TREE_STATIC (var))
9697 init = add_stmt_to_compound (init, register_dtor_fn (var));
9700 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error);
9702 vec_safe_push (*cleanups, cleanup);
9705 /* We must be careful to destroy the temporary only
9706 after its initialization has taken place. If the
9707 initialization throws an exception, then the
9708 destructor should not be run. We cannot simply
9709 transform INIT into something like:
9711 (INIT, ({ CLEANUP_STMT; }))
9713 because emit_local_var always treats the
9714 initializer as a full-expression. Thus, the
9715 destructor would run too early; it would run at the
9716 end of initializing the reference variable, rather
9717 than at the end of the block enclosing the
9720 The solution is to pass back a cleanup expression
9721 which the caller is responsible for attaching to
9722 the statement tree. */
9726 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
9727 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
9729 if (DECL_THREAD_LOCAL_P (var))
9730 tls_aggregates = tree_cons (NULL_TREE, var,
9733 static_aggregates = tree_cons (NULL_TREE, var,
9737 /* Check whether the dtor is callable. */
9738 cxx_maybe_build_cleanup (var, tf_warning_or_error);
9740 /* Avoid -Wunused-variable warning (c++/38958). */
9741 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
9742 && TREE_CODE (decl) == VAR_DECL)
9743 TREE_USED (decl) = DECL_READ_P (decl) = true;
9749 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
9750 initializing a variable of that TYPE. */
9753 initialize_reference (tree type, tree expr,
9754 int flags, tsubst_flags_t complain)
9758 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
9760 if (type == error_mark_node || error_operand_p (expr))
9761 return error_mark_node;
9763 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9764 p = conversion_obstack_alloc (0);
9766 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
9768 if (!conv || conv->bad_p)
9770 if (complain & tf_error)
9773 convert_like (conv, expr, complain);
9774 else if (!CP_TYPE_CONST_P (TREE_TYPE (type))
9775 && !TYPE_REF_IS_RVALUE (type)
9776 && !real_lvalue_p (expr))
9777 error_at (loc, "invalid initialization of non-const reference of "
9778 "type %qT from an rvalue of type %qT",
9779 type, TREE_TYPE (expr));
9781 error_at (loc, "invalid initialization of reference of type "
9782 "%qT from expression of type %qT", type,
9785 return error_mark_node;
9788 if (conv->kind == ck_ref_bind)
9789 /* Perform the conversion. */
9790 expr = convert_like (conv, expr, complain);
9791 else if (conv->kind == ck_ambig)
9792 /* We gave an error in build_user_type_conversion_1. */
9793 expr = error_mark_node;
9797 /* Free all the conversions we allocated. */
9798 obstack_free (&conversion_obstack, p);
9803 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer,
9804 which is bound either to a reference or a std::initializer_list. */
9807 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups)
9812 if (TREE_CODE (sub) == COMPOUND_EXPR)
9814 TREE_OPERAND (sub, 1)
9815 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups);
9818 if (TREE_CODE (sub) != ADDR_EXPR)
9820 /* Deal with binding to a subobject. */
9821 for (p = &TREE_OPERAND (sub, 0); TREE_CODE (*p) == COMPONENT_REF; )
9822 p = &TREE_OPERAND (*p, 0);
9823 if (TREE_CODE (*p) == TARGET_EXPR)
9825 tree subinit = NULL_TREE;
9826 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit);
9827 recompute_tree_invariant_for_addr_expr (sub);
9829 init = fold_convert (TREE_TYPE (init), sub);
9831 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init);
9836 /* INIT is part of the initializer for DECL. If there are any
9837 reference or initializer lists being initialized, extend their
9838 lifetime to match that of DECL. */
9841 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups)
9843 tree type = TREE_TYPE (init);
9844 if (processing_template_decl)
9846 if (TREE_CODE (type) == REFERENCE_TYPE)
9847 init = extend_ref_init_temps_1 (decl, init, cleanups);
9848 else if (is_std_init_list (type))
9850 /* The temporary array underlying a std::initializer_list
9851 is handled like a reference temporary. */
9853 if (TREE_CODE (ctor) == TARGET_EXPR)
9854 ctor = TARGET_EXPR_INITIAL (ctor);
9855 if (TREE_CODE (ctor) == CONSTRUCTOR)
9857 tree array = CONSTRUCTOR_ELT (ctor, 0)->value;
9858 array = extend_ref_init_temps_1 (decl, array, cleanups);
9859 CONSTRUCTOR_ELT (ctor, 0)->value = array;
9862 else if (TREE_CODE (init) == CONSTRUCTOR)
9866 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (init);
9867 FOR_EACH_VEC_SAFE_ELT (elts, i, p)
9868 p->value = extend_ref_init_temps (decl, p->value, cleanups);
9874 /* Returns true iff an initializer for TYPE could contain temporaries that
9875 need to be extended because they are bound to references or
9876 std::initializer_list. */
9879 type_has_extended_temps (tree type)
9881 type = strip_array_types (type);
9882 if (TREE_CODE (type) == REFERENCE_TYPE)
9884 if (CLASS_TYPE_P (type))
9886 if (is_std_init_list (type))
9888 for (tree f = next_initializable_field (TYPE_FIELDS (type));
9889 f; f = next_initializable_field (DECL_CHAIN (f)))
9890 if (type_has_extended_temps (TREE_TYPE (f)))
9896 /* Returns true iff TYPE is some variant of std::initializer_list. */
9899 is_std_init_list (tree type)
9901 /* Look through typedefs. */
9904 if (cxx_dialect == cxx98)
9906 type = TYPE_MAIN_VARIANT (type);
9907 return (CLASS_TYPE_P (type)
9908 && CP_TYPE_CONTEXT (type) == std_node
9909 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
9912 /* Returns true iff DECL is a list constructor: i.e. a constructor which
9913 will accept an argument list of a single std::initializer_list<T>. */
9916 is_list_ctor (tree decl)
9918 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
9921 if (!args || args == void_list_node)
9924 arg = non_reference (TREE_VALUE (args));
9925 if (!is_std_init_list (arg))
9928 args = TREE_CHAIN (args);
9930 if (args && args != void_list_node && !TREE_PURPOSE (args))
9931 /* There are more non-defaulted parms. */
9937 #include "gt-cp-call.h"