1 /* Functions related to invoking -*- C++ -*- methods and overloaded functions.
2 Copyright (C) 1987-2018 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"
31 #include "stringpool.h"
33 #include "stor-layout.h"
34 #include "trans-mem.h"
39 #include "langhooks.h"
40 #include "c-family/c-objc.h"
41 #include "internal-fn.h"
42 #include "stringpool.h"
45 /* The various kinds of conversion. */
47 enum conversion_kind {
64 /* The rank of the conversion. Order of the enumerals matters; better
65 conversions should come earlier in the list. */
67 enum conversion_rank {
78 /* An implicit conversion sequence, in the sense of [over.best.ics].
79 The first conversion to be performed is at the end of the chain.
80 That conversion is always a cr_identity conversion. */
83 /* The kind of conversion represented by this step. */
85 /* The rank of this conversion. */
87 BOOL_BITFIELD user_conv_p : 1;
88 BOOL_BITFIELD ellipsis_p : 1;
89 BOOL_BITFIELD this_p : 1;
90 /* True if this conversion would be permitted with a bending of
91 language standards, e.g. disregarding pointer qualifiers or
92 converting integers to pointers. */
93 BOOL_BITFIELD bad_p : 1;
94 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
95 temporary should be created to hold the result of the
96 conversion. If KIND is ck_ambig, true if the context is
97 copy-initialization. */
98 BOOL_BITFIELD need_temporary_p : 1;
99 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
100 from a pointer-to-derived to pointer-to-base is being performed. */
101 BOOL_BITFIELD base_p : 1;
102 /* If KIND is ck_ref_bind, true when either an lvalue reference is
103 being bound to an lvalue expression or an rvalue reference is
104 being bound to an rvalue expression. If KIND is ck_rvalue,
105 true when we are treating an lvalue as an rvalue (12.8p33). If
106 KIND is ck_base, always false. If ck_identity, we will be
107 binding a reference directly or decaying to a pointer. */
108 BOOL_BITFIELD rvaluedness_matches_p: 1;
109 BOOL_BITFIELD check_narrowing: 1;
110 /* The type of the expression resulting from the conversion. */
113 /* The next conversion in the chain. Since the conversions are
114 arranged from outermost to innermost, the NEXT conversion will
115 actually be performed before this conversion. This variant is
116 used only when KIND is neither ck_identity, ck_ambig nor
117 ck_list. Please use the next_conversion function instead
118 of using this field directly. */
120 /* The expression at the beginning of the conversion chain. This
121 variant is used only if KIND is ck_identity or ck_ambig. */
123 /* The array of conversions for an initializer_list, so this
124 variant is used only when KIN D is ck_list. */
127 /* The function candidate corresponding to this conversion
128 sequence. This field is only used if KIND is ck_user. */
129 struct z_candidate *cand;
132 #define CONVERSION_RANK(NODE) \
133 ((NODE)->bad_p ? cr_bad \
134 : (NODE)->ellipsis_p ? cr_ellipsis \
135 : (NODE)->user_conv_p ? cr_user \
138 #define BAD_CONVERSION_RANK(NODE) \
139 ((NODE)->ellipsis_p ? cr_ellipsis \
140 : (NODE)->user_conv_p ? cr_user \
143 static struct obstack conversion_obstack;
144 static bool conversion_obstack_initialized;
145 struct rejection_reason;
147 static struct z_candidate * tourney (struct z_candidate *, tsubst_flags_t);
148 static int equal_functions (tree, tree);
149 static int joust (struct z_candidate *, struct z_candidate *, bool,
151 static int compare_ics (conversion *, conversion *);
152 static void maybe_warn_class_memaccess (location_t, tree,
153 const vec<tree, va_gc> *);
154 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
155 #define convert_like(CONV, EXPR, COMPLAIN) \
156 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, \
157 /*issue_conversion_warnings=*/true, \
158 /*c_cast_p=*/false, (COMPLAIN))
159 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
160 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), \
161 /*issue_conversion_warnings=*/true, \
162 /*c_cast_p=*/false, (COMPLAIN))
163 static tree convert_like_real (conversion *, tree, tree, int, bool,
164 bool, tsubst_flags_t);
165 static void op_error (location_t, enum tree_code, enum tree_code, tree,
167 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int,
169 static void print_z_candidate (location_t, const char *, struct z_candidate *);
170 static void print_z_candidates (location_t, struct z_candidate *);
171 static tree build_this (tree);
172 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
173 static bool any_strictly_viable (struct z_candidate *);
174 static struct z_candidate *add_template_candidate
175 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
176 tree, tree, tree, int, unification_kind_t, tsubst_flags_t);
177 static struct z_candidate *add_template_candidate_real
178 (struct z_candidate **, tree, tree, tree, tree, const vec<tree, va_gc> *,
179 tree, tree, tree, int, tree, unification_kind_t, tsubst_flags_t);
180 static void add_builtin_candidates
181 (struct z_candidate **, enum tree_code, enum tree_code,
182 tree, tree *, int, tsubst_flags_t);
183 static void add_builtin_candidate
184 (struct z_candidate **, enum tree_code, enum tree_code,
185 tree, tree, tree, tree *, tree *, int, tsubst_flags_t);
186 static bool is_complete (tree);
187 static void build_builtin_candidate
188 (struct z_candidate **, tree, tree, tree, tree *, tree *,
189 int, tsubst_flags_t);
190 static struct z_candidate *add_conv_candidate
191 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, tree,
192 tree, tsubst_flags_t);
193 static struct z_candidate *add_function_candidate
194 (struct z_candidate **, tree, tree, tree, const vec<tree, va_gc> *, tree,
195 tree, int, tsubst_flags_t);
196 static conversion *implicit_conversion (tree, tree, tree, bool, int,
198 static conversion *reference_binding (tree, tree, tree, bool, int,
200 static conversion *build_conv (conversion_kind, tree, conversion *);
201 static conversion *build_list_conv (tree, tree, int, tsubst_flags_t);
202 static conversion *next_conversion (conversion *);
203 static bool is_subseq (conversion *, conversion *);
204 static conversion *maybe_handle_ref_bind (conversion **);
205 static void maybe_handle_implicit_object (conversion **);
206 static struct z_candidate *add_candidate
207 (struct z_candidate **, tree, tree, const vec<tree, va_gc> *, size_t,
208 conversion **, tree, tree, int, struct rejection_reason *, int);
209 static tree source_type (conversion *);
210 static void add_warning (struct z_candidate *, struct z_candidate *);
211 static bool reference_compatible_p (tree, tree);
212 static conversion *direct_reference_binding (tree, conversion *);
213 static bool promoted_arithmetic_type_p (tree);
214 static conversion *conditional_conversion (tree, tree, tsubst_flags_t);
215 static char *name_as_c_string (tree, tree, bool *);
216 static tree prep_operand (tree);
217 static void add_candidates (tree, tree, const vec<tree, va_gc> *, tree, tree,
218 bool, tree, tree, int, struct z_candidate **,
220 static conversion *merge_conversion_sequences (conversion *, conversion *);
221 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
223 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
224 NAME can take many forms... */
227 check_dtor_name (tree basetype, tree name)
229 /* Just accept something we've already complained about. */
230 if (name == error_mark_node)
233 if (TREE_CODE (name) == TYPE_DECL)
234 name = TREE_TYPE (name);
235 else if (TYPE_P (name))
237 else if (identifier_p (name))
239 if ((MAYBE_CLASS_TYPE_P (basetype)
240 || TREE_CODE (basetype) == ENUMERAL_TYPE)
241 && name == constructor_name (basetype))
244 name = get_type_value (name);
250 template <class T> struct S { ~S(); };
254 NAME will be a class template. */
255 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
259 if (!name || name == error_mark_node)
261 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
264 /* We want the address of a function or method. We avoid creating a
265 pointer-to-member function. */
268 build_addr_func (tree function, tsubst_flags_t complain)
270 tree type = TREE_TYPE (function);
272 /* We have to do these by hand to avoid real pointer to member
274 if (TREE_CODE (type) == METHOD_TYPE)
276 if (TREE_CODE (function) == OFFSET_REF)
278 tree object = build_address (TREE_OPERAND (function, 0));
279 return get_member_function_from_ptrfunc (&object,
280 TREE_OPERAND (function, 1),
283 function = build_address (function);
286 function = decay_conversion (function, complain, /*reject_builtin=*/false);
291 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
292 POINTER_TYPE to those. Note, pointer to member function types
293 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
294 two variants. build_call_a is the primitive taking an array of
295 arguments, while build_call_n is a wrapper that handles varargs. */
298 build_call_n (tree function, int n, ...)
301 return build_call_a (function, 0, NULL);
304 tree *argarray = XALLOCAVEC (tree, n);
309 for (i = 0; i < n; i++)
310 argarray[i] = va_arg (ap, tree);
312 return build_call_a (function, n, argarray);
316 /* Update various flags in cfun and the call itself based on what is being
317 called. Split out of build_call_a so that bot_manip can use it too. */
320 set_flags_from_callee (tree call)
323 tree decl = get_callee_fndecl (call);
325 /* We check both the decl and the type; a function may be known not to
326 throw without being declared throw(). */
327 nothrow = decl && TREE_NOTHROW (decl);
328 if (CALL_EXPR_FN (call))
329 nothrow |= TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (CALL_EXPR_FN (call))));
330 else if (internal_fn_flags (CALL_EXPR_IFN (call)) & ECF_NOTHROW)
333 if (!nothrow && at_function_scope_p () && cfun && cp_function_chain)
334 cp_function_chain->can_throw = 1;
336 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
337 current_function_returns_abnormally = 1;
339 TREE_NOTHROW (call) = nothrow;
343 build_call_a (tree function, int n, tree *argarray)
350 function = build_addr_func (function, tf_warning_or_error);
352 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
353 fntype = TREE_TYPE (TREE_TYPE (function));
354 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
355 || TREE_CODE (fntype) == METHOD_TYPE);
356 result_type = TREE_TYPE (fntype);
357 /* An rvalue has no cv-qualifiers. */
358 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
359 result_type = cv_unqualified (result_type);
361 function = build_call_array_loc (input_location,
362 result_type, function, n, argarray);
363 set_flags_from_callee (function);
365 decl = get_callee_fndecl (function);
367 if (decl && !TREE_USED (decl))
369 /* We invoke build_call directly for several library
370 functions. These may have been declared normally if
371 we're building libgcc, so we can't just check
373 gcc_assert (DECL_ARTIFICIAL (decl)
374 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
379 require_complete_eh_spec_types (fntype, decl);
381 TREE_HAS_CONSTRUCTOR (function) = (decl && DECL_CONSTRUCTOR_P (decl));
383 /* Don't pass empty class objects by value. This is useful
384 for tags in STL, which are used to control overload resolution.
385 We don't need to handle other cases of copying empty classes. */
386 if (! decl || ! DECL_BUILT_IN (decl))
387 for (i = 0; i < n; i++)
389 tree arg = CALL_EXPR_ARG (function, i);
390 if (is_empty_class (TREE_TYPE (arg))
391 && ! TREE_ADDRESSABLE (TREE_TYPE (arg)))
393 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (arg));
394 arg = build2 (COMPOUND_EXPR, TREE_TYPE (t), arg, t);
395 CALL_EXPR_ARG (function, i) = arg;
402 /* New overloading code. */
406 struct candidate_warning {
408 candidate_warning *next;
411 /* Information for providing diagnostics about why overloading failed. */
413 enum rejection_reason_code {
416 rr_explicit_conversion,
417 rr_template_conversion,
419 rr_bad_arg_conversion,
420 rr_template_unification,
423 rr_constraint_failure
426 struct conversion_info {
427 /* The index of the argument, 0-based. */
429 /* The actual argument or its type. */
431 /* The type of the parameter. */
435 struct rejection_reason {
436 enum rejection_reason_code code;
438 /* Information about an arity mismatch. */
440 /* The expected number of arguments. */
442 /* The actual number of arguments in the call. */
444 /* Whether the call was a varargs call. */
447 /* Information about an argument conversion mismatch. */
448 struct conversion_info conversion;
449 /* Same, but for bad argument conversions. */
450 struct conversion_info bad_conversion;
451 /* Information about template unification failures. These are the
452 parameters passed to fn_type_unification. */
460 unification_kind_t strict;
462 } template_unification;
463 /* Information about template instantiation failures. These are the
464 parameters passed to instantiate_template. */
468 } template_instantiation;
473 /* The FUNCTION_DECL that will be called if this candidate is
474 selected by overload resolution. */
476 /* If not NULL_TREE, the first argument to use when calling this
479 /* The rest of the arguments to use when calling this function. If
480 there are no further arguments this may be NULL or it may be an
482 const vec<tree, va_gc> *args;
483 /* The implicit conversion sequences for each of the arguments to
486 /* The number of implicit conversion sequences. */
488 /* If FN is a user-defined conversion, the standard conversion
489 sequence from the type returned by FN to the desired destination
491 conversion *second_conv;
492 struct rejection_reason *reason;
493 /* If FN is a member function, the binfo indicating the path used to
494 qualify the name of FN at the call site. This path is used to
495 determine whether or not FN is accessible if it is selected by
496 overload resolution. The DECL_CONTEXT of FN will always be a
497 (possibly improper) base of this binfo. */
499 /* If FN is a non-static member function, the binfo indicating the
500 subobject to which the `this' pointer should be converted if FN
501 is selected by overload resolution. The type pointed to by
502 the `this' pointer must correspond to the most derived class
503 indicated by the CONVERSION_PATH. */
504 tree conversion_path;
507 candidate_warning *warnings;
511 /* The flags active in add_candidate. */
515 /* Returns true iff T is a null pointer constant in the sense of
519 null_ptr_cst_p (tree t)
521 tree type = TREE_TYPE (t);
525 A null pointer constant is an integral constant expression
526 (_expr.const_) rvalue of integer type that evaluates to zero or
527 an rvalue of type std::nullptr_t. */
528 if (NULLPTR_TYPE_P (type))
531 if (cxx_dialect >= cxx11)
533 STRIP_ANY_LOCATION_WRAPPER (t);
535 /* Core issue 903 says only literal 0 is a null pointer constant. */
536 if (TREE_CODE (type) == INTEGER_TYPE
537 && !char_type_p (type)
538 && TREE_CODE (t) == INTEGER_CST
540 && !TREE_OVERFLOW (t))
543 else if (CP_INTEGRAL_TYPE_P (type))
545 t = fold_non_dependent_expr (t);
547 if (integer_zerop (t) && !TREE_OVERFLOW (t))
554 /* Returns true iff T is a null member pointer value (4.11). */
557 null_member_pointer_value_p (tree t)
559 tree type = TREE_TYPE (t);
562 else if (TYPE_PTRMEMFUNC_P (type))
563 return (TREE_CODE (t) == CONSTRUCTOR
564 && integer_zerop (CONSTRUCTOR_ELT (t, 0)->value));
565 else if (TYPE_PTRDATAMEM_P (type))
566 return integer_all_onesp (t);
571 /* Returns nonzero if PARMLIST consists of only default parms,
572 ellipsis, and/or undeduced parameter packs. */
575 sufficient_parms_p (const_tree parmlist)
577 for (; parmlist && parmlist != void_list_node;
578 parmlist = TREE_CHAIN (parmlist))
579 if (!TREE_PURPOSE (parmlist)
580 && !PACK_EXPANSION_P (TREE_VALUE (parmlist)))
585 /* Allocate N bytes of memory from the conversion obstack. The memory
586 is zeroed before being returned. */
589 conversion_obstack_alloc (size_t n)
592 if (!conversion_obstack_initialized)
594 gcc_obstack_init (&conversion_obstack);
595 conversion_obstack_initialized = true;
597 p = obstack_alloc (&conversion_obstack, n);
602 /* Allocate rejection reasons. */
604 static struct rejection_reason *
605 alloc_rejection (enum rejection_reason_code code)
607 struct rejection_reason *p;
608 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
613 static struct rejection_reason *
614 arity_rejection (tree first_arg, int expected, int actual)
616 struct rejection_reason *r = alloc_rejection (rr_arity);
617 int adjust = first_arg != NULL_TREE;
618 r->u.arity.expected = expected - adjust;
619 r->u.arity.actual = actual - adjust;
623 static struct rejection_reason *
624 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
626 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
627 int adjust = first_arg != NULL_TREE;
628 r->u.conversion.n_arg = n_arg - adjust;
629 r->u.conversion.from = from;
630 r->u.conversion.to_type = to;
634 static struct rejection_reason *
635 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
637 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
638 int adjust = first_arg != NULL_TREE;
639 r->u.bad_conversion.n_arg = n_arg - adjust;
640 r->u.bad_conversion.from = from;
641 r->u.bad_conversion.to_type = to;
645 static struct rejection_reason *
646 explicit_conversion_rejection (tree from, tree to)
648 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion);
649 r->u.conversion.n_arg = 0;
650 r->u.conversion.from = from;
651 r->u.conversion.to_type = to;
655 static struct rejection_reason *
656 template_conversion_rejection (tree from, tree to)
658 struct rejection_reason *r = alloc_rejection (rr_template_conversion);
659 r->u.conversion.n_arg = 0;
660 r->u.conversion.from = from;
661 r->u.conversion.to_type = to;
665 static struct rejection_reason *
666 template_unification_rejection (tree tmpl, tree explicit_targs, tree targs,
667 const tree *args, unsigned int nargs,
668 tree return_type, unification_kind_t strict,
671 size_t args_n_bytes = sizeof (*args) * nargs;
672 tree *args1 = (tree *) conversion_obstack_alloc (args_n_bytes);
673 struct rejection_reason *r = alloc_rejection (rr_template_unification);
674 r->u.template_unification.tmpl = tmpl;
675 r->u.template_unification.explicit_targs = explicit_targs;
676 r->u.template_unification.num_targs = TREE_VEC_LENGTH (targs);
677 /* Copy args to our own storage. */
678 memcpy (args1, args, args_n_bytes);
679 r->u.template_unification.args = args1;
680 r->u.template_unification.nargs = nargs;
681 r->u.template_unification.return_type = return_type;
682 r->u.template_unification.strict = strict;
683 r->u.template_unification.flags = flags;
687 static struct rejection_reason *
688 template_unification_error_rejection (void)
690 return alloc_rejection (rr_template_unification);
693 static struct rejection_reason *
694 invalid_copy_with_fn_template_rejection (void)
696 struct rejection_reason *r = alloc_rejection (rr_invalid_copy);
700 static struct rejection_reason *
701 inherited_ctor_rejection (void)
703 struct rejection_reason *r = alloc_rejection (rr_inherited_ctor);
707 // Build a constraint failure record, saving information into the
708 // template_instantiation field of the rejection. If FN is not a template
709 // declaration, the TMPL member is the FN declaration and TARGS is empty.
711 static struct rejection_reason *
712 constraint_failure (tree fn)
714 struct rejection_reason *r = alloc_rejection (rr_constraint_failure);
715 if (tree ti = DECL_TEMPLATE_INFO (fn))
717 r->u.template_instantiation.tmpl = TI_TEMPLATE (ti);
718 r->u.template_instantiation.targs = TI_ARGS (ti);
722 r->u.template_instantiation.tmpl = fn;
723 r->u.template_instantiation.targs = NULL_TREE;
728 /* Dynamically allocate a conversion. */
731 alloc_conversion (conversion_kind kind)
734 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
739 /* Make sure that all memory on the conversion obstack has been
743 validate_conversion_obstack (void)
745 if (conversion_obstack_initialized)
746 gcc_assert ((obstack_next_free (&conversion_obstack)
747 == obstack_base (&conversion_obstack)));
750 /* Dynamically allocate an array of N conversions. */
753 alloc_conversions (size_t n)
755 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
759 build_conv (conversion_kind code, tree type, conversion *from)
762 conversion_rank rank = CONVERSION_RANK (from);
764 /* Note that the caller is responsible for filling in t->cand for
765 user-defined conversions. */
766 t = alloc_conversion (code);
790 t->user_conv_p = (code == ck_user || from->user_conv_p);
791 t->bad_p = from->bad_p;
796 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
797 specialization of std::initializer_list<T>, if such a conversion is
801 build_list_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
803 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
804 unsigned len = CONSTRUCTOR_NELTS (ctor);
805 conversion **subconvs = alloc_conversions (len);
810 /* Within a list-initialization we can have more user-defined
812 flags &= ~LOOKUP_NO_CONVERSION;
813 /* But no narrowing conversions. */
814 flags |= LOOKUP_NO_NARROWING;
816 /* Can't make an array of these types. */
817 if (TREE_CODE (elttype) == REFERENCE_TYPE
818 || TREE_CODE (elttype) == FUNCTION_TYPE
819 || VOID_TYPE_P (elttype))
822 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
825 = implicit_conversion (elttype, TREE_TYPE (val), val,
826 false, flags, complain);
833 t = alloc_conversion (ck_list);
835 t->u.list = subconvs;
838 for (i = 0; i < len; ++i)
840 conversion *sub = subconvs[i];
841 if (sub->rank > t->rank)
843 if (sub->user_conv_p)
844 t->user_conv_p = true;
852 /* Return the next conversion of the conversion chain (if applicable),
853 or NULL otherwise. Please use this function instead of directly
854 accessing fields of struct conversion. */
857 next_conversion (conversion *conv)
860 || conv->kind == ck_identity
861 || conv->kind == ck_ambig
862 || conv->kind == ck_list)
867 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
868 is a valid aggregate initializer for array type ATYPE. */
871 can_convert_array (tree atype, tree ctor, int flags, tsubst_flags_t complain)
874 tree elttype = TREE_TYPE (atype);
875 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
877 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
879 if (TREE_CODE (elttype) == ARRAY_TYPE
880 && TREE_CODE (val) == CONSTRUCTOR)
881 ok = can_convert_array (elttype, val, flags, complain);
883 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags,
891 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
892 aggregate class, if such a conversion is possible. */
895 build_aggr_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
897 unsigned HOST_WIDE_INT i = 0;
899 tree field = next_initializable_field (TYPE_FIELDS (type));
900 tree empty_ctor = NULL_TREE;
902 /* We already called reshape_init in implicit_conversion. */
904 /* The conversions within the init-list aren't affected by the enclosing
905 context; they're always simple copy-initialization. */
906 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
908 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
910 tree ftype = TREE_TYPE (field);
914 if (i < CONSTRUCTOR_NELTS (ctor))
915 val = CONSTRUCTOR_ELT (ctor, i)->value;
916 else if (DECL_INITIAL (field))
917 val = get_nsdmi (field, /*ctor*/false, complain);
918 else if (TREE_CODE (ftype) == REFERENCE_TYPE)
919 /* Value-initialization of reference is ill-formed. */
923 if (empty_ctor == NULL_TREE)
924 empty_ctor = build_constructor (init_list_type_node, NULL);
929 if (TREE_CODE (ftype) == ARRAY_TYPE
930 && TREE_CODE (val) == CONSTRUCTOR)
931 ok = can_convert_array (ftype, val, flags, complain);
933 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags,
939 if (TREE_CODE (type) == UNION_TYPE)
943 if (i < CONSTRUCTOR_NELTS (ctor))
946 c = alloc_conversion (ck_aggr);
949 c->user_conv_p = true;
950 c->check_narrowing = true;
955 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
956 array type, if such a conversion is possible. */
959 build_array_conv (tree type, tree ctor, int flags, tsubst_flags_t complain)
962 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
963 tree elttype = TREE_TYPE (type);
968 enum conversion_rank rank = cr_exact;
970 /* We might need to propagate the size from the element to the array. */
971 complete_type (type);
973 if (TYPE_DOMAIN (type)
974 && !variably_modified_type_p (TYPE_DOMAIN (type), NULL_TREE))
976 unsigned HOST_WIDE_INT alen = tree_to_uhwi (array_type_nelts_top (type));
981 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
983 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
986 = implicit_conversion (elttype, TREE_TYPE (val), val,
987 false, flags, complain);
991 if (sub->rank > rank)
993 if (sub->user_conv_p)
999 c = alloc_conversion (ck_aggr);
1002 c->user_conv_p = user;
1008 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
1009 complex type, if such a conversion is possible. */
1012 build_complex_conv (tree type, tree ctor, int flags,
1013 tsubst_flags_t complain)
1016 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
1017 tree elttype = TREE_TYPE (type);
1022 enum conversion_rank rank = cr_exact;
1027 flags = LOOKUP_IMPLICIT|LOOKUP_NO_NARROWING;
1029 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
1032 = implicit_conversion (elttype, TREE_TYPE (val), val,
1033 false, flags, complain);
1037 if (sub->rank > rank)
1039 if (sub->user_conv_p)
1045 c = alloc_conversion (ck_aggr);
1048 c->user_conv_p = user;
1054 /* Build a representation of the identity conversion from EXPR to
1055 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
1058 build_identity_conv (tree type, tree expr)
1062 c = alloc_conversion (ck_identity);
1069 /* Converting from EXPR to TYPE was ambiguous in the sense that there
1070 were multiple user-defined conversions to accomplish the job.
1071 Build a conversion that indicates that ambiguity. */
1074 build_ambiguous_conv (tree type, tree expr)
1078 c = alloc_conversion (ck_ambig);
1086 strip_top_quals (tree t)
1088 if (TREE_CODE (t) == ARRAY_TYPE)
1090 return cp_build_qualified_type (t, 0);
1093 /* Returns the standard conversion path (see [conv]) from type FROM to type
1094 TO, if any. For proper handling of null pointer constants, you must
1095 also pass the expression EXPR to convert from. If C_CAST_P is true,
1096 this conversion is coming from a C-style cast. */
1099 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
1100 int flags, tsubst_flags_t complain)
1102 enum tree_code fcode, tcode;
1104 bool fromref = false;
1107 to = non_reference (to);
1108 if (TREE_CODE (from) == REFERENCE_TYPE)
1111 from = TREE_TYPE (from);
1114 to = strip_top_quals (to);
1115 from = strip_top_quals (from);
1117 if (expr && type_unknown_p (expr))
1119 if (TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
1121 tsubst_flags_t tflags = tf_conv;
1122 expr = instantiate_type (to, expr, tflags);
1123 if (expr == error_mark_node)
1125 from = TREE_TYPE (expr);
1127 else if (TREE_CODE (to) == BOOLEAN_TYPE)
1129 /* Necessary for eg, TEMPLATE_ID_EXPRs (c++/50961). */
1130 expr = resolve_nondeduced_context (expr, complain);
1131 from = TREE_TYPE (expr);
1135 fcode = TREE_CODE (from);
1136 tcode = TREE_CODE (to);
1138 conv = build_identity_conv (from, expr);
1139 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
1141 from = type_decays_to (from);
1142 fcode = TREE_CODE (from);
1143 /* Tell convert_like_real that we're using the address. */
1144 conv->rvaluedness_matches_p = true;
1145 conv = build_conv (ck_lvalue, from, conv);
1147 /* Wrapping a ck_rvalue around a class prvalue (as a result of using
1148 obvalue_p) seems odd, since it's already a prvalue, but that's how we
1149 express the copy constructor call required by copy-initialization. */
1150 else if (fromref || (expr && obvalue_p (expr)))
1155 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
1158 from = strip_top_quals (bitfield_type);
1159 fcode = TREE_CODE (from);
1162 conv = build_conv (ck_rvalue, from, conv);
1163 if (flags & LOOKUP_PREFER_RVALUE)
1164 /* Tell convert_like_real to set LOOKUP_PREFER_RVALUE. */
1165 conv->rvaluedness_matches_p = true;
1168 /* Allow conversion between `__complex__' data types. */
1169 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
1171 /* The standard conversion sequence to convert FROM to TO is
1172 the standard conversion sequence to perform componentwise
1174 conversion *part_conv = standard_conversion
1175 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags,
1180 conv = build_conv (part_conv->kind, to, conv);
1181 conv->rank = part_conv->rank;
1189 if (same_type_p (from, to))
1191 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
1192 conv->type = qualified_to;
1197 A null pointer constant can be converted to a pointer type; ... A
1198 null pointer constant of integral type can be converted to an
1199 rvalue of type std::nullptr_t. */
1200 if ((tcode == POINTER_TYPE || TYPE_PTRMEM_P (to)
1201 || NULLPTR_TYPE_P (to))
1202 && ((expr && null_ptr_cst_p (expr))
1203 || NULLPTR_TYPE_P (from)))
1204 conv = build_conv (ck_std, to, conv);
1205 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
1206 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
1208 /* For backwards brain damage compatibility, allow interconversion of
1209 pointers and integers with a pedwarn. */
1210 conv = build_conv (ck_std, to, conv);
1213 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
1215 /* For backwards brain damage compatibility, allow interconversion of
1216 enums and integers with a pedwarn. */
1217 conv = build_conv (ck_std, to, conv);
1220 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1221 || (TYPE_PTRDATAMEM_P (to) && TYPE_PTRDATAMEM_P (from)))
1226 if (tcode == POINTER_TYPE)
1228 to_pointee = TREE_TYPE (to);
1229 from_pointee = TREE_TYPE (from);
1231 /* Since this is the target of a pointer, it can't have function
1232 qualifiers, so any TYPE_QUALS must be for attributes const or
1233 noreturn. Strip them. */
1234 if (TREE_CODE (to_pointee) == FUNCTION_TYPE
1235 && TYPE_QUALS (to_pointee))
1236 to_pointee = build_qualified_type (to_pointee, TYPE_UNQUALIFIED);
1237 if (TREE_CODE (from_pointee) == FUNCTION_TYPE
1238 && TYPE_QUALS (from_pointee))
1239 from_pointee = build_qualified_type (from_pointee, TYPE_UNQUALIFIED);
1243 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1244 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1247 if (tcode == POINTER_TYPE
1248 && same_type_ignoring_top_level_qualifiers_p (from_pointee,
1251 else if (VOID_TYPE_P (to_pointee)
1252 && !TYPE_PTRDATAMEM_P (from)
1253 && TREE_CODE (from_pointee) != FUNCTION_TYPE)
1255 tree nfrom = TREE_TYPE (from);
1256 /* Don't try to apply restrict to void. */
1257 int quals = cp_type_quals (nfrom) & ~TYPE_QUAL_RESTRICT;
1258 from_pointee = cp_build_qualified_type (void_type_node, quals);
1259 from = build_pointer_type (from_pointee);
1260 conv = build_conv (ck_ptr, from, conv);
1262 else if (TYPE_PTRDATAMEM_P (from))
1264 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1265 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1267 if (same_type_p (fbase, tbase))
1268 /* No base conversion needed. */;
1269 else if (DERIVED_FROM_P (fbase, tbase)
1270 && (same_type_ignoring_top_level_qualifiers_p
1271 (from_pointee, to_pointee)))
1273 from = build_ptrmem_type (tbase, from_pointee);
1274 conv = build_conv (ck_pmem, from, conv);
1279 else if (CLASS_TYPE_P (from_pointee)
1280 && CLASS_TYPE_P (to_pointee)
1283 An rvalue of type "pointer to cv D," where D is a
1284 class type, can be converted to an rvalue of type
1285 "pointer to cv B," where B is a base class (clause
1286 _class.derived_) of D. If B is an inaccessible
1287 (clause _class.access_) or ambiguous
1288 (_class.member.lookup_) base class of D, a program
1289 that necessitates this conversion is ill-formed.
1290 Therefore, we use DERIVED_FROM_P, and do not check
1291 access or uniqueness. */
1292 && DERIVED_FROM_P (to_pointee, from_pointee))
1295 = cp_build_qualified_type (to_pointee,
1296 cp_type_quals (from_pointee));
1297 from = build_pointer_type (from_pointee);
1298 conv = build_conv (ck_ptr, from, conv);
1299 conv->base_p = true;
1302 if (same_type_p (from, to))
1304 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1305 /* In a C-style cast, we ignore CV-qualification because we
1306 are allowed to perform a static_cast followed by a
1308 conv = build_conv (ck_qual, to, conv);
1309 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1310 conv = build_conv (ck_qual, to, conv);
1311 else if (expr && string_conv_p (to, expr, 0))
1312 /* converting from string constant to char *. */
1313 conv = build_conv (ck_qual, to, conv);
1314 else if (fnptr_conv_p (to, from))
1315 conv = build_conv (ck_fnptr, to, conv);
1316 /* Allow conversions among compatible ObjC pointer types (base
1317 conversions have been already handled above). */
1318 else if (c_dialect_objc ()
1319 && objc_compare_types (to, from, -4, NULL_TREE))
1320 conv = build_conv (ck_ptr, to, conv);
1321 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1323 conv = build_conv (ck_ptr, to, conv);
1331 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1333 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1334 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1335 tree fbase = class_of_this_parm (fromfn);
1336 tree tbase = class_of_this_parm (tofn);
1338 if (!DERIVED_FROM_P (fbase, tbase))
1341 tree fstat = static_fn_type (fromfn);
1342 tree tstat = static_fn_type (tofn);
1343 if (same_type_p (tstat, fstat)
1344 || fnptr_conv_p (tstat, fstat))
1349 if (!same_type_p (fbase, tbase))
1351 from = build_memfn_type (fstat,
1353 cp_type_quals (tbase),
1354 type_memfn_rqual (tofn));
1355 from = build_ptrmemfunc_type (build_pointer_type (from));
1356 conv = build_conv (ck_pmem, from, conv);
1357 conv->base_p = true;
1359 if (fnptr_conv_p (tstat, fstat))
1360 conv = build_conv (ck_fnptr, to, conv);
1362 else if (tcode == BOOLEAN_TYPE)
1366 A prvalue of arithmetic, unscoped enumeration, pointer, or pointer
1367 to member type can be converted to a prvalue of type bool. ...
1368 For direct-initialization (8.5 [dcl.init]), a prvalue of type
1369 std::nullptr_t can be converted to a prvalue of type bool; */
1370 if (ARITHMETIC_TYPE_P (from)
1371 || UNSCOPED_ENUM_P (from)
1372 || fcode == POINTER_TYPE
1373 || TYPE_PTRMEM_P (from)
1374 || NULLPTR_TYPE_P (from))
1376 conv = build_conv (ck_std, to, conv);
1377 if (fcode == POINTER_TYPE
1378 || TYPE_PTRDATAMEM_P (from)
1379 || (TYPE_PTRMEMFUNC_P (from)
1380 && conv->rank < cr_pbool)
1381 || NULLPTR_TYPE_P (from))
1382 conv->rank = cr_pbool;
1383 if (NULLPTR_TYPE_P (from) && (flags & LOOKUP_ONLYCONVERTING))
1390 /* We don't check for ENUMERAL_TYPE here because there are no standard
1391 conversions to enum type. */
1392 /* As an extension, allow conversion to complex type. */
1393 else if (ARITHMETIC_TYPE_P (to))
1395 if (! (INTEGRAL_CODE_P (fcode)
1396 || (fcode == REAL_TYPE && !(flags & LOOKUP_NO_NON_INTEGRAL)))
1397 || SCOPED_ENUM_P (from))
1400 /* If we're parsing an enum with no fixed underlying type, we're
1401 dealing with an incomplete type, which renders the conversion
1403 if (!COMPLETE_TYPE_P (from))
1406 conv = build_conv (ck_std, to, conv);
1408 /* Give this a better rank if it's a promotion. */
1409 if (same_type_p (to, type_promotes_to (from))
1410 && next_conversion (conv)->rank <= cr_promotion)
1411 conv->rank = cr_promotion;
1413 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1414 && vector_types_convertible_p (from, to, false))
1415 return build_conv (ck_std, to, conv);
1416 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1417 && is_properly_derived_from (from, to))
1419 if (conv->kind == ck_rvalue)
1420 conv = next_conversion (conv);
1421 conv = build_conv (ck_base, to, conv);
1422 /* The derived-to-base conversion indicates the initialization
1423 of a parameter with base type from an object of a derived
1424 type. A temporary object is created to hold the result of
1425 the conversion unless we're binding directly to a reference. */
1426 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1431 if (flags & LOOKUP_NO_NARROWING)
1432 conv->check_narrowing = true;
1437 /* Returns nonzero if T1 is reference-related to T2. */
1440 reference_related_p (tree t1, tree t2)
1442 if (t1 == error_mark_node || t2 == error_mark_node)
1445 t1 = TYPE_MAIN_VARIANT (t1);
1446 t2 = TYPE_MAIN_VARIANT (t2);
1450 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1451 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1453 return (same_type_p (t1, t2)
1454 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1455 && DERIVED_FROM_P (t1, t2)));
1458 /* Returns nonzero if T1 is reference-compatible with T2. */
1461 reference_compatible_p (tree t1, tree t2)
1465 "cv1 T1" is reference compatible with "cv2 T2" if
1466 * T1 is reference-related to T2 or
1467 * T2 is "noexcept function" and T1 is "function", where the
1468 function types are otherwise the same,
1469 and cv1 is the same cv-qualification as, or greater cv-qualification
1471 return ((reference_related_p (t1, t2)
1472 || fnptr_conv_p (t1, t2))
1473 && at_least_as_qualified_p (t1, t2));
1476 /* A reference of the indicated TYPE is being bound directly to the
1477 expression represented by the implicit conversion sequence CONV.
1478 Return a conversion sequence for this binding. */
1481 direct_reference_binding (tree type, conversion *conv)
1485 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1486 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1488 t = TREE_TYPE (type);
1490 if (conv->kind == ck_identity)
1491 /* Mark the identity conv as to not decay to rvalue. */
1492 conv->rvaluedness_matches_p = true;
1496 When a parameter of reference type binds directly
1497 (_dcl.init.ref_) to an argument expression, the implicit
1498 conversion sequence is the identity conversion, unless the
1499 argument expression has a type that is a derived class of the
1500 parameter type, in which case the implicit conversion sequence is
1501 a derived-to-base Conversion.
1503 If the parameter binds directly to the result of applying a
1504 conversion function to the argument expression, the implicit
1505 conversion sequence is a user-defined conversion sequence
1506 (_over.ics.user_), with the second standard conversion sequence
1507 either an identity conversion or, if the conversion function
1508 returns an entity of a type that is a derived class of the
1509 parameter type, a derived-to-base conversion. */
1510 if (is_properly_derived_from (conv->type, t))
1512 /* Represent the derived-to-base conversion. */
1513 conv = build_conv (ck_base, t, conv);
1514 /* We will actually be binding to the base-class subobject in
1515 the derived class, so we mark this conversion appropriately.
1516 That way, convert_like knows not to generate a temporary. */
1517 conv->need_temporary_p = false;
1520 return build_conv (ck_ref_bind, type, conv);
1523 /* Returns the conversion path from type FROM to reference type TO for
1524 purposes of reference binding. For lvalue binding, either pass a
1525 reference type to FROM or an lvalue expression to EXPR. If the
1526 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1527 the conversion returned. If C_CAST_P is true, this
1528 conversion is coming from a C-style cast. */
1531 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags,
1532 tsubst_flags_t complain)
1534 conversion *conv = NULL;
1535 tree to = TREE_TYPE (rto);
1540 cp_lvalue_kind gl_kind;
1543 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1545 expr = instantiate_type (to, expr, tf_none);
1546 if (expr == error_mark_node)
1548 from = TREE_TYPE (expr);
1551 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1553 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1554 /* DR 1288: Otherwise, if the initializer list has a single element
1555 of type E and ... [T's] referenced type is reference-related to E,
1556 the object or reference is initialized from that element... */
1557 if (CONSTRUCTOR_NELTS (expr) == 1)
1559 tree elt = CONSTRUCTOR_ELT (expr, 0)->value;
1560 if (error_operand_p (elt))
1562 tree etype = TREE_TYPE (elt);
1563 if (reference_related_p (to, etype))
1570 /* Otherwise, if T is a reference type, a prvalue temporary of the
1571 type referenced by T is copy-list-initialized or
1572 direct-list-initialized, depending on the kind of initialization
1573 for the reference, and the reference is bound to that temporary. */
1574 conv = implicit_conversion (to, from, expr, c_cast_p,
1575 flags|LOOKUP_NO_TEMP_BIND, complain);
1579 if (TREE_CODE (from) == REFERENCE_TYPE)
1581 from = TREE_TYPE (from);
1582 if (!TYPE_REF_IS_RVALUE (rfrom)
1583 || TREE_CODE (from) == FUNCTION_TYPE)
1584 gl_kind = clk_ordinary;
1586 gl_kind = clk_rvalueref;
1589 gl_kind = lvalue_kind (expr);
1590 else if (CLASS_TYPE_P (from)
1591 || TREE_CODE (from) == ARRAY_TYPE)
1592 gl_kind = clk_class;
1596 /* Don't allow a class prvalue when LOOKUP_NO_TEMP_BIND. */
1597 if ((flags & LOOKUP_NO_TEMP_BIND)
1598 && (gl_kind & clk_class))
1601 /* Same mask as real_lvalue_p. */
1602 is_lvalue = gl_kind && !(gl_kind & (clk_rvalueref|clk_class));
1605 if ((gl_kind & clk_bitfield) != 0)
1606 tfrom = unlowered_expr_type (expr);
1608 /* Figure out whether or not the types are reference-related and
1609 reference compatible. We have to do this after stripping
1610 references from FROM. */
1611 related_p = reference_related_p (to, tfrom);
1612 /* If this is a C cast, first convert to an appropriately qualified
1613 type, so that we can later do a const_cast to the desired type. */
1614 if (related_p && c_cast_p
1615 && !at_least_as_qualified_p (to, tfrom))
1616 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1617 compatible_p = reference_compatible_p (to, tfrom);
1619 /* Directly bind reference when target expression's type is compatible with
1620 the reference and expression is an lvalue. In DR391, the wording in
1621 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1622 const and rvalue references to rvalues of compatible class type.
1623 We should also do direct bindings for non-class xvalues. */
1624 if ((related_p || compatible_p) && gl_kind)
1628 If the initializer expression
1630 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1631 is reference-compatible with "cv2 T2,"
1633 the reference is bound directly to the initializer expression
1637 If the initializer expression is an rvalue, with T2 a class type,
1638 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1639 is bound to the object represented by the rvalue or to a sub-object
1640 within that object. */
1642 conv = build_identity_conv (tfrom, expr);
1643 conv = direct_reference_binding (rto, conv);
1645 if (TREE_CODE (rfrom) == REFERENCE_TYPE)
1646 /* Handle rvalue reference to function properly. */
1647 conv->rvaluedness_matches_p
1648 = (TYPE_REF_IS_RVALUE (rto) == TYPE_REF_IS_RVALUE (rfrom));
1650 conv->rvaluedness_matches_p
1651 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1653 if ((gl_kind & clk_bitfield) != 0
1654 || ((gl_kind & clk_packed) != 0 && !TYPE_PACKED (to)))
1655 /* For the purposes of overload resolution, we ignore the fact
1656 this expression is a bitfield or packed field. (In particular,
1657 [over.ics.ref] says specifically that a function with a
1658 non-const reference parameter is viable even if the
1659 argument is a bitfield.)
1661 However, when we actually call the function we must create
1662 a temporary to which to bind the reference. If the
1663 reference is volatile, or isn't const, then we cannot make
1664 a temporary, so we just issue an error when the conversion
1666 conv->need_temporary_p = true;
1668 /* Don't allow binding of lvalues (other than function lvalues) to
1669 rvalue references. */
1670 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1671 && TREE_CODE (to) != FUNCTION_TYPE)
1674 /* Nor the reverse. */
1675 if (!is_lvalue && !TYPE_REF_IS_RVALUE (rto)
1676 && (!CP_TYPE_CONST_NON_VOLATILE_P (to)
1677 || (flags & LOOKUP_NO_RVAL_BIND))
1678 && TREE_CODE (to) != FUNCTION_TYPE)
1686 /* [class.conv.fct] A conversion function is never used to convert a
1687 (possibly cv-qualified) object to the (possibly cv-qualified) same
1688 object type (or a reference to it), to a (possibly cv-qualified) base
1689 class of that type (or a reference to it).... */
1690 else if (CLASS_TYPE_P (from) && !related_p
1691 && !(flags & LOOKUP_NO_CONVERSION))
1695 If the initializer expression
1697 -- has a class type (i.e., T2 is a class type) can be
1698 implicitly converted to an lvalue of type "cv3 T3," where
1699 "cv1 T1" is reference-compatible with "cv3 T3". (this
1700 conversion is selected by enumerating the applicable
1701 conversion functions (_over.match.ref_) and choosing the
1702 best one through overload resolution. (_over.match_).
1704 the reference is bound to the lvalue result of the conversion
1705 in the second case. */
1706 z_candidate *cand = build_user_type_conversion_1 (rto, expr, flags,
1709 return cand->second_conv;
1712 /* From this point on, we conceptually need temporaries, even if we
1713 elide them. Only the cases above are "direct bindings". */
1714 if (flags & LOOKUP_NO_TEMP_BIND)
1719 When a parameter of reference type is not bound directly to an
1720 argument expression, the conversion sequence is the one required
1721 to convert the argument expression to the underlying type of the
1722 reference according to _over.best.ics_. Conceptually, this
1723 conversion sequence corresponds to copy-initializing a temporary
1724 of the underlying type with the argument expression. Any
1725 difference in top-level cv-qualification is subsumed by the
1726 initialization itself and does not constitute a conversion. */
1730 Otherwise, the reference shall be an lvalue reference to a
1731 non-volatile const type, or the reference shall be an rvalue
1734 We try below to treat this as a bad conversion to improve diagnostics,
1735 but if TO is an incomplete class, we need to reject this conversion
1736 now to avoid unnecessary instantiation. */
1737 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto)
1738 && !COMPLETE_TYPE_P (to))
1741 /* We're generating a temporary now, but don't bind any more in the
1742 conversion (specifically, don't slice the temporary returned by a
1743 conversion operator). */
1744 flags |= LOOKUP_NO_TEMP_BIND;
1746 /* Core issue 899: When [copy-]initializing a temporary to be bound
1747 to the first parameter of a copy constructor (12.8) called with
1748 a single argument in the context of direct-initialization,
1749 explicit conversion functions are also considered.
1751 So don't set LOOKUP_ONLYCONVERTING in that case. */
1752 if (!(flags & LOOKUP_COPY_PARM))
1753 flags |= LOOKUP_ONLYCONVERTING;
1756 conv = implicit_conversion (to, from, expr, c_cast_p,
1761 if (conv->user_conv_p)
1763 /* If initializing the temporary used a conversion function,
1764 recalculate the second conversion sequence. */
1765 for (conversion *t = conv; t; t = next_conversion (t))
1766 if (t->kind == ck_user
1767 && DECL_CONV_FN_P (t->cand->fn))
1769 tree ftype = TREE_TYPE (TREE_TYPE (t->cand->fn));
1770 int sflags = (flags|LOOKUP_NO_CONVERSION)&~LOOKUP_NO_TEMP_BIND;
1771 conversion *new_second
1772 = reference_binding (rto, ftype, NULL_TREE, c_cast_p,
1776 return merge_conversion_sequences (t, new_second);
1780 conv = build_conv (ck_ref_bind, rto, conv);
1781 /* This reference binding, unlike those above, requires the
1782 creation of a temporary. */
1783 conv->need_temporary_p = true;
1784 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1788 Otherwise, the reference shall be an lvalue reference to a
1789 non-volatile const type, or the reference shall be an rvalue
1791 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1796 Otherwise, a temporary of type "cv1 T1" is created and
1797 initialized from the initializer expression using the rules for a
1798 non-reference copy initialization. If T1 is reference-related to
1799 T2, cv1 must be the same cv-qualification as, or greater
1800 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1801 if (related_p && !at_least_as_qualified_p (to, from))
1807 /* Returns the implicit conversion sequence (see [over.ics]) from type
1808 FROM to type TO. The optional expression EXPR may affect the
1809 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1810 true, this conversion is coming from a C-style cast. */
1813 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1814 int flags, tsubst_flags_t complain)
1818 if (from == error_mark_node || to == error_mark_node
1819 || expr == error_mark_node)
1822 /* Other flags only apply to the primary function in overload
1823 resolution, or after we've chosen one. */
1824 flags &= (LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION|LOOKUP_COPY_PARM
1825 |LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND|LOOKUP_PREFER_RVALUE
1826 |LOOKUP_NO_NARROWING|LOOKUP_PROTECT|LOOKUP_NO_NON_INTEGRAL);
1828 /* FIXME: actually we don't want warnings either, but we can't just
1829 have 'complain &= ~(tf_warning|tf_error)' because it would cause
1830 the regression of, eg, g++.old-deja/g++.benjamin/16077.C.
1831 We really ought not to issue that warning until we've committed
1832 to that conversion. */
1833 complain &= ~tf_error;
1835 /* Call reshape_init early to remove redundant braces. */
1836 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr)
1837 && CLASS_TYPE_P (to)
1838 && COMPLETE_TYPE_P (complete_type (to))
1839 && !CLASSTYPE_NON_AGGREGATE (to))
1841 expr = reshape_init (to, expr, complain);
1842 if (expr == error_mark_node)
1844 from = TREE_TYPE (expr);
1847 if (TREE_CODE (to) == REFERENCE_TYPE)
1848 conv = reference_binding (to, from, expr, c_cast_p, flags, complain);
1850 conv = standard_conversion (to, from, expr, c_cast_p, flags, complain);
1855 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1857 if (is_std_init_list (to))
1858 return build_list_conv (to, expr, flags, complain);
1860 /* As an extension, allow list-initialization of _Complex. */
1861 if (TREE_CODE (to) == COMPLEX_TYPE)
1863 conv = build_complex_conv (to, expr, flags, complain);
1868 /* Allow conversion from an initializer-list with one element to a
1870 if (SCALAR_TYPE_P (to))
1872 int nelts = CONSTRUCTOR_NELTS (expr);
1876 elt = build_value_init (to, tf_none);
1877 else if (nelts == 1)
1878 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1880 elt = error_mark_node;
1882 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1883 c_cast_p, flags, complain);
1886 conv->check_narrowing = true;
1887 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1888 /* Too many levels of braces, i.e. '{{1}}'. */
1893 else if (TREE_CODE (to) == ARRAY_TYPE)
1894 return build_array_conv (to, expr, flags, complain);
1897 if (expr != NULL_TREE
1898 && (MAYBE_CLASS_TYPE_P (from)
1899 || MAYBE_CLASS_TYPE_P (to))
1900 && (flags & LOOKUP_NO_CONVERSION) == 0)
1902 struct z_candidate *cand;
1904 if (CLASS_TYPE_P (to)
1905 && BRACE_ENCLOSED_INITIALIZER_P (expr)
1906 && !CLASSTYPE_NON_AGGREGATE (complete_type (to)))
1907 return build_aggr_conv (to, expr, flags, complain);
1909 cand = build_user_type_conversion_1 (to, expr, flags, complain);
1912 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
1913 && CONSTRUCTOR_NELTS (expr) == 1
1914 && !is_list_ctor (cand->fn))
1916 /* "If C is not an initializer-list constructor and the
1917 initializer list has a single element of type cv U, where U is
1918 X or a class derived from X, the implicit conversion sequence
1919 has Exact Match rank if U is X, or Conversion rank if U is
1921 tree elt = CONSTRUCTOR_ELT (expr, 0)->value;
1922 tree elttype = TREE_TYPE (elt);
1923 if (reference_related_p (to, elttype))
1924 return implicit_conversion (to, elttype, elt,
1925 c_cast_p, flags, complain);
1927 conv = cand->second_conv;
1930 /* We used to try to bind a reference to a temporary here, but that
1931 is now handled after the recursive call to this function at the end
1932 of reference_binding. */
1939 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1940 functions. ARGS will not be changed until a single candidate is
1943 static struct z_candidate *
1944 add_candidate (struct z_candidate **candidates,
1945 tree fn, tree first_arg, const vec<tree, va_gc> *args,
1946 size_t num_convs, conversion **convs,
1947 tree access_path, tree conversion_path,
1948 int viable, struct rejection_reason *reason,
1951 struct z_candidate *cand = (struct z_candidate *)
1952 conversion_obstack_alloc (sizeof (struct z_candidate));
1955 cand->first_arg = first_arg;
1957 cand->convs = convs;
1958 cand->num_convs = num_convs;
1959 cand->access_path = access_path;
1960 cand->conversion_path = conversion_path;
1961 cand->viable = viable;
1962 cand->reason = reason;
1963 cand->next = *candidates;
1964 cand->flags = flags;
1970 /* Return the number of remaining arguments in the parameter list
1971 beginning with ARG. */
1974 remaining_arguments (tree arg)
1978 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1979 arg = TREE_CHAIN (arg))
1985 /* Create an overload candidate for the function or method FN called
1986 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1987 FLAGS is passed on to implicit_conversion.
1989 This does not change ARGS.
1991 CTYPE, if non-NULL, is the type we want to pretend this function
1992 comes from for purposes of overload resolution. */
1994 static struct z_candidate *
1995 add_function_candidate (struct z_candidate **candidates,
1996 tree fn, tree ctype, tree first_arg,
1997 const vec<tree, va_gc> *args, tree access_path,
1998 tree conversion_path, int flags,
1999 tsubst_flags_t complain)
2001 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
2005 tree orig_first_arg = first_arg;
2008 struct rejection_reason *reason = NULL;
2010 /* At this point we should not see any functions which haven't been
2011 explicitly declared, except for friend functions which will have
2012 been found using argument dependent lookup. */
2013 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
2015 /* The `this', `in_chrg' and VTT arguments to constructors are not
2016 considered in overload resolution. */
2017 if (DECL_CONSTRUCTOR_P (fn))
2019 if (ctor_omit_inherited_parms (fn))
2020 /* Bring back parameters omitted from an inherited ctor. */
2021 parmlist = FUNCTION_FIRST_USER_PARMTYPE (DECL_ORIGIN (fn));
2023 parmlist = skip_artificial_parms_for (fn, parmlist);
2024 skip = num_artificial_parms_for (fn);
2025 if (skip > 0 && first_arg != NULL_TREE)
2028 first_arg = NULL_TREE;
2034 len = vec_safe_length (args) - skip + (first_arg != NULL_TREE ? 1 : 0);
2035 convs = alloc_conversions (len);
2037 /* 13.3.2 - Viable functions [over.match.viable]
2038 First, to be a viable function, a candidate function shall have enough
2039 parameters to agree in number with the arguments in the list.
2041 We need to check this first; otherwise, checking the ICSes might cause
2042 us to produce an ill-formed template instantiation. */
2044 parmnode = parmlist;
2045 for (i = 0; i < len; ++i)
2047 if (parmnode == NULL_TREE || parmnode == void_list_node)
2049 parmnode = TREE_CHAIN (parmnode);
2052 if ((i < len && parmnode)
2053 || !sufficient_parms_p (parmnode))
2055 int remaining = remaining_arguments (parmnode);
2057 reason = arity_rejection (first_arg, i + remaining, len);
2060 /* An inherited constructor (12.6.3 [class.inhctor.init]) that has a first
2061 parameter of type "reference to cv C" (including such a constructor
2062 instantiated from a template) is excluded from the set of candidate
2063 functions when used to construct an object of type D with an argument list
2064 containing a single argument if C is reference-related to D. */
2065 if (viable && len == 1 && parmlist && DECL_CONSTRUCTOR_P (fn)
2066 && flag_new_inheriting_ctors
2067 && DECL_INHERITED_CTOR (fn))
2069 tree ptype = non_reference (TREE_VALUE (parmlist));
2070 tree dtype = DECL_CONTEXT (fn);
2071 tree btype = DECL_INHERITED_CTOR_BASE (fn);
2072 if (reference_related_p (ptype, dtype)
2073 && reference_related_p (btype, ptype))
2076 reason = inherited_ctor_rejection ();
2080 /* Second, for a function to be viable, its constraints must be
2082 if (flag_concepts && viable
2083 && !constraints_satisfied_p (fn))
2085 reason = constraint_failure (fn);
2089 /* When looking for a function from a subobject from an implicit
2090 copy/move constructor/operator=, don't consider anything that takes (a
2091 reference to) an unrelated type. See c++/44909 and core 1092. */
2092 if (viable && parmlist && (flags & LOOKUP_DEFAULTED))
2094 if (DECL_CONSTRUCTOR_P (fn))
2096 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
2097 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR))
2103 parmnode = chain_index (i-1, parmlist);
2104 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
2109 /* This only applies at the top level. */
2110 flags &= ~LOOKUP_DEFAULTED;
2116 /* Third, for F to be a viable function, there shall exist for each
2117 argument an implicit conversion sequence that converts that argument
2118 to the corresponding parameter of F. */
2120 parmnode = parmlist;
2122 for (i = 0; i < len; ++i)
2124 tree argtype, to_type;
2129 if (parmnode == void_list_node)
2132 if (i == 0 && first_arg != NULL_TREE)
2135 arg = CONST_CAST_TREE (
2136 (*args)[i + skip - (first_arg != NULL_TREE ? 1 : 0)]);
2137 argtype = lvalue_type (arg);
2139 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
2140 && ! DECL_CONSTRUCTOR_P (fn));
2144 tree parmtype = TREE_VALUE (parmnode);
2147 parmnode = TREE_CHAIN (parmnode);
2149 /* The type of the implicit object parameter ('this') for
2150 overload resolution is not always the same as for the
2151 function itself; conversion functions are considered to
2152 be members of the class being converted, and functions
2153 introduced by a using-declaration are considered to be
2154 members of the class that uses them.
2156 Since build_over_call ignores the ICS for the `this'
2157 parameter, we can just change the parm type. */
2158 if (ctype && is_this)
2160 parmtype = cp_build_qualified_type
2161 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
2162 if (FUNCTION_REF_QUALIFIED (TREE_TYPE (fn)))
2164 /* If the function has a ref-qualifier, the implicit
2165 object parameter has reference type. */
2166 bool rv = FUNCTION_RVALUE_QUALIFIED (TREE_TYPE (fn));
2167 parmtype = cp_build_reference_type (parmtype, rv);
2168 /* The special handling of 'this' conversions in compare_ics
2169 does not apply if there is a ref-qualifier. */
2174 parmtype = build_pointer_type (parmtype);
2175 /* We don't use build_this here because we don't want to
2176 capture the object argument until we've chosen a
2177 non-static member function. */
2178 arg = build_address (arg);
2179 argtype = lvalue_type (arg);
2183 /* Core issue 899: When [copy-]initializing a temporary to be bound
2184 to the first parameter of a copy constructor (12.8) called with
2185 a single argument in the context of direct-initialization,
2186 explicit conversion functions are also considered.
2188 So set LOOKUP_COPY_PARM to let reference_binding know that
2189 it's being called in that context. We generalize the above
2190 to handle move constructors and template constructors as well;
2191 the standardese should soon be updated similarly. */
2192 if (ctype && i == 0 && (len-skip == 1)
2193 && DECL_CONSTRUCTOR_P (fn)
2194 && parmtype != error_mark_node
2195 && (same_type_ignoring_top_level_qualifiers_p
2196 (non_reference (parmtype), ctype)))
2198 if (!(flags & LOOKUP_ONLYCONVERTING))
2199 lflags |= LOOKUP_COPY_PARM;
2200 /* We allow user-defined conversions within init-lists, but
2201 don't list-initialize the copy parm, as that would mean
2202 using two levels of braces for the same type. */
2203 if ((flags & LOOKUP_LIST_INIT_CTOR)
2204 && BRACE_ENCLOSED_INITIALIZER_P (arg))
2205 lflags |= LOOKUP_NO_CONVERSION;
2208 lflags |= LOOKUP_ONLYCONVERTING;
2210 t = implicit_conversion (parmtype, argtype, arg,
2211 /*c_cast_p=*/false, lflags, complain);
2216 t = build_identity_conv (argtype, arg);
2217 t->ellipsis_p = true;
2228 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
2235 reason = bad_arg_conversion_rejection (first_arg, i, arg, to_type);
2240 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
2241 access_path, conversion_path, viable, reason, flags);
2244 /* Create an overload candidate for the conversion function FN which will
2245 be invoked for expression OBJ, producing a pointer-to-function which
2246 will in turn be called with the argument list FIRST_ARG/ARGLIST,
2247 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
2248 passed on to implicit_conversion.
2250 Actually, we don't really care about FN; we care about the type it
2251 converts to. There may be multiple conversion functions that will
2252 convert to that type, and we rely on build_user_type_conversion_1 to
2253 choose the best one; so when we create our candidate, we record the type
2254 instead of the function. */
2256 static struct z_candidate *
2257 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
2258 const vec<tree, va_gc> *arglist,
2259 tree access_path, tree conversion_path,
2260 tsubst_flags_t complain)
2262 tree totype = TREE_TYPE (TREE_TYPE (fn));
2263 int i, len, viable, flags;
2264 tree parmlist, parmnode;
2266 struct rejection_reason *reason;
2268 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
2269 parmlist = TREE_TYPE (parmlist);
2270 parmlist = TYPE_ARG_TYPES (parmlist);
2272 len = vec_safe_length (arglist) + 1;
2273 convs = alloc_conversions (len);
2274 parmnode = parmlist;
2276 flags = LOOKUP_IMPLICIT;
2279 /* Don't bother looking up the same type twice. */
2280 if (*candidates && (*candidates)->fn == totype)
2283 for (i = 0; i < len; ++i)
2285 tree arg, argtype, convert_type = NULL_TREE;
2291 arg = (*arglist)[i - 1];
2292 argtype = lvalue_type (arg);
2296 t = build_identity_conv (argtype, NULL_TREE);
2297 t = build_conv (ck_user, totype, t);
2298 /* Leave the 'cand' field null; we'll figure out the conversion in
2299 convert_like_real if this candidate is chosen. */
2300 convert_type = totype;
2302 else if (parmnode == void_list_node)
2306 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2307 /*c_cast_p=*/false, flags, complain);
2308 convert_type = TREE_VALUE (parmnode);
2312 t = build_identity_conv (argtype, arg);
2313 t->ellipsis_p = true;
2314 convert_type = argtype;
2324 reason = bad_arg_conversion_rejection (NULL_TREE, i, arg, convert_type);
2331 parmnode = TREE_CHAIN (parmnode);
2335 || ! sufficient_parms_p (parmnode))
2337 int remaining = remaining_arguments (parmnode);
2339 reason = arity_rejection (NULL_TREE, i + remaining, len);
2342 return add_candidate (candidates, totype, obj, arglist, len, convs,
2343 access_path, conversion_path, viable, reason, flags);
2347 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2348 tree type1, tree type2, tree *args, tree *argtypes,
2349 int flags, tsubst_flags_t complain)
2356 struct rejection_reason *reason = NULL;
2361 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2362 convs = alloc_conversions (num_convs);
2364 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2365 conversion ops are allowed. We handle that here by just checking for
2366 boolean_type_node because other operators don't ask for it. COND_EXPR
2367 also does contextual conversion to bool for the first operand, but we
2368 handle that in build_conditional_expr, and type1 here is operand 2. */
2369 if (type1 != boolean_type_node)
2370 flags |= LOOKUP_ONLYCONVERTING;
2372 for (i = 0; i < 2; ++i)
2377 t = implicit_conversion (types[i], argtypes[i], args[i],
2378 /*c_cast_p=*/false, flags, complain);
2382 /* We need something for printing the candidate. */
2383 t = build_identity_conv (types[i], NULL_TREE);
2384 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i],
2390 reason = bad_arg_conversion_rejection (NULL_TREE, i, args[i],
2396 /* For COND_EXPR we rearranged the arguments; undo that now. */
2399 convs[2] = convs[1];
2400 convs[1] = convs[0];
2401 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2402 /*c_cast_p=*/false, flags,
2409 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2414 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2416 /*access_path=*/NULL_TREE,
2417 /*conversion_path=*/NULL_TREE,
2418 viable, reason, flags);
2422 is_complete (tree t)
2424 return COMPLETE_TYPE_P (complete_type (t));
2427 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2430 promoted_arithmetic_type_p (tree type)
2434 In this section, the term promoted integral type is used to refer
2435 to those integral types which are preserved by integral promotion
2436 (including e.g. int and long but excluding e.g. char).
2437 Similarly, the term promoted arithmetic type refers to promoted
2438 integral types plus floating types. */
2439 return ((CP_INTEGRAL_TYPE_P (type)
2440 && same_type_p (type_promotes_to (type), type))
2441 || TREE_CODE (type) == REAL_TYPE);
2444 /* Create any builtin operator overload candidates for the operator in
2445 question given the converted operand types TYPE1 and TYPE2. The other
2446 args are passed through from add_builtin_candidates to
2447 build_builtin_candidate.
2449 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2450 If CODE is requires candidates operands of the same type of the kind
2451 of which TYPE1 and TYPE2 are, we add both candidates
2452 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2455 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2456 enum tree_code code2, tree fnname, tree type1,
2457 tree type2, tree *args, tree *argtypes, int flags,
2458 tsubst_flags_t complain)
2462 case POSTINCREMENT_EXPR:
2463 case POSTDECREMENT_EXPR:
2464 args[1] = integer_zero_node;
2465 type2 = integer_type_node;
2474 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2475 and VQ is either volatile or empty, there exist candidate operator
2476 functions of the form
2477 VQ T& operator++(VQ T&);
2478 T operator++(VQ T&, int);
2479 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2480 type other than bool, and VQ is either volatile or empty, there exist
2481 candidate operator functions of the form
2482 VQ T& operator--(VQ T&);
2483 T operator--(VQ T&, int);
2484 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2485 complete object type, and VQ is either volatile or empty, there exist
2486 candidate operator functions of the form
2487 T*VQ& operator++(T*VQ&);
2488 T*VQ& operator--(T*VQ&);
2489 T* operator++(T*VQ&, int);
2490 T* operator--(T*VQ&, int); */
2492 case POSTDECREMENT_EXPR:
2493 case PREDECREMENT_EXPR:
2494 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2497 case POSTINCREMENT_EXPR:
2498 case PREINCREMENT_EXPR:
2499 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2501 type1 = build_reference_type (type1);
2506 /* 7 For every cv-qualified or cv-unqualified object type T, there
2507 exist candidate operator functions of the form
2511 8 For every function type T, there exist candidate operator functions of
2513 T& operator*(T*); */
2516 if (TYPE_PTR_P (type1)
2517 && (TYPE_PTROB_P (type1)
2518 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2522 /* 9 For every type T, there exist candidate operator functions of the form
2525 10For every promoted arithmetic type T, there exist candidate operator
2526 functions of the form
2530 case UNARY_PLUS_EXPR: /* unary + */
2531 if (TYPE_PTR_P (type1))
2535 if (ARITHMETIC_TYPE_P (type1))
2539 /* 11For every promoted integral type T, there exist candidate operator
2540 functions of the form
2544 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2548 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2549 is the same type as C2 or is a derived class of C2, T is a complete
2550 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2551 there exist candidate operator functions of the form
2552 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2553 where CV12 is the union of CV1 and CV2. */
2556 if (TYPE_PTR_P (type1) && TYPE_PTRMEM_P (type2))
2558 tree c1 = TREE_TYPE (type1);
2559 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2561 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2562 && (TYPE_PTRMEMFUNC_P (type2)
2563 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2568 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2569 didate operator functions of the form
2574 bool operator<(L, R);
2575 bool operator>(L, R);
2576 bool operator<=(L, R);
2577 bool operator>=(L, R);
2578 bool operator==(L, R);
2579 bool operator!=(L, R);
2580 where LR is the result of the usual arithmetic conversions between
2583 14For every pair of types T and I, where T is a cv-qualified or cv-
2584 unqualified complete object type and I is a promoted integral type,
2585 there exist candidate operator functions of the form
2586 T* operator+(T*, I);
2587 T& operator[](T*, I);
2588 T* operator-(T*, I);
2589 T* operator+(I, T*);
2590 T& operator[](I, T*);
2592 15For every T, where T is a pointer to complete object type, there exist
2593 candidate operator functions of the form112)
2594 ptrdiff_t operator-(T, T);
2596 16For every pointer or enumeration type T, there exist candidate operator
2597 functions of the form
2598 bool operator<(T, T);
2599 bool operator>(T, T);
2600 bool operator<=(T, T);
2601 bool operator>=(T, T);
2602 bool operator==(T, T);
2603 bool operator!=(T, T);
2605 17For every pointer to member type T, there exist candidate operator
2606 functions of the form
2607 bool operator==(T, T);
2608 bool operator!=(T, T); */
2611 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2613 if (TYPE_PTROB_P (type1)
2614 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2616 type2 = ptrdiff_type_node;
2621 case TRUNC_DIV_EXPR:
2622 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2628 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2629 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2)))
2631 if (TYPE_PTRMEM_P (type1) && null_ptr_cst_p (args[1]))
2636 if (TYPE_PTRMEM_P (type2) && null_ptr_cst_p (args[0]))
2648 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2650 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2652 if (TREE_CODE (type1) == ENUMERAL_TYPE
2653 && TREE_CODE (type2) == ENUMERAL_TYPE)
2655 if (TYPE_PTR_P (type1)
2656 && null_ptr_cst_p (args[1]))
2661 if (null_ptr_cst_p (args[0])
2662 && TYPE_PTR_P (type2))
2670 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2674 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2676 type1 = ptrdiff_type_node;
2679 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2681 type2 = ptrdiff_type_node;
2686 /* 18For every pair of promoted integral types L and R, there exist candi-
2687 date operator functions of the form
2694 where LR is the result of the usual arithmetic conversions between
2697 case TRUNC_MOD_EXPR:
2703 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2707 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2708 type, VQ is either volatile or empty, and R is a promoted arithmetic
2709 type, there exist candidate operator functions of the form
2710 VQ L& operator=(VQ L&, R);
2711 VQ L& operator*=(VQ L&, R);
2712 VQ L& operator/=(VQ L&, R);
2713 VQ L& operator+=(VQ L&, R);
2714 VQ L& operator-=(VQ L&, R);
2716 20For every pair T, VQ), where T is any type and VQ is either volatile
2717 or empty, there exist candidate operator functions of the form
2718 T*VQ& operator=(T*VQ&, T*);
2720 21For every pair T, VQ), where T is a pointer to member type and VQ is
2721 either volatile or empty, there exist candidate operator functions of
2723 VQ T& operator=(VQ T&, T);
2725 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2726 unqualified complete object type, VQ is either volatile or empty, and
2727 I is a promoted integral type, there exist candidate operator func-
2729 T*VQ& operator+=(T*VQ&, I);
2730 T*VQ& operator-=(T*VQ&, I);
2732 23For every triple L, VQ, R), where L is an integral or enumeration
2733 type, VQ is either volatile or empty, and R is a promoted integral
2734 type, there exist candidate operator functions of the form
2736 VQ L& operator%=(VQ L&, R);
2737 VQ L& operator<<=(VQ L&, R);
2738 VQ L& operator>>=(VQ L&, R);
2739 VQ L& operator&=(VQ L&, R);
2740 VQ L& operator^=(VQ L&, R);
2741 VQ L& operator|=(VQ L&, R); */
2748 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2750 type2 = ptrdiff_type_node;
2755 case TRUNC_DIV_EXPR:
2756 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2760 case TRUNC_MOD_EXPR:
2766 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2771 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2773 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2774 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2775 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2776 || ((TYPE_PTRMEMFUNC_P (type1)
2777 || TYPE_PTR_P (type1))
2778 && null_ptr_cst_p (args[1])))
2788 type1 = build_reference_type (type1);
2794 For every pair of promoted arithmetic types L and R, there
2795 exist candidate operator functions of the form
2797 LR operator?(bool, L, R);
2799 where LR is the result of the usual arithmetic conversions
2800 between types L and R.
2802 For every type T, where T is a pointer or pointer-to-member
2803 type, there exist candidate operator functions of the form T
2804 operator?(bool, T, T); */
2806 if (promoted_arithmetic_type_p (type1)
2807 && promoted_arithmetic_type_p (type2))
2811 /* Otherwise, the types should be pointers. */
2812 if (!TYPE_PTR_OR_PTRMEM_P (type1) || !TYPE_PTR_OR_PTRMEM_P (type2))
2815 /* We don't check that the two types are the same; the logic
2816 below will actually create two candidates; one in which both
2817 parameter types are TYPE1, and one in which both parameter
2823 if (ARITHMETIC_TYPE_P (type1))
2831 /* Make sure we don't create builtin candidates with dependent types. */
2832 bool u1 = uses_template_parms (type1);
2833 bool u2 = type2 ? uses_template_parms (type2) : false;
2836 /* Try to recover if one of the types is non-dependent. But if
2837 there's only one type, there's nothing we can do. */
2840 /* And we lose if both are dependent. */
2843 /* Or if they have different forms. */
2844 if (TREE_CODE (type1) != TREE_CODE (type2))
2853 /* If we're dealing with two pointer types or two enumeral types,
2854 we need candidates for both of them. */
2855 if (type2 && !same_type_p (type1, type2)
2856 && TREE_CODE (type1) == TREE_CODE (type2)
2857 && (TREE_CODE (type1) == REFERENCE_TYPE
2858 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2859 || (TYPE_PTRDATAMEM_P (type1) && TYPE_PTRDATAMEM_P (type2))
2860 || TYPE_PTRMEMFUNC_P (type1)
2861 || MAYBE_CLASS_TYPE_P (type1)
2862 || TREE_CODE (type1) == ENUMERAL_TYPE))
2864 if (TYPE_PTR_OR_PTRMEM_P (type1))
2866 tree cptype = composite_pointer_type (type1, type2,
2871 if (cptype != error_mark_node)
2873 build_builtin_candidate
2874 (candidates, fnname, cptype, cptype, args, argtypes,
2880 build_builtin_candidate
2881 (candidates, fnname, type1, type1, args, argtypes, flags, complain);
2882 build_builtin_candidate
2883 (candidates, fnname, type2, type2, args, argtypes, flags, complain);
2887 build_builtin_candidate
2888 (candidates, fnname, type1, type2, args, argtypes, flags, complain);
2892 type_decays_to (tree type)
2894 if (TREE_CODE (type) == ARRAY_TYPE)
2895 return build_pointer_type (TREE_TYPE (type));
2896 if (TREE_CODE (type) == FUNCTION_TYPE)
2897 return build_pointer_type (type);
2901 /* There are three conditions of builtin candidates:
2903 1) bool-taking candidates. These are the same regardless of the input.
2904 2) pointer-pair taking candidates. These are generated for each type
2905 one of the input types converts to.
2906 3) arithmetic candidates. According to the standard, we should generate
2907 all of these, but I'm trying not to...
2909 Here we generate a superset of the possible candidates for this particular
2910 case. That is a subset of the full set the standard defines, plus some
2911 other cases which the standard disallows. add_builtin_candidate will
2912 filter out the invalid set. */
2915 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2916 enum tree_code code2, tree fnname, tree *args,
2917 int flags, tsubst_flags_t complain)
2921 tree type, argtypes[3], t;
2922 /* TYPES[i] is the set of possible builtin-operator parameter types
2923 we will consider for the Ith argument. */
2924 vec<tree, va_gc> *types[2];
2927 for (i = 0; i < 3; ++i)
2930 argtypes[i] = unlowered_expr_type (args[i]);
2932 argtypes[i] = NULL_TREE;
2937 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2938 and VQ is either volatile or empty, there exist candidate operator
2939 functions of the form
2940 VQ T& operator++(VQ T&); */
2942 case POSTINCREMENT_EXPR:
2943 case PREINCREMENT_EXPR:
2944 case POSTDECREMENT_EXPR:
2945 case PREDECREMENT_EXPR:
2950 /* 24There also exist candidate operator functions of the form
2951 bool operator!(bool);
2952 bool operator&&(bool, bool);
2953 bool operator||(bool, bool); */
2955 case TRUTH_NOT_EXPR:
2956 build_builtin_candidate
2957 (candidates, fnname, boolean_type_node,
2958 NULL_TREE, args, argtypes, flags, complain);
2961 case TRUTH_ORIF_EXPR:
2962 case TRUTH_ANDIF_EXPR:
2963 build_builtin_candidate
2964 (candidates, fnname, boolean_type_node,
2965 boolean_type_node, args, argtypes, flags, complain);
2987 types[0] = make_tree_vector ();
2988 types[1] = make_tree_vector ();
2990 for (i = 0; i < 2; ++i)
2994 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2998 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
3001 convs = lookup_conversions (argtypes[i]);
3003 if (code == COND_EXPR)
3005 if (lvalue_p (args[i]))
3006 vec_safe_push (types[i], build_reference_type (argtypes[i]));
3008 vec_safe_push (types[i], TYPE_MAIN_VARIANT (argtypes[i]));
3014 for (; convs; convs = TREE_CHAIN (convs))
3016 type = TREE_TYPE (convs);
3019 && (TREE_CODE (type) != REFERENCE_TYPE
3020 || CP_TYPE_CONST_P (TREE_TYPE (type))))
3023 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
3024 vec_safe_push (types[i], type);
3026 type = non_reference (type);
3027 if (i != 0 || ! ref1)
3029 type = cv_unqualified (type_decays_to (type));
3030 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
3031 vec_safe_push (types[i], type);
3032 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
3033 type = type_promotes_to (type);
3036 if (! vec_member (type, types[i]))
3037 vec_safe_push (types[i], type);
3042 if (code == COND_EXPR && lvalue_p (args[i]))
3043 vec_safe_push (types[i], build_reference_type (argtypes[i]));
3044 type = non_reference (argtypes[i]);
3045 if (i != 0 || ! ref1)
3047 type = cv_unqualified (type_decays_to (type));
3048 if (enum_p && UNSCOPED_ENUM_P (type))
3049 vec_safe_push (types[i], type);
3050 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
3051 type = type_promotes_to (type);
3053 vec_safe_push (types[i], type);
3057 /* Run through the possible parameter types of both arguments,
3058 creating candidates with those parameter types. */
3059 FOR_EACH_VEC_ELT_REVERSE (*(types[0]), ix, t)
3064 if (!types[1]->is_empty ())
3065 FOR_EACH_VEC_ELT_REVERSE (*(types[1]), jx, u)
3066 add_builtin_candidate
3067 (candidates, code, code2, fnname, t,
3068 u, args, argtypes, flags, complain);
3070 add_builtin_candidate
3071 (candidates, code, code2, fnname, t,
3072 NULL_TREE, args, argtypes, flags, complain);
3075 release_tree_vector (types[0]);
3076 release_tree_vector (types[1]);
3080 /* If TMPL can be successfully instantiated as indicated by
3081 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
3083 TMPL is the template. EXPLICIT_TARGS are any explicit template
3084 arguments. ARGLIST is the arguments provided at the call-site.
3085 This does not change ARGLIST. The RETURN_TYPE is the desired type
3086 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
3087 as for add_function_candidate. If an OBJ is supplied, FLAGS and
3088 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
3090 static struct z_candidate*
3091 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
3092 tree ctype, tree explicit_targs, tree first_arg,
3093 const vec<tree, va_gc> *arglist, tree return_type,
3094 tree access_path, tree conversion_path,
3095 int flags, tree obj, unification_kind_t strict,
3096 tsubst_flags_t complain)
3098 int ntparms = DECL_NTPARMS (tmpl);
3099 tree targs = make_tree_vec (ntparms);
3100 unsigned int len = vec_safe_length (arglist);
3101 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
3102 unsigned int skip_without_in_chrg = 0;
3103 tree first_arg_without_in_chrg = first_arg;
3104 tree *args_without_in_chrg;
3105 unsigned int nargs_without_in_chrg;
3106 unsigned int ia, ix;
3108 struct z_candidate *cand;
3110 struct rejection_reason *reason = NULL;
3113 /* We don't do deduction on the in-charge parameter, the VTT
3114 parameter or 'this'. */
3115 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
3117 if (first_arg_without_in_chrg != NULL_TREE)
3118 first_arg_without_in_chrg = NULL_TREE;
3119 else if (return_type && strict == DEDUCE_CALL)
3120 /* We're deducing for a call to the result of a template conversion
3121 function, so the args don't contain 'this'; leave them alone. */;
3123 ++skip_without_in_chrg;
3126 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
3127 || DECL_BASE_CONSTRUCTOR_P (tmpl))
3128 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
3130 if (first_arg_without_in_chrg != NULL_TREE)
3131 first_arg_without_in_chrg = NULL_TREE;
3133 ++skip_without_in_chrg;
3136 if (len < skip_without_in_chrg)
3139 if (DECL_CONSTRUCTOR_P (tmpl) && nargs == 2
3140 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (first_arg),
3141 TREE_TYPE ((*arglist)[0])))
3143 /* 12.8/6 says, "A declaration of a constructor for a class X is
3144 ill-formed if its first parameter is of type (optionally cv-qualified)
3145 X and either there are no other parameters or else all other
3146 parameters have default arguments. A member function template is never
3147 instantiated to produce such a constructor signature."
3149 So if we're trying to copy an object of the containing class, don't
3150 consider a template constructor that has a first parameter type that
3151 is just a template parameter, as we would deduce a signature that we
3152 would then reject in the code below. */
3153 if (tree firstparm = FUNCTION_FIRST_USER_PARMTYPE (tmpl))
3155 firstparm = TREE_VALUE (firstparm);
3156 if (PACK_EXPANSION_P (firstparm))
3157 firstparm = PACK_EXPANSION_PATTERN (firstparm);
3158 if (TREE_CODE (firstparm) == TEMPLATE_TYPE_PARM)
3160 gcc_assert (!explicit_targs);
3161 reason = invalid_copy_with_fn_template_rejection ();
3167 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
3168 + (len - skip_without_in_chrg));
3169 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
3171 if (first_arg_without_in_chrg != NULL_TREE)
3173 args_without_in_chrg[ia] = first_arg_without_in_chrg;
3176 for (ix = skip_without_in_chrg;
3177 vec_safe_iterate (arglist, ix, &arg);
3180 args_without_in_chrg[ia] = arg;
3183 gcc_assert (ia == nargs_without_in_chrg);
3185 errs = errorcount+sorrycount;
3186 fn = fn_type_unification (tmpl, explicit_targs, targs,
3187 args_without_in_chrg,
3188 nargs_without_in_chrg,
3189 return_type, strict, flags, false,
3190 complain & tf_decltype);
3192 if (fn == error_mark_node)
3194 /* Don't repeat unification later if it already resulted in errors. */
3195 if (errorcount+sorrycount == errs)
3196 reason = template_unification_rejection (tmpl, explicit_targs,
3197 targs, args_without_in_chrg,
3198 nargs_without_in_chrg,
3199 return_type, strict, flags);
3201 reason = template_unification_error_rejection ();
3205 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
3207 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
3208 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
3211 /* We're trying to produce a constructor with a prohibited signature,
3212 as discussed above; handle here any cases we didn't catch then,
3214 reason = invalid_copy_with_fn_template_rejection ();
3219 if (obj != NULL_TREE)
3220 /* Aha, this is a conversion function. */
3221 cand = add_conv_candidate (candidates, fn, obj, arglist,
3222 access_path, conversion_path, complain);
3224 cand = add_function_candidate (candidates, fn, ctype,
3225 first_arg, arglist, access_path,
3226 conversion_path, flags, complain);
3227 if (DECL_TI_TEMPLATE (fn) != tmpl)
3228 /* This situation can occur if a member template of a template
3229 class is specialized. Then, instantiate_template might return
3230 an instantiation of the specialization, in which case the
3231 DECL_TI_TEMPLATE field will point at the original
3232 specialization. For example:
3234 template <class T> struct S { template <class U> void f(U);
3235 template <> void f(int) {}; };
3239 Here, TMPL will be template <class U> S<double>::f(U).
3240 And, instantiate template will give us the specialization
3241 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
3242 for this will point at template <class T> template <> S<T>::f(int),
3243 so that we can find the definition. For the purposes of
3244 overload resolution, however, we want the original TMPL. */
3245 cand->template_decl = build_template_info (tmpl, targs);
3247 cand->template_decl = DECL_TEMPLATE_INFO (fn);
3248 cand->explicit_targs = explicit_targs;
3252 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
3253 access_path, conversion_path, 0, reason, flags);
3257 static struct z_candidate *
3258 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
3259 tree explicit_targs, tree first_arg,
3260 const vec<tree, va_gc> *arglist, tree return_type,
3261 tree access_path, tree conversion_path, int flags,
3262 unification_kind_t strict, tsubst_flags_t complain)
3265 add_template_candidate_real (candidates, tmpl, ctype,
3266 explicit_targs, first_arg, arglist,
3267 return_type, access_path, conversion_path,
3268 flags, NULL_TREE, strict, complain);
3271 /* Create an overload candidate for the conversion function template TMPL,
3272 returning RETURN_TYPE, which will be invoked for expression OBJ to produce a
3273 pointer-to-function which will in turn be called with the argument list
3274 ARGLIST, and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
3275 passed on to implicit_conversion. */
3277 static struct z_candidate *
3278 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
3280 const vec<tree, va_gc> *arglist,
3281 tree return_type, tree access_path,
3282 tree conversion_path, tsubst_flags_t complain)
3284 /* Making this work broke PR 71117 and 85118, so until the committee resolves
3285 core issue 2189, let's disable this candidate if there are any call
3291 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
3292 NULL_TREE, arglist, return_type, access_path,
3293 conversion_path, 0, obj, DEDUCE_CALL,
3297 /* The CANDS are the set of candidates that were considered for
3298 overload resolution. Return the set of viable candidates, or CANDS
3299 if none are viable. If any of the candidates were viable, set
3300 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3301 considered viable only if it is strictly viable. */
3303 static struct z_candidate*
3304 splice_viable (struct z_candidate *cands,
3308 struct z_candidate *viable;
3309 struct z_candidate **last_viable;
3310 struct z_candidate **cand;
3311 bool found_strictly_viable = false;
3313 /* Be strict inside templates, since build_over_call won't actually
3314 do the conversions to get pedwarns. */
3315 if (processing_template_decl)
3319 last_viable = &viable;
3320 *any_viable_p = false;
3325 struct z_candidate *c = *cand;
3327 && (c->viable == 1 || TREE_CODE (c->fn) == TEMPLATE_DECL))
3329 /* Be strict in the presence of a viable candidate. Also if
3330 there are template candidates, so that we get deduction errors
3331 for them instead of silently preferring a bad conversion. */
3333 if (viable && !found_strictly_viable)
3335 /* Put any spliced near matches back onto the main list so
3336 that we see them if there is no strict match. */
3337 *any_viable_p = false;
3338 *last_viable = cands;
3341 last_viable = &viable;
3345 if (strict_p ? c->viable == 1 : c->viable)
3350 last_viable = &c->next;
3351 *any_viable_p = true;
3353 found_strictly_viable = true;
3359 return viable ? viable : cands;
3363 any_strictly_viable (struct z_candidate *cands)
3365 for (; cands; cands = cands->next)
3366 if (cands->viable == 1)
3371 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3372 words, it is about to become the "this" pointer for a member
3373 function call. Take the address of the object. */
3376 build_this (tree obj)
3378 /* In a template, we are only concerned about the type of the
3379 expression, so we can take a shortcut. */
3380 if (processing_template_decl)
3381 return build_address (obj);
3383 return cp_build_addr_expr (obj, tf_warning_or_error);
3386 /* Returns true iff functions are equivalent. Equivalent functions are
3387 not '==' only if one is a function-local extern function or if
3388 both are extern "C". */
3391 equal_functions (tree fn1, tree fn2)
3393 if (TREE_CODE (fn1) != TREE_CODE (fn2))
3395 if (TREE_CODE (fn1) == TEMPLATE_DECL)
3397 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
3398 || DECL_EXTERN_C_FUNCTION_P (fn1))
3399 return decls_match (fn1, fn2);
3403 /* Print information about a candidate being rejected due to INFO. */
3406 print_conversion_rejection (location_t loc, struct conversion_info *info)
3408 tree from = info->from;
3410 from = lvalue_type (from);
3411 if (info->n_arg == -1)
3413 /* Conversion of implicit `this' argument failed. */
3414 if (!TYPE_P (info->from))
3415 /* A bad conversion for 'this' must be discarding cv-quals. */
3416 inform (loc, " passing %qT as %<this%> "
3417 "argument discards qualifiers",
3420 inform (loc, " no known conversion for implicit "
3421 "%<this%> parameter from %qH to %qI",
3422 from, info->to_type);
3424 else if (!TYPE_P (info->from))
3426 if (info->n_arg >= 0)
3427 inform (loc, " conversion of argument %d would be ill-formed:",
3429 perform_implicit_conversion (info->to_type, info->from,
3430 tf_warning_or_error);
3432 else if (info->n_arg == -2)
3433 /* Conversion of conversion function return value failed. */
3434 inform (loc, " no known conversion from %qH to %qI",
3435 from, info->to_type);
3437 inform (loc, " no known conversion for argument %d from %qH to %qI",
3438 info->n_arg + 1, from, info->to_type);
3441 /* Print information about a candidate with WANT parameters and we found
3445 print_arity_information (location_t loc, unsigned int have, unsigned int want)
3447 inform_n (loc, want,
3448 " candidate expects %d argument, %d provided",
3449 " candidate expects %d arguments, %d provided",
3453 /* Print information about one overload candidate CANDIDATE. MSGSTR
3454 is the text to print before the candidate itself.
3456 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3457 to have been run through gettext by the caller. This wart makes
3458 life simpler in print_z_candidates and for the translators. */
3461 print_z_candidate (location_t loc, const char *msgstr,
3462 struct z_candidate *candidate)
3464 const char *msg = (msgstr == NULL
3466 : ACONCAT ((msgstr, " ", NULL)));
3467 tree fn = candidate->fn;
3468 if (flag_new_inheriting_ctors)
3469 fn = strip_inheriting_ctors (fn);
3470 location_t cloc = location_of (fn);
3472 if (identifier_p (fn))
3475 if (candidate->num_convs == 3)
3476 inform (cloc, "%s%<%D(%T, %T, %T)%> <built-in>", msg, fn,
3477 candidate->convs[0]->type,
3478 candidate->convs[1]->type,
3479 candidate->convs[2]->type);
3480 else if (candidate->num_convs == 2)
3481 inform (cloc, "%s%<%D(%T, %T)%> <built-in>", msg, fn,
3482 candidate->convs[0]->type,
3483 candidate->convs[1]->type);
3485 inform (cloc, "%s%<%D(%T)%> <built-in>", msg, fn,
3486 candidate->convs[0]->type);
3488 else if (TYPE_P (fn))
3489 inform (cloc, "%s%qT <conversion>", msg, fn);
3490 else if (candidate->viable == -1)
3491 inform (cloc, "%s%#qD <near match>", msg, fn);
3492 else if (DECL_DELETED_FN (fn))
3493 inform (cloc, "%s%#qD <deleted>", msg, fn);
3495 inform (cloc, "%s%#qD", msg, fn);
3496 if (fn != candidate->fn)
3498 cloc = location_of (candidate->fn);
3499 inform (cloc, " inherited here");
3501 /* Give the user some information about why this candidate failed. */
3502 if (candidate->reason != NULL)
3504 struct rejection_reason *r = candidate->reason;
3509 print_arity_information (cloc, r->u.arity.actual,
3510 r->u.arity.expected);
3512 case rr_arg_conversion:
3513 print_conversion_rejection (cloc, &r->u.conversion);
3515 case rr_bad_arg_conversion:
3516 print_conversion_rejection (cloc, &r->u.bad_conversion);
3518 case rr_explicit_conversion:
3519 inform (cloc, " return type %qT of explicit conversion function "
3520 "cannot be converted to %qT with a qualification "
3521 "conversion", r->u.conversion.from,
3522 r->u.conversion.to_type);
3524 case rr_template_conversion:
3525 inform (cloc, " conversion from return type %qT of template "
3526 "conversion function specialization to %qT is not an "
3527 "exact match", r->u.conversion.from,
3528 r->u.conversion.to_type);
3530 case rr_template_unification:
3531 /* We use template_unification_error_rejection if unification caused
3532 actual non-SFINAE errors, in which case we don't need to repeat
3534 if (r->u.template_unification.tmpl == NULL_TREE)
3536 inform (cloc, " substitution of deduced template arguments "
3537 "resulted in errors seen above");
3540 /* Re-run template unification with diagnostics. */
3541 inform (cloc, " template argument deduction/substitution failed:");
3542 fn_type_unification (r->u.template_unification.tmpl,
3543 r->u.template_unification.explicit_targs,
3545 (r->u.template_unification.num_targs)),
3546 r->u.template_unification.args,
3547 r->u.template_unification.nargs,
3548 r->u.template_unification.return_type,
3549 r->u.template_unification.strict,
3550 r->u.template_unification.flags,
3553 case rr_invalid_copy:
3555 " a constructor taking a single argument of its own "
3556 "class type is invalid");
3558 case rr_constraint_failure:
3560 tree tmpl = r->u.template_instantiation.tmpl;
3561 tree args = r->u.template_instantiation.targs;
3562 diagnose_constraints (cloc, tmpl, args);
3565 case rr_inherited_ctor:
3566 inform (cloc, " an inherited constructor is not a candidate for "
3567 "initialization from an expression of the same or derived "
3572 /* This candidate didn't have any issues or we failed to
3573 handle a particular code. Either way... */
3580 print_z_candidates (location_t loc, struct z_candidate *candidates)
3582 struct z_candidate *cand1;
3583 struct z_candidate **cand2;
3588 /* Remove non-viable deleted candidates. */
3590 for (cand2 = &cand1; *cand2; )
3592 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3593 && !(*cand2)->viable
3594 && DECL_DELETED_FN ((*cand2)->fn))
3595 *cand2 = (*cand2)->next;
3597 cand2 = &(*cand2)->next;
3599 /* ...if there are any non-deleted ones. */
3603 /* There may be duplicates in the set of candidates. We put off
3604 checking this condition as long as possible, since we have no way
3605 to eliminate duplicates from a set of functions in less than n^2
3606 time. Now we are about to emit an error message, so it is more
3607 permissible to go slowly. */
3608 for (cand1 = candidates; cand1; cand1 = cand1->next)
3610 tree fn = cand1->fn;
3611 /* Skip builtin candidates and conversion functions. */
3614 cand2 = &cand1->next;
3617 if (DECL_P ((*cand2)->fn)
3618 && equal_functions (fn, (*cand2)->fn))
3619 *cand2 = (*cand2)->next;
3621 cand2 = &(*cand2)->next;
3625 for (; candidates; candidates = candidates->next)
3626 print_z_candidate (loc, "candidate:", candidates);
3629 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3630 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3631 the result of the conversion function to convert it to the final
3632 desired type. Merge the two sequences into a single sequence,
3633 and return the merged sequence. */
3636 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3639 bool bad = user_seq->bad_p;
3641 gcc_assert (user_seq->kind == ck_user);
3643 /* Find the end of the second conversion sequence. */
3644 for (t = &std_seq; (*t)->kind != ck_identity; t = &((*t)->u.next))
3646 /* The entire sequence is a user-conversion sequence. */
3647 (*t)->user_conv_p = true;
3652 if ((*t)->rvaluedness_matches_p)
3653 /* We're binding a reference directly to the result of the conversion.
3654 build_user_type_conversion_1 stripped the REFERENCE_TYPE from the return
3655 type, but we want it back. */
3656 user_seq->type = TREE_TYPE (TREE_TYPE (user_seq->cand->fn));
3658 /* Replace the identity conversion with the user conversion
3665 /* Handle overload resolution for initializing an object of class type from
3666 an initializer list. First we look for a suitable constructor that
3667 takes a std::initializer_list; if we don't find one, we then look for a
3668 non-list constructor.
3670 Parameters are as for add_candidates, except that the arguments are in
3671 the form of a CONSTRUCTOR (the initializer list) rather than a vector, and
3672 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3675 add_list_candidates (tree fns, tree first_arg,
3676 const vec<tree, va_gc> *args, tree totype,
3677 tree explicit_targs, bool template_only,
3678 tree conversion_path, tree access_path,
3680 struct z_candidate **candidates,
3681 tsubst_flags_t complain)
3683 gcc_assert (*candidates == NULL);
3685 /* We're looking for a ctor for list-initialization. */
3686 flags |= LOOKUP_LIST_INIT_CTOR;
3687 /* And we don't allow narrowing conversions. We also use this flag to
3688 avoid the copy constructor call for copy-list-initialization. */
3689 flags |= LOOKUP_NO_NARROWING;
3691 unsigned nart = num_artificial_parms_for (OVL_FIRST (fns)) - 1;
3692 tree init_list = (*args)[nart];
3694 /* Always use the default constructor if the list is empty (DR 990). */
3695 if (CONSTRUCTOR_NELTS (init_list) == 0
3696 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3698 /* If the class has a list ctor, try passing the list as a single
3699 argument first, but only consider list ctors. */
3700 else if (TYPE_HAS_LIST_CTOR (totype))
3702 flags |= LOOKUP_LIST_ONLY;
3703 add_candidates (fns, first_arg, args, NULL_TREE,
3704 explicit_targs, template_only, conversion_path,
3705 access_path, flags, candidates, complain);
3706 if (any_strictly_viable (*candidates))
3710 /* Expand the CONSTRUCTOR into a new argument vec. */
3711 vec<tree, va_gc> *new_args;
3712 vec_alloc (new_args, nart + CONSTRUCTOR_NELTS (init_list));
3713 for (unsigned i = 0; i < nart; ++i)
3714 new_args->quick_push ((*args)[i]);
3715 for (unsigned i = 0; i < CONSTRUCTOR_NELTS (init_list); ++i)
3716 new_args->quick_push (CONSTRUCTOR_ELT (init_list, i)->value);
3718 /* We aren't looking for list-ctors anymore. */
3719 flags &= ~LOOKUP_LIST_ONLY;
3720 /* We allow more user-defined conversions within an init-list. */
3721 flags &= ~LOOKUP_NO_CONVERSION;
3723 add_candidates (fns, first_arg, new_args, NULL_TREE,
3724 explicit_targs, template_only, conversion_path,
3725 access_path, flags, candidates, complain);
3728 /* Returns the best overload candidate to perform the requested
3729 conversion. This function is used for three the overloading situations
3730 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3731 If TOTYPE is a REFERENCE_TYPE, we're trying to find a direct binding as
3732 per [dcl.init.ref], so we ignore temporary bindings. */
3734 static struct z_candidate *
3735 build_user_type_conversion_1 (tree totype, tree expr, int flags,
3736 tsubst_flags_t complain)
3738 struct z_candidate *candidates, *cand;
3740 tree ctors = NULL_TREE;
3741 tree conv_fns = NULL_TREE;
3742 conversion *conv = NULL;
3743 tree first_arg = NULL_TREE;
3744 vec<tree, va_gc> *args = NULL;
3751 fromtype = TREE_TYPE (expr);
3753 /* We represent conversion within a hierarchy using RVALUE_CONV and
3754 BASE_CONV, as specified by [over.best.ics]; these become plain
3755 constructor calls, as specified in [dcl.init]. */
3756 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3757 || !DERIVED_FROM_P (totype, fromtype));
3759 if (CLASS_TYPE_P (totype))
3760 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3761 creating a garbage BASELINK; constructors can't be inherited. */
3762 ctors = get_class_binding (totype, complete_ctor_identifier);
3764 if (MAYBE_CLASS_TYPE_P (fromtype))
3766 tree to_nonref = non_reference (totype);
3767 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3768 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3769 && DERIVED_FROM_P (to_nonref, fromtype)))
3771 /* [class.conv.fct] A conversion function is never used to
3772 convert a (possibly cv-qualified) object to the (possibly
3773 cv-qualified) same object type (or a reference to it), to a
3774 (possibly cv-qualified) base class of that type (or a
3775 reference to it)... */
3778 conv_fns = lookup_conversions (fromtype);
3782 flags |= LOOKUP_NO_CONVERSION;
3783 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3784 flags |= LOOKUP_NO_NARROWING;
3786 /* It's OK to bind a temporary for converting constructor arguments, but
3787 not in converting the return value of a conversion operator. */
3788 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION
3789 | (flags & LOOKUP_NO_NARROWING));
3790 flags &= ~LOOKUP_NO_TEMP_BIND;
3794 int ctorflags = flags;
3796 first_arg = build_dummy_object (totype);
3798 /* We should never try to call the abstract or base constructor
3800 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_FIRST (ctors))
3801 && !DECL_HAS_VTT_PARM_P (OVL_FIRST (ctors)));
3803 args = make_tree_vector_single (expr);
3804 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3806 /* List-initialization. */
3807 add_list_candidates (ctors, first_arg, args, totype, NULL_TREE,
3808 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3809 ctorflags, &candidates, complain);
3813 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3814 TYPE_BINFO (totype), TYPE_BINFO (totype),
3815 ctorflags, &candidates, complain);
3818 for (cand = candidates; cand; cand = cand->next)
3820 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3822 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3823 set, then this is copy-initialization. In that case, "The
3824 result of the call is then used to direct-initialize the
3825 object that is the destination of the copy-initialization."
3828 We represent this in the conversion sequence with an
3829 rvalue conversion, which means a constructor call. */
3830 if (TREE_CODE (totype) != REFERENCE_TYPE
3831 && !(convflags & LOOKUP_NO_TEMP_BIND))
3833 = build_conv (ck_rvalue, totype, cand->second_conv);
3839 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3840 first_arg = CONSTRUCTOR_ELT (expr, 0)->value;
3845 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3847 tree conversion_path = TREE_PURPOSE (conv_fns);
3848 struct z_candidate *old_candidates;
3850 /* If we are called to convert to a reference type, we are trying to
3851 find a direct binding, so don't even consider temporaries. If
3852 we don't find a direct binding, the caller will try again to
3853 look for a temporary binding. */
3854 if (TREE_CODE (totype) == REFERENCE_TYPE)
3855 convflags |= LOOKUP_NO_TEMP_BIND;
3857 old_candidates = candidates;
3858 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3860 conversion_path, TYPE_BINFO (fromtype),
3861 flags, &candidates, complain);
3863 for (cand = candidates; cand != old_candidates; cand = cand->next)
3865 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3867 = implicit_conversion (totype,
3870 /*c_cast_p=*/false, convflags,
3873 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3874 copy-initialization. In that case, "The result of the
3875 call is then used to direct-initialize the object that is
3876 the destination of the copy-initialization." [dcl.init]
3878 We represent this in the conversion sequence with an
3879 rvalue conversion, which means a constructor call. But
3880 don't add a second rvalue conversion if there's already
3881 one there. Which there really shouldn't be, but it's
3882 harmless since we'd add it here anyway. */
3883 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3884 && !(convflags & LOOKUP_NO_TEMP_BIND))
3885 ics = build_conv (ck_rvalue, totype, ics);
3887 cand->second_conv = ics;
3892 cand->reason = arg_conversion_rejection (NULL_TREE, -2,
3895 else if (DECL_NONCONVERTING_P (cand->fn)
3896 && ics->rank > cr_exact)
3898 /* 13.3.1.5: For direct-initialization, those explicit
3899 conversion functions that are not hidden within S and
3900 yield type T or a type that can be converted to type T
3901 with a qualification conversion (4.4) are also candidate
3903 /* 13.3.1.6 doesn't have a parallel restriction, but it should;
3904 I've raised this issue with the committee. --jason 9/2011 */
3906 cand->reason = explicit_conversion_rejection (rettype, totype);
3908 else if (cand->viable == 1 && ics->bad_p)
3912 = bad_arg_conversion_rejection (NULL_TREE, -2,
3915 else if (primary_template_specialization_p (cand->fn)
3916 && ics->rank > cr_exact)
3918 /* 13.3.3.1.2: If the user-defined conversion is specified by
3919 a specialization of a conversion function template, the
3920 second standard conversion sequence shall have exact match
3923 cand->reason = template_conversion_rejection (rettype, totype);
3928 candidates = splice_viable (candidates, false, &any_viable_p);
3932 release_tree_vector (args);
3936 cand = tourney (candidates, complain);
3939 if (complain & tf_error)
3941 error ("conversion from %qH to %qI is ambiguous",
3943 print_z_candidates (location_of (expr), candidates);
3946 cand = candidates; /* any one will do */
3947 cand->second_conv = build_ambiguous_conv (totype, expr);
3948 cand->second_conv->user_conv_p = true;
3949 if (!any_strictly_viable (candidates))
3950 cand->second_conv->bad_p = true;
3951 if (flags & LOOKUP_ONLYCONVERTING)
3952 cand->second_conv->need_temporary_p = true;
3953 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3954 ambiguous conversion is no worse than another user-defined
3961 if (!DECL_CONSTRUCTOR_P (cand->fn))
3962 convtype = non_reference (TREE_TYPE (TREE_TYPE (cand->fn)));
3963 else if (cand->second_conv->kind == ck_rvalue)
3964 /* DR 5: [in the first step of copy-initialization]...if the function
3965 is a constructor, the call initializes a temporary of the
3966 cv-unqualified version of the destination type. */
3967 convtype = cv_unqualified (totype);
3970 /* Build the user conversion sequence. */
3974 build_identity_conv (TREE_TYPE (expr), expr));
3976 if (cand->viable == -1)
3979 /* Remember that this was a list-initialization. */
3980 if (flags & LOOKUP_NO_NARROWING)
3981 conv->check_narrowing = true;
3983 /* Combine it with the second conversion sequence. */
3984 cand->second_conv = merge_conversion_sequences (conv,
3990 /* Wrapper for above. */
3993 build_user_type_conversion (tree totype, tree expr, int flags,
3994 tsubst_flags_t complain)
3996 struct z_candidate *cand;
3999 bool subtime = timevar_cond_start (TV_OVERLOAD);
4000 cand = build_user_type_conversion_1 (totype, expr, flags, complain);
4004 if (cand->second_conv->kind == ck_ambig)
4005 ret = error_mark_node;
4008 expr = convert_like (cand->second_conv, expr, complain);
4009 ret = convert_from_reference (expr);
4015 timevar_cond_stop (TV_OVERLOAD, subtime);
4019 /* Subroutine of convert_nontype_argument.
4021 EXPR is an expression used in a context that requires a converted
4022 constant-expression, such as a template non-type parameter. Do any
4023 necessary conversions (that are permitted for converted
4024 constant-expressions) to convert it to the desired type.
4026 If conversion is successful, returns the converted expression;
4027 otherwise, returns error_mark_node. */
4030 build_converted_constant_expr (tree type, tree expr, tsubst_flags_t complain)
4035 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
4037 if (error_operand_p (expr))
4038 return error_mark_node;
4040 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4041 p = conversion_obstack_alloc (0);
4043 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
4045 LOOKUP_IMPLICIT, complain);
4047 /* A converted constant expression of type T is an expression, implicitly
4048 converted to type T, where the converted expression is a constant
4049 expression and the implicit conversion sequence contains only
4051 * user-defined conversions,
4052 * lvalue-to-rvalue conversions (7.1),
4053 * array-to-pointer conversions (7.2),
4054 * function-to-pointer conversions (7.3),
4055 * qualification conversions (7.5),
4056 * integral promotions (7.6),
4057 * integral conversions (7.8) other than narrowing conversions (11.6.4),
4058 * null pointer conversions (7.11) from std::nullptr_t,
4059 * null member pointer conversions (7.12) from std::nullptr_t, and
4060 * function pointer conversions (7.13),
4062 and where the reference binding (if any) binds directly. */
4064 for (conversion *c = conv;
4065 conv && c->kind != ck_identity;
4066 c = next_conversion (c))
4070 /* A conversion function is OK. If it isn't constexpr, we'll
4071 complain later that the argument isn't constant. */
4073 /* The lvalue-to-rvalue conversion is OK. */
4075 /* Array-to-pointer and function-to-pointer. */
4077 /* Function pointer conversions. */
4079 /* Qualification conversions. */
4084 if (c->need_temporary_p)
4086 if (complain & tf_error)
4087 error_at (loc, "initializing %qH with %qI in converted "
4088 "constant expression does not bind directly",
4089 type, next_conversion (c)->type);
4098 t = next_conversion (c)->type;
4099 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t)
4100 && INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4101 /* Integral promotion or conversion. */
4103 if (NULLPTR_TYPE_P (t))
4104 /* Conversion from nullptr to pointer or pointer-to-member. */
4107 if (complain & tf_error)
4108 error_at (loc, "conversion from %qH to %qI in a "
4109 "converted constant expression", t, type);
4118 /* Avoid confusing convert_nontype_argument by introducing
4119 a redundant conversion to the same reference type. */
4120 if (conv && conv->kind == ck_ref_bind
4121 && REFERENCE_REF_P (expr))
4123 tree ref = TREE_OPERAND (expr, 0);
4124 if (same_type_p (type, TREE_TYPE (ref)))
4129 expr = convert_like (conv, expr, complain);
4131 expr = error_mark_node;
4133 /* Free all the conversions we allocated. */
4134 obstack_free (&conversion_obstack, p);
4139 /* Do any initial processing on the arguments to a function call. */
4141 static vec<tree, va_gc> *
4142 resolve_args (vec<tree, va_gc> *args, tsubst_flags_t complain)
4147 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
4149 if (error_operand_p (arg))
4151 else if (VOID_TYPE_P (TREE_TYPE (arg)))
4153 if (complain & tf_error)
4154 error ("invalid use of void expression");
4157 else if (invalid_nonstatic_memfn_p (input_location, arg, complain))
4163 /* Perform overload resolution on FN, which is called with the ARGS.
4165 Return the candidate function selected by overload resolution, or
4166 NULL if the event that overload resolution failed. In the case
4167 that overload resolution fails, *CANDIDATES will be the set of
4168 candidates considered, and ANY_VIABLE_P will be set to true or
4169 false to indicate whether or not any of the candidates were
4172 The ARGS should already have gone through RESOLVE_ARGS before this
4173 function is called. */
4175 static struct z_candidate *
4176 perform_overload_resolution (tree fn,
4177 const vec<tree, va_gc> *args,
4178 struct z_candidate **candidates,
4179 bool *any_viable_p, tsubst_flags_t complain)
4181 struct z_candidate *cand;
4182 tree explicit_targs;
4185 bool subtime = timevar_cond_start (TV_OVERLOAD);
4187 explicit_targs = NULL_TREE;
4191 *any_viable_p = true;
4194 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
4195 || TREE_CODE (fn) == TEMPLATE_DECL
4196 || TREE_CODE (fn) == OVERLOAD
4197 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
4199 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4201 explicit_targs = TREE_OPERAND (fn, 1);
4202 fn = TREE_OPERAND (fn, 0);
4206 /* Add the various candidate functions. */
4207 add_candidates (fn, NULL_TREE, args, NULL_TREE,
4208 explicit_targs, template_only,
4209 /*conversion_path=*/NULL_TREE,
4210 /*access_path=*/NULL_TREE,
4212 candidates, complain);
4214 *candidates = splice_viable (*candidates, false, any_viable_p);
4216 cand = tourney (*candidates, complain);
4220 timevar_cond_stop (TV_OVERLOAD, subtime);
4224 /* Print an error message about being unable to build a call to FN with
4225 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
4226 be located; CANDIDATES is a possibly empty list of such
4230 print_error_for_call_failure (tree fn, vec<tree, va_gc> *args,
4231 struct z_candidate *candidates)
4233 tree targs = NULL_TREE;
4234 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4236 targs = TREE_OPERAND (fn, 1);
4237 fn = TREE_OPERAND (fn, 0);
4239 tree name = OVL_NAME (fn);
4240 location_t loc = location_of (name);
4242 name = lookup_template_function (name, targs);
4244 if (!any_strictly_viable (candidates))
4245 error_at (loc, "no matching function for call to %<%D(%A)%>",
4246 name, build_tree_list_vec (args));
4248 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
4249 name, build_tree_list_vec (args));
4251 print_z_candidates (loc, candidates);
4254 /* Return an expression for a call to FN (a namespace-scope function,
4255 or a static member function) with the ARGS. This may change
4259 build_new_function_call (tree fn, vec<tree, va_gc> **args,
4260 tsubst_flags_t complain)
4262 struct z_candidate *candidates, *cand;
4267 if (args != NULL && *args != NULL)
4269 *args = resolve_args (*args, complain);
4271 return error_mark_node;
4275 tm_malloc_replacement (fn);
4277 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4278 p = conversion_obstack_alloc (0);
4280 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p,
4285 if (complain & tf_error)
4287 // If there is a single (non-viable) function candidate,
4288 // let the error be diagnosed by cp_build_function_call_vec.
4289 if (!any_viable_p && candidates && ! candidates->next
4290 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
4291 return cp_build_function_call_vec (candidates->fn, args, complain);
4293 // Otherwise, emit notes for non-viable candidates.
4294 print_error_for_call_failure (fn, *args, candidates);
4296 result = error_mark_node;
4300 int flags = LOOKUP_NORMAL;
4301 /* If fn is template_id_expr, the call has explicit template arguments
4302 (e.g. func<int>(5)), communicate this info to build_over_call
4303 through flags so that later we can use it to decide whether to warn
4304 about peculiar null pointer conversion. */
4305 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
4307 /* If overload resolution selects a specialization of a
4308 function concept for non-dependent template arguments,
4309 the expression is true if the constraints are satisfied
4310 and false otherwise.
4312 NOTE: This is an extension of Concepts Lite TS that
4313 allows constraints to be used in expressions. */
4314 if (flag_concepts && !processing_template_decl)
4316 tree tmpl = DECL_TI_TEMPLATE (cand->fn);
4317 tree targs = DECL_TI_ARGS (cand->fn);
4318 tree decl = DECL_TEMPLATE_RESULT (tmpl);
4319 if (DECL_DECLARED_CONCEPT_P (decl))
4320 return evaluate_function_concept (decl, targs);
4323 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
4326 result = build_over_call (cand, flags, complain);
4329 /* Free all the conversions we allocated. */
4330 obstack_free (&conversion_obstack, p);
4335 /* Build a call to a global operator new. FNNAME is the name of the
4336 operator (either "operator new" or "operator new[]") and ARGS are
4337 the arguments provided. This may change ARGS. *SIZE points to the
4338 total number of bytes required by the allocation, and is updated if
4339 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
4340 be used. If this function determines that no cookie should be
4341 used, after all, *COOKIE_SIZE is set to NULL_TREE. If SIZE_CHECK
4342 is not NULL_TREE, it is evaluated before calculating the final
4343 array size, and if it fails, the array size is replaced with
4344 (size_t)-1 (usually triggering a std::bad_alloc exception). If FN
4345 is non-NULL, it will be set, upon return, to the allocation
4349 build_operator_new_call (tree fnname, vec<tree, va_gc> **args,
4350 tree *size, tree *cookie_size,
4351 tree align_arg, tree size_check,
4352 tree *fn, tsubst_flags_t complain)
4354 tree original_size = *size;
4356 struct z_candidate *candidates;
4357 struct z_candidate *cand = NULL;
4362 /* Set to (size_t)-1 if the size check fails. */
4363 if (size_check != NULL_TREE)
4365 tree errval = TYPE_MAX_VALUE (sizetype);
4366 if (cxx_dialect >= cxx11 && flag_exceptions)
4367 errval = throw_bad_array_new_length ();
4368 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4369 original_size, errval);
4371 vec_safe_insert (*args, 0, *size);
4372 *args = resolve_args (*args, complain);
4374 return error_mark_node;
4380 If this lookup fails to find the name, or if the allocated type
4381 is not a class type, the allocation function's name is looked
4382 up in the global scope.
4384 we disregard block-scope declarations of "operator new". */
4385 fns = lookup_name_real (fnname, 0, 1, /*block_p=*/false, 0, 0);
4386 fns = lookup_arg_dependent (fnname, fns, *args);
4390 vec<tree, va_gc>* align_args
4391 = vec_copy_and_insert (*args, align_arg, 1);
4392 cand = perform_overload_resolution (fns, align_args, &candidates,
4393 &any_viable_p, tf_none);
4396 /* If no aligned allocation function matches, try again without the
4400 /* Figure out what function is being called. */
4402 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p,
4405 /* If no suitable function could be found, issue an error message
4409 if (complain & tf_error)
4410 print_error_for_call_failure (fns, *args, candidates);
4411 return error_mark_node;
4414 /* If a cookie is required, add some extra space. Whether
4415 or not a cookie is required cannot be determined until
4416 after we know which function was called. */
4419 bool use_cookie = true;
4422 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
4423 /* Skip the size_t parameter. */
4424 arg_types = TREE_CHAIN (arg_types);
4425 /* Check the remaining parameters (if any). */
4427 && TREE_CHAIN (arg_types) == void_list_node
4428 && same_type_p (TREE_VALUE (arg_types),
4431 /* If we need a cookie, adjust the number of bytes allocated. */
4434 /* Update the total size. */
4435 *size = size_binop (PLUS_EXPR, original_size, *cookie_size);
4438 /* Set to (size_t)-1 if the size check fails. */
4439 gcc_assert (size_check != NULL_TREE);
4440 *size = fold_build3 (COND_EXPR, sizetype, size_check,
4441 *size, TYPE_MAX_VALUE (sizetype));
4443 /* Update the argument list to reflect the adjusted size. */
4444 (**args)[0] = *size;
4447 *cookie_size = NULL_TREE;
4450 /* Tell our caller which function we decided to call. */
4454 /* Build the CALL_EXPR. */
4455 return build_over_call (cand, LOOKUP_NORMAL, complain);
4458 /* Build a new call to operator(). This may change ARGS. */
4461 build_op_call_1 (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4463 struct z_candidate *candidates = 0, *cand;
4464 tree fns, convs, first_mem_arg = NULL_TREE;
4466 tree result = NULL_TREE;
4469 obj = mark_lvalue_use (obj);
4471 if (error_operand_p (obj))
4472 return error_mark_node;
4474 tree type = TREE_TYPE (obj);
4476 obj = prep_operand (obj);
4478 if (TYPE_PTRMEMFUNC_P (type))
4480 if (complain & tf_error)
4481 /* It's no good looking for an overloaded operator() on a
4482 pointer-to-member-function. */
4483 error ("pointer-to-member function %qE cannot be called without "
4484 "an object; consider using %<.*%> or %<->*%>", obj);
4485 return error_mark_node;
4488 if (TYPE_BINFO (type))
4490 fns = lookup_fnfields (TYPE_BINFO (type), call_op_identifier, 1);
4491 if (fns == error_mark_node)
4492 return error_mark_node;
4497 if (args != NULL && *args != NULL)
4499 *args = resolve_args (*args, complain);
4501 return error_mark_node;
4504 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4505 p = conversion_obstack_alloc (0);
4509 first_mem_arg = obj;
4511 add_candidates (BASELINK_FUNCTIONS (fns),
4512 first_mem_arg, *args, NULL_TREE,
4514 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
4515 LOOKUP_NORMAL, &candidates, complain);
4518 convs = lookup_conversions (type);
4520 for (; convs; convs = TREE_CHAIN (convs))
4522 tree totype = TREE_TYPE (convs);
4524 if (TYPE_PTRFN_P (totype)
4525 || TYPE_REFFN_P (totype)
4526 || (TREE_CODE (totype) == REFERENCE_TYPE
4527 && TYPE_PTRFN_P (TREE_TYPE (totype))))
4528 for (ovl_iterator iter (TREE_VALUE (convs)); iter; ++iter)
4532 if (DECL_NONCONVERTING_P (fn))
4535 if (TREE_CODE (fn) == TEMPLATE_DECL)
4536 add_template_conv_candidate
4537 (&candidates, fn, obj, *args, totype,
4538 /*access_path=*/NULL_TREE,
4539 /*conversion_path=*/NULL_TREE, complain);
4541 add_conv_candidate (&candidates, fn, obj,
4542 *args, /*conversion_path=*/NULL_TREE,
4543 /*access_path=*/NULL_TREE, complain);
4547 /* Be strict here because if we choose a bad conversion candidate, the
4548 errors we get won't mention the call context. */
4549 candidates = splice_viable (candidates, true, &any_viable_p);
4552 if (complain & tf_error)
4554 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
4555 build_tree_list_vec (*args));
4556 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4558 result = error_mark_node;
4562 cand = tourney (candidates, complain);
4565 if (complain & tf_error)
4567 error ("call of %<(%T) (%A)%> is ambiguous",
4568 TREE_TYPE (obj), build_tree_list_vec (*args));
4569 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4571 result = error_mark_node;
4573 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
4574 && DECL_OVERLOADED_OPERATOR_P (cand->fn)
4575 && DECL_OVERLOADED_OPERATOR_IS (cand->fn, CALL_EXPR))
4576 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4579 if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4580 obj = convert_like_with_context (cand->convs[0], obj, cand->fn,
4584 gcc_checking_assert (TYPE_P (cand->fn));
4585 obj = convert_like (cand->convs[0], obj, complain);
4587 obj = convert_from_reference (obj);
4588 result = cp_build_function_call_vec (obj, args, complain);
4592 /* Free all the conversions we allocated. */
4593 obstack_free (&conversion_obstack, p);
4598 /* Wrapper for above. */
4601 build_op_call (tree obj, vec<tree, va_gc> **args, tsubst_flags_t complain)
4604 bool subtime = timevar_cond_start (TV_OVERLOAD);
4605 ret = build_op_call_1 (obj, args, complain);
4606 timevar_cond_stop (TV_OVERLOAD, subtime);
4610 /* Called by op_error to prepare format strings suitable for the error
4611 function. It concatenates a prefix (controlled by MATCH), ERRMSG,
4612 and a suffix (controlled by NTYPES). */
4615 op_error_string (const char *errmsg, int ntypes, bool match)
4619 const char *msgp = concat (match ? G_("ambiguous overload for ")
4620 : G_("no match for "), errmsg, NULL);
4623 msg = concat (msgp, G_(" (operand types are %qT, %qT, and %qT)"), NULL);
4624 else if (ntypes == 2)
4625 msg = concat (msgp, G_(" (operand types are %qT and %qT)"), NULL);
4627 msg = concat (msgp, G_(" (operand type is %qT)"), NULL);
4633 op_error (location_t loc, enum tree_code code, enum tree_code code2,
4634 tree arg1, tree arg2, tree arg3, bool match)
4636 bool assop = code == MODIFY_EXPR;
4637 const char *opname = OVL_OP_INFO (assop, assop ? code2 : code)->name;
4642 if (flag_diagnostics_show_caret)
4643 error_at (loc, op_error_string (G_("ternary %<operator?:%>"),
4645 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4647 error_at (loc, op_error_string (G_("ternary %<operator?:%> "
4648 "in %<%E ? %E : %E%>"), 3, match),
4650 TREE_TYPE (arg1), TREE_TYPE (arg2), TREE_TYPE (arg3));
4653 case POSTINCREMENT_EXPR:
4654 case POSTDECREMENT_EXPR:
4655 if (flag_diagnostics_show_caret)
4656 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4657 opname, TREE_TYPE (arg1));
4659 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E%s%>"),
4661 opname, arg1, opname, TREE_TYPE (arg1));
4665 if (flag_diagnostics_show_caret)
4666 error_at (loc, op_error_string (G_("%<operator[]%>"), 2, match),
4667 TREE_TYPE (arg1), TREE_TYPE (arg2));
4669 error_at (loc, op_error_string (G_("%<operator[]%> in %<%E[%E]%>"),
4671 arg1, arg2, TREE_TYPE (arg1), TREE_TYPE (arg2));
4676 if (flag_diagnostics_show_caret)
4677 error_at (loc, op_error_string (G_("%qs"), 1, match),
4678 opname, TREE_TYPE (arg1));
4680 error_at (loc, op_error_string (G_("%qs in %<%s %E%>"), 1, match),
4681 opname, opname, arg1, TREE_TYPE (arg1));
4686 if (flag_diagnostics_show_caret)
4687 error_at (loc, op_error_string (G_("%<operator%s%>"), 2, match),
4688 opname, TREE_TYPE (arg1), TREE_TYPE (arg2));
4690 error_at (loc, op_error_string (G_("%<operator%s%> in %<%E %s %E%>"),
4692 opname, arg1, opname, arg2,
4693 TREE_TYPE (arg1), TREE_TYPE (arg2));
4695 if (flag_diagnostics_show_caret)
4696 error_at (loc, op_error_string (G_("%<operator%s%>"), 1, match),
4697 opname, TREE_TYPE (arg1));
4699 error_at (loc, op_error_string (G_("%<operator%s%> in %<%s%E%>"),
4701 opname, opname, arg1, TREE_TYPE (arg1));
4706 /* Return the implicit conversion sequence that could be used to
4707 convert E1 to E2 in [expr.cond]. */
4710 conditional_conversion (tree e1, tree e2, tsubst_flags_t complain)
4712 tree t1 = non_reference (TREE_TYPE (e1));
4713 tree t2 = non_reference (TREE_TYPE (e2));
4719 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4720 implicitly converted (clause _conv_) to the type "lvalue reference to
4721 T2", subject to the constraint that in the conversion the
4722 reference must bind directly (_dcl.init.ref_) to an lvalue.
4724 If E2 is an xvalue: E1 can be converted to match E2 if E1 can be
4725 implicitly converted to the type "rvalue reference to T2", subject to
4726 the constraint that the reference must bind directly. */
4729 tree rtype = cp_build_reference_type (t2, !lvalue_p (e2));
4730 conv = implicit_conversion (rtype,
4734 LOOKUP_NO_TEMP_BIND|LOOKUP_NO_RVAL_BIND
4735 |LOOKUP_ONLYCONVERTING,
4737 if (conv && !conv->bad_p)
4741 /* If E2 is a prvalue or if neither of the conversions above can be done
4742 and at least one of the operands has (possibly cv-qualified) class
4744 if (!CLASS_TYPE_P (t1) && !CLASS_TYPE_P (t2))
4749 If E1 and E2 have class type, and the underlying class types are
4750 the same or one is a base class of the other: E1 can be converted
4751 to match E2 if the class of T2 is the same type as, or a base
4752 class of, the class of T1, and the cv-qualification of T2 is the
4753 same cv-qualification as, or a greater cv-qualification than, the
4754 cv-qualification of T1. If the conversion is applied, E1 is
4755 changed to an rvalue of type T2 that still refers to the original
4756 source class object (or the appropriate subobject thereof). */
4757 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4758 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4760 if (good_base && at_least_as_qualified_p (t2, t1))
4762 conv = build_identity_conv (t1, e1);
4763 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4764 TYPE_MAIN_VARIANT (t2)))
4765 conv = build_conv (ck_base, t2, conv);
4767 conv = build_conv (ck_rvalue, t2, conv);
4776 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4777 converted to the type that expression E2 would have if E2 were
4778 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4779 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4780 LOOKUP_IMPLICIT, complain);
4783 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4784 arguments to the conditional expression. */
4787 build_conditional_expr_1 (location_t loc, tree arg1, tree arg2, tree arg3,
4788 tsubst_flags_t complain)
4792 tree result = NULL_TREE;
4793 tree result_type = NULL_TREE;
4794 bool is_glvalue = true;
4795 struct z_candidate *candidates = 0;
4796 struct z_candidate *cand;
4798 tree orig_arg2, orig_arg3;
4800 /* As a G++ extension, the second argument to the conditional can be
4801 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4802 c'.) If the second operand is omitted, make sure it is
4803 calculated only once. */
4806 if (complain & tf_error)
4807 pedwarn (loc, OPT_Wpedantic,
4808 "ISO C++ forbids omitting the middle term of a ?: expression");
4810 if ((complain & tf_warning) && !truth_value_p (TREE_CODE (arg1)))
4811 warn_for_omitted_condop (loc, arg1);
4813 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4814 if (lvalue_p (arg1))
4815 arg2 = arg1 = cp_stabilize_reference (arg1);
4817 arg2 = arg1 = cp_save_expr (arg1);
4820 /* If something has already gone wrong, just pass that fact up the
4822 if (error_operand_p (arg1)
4823 || error_operand_p (arg2)
4824 || error_operand_p (arg3))
4825 return error_mark_node;
4830 if (VECTOR_INTEGER_TYPE_P (TREE_TYPE (arg1)))
4832 tree arg1_type = TREE_TYPE (arg1);
4834 /* If arg1 is another cond_expr choosing between -1 and 0,
4835 then we can use its comparison. It may help to avoid
4836 additional comparison, produce more accurate diagnostics
4837 and enables folding. */
4838 if (TREE_CODE (arg1) == VEC_COND_EXPR
4839 && integer_minus_onep (TREE_OPERAND (arg1, 1))
4840 && integer_zerop (TREE_OPERAND (arg1, 2)))
4841 arg1 = TREE_OPERAND (arg1, 0);
4843 arg1 = force_rvalue (arg1, complain);
4844 arg2 = force_rvalue (arg2, complain);
4845 arg3 = force_rvalue (arg3, complain);
4847 /* force_rvalue can return error_mark on valid arguments. */
4848 if (error_operand_p (arg1)
4849 || error_operand_p (arg2)
4850 || error_operand_p (arg3))
4851 return error_mark_node;
4853 arg2_type = TREE_TYPE (arg2);
4854 arg3_type = TREE_TYPE (arg3);
4856 if (!VECTOR_TYPE_P (arg2_type)
4857 && !VECTOR_TYPE_P (arg3_type))
4859 /* Rely on the error messages of the scalar version. */
4860 tree scal = build_conditional_expr_1 (loc, integer_one_node,
4861 orig_arg2, orig_arg3, complain);
4862 if (scal == error_mark_node)
4863 return error_mark_node;
4864 tree stype = TREE_TYPE (scal);
4865 tree ctype = TREE_TYPE (arg1_type);
4866 if (TYPE_SIZE (stype) != TYPE_SIZE (ctype)
4867 || (!INTEGRAL_TYPE_P (stype) && !SCALAR_FLOAT_TYPE_P (stype)))
4869 if (complain & tf_error)
4870 error_at (loc, "inferred scalar type %qT is not an integer or "
4871 "floating point type of the same size as %qT", stype,
4872 COMPARISON_CLASS_P (arg1)
4873 ? TREE_TYPE (TREE_TYPE (TREE_OPERAND (arg1, 0)))
4875 return error_mark_node;
4878 tree vtype = build_opaque_vector_type (stype,
4879 TYPE_VECTOR_SUBPARTS (arg1_type));
4880 /* We could pass complain & tf_warning to unsafe_conversion_p,
4881 but the warnings (like Wsign-conversion) have already been
4882 given by the scalar build_conditional_expr_1. We still check
4883 unsafe_conversion_p to forbid truncating long long -> float. */
4884 if (unsafe_conversion_p (loc, stype, arg2, NULL_TREE, false))
4886 if (complain & tf_error)
4887 error_at (loc, "conversion of scalar %qH to vector %qI "
4888 "involves truncation", arg2_type, vtype);
4889 return error_mark_node;
4891 if (unsafe_conversion_p (loc, stype, arg3, NULL_TREE, false))
4893 if (complain & tf_error)
4894 error_at (loc, "conversion of scalar %qH to vector %qI "
4895 "involves truncation", arg3_type, vtype);
4896 return error_mark_node;
4899 arg2 = cp_convert (stype, arg2, complain);
4900 arg2 = save_expr (arg2);
4901 arg2 = build_vector_from_val (vtype, arg2);
4903 arg3 = cp_convert (stype, arg3, complain);
4904 arg3 = save_expr (arg3);
4905 arg3 = build_vector_from_val (vtype, arg3);
4909 if (VECTOR_TYPE_P (arg2_type) != VECTOR_TYPE_P (arg3_type))
4911 enum stv_conv convert_flag =
4912 scalar_to_vector (loc, VEC_COND_EXPR, arg2, arg3,
4913 complain & tf_error);
4915 switch (convert_flag)
4918 return error_mark_node;
4921 arg2 = save_expr (arg2);
4922 arg2 = convert (TREE_TYPE (arg3_type), arg2);
4923 arg2 = build_vector_from_val (arg3_type, arg2);
4924 arg2_type = TREE_TYPE (arg2);
4929 arg3 = save_expr (arg3);
4930 arg3 = convert (TREE_TYPE (arg2_type), arg3);
4931 arg3 = build_vector_from_val (arg2_type, arg3);
4932 arg3_type = TREE_TYPE (arg3);
4940 if (!same_type_p (arg2_type, arg3_type)
4941 || maybe_ne (TYPE_VECTOR_SUBPARTS (arg1_type),
4942 TYPE_VECTOR_SUBPARTS (arg2_type))
4943 || TYPE_SIZE (arg1_type) != TYPE_SIZE (arg2_type))
4945 if (complain & tf_error)
4947 "incompatible vector types in conditional expression: "
4948 "%qT, %qT and %qT", TREE_TYPE (arg1),
4949 TREE_TYPE (orig_arg2), TREE_TYPE (orig_arg3));
4950 return error_mark_node;
4953 if (!COMPARISON_CLASS_P (arg1))
4955 tree cmp_type = build_same_sized_truth_vector_type (arg1_type);
4956 arg1 = build2 (NE_EXPR, cmp_type, arg1, build_zero_cst (arg1_type));
4958 return build3_loc (loc, VEC_COND_EXPR, arg2_type, arg1, arg2, arg3);
4963 The first expression is implicitly converted to bool (clause
4965 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4967 if (error_operand_p (arg1))
4968 return error_mark_node;
4972 If either the second or the third operand has type (possibly
4973 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4974 array-to-pointer (_conv.array_), and function-to-pointer
4975 (_conv.func_) standard conversions are performed on the second
4976 and third operands. */
4977 arg2_type = unlowered_expr_type (arg2);
4978 arg3_type = unlowered_expr_type (arg3);
4979 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4981 /* Do the conversions. We don't these for `void' type arguments
4982 since it can't have any effect and since decay_conversion
4983 does not handle that case gracefully. */
4984 if (!VOID_TYPE_P (arg2_type))
4985 arg2 = decay_conversion (arg2, complain);
4986 if (!VOID_TYPE_P (arg3_type))
4987 arg3 = decay_conversion (arg3, complain);
4988 arg2_type = TREE_TYPE (arg2);
4989 arg3_type = TREE_TYPE (arg3);
4993 One of the following shall hold:
4995 --The second or the third operand (but not both) is a
4996 throw-expression (_except.throw_); the result is of the
4997 type of the other and is an rvalue.
4999 --Both the second and the third operands have type void; the
5000 result is of type void and is an rvalue.
5002 We must avoid calling force_rvalue for expressions of type
5003 "void" because it will complain that their value is being
5005 if (TREE_CODE (arg2) == THROW_EXPR
5006 && TREE_CODE (arg3) != THROW_EXPR)
5008 if (!VOID_TYPE_P (arg3_type))
5010 arg3 = force_rvalue (arg3, complain);
5011 if (arg3 == error_mark_node)
5012 return error_mark_node;
5014 arg3_type = TREE_TYPE (arg3);
5015 result_type = arg3_type;
5017 else if (TREE_CODE (arg2) != THROW_EXPR
5018 && TREE_CODE (arg3) == THROW_EXPR)
5020 if (!VOID_TYPE_P (arg2_type))
5022 arg2 = force_rvalue (arg2, complain);
5023 if (arg2 == error_mark_node)
5024 return error_mark_node;
5026 arg2_type = TREE_TYPE (arg2);
5027 result_type = arg2_type;
5029 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
5030 result_type = void_type_node;
5033 if (complain & tf_error)
5035 if (VOID_TYPE_P (arg2_type))
5036 error_at (EXPR_LOC_OR_LOC (arg3, loc),
5037 "second operand to the conditional operator "
5038 "is of type %<void%>, but the third operand is "
5039 "neither a throw-expression nor of type %<void%>");
5041 error_at (EXPR_LOC_OR_LOC (arg2, loc),
5042 "third operand to the conditional operator "
5043 "is of type %<void%>, but the second operand is "
5044 "neither a throw-expression nor of type %<void%>");
5046 return error_mark_node;
5050 goto valid_operands;
5054 Otherwise, if the second and third operand have different types,
5055 and either has (possibly cv-qualified) class type, or if both are
5056 glvalues of the same value category and the same type except for
5057 cv-qualification, an attempt is made to convert each of those operands
5058 to the type of the other. */
5059 else if (!same_type_p (arg2_type, arg3_type)
5060 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)
5061 || (same_type_ignoring_top_level_qualifiers_p (arg2_type,
5063 && glvalue_p (arg2) && glvalue_p (arg3)
5064 && lvalue_p (arg2) == lvalue_p (arg3))))
5068 bool converted = false;
5070 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5071 p = conversion_obstack_alloc (0);
5073 conv2 = conditional_conversion (arg2, arg3, complain);
5074 conv3 = conditional_conversion (arg3, arg2, complain);
5078 If both can be converted, or one can be converted but the
5079 conversion is ambiguous, the program is ill-formed. If
5080 neither can be converted, the operands are left unchanged and
5081 further checking is performed as described below. If exactly
5082 one conversion is possible, that conversion is applied to the
5083 chosen operand and the converted operand is used in place of
5084 the original operand for the remainder of this section. */
5085 if ((conv2 && !conv2->bad_p
5086 && conv3 && !conv3->bad_p)
5087 || (conv2 && conv2->kind == ck_ambig)
5088 || (conv3 && conv3->kind == ck_ambig))
5090 if (complain & tf_error)
5092 error_at (loc, "operands to ?: have different types %qT and %qT",
5093 arg2_type, arg3_type);
5094 if (conv2 && !conv2->bad_p && conv3 && !conv3->bad_p)
5095 inform (loc, " and each type can be converted to the other");
5096 else if (conv2 && conv2->kind == ck_ambig)
5097 convert_like (conv2, arg2, complain);
5099 convert_like (conv3, arg3, complain);
5101 result = error_mark_node;
5103 else if (conv2 && !conv2->bad_p)
5105 arg2 = convert_like (conv2, arg2, complain);
5106 arg2 = convert_from_reference (arg2);
5107 arg2_type = TREE_TYPE (arg2);
5108 /* Even if CONV2 is a valid conversion, the result of the
5109 conversion may be invalid. For example, if ARG3 has type
5110 "volatile X", and X does not have a copy constructor
5111 accepting a "volatile X&", then even if ARG2 can be
5112 converted to X, the conversion will fail. */
5113 if (error_operand_p (arg2))
5114 result = error_mark_node;
5117 else if (conv3 && !conv3->bad_p)
5119 arg3 = convert_like (conv3, arg3, complain);
5120 arg3 = convert_from_reference (arg3);
5121 arg3_type = TREE_TYPE (arg3);
5122 if (error_operand_p (arg3))
5123 result = error_mark_node;
5127 /* Free all the conversions we allocated. */
5128 obstack_free (&conversion_obstack, p);
5133 /* If, after the conversion, both operands have class type,
5134 treat the cv-qualification of both operands as if it were the
5135 union of the cv-qualification of the operands.
5137 The standard is not clear about what to do in this
5138 circumstance. For example, if the first operand has type
5139 "const X" and the second operand has a user-defined
5140 conversion to "volatile X", what is the type of the second
5141 operand after this step? Making it be "const X" (matching
5142 the first operand) seems wrong, as that discards the
5143 qualification without actually performing a copy. Leaving it
5144 as "volatile X" seems wrong as that will result in the
5145 conditional expression failing altogether, even though,
5146 according to this step, the one operand could be converted to
5147 the type of the other. */
5149 && CLASS_TYPE_P (arg2_type)
5150 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
5151 arg2_type = arg3_type =
5152 cp_build_qualified_type (arg2_type,
5153 cp_type_quals (arg2_type)
5154 | cp_type_quals (arg3_type));
5159 If the second and third operands are glvalues of the same value
5160 category and have the same type, the result is of that type and
5162 if (((lvalue_p (arg2) && lvalue_p (arg3))
5163 || (xvalue_p (arg2) && xvalue_p (arg3)))
5164 && same_type_p (arg2_type, arg3_type))
5166 result_type = arg2_type;
5167 if (processing_template_decl)
5168 /* Let lvalue_kind know this was a glvalue. */
5169 result_type = cp_build_reference_type (result_type, xvalue_p (arg2));
5171 arg2 = mark_lvalue_use (arg2);
5172 arg3 = mark_lvalue_use (arg3);
5173 goto valid_operands;
5178 Otherwise, the result is an rvalue. If the second and third
5179 operand do not have the same type, and either has (possibly
5180 cv-qualified) class type, overload resolution is used to
5181 determine the conversions (if any) to be applied to the operands
5182 (_over.match.oper_, _over.built_). */
5184 if (!same_type_p (arg2_type, arg3_type)
5185 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
5191 /* Rearrange the arguments so that add_builtin_candidate only has
5192 to know about two args. In build_builtin_candidate, the
5193 arguments are unscrambled. */
5197 add_builtin_candidates (&candidates,
5200 ovl_op_identifier (false, COND_EXPR),
5202 LOOKUP_NORMAL, complain);
5206 If the overload resolution fails, the program is
5208 candidates = splice_viable (candidates, false, &any_viable_p);
5211 if (complain & tf_error)
5212 error_at (loc, "operands to ?: have different types %qT and %qT",
5213 arg2_type, arg3_type);
5214 return error_mark_node;
5216 cand = tourney (candidates, complain);
5219 if (complain & tf_error)
5221 op_error (loc, COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
5222 print_z_candidates (loc, candidates);
5224 return error_mark_node;
5229 Otherwise, the conversions thus determined are applied, and
5230 the converted operands are used in place of the original
5231 operands for the remainder of this section. */
5232 conv = cand->convs[0];
5233 arg1 = convert_like (conv, arg1, complain);
5234 conv = cand->convs[1];
5235 arg2 = convert_like (conv, arg2, complain);
5236 arg2_type = TREE_TYPE (arg2);
5237 conv = cand->convs[2];
5238 arg3 = convert_like (conv, arg3, complain);
5239 arg3_type = TREE_TYPE (arg3);
5244 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
5245 and function-to-pointer (_conv.func_) standard conversions are
5246 performed on the second and third operands.
5248 We need to force the lvalue-to-rvalue conversion here for class types,
5249 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
5250 that isn't wrapped with a TARGET_EXPR plays havoc with exception
5253 arg2 = force_rvalue (arg2, complain);
5254 if (!CLASS_TYPE_P (arg2_type))
5255 arg2_type = TREE_TYPE (arg2);
5257 arg3 = force_rvalue (arg3, complain);
5258 if (!CLASS_TYPE_P (arg3_type))
5259 arg3_type = TREE_TYPE (arg3);
5261 if (arg2 == error_mark_node || arg3 == error_mark_node)
5262 return error_mark_node;
5266 After those conversions, one of the following shall hold:
5268 --The second and third operands have the same type; the result is of
5270 if (same_type_p (arg2_type, arg3_type))
5271 result_type = arg2_type;
5274 --The second and third operands have arithmetic or enumeration
5275 type; the usual arithmetic conversions are performed to bring
5276 them to a common type, and the result is of that type. */
5277 else if ((ARITHMETIC_TYPE_P (arg2_type)
5278 || UNSCOPED_ENUM_P (arg2_type))
5279 && (ARITHMETIC_TYPE_P (arg3_type)
5280 || UNSCOPED_ENUM_P (arg3_type)))
5282 /* In this case, there is always a common type. */
5283 result_type = type_after_usual_arithmetic_conversions (arg2_type,
5285 if (complain & tf_warning)
5286 do_warn_double_promotion (result_type, arg2_type, arg3_type,
5287 "implicit conversion from %qH to %qI to "
5288 "match other result of conditional",
5291 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
5292 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
5294 if (TREE_CODE (orig_arg2) == CONST_DECL
5295 && TREE_CODE (orig_arg3) == CONST_DECL
5296 && DECL_CONTEXT (orig_arg2) == DECL_CONTEXT (orig_arg3))
5297 /* Two enumerators from the same enumeration can have different
5298 types when the enumeration is still being defined. */;
5299 else if (complain & tf_warning)
5300 warning_at (loc, OPT_Wenum_compare, "enumeral mismatch in "
5301 "conditional expression: %qT vs %qT",
5302 arg2_type, arg3_type);
5304 else if (extra_warnings
5305 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
5306 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
5307 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
5308 && !same_type_p (arg2_type,
5309 type_promotes_to (arg3_type)))))
5311 if (complain & tf_warning)
5312 warning_at (loc, OPT_Wextra, "enumeral and non-enumeral type in "
5313 "conditional expression");
5316 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5317 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5321 --The second and third operands have pointer type, or one has
5322 pointer type and the other is a null pointer constant; pointer
5323 conversions (_conv.ptr_) and qualification conversions
5324 (_conv.qual_) are performed to bring them to their composite
5325 pointer type (_expr.rel_). The result is of the composite
5328 --The second and third operands have pointer to member type, or
5329 one has pointer to member type and the other is a null pointer
5330 constant; pointer to member conversions (_conv.mem_) and
5331 qualification conversions (_conv.qual_) are performed to bring
5332 them to a common type, whose cv-qualification shall match the
5333 cv-qualification of either the second or the third operand.
5334 The result is of the common type. */
5335 else if ((null_ptr_cst_p (arg2)
5336 && TYPE_PTR_OR_PTRMEM_P (arg3_type))
5337 || (null_ptr_cst_p (arg3)
5338 && TYPE_PTR_OR_PTRMEM_P (arg2_type))
5339 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
5340 || (TYPE_PTRDATAMEM_P (arg2_type) && TYPE_PTRDATAMEM_P (arg3_type))
5341 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
5343 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
5344 arg3, CPO_CONDITIONAL_EXPR,
5346 if (result_type == error_mark_node)
5347 return error_mark_node;
5348 arg2 = perform_implicit_conversion (result_type, arg2, complain);
5349 arg3 = perform_implicit_conversion (result_type, arg3, complain);
5354 if (complain & tf_error)
5355 error_at (loc, "operands to ?: have different types %qT and %qT",
5356 arg2_type, arg3_type);
5357 return error_mark_node;
5360 if (arg2 == error_mark_node || arg3 == error_mark_node)
5361 return error_mark_node;
5364 result = build3_loc (loc, COND_EXPR, result_type, arg1, arg2, arg3);
5366 /* If the ARG2 and ARG3 are the same and don't have side-effects,
5367 warn here, because the COND_EXPR will be turned into ARG2. */
5368 if (warn_duplicated_branches
5369 && (complain & tf_warning)
5370 && (arg2 == arg3 || operand_equal_p (arg2, arg3, 0)))
5371 warning_at (EXPR_LOCATION (result), OPT_Wduplicated_branches,
5372 "this condition has identical branches");
5374 /* We can't use result_type below, as fold might have returned a
5379 /* Expand both sides into the same slot, hopefully the target of
5380 the ?: expression. We used to check for TARGET_EXPRs here,
5381 but now we sometimes wrap them in NOP_EXPRs so the test would
5383 if (CLASS_TYPE_P (TREE_TYPE (result)))
5384 result = get_target_expr_sfinae (result, complain);
5385 /* If this expression is an rvalue, but might be mistaken for an
5386 lvalue, we must add a NON_LVALUE_EXPR. */
5387 result = rvalue (result);
5390 result = force_paren_expr (result);
5395 /* Wrapper for above. */
5398 build_conditional_expr (location_t loc, tree arg1, tree arg2, tree arg3,
5399 tsubst_flags_t complain)
5402 bool subtime = timevar_cond_start (TV_OVERLOAD);
5403 ret = build_conditional_expr_1 (loc, arg1, arg2, arg3, complain);
5404 timevar_cond_stop (TV_OVERLOAD, subtime);
5408 /* OPERAND is an operand to an expression. Perform necessary steps
5409 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
5413 prep_operand (tree operand)
5417 if (CLASS_TYPE_P (TREE_TYPE (operand))
5418 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
5419 /* Make sure the template type is instantiated now. */
5420 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
5426 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
5427 OVERLOAD) to the CANDIDATES, returning an updated list of
5428 CANDIDATES. The ARGS are the arguments provided to the call;
5429 if FIRST_ARG is non-null it is the implicit object argument,
5430 otherwise the first element of ARGS is used if needed. The
5431 EXPLICIT_TARGS are explicit template arguments provided.
5432 TEMPLATE_ONLY is true if only template functions should be
5433 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
5434 add_function_candidate. */
5437 add_candidates (tree fns, tree first_arg, const vec<tree, va_gc> *args,
5439 tree explicit_targs, bool template_only,
5440 tree conversion_path, tree access_path,
5442 struct z_candidate **candidates,
5443 tsubst_flags_t complain)
5446 const vec<tree, va_gc> *non_static_args;
5447 bool check_list_ctor = false;
5448 bool check_converting = false;
5449 unification_kind_t strict;
5454 /* Precalculate special handling of constructors and conversion ops. */
5455 tree fn = OVL_FIRST (fns);
5456 if (DECL_CONV_FN_P (fn))
5458 check_list_ctor = false;
5459 check_converting = (flags & LOOKUP_ONLYCONVERTING) != 0;
5460 if (flags & LOOKUP_NO_CONVERSION)
5461 /* We're doing return_type(x). */
5462 strict = DEDUCE_CONV;
5464 /* We're doing x.operator return_type(). */
5465 strict = DEDUCE_EXACT;
5466 /* [over.match.funcs] For conversion functions, the function
5467 is considered to be a member of the class of the implicit
5468 object argument for the purpose of defining the type of
5469 the implicit object parameter. */
5470 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (first_arg));
5474 if (DECL_CONSTRUCTOR_P (fn))
5476 check_list_ctor = (flags & LOOKUP_LIST_ONLY) != 0;
5477 /* For list-initialization we consider explicit constructors
5478 and complain if one is chosen. */
5480 = ((flags & (LOOKUP_ONLYCONVERTING|LOOKUP_LIST_INIT_CTOR))
5481 == LOOKUP_ONLYCONVERTING);
5483 strict = DEDUCE_CALL;
5484 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
5488 non_static_args = args;
5490 /* Delay creating the implicit this parameter until it is needed. */
5491 non_static_args = NULL;
5493 for (lkp_iterator iter (fns); iter; ++iter)
5497 if (check_converting && DECL_NONCONVERTING_P (fn))
5499 if (check_list_ctor && !is_list_ctor (fn))
5502 tree fn_first_arg = NULL_TREE;
5503 const vec<tree, va_gc> *fn_args = args;
5505 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
5507 /* Figure out where the object arg comes from. If this
5508 function is a non-static member and we didn't get an
5509 implicit object argument, move it out of args. */
5510 if (first_arg == NULL_TREE)
5514 vec<tree, va_gc> *tempvec;
5515 vec_alloc (tempvec, args->length () - 1);
5516 for (ix = 1; args->iterate (ix, &arg); ++ix)
5517 tempvec->quick_push (arg);
5518 non_static_args = tempvec;
5519 first_arg = (*args)[0];
5522 fn_first_arg = first_arg;
5523 fn_args = non_static_args;
5526 if (TREE_CODE (fn) == TEMPLATE_DECL)
5527 add_template_candidate (candidates,
5539 else if (!template_only)
5540 add_function_candidate (candidates,
5552 /* Returns 1 if P0145R2 says that the LHS of operator CODE is evaluated first,
5553 -1 if the RHS is evaluated first, or 0 if the order is unspecified. */
5556 op_is_ordered (tree_code code)
5562 return (flag_strong_eval_order > 1 ? -1 : 0);
5566 return (flag_strong_eval_order > 1 ? 1 : 0);
5569 // Not overloadable (yet).
5571 // Only one argument.
5578 return (flag_strong_eval_order ? 1 : 0);
5586 build_new_op_1 (location_t loc, enum tree_code code, int flags, tree arg1,
5587 tree arg2, tree arg3, tree *overload, tsubst_flags_t complain)
5589 struct z_candidate *candidates = 0, *cand;
5590 vec<tree, va_gc> *arglist;
5592 tree result = NULL_TREE;
5593 bool result_valid_p = false;
5594 enum tree_code code2 = NOP_EXPR;
5595 enum tree_code code_orig_arg1 = ERROR_MARK;
5596 enum tree_code code_orig_arg2 = ERROR_MARK;
5602 if (error_operand_p (arg1)
5603 || error_operand_p (arg2)
5604 || error_operand_p (arg3))
5605 return error_mark_node;
5607 bool ismodop = code == MODIFY_EXPR;
5610 code2 = TREE_CODE (arg3);
5613 tree fnname = ovl_op_identifier (ismodop, ismodop ? code2 : code);
5615 arg1 = prep_operand (arg1);
5617 bool memonly = false;
5622 case VEC_DELETE_EXPR:
5624 /* Use build_op_new_call and build_op_delete_call instead. */
5628 /* Use build_op_call instead. */
5631 case TRUTH_ORIF_EXPR:
5632 case TRUTH_ANDIF_EXPR:
5633 case TRUTH_AND_EXPR:
5635 /* These are saved for the sake of warn_logical_operator. */
5636 code_orig_arg1 = TREE_CODE (arg1);
5637 code_orig_arg2 = TREE_CODE (arg2);
5645 /* These are saved for the sake of maybe_warn_bool_compare. */
5646 code_orig_arg1 = TREE_CODE (TREE_TYPE (arg1));
5647 code_orig_arg2 = TREE_CODE (TREE_TYPE (arg2));
5650 /* =, ->, [], () must be non-static member functions. */
5652 if (code2 != NOP_EXPR)
5664 arg2 = prep_operand (arg2);
5665 arg3 = prep_operand (arg3);
5667 if (code == COND_EXPR)
5668 /* Use build_conditional_expr instead. */
5670 else if (! OVERLOAD_TYPE_P (TREE_TYPE (arg1))
5671 && (! arg2 || ! OVERLOAD_TYPE_P (TREE_TYPE (arg2))))
5674 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
5675 arg2 = integer_zero_node;
5677 vec_alloc (arglist, 3);
5678 arglist->quick_push (arg1);
5679 if (arg2 != NULL_TREE)
5680 arglist->quick_push (arg2);
5681 if (arg3 != NULL_TREE)
5682 arglist->quick_push (arg3);
5684 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5685 p = conversion_obstack_alloc (0);
5687 /* Add namespace-scope operators to the list of functions to
5691 tree fns = lookup_name_real (fnname, 0, 1, /*block_p=*/true, 0, 0);
5692 fns = lookup_arg_dependent (fnname, fns, arglist);
5693 add_candidates (fns, NULL_TREE, arglist, NULL_TREE,
5694 NULL_TREE, false, NULL_TREE, NULL_TREE,
5695 flags, &candidates, complain);
5700 args[2] = NULL_TREE;
5702 /* Add class-member operators to the candidate set. */
5703 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
5707 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
5708 if (fns == error_mark_node)
5710 result = error_mark_node;
5711 goto user_defined_result_ready;
5714 add_candidates (BASELINK_FUNCTIONS (fns),
5715 NULL_TREE, arglist, NULL_TREE,
5717 BASELINK_BINFO (fns),
5718 BASELINK_ACCESS_BINFO (fns),
5719 flags, &candidates, complain);
5721 /* Per 13.3.1.2/3, 2nd bullet, if no operand has a class type, then
5722 only non-member functions that have type T1 or reference to
5723 cv-qualified-opt T1 for the first argument, if the first argument
5724 has an enumeration type, or T2 or reference to cv-qualified-opt
5725 T2 for the second argument, if the second argument has an
5726 enumeration type. Filter out those that don't match. */
5727 else if (! arg2 || ! CLASS_TYPE_P (TREE_TYPE (arg2)))
5729 struct z_candidate **candp, **next;
5731 for (candp = &candidates; *candp; candp = next)
5733 tree parmlist, parmtype;
5734 int i, nargs = (arg2 ? 2 : 1);
5739 parmlist = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
5741 for (i = 0; i < nargs; ++i)
5743 parmtype = TREE_VALUE (parmlist);
5745 if (TREE_CODE (parmtype) == REFERENCE_TYPE)
5746 parmtype = TREE_TYPE (parmtype);
5747 if (TREE_CODE (TREE_TYPE (args[i])) == ENUMERAL_TYPE
5748 && (same_type_ignoring_top_level_qualifiers_p
5749 (TREE_TYPE (args[i]), parmtype)))
5752 parmlist = TREE_CHAIN (parmlist);
5755 /* No argument has an appropriate type, so remove this
5756 candidate function from the list. */
5759 *candp = cand->next;
5765 add_builtin_candidates (&candidates, code, code2, fnname, args,
5772 /* For these, the built-in candidates set is empty
5773 [over.match.oper]/3. We don't want non-strict matches
5774 because exact matches are always possible with built-in
5775 operators. The built-in candidate set for COMPONENT_REF
5776 would be empty too, but since there are no such built-in
5777 operators, we accept non-strict matches for them. */
5786 candidates = splice_viable (candidates, strict_p, &any_viable_p);
5791 case POSTINCREMENT_EXPR:
5792 case POSTDECREMENT_EXPR:
5793 /* Don't try anything fancy if we're not allowed to produce
5795 if (!(complain & tf_error))
5796 return error_mark_node;
5798 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
5799 distinguish between prefix and postfix ++ and
5800 operator++() was used for both, so we allow this with
5804 const char *msg = (flag_permissive)
5805 ? G_("no %<%D(int)%> declared for postfix %qs,"
5806 " trying prefix operator instead")
5807 : G_("no %<%D(int)%> declared for postfix %qs");
5808 permerror (loc, msg, fnname, OVL_OP_INFO (false, code)->name);
5811 if (!flag_permissive)
5812 return error_mark_node;
5814 if (code == POSTINCREMENT_EXPR)
5815 code = PREINCREMENT_EXPR;
5817 code = PREDECREMENT_EXPR;
5818 result = build_new_op_1 (loc, code, flags, arg1, NULL_TREE,
5819 NULL_TREE, overload, complain);
5822 /* The caller will deal with these. */
5827 result_valid_p = true;
5831 if (complain & tf_error)
5833 /* If one of the arguments of the operator represents
5834 an invalid use of member function pointer, try to report
5835 a meaningful error ... */
5836 if (invalid_nonstatic_memfn_p (loc, arg1, tf_error)
5837 || invalid_nonstatic_memfn_p (loc, arg2, tf_error)
5838 || invalid_nonstatic_memfn_p (loc, arg3, tf_error))
5839 /* We displayed the error message. */;
5842 /* ... Otherwise, report the more generic
5843 "no matching operator found" error */
5844 op_error (loc, code, code2, arg1, arg2, arg3, FALSE);
5845 print_z_candidates (loc, candidates);
5848 result = error_mark_node;
5854 cand = tourney (candidates, complain);
5857 if (complain & tf_error)
5859 op_error (loc, code, code2, arg1, arg2, arg3, TRUE);
5860 print_z_candidates (loc, candidates);
5862 result = error_mark_node;
5864 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
5867 *overload = cand->fn;
5869 if (resolve_args (arglist, complain) == NULL)
5870 result = error_mark_node;
5872 result = build_over_call (cand, LOOKUP_NORMAL, complain);
5874 if (trivial_fn_p (cand->fn))
5875 /* There won't be a CALL_EXPR. */;
5876 else if (result && result != error_mark_node)
5878 tree call = extract_call_expr (result);
5879 CALL_EXPR_OPERATOR_SYNTAX (call) = true;
5881 if (processing_template_decl && DECL_HIDDEN_FRIEND_P (cand->fn))
5882 /* This prevents build_new_function_call from discarding this
5883 function during instantiation of the enclosing template. */
5884 KOENIG_LOOKUP_P (call) = 1;
5886 /* Specify evaluation order as per P0145R2. */
5887 CALL_EXPR_ORDERED_ARGS (call) = false;
5888 switch (op_is_ordered (code))
5891 CALL_EXPR_REVERSE_ARGS (call) = true;
5895 CALL_EXPR_ORDERED_ARGS (call) = true;
5905 /* Give any warnings we noticed during overload resolution. */
5906 if (cand->warnings && (complain & tf_warning))
5908 struct candidate_warning *w;
5909 for (w = cand->warnings; w; w = w->next)
5910 joust (cand, w->loser, 1, complain);
5913 /* Check for comparison of different enum types. */
5922 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
5923 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
5924 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
5925 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
5926 && (complain & tf_warning))
5928 warning (OPT_Wenum_compare,
5929 "comparison between %q#T and %q#T",
5930 TREE_TYPE (arg1), TREE_TYPE (arg2));
5937 /* We need to strip any leading REF_BIND so that bitfields
5938 don't cause errors. This should not remove any important
5939 conversions, because builtins don't apply to class
5940 objects directly. */
5941 conv = cand->convs[0];
5942 if (conv->kind == ck_ref_bind)
5943 conv = next_conversion (conv);
5944 arg1 = convert_like (conv, arg1, complain);
5948 conv = cand->convs[1];
5949 if (conv->kind == ck_ref_bind)
5950 conv = next_conversion (conv);
5952 arg2 = decay_conversion (arg2, complain);
5954 /* We need to call warn_logical_operator before
5955 converting arg2 to a boolean_type, but after
5956 decaying an enumerator to its value. */
5957 if (complain & tf_warning)
5958 warn_logical_operator (loc, code, boolean_type_node,
5959 code_orig_arg1, arg1,
5960 code_orig_arg2, arg2);
5962 arg2 = convert_like (conv, arg2, complain);
5966 conv = cand->convs[2];
5967 if (conv->kind == ck_ref_bind)
5968 conv = next_conversion (conv);
5969 arg3 = convert_like (conv, arg3, complain);
5975 user_defined_result_ready:
5977 /* Free all the conversions we allocated. */
5978 obstack_free (&conversion_obstack, p);
5980 if (result || result_valid_p)
5987 return cp_build_modify_expr (loc, arg1, code2, arg2, complain);
5990 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
5992 case TRUTH_ANDIF_EXPR:
5993 case TRUTH_ORIF_EXPR:
5994 case TRUTH_AND_EXPR:
5996 if (complain & tf_warning)
5997 warn_logical_operator (loc, code, boolean_type_node,
5998 code_orig_arg1, arg1,
5999 code_orig_arg2, arg2);
6007 if ((complain & tf_warning)
6008 && ((code_orig_arg1 == BOOLEAN_TYPE)
6009 ^ (code_orig_arg2 == BOOLEAN_TYPE)))
6010 maybe_warn_bool_compare (loc, code, arg1, arg2);
6011 if (complain & tf_warning && warn_tautological_compare)
6012 warn_tautological_cmp (loc, code, arg1, arg2);
6017 case TRUNC_DIV_EXPR:
6022 case TRUNC_MOD_EXPR:
6026 return cp_build_binary_op (loc, code, arg1, arg2, complain);
6028 case UNARY_PLUS_EXPR:
6031 case TRUTH_NOT_EXPR:
6032 case PREINCREMENT_EXPR:
6033 case POSTINCREMENT_EXPR:
6034 case PREDECREMENT_EXPR:
6035 case POSTDECREMENT_EXPR:
6039 return cp_build_unary_op (code, arg1, candidates != 0, complain);
6042 return cp_build_array_ref (input_location, arg1, arg2, complain);
6045 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_ARROW_STAR,
6049 /* The caller will deal with these. */
6061 /* Wrapper for above. */
6064 build_new_op (location_t loc, enum tree_code code, int flags,
6065 tree arg1, tree arg2, tree arg3,
6066 tree *overload, tsubst_flags_t complain)
6069 bool subtime = timevar_cond_start (TV_OVERLOAD);
6070 ret = build_new_op_1 (loc, code, flags, arg1, arg2, arg3,
6071 overload, complain);
6072 timevar_cond_stop (TV_OVERLOAD, subtime);
6076 /* CALL was returned by some call-building function; extract the actual
6077 CALL_EXPR from any bits that have been tacked on, e.g. by
6078 convert_from_reference. */
6081 extract_call_expr (tree call)
6083 while (TREE_CODE (call) == COMPOUND_EXPR)
6084 call = TREE_OPERAND (call, 1);
6085 if (REFERENCE_REF_P (call))
6086 call = TREE_OPERAND (call, 0);
6087 if (TREE_CODE (call) == TARGET_EXPR)
6088 call = TARGET_EXPR_INITIAL (call);
6089 gcc_assert (TREE_CODE (call) == CALL_EXPR
6090 || TREE_CODE (call) == AGGR_INIT_EXPR
6091 || call == error_mark_node);
6095 /* Returns true if FN has two parameters, of which the second has type
6099 second_parm_is_size_t (tree fn)
6101 tree t = FUNCTION_ARG_CHAIN (fn);
6102 if (!t || !same_type_p (TREE_VALUE (t), size_type_node))
6105 if (t == void_list_node)
6107 if (aligned_new_threshold && t
6108 && same_type_p (TREE_VALUE (t), align_type_node)
6109 && TREE_CHAIN (t) == void_list_node)
6114 /* True if T, an allocation function, has std::align_val_t as its second
6118 aligned_allocation_fn_p (tree t)
6120 if (!aligned_new_threshold)
6123 tree a = FUNCTION_ARG_CHAIN (t);
6124 return (a && same_type_p (TREE_VALUE (a), align_type_node));
6127 /* Returns true iff T, an element of an OVERLOAD chain, is a usual deallocation
6128 function (3.7.4.2 [basic.stc.dynamic.deallocation]) with a parameter of
6129 std::align_val_t. */
6132 aligned_deallocation_fn_p (tree t)
6134 if (!aligned_new_threshold)
6137 /* A template instance is never a usual deallocation function,
6138 regardless of its signature. */
6139 if (TREE_CODE (t) == TEMPLATE_DECL
6140 || primary_template_specialization_p (t))
6143 tree a = FUNCTION_ARG_CHAIN (t);
6144 if (same_type_p (TREE_VALUE (a), align_type_node)
6145 && TREE_CHAIN (a) == void_list_node)
6147 if (!same_type_p (TREE_VALUE (a), size_type_node))
6150 if (a && same_type_p (TREE_VALUE (a), align_type_node)
6151 && TREE_CHAIN (a) == void_list_node)
6156 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
6157 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
6160 usual_deallocation_fn_p (tree t)
6162 /* A template instance is never a usual deallocation function,
6163 regardless of its signature. */
6164 if (TREE_CODE (t) == TEMPLATE_DECL
6165 || primary_template_specialization_p (t))
6168 /* If a class T has a member deallocation function named operator delete
6169 with exactly one parameter, then that function is a usual
6170 (non-placement) deallocation function. If class T does not declare
6171 such an operator delete but does declare a member deallocation
6172 function named operator delete with exactly two parameters, the second
6173 of which has type std::size_t (18.2), then this function is a usual
6174 deallocation function. */
6175 bool global = DECL_NAMESPACE_SCOPE_P (t);
6176 tree chain = FUNCTION_ARG_CHAIN (t);
6179 if (chain == void_list_node
6180 || ((!global || flag_sized_deallocation)
6181 && second_parm_is_size_t (t)))
6183 if (aligned_deallocation_fn_p (t))
6188 /* Build a call to operator delete. This has to be handled very specially,
6189 because the restrictions on what signatures match are different from all
6190 other call instances. For a normal delete, only a delete taking (void *)
6191 or (void *, size_t) is accepted. For a placement delete, only an exact
6192 match with the placement new is accepted.
6194 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
6195 ADDR is the pointer to be deleted.
6196 SIZE is the size of the memory block to be deleted.
6197 GLOBAL_P is true if the delete-expression should not consider
6198 class-specific delete operators.
6199 PLACEMENT is the corresponding placement new call, or NULL_TREE.
6201 If this call to "operator delete" is being generated as part to
6202 deallocate memory allocated via a new-expression (as per [expr.new]
6203 which requires that if the initialization throws an exception then
6204 we call a deallocation function), then ALLOC_FN is the allocation
6208 build_op_delete_call (enum tree_code code, tree addr, tree size,
6209 bool global_p, tree placement,
6210 tree alloc_fn, tsubst_flags_t complain)
6212 tree fn = NULL_TREE;
6213 tree fns, fnname, type, t;
6215 if (addr == error_mark_node)
6216 return error_mark_node;
6218 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
6220 fnname = ovl_op_identifier (false, code);
6222 if (CLASS_TYPE_P (type)
6223 && COMPLETE_TYPE_P (complete_type (type))
6227 If the result of the lookup is ambiguous or inaccessible, or if
6228 the lookup selects a placement deallocation function, the
6229 program is ill-formed.
6231 Therefore, we ask lookup_fnfields to complain about ambiguity. */
6233 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
6234 if (fns == error_mark_node)
6235 return error_mark_node;
6240 if (fns == NULL_TREE)
6241 fns = lookup_name_nonclass (fnname);
6243 /* Strip const and volatile from addr. */
6244 addr = cp_convert (ptr_type_node, addr, complain);
6248 /* "A declaration of a placement deallocation function matches the
6249 declaration of a placement allocation function if it has the same
6250 number of parameters and, after parameter transformations (8.3.5),
6251 all parameter types except the first are identical."
6253 So we build up the function type we want and ask instantiate_type
6254 to get it for us. */
6255 t = FUNCTION_ARG_CHAIN (alloc_fn);
6256 t = tree_cons (NULL_TREE, ptr_type_node, t);
6257 t = build_function_type (void_type_node, t);
6259 fn = instantiate_type (t, fns, tf_none);
6260 if (fn == error_mark_node)
6263 fn = MAYBE_BASELINK_FUNCTIONS (fn);
6265 /* "If the lookup finds the two-parameter form of a usual deallocation
6266 function (3.7.4.2) and that function, considered as a placement
6267 deallocation function, would have been selected as a match for the
6268 allocation function, the program is ill-formed." */
6269 if (second_parm_is_size_t (fn))
6271 const char *const msg1
6272 = G_("exception cleanup for this placement new selects "
6273 "non-placement operator delete");
6274 const char *const msg2
6275 = G_("%qD is a usual (non-placement) deallocation "
6276 "function in C++14 (or with -fsized-deallocation)");
6278 /* But if the class has an operator delete (void *), then that is
6279 the usual deallocation function, so we shouldn't complain
6280 about using the operator delete (void *, size_t). */
6281 if (DECL_CLASS_SCOPE_P (fn))
6282 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns));
6286 if (usual_deallocation_fn_p (elt)
6287 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
6290 /* Before C++14 a two-parameter global deallocation function is
6291 always a placement deallocation function, but warn if
6293 else if (!flag_sized_deallocation)
6295 if ((complain & tf_warning)
6296 && warning (OPT_Wc__14_compat, msg1))
6297 inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
6301 if (complain & tf_warning_or_error)
6303 if (permerror (input_location, msg1))
6305 /* Only mention C++14 for namespace-scope delete. */
6306 if (DECL_NAMESPACE_SCOPE_P (fn))
6307 inform (DECL_SOURCE_LOCATION (fn), msg2, fn);
6309 inform (DECL_SOURCE_LOCATION (fn),
6310 "%qD is a usual (non-placement) deallocation "
6315 return error_mark_node;
6320 /* "Any non-placement deallocation function matches a non-placement
6321 allocation function. If the lookup finds a single matching
6322 deallocation function, that function will be called; otherwise, no
6323 deallocation function will be called." */
6324 for (lkp_iterator iter (MAYBE_BASELINK_FUNCTIONS (fns)); iter; ++iter)
6327 if (usual_deallocation_fn_p (elt))
6335 /* -- If the type has new-extended alignment, a function with a
6336 parameter of type std::align_val_t is preferred; otherwise a
6337 function without such a parameter is preferred. If exactly one
6338 preferred function is found, that function is selected and the
6339 selection process terminates. If more than one preferred
6340 function is found, all non-preferred functions are eliminated
6341 from further consideration. */
6342 if (aligned_new_threshold)
6344 bool want_align = type_has_new_extended_alignment (type);
6345 bool fn_align = aligned_deallocation_fn_p (fn);
6346 bool elt_align = aligned_deallocation_fn_p (elt);
6348 if (elt_align != fn_align)
6350 if (want_align == elt_align)
6356 /* -- If the deallocation functions have class scope, the one
6357 without a parameter of type std::size_t is selected. */
6359 if (DECL_CLASS_SCOPE_P (fn))
6362 /* -- If the type is complete and if, for the second alternative
6363 (delete array) only, the operand is a pointer to a class type
6364 with a non-trivial destructor or a (possibly multi-dimensional)
6365 array thereof, the function with a parameter of type std::size_t
6368 -- Otherwise, it is unspecified whether a deallocation function
6369 with a parameter of type std::size_t is selected. */
6372 want_size = COMPLETE_TYPE_P (type);
6373 if (code == VEC_DELETE_EXPR
6374 && !TYPE_VEC_NEW_USES_COOKIE (type))
6375 /* We need a cookie to determine the array size. */
6378 bool fn_size = second_parm_is_size_t (fn);
6379 bool elt_size = second_parm_is_size_t (elt);
6380 gcc_assert (fn_size != elt_size);
6381 if (want_size == elt_size)
6386 /* If we have a matching function, call it. */
6389 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
6391 /* If the FN is a member function, make sure that it is
6393 if (BASELINK_P (fns))
6394 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn,
6397 /* Core issue 901: It's ok to new a type with deleted delete. */
6398 if (DECL_DELETED_FN (fn) && alloc_fn)
6403 /* The placement args might not be suitable for overload
6404 resolution at this point, so build the call directly. */
6405 int nargs = call_expr_nargs (placement);
6406 tree *argarray = XALLOCAVEC (tree, nargs);
6409 for (i = 1; i < nargs; i++)
6410 argarray[i] = CALL_EXPR_ARG (placement, i);
6411 if (!mark_used (fn, complain) && !(complain & tf_error))
6412 return error_mark_node;
6413 return build_cxx_call (fn, nargs, argarray, complain);
6418 vec<tree, va_gc> *args = make_tree_vector ();
6419 args->quick_push (addr);
6420 if (second_parm_is_size_t (fn))
6421 args->quick_push (size);
6422 if (aligned_deallocation_fn_p (fn))
6424 tree al = build_int_cst (align_type_node, TYPE_ALIGN_UNIT (type));
6425 args->quick_push (al);
6427 ret = cp_build_function_call_vec (fn, &args, complain);
6428 release_tree_vector (args);
6435 If no unambiguous matching deallocation function can be found,
6436 propagating the exception does not cause the object's memory to
6440 if ((complain & tf_warning)
6442 warning (0, "no corresponding deallocation function for %qD",
6447 if (complain & tf_error)
6448 error ("no suitable %<operator %s%> for %qT",
6449 OVL_OP_INFO (false, code)->name, type);
6450 return error_mark_node;
6453 /* If the current scope isn't allowed to access DECL along
6454 BASETYPE_PATH, give an error. The most derived class in
6455 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
6456 the declaration to use in the error diagnostic. */
6459 enforce_access (tree basetype_path, tree decl, tree diag_decl,
6460 tsubst_flags_t complain, access_failure_info *afi)
6462 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
6464 if (flag_new_inheriting_ctors
6465 && DECL_INHERITED_CTOR (decl))
6467 /* 7.3.3/18: The additional constructors are accessible if they would be
6468 accessible when used to construct an object of the corresponding base
6470 decl = strip_inheriting_ctors (decl);
6471 basetype_path = lookup_base (basetype_path, DECL_CONTEXT (decl),
6472 ba_any, NULL, complain);
6475 if (!accessible_p (basetype_path, decl, true))
6477 if (complain & tf_error)
6479 if (flag_new_inheriting_ctors)
6480 diag_decl = strip_inheriting_ctors (diag_decl);
6481 if (TREE_PRIVATE (decl))
6483 error ("%q#D is private within this context", diag_decl);
6484 inform (DECL_SOURCE_LOCATION (diag_decl),
6485 "declared private here");
6487 afi->record_access_failure (basetype_path, diag_decl);
6489 else if (TREE_PROTECTED (decl))
6491 error ("%q#D is protected within this context", diag_decl);
6492 inform (DECL_SOURCE_LOCATION (diag_decl),
6493 "declared protected here");
6495 afi->record_access_failure (basetype_path, diag_decl);
6499 error ("%q#D is inaccessible within this context", diag_decl);
6500 inform (DECL_SOURCE_LOCATION (diag_decl), "declared here");
6502 afi->record_access_failure (basetype_path, diag_decl);
6511 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
6512 bitwise or of LOOKUP_* values. If any errors are warnings are
6513 generated, set *DIAGNOSTIC_FN to "error" or "warning",
6514 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
6518 build_temp (tree expr, tree type, int flags,
6519 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
6522 vec<tree, va_gc> *args;
6524 *diagnostic_kind = DK_UNSPECIFIED;
6526 /* If the source is a packed field, calling the copy constructor will require
6527 binding the field to the reference parameter to the copy constructor, and
6528 we'll end up with an infinite loop. If we can use a bitwise copy, then
6530 if ((lvalue_kind (expr) & clk_packed)
6531 && CLASS_TYPE_P (TREE_TYPE (expr))
6532 && !type_has_nontrivial_copy_init (TREE_TYPE (expr)))
6533 return get_target_expr_sfinae (expr, complain);
6535 savew = warningcount + werrorcount, savee = errorcount;
6536 args = make_tree_vector_single (expr);
6537 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6538 &args, type, flags, complain);
6539 release_tree_vector (args);
6540 if (warningcount + werrorcount > savew)
6541 *diagnostic_kind = DK_WARNING;
6542 else if (errorcount > savee)
6543 *diagnostic_kind = DK_ERROR;
6547 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
6548 EXPR is implicitly converted to type TOTYPE.
6549 FN and ARGNUM are used for diagnostics. */
6552 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
6554 /* Issue warnings about peculiar, but valid, uses of NULL. */
6555 if (null_node_p (expr) && TREE_CODE (totype) != BOOLEAN_TYPE
6556 && ARITHMETIC_TYPE_P (totype))
6558 source_location loc =
6559 expansion_point_location_if_in_system_header (input_location);
6562 warning_at (loc, OPT_Wconversion_null,
6563 "passing NULL to non-pointer argument %P of %qD",
6566 warning_at (loc, OPT_Wconversion_null,
6567 "converting to non-pointer type %qT from NULL", totype);
6570 /* Issue warnings if "false" is converted to a NULL pointer */
6571 else if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE
6572 && TYPE_PTR_P (totype))
6575 warning_at (input_location, OPT_Wconversion_null,
6576 "converting %<false%> to pointer type for argument %P "
6577 "of %qD", argnum, fn);
6579 warning_at (input_location, OPT_Wconversion_null,
6580 "converting %<false%> to pointer type %qT", totype);
6584 /* We gave a diagnostic during a conversion. If this was in the second
6585 standard conversion sequence of a user-defined conversion sequence, say
6586 which user-defined conversion. */
6589 maybe_print_user_conv_context (conversion *convs)
6591 if (convs->user_conv_p)
6592 for (conversion *t = convs; t; t = next_conversion (t))
6593 if (t->kind == ck_user)
6595 print_z_candidate (0, " after user-defined conversion:",
6601 /* Locate the parameter with the given index within FNDECL.
6602 ARGNUM is zero based, -1 indicates the `this' argument of a method.
6603 Return the location of the FNDECL itself if there are problems. */
6606 get_fndecl_argument_location (tree fndecl, int argnum)
6611 /* Locate param by index within DECL_ARGUMENTS (fndecl). */
6612 for (i = 0, param = FUNCTION_FIRST_USER_PARM (fndecl);
6613 i < argnum && param;
6614 i++, param = TREE_CHAIN (param))
6617 /* If something went wrong (e.g. if we have a builtin and thus no arguments),
6618 return the location of FNDECL. */
6620 return DECL_SOURCE_LOCATION (fndecl);
6622 return DECL_SOURCE_LOCATION (param);
6625 /* Perform the conversions in CONVS on the expression EXPR. FN and
6626 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
6627 indicates the `this' argument of a method. INNER is nonzero when
6628 being called to continue a conversion chain. It is negative when a
6629 reference binding will be applied, positive otherwise. If
6630 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
6631 conversions will be emitted if appropriate. If C_CAST_P is true,
6632 this conversion is coming from a C-style cast; in that case,
6633 conversions to inaccessible bases are permitted. */
6636 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
6637 bool issue_conversion_warnings,
6638 bool c_cast_p, tsubst_flags_t complain)
6640 tree totype = convs->type;
6641 diagnostic_t diag_kind;
6643 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
6645 if (convs->bad_p && !(complain & tf_error))
6646 return error_mark_node;
6649 && convs->kind != ck_user
6650 && convs->kind != ck_list
6651 && convs->kind != ck_ambig
6652 && (convs->kind != ck_ref_bind
6653 || (convs->user_conv_p && next_conversion (convs)->bad_p))
6654 && (convs->kind != ck_rvalue
6655 || SCALAR_TYPE_P (totype))
6656 && convs->kind != ck_base)
6658 bool complained = false;
6659 conversion *t = convs;
6661 /* Give a helpful error if this is bad because of excess braces. */
6662 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
6663 && SCALAR_TYPE_P (totype)
6664 && CONSTRUCTOR_NELTS (expr) > 0
6665 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
6667 complained = permerror (loc, "too many braces around initializer "
6669 while (BRACE_ENCLOSED_INITIALIZER_P (expr)
6670 && CONSTRUCTOR_NELTS (expr) == 1)
6671 expr = CONSTRUCTOR_ELT (expr, 0)->value;
6674 /* Give a helpful error if this is bad because a conversion to bool
6675 from std::nullptr_t requires direct-initialization. */
6676 if (NULLPTR_TYPE_P (TREE_TYPE (expr))
6677 && TREE_CODE (totype) == BOOLEAN_TYPE)
6678 complained = permerror (loc, "converting to %qH from %qI requires "
6679 "direct-initialization",
6680 totype, TREE_TYPE (expr));
6682 for (; t ; t = next_conversion (t))
6684 if (t->kind == ck_user && t->cand->reason)
6686 complained = permerror (loc, "invalid user-defined conversion "
6687 "from %qH to %qI", TREE_TYPE (expr),
6690 print_z_candidate (loc, "candidate is:", t->cand);
6691 expr = convert_like_real (t, expr, fn, argnum,
6692 /*issue_conversion_warnings=*/false,
6695 if (convs->kind == ck_ref_bind)
6696 expr = convert_to_reference (totype, expr, CONV_IMPLICIT,
6697 LOOKUP_NORMAL, NULL_TREE,
6700 expr = cp_convert (totype, expr, complain);
6701 if (complained && fn)
6702 inform (DECL_SOURCE_LOCATION (fn),
6703 " initializing argument %P of %qD", argnum, fn);
6706 else if (t->kind == ck_user || !t->bad_p)
6708 expr = convert_like_real (t, expr, fn, argnum,
6709 /*issue_conversion_warnings=*/false,
6714 else if (t->kind == ck_ambig)
6715 return convert_like_real (t, expr, fn, argnum,
6716 /*issue_conversion_warnings=*/false,
6719 else if (t->kind == ck_identity)
6723 complained = permerror (loc, "invalid conversion from %qH to %qI",
6724 TREE_TYPE (expr), totype);
6725 if (complained && fn)
6726 inform (get_fndecl_argument_location (fn, argnum),
6727 " initializing argument %P of %qD", argnum, fn);
6729 return cp_convert (totype, expr, complain);
6732 if (issue_conversion_warnings && (complain & tf_warning))
6733 conversion_null_warnings (totype, expr, fn, argnum);
6735 switch (convs->kind)
6739 struct z_candidate *cand = convs->cand;
6742 /* We chose the surrogate function from add_conv_candidate, now we
6743 actually need to build the conversion. */
6744 cand = build_user_type_conversion_1 (totype, expr,
6745 LOOKUP_NO_CONVERSION, complain);
6747 tree convfn = cand->fn;
6749 /* When converting from an init list we consider explicit
6750 constructors, but actually trying to call one is an error. */
6751 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
6752 && BRACE_ENCLOSED_INITIALIZER_P (expr)
6753 /* Unless this is for direct-list-initialization. */
6754 && !CONSTRUCTOR_IS_DIRECT_INIT (expr)
6755 /* And in C++98 a default constructor can't be explicit. */
6756 && cxx_dialect >= cxx11)
6758 if (!(complain & tf_error))
6759 return error_mark_node;
6760 location_t loc = location_of (expr);
6761 if (CONSTRUCTOR_NELTS (expr) == 0
6762 && FUNCTION_FIRST_USER_PARMTYPE (convfn) != void_list_node)
6764 if (pedwarn (loc, 0, "converting to %qT from initializer list "
6765 "would use explicit constructor %qD",
6767 inform (loc, "in C++11 and above a default constructor "
6771 error ("converting to %qT from initializer list would use "
6772 "explicit constructor %qD", totype, convfn);
6775 /* If we're initializing from {}, it's value-initialization. */
6776 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
6777 && CONSTRUCTOR_NELTS (expr) == 0
6778 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
6780 bool direct = CONSTRUCTOR_IS_DIRECT_INIT (expr);
6781 if (abstract_virtuals_error_sfinae (NULL_TREE, totype, complain))
6782 return error_mark_node;
6783 expr = build_value_init (totype, complain);
6784 expr = get_target_expr_sfinae (expr, complain);
6785 if (expr != error_mark_node)
6787 TARGET_EXPR_LIST_INIT_P (expr) = true;
6788 TARGET_EXPR_DIRECT_INIT_P (expr) = direct;
6793 /* We don't know here whether EXPR is being used as an lvalue or
6794 rvalue, but we know it's read. */
6795 mark_exp_read (expr);
6797 /* Pass LOOKUP_NO_CONVERSION so rvalue/base handling knows not to allow
6799 expr = build_over_call (cand, LOOKUP_NORMAL|LOOKUP_NO_CONVERSION,
6802 /* If this is a constructor or a function returning an aggr type,
6803 we need to build up a TARGET_EXPR. */
6804 if (DECL_CONSTRUCTOR_P (convfn))
6806 expr = build_cplus_new (totype, expr, complain);
6808 /* Remember that this was list-initialization. */
6809 if (convs->check_narrowing && expr != error_mark_node)
6810 TARGET_EXPR_LIST_INIT_P (expr) = true;
6816 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
6818 int nelts = CONSTRUCTOR_NELTS (expr);
6820 expr = build_value_init (totype, complain);
6821 else if (nelts == 1)
6822 expr = CONSTRUCTOR_ELT (expr, 0)->value;
6826 expr = mark_use (expr, /*rvalue_p=*/!convs->rvaluedness_matches_p,
6827 /*read_p=*/true, UNKNOWN_LOCATION,
6828 /*reject_builtin=*/true);
6830 if (type_unknown_p (expr))
6831 expr = instantiate_type (totype, expr, complain);
6832 if (expr == null_node
6833 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
6834 /* If __null has been converted to an integer type, we do not want to
6835 continue to warn about uses of EXPR as an integer, rather than as a
6837 expr = build_int_cst (totype, 0);
6840 /* We leave bad_p off ck_ambig because overload resolution considers
6841 it valid, it just fails when we try to perform it. So we need to
6842 check complain here, too. */
6843 if (complain & tf_error)
6845 /* Call build_user_type_conversion again for the error. */
6846 int flags = (convs->need_temporary_p
6847 ? LOOKUP_IMPLICIT : LOOKUP_NORMAL);
6848 build_user_type_conversion (totype, convs->u.expr, flags, complain);
6849 gcc_assert (seen_error ());
6851 inform (DECL_SOURCE_LOCATION (fn),
6852 " initializing argument %P of %qD", argnum, fn);
6854 return error_mark_node;
6858 /* Conversion to std::initializer_list<T>. */
6859 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
6860 tree new_ctor = build_constructor (init_list_type_node, NULL);
6861 unsigned len = CONSTRUCTOR_NELTS (expr);
6862 tree array, val, field;
6863 vec<constructor_elt, va_gc> *vec = NULL;
6866 /* Convert all the elements. */
6867 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
6869 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
6870 false, false, complain);
6871 if (sub == error_mark_node)
6873 if (!BRACE_ENCLOSED_INITIALIZER_P (val)
6874 && !check_narrowing (TREE_TYPE (sub), val, complain))
6875 return error_mark_node;
6876 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
6877 if (!TREE_CONSTANT (sub))
6878 TREE_CONSTANT (new_ctor) = false;
6880 /* Build up the array. */
6881 elttype = cp_build_qualified_type
6882 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
6883 array = build_array_of_n_type (elttype, len);
6884 array = finish_compound_literal (array, new_ctor, complain, fcl_c99);
6885 /* Take the address explicitly rather than via decay_conversion
6886 to avoid the error about taking the address of a temporary. */
6887 array = cp_build_addr_expr (array, complain);
6888 array = cp_convert (build_pointer_type (elttype), array, complain);
6889 if (array == error_mark_node)
6890 return error_mark_node;
6892 /* Build up the initializer_list object. Note: fail gracefully
6893 if the object cannot be completed because, for example, no
6894 definition is provided (c++/80956). */
6895 totype = complete_type_or_maybe_complain (totype, NULL_TREE, complain);
6897 return error_mark_node;
6898 field = next_initializable_field (TYPE_FIELDS (totype));
6899 CONSTRUCTOR_APPEND_ELT (vec, field, array);
6900 field = next_initializable_field (DECL_CHAIN (field));
6901 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
6902 new_ctor = build_constructor (totype, vec);
6903 return get_target_expr_sfinae (new_ctor, complain);
6907 if (TREE_CODE (totype) == COMPLEX_TYPE)
6909 tree real = CONSTRUCTOR_ELT (expr, 0)->value;
6910 tree imag = CONSTRUCTOR_ELT (expr, 1)->value;
6911 real = perform_implicit_conversion (TREE_TYPE (totype),
6913 imag = perform_implicit_conversion (TREE_TYPE (totype),
6915 expr = build2 (COMPLEX_EXPR, totype, real, imag);
6918 expr = reshape_init (totype, expr, complain);
6919 expr = get_target_expr_sfinae (digest_init (totype, expr, complain),
6921 if (expr != error_mark_node)
6922 TARGET_EXPR_LIST_INIT_P (expr) = true;
6929 expr = convert_like_real (next_conversion (convs), expr, fn, argnum,
6930 convs->kind == ck_ref_bind
6931 ? issue_conversion_warnings : false,
6932 c_cast_p, complain);
6933 if (expr == error_mark_node)
6934 return error_mark_node;
6936 switch (convs->kind)
6939 expr = decay_conversion (expr, complain);
6940 if (expr == error_mark_node)
6942 if (complain & tf_error)
6944 maybe_print_user_conv_context (convs);
6946 inform (DECL_SOURCE_LOCATION (fn),
6947 " initializing argument %P of %qD", argnum, fn);
6949 return error_mark_node;
6952 if (! MAYBE_CLASS_TYPE_P (totype))
6955 /* Don't introduce copies when passing arguments along to the inherited
6957 if (current_function_decl
6958 && flag_new_inheriting_ctors
6959 && DECL_INHERITED_CTOR (current_function_decl))
6962 if (TREE_CODE (expr) == TARGET_EXPR
6963 && TARGET_EXPR_LIST_INIT_P (expr))
6964 /* Copy-list-initialization doesn't actually involve a copy. */
6969 if (convs->kind == ck_base && !convs->need_temporary_p)
6971 /* We are going to bind a reference directly to a base-class
6972 subobject of EXPR. */
6973 /* Build an expression for `*((base*) &expr)'. */
6974 expr = convert_to_base (expr, totype,
6975 !c_cast_p, /*nonnull=*/true, complain);
6979 /* Copy-initialization where the cv-unqualified version of the source
6980 type is the same class as, or a derived class of, the class of the
6981 destination [is treated as direct-initialization]. [dcl.init] */
6982 flags = LOOKUP_NORMAL;
6983 if (convs->user_conv_p)
6984 /* This conversion is being done in the context of a user-defined
6985 conversion (i.e. the second step of copy-initialization), so
6986 don't allow any more. */
6987 flags |= LOOKUP_NO_CONVERSION;
6989 flags |= LOOKUP_ONLYCONVERTING;
6990 if (convs->rvaluedness_matches_p)
6991 /* standard_conversion got LOOKUP_PREFER_RVALUE. */
6992 flags |= LOOKUP_PREFER_RVALUE;
6993 expr = build_temp (expr, totype, flags, &diag_kind, complain);
6994 if (diag_kind && complain)
6996 maybe_print_user_conv_context (convs);
6998 inform (DECL_SOURCE_LOCATION (fn),
6999 " initializing argument %P of %qD", argnum, fn);
7002 return build_cplus_new (totype, expr, complain);
7006 tree ref_type = totype;
7008 if (convs->bad_p && !next_conversion (convs)->bad_p)
7010 tree extype = TREE_TYPE (expr);
7011 if (TYPE_REF_IS_RVALUE (ref_type)
7013 error_at (loc, "cannot bind rvalue reference of type %qH to "
7014 "lvalue of type %qI", totype, extype);
7015 else if (!TYPE_REF_IS_RVALUE (ref_type) && !lvalue_p (expr)
7016 && !CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
7017 error_at (loc, "cannot bind non-const lvalue reference of "
7018 "type %qH to an rvalue of type %qI", totype, extype);
7019 else if (!reference_compatible_p (TREE_TYPE (totype), extype))
7020 error_at (loc, "binding reference of type %qH to %qI "
7021 "discards qualifiers", totype, extype);
7024 maybe_print_user_conv_context (convs);
7026 inform (DECL_SOURCE_LOCATION (fn),
7027 " initializing argument %P of %qD", argnum, fn);
7028 return error_mark_node;
7031 /* If necessary, create a temporary.
7033 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
7034 that need temporaries, even when their types are reference
7035 compatible with the type of reference being bound, so the
7036 upcoming call to cp_build_addr_expr doesn't fail. */
7037 if (convs->need_temporary_p
7038 || TREE_CODE (expr) == CONSTRUCTOR
7039 || TREE_CODE (expr) == VA_ARG_EXPR)
7041 /* Otherwise, a temporary of type "cv1 T1" is created and
7042 initialized from the initializer expression using the rules
7043 for a non-reference copy-initialization (8.5). */
7045 tree type = TREE_TYPE (ref_type);
7046 cp_lvalue_kind lvalue = lvalue_kind (expr);
7048 gcc_assert (same_type_ignoring_top_level_qualifiers_p
7049 (type, next_conversion (convs)->type));
7050 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
7051 && !TYPE_REF_IS_RVALUE (ref_type))
7053 /* If the reference is volatile or non-const, we
7054 cannot create a temporary. */
7055 if (lvalue & clk_bitfield)
7056 error_at (loc, "cannot bind bitfield %qE to %qT",
7058 else if (lvalue & clk_packed)
7059 error_at (loc, "cannot bind packed field %qE to %qT",
7062 error_at (loc, "cannot bind rvalue %qE to %qT",
7064 return error_mark_node;
7066 /* If the source is a packed field, and we must use a copy
7067 constructor, then building the target expr will require
7068 binding the field to the reference parameter to the
7069 copy constructor, and we'll end up with an infinite
7070 loop. If we can use a bitwise copy, then we'll be
7072 if ((lvalue & clk_packed)
7073 && CLASS_TYPE_P (type)
7074 && type_has_nontrivial_copy_init (type))
7076 error_at (loc, "cannot bind packed field %qE to %qT",
7078 return error_mark_node;
7080 if (lvalue & clk_bitfield)
7082 expr = convert_bitfield_to_declared_type (expr);
7083 expr = fold_convert (type, expr);
7085 expr = build_target_expr_with_type (expr, type, complain);
7088 /* Take the address of the thing to which we will bind the
7090 expr = cp_build_addr_expr (expr, complain);
7091 if (expr == error_mark_node)
7092 return error_mark_node;
7094 /* Convert it to a pointer to the type referred to by the
7095 reference. This will adjust the pointer if a derived to
7096 base conversion is being performed. */
7097 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
7099 /* Convert the pointer to the desired reference type. */
7100 return build_nop (ref_type, expr);
7104 return decay_conversion (expr, complain);
7107 /* ??? Should the address of a transaction-safe pointer point to the TM
7108 clone, and this conversion look up the primary function? */
7109 return build_nop (totype, expr);
7112 /* Warn about deprecated conversion if appropriate. */
7113 string_conv_p (totype, expr, 1);
7118 expr = convert_to_base (expr, totype, !c_cast_p,
7119 /*nonnull=*/false, complain);
7120 return build_nop (totype, expr);
7123 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
7124 c_cast_p, complain);
7130 if (convs->check_narrowing
7131 && !check_narrowing (totype, expr, complain))
7132 return error_mark_node;
7134 if (issue_conversion_warnings)
7135 expr = cp_convert_and_check (totype, expr, complain);
7137 expr = cp_convert (totype, expr, complain);
7142 /* ARG is being passed to a varargs function. Perform any conversions
7143 required. Return the converted value. */
7146 convert_arg_to_ellipsis (tree arg, tsubst_flags_t complain)
7149 location_t loc = EXPR_LOC_OR_LOC (arg, input_location);
7153 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
7154 standard conversions are performed. */
7155 arg = decay_conversion (arg, complain);
7156 arg_type = TREE_TYPE (arg);
7159 If the argument has integral or enumeration type that is subject
7160 to the integral promotions (_conv.prom_), or a floating point
7161 type that is subject to the floating point promotion
7162 (_conv.fpprom_), the value of the argument is converted to the
7163 promoted type before the call. */
7164 if (TREE_CODE (arg_type) == REAL_TYPE
7165 && (TYPE_PRECISION (arg_type)
7166 < TYPE_PRECISION (double_type_node))
7167 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
7169 if ((complain & tf_warning)
7170 && warn_double_promotion && !c_inhibit_evaluation_warnings)
7171 warning_at (loc, OPT_Wdouble_promotion,
7172 "implicit conversion from %qH to %qI when passing "
7173 "argument to function",
7174 arg_type, double_type_node);
7175 arg = convert_to_real_nofold (double_type_node, arg);
7177 else if (NULLPTR_TYPE_P (arg_type))
7178 arg = null_pointer_node;
7179 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
7181 if (SCOPED_ENUM_P (arg_type))
7183 tree prom = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg,
7185 prom = cp_perform_integral_promotions (prom, complain);
7186 if (abi_version_crosses (6)
7187 && TYPE_MODE (TREE_TYPE (prom)) != TYPE_MODE (arg_type)
7188 && (complain & tf_warning))
7189 warning_at (loc, OPT_Wabi, "scoped enum %qT passed through ... as "
7190 "%qT before -fabi-version=6, %qT after", arg_type,
7191 TREE_TYPE (prom), ENUM_UNDERLYING_TYPE (arg_type));
7192 if (!abi_version_at_least (6))
7196 arg = cp_perform_integral_promotions (arg, complain);
7199 arg = require_complete_type_sfinae (arg, complain);
7200 arg_type = TREE_TYPE (arg);
7202 if (arg != error_mark_node
7203 /* In a template (or ill-formed code), we can have an incomplete type
7204 even after require_complete_type_sfinae, in which case we don't know
7205 whether it has trivial copy or not. */
7206 && COMPLETE_TYPE_P (arg_type)
7207 && !cp_unevaluated_operand)
7209 /* [expr.call] 5.2.2/7:
7210 Passing a potentially-evaluated argument of class type (Clause 9)
7211 with a non-trivial copy constructor or a non-trivial destructor
7212 with no corresponding parameter is conditionally-supported, with
7213 implementation-defined semantics.
7215 We support it as pass-by-invisible-reference, just like a normal
7218 If the call appears in the context of a sizeof expression,
7219 it is not potentially-evaluated. */
7220 if (type_has_nontrivial_copy_init (arg_type)
7221 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type))
7223 arg = force_rvalue (arg, complain);
7224 if (complain & tf_warning)
7225 warning (OPT_Wconditionally_supported,
7226 "passing objects of non-trivially-copyable "
7227 "type %q#T through %<...%> is conditionally supported",
7229 return build1 (ADDR_EXPR, build_reference_type (arg_type), arg);
7231 /* Build up a real lvalue-to-rvalue conversion in case the
7232 copy constructor is trivial but not callable. */
7233 else if (CLASS_TYPE_P (arg_type))
7234 force_rvalue (arg, complain);
7241 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
7244 build_x_va_arg (source_location loc, tree expr, tree type)
7246 if (processing_template_decl)
7248 tree r = build_min (VA_ARG_EXPR, type, expr);
7249 SET_EXPR_LOCATION (r, loc);
7253 type = complete_type_or_else (type, NULL_TREE);
7255 if (expr == error_mark_node || !type)
7256 return error_mark_node;
7258 expr = mark_lvalue_use (expr);
7260 if (TREE_CODE (type) == REFERENCE_TYPE)
7262 error ("cannot receive reference type %qT through %<...%>", type);
7263 return error_mark_node;
7266 if (type_has_nontrivial_copy_init (type)
7267 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
7269 /* conditionally-supported behavior [expr.call] 5.2.2/7. Let's treat
7270 it as pass by invisible reference. */
7271 warning_at (loc, OPT_Wconditionally_supported,
7272 "receiving objects of non-trivially-copyable type %q#T "
7273 "through %<...%> is conditionally-supported", type);
7275 tree ref = cp_build_reference_type (type, false);
7276 expr = build_va_arg (loc, expr, ref);
7277 return convert_from_reference (expr);
7280 tree ret = build_va_arg (loc, expr, type);
7281 if (CLASS_TYPE_P (type))
7282 /* Wrap the VA_ARG_EXPR in a TARGET_EXPR now so other code doesn't need to
7283 know how to handle it. */
7284 ret = get_target_expr (ret);
7288 /* TYPE has been given to va_arg. Apply the default conversions which
7289 would have happened when passed via ellipsis. Return the promoted
7290 type, or the passed type if there is no change. */
7293 cxx_type_promotes_to (tree type)
7297 /* Perform the array-to-pointer and function-to-pointer
7299 type = type_decays_to (type);
7301 promote = type_promotes_to (type);
7302 if (same_type_p (type, promote))
7308 /* ARG is a default argument expression being passed to a parameter of
7309 the indicated TYPE, which is a parameter to FN. PARMNUM is the
7310 zero-based argument number. Do any required conversions. Return
7311 the converted value. */
7313 static GTY(()) vec<tree, va_gc> *default_arg_context;
7315 push_defarg_context (tree fn)
7316 { vec_safe_push (default_arg_context, fn); }
7319 pop_defarg_context (void)
7320 { default_arg_context->pop (); }
7323 convert_default_arg (tree type, tree arg, tree fn, int parmnum,
7324 tsubst_flags_t complain)
7329 /* See through clones. */
7330 fn = DECL_ORIGIN (fn);
7331 /* And inheriting ctors. */
7332 if (flag_new_inheriting_ctors)
7333 fn = strip_inheriting_ctors (fn);
7335 /* Detect recursion. */
7336 FOR_EACH_VEC_SAFE_ELT (default_arg_context, i, t)
7339 if (complain & tf_error)
7340 error ("recursive evaluation of default argument for %q#D", fn);
7341 return error_mark_node;
7344 /* If the ARG is an unparsed default argument expression, the
7345 conversion cannot be performed. */
7346 if (TREE_CODE (arg) == DEFAULT_ARG)
7348 if (complain & tf_error)
7349 error ("call to %qD uses the default argument for parameter %P, which "
7350 "is not yet defined", fn, parmnum);
7351 return error_mark_node;
7354 push_defarg_context (fn);
7356 if (fn && DECL_TEMPLATE_INFO (fn))
7357 arg = tsubst_default_argument (fn, parmnum, type, arg, complain);
7363 The names in the expression are bound, and the semantic
7364 constraints are checked, at the point where the default
7365 expressions appears.
7367 we must not perform access checks here. */
7368 push_deferring_access_checks (dk_no_check);
7369 /* We must make a copy of ARG, in case subsequent processing
7370 alters any part of it. */
7371 arg = break_out_target_exprs (arg, /*clear location*/true);
7373 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
7374 ICR_DEFAULT_ARGUMENT, fn, parmnum,
7376 arg = convert_for_arg_passing (type, arg, complain);
7377 pop_deferring_access_checks();
7379 pop_defarg_context ();
7384 /* Returns the type which will really be used for passing an argument of
7388 type_passed_as (tree type)
7390 /* Pass classes with copy ctors by invisible reference. */
7391 if (TREE_ADDRESSABLE (type))
7393 type = build_reference_type (type);
7394 /* There are no other pointers to this temporary. */
7395 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
7397 else if (targetm.calls.promote_prototypes (NULL_TREE)
7398 && INTEGRAL_TYPE_P (type)
7399 && COMPLETE_TYPE_P (type)
7400 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
7401 type = integer_type_node;
7406 /* Actually perform the appropriate conversion. */
7409 convert_for_arg_passing (tree type, tree val, tsubst_flags_t complain)
7413 /* If VAL is a bitfield, then -- since it has already been converted
7414 to TYPE -- it cannot have a precision greater than TYPE.
7416 If it has a smaller precision, we must widen it here. For
7417 example, passing "int f:3;" to a function expecting an "int" will
7418 not result in any conversion before this point.
7420 If the precision is the same we must not risk widening. For
7421 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
7422 often have type "int", even though the C++ type for the field is
7423 "long long". If the value is being passed to a function
7424 expecting an "int", then no conversions will be required. But,
7425 if we call convert_bitfield_to_declared_type, the bitfield will
7426 be converted to "long long". */
7427 bitfield_type = is_bitfield_expr_with_lowered_type (val);
7429 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
7430 val = convert_to_integer_nofold (TYPE_MAIN_VARIANT (bitfield_type), val);
7432 if (val == error_mark_node)
7434 /* Pass classes with copy ctors by invisible reference. */
7435 else if (TREE_ADDRESSABLE (type))
7436 val = build1 (ADDR_EXPR, build_reference_type (type), val);
7437 else if (targetm.calls.promote_prototypes (NULL_TREE)
7438 && INTEGRAL_TYPE_P (type)
7439 && COMPLETE_TYPE_P (type)
7440 && tree_int_cst_lt (TYPE_SIZE (type), TYPE_SIZE (integer_type_node)))
7441 val = cp_perform_integral_promotions (val, complain);
7442 if (complain & tf_warning)
7444 if (warn_suggest_attribute_format)
7446 tree rhstype = TREE_TYPE (val);
7447 const enum tree_code coder = TREE_CODE (rhstype);
7448 const enum tree_code codel = TREE_CODE (type);
7449 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
7451 && check_missing_format_attribute (type, rhstype))
7452 warning (OPT_Wsuggest_attribute_format,
7453 "argument of function call might be a candidate "
7454 "for a format attribute");
7456 maybe_warn_parm_abi (type, EXPR_LOC_OR_LOC (val, input_location));
7461 /* Returns non-zero iff FN is a function with magic varargs, i.e. ones for
7462 which just decay_conversion or no conversions at all should be done.
7463 This is true for some builtins which don't act like normal functions.
7464 Return 2 if no conversions at all should be done, 1 if just
7465 decay_conversion. Return 3 for special treatment of the 3rd argument
7466 for __builtin_*_overflow_p. */
7469 magic_varargs_p (tree fn)
7471 if (DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
7472 switch (DECL_FUNCTION_CODE (fn))
7474 case BUILT_IN_CLASSIFY_TYPE:
7475 case BUILT_IN_CONSTANT_P:
7476 case BUILT_IN_NEXT_ARG:
7477 case BUILT_IN_VA_START:
7480 case BUILT_IN_ADD_OVERFLOW_P:
7481 case BUILT_IN_SUB_OVERFLOW_P:
7482 case BUILT_IN_MUL_OVERFLOW_P:
7486 return lookup_attribute ("type generic",
7487 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
7493 /* Returns the decl of the dispatcher function if FN is a function version. */
7496 get_function_version_dispatcher (tree fn)
7498 tree dispatcher_decl = NULL;
7500 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
7501 && DECL_FUNCTION_VERSIONED (fn));
7503 gcc_assert (targetm.get_function_versions_dispatcher);
7504 dispatcher_decl = targetm.get_function_versions_dispatcher (fn);
7506 if (dispatcher_decl == NULL)
7508 error_at (input_location, "use of multiversioned function "
7509 "without a default");
7513 retrofit_lang_decl (dispatcher_decl);
7514 gcc_assert (dispatcher_decl != NULL);
7515 return dispatcher_decl;
7518 /* fn is a function version dispatcher that is marked used. Mark all the
7519 semantically identical function versions it will dispatch as used. */
7522 mark_versions_used (tree fn)
7524 struct cgraph_node *node;
7525 struct cgraph_function_version_info *node_v;
7526 struct cgraph_function_version_info *it_v;
7528 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
7530 node = cgraph_node::get (fn);
7534 gcc_assert (node->dispatcher_function);
7536 node_v = node->function_version ();
7540 /* All semantically identical versions are chained. Traverse and mark each
7541 one of them as used. */
7542 it_v = node_v->next;
7543 while (it_v != NULL)
7545 mark_used (it_v->this_node->decl);
7550 /* Build a call to "the copy constructor" for the type of A, even if it
7551 wouldn't be selected by normal overload resolution. Used for
7555 call_copy_ctor (tree a, tsubst_flags_t complain)
7557 tree ctype = TYPE_MAIN_VARIANT (TREE_TYPE (a));
7558 tree binfo = TYPE_BINFO (ctype);
7559 tree copy = get_copy_ctor (ctype, complain);
7560 copy = build_baselink (binfo, binfo, copy, NULL_TREE);
7561 tree ob = build_dummy_object (ctype);
7562 vec<tree, va_gc>* args = make_tree_vector_single (a);
7563 tree r = build_new_method_call (ob, copy, &args, NULL_TREE,
7564 LOOKUP_NORMAL, NULL, complain);
7565 release_tree_vector (args);
7569 /* Return true iff T refers to a base field. */
7572 is_base_field_ref (tree t)
7575 if (TREE_CODE (t) == ADDR_EXPR)
7576 t = TREE_OPERAND (t, 0);
7577 if (TREE_CODE (t) == COMPONENT_REF)
7578 t = TREE_OPERAND (t, 1);
7579 if (TREE_CODE (t) == FIELD_DECL)
7580 return DECL_FIELD_IS_BASE (t);
7584 /* We can't elide a copy from a function returning by value to a base
7585 subobject, as the callee might clobber tail padding. Return true iff this
7586 could be that case. */
7589 unsafe_copy_elision_p (tree target, tree exp)
7591 /* Copy elision only happens with a TARGET_EXPR. */
7592 if (TREE_CODE (exp) != TARGET_EXPR)
7594 tree type = TYPE_MAIN_VARIANT (TREE_TYPE (exp));
7595 /* It's safe to elide the copy for a class with no tail padding. */
7596 if (tree_int_cst_equal (TYPE_SIZE (type), CLASSTYPE_SIZE (type)))
7598 /* It's safe to elide the copy if we aren't initializing a base object. */
7599 if (!is_base_field_ref (target))
7601 tree init = TARGET_EXPR_INITIAL (exp);
7602 /* build_compound_expr pushes COMPOUND_EXPR inside TARGET_EXPR. */
7603 while (TREE_CODE (init) == COMPOUND_EXPR)
7604 init = TREE_OPERAND (init, 1);
7605 if (TREE_CODE (init) == COND_EXPR)
7607 /* We'll end up copying from each of the arms of the COND_EXPR directly
7608 into the target, so look at them. */
7609 if (tree op = TREE_OPERAND (init, 1))
7610 if (unsafe_copy_elision_p (target, op))
7612 return unsafe_copy_elision_p (target, TREE_OPERAND (init, 2));
7614 return (TREE_CODE (init) == AGGR_INIT_EXPR
7615 && !AGGR_INIT_VIA_CTOR_P (init));
7618 /* True iff C is a conversion that binds a reference to a prvalue. */
7621 conv_binds_ref_to_prvalue (conversion *c)
7623 if (c->kind != ck_ref_bind)
7625 if (c->need_temporary_p)
7628 c = next_conversion (c);
7630 if (c->kind == ck_rvalue)
7632 if (c->kind == ck_user && TREE_CODE (c->type) != REFERENCE_TYPE)
7634 if (c->kind == ck_identity && c->u.expr
7635 && TREE_CODE (c->u.expr) == TARGET_EXPR)
7641 /* Subroutine of the various build_*_call functions. Overload resolution
7642 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
7643 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
7644 bitmask of various LOOKUP_* flags which apply to the call itself. */
7647 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
7650 const vec<tree, va_gc> *args = cand->args;
7651 tree first_arg = cand->first_arg;
7652 conversion **convs = cand->convs;
7654 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
7659 unsigned int arg_index = 0;
7663 bool already_used = false;
7665 /* In a template, there is no need to perform all of the work that
7666 is normally done. We are only interested in the type of the call
7667 expression, i.e., the return type of the function. Any semantic
7668 errors will be deferred until the template is instantiated. */
7669 if (processing_template_decl)
7673 const tree *argarray;
7676 if (undeduced_auto_decl (fn))
7677 mark_used (fn, complain);
7679 /* Otherwise set TREE_USED for the benefit of -Wunused-function.
7683 return_type = TREE_TYPE (TREE_TYPE (fn));
7684 nargs = vec_safe_length (args);
7685 if (first_arg == NULL_TREE)
7686 argarray = args->address ();
7694 alcarray = XALLOCAVEC (tree, nargs);
7695 alcarray[0] = build_this (first_arg);
7696 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
7697 alcarray[ix + 1] = arg;
7698 argarray = alcarray;
7701 addr = build_addr_func (fn, complain);
7702 if (addr == error_mark_node)
7703 return error_mark_node;
7704 expr = build_call_array_loc (input_location, return_type,
7705 addr, nargs, argarray);
7706 if (TREE_THIS_VOLATILE (fn) && cfun)
7707 current_function_returns_abnormally = 1;
7708 return convert_from_reference (expr);
7711 /* Give any warnings we noticed during overload resolution. */
7712 if (cand->warnings && (complain & tf_warning))
7714 struct candidate_warning *w;
7715 for (w = cand->warnings; w; w = w->next)
7716 joust (cand, w->loser, 1, complain);
7719 /* Core issue 2327: P0135 doesn't say how to handle the case where the
7720 argument to the copy constructor ends up being a prvalue after
7721 conversion. Let's do the normal processing, but pretend we aren't
7722 actually using the copy constructor. */
7723 bool force_elide = false;
7724 if (cxx_dialect >= cxx17
7725 && cand->num_convs == 1
7726 && DECL_COMPLETE_CONSTRUCTOR_P (fn)
7727 && (DECL_COPY_CONSTRUCTOR_P (fn)
7728 || DECL_MOVE_CONSTRUCTOR_P (fn))
7729 && conv_binds_ref_to_prvalue (convs[0]))
7732 goto not_really_used;
7735 /* OK, we're actually calling this inherited constructor; set its deletedness
7736 appropriately. We can get away with doing this here because calling is
7737 the only way to refer to a constructor. */
7738 if (DECL_INHERITED_CTOR (fn))
7739 deduce_inheriting_ctor (fn);
7741 /* Make =delete work with SFINAE. */
7742 if (DECL_DELETED_FN (fn))
7744 if (complain & tf_error)
7746 return error_mark_node;
7749 if (DECL_FUNCTION_MEMBER_P (fn))
7752 /* If FN is a template function, two cases must be considered.
7757 template <class T> void f();
7759 template <class T> struct B {
7763 struct C : A, B<int> {
7765 using B<int>::g; // #2
7768 In case #1 where `A::f' is a member template, DECL_ACCESS is
7769 recorded in the primary template but not in its specialization.
7770 We check access of FN using its primary template.
7772 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
7773 because it is a member of class template B, DECL_ACCESS is
7774 recorded in the specialization `B<int>::g'. We cannot use its
7775 primary template because `B<T>::g' and `B<int>::g' may have
7776 different access. */
7777 if (DECL_TEMPLATE_INFO (fn)
7778 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
7779 access_fn = DECL_TI_TEMPLATE (fn);
7782 if (!perform_or_defer_access_check (cand->access_path, access_fn,
7784 return error_mark_node;
7787 /* If we're checking for implicit delete, don't bother with argument
7789 if (flags & LOOKUP_SPECULATIVE)
7791 if (cand->viable == 1)
7793 else if (!(complain & tf_error))
7794 /* Reject bad conversions now. */
7795 return error_mark_node;
7796 /* else continue to get conversion error. */
7801 /* N3276 magic doesn't apply to nested calls. */
7802 tsubst_flags_t decltype_flag = (complain & tf_decltype);
7803 complain &= ~tf_decltype;
7804 /* No-Cleanup doesn't apply to nested calls either. */
7805 tsubst_flags_t no_cleanup_complain = complain;
7806 complain &= ~tf_no_cleanup;
7808 /* Find maximum size of vector to hold converted arguments. */
7809 parmlen = list_length (parm);
7810 nargs = vec_safe_length (args) + (first_arg != NULL_TREE ? 1 : 0);
7811 if (parmlen > nargs)
7813 argarray = XALLOCAVEC (tree, nargs);
7815 /* The implicit parameters to a constructor are not considered by overload
7816 resolution, and must be of the proper type. */
7817 if (DECL_CONSTRUCTOR_P (fn))
7820 if (first_arg != NULL_TREE)
7822 object_arg = first_arg;
7823 first_arg = NULL_TREE;
7827 object_arg = (*args)[arg_index];
7830 argarray[j++] = build_this (object_arg);
7831 parm = TREE_CHAIN (parm);
7832 /* We should never try to call the abstract constructor. */
7833 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
7835 if (DECL_HAS_VTT_PARM_P (fn))
7837 argarray[j++] = (*args)[arg_index];
7839 parm = TREE_CHAIN (parm);
7842 if (flags & LOOKUP_PREFER_RVALUE)
7844 /* The implicit move specified in 15.8.3/3 fails "...if the type of
7845 the first parameter of the selected constructor is not an rvalue
7846 reference to the object’s type (possibly cv-qualified)...." */
7847 gcc_assert (!(complain & tf_error));
7848 tree ptype = convs[0]->type;
7849 if (TREE_CODE (ptype) != REFERENCE_TYPE
7850 || !TYPE_REF_IS_RVALUE (ptype)
7851 || CONVERSION_RANK (convs[0]) > cr_exact)
7852 return error_mark_node;
7855 /* Bypass access control for 'this' parameter. */
7856 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
7858 tree parmtype = TREE_VALUE (parm);
7859 tree arg = build_this (first_arg != NULL_TREE
7861 : (*args)[arg_index]);
7862 tree argtype = TREE_TYPE (arg);
7866 if (arg == error_mark_node)
7867 return error_mark_node;
7869 if (convs[i]->bad_p)
7871 if (complain & tf_error)
7873 if (permerror (input_location, "passing %qT as %<this%> "
7874 "argument discards qualifiers",
7875 TREE_TYPE (argtype)))
7876 inform (DECL_SOURCE_LOCATION (fn), " in call to %qD", fn);
7879 return error_mark_node;
7882 /* See if the function member or the whole class type is declared
7883 final and the call can be devirtualized. */
7884 if (DECL_FINAL_P (fn)
7885 || CLASSTYPE_FINAL (TYPE_METHOD_BASETYPE (TREE_TYPE (fn))))
7886 flags |= LOOKUP_NONVIRTUAL;
7888 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
7889 X is called for an object that is not of type X, or of a type
7890 derived from X, the behavior is undefined.
7892 So we can assume that anything passed as 'this' is non-null, and
7893 optimize accordingly. */
7894 gcc_assert (TYPE_PTR_P (parmtype));
7895 /* Convert to the base in which the function was declared. */
7896 gcc_assert (cand->conversion_path != NULL_TREE);
7897 converted_arg = build_base_path (PLUS_EXPR,
7899 cand->conversion_path,
7901 /* Check that the base class is accessible. */
7902 if (!accessible_base_p (TREE_TYPE (argtype),
7903 BINFO_TYPE (cand->conversion_path), true))
7905 if (complain & tf_error)
7906 error ("%qT is not an accessible base of %qT",
7907 BINFO_TYPE (cand->conversion_path),
7908 TREE_TYPE (argtype));
7910 return error_mark_node;
7912 /* If fn was found by a using declaration, the conversion path
7913 will be to the derived class, not the base declaring fn. We
7914 must convert from derived to base. */
7915 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
7916 TREE_TYPE (parmtype), ba_unique,
7918 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
7919 base_binfo, 1, complain);
7921 argarray[j++] = converted_arg;
7922 parm = TREE_CHAIN (parm);
7923 if (first_arg != NULL_TREE)
7924 first_arg = NULL_TREE;
7931 gcc_assert (first_arg == NULL_TREE);
7932 for (; arg_index < vec_safe_length (args) && parm;
7933 parm = TREE_CHAIN (parm), ++arg_index, ++i)
7935 tree type = TREE_VALUE (parm);
7936 tree arg = (*args)[arg_index];
7937 bool conversion_warning = true;
7941 /* If the argument is NULL and used to (implicitly) instantiate a
7942 template function (and bind one of the template arguments to
7943 the type of 'long int'), we don't want to warn about passing NULL
7944 to non-pointer argument.
7945 For example, if we have this template function:
7947 template<typename T> void func(T x) {}
7949 we want to warn (when -Wconversion is enabled) in this case:
7955 but not in this case:
7961 if (null_node_p (arg)
7962 && DECL_TEMPLATE_INFO (fn)
7963 && cand->template_decl
7964 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS))
7965 conversion_warning = false;
7967 /* Warn about initializer_list deduction that isn't currently in the
7969 if (cxx_dialect > cxx98
7970 && flag_deduce_init_list
7971 && cand->template_decl
7972 && is_std_init_list (non_reference (type))
7973 && BRACE_ENCLOSED_INITIALIZER_P (arg))
7975 tree tmpl = TI_TEMPLATE (cand->template_decl);
7976 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
7977 tree patparm = get_pattern_parm (realparm, tmpl);
7978 tree pattype = TREE_TYPE (patparm);
7979 if (PACK_EXPANSION_P (pattype))
7980 pattype = PACK_EXPANSION_PATTERN (pattype);
7981 pattype = non_reference (pattype);
7983 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
7984 && (cand->explicit_targs == NULL_TREE
7985 || (TREE_VEC_LENGTH (cand->explicit_targs)
7986 <= TEMPLATE_TYPE_IDX (pattype))))
7988 pedwarn (input_location, 0, "deducing %qT as %qT",
7989 non_reference (TREE_TYPE (patparm)),
7990 non_reference (type));
7991 pedwarn (DECL_SOURCE_LOCATION (cand->fn), 0,
7992 " in call to %qD", cand->fn);
7993 pedwarn (input_location, 0,
7994 " (you can disable this with -fno-deduce-init-list)");
7998 /* Set user_conv_p on the argument conversions, so rvalue/base handling
7999 knows not to allow any more UDCs. This needs to happen after we
8000 process cand->warnings. */
8001 if (flags & LOOKUP_NO_CONVERSION)
8002 conv->user_conv_p = true;
8004 tsubst_flags_t arg_complain = complain;
8005 if (!conversion_warning)
8006 arg_complain &= ~tf_warning;
8008 val = convert_like_with_context (conv, arg, fn, i - is_method,
8010 val = convert_for_arg_passing (type, val, arg_complain);
8012 if (val == error_mark_node)
8013 return error_mark_node;
8015 argarray[j++] = val;
8018 /* Default arguments */
8019 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
8021 if (TREE_VALUE (parm) == error_mark_node)
8022 return error_mark_node;
8023 val = convert_default_arg (TREE_VALUE (parm),
8024 TREE_PURPOSE (parm),
8027 if (val == error_mark_node)
8028 return error_mark_node;
8029 argarray[j++] = val;
8033 int magic = magic_varargs_p (fn);
8034 for (; arg_index < vec_safe_length (args); ++arg_index)
8036 tree a = (*args)[arg_index];
8037 if ((magic == 3 && arg_index == 2) || magic == 2)
8039 /* Do no conversions for certain magic varargs. */
8040 a = mark_type_use (a);
8041 if (TREE_CODE (a) == FUNCTION_DECL && reject_gcc_builtin (a))
8042 return error_mark_node;
8044 else if (magic != 0)
8045 /* For other magic varargs only do decay_conversion. */
8046 a = decay_conversion (a, complain);
8047 else if (DECL_CONSTRUCTOR_P (fn)
8048 && same_type_ignoring_top_level_qualifiers_p (DECL_CONTEXT (fn),
8051 /* Avoid infinite recursion trying to call A(...). */
8052 if (complain & tf_error)
8053 /* Try to call the actual copy constructor for a good error. */
8054 call_copy_ctor (a, complain);
8055 return error_mark_node;
8058 a = convert_arg_to_ellipsis (a, complain);
8059 if (a == error_mark_node)
8060 return error_mark_node;
8064 gcc_assert (j <= nargs);
8067 /* Avoid to do argument-transformation, if warnings for format, and for
8068 nonnull are disabled. Just in case that at least one of them is active
8069 the check_function_arguments function might warn about something. */
8071 bool warned_p = false;
8074 || warn_suggest_attribute_format
8077 tree *fargs = (!nargs ? argarray
8078 : (tree *) alloca (nargs * sizeof (tree)));
8079 for (j = 0; j < nargs; j++)
8081 /* For -Wformat undo the implicit passing by hidden reference
8082 done by convert_arg_to_ellipsis. */
8083 if (TREE_CODE (argarray[j]) == ADDR_EXPR
8084 && TREE_CODE (TREE_TYPE (argarray[j])) == REFERENCE_TYPE)
8085 fargs[j] = TREE_OPERAND (argarray[j], 0);
8087 fargs[j] = maybe_constant_value (argarray[j]);
8090 warned_p = check_function_arguments (input_location, fn, TREE_TYPE (fn),
8091 nargs, fargs, NULL);
8094 if (DECL_INHERITED_CTOR (fn))
8096 /* Check for passing ellipsis arguments to an inherited constructor. We
8097 could handle this by open-coding the inherited constructor rather than
8098 defining it, but let's not bother now. */
8099 if (!cp_unevaluated_operand
8101 && cand->convs[cand->num_convs-1]->ellipsis_p)
8103 if (complain & tf_error)
8105 sorry ("passing arguments to ellipsis of inherited constructor "
8107 inform (DECL_SOURCE_LOCATION (cand->fn), "declared here");
8109 return error_mark_node;
8112 /* A base constructor inheriting from a virtual base doesn't get the
8113 inherited arguments, just this and __vtt. */
8114 if (ctor_omit_inherited_parms (fn))
8118 /* Avoid actually calling copy constructors and copy assignment operators,
8121 if (! flag_elide_constructors && !force_elide)
8122 /* Do things the hard way. */;
8123 else if (cand->num_convs == 1
8124 && (DECL_COPY_CONSTRUCTOR_P (fn)
8125 || DECL_MOVE_CONSTRUCTOR_P (fn))
8126 /* It's unsafe to elide the constructor when handling
8127 a noexcept-expression, it may evaluate to the wrong
8128 value (c++/53025). */
8129 && (force_elide || cp_noexcept_operand == 0))
8132 tree arg = argarray[num_artificial_parms_for (fn)];
8134 bool trivial = trivial_fn_p (fn);
8136 /* Pull out the real argument, disregarding const-correctness. */
8138 /* Strip the reference binding for the constructor parameter. */
8139 if (CONVERT_EXPR_P (targ)
8140 && TREE_CODE (TREE_TYPE (targ)) == REFERENCE_TYPE)
8141 targ = TREE_OPERAND (targ, 0);
8142 /* But don't strip any other reference bindings; binding a temporary to a
8143 reference prevents copy elision. */
8144 while ((CONVERT_EXPR_P (targ)
8145 && TREE_CODE (TREE_TYPE (targ)) != REFERENCE_TYPE)
8146 || TREE_CODE (targ) == NON_LVALUE_EXPR)
8147 targ = TREE_OPERAND (targ, 0);
8148 if (TREE_CODE (targ) == ADDR_EXPR)
8150 targ = TREE_OPERAND (targ, 0);
8151 if (!same_type_ignoring_top_level_qualifiers_p
8152 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
8161 arg = cp_build_fold_indirect_ref (arg);
8163 /* In C++17 we shouldn't be copying a TARGET_EXPR except into a base
8165 if (CHECKING_P && cxx_dialect >= cxx17)
8166 gcc_assert (TREE_CODE (arg) != TARGET_EXPR
8168 /* It's from binding the ref parm to a packed field. */
8169 || convs[0]->need_temporary_p
8171 /* See unsafe_copy_elision_p. */
8172 || DECL_BASE_CONSTRUCTOR_P (fn));
8174 /* [class.copy]: the copy constructor is implicitly defined even if
8175 the implementation elided its use. */
8176 if (!trivial && !force_elide)
8178 if (!mark_used (fn, complain) && !(complain & tf_error))
8179 return error_mark_node;
8180 already_used = true;
8183 /* If we're creating a temp and we already have one, don't create a
8184 new one. If we're not creating a temp but we get one, use
8185 INIT_EXPR to collapse the temp into our target. Otherwise, if the
8186 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
8187 temp or an INIT_EXPR otherwise. */
8189 if (is_dummy_object (fa))
8191 if (TREE_CODE (arg) == TARGET_EXPR)
8194 return force_target_expr (DECL_CONTEXT (fn), arg, complain);
8196 else if ((trivial || TREE_CODE (arg) == TARGET_EXPR)
8197 && !unsafe_copy_elision_p (fa, arg))
8199 tree to = cp_stabilize_reference (cp_build_fold_indirect_ref (fa));
8201 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
8205 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
8206 && DECL_OVERLOADED_OPERATOR_IS (fn, NOP_EXPR)
8207 && trivial_fn_p (fn))
8209 tree to = cp_stabilize_reference
8210 (cp_build_fold_indirect_ref (argarray[0]));
8211 tree type = TREE_TYPE (to);
8212 tree as_base = CLASSTYPE_AS_BASE (type);
8213 tree arg = argarray[1];
8215 if (is_really_empty_class (type))
8217 /* Avoid copying empty classes. */
8218 val = build2 (COMPOUND_EXPR, type, arg, to);
8219 TREE_NO_WARNING (val) = 1;
8221 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
8223 arg = cp_build_fold_indirect_ref (arg);
8224 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
8228 /* We must only copy the non-tail padding parts. */
8230 tree array_type, alias_set;
8232 arg2 = TYPE_SIZE_UNIT (as_base);
8233 arg0 = cp_build_addr_expr (to, complain);
8235 array_type = build_array_type (unsigned_char_type_node,
8237 (size_binop (MINUS_EXPR,
8238 arg2, size_int (1))));
8239 alias_set = build_int_cst (build_pointer_type (type), 0);
8240 t = build2 (MODIFY_EXPR, void_type_node,
8241 build2 (MEM_REF, array_type, arg0, alias_set),
8242 build2 (MEM_REF, array_type, arg, alias_set));
8243 val = build2 (COMPOUND_EXPR, TREE_TYPE (to), t, to);
8244 TREE_NO_WARNING (val) = 1;
8249 else if (trivial_fn_p (fn))
8251 if (DECL_DESTRUCTOR_P (fn))
8252 return fold_convert (void_type_node, argarray[0]);
8253 else if (default_ctor_p (fn))
8255 if (is_dummy_object (argarray[0]))
8256 return force_target_expr (DECL_CONTEXT (fn), void_node,
8257 no_cleanup_complain);
8259 return cp_build_fold_indirect_ref (argarray[0]);
8263 gcc_assert (!force_elide);
8266 && !mark_used (fn, complain))
8267 return error_mark_node;
8269 /* Warn if the built-in writes to an object of a non-trivial type. */
8270 if (warn_class_memaccess
8271 && vec_safe_length (args) >= 2
8272 && DECL_BUILT_IN_CLASS (fn) == BUILT_IN_NORMAL)
8273 maybe_warn_class_memaccess (input_location, fn, args);
8275 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0
8276 /* Don't mess with virtual lookup in instantiate_non_dependent_expr;
8277 virtual functions can't be constexpr. */
8278 && !in_template_function ())
8281 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
8283 ba_any, NULL, complain);
8284 gcc_assert (binfo && binfo != error_mark_node);
8286 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1,
8288 if (TREE_SIDE_EFFECTS (argarray[0]))
8289 argarray[0] = save_expr (argarray[0]);
8290 t = build_pointer_type (TREE_TYPE (fn));
8291 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
8296 fn = build_addr_func (fn, complain);
8297 if (fn == error_mark_node)
8298 return error_mark_node;
8301 tree call = build_cxx_call (fn, nargs, argarray, complain|decltype_flag);
8302 if (call == error_mark_node)
8304 if (cand->flags & LOOKUP_LIST_INIT_CTOR)
8306 tree c = extract_call_expr (call);
8307 /* build_new_op_1 will clear this when appropriate. */
8308 CALL_EXPR_ORDERED_ARGS (c) = true;
8312 tree c = extract_call_expr (call);
8313 if (TREE_CODE (c) == CALL_EXPR)
8314 TREE_NO_WARNING (c) = 1;
8322 /* Return the DECL of the first non-static subobject of class TYPE
8323 that satisfies the predicate PRED or null if none can be found. */
8325 template <class Predicate>
8327 first_non_static_field (tree type, Predicate pred)
8329 if (!type || !CLASS_TYPE_P (type))
8332 for (tree field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
8334 if (TREE_CODE (field) != FIELD_DECL)
8336 if (TREE_STATIC (field))
8344 for (tree base_binfo, binfo = TYPE_BINFO (type);
8345 BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
8347 tree base = TREE_TYPE (base_binfo);
8350 if (tree field = first_non_static_field (base, pred))
8357 struct NonPublicField
8359 bool operator() (const_tree t)
8361 return DECL_P (t) && (TREE_PRIVATE (t) || TREE_PROTECTED (t));
8365 /* Return the DECL of the first non-public subobject of class TYPE
8366 or null if none can be found. */
8369 first_non_public_field (tree type)
8371 return first_non_static_field (type, NonPublicField ());
8374 struct NonTrivialField
8376 bool operator() (const_tree t)
8378 return !trivial_type_p (DECL_P (t) ? TREE_TYPE (t) : t);
8382 /* Return the DECL of the first non-trivial subobject of class TYPE
8383 or null if none can be found. */
8386 first_non_trivial_field (tree type)
8388 return first_non_static_field (type, NonTrivialField ());
8391 } /* unnamed namespace */
8393 /* Return true if all copy and move assignment operator overloads for
8394 class TYPE are trivial and at least one of them is not deleted and,
8395 when ACCESS is set, accessible. Return false otherwise. Set
8396 HASASSIGN to true when the TYPE has a (not necessarily trivial)
8397 copy or move assignment. */
8400 has_trivial_copy_assign_p (tree type, bool access, bool *hasassign)
8402 tree fns = get_class_binding (type, assign_op_identifier);
8403 bool all_trivial = true;
8405 /* Iterate over overloads of the assignment operator, checking
8406 accessible copy assignments for triviality. */
8408 for (ovl_iterator oi (fns); oi; ++oi)
8412 /* Skip operators that aren't copy assignments. */
8416 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f))
8417 || accessible_p (TYPE_BINFO (type), f, true));
8419 /* Skip template assignment operators and deleted functions. */
8420 if (TREE_CODE (f) != FUNCTION_DECL || DECL_DELETED_FN (f))
8426 if (!accessible || !trivial_fn_p (f))
8427 all_trivial = false;
8429 /* Break early when both properties have been determined. */
8430 if (*hasassign && !all_trivial)
8434 /* Return true if they're all trivial and one of the expressions
8435 TYPE() = TYPE() or TYPE() = (TYPE&)() is valid. */
8436 tree ref = cp_build_reference_type (type, false);
8438 && (is_trivially_xible (MODIFY_EXPR, type, type)
8439 || is_trivially_xible (MODIFY_EXPR, type, ref)));
8442 /* Return true if all copy and move ctor overloads for class TYPE are
8443 trivial and at least one of them is not deleted and, when ACCESS is
8444 set, accessible. Return false otherwise. Set each element of HASCTOR[]
8445 to true when the TYPE has a (not necessarily trivial) default and copy
8446 (or move) ctor, respectively. */
8449 has_trivial_copy_p (tree type, bool access, bool hasctor[2])
8451 tree fns = get_class_binding (type, complete_ctor_identifier);
8452 bool all_trivial = true;
8454 for (ovl_iterator oi (fns); oi; ++oi)
8458 /* Skip template constructors. */
8459 if (TREE_CODE (f) != FUNCTION_DECL)
8462 bool cpy_or_move_ctor_p = copy_fn_p (f);
8464 /* Skip ctors other than default, copy, and move. */
8465 if (!cpy_or_move_ctor_p && !default_ctor_p (f))
8468 if (DECL_DELETED_FN (f))
8471 bool accessible = (!access || !(TREE_PRIVATE (f) || TREE_PROTECTED (f))
8472 || accessible_p (TYPE_BINFO (type), f, true));
8475 hasctor[cpy_or_move_ctor_p] = true;
8477 if (cpy_or_move_ctor_p && (!accessible || !trivial_fn_p (f)))
8478 all_trivial = false;
8480 /* Break early when both properties have been determined. */
8481 if (hasctor[0] && hasctor[1] && !all_trivial)
8488 /* Issue a warning on a call to the built-in function FNDECL if it is
8489 a raw memory write whose destination is not an object of (something
8490 like) trivial or standard layout type with a non-deleted assignment
8491 and copy ctor. Detects const correctness violations, corrupting
8492 references, virtual table pointers, and bypassing non-trivial
8496 maybe_warn_class_memaccess (location_t loc, tree fndecl,
8497 const vec<tree, va_gc> *args)
8499 /* Except for bcopy where it's second, the destination pointer is
8500 the first argument for all functions handled here. Compute
8501 the index of the destination and source arguments. */
8502 unsigned dstidx = DECL_FUNCTION_CODE (fndecl) == BUILT_IN_BCOPY;
8503 unsigned srcidx = !dstidx;
8505 tree dest = (*args)[dstidx];
8506 if (!TREE_TYPE (dest) || !POINTER_TYPE_P (TREE_TYPE (dest)))
8509 tree srctype = NULL_TREE;
8511 /* Determine the type of the pointed-to object and whether it's
8512 a complete class type. */
8513 tree desttype = TREE_TYPE (TREE_TYPE (dest));
8515 if (!desttype || !COMPLETE_TYPE_P (desttype) || !CLASS_TYPE_P (desttype))
8518 /* Check to see if the raw memory call is made by a non-static member
8519 function with THIS as the destination argument for the destination
8520 type. If so, and if the class has no non-trivial bases or members,
8521 be more permissive. */
8522 if (current_function_decl
8523 && DECL_NONSTATIC_MEMBER_FUNCTION_P (current_function_decl)
8524 && is_this_parameter (tree_strip_nop_conversions (dest)))
8526 tree ctx = DECL_CONTEXT (current_function_decl);
8527 bool special = same_type_ignoring_top_level_qualifiers_p (ctx, desttype);
8528 tree binfo = TYPE_BINFO (ctx);
8530 /* FIXME: The following if statement is overly permissive (see
8531 bug 84851). Remove it in GCC 9. */
8533 && !BINFO_VTABLE (binfo)
8534 && !BINFO_N_BASE_BINFOS (binfo)
8535 && (DECL_CONSTRUCTOR_P (current_function_decl)
8536 || DECL_DESTRUCTOR_P (current_function_decl)))
8540 && !BINFO_VTABLE (binfo)
8541 && !first_non_trivial_field (desttype))
8545 /* True if the class is trivial. */
8546 bool trivial = trivial_type_p (desttype);
8548 /* Set to true if DESTYPE has an accessible copy assignment. */
8549 bool hasassign = false;
8550 /* True if all of the class' overloaded copy assignment operators
8551 are all trivial (and not deleted) and at least one of them is
8553 bool trivassign = has_trivial_copy_assign_p (desttype, true, &hasassign);
8555 /* Set to true if DESTTYPE has an accessible default and copy ctor,
8557 bool hasctors[2] = { false, false };
8559 /* True if all of the class' overloaded copy constructors are all
8560 trivial (and not deleted) and at least one of them is accessible. */
8561 bool trivcopy = has_trivial_copy_p (desttype, true, hasctors);
8563 /* Set FLD to the first private/protected member of the class. */
8564 tree fld = trivial ? first_non_public_field (desttype) : NULL_TREE;
8566 /* The warning format string. */
8567 const char *warnfmt = NULL;
8568 /* A suggested alternative to offer instead of the raw memory call.
8569 Empty string when none can be come up with. */
8570 const char *suggest = "";
8571 bool warned = false;
8573 switch (DECL_FUNCTION_CODE (fndecl))
8575 case BUILT_IN_MEMSET:
8576 if (!integer_zerop (maybe_constant_value ((*args)[1])))
8578 /* Diagnose setting non-copy-assignable or non-trivial types,
8579 or types with a private member, to (potentially) non-zero
8580 bytes. Since the value of the bytes being written is unknown,
8581 suggest using assignment instead (if one exists). Also warn
8582 for writes into objects for which zero-initialization doesn't
8583 mean all bits clear (pointer-to-member data, where null is all
8584 bits set). Since the value being written is (most likely)
8585 non-zero, simply suggest assignment (but not copy assignment). */
8586 suggest = "; use assignment instead";
8588 warnfmt = G_("%qD writing to an object of type %#qT with "
8589 "no trivial copy-assignment");
8591 warnfmt = G_("%qD writing to an object of non-trivial type %#qT%s");
8594 const char *access = TREE_PRIVATE (fld) ? "private" : "protected";
8595 warned = warning_at (loc, OPT_Wclass_memaccess,
8596 "%qD writing to an object of type %#qT with "
8598 fndecl, desttype, access, fld);
8600 else if (!zero_init_p (desttype))
8601 warnfmt = G_("%qD writing to an object of type %#qT containing "
8602 "a pointer to data member%s");
8608 case BUILT_IN_BZERO:
8609 /* Similarly to the above, diagnose clearing non-trivial or non-
8610 standard layout objects, or objects of types with no assignmenmt.
8611 Since the value being written is known to be zero, suggest either
8612 copy assignment, copy ctor, or default ctor as an alternative,
8613 depending on what's available. */
8615 if (hasassign && hasctors[0])
8616 suggest = G_("; use assignment or value-initialization instead");
8618 suggest = G_("; use assignment instead");
8619 else if (hasctors[0])
8620 suggest = G_("; use value-initialization instead");
8623 warnfmt = G_("%qD clearing an object of type %#qT with "
8624 "no trivial copy-assignment%s");
8626 warnfmt = G_("%qD clearing an object of non-trivial type %#qT%s");
8627 else if (!zero_init_p (desttype))
8628 warnfmt = G_("%qD clearing an object of type %#qT containing "
8629 "a pointer-to-member%s");
8632 case BUILT_IN_BCOPY:
8633 case BUILT_IN_MEMCPY:
8634 case BUILT_IN_MEMMOVE:
8635 case BUILT_IN_MEMPCPY:
8636 /* Determine the type of the source object. */
8637 srctype = TREE_TYPE ((*args)[srcidx]);
8638 if (!srctype || !POINTER_TYPE_P (srctype))
8639 srctype = void_type_node;
8641 srctype = TREE_TYPE (srctype);
8643 /* Since it's impossible to determine wheter the byte copy is
8644 being used in place of assignment to an existing object or
8645 as a substitute for initialization, assume it's the former.
8646 Determine the best alternative to use instead depending on
8647 what's not deleted. */
8648 if (hasassign && hasctors[1])
8649 suggest = G_("; use copy-assignment or copy-initialization instead");
8651 suggest = G_("; use copy-assignment instead");
8652 else if (hasctors[1])
8653 suggest = G_("; use copy-initialization instead");
8656 warnfmt = G_("%qD writing to an object of type %#qT with no trivial "
8657 "copy-assignment%s");
8658 else if (!trivially_copyable_p (desttype))
8659 warnfmt = G_("%qD writing to an object of non-trivially copyable "
8662 warnfmt = G_("%qD writing to an object with a deleted copy constructor");
8665 && !VOID_TYPE_P (srctype)
8666 && !char_type_p (TYPE_MAIN_VARIANT (srctype))
8667 && !same_type_ignoring_top_level_qualifiers_p (desttype,
8670 /* Warn when copying into a non-trivial object from an object
8671 of a different type other than void or char. */
8672 warned = warning_at (loc, OPT_Wclass_memaccess,
8673 "%qD copying an object of non-trivial type "
8674 "%#qT from an array of %#qT",
8675 fndecl, desttype, srctype);
8678 && !VOID_TYPE_P (srctype)
8679 && !char_type_p (TYPE_MAIN_VARIANT (srctype))
8680 && !same_type_ignoring_top_level_qualifiers_p (desttype,
8683 const char *access = TREE_PRIVATE (fld) ? "private" : "protected";
8684 warned = warning_at (loc, OPT_Wclass_memaccess,
8685 "%qD copying an object of type %#qT with "
8686 "%qs member %qD from an array of %#qT; use "
8687 "assignment or copy-initialization instead",
8688 fndecl, desttype, access, fld, srctype);
8690 else if (!trivial && vec_safe_length (args) > 2)
8692 tree sz = maybe_constant_value ((*args)[2]);
8693 if (!tree_fits_uhwi_p (sz))
8696 /* Finally, warn on partial copies. */
8697 unsigned HOST_WIDE_INT typesize
8698 = tree_to_uhwi (TYPE_SIZE_UNIT (desttype));
8699 if (unsigned HOST_WIDE_INT partial = tree_to_uhwi (sz) % typesize)
8700 warned = warning_at (loc, OPT_Wclass_memaccess,
8701 (typesize - partial > 1
8702 ? G_("%qD writing to an object of "
8703 "a non-trivial type %#qT leaves %wu "
8705 : G_("%qD writing to an object of "
8706 "a non-trivial type %#qT leaves %wu "
8708 fndecl, desttype, typesize - partial);
8712 case BUILT_IN_REALLOC:
8714 if (!trivially_copyable_p (desttype))
8715 warnfmt = G_("%qD moving an object of non-trivially copyable type "
8716 "%#qT; use %<new%> and %<delete%> instead");
8718 warnfmt = G_("%qD moving an object of type %#qT with deleted copy "
8719 "constructor; use %<new%> and %<delete%> instead");
8720 else if (!get_dtor (desttype, tf_none))
8721 warnfmt = G_("%qD moving an object of type %#qT with deleted "
8725 tree sz = maybe_constant_value ((*args)[1]);
8726 if (TREE_CODE (sz) == INTEGER_CST
8727 && tree_int_cst_lt (sz, TYPE_SIZE_UNIT (desttype)))
8728 /* Finally, warn on reallocation into insufficient space. */
8729 warned = warning_at (loc, OPT_Wclass_memaccess,
8730 "%qD moving an object of non-trivial type "
8731 "%#qT and size %E into a region of size %E",
8732 fndecl, desttype, TYPE_SIZE_UNIT (desttype),
8744 warned = warning_at (loc, OPT_Wclass_memaccess,
8745 warnfmt, fndecl, desttype, suggest);
8747 warned = warning_at (loc, OPT_Wclass_memaccess,
8748 warnfmt, fndecl, desttype);
8752 inform (location_of (desttype), "%#qT declared here", desttype);
8755 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
8756 This function performs no overload resolution, conversion, or other
8757 high-level operations. */
8760 build_cxx_call (tree fn, int nargs, tree *argarray,
8761 tsubst_flags_t complain)
8765 /* Remember roughly where this call is. */
8766 location_t loc = EXPR_LOC_OR_LOC (fn, input_location);
8767 fn = build_call_a (fn, nargs, argarray);
8768 SET_EXPR_LOCATION (fn, loc);
8770 fndecl = get_callee_fndecl (fn);
8772 /* Check that arguments to builtin functions match the expectations. */
8774 && DECL_BUILT_IN (fndecl)
8775 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
8779 /* We need to take care that values to BUILT_IN_NORMAL
8781 for (i = 0; i < nargs; i++)
8782 argarray[i] = fold_non_dependent_expr (argarray[i]);
8784 if (!check_builtin_function_arguments (EXPR_LOCATION (fn), vNULL, fndecl,
8786 return error_mark_node;
8789 if (VOID_TYPE_P (TREE_TYPE (fn)))
8792 /* 5.2.2/11: If a function call is a prvalue of object type: if the
8793 function call is either the operand of a decltype-specifier or the
8794 right operand of a comma operator that is the operand of a
8795 decltype-specifier, a temporary object is not introduced for the
8796 prvalue. The type of the prvalue may be incomplete. */
8797 if (!(complain & tf_decltype))
8799 fn = require_complete_type_sfinae (fn, complain);
8800 if (fn == error_mark_node)
8801 return error_mark_node;
8803 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
8805 fn = build_cplus_new (TREE_TYPE (fn), fn, complain);
8806 maybe_warn_parm_abi (TREE_TYPE (fn), loc);
8809 return convert_from_reference (fn);
8812 /* Returns the value to use for the in-charge parameter when making a
8813 call to a function with the indicated NAME.
8815 FIXME:Can't we find a neater way to do this mapping? */
8818 in_charge_arg_for_name (tree name)
8820 if (IDENTIFIER_CTOR_P (name))
8822 if (name == complete_ctor_identifier)
8823 return integer_one_node;
8824 gcc_checking_assert (name == base_ctor_identifier);
8828 if (name == complete_dtor_identifier)
8829 return integer_two_node;
8830 else if (name == deleting_dtor_identifier)
8831 return integer_three_node;
8832 gcc_checking_assert (name == base_dtor_identifier);
8835 return integer_zero_node;
8838 /* We've built up a constructor call RET. Complain if it delegates to the
8839 constructor we're currently compiling. */
8842 check_self_delegation (tree ret)
8844 if (TREE_CODE (ret) == TARGET_EXPR)
8845 ret = TARGET_EXPR_INITIAL (ret);
8846 tree fn = cp_get_callee_fndecl_nofold (ret);
8847 if (fn && DECL_ABSTRACT_ORIGIN (fn) == current_function_decl)
8848 error ("constructor delegates to itself");
8851 /* Build a call to a constructor, destructor, or an assignment
8852 operator for INSTANCE, an expression with class type. NAME
8853 indicates the special member function to call; *ARGS are the
8854 arguments. ARGS may be NULL. This may change ARGS. BINFO
8855 indicates the base of INSTANCE that is to be passed as the `this'
8856 parameter to the member function called.
8858 FLAGS are the LOOKUP_* flags to use when processing the call.
8860 If NAME indicates a complete object constructor, INSTANCE may be
8861 NULL_TREE. In this case, the caller will call build_cplus_new to
8862 store the newly constructed object into a VAR_DECL. */
8865 build_special_member_call (tree instance, tree name, vec<tree, va_gc> **args,
8866 tree binfo, int flags, tsubst_flags_t complain)
8869 /* The type of the subobject to be constructed or destroyed. */
8871 vec<tree, va_gc> *allocated = NULL;
8874 gcc_assert (IDENTIFIER_CDTOR_P (name) || name == assign_op_identifier);
8877 /* Resolve the name. */
8878 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
8879 return error_mark_node;
8881 binfo = TYPE_BINFO (binfo);
8884 gcc_assert (binfo != NULL_TREE);
8886 class_type = BINFO_TYPE (binfo);
8888 /* Handle the special case where INSTANCE is NULL_TREE. */
8889 if (name == complete_ctor_identifier && !instance)
8890 instance = build_dummy_object (class_type);
8893 if (IDENTIFIER_DTOR_P (name))
8894 gcc_assert (args == NULL || vec_safe_is_empty (*args));
8896 /* Convert to the base class, if necessary. */
8897 if (!same_type_ignoring_top_level_qualifiers_p
8898 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
8900 if (IDENTIFIER_CDTOR_P (name))
8901 /* For constructors and destructors, either the base is
8902 non-virtual, or it is virtual but we are doing the
8903 conversion from a constructor or destructor for the
8904 complete object. In either case, we can convert
8906 instance = convert_to_base_statically (instance, binfo);
8909 /* However, for assignment operators, we must convert
8910 dynamically if the base is virtual. */
8911 gcc_checking_assert (name == assign_op_identifier);
8912 instance = build_base_path (PLUS_EXPR, instance,
8913 binfo, /*nonnull=*/1, complain);
8918 gcc_assert (instance != NULL_TREE);
8920 /* In C++17, "If the initializer expression is a prvalue and the
8921 cv-unqualified version of the source type is the same class as the class
8922 of the destination, the initializer expression is used to initialize the
8923 destination object." Handle that here to avoid doing overload
8925 if (cxx_dialect >= cxx17
8926 && args && vec_safe_length (*args) == 1
8927 && name == complete_ctor_identifier)
8929 tree arg = (**args)[0];
8931 if (BRACE_ENCLOSED_INITIALIZER_P (arg)
8932 && !TYPE_HAS_LIST_CTOR (class_type)
8933 && CONSTRUCTOR_NELTS (arg) == 1)
8934 arg = CONSTRUCTOR_ELT (arg, 0)->value;
8936 if ((TREE_CODE (arg) == TARGET_EXPR
8937 || TREE_CODE (arg) == CONSTRUCTOR)
8938 && (same_type_ignoring_top_level_qualifiers_p
8939 (class_type, TREE_TYPE (arg))))
8941 if (is_dummy_object (instance))
8943 else if (TREE_CODE (arg) == TARGET_EXPR)
8944 TARGET_EXPR_DIRECT_INIT_P (arg) = true;
8946 if ((complain & tf_error)
8947 && (flags & LOOKUP_DELEGATING_CONS))
8948 check_self_delegation (arg);
8949 /* Avoid change of behavior on Wunused-var-2.C. */
8950 instance = mark_lvalue_use (instance);
8951 return build2 (INIT_EXPR, class_type, instance, arg);
8955 fns = lookup_fnfields (binfo, name, 1);
8957 /* When making a call to a constructor or destructor for a subobject
8958 that uses virtual base classes, pass down a pointer to a VTT for
8960 if ((name == base_ctor_identifier
8961 || name == base_dtor_identifier)
8962 && CLASSTYPE_VBASECLASSES (class_type))
8967 /* If the current function is a complete object constructor
8968 or destructor, then we fetch the VTT directly.
8969 Otherwise, we look it up using the VTT we were given. */
8970 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
8971 vtt = decay_conversion (vtt, complain);
8972 if (vtt == error_mark_node)
8973 return error_mark_node;
8974 vtt = build_if_in_charge (vtt, current_vtt_parm);
8975 if (BINFO_SUBVTT_INDEX (binfo))
8976 sub_vtt = fold_build_pointer_plus (vtt, BINFO_SUBVTT_INDEX (binfo));
8982 allocated = make_tree_vector ();
8986 vec_safe_insert (*args, 0, sub_vtt);
8989 ret = build_new_method_call (instance, fns, args,
8990 TYPE_BINFO (BINFO_TYPE (binfo)),
8994 if (allocated != NULL)
8995 release_tree_vector (allocated);
8997 if ((complain & tf_error)
8998 && (flags & LOOKUP_DELEGATING_CONS)
8999 && name == complete_ctor_identifier)
9000 check_self_delegation (ret);
9005 /* Return the NAME, as a C string. The NAME indicates a function that
9006 is a member of TYPE. *FREE_P is set to true if the caller must
9007 free the memory returned.
9009 Rather than go through all of this, we should simply set the names
9010 of constructors and destructors appropriately, and dispense with
9011 ctor_identifier, dtor_identifier, etc. */
9014 name_as_c_string (tree name, tree type, bool *free_p)
9016 const char *pretty_name;
9018 /* Assume that we will not allocate memory. */
9020 /* Constructors and destructors are special. */
9021 if (IDENTIFIER_CDTOR_P (name))
9024 = identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type)));
9025 /* For a destructor, add the '~'. */
9026 if (IDENTIFIER_DTOR_P (name))
9028 pretty_name = concat ("~", pretty_name, NULL);
9029 /* Remember that we need to free the memory allocated. */
9033 else if (IDENTIFIER_CONV_OP_P (name))
9035 pretty_name = concat ("operator ",
9036 type_as_string_translate (TREE_TYPE (name),
9037 TFF_PLAIN_IDENTIFIER),
9039 /* Remember that we need to free the memory allocated. */
9043 pretty_name = identifier_to_locale (IDENTIFIER_POINTER (name));
9045 return CONST_CAST (char *, pretty_name);
9048 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
9049 be set, upon return, to the function called. ARGS may be NULL.
9050 This may change ARGS. */
9053 build_new_method_call_1 (tree instance, tree fns, vec<tree, va_gc> **args,
9054 tree conversion_path, int flags,
9055 tree *fn_p, tsubst_flags_t complain)
9057 struct z_candidate *candidates = 0, *cand;
9058 tree explicit_targs = NULL_TREE;
9059 tree basetype = NULL_TREE;
9060 tree access_binfo, binfo;
9062 tree first_mem_arg = NULL_TREE;
9064 bool skip_first_for_error;
9065 vec<tree, va_gc> *user_args;
9068 int template_only = 0;
9072 vec<tree, va_gc> *orig_args = NULL;
9075 gcc_assert (instance != NULL_TREE);
9077 /* We don't know what function we're going to call, yet. */
9081 if (error_operand_p (instance)
9082 || !fns || error_operand_p (fns))
9083 return error_mark_node;
9085 if (!BASELINK_P (fns))
9087 if (complain & tf_error)
9088 error ("call to non-function %qD", fns);
9089 return error_mark_node;
9092 orig_instance = instance;
9095 /* Dismantle the baselink to collect all the information we need. */
9096 if (!conversion_path)
9097 conversion_path = BASELINK_BINFO (fns);
9098 access_binfo = BASELINK_ACCESS_BINFO (fns);
9099 binfo = BASELINK_BINFO (fns);
9100 optype = BASELINK_OPTYPE (fns);
9101 fns = BASELINK_FUNCTIONS (fns);
9102 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
9104 explicit_targs = TREE_OPERAND (fns, 1);
9105 fns = TREE_OPERAND (fns, 0);
9108 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
9109 || TREE_CODE (fns) == TEMPLATE_DECL
9110 || TREE_CODE (fns) == OVERLOAD);
9111 fn = OVL_FIRST (fns);
9112 name = DECL_NAME (fn);
9114 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
9115 gcc_assert (CLASS_TYPE_P (basetype));
9117 user_args = args == NULL ? NULL : *args;
9118 /* Under DR 147 A::A() is an invalid constructor call,
9119 not a functional cast. */
9120 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
9122 if (! (complain & tf_error))
9123 return error_mark_node;
9125 basetype = DECL_CONTEXT (fn);
9126 name = constructor_name (basetype);
9127 if (permerror (input_location,
9128 "cannot call constructor %<%T::%D%> directly",
9130 inform (input_location, "for a function-style cast, remove the "
9131 "redundant %<::%D%>", name);
9132 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
9137 if (processing_template_decl)
9139 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
9140 instance = build_non_dependent_expr (instance);
9142 make_args_non_dependent (*args);
9145 /* Process the argument list. */
9146 if (args != NULL && *args != NULL)
9148 *args = resolve_args (*args, complain);
9150 return error_mark_node;
9154 /* Consider the object argument to be used even if we end up selecting a
9155 static member function. */
9156 instance = mark_type_use (instance);
9158 /* Figure out whether to skip the first argument for the error
9159 message we will display to users if an error occurs. We don't
9160 want to display any compiler-generated arguments. The "this"
9161 pointer hasn't been added yet. However, we must remove the VTT
9162 pointer if this is a call to a base-class constructor or
9164 skip_first_for_error = false;
9165 if (IDENTIFIER_CDTOR_P (name))
9167 /* Callers should explicitly indicate whether they want to ctor
9168 the complete object or just the part without virtual bases. */
9169 gcc_assert (name != ctor_identifier);
9171 /* Remove the VTT pointer, if present. */
9172 if ((name == base_ctor_identifier || name == base_dtor_identifier)
9173 && CLASSTYPE_VBASECLASSES (basetype))
9174 skip_first_for_error = true;
9176 /* It's OK to call destructors and constructors on cv-qualified
9177 objects. Therefore, convert the INSTANCE to the unqualified
9178 type, if necessary. */
9179 if (!same_type_p (basetype, TREE_TYPE (instance)))
9181 instance = build_this (instance);
9182 instance = build_nop (build_pointer_type (basetype), instance);
9183 instance = build_fold_indirect_ref (instance);
9187 gcc_assert (!DECL_DESTRUCTOR_P (fn) && !DECL_CONSTRUCTOR_P (fn));
9189 /* For the overload resolution we need to find the actual `this`
9190 that would be captured if the call turns out to be to a
9191 non-static member function. Do not actually capture it at this
9193 if (DECL_CONSTRUCTOR_P (fn))
9194 /* Constructors don't use the enclosing 'this'. */
9195 first_mem_arg = instance;
9197 first_mem_arg = maybe_resolve_dummy (instance, false);
9199 /* Get the high-water mark for the CONVERSION_OBSTACK. */
9200 p = conversion_obstack_alloc (0);
9202 /* The number of arguments artificial parms in ARGS; we subtract one because
9203 there's no 'this' in ARGS. */
9204 unsigned skip = num_artificial_parms_for (fn) - 1;
9206 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
9207 initializer, not T({ }). */
9208 if (DECL_CONSTRUCTOR_P (fn)
9209 && vec_safe_length (user_args) > skip
9210 && DIRECT_LIST_INIT_P ((*user_args)[skip]))
9212 tree init_list = (*user_args)[skip];
9213 tree init = NULL_TREE;
9215 gcc_assert (user_args->length () == skip + 1
9216 && !(flags & LOOKUP_ONLYCONVERTING));
9218 /* If the initializer list has no elements and T is a class type with
9219 a default constructor, the object is value-initialized. Handle
9220 this here so we don't need to handle it wherever we use
9221 build_special_member_call. */
9222 if (CONSTRUCTOR_NELTS (init_list) == 0
9223 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
9224 /* For a user-provided default constructor, use the normal
9225 mechanisms so that protected access works. */
9226 && type_has_non_user_provided_default_constructor (basetype)
9227 && !processing_template_decl)
9228 init = build_value_init (basetype, complain);
9230 /* If BASETYPE is an aggregate, we need to do aggregate
9232 else if (CP_AGGREGATE_TYPE_P (basetype))
9234 init = reshape_init (basetype, init_list, complain);
9235 init = digest_init (basetype, init, complain);
9240 if (is_dummy_object (instance))
9241 return get_target_expr_sfinae (init, complain);
9242 init = build2 (INIT_EXPR, TREE_TYPE (instance), instance, init);
9243 TREE_SIDE_EFFECTS (init) = true;
9247 /* Otherwise go ahead with overload resolution. */
9248 add_list_candidates (fns, first_mem_arg, user_args,
9249 basetype, explicit_targs, template_only,
9250 conversion_path, access_binfo, flags,
9251 &candidates, complain);
9254 add_candidates (fns, first_mem_arg, user_args, optype,
9255 explicit_targs, template_only, conversion_path,
9256 access_binfo, flags, &candidates, complain);
9258 any_viable_p = false;
9259 candidates = splice_viable (candidates, false, &any_viable_p);
9263 if (complain & tf_error)
9265 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
9266 cxx_incomplete_type_error (instance, basetype);
9268 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
9269 basetype, optype, build_tree_list_vec (user_args),
9270 TREE_TYPE (instance));
9273 tree arglist = build_tree_list_vec (user_args);
9274 tree errname = name;
9275 bool twiddle = false;
9276 if (IDENTIFIER_CDTOR_P (errname))
9278 twiddle = IDENTIFIER_DTOR_P (errname);
9279 errname = constructor_name (basetype);
9282 errname = lookup_template_function (errname, explicit_targs);
9283 if (skip_first_for_error)
9284 arglist = TREE_CHAIN (arglist);
9285 error ("no matching function for call to %<%T::%s%E(%A)%#V%>",
9286 basetype, &"~"[!twiddle], errname, arglist,
9287 TREE_TYPE (instance));
9289 print_z_candidates (location_of (name), candidates);
9291 call = error_mark_node;
9295 cand = tourney (candidates, complain);
9302 if (complain & tf_error)
9304 pretty_name = name_as_c_string (name, basetype, &free_p);
9305 arglist = build_tree_list_vec (user_args);
9306 if (skip_first_for_error)
9307 arglist = TREE_CHAIN (arglist);
9308 if (!any_strictly_viable (candidates))
9309 error ("no matching function for call to %<%s(%A)%>",
9310 pretty_name, arglist);
9312 error ("call of overloaded %<%s(%A)%> is ambiguous",
9313 pretty_name, arglist);
9314 print_z_candidates (location_of (name), candidates);
9318 call = error_mark_node;
9325 if (!(flags & LOOKUP_NONVIRTUAL)
9326 && DECL_PURE_VIRTUAL_P (fn)
9327 && instance == current_class_ref
9328 && (complain & tf_warning))
9330 /* This is not an error, it is runtime undefined
9332 if (!current_function_decl)
9333 warning (0, "pure virtual %q#D called from "
9334 "non-static data member initializer", fn);
9335 else if (DECL_CONSTRUCTOR_P (current_function_decl)
9336 || DECL_DESTRUCTOR_P (current_function_decl))
9337 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl)
9338 ? G_("pure virtual %q#D called from constructor")
9339 : G_("pure virtual %q#D called from destructor")),
9343 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
9344 && !DECL_CONSTRUCTOR_P (fn)
9345 && is_dummy_object (instance))
9347 instance = maybe_resolve_dummy (instance, true);
9348 if (instance == error_mark_node)
9349 call = error_mark_node;
9350 else if (!is_dummy_object (instance))
9352 /* We captured 'this' in the current lambda now that
9353 we know we really need it. */
9354 cand->first_arg = instance;
9356 else if (any_dependent_bases_p ())
9357 /* We can't tell until instantiation time whether we can use
9358 *this as the implicit object argument. */;
9361 if (complain & tf_error)
9362 error ("cannot call member function %qD without object",
9364 call = error_mark_node;
9368 if (call != error_mark_node)
9370 /* Optimize away vtable lookup if we know that this
9371 function can't be overridden. We need to check if
9372 the context and the type where we found fn are the same,
9373 actually FN might be defined in a different class
9374 type because of a using-declaration. In this case, we
9375 do not want to perform a non-virtual call. */
9376 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
9377 && same_type_ignoring_top_level_qualifiers_p
9378 (DECL_CONTEXT (fn), BINFO_TYPE (binfo))
9379 && resolves_to_fixed_type_p (instance, 0))
9380 flags |= LOOKUP_NONVIRTUAL;
9382 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
9383 /* Now we know what function is being called. */
9386 /* Build the actual CALL_EXPR. */
9387 call = build_over_call (cand, flags, complain);
9388 /* In an expression of the form `a->f()' where `f' turns
9389 out to be a static member function, `a' is
9390 none-the-less evaluated. */
9391 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
9392 && !is_dummy_object (instance)
9393 && TREE_SIDE_EFFECTS (instance))
9395 /* But avoid the implicit lvalue-rvalue conversion when 'a'
9398 if (TREE_THIS_VOLATILE (a))
9400 call = build2 (COMPOUND_EXPR, TREE_TYPE (call), a, call);
9402 else if (call != error_mark_node
9403 && DECL_DESTRUCTOR_P (cand->fn)
9404 && !VOID_TYPE_P (TREE_TYPE (call)))
9405 /* An explicit call of the form "x->~X()" has type
9406 "void". However, on platforms where destructors
9407 return "this" (i.e., those where
9408 targetm.cxx.cdtor_returns_this is true), such calls
9409 will appear to have a return value of pointer type
9410 to the low-level call machinery. We do not want to
9411 change the low-level machinery, since we want to be
9412 able to optimize "delete f()" on such platforms as
9413 "operator delete(~X(f()))" (rather than generating
9414 "t = f(), ~X(t), operator delete (t)"). */
9415 call = build_nop (void_type_node, call);
9420 if (processing_template_decl && call != error_mark_node)
9422 bool cast_to_void = false;
9424 if (TREE_CODE (call) == COMPOUND_EXPR)
9425 call = TREE_OPERAND (call, 1);
9426 else if (TREE_CODE (call) == NOP_EXPR)
9428 cast_to_void = true;
9429 call = TREE_OPERAND (call, 0);
9431 if (INDIRECT_REF_P (call))
9432 call = TREE_OPERAND (call, 0);
9433 call = (build_min_non_dep_call_vec
9435 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
9436 orig_instance, orig_fns, NULL_TREE),
9438 SET_EXPR_LOCATION (call, input_location);
9439 call = convert_from_reference (call);
9441 call = build_nop (void_type_node, call);
9444 /* Free all the conversions we allocated. */
9445 obstack_free (&conversion_obstack, p);
9447 if (orig_args != NULL)
9448 release_tree_vector (orig_args);
9453 /* Wrapper for above. */
9456 build_new_method_call (tree instance, tree fns, vec<tree, va_gc> **args,
9457 tree conversion_path, int flags,
9458 tree *fn_p, tsubst_flags_t complain)
9461 bool subtime = timevar_cond_start (TV_OVERLOAD);
9462 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags,
9464 timevar_cond_stop (TV_OVERLOAD, subtime);
9468 /* Returns true iff standard conversion sequence ICS1 is a proper
9469 subsequence of ICS2. */
9472 is_subseq (conversion *ics1, conversion *ics2)
9474 /* We can assume that a conversion of the same code
9475 between the same types indicates a subsequence since we only get
9476 here if the types we are converting from are the same. */
9478 while (ics1->kind == ck_rvalue
9479 || ics1->kind == ck_lvalue)
9480 ics1 = next_conversion (ics1);
9484 while (ics2->kind == ck_rvalue
9485 || ics2->kind == ck_lvalue)
9486 ics2 = next_conversion (ics2);
9488 if (ics2->kind == ck_user
9489 || ics2->kind == ck_ambig
9490 || ics2->kind == ck_aggr
9491 || ics2->kind == ck_list
9492 || ics2->kind == ck_identity)
9493 /* At this point, ICS1 cannot be a proper subsequence of
9494 ICS2. We can get a USER_CONV when we are comparing the
9495 second standard conversion sequence of two user conversion
9499 ics2 = next_conversion (ics2);
9501 while (ics2->kind == ck_rvalue
9502 || ics2->kind == ck_lvalue)
9503 ics2 = next_conversion (ics2);
9505 if (ics2->kind == ics1->kind
9506 && same_type_p (ics2->type, ics1->type)
9507 && (ics1->kind == ck_identity
9508 || same_type_p (next_conversion (ics2)->type,
9509 next_conversion (ics1)->type)))
9514 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
9515 be any _TYPE nodes. */
9518 is_properly_derived_from (tree derived, tree base)
9520 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
9523 /* We only allow proper derivation here. The DERIVED_FROM_P macro
9524 considers every class derived from itself. */
9525 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
9526 && DERIVED_FROM_P (base, derived));
9529 /* We build the ICS for an implicit object parameter as a pointer
9530 conversion sequence. However, such a sequence should be compared
9531 as if it were a reference conversion sequence. If ICS is the
9532 implicit conversion sequence for an implicit object parameter,
9533 modify it accordingly. */
9536 maybe_handle_implicit_object (conversion **ics)
9540 /* [over.match.funcs]
9542 For non-static member functions, the type of the
9543 implicit object parameter is "reference to cv X"
9544 where X is the class of which the function is a
9545 member and cv is the cv-qualification on the member
9546 function declaration. */
9547 conversion *t = *ics;
9548 tree reference_type;
9550 /* The `this' parameter is a pointer to a class type. Make the
9551 implicit conversion talk about a reference to that same class
9553 reference_type = TREE_TYPE (t->type);
9554 reference_type = build_reference_type (reference_type);
9556 if (t->kind == ck_qual)
9557 t = next_conversion (t);
9558 if (t->kind == ck_ptr)
9559 t = next_conversion (t);
9560 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
9561 t = direct_reference_binding (reference_type, t);
9563 t->rvaluedness_matches_p = 0;
9568 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
9569 and return the initial reference binding conversion. Otherwise,
9570 leave *ICS unchanged and return NULL. */
9573 maybe_handle_ref_bind (conversion **ics)
9575 if ((*ics)->kind == ck_ref_bind)
9577 conversion *old_ics = *ics;
9578 *ics = next_conversion (old_ics);
9579 (*ics)->user_conv_p = old_ics->user_conv_p;
9586 /* Compare two implicit conversion sequences according to the rules set out in
9587 [over.ics.rank]. Return values:
9589 1: ics1 is better than ics2
9590 -1: ics2 is better than ics1
9591 0: ics1 and ics2 are indistinguishable */
9594 compare_ics (conversion *ics1, conversion *ics2)
9600 tree deref_from_type1 = NULL_TREE;
9601 tree deref_from_type2 = NULL_TREE;
9602 tree deref_to_type1 = NULL_TREE;
9603 tree deref_to_type2 = NULL_TREE;
9604 conversion_rank rank1, rank2;
9606 /* REF_BINDING is nonzero if the result of the conversion sequence
9607 is a reference type. In that case REF_CONV is the reference
9608 binding conversion. */
9609 conversion *ref_conv1;
9610 conversion *ref_conv2;
9612 /* Compare badness before stripping the reference conversion. */
9613 if (ics1->bad_p > ics2->bad_p)
9615 else if (ics1->bad_p < ics2->bad_p)
9618 /* Handle implicit object parameters. */
9619 maybe_handle_implicit_object (&ics1);
9620 maybe_handle_implicit_object (&ics2);
9622 /* Handle reference parameters. */
9623 ref_conv1 = maybe_handle_ref_bind (&ics1);
9624 ref_conv2 = maybe_handle_ref_bind (&ics2);
9626 /* List-initialization sequence L1 is a better conversion sequence than
9627 list-initialization sequence L2 if L1 converts to
9628 std::initializer_list<X> for some X and L2 does not. */
9629 if (ics1->kind == ck_list && ics2->kind != ck_list)
9631 if (ics2->kind == ck_list && ics1->kind != ck_list)
9636 When comparing the basic forms of implicit conversion sequences (as
9637 defined in _over.best.ics_)
9639 --a standard conversion sequence (_over.ics.scs_) is a better
9640 conversion sequence than a user-defined conversion sequence
9641 or an ellipsis conversion sequence, and
9643 --a user-defined conversion sequence (_over.ics.user_) is a
9644 better conversion sequence than an ellipsis conversion sequence
9645 (_over.ics.ellipsis_). */
9646 /* Use BAD_CONVERSION_RANK because we already checked for a badness
9647 mismatch. If both ICS are bad, we try to make a decision based on
9648 what would have happened if they'd been good. This is not an
9649 extension, we'll still give an error when we build up the call; this
9650 just helps us give a more helpful error message. */
9651 rank1 = BAD_CONVERSION_RANK (ics1);
9652 rank2 = BAD_CONVERSION_RANK (ics2);
9656 else if (rank1 < rank2)
9659 if (ics1->ellipsis_p)
9660 /* Both conversions are ellipsis conversions. */
9663 /* User-defined conversion sequence U1 is a better conversion sequence
9664 than another user-defined conversion sequence U2 if they contain the
9665 same user-defined conversion operator or constructor and if the sec-
9666 ond standard conversion sequence of U1 is better than the second
9667 standard conversion sequence of U2. */
9669 /* Handle list-conversion with the same code even though it isn't always
9670 ranked as a user-defined conversion and it doesn't have a second
9671 standard conversion sequence; it will still have the desired effect.
9672 Specifically, we need to do the reference binding comparison at the
9673 end of this function. */
9675 if (ics1->user_conv_p || ics1->kind == ck_list || ics1->kind == ck_aggr)
9680 for (t1 = ics1; t1->kind != ck_user; t1 = next_conversion (t1))
9681 if (t1->kind == ck_ambig || t1->kind == ck_aggr
9682 || t1->kind == ck_list)
9684 for (t2 = ics2; t2->kind != ck_user; t2 = next_conversion (t2))
9685 if (t2->kind == ck_ambig || t2->kind == ck_aggr
9686 || t2->kind == ck_list)
9689 if (t1->kind != t2->kind)
9691 else if (t1->kind == ck_user)
9693 tree f1 = t1->cand ? t1->cand->fn : t1->type;
9694 tree f2 = t2->cand ? t2->cand->fn : t2->type;
9700 /* For ambiguous or aggregate conversions, use the target type as
9701 a proxy for the conversion function. */
9702 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
9706 /* We can just fall through here, after setting up
9707 FROM_TYPE1 and FROM_TYPE2. */
9708 from_type1 = t1->type;
9709 from_type2 = t2->type;
9716 /* We're dealing with two standard conversion sequences.
9720 Standard conversion sequence S1 is a better conversion
9721 sequence than standard conversion sequence S2 if
9723 --S1 is a proper subsequence of S2 (comparing the conversion
9724 sequences in the canonical form defined by _over.ics.scs_,
9725 excluding any Lvalue Transformation; the identity
9726 conversion sequence is considered to be a subsequence of
9727 any non-identity conversion sequence */
9730 while (t1->kind != ck_identity)
9731 t1 = next_conversion (t1);
9732 from_type1 = t1->type;
9735 while (t2->kind != ck_identity)
9736 t2 = next_conversion (t2);
9737 from_type2 = t2->type;
9740 /* One sequence can only be a subsequence of the other if they start with
9741 the same type. They can start with different types when comparing the
9742 second standard conversion sequence in two user-defined conversion
9744 if (same_type_p (from_type1, from_type2))
9746 if (is_subseq (ics1, ics2))
9748 if (is_subseq (ics2, ics1))
9756 --the rank of S1 is better than the rank of S2 (by the rules
9759 Standard conversion sequences are ordered by their ranks: an Exact
9760 Match is a better conversion than a Promotion, which is a better
9761 conversion than a Conversion.
9763 Two conversion sequences with the same rank are indistinguishable
9764 unless one of the following rules applies:
9766 --A conversion that does not a convert a pointer, pointer to member,
9767 or std::nullptr_t to bool is better than one that does.
9769 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
9770 so that we do not have to check it explicitly. */
9771 if (ics1->rank < ics2->rank)
9773 else if (ics2->rank < ics1->rank)
9776 to_type1 = ics1->type;
9777 to_type2 = ics2->type;
9779 /* A conversion from scalar arithmetic type to complex is worse than a
9780 conversion between scalar arithmetic types. */
9781 if (same_type_p (from_type1, from_type2)
9782 && ARITHMETIC_TYPE_P (from_type1)
9783 && ARITHMETIC_TYPE_P (to_type1)
9784 && ARITHMETIC_TYPE_P (to_type2)
9785 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
9786 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
9788 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
9794 if (TYPE_PTR_P (from_type1)
9795 && TYPE_PTR_P (from_type2)
9796 && TYPE_PTR_P (to_type1)
9797 && TYPE_PTR_P (to_type2))
9799 deref_from_type1 = TREE_TYPE (from_type1);
9800 deref_from_type2 = TREE_TYPE (from_type2);
9801 deref_to_type1 = TREE_TYPE (to_type1);
9802 deref_to_type2 = TREE_TYPE (to_type2);
9804 /* The rules for pointers to members A::* are just like the rules
9805 for pointers A*, except opposite: if B is derived from A then
9806 A::* converts to B::*, not vice versa. For that reason, we
9807 switch the from_ and to_ variables here. */
9808 else if ((TYPE_PTRDATAMEM_P (from_type1) && TYPE_PTRDATAMEM_P (from_type2)
9809 && TYPE_PTRDATAMEM_P (to_type1) && TYPE_PTRDATAMEM_P (to_type2))
9810 || (TYPE_PTRMEMFUNC_P (from_type1)
9811 && TYPE_PTRMEMFUNC_P (from_type2)
9812 && TYPE_PTRMEMFUNC_P (to_type1)
9813 && TYPE_PTRMEMFUNC_P (to_type2)))
9815 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
9816 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
9817 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
9818 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
9821 if (deref_from_type1 != NULL_TREE
9822 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
9823 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
9825 /* This was one of the pointer or pointer-like conversions.
9829 --If class B is derived directly or indirectly from class A,
9830 conversion of B* to A* is better than conversion of B* to
9831 void*, and conversion of A* to void* is better than
9832 conversion of B* to void*. */
9833 if (VOID_TYPE_P (deref_to_type1)
9834 && VOID_TYPE_P (deref_to_type2))
9836 if (is_properly_derived_from (deref_from_type1,
9839 else if (is_properly_derived_from (deref_from_type2,
9843 else if (VOID_TYPE_P (deref_to_type1)
9844 || VOID_TYPE_P (deref_to_type2))
9846 if (same_type_p (deref_from_type1, deref_from_type2))
9848 if (VOID_TYPE_P (deref_to_type2))
9850 if (is_properly_derived_from (deref_from_type1,
9854 /* We know that DEREF_TO_TYPE1 is `void' here. */
9855 else if (is_properly_derived_from (deref_from_type1,
9860 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
9861 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
9865 --If class B is derived directly or indirectly from class A
9866 and class C is derived directly or indirectly from B,
9868 --conversion of C* to B* is better than conversion of C* to
9871 --conversion of B* to A* is better than conversion of C* to
9873 if (same_type_p (deref_from_type1, deref_from_type2))
9875 if (is_properly_derived_from (deref_to_type1,
9878 else if (is_properly_derived_from (deref_to_type2,
9882 else if (same_type_p (deref_to_type1, deref_to_type2))
9884 if (is_properly_derived_from (deref_from_type2,
9887 else if (is_properly_derived_from (deref_from_type1,
9893 else if (CLASS_TYPE_P (non_reference (from_type1))
9894 && same_type_p (from_type1, from_type2))
9896 tree from = non_reference (from_type1);
9900 --binding of an expression of type C to a reference of type
9901 B& is better than binding an expression of type C to a
9902 reference of type A&
9904 --conversion of C to B is better than conversion of C to A, */
9905 if (is_properly_derived_from (from, to_type1)
9906 && is_properly_derived_from (from, to_type2))
9908 if (is_properly_derived_from (to_type1, to_type2))
9910 else if (is_properly_derived_from (to_type2, to_type1))
9914 else if (CLASS_TYPE_P (non_reference (to_type1))
9915 && same_type_p (to_type1, to_type2))
9917 tree to = non_reference (to_type1);
9921 --binding of an expression of type B to a reference of type
9922 A& is better than binding an expression of type C to a
9923 reference of type A&,
9925 --conversion of B to A is better than conversion of C to A */
9926 if (is_properly_derived_from (from_type1, to)
9927 && is_properly_derived_from (from_type2, to))
9929 if (is_properly_derived_from (from_type2, from_type1))
9931 else if (is_properly_derived_from (from_type1, from_type2))
9938 --S1 and S2 differ only in their qualification conversion and yield
9939 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
9940 qualification signature of type T1 is a proper subset of the cv-
9941 qualification signature of type T2 */
9942 if (ics1->kind == ck_qual
9943 && ics2->kind == ck_qual
9944 && same_type_p (from_type1, from_type2))
9946 int result = comp_cv_qual_signature (to_type1, to_type2);
9953 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
9954 to an implicit object parameter of a non-static member function
9955 declared without a ref-qualifier, and either S1 binds an lvalue
9956 reference to an lvalue and S2 binds an rvalue reference or S1 binds an
9957 rvalue reference to an rvalue and S2 binds an lvalue reference (C++0x
9958 draft standard, 13.3.3.2)
9960 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
9961 types to which the references refer are the same type except for
9962 top-level cv-qualifiers, and the type to which the reference
9963 initialized by S2 refers is more cv-qualified than the type to
9964 which the reference initialized by S1 refers.
9966 DR 1328 [over.match.best]: the context is an initialization by
9967 conversion function for direct reference binding (13.3.1.6) of a
9968 reference to function type, the return type of F1 is the same kind of
9969 reference (i.e. lvalue or rvalue) as the reference being initialized,
9970 and the return type of F2 is not. */
9972 if (ref_conv1 && ref_conv2)
9974 if (!ref_conv1->this_p && !ref_conv2->this_p
9975 && (ref_conv1->rvaluedness_matches_p
9976 != ref_conv2->rvaluedness_matches_p)
9977 && (same_type_p (ref_conv1->type, ref_conv2->type)
9978 || (TYPE_REF_IS_RVALUE (ref_conv1->type)
9979 != TYPE_REF_IS_RVALUE (ref_conv2->type))))
9981 if (ref_conv1->bad_p
9982 && !same_type_p (TREE_TYPE (ref_conv1->type),
9983 TREE_TYPE (ref_conv2->type)))
9984 /* Don't prefer a bad conversion that drops cv-quals to a bad
9985 conversion with the wrong rvalueness. */
9987 return (ref_conv1->rvaluedness_matches_p
9988 - ref_conv2->rvaluedness_matches_p);
9991 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
9993 int q1 = cp_type_quals (TREE_TYPE (ref_conv1->type));
9994 int q2 = cp_type_quals (TREE_TYPE (ref_conv2->type));
9995 if (ref_conv1->bad_p)
9997 /* Prefer the one that drops fewer cv-quals. */
9998 tree ftype = next_conversion (ref_conv1)->type;
9999 int fquals = cp_type_quals (ftype);
10003 return comp_cv_qualification (q2, q1);
10007 /* Neither conversion sequence is better than the other. */
10011 /* The source type for this standard conversion sequence. */
10014 source_type (conversion *t)
10016 for (;; t = next_conversion (t))
10018 if (t->kind == ck_user
10019 || t->kind == ck_ambig
10020 || t->kind == ck_identity)
10023 gcc_unreachable ();
10026 /* Note a warning about preferring WINNER to LOSER. We do this by storing
10027 a pointer to LOSER and re-running joust to produce the warning if WINNER
10028 is actually used. */
10031 add_warning (struct z_candidate *winner, struct z_candidate *loser)
10033 candidate_warning *cw = (candidate_warning *)
10034 conversion_obstack_alloc (sizeof (candidate_warning));
10036 cw->next = winner->warnings;
10037 winner->warnings = cw;
10040 /* Compare two candidates for overloading as described in
10041 [over.match.best]. Return values:
10043 1: cand1 is better than cand2
10044 -1: cand2 is better than cand1
10045 0: cand1 and cand2 are indistinguishable */
10048 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn,
10049 tsubst_flags_t complain)
10052 int off1 = 0, off2 = 0;
10056 /* Candidates that involve bad conversions are always worse than those
10058 if (cand1->viable > cand2->viable)
10060 if (cand1->viable < cand2->viable)
10063 /* If we have two pseudo-candidates for conversions to the same type,
10064 or two candidates for the same function, arbitrarily pick one. */
10065 if (cand1->fn == cand2->fn
10066 && (IS_TYPE_OR_DECL_P (cand1->fn)))
10069 /* Prefer a non-deleted function over an implicitly deleted move
10070 constructor or assignment operator. This differs slightly from the
10071 wording for issue 1402 (which says the move op is ignored by overload
10072 resolution), but this way produces better error messages. */
10073 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
10074 && TREE_CODE (cand2->fn) == FUNCTION_DECL
10075 && DECL_DELETED_FN (cand1->fn) != DECL_DELETED_FN (cand2->fn))
10077 if (DECL_DELETED_FN (cand1->fn) && DECL_DEFAULTED_FN (cand1->fn)
10078 && move_fn_p (cand1->fn))
10080 if (DECL_DELETED_FN (cand2->fn) && DECL_DEFAULTED_FN (cand2->fn)
10081 && move_fn_p (cand2->fn))
10085 /* a viable function F1
10086 is defined to be a better function than another viable function F2 if
10087 for all arguments i, ICSi(F1) is not a worse conversion sequence than
10088 ICSi(F2), and then */
10090 /* for some argument j, ICSj(F1) is a better conversion sequence than
10093 /* For comparing static and non-static member functions, we ignore
10094 the implicit object parameter of the non-static function. The
10095 standard says to pretend that the static function has an object
10096 parm, but that won't work with operator overloading. */
10097 len = cand1->num_convs;
10098 if (len != cand2->num_convs)
10100 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
10101 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
10103 if (DECL_CONSTRUCTOR_P (cand1->fn)
10104 && is_list_ctor (cand1->fn) != is_list_ctor (cand2->fn))
10105 /* We're comparing a near-match list constructor and a near-match
10106 non-list constructor. Just treat them as unordered. */
10109 gcc_assert (static_1 != static_2);
10120 for (i = 0; i < len; ++i)
10122 conversion *t1 = cand1->convs[i + off1];
10123 conversion *t2 = cand2->convs[i + off2];
10124 int comp = compare_ics (t1, t2);
10128 if ((complain & tf_warning)
10130 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
10131 == cr_std + cr_promotion)
10132 && t1->kind == ck_std
10133 && t2->kind == ck_std
10134 && TREE_CODE (t1->type) == INTEGER_TYPE
10135 && TREE_CODE (t2->type) == INTEGER_TYPE
10136 && (TYPE_PRECISION (t1->type)
10137 == TYPE_PRECISION (t2->type))
10138 && (TYPE_UNSIGNED (next_conversion (t1)->type)
10139 || (TREE_CODE (next_conversion (t1)->type)
10140 == ENUMERAL_TYPE)))
10142 tree type = next_conversion (t1)->type;
10144 struct z_candidate *w, *l;
10146 type1 = t1->type, type2 = t2->type,
10147 w = cand1, l = cand2;
10149 type1 = t2->type, type2 = t1->type,
10150 w = cand2, l = cand1;
10154 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
10155 type, type1, type2);
10156 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
10159 add_warning (w, l);
10162 if (winner && comp != winner)
10171 /* warn about confusing overload resolution for user-defined conversions,
10172 either between a constructor and a conversion op, or between two
10174 if ((complain & tf_warning)
10175 && winner && warn_conversion && cand1->second_conv
10176 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
10177 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
10179 struct z_candidate *w, *l;
10180 bool give_warning = false;
10183 w = cand1, l = cand2;
10185 w = cand2, l = cand1;
10187 /* We don't want to complain about `X::operator T1 ()'
10188 beating `X::operator T2 () const', when T2 is a no less
10189 cv-qualified version of T1. */
10190 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
10191 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
10193 tree t = TREE_TYPE (TREE_TYPE (l->fn));
10194 tree f = TREE_TYPE (TREE_TYPE (w->fn));
10196 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
10201 if (!comp_ptr_ttypes (t, f))
10202 give_warning = true;
10205 give_warning = true;
10211 tree source = source_type (w->convs[0]);
10212 if (POINTER_TYPE_P (source))
10213 source = TREE_TYPE (source);
10214 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
10215 && warning (OPT_Wconversion, " for conversion from %qH to %qI",
10216 source, w->second_conv->type))
10218 inform (input_location, " because conversion sequence for the argument is better");
10222 add_warning (w, l);
10228 /* DR 495 moved this tiebreaker above the template ones. */
10229 /* or, if not that,
10230 the context is an initialization by user-defined conversion (see
10231 _dcl.init_ and _over.match.user_) and the standard conversion
10232 sequence from the return type of F1 to the destination type (i.e.,
10233 the type of the entity being initialized) is a better conversion
10234 sequence than the standard conversion sequence from the return type
10235 of F2 to the destination type. */
10237 if (cand1->second_conv)
10239 winner = compare_ics (cand1->second_conv, cand2->second_conv);
10244 /* or, if not that,
10245 F1 is a non-template function and F2 is a template function
10248 if (!cand1->template_decl && cand2->template_decl)
10250 else if (cand1->template_decl && !cand2->template_decl)
10253 /* or, if not that,
10254 F1 and F2 are template functions and the function template for F1 is
10255 more specialized than the template for F2 according to the partial
10258 if (cand1->template_decl && cand2->template_decl)
10260 winner = more_specialized_fn
10261 (TI_TEMPLATE (cand1->template_decl),
10262 TI_TEMPLATE (cand2->template_decl),
10263 /* [temp.func.order]: The presence of unused ellipsis and default
10264 arguments has no effect on the partial ordering of function
10265 templates. add_function_candidate() will not have
10266 counted the "this" argument for constructors. */
10267 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
10273 // or, if not that, F1 is more constrained than F2.
10274 if (flag_concepts && DECL_P (cand1->fn) && DECL_P (cand2->fn))
10276 winner = more_constrained (cand1->fn, cand2->fn);
10281 /* F1 is generated from a deduction-guide (13.3.1.8) and F2 is not */
10282 if (deduction_guide_p (cand1->fn))
10284 gcc_assert (deduction_guide_p (cand2->fn));
10285 /* We distinguish between candidates from an explicit deduction guide and
10286 candidates built from a constructor based on DECL_ARTIFICIAL. */
10287 int art1 = DECL_ARTIFICIAL (cand1->fn);
10288 int art2 = DECL_ARTIFICIAL (cand2->fn);
10290 return art2 - art1;
10294 /* Prefer the special copy guide over a declared copy/move
10296 if (copy_guide_p (cand1->fn))
10298 if (copy_guide_p (cand2->fn))
10301 /* Prefer a candidate generated from a non-template constructor. */
10302 int tg1 = template_guide_p (cand1->fn);
10303 int tg2 = template_guide_p (cand2->fn);
10309 /* F1 is a member of a class D, F2 is a member of a base class B of D, and
10310 for all arguments the corresponding parameters of F1 and F2 have the same
10311 type (CWG 2273/2277). */
10312 if (DECL_P (cand1->fn) && DECL_CLASS_SCOPE_P (cand1->fn)
10313 && !DECL_CONV_FN_P (cand1->fn)
10314 && DECL_P (cand2->fn) && DECL_CLASS_SCOPE_P (cand2->fn)
10315 && !DECL_CONV_FN_P (cand2->fn))
10317 tree base1 = DECL_CONTEXT (strip_inheriting_ctors (cand1->fn));
10318 tree base2 = DECL_CONTEXT (strip_inheriting_ctors (cand2->fn));
10320 bool used1 = false;
10321 bool used2 = false;
10322 if (base1 == base2)
10323 /* No difference. */;
10324 else if (DERIVED_FROM_P (base1, base2))
10326 else if (DERIVED_FROM_P (base2, base1))
10329 if (int diff = used2 - used1)
10331 for (i = 0; i < len; ++i)
10333 conversion *t1 = cand1->convs[i + off1];
10334 conversion *t2 = cand2->convs[i + off2];
10335 if (!same_type_p (t1->type, t2->type))
10343 /* Check whether we can discard a builtin candidate, either because we
10344 have two identical ones or matching builtin and non-builtin candidates.
10346 (Pedantically in the latter case the builtin which matched the user
10347 function should not be added to the overload set, but we spot it here.
10350 ... the builtin candidates include ...
10351 - do not have the same parameter type list as any non-template
10352 non-member candidate. */
10354 if (identifier_p (cand1->fn) || identifier_p (cand2->fn))
10356 for (i = 0; i < len; ++i)
10357 if (!same_type_p (cand1->convs[i]->type,
10358 cand2->convs[i]->type))
10360 if (i == cand1->num_convs)
10362 if (cand1->fn == cand2->fn)
10363 /* Two built-in candidates; arbitrarily pick one. */
10365 else if (identifier_p (cand1->fn))
10366 /* cand1 is built-in; prefer cand2. */
10369 /* cand2 is built-in; prefer cand1. */
10374 /* For candidates of a multi-versioned function, make the version with
10375 the highest priority win. This version will be checked for dispatching
10376 first. If this version can be inlined into the caller, the front-end
10377 will simply make a direct call to this function. */
10379 if (TREE_CODE (cand1->fn) == FUNCTION_DECL
10380 && DECL_FUNCTION_VERSIONED (cand1->fn)
10381 && TREE_CODE (cand2->fn) == FUNCTION_DECL
10382 && DECL_FUNCTION_VERSIONED (cand2->fn))
10384 tree f1 = TREE_TYPE (cand1->fn);
10385 tree f2 = TREE_TYPE (cand2->fn);
10386 tree p1 = TYPE_ARG_TYPES (f1);
10387 tree p2 = TYPE_ARG_TYPES (f2);
10389 /* Check if cand1->fn and cand2->fn are versions of the same function. It
10390 is possible that cand1->fn and cand2->fn are function versions but of
10391 different functions. Check types to see if they are versions of the same
10393 if (compparms (p1, p2)
10394 && same_type_p (TREE_TYPE (f1), TREE_TYPE (f2)))
10396 /* Always make the version with the higher priority, more
10397 specialized, win. */
10398 gcc_assert (targetm.compare_version_priority);
10399 if (targetm.compare_version_priority (cand1->fn, cand2->fn) >= 0)
10406 /* If the two function declarations represent the same function (this can
10407 happen with declarations in multiple scopes and arg-dependent lookup),
10408 arbitrarily choose one. But first make sure the default args we're
10410 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
10411 && equal_functions (cand1->fn, cand2->fn))
10413 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
10414 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
10416 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
10418 for (i = 0; i < len; ++i)
10420 /* Don't crash if the fn is variadic. */
10423 parms1 = TREE_CHAIN (parms1);
10424 parms2 = TREE_CHAIN (parms2);
10428 parms1 = TREE_CHAIN (parms1);
10430 parms2 = TREE_CHAIN (parms2);
10432 for (; parms1; ++i)
10434 if (!cp_tree_equal (TREE_PURPOSE (parms1),
10435 TREE_PURPOSE (parms2)))
10439 if (complain & tf_error)
10441 if (permerror (input_location,
10442 "default argument mismatch in "
10443 "overload resolution"))
10445 inform (DECL_SOURCE_LOCATION (cand1->fn),
10446 " candidate 1: %q#F", cand1->fn);
10447 inform (DECL_SOURCE_LOCATION (cand2->fn),
10448 " candidate 2: %q#F", cand2->fn);
10455 add_warning (cand1, cand2);
10458 parms1 = TREE_CHAIN (parms1);
10459 parms2 = TREE_CHAIN (parms2);
10467 /* Extension: If the worst conversion for one candidate is worse than the
10468 worst conversion for the other, take the first. */
10469 if (!pedantic && (complain & tf_warning_or_error))
10471 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
10472 struct z_candidate *w = 0, *l = 0;
10474 for (i = 0; i < len; ++i)
10476 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
10477 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
10478 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
10479 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
10482 winner = 1, w = cand1, l = cand2;
10484 winner = -1, w = cand2, l = cand1;
10487 /* Don't choose a deleted function over ambiguity. */
10488 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
10492 pedwarn (input_location, 0,
10493 "ISO C++ says that these are ambiguous, even "
10494 "though the worst conversion for the first is better than "
10495 "the worst conversion for the second:");
10496 print_z_candidate (input_location, _("candidate 1:"), w);
10497 print_z_candidate (input_location, _("candidate 2:"), l);
10500 add_warning (w, l);
10505 gcc_assert (!winner);
10509 /* Given a list of candidates for overloading, find the best one, if any.
10510 This algorithm has a worst case of O(2n) (winner is last), and a best
10511 case of O(n/2) (totally ambiguous); much better than a sorting
10514 static struct z_candidate *
10515 tourney (struct z_candidate *candidates, tsubst_flags_t complain)
10517 struct z_candidate *champ = candidates, *challenger;
10519 int champ_compared_to_predecessor = 0;
10521 /* Walk through the list once, comparing each current champ to the next
10522 candidate, knocking out a candidate or two with each comparison. */
10524 for (challenger = champ->next; challenger; )
10526 fate = joust (champ, challenger, 0, complain);
10528 challenger = challenger->next;
10533 champ = challenger->next;
10536 champ_compared_to_predecessor = 0;
10540 champ = challenger;
10541 champ_compared_to_predecessor = 1;
10544 challenger = champ->next;
10548 /* Make sure the champ is better than all the candidates it hasn't yet
10549 been compared to. */
10551 for (challenger = candidates;
10552 challenger != champ
10553 && !(champ_compared_to_predecessor && challenger->next == champ);
10554 challenger = challenger->next)
10556 fate = joust (champ, challenger, 0, complain);
10564 /* Returns nonzero if things of type FROM can be converted to TO. */
10567 can_convert (tree to, tree from, tsubst_flags_t complain)
10569 tree arg = NULL_TREE;
10570 /* implicit_conversion only considers user-defined conversions
10571 if it has an expression for the call argument list. */
10572 if (CLASS_TYPE_P (from) || CLASS_TYPE_P (to))
10573 arg = build1 (CAST_EXPR, from, NULL_TREE);
10574 return can_convert_arg (to, from, arg, LOOKUP_IMPLICIT, complain);
10577 /* Returns nonzero if things of type FROM can be converted to TO with a
10578 standard conversion. */
10581 can_convert_standard (tree to, tree from, tsubst_flags_t complain)
10583 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT, complain);
10586 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
10589 can_convert_arg (tree to, tree from, tree arg, int flags,
10590 tsubst_flags_t complain)
10596 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10597 p = conversion_obstack_alloc (0);
10598 /* We want to discard any access checks done for this test,
10599 as we might not be in the appropriate access context and
10600 we'll do the check again when we actually perform the
10602 push_deferring_access_checks (dk_deferred);
10604 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
10606 ok_p = (t && !t->bad_p);
10608 /* Discard the access checks now. */
10609 pop_deferring_access_checks ();
10610 /* Free all the conversions we allocated. */
10611 obstack_free (&conversion_obstack, p);
10616 /* Like can_convert_arg, but allows dubious conversions as well. */
10619 can_convert_arg_bad (tree to, tree from, tree arg, int flags,
10620 tsubst_flags_t complain)
10625 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10626 p = conversion_obstack_alloc (0);
10627 /* Try to perform the conversion. */
10628 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
10630 /* Free all the conversions we allocated. */
10631 obstack_free (&conversion_obstack, p);
10636 /* Convert EXPR to TYPE. Return the converted expression.
10638 Note that we allow bad conversions here because by the time we get to
10639 this point we are committed to doing the conversion. If we end up
10640 doing a bad conversion, convert_like will complain. */
10643 perform_implicit_conversion_flags (tree type, tree expr,
10644 tsubst_flags_t complain, int flags)
10648 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
10650 if (TREE_CODE (type) == REFERENCE_TYPE)
10651 expr = mark_lvalue_use (expr);
10653 expr = mark_rvalue_use (expr);
10655 if (error_operand_p (expr))
10656 return error_mark_node;
10658 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10659 p = conversion_obstack_alloc (0);
10661 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
10662 /*c_cast_p=*/false,
10667 if (complain & tf_error)
10669 /* If expr has unknown type, then it is an overloaded function.
10670 Call instantiate_type to get good error messages. */
10671 if (TREE_TYPE (expr) == unknown_type_node)
10672 instantiate_type (type, expr, complain);
10673 else if (invalid_nonstatic_memfn_p (loc, expr, complain))
10674 /* We gave an error. */;
10676 error_at (loc, "could not convert %qE from %qH to %qI", expr,
10677 TREE_TYPE (expr), type);
10679 expr = error_mark_node;
10681 else if (processing_template_decl && conv->kind != ck_identity)
10683 /* In a template, we are only concerned about determining the
10684 type of non-dependent expressions, so we do not have to
10685 perform the actual conversion. But for initializers, we
10686 need to be able to perform it at instantiation
10687 (or instantiate_non_dependent_expr) time. */
10688 expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
10689 if (!(flags & LOOKUP_ONLYCONVERTING))
10690 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
10693 expr = convert_like (conv, expr, complain);
10695 /* Free all the conversions we allocated. */
10696 obstack_free (&conversion_obstack, p);
10702 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
10704 return perform_implicit_conversion_flags (type, expr, complain,
10708 /* Convert EXPR to TYPE (as a direct-initialization) if that is
10709 permitted. If the conversion is valid, the converted expression is
10710 returned. Otherwise, NULL_TREE is returned, except in the case
10711 that TYPE is a class type; in that case, an error is issued. If
10712 C_CAST_P is true, then this direct-initialization is taking
10713 place as part of a static_cast being attempted as part of a C-style
10717 perform_direct_initialization_if_possible (tree type,
10720 tsubst_flags_t complain)
10725 if (type == error_mark_node || error_operand_p (expr))
10726 return error_mark_node;
10729 If the destination type is a (possibly cv-qualified) class type:
10731 -- If the initialization is direct-initialization ...,
10732 constructors are considered. ... If no constructor applies, or
10733 the overload resolution is ambiguous, the initialization is
10735 if (CLASS_TYPE_P (type))
10737 vec<tree, va_gc> *args = make_tree_vector_single (expr);
10738 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
10739 &args, type, LOOKUP_NORMAL, complain);
10740 release_tree_vector (args);
10741 return build_cplus_new (type, expr, complain);
10744 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10745 p = conversion_obstack_alloc (0);
10747 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
10749 LOOKUP_NORMAL, complain);
10750 if (!conv || conv->bad_p)
10752 else if (processing_template_decl && conv->kind != ck_identity)
10754 /* In a template, we are only concerned about determining the
10755 type of non-dependent expressions, so we do not have to
10756 perform the actual conversion. But for initializers, we
10757 need to be able to perform it at instantiation
10758 (or instantiate_non_dependent_expr) time. */
10759 expr = build1 (IMPLICIT_CONV_EXPR, type, expr);
10760 IMPLICIT_CONV_EXPR_DIRECT_INIT (expr) = true;
10763 expr = convert_like_real (conv, expr, NULL_TREE, 0,
10764 /*issue_conversion_warnings=*/false,
10768 /* Free all the conversions we allocated. */
10769 obstack_free (&conversion_obstack, p);
10774 /* When initializing a reference that lasts longer than a full-expression,
10775 this special rule applies:
10779 The temporary to which the reference is bound or the temporary
10780 that is the complete object to which the reference is bound
10781 persists for the lifetime of the reference.
10783 The temporaries created during the evaluation of the expression
10784 initializing the reference, except the temporary to which the
10785 reference is bound, are destroyed at the end of the
10786 full-expression in which they are created.
10788 In that case, we store the converted expression into a new
10789 VAR_DECL in a new scope.
10791 However, we want to be careful not to create temporaries when
10792 they are not required. For example, given:
10795 struct D : public B {};
10799 there is no need to copy the return value from "f"; we can just
10800 extend its lifetime. Similarly, given:
10803 struct T { operator S(); };
10807 we can extend the lifetime of the return value of the conversion
10810 The next several functions are involved in this lifetime extension. */
10812 /* DECL is a VAR_DECL or FIELD_DECL whose type is a REFERENCE_TYPE. The
10813 reference is being bound to a temporary. Create and return a new
10814 VAR_DECL with the indicated TYPE; this variable will store the value to
10815 which the reference is bound. */
10818 make_temporary_var_for_ref_to_temp (tree decl, tree type)
10820 tree var = create_temporary_var (type);
10822 /* Register the variable. */
10824 && (TREE_STATIC (decl) || CP_DECL_THREAD_LOCAL_P (decl)))
10826 /* Namespace-scope or local static; give it a mangled name. */
10827 /* FIXME share comdat with decl? */
10829 TREE_STATIC (var) = TREE_STATIC (decl);
10830 CP_DECL_THREAD_LOCAL_P (var) = CP_DECL_THREAD_LOCAL_P (decl);
10831 set_decl_tls_model (var, DECL_TLS_MODEL (decl));
10833 tree name = mangle_ref_init_variable (decl);
10834 DECL_NAME (var) = name;
10835 SET_DECL_ASSEMBLER_NAME (var, name);
10838 /* Create a new cleanup level if necessary. */
10839 maybe_push_cleanup_level (type);
10841 return pushdecl (var);
10844 /* EXPR is the initializer for a variable DECL of reference or
10845 std::initializer_list type. Create, push and return a new VAR_DECL
10846 for the initializer so that it will live as long as DECL. Any
10847 cleanup for the new variable is returned through CLEANUP, and the
10848 code to initialize the new variable is returned through INITP. */
10851 set_up_extended_ref_temp (tree decl, tree expr, vec<tree, va_gc> **cleanups,
10858 /* Create the temporary variable. */
10859 type = TREE_TYPE (expr);
10860 var = make_temporary_var_for_ref_to_temp (decl, type);
10861 layout_decl (var, 0);
10862 /* If the rvalue is the result of a function call it will be
10863 a TARGET_EXPR. If it is some other construct (such as a
10864 member access expression where the underlying object is
10865 itself the result of a function call), turn it into a
10866 TARGET_EXPR here. It is important that EXPR be a
10867 TARGET_EXPR below since otherwise the INIT_EXPR will
10868 attempt to make a bitwise copy of EXPR to initialize
10870 if (TREE_CODE (expr) != TARGET_EXPR)
10871 expr = get_target_expr (expr);
10873 if (TREE_CODE (decl) == FIELD_DECL
10874 && extra_warnings && !TREE_NO_WARNING (decl))
10876 warning (OPT_Wextra, "a temporary bound to %qD only persists "
10877 "until the constructor exits", decl);
10878 TREE_NO_WARNING (decl) = true;
10881 /* Recursively extend temps in this initializer. */
10882 TARGET_EXPR_INITIAL (expr)
10883 = extend_ref_init_temps (decl, TARGET_EXPR_INITIAL (expr), cleanups);
10885 /* Any reference temp has a non-trivial initializer. */
10886 DECL_NONTRIVIALLY_INITIALIZED_P (var) = true;
10888 /* If the initializer is constant, put it in DECL_INITIAL so we get
10889 static initialization and use in constant expressions. */
10890 init = maybe_constant_init (expr);
10891 /* As in store_init_value. */
10892 init = cp_fully_fold (init);
10893 if (TREE_CONSTANT (init))
10895 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
10897 /* 5.19 says that a constant expression can include an
10898 lvalue-rvalue conversion applied to "a glvalue of literal type
10899 that refers to a non-volatile temporary object initialized
10900 with a constant expression". Rather than try to communicate
10901 that this VAR_DECL is a temporary, just mark it constexpr.
10903 Currently this is only useful for initializer_list temporaries,
10904 since reference vars can't appear in constant expressions. */
10905 DECL_DECLARED_CONSTEXPR_P (var) = true;
10906 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
10907 TREE_CONSTANT (var) = true;
10909 DECL_INITIAL (var) = init;
10913 /* Create the INIT_EXPR that will initialize the temporary
10915 init = split_nonconstant_init (var, expr);
10916 if (at_function_scope_p ())
10918 add_decl_expr (var);
10920 if (TREE_STATIC (var))
10921 init = add_stmt_to_compound (init, register_dtor_fn (var));
10924 tree cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error);
10926 vec_safe_push (*cleanups, cleanup);
10929 /* We must be careful to destroy the temporary only
10930 after its initialization has taken place. If the
10931 initialization throws an exception, then the
10932 destructor should not be run. We cannot simply
10933 transform INIT into something like:
10935 (INIT, ({ CLEANUP_STMT; }))
10937 because emit_local_var always treats the
10938 initializer as a full-expression. Thus, the
10939 destructor would run too early; it would run at the
10940 end of initializing the reference variable, rather
10941 than at the end of the block enclosing the
10942 reference variable.
10944 The solution is to pass back a cleanup expression
10945 which the caller is responsible for attaching to
10946 the statement tree. */
10950 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
10951 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
10953 if (CP_DECL_THREAD_LOCAL_P (var))
10954 tls_aggregates = tree_cons (NULL_TREE, var,
10957 static_aggregates = tree_cons (NULL_TREE, var,
10958 static_aggregates);
10961 /* Check whether the dtor is callable. */
10962 cxx_maybe_build_cleanup (var, tf_warning_or_error);
10964 /* Avoid -Wunused-variable warning (c++/38958). */
10965 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
10967 TREE_USED (decl) = DECL_READ_P (decl) = true;
10973 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
10974 initializing a variable of that TYPE. */
10977 initialize_reference (tree type, tree expr,
10978 int flags, tsubst_flags_t complain)
10982 location_t loc = EXPR_LOC_OR_LOC (expr, input_location);
10984 if (type == error_mark_node || error_operand_p (expr))
10985 return error_mark_node;
10987 /* Get the high-water mark for the CONVERSION_OBSTACK. */
10988 p = conversion_obstack_alloc (0);
10990 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
10992 if (!conv || conv->bad_p)
10994 if (complain & tf_error)
10997 convert_like (conv, expr, complain);
10998 else if (!CP_TYPE_CONST_P (TREE_TYPE (type))
10999 && !TYPE_REF_IS_RVALUE (type)
11000 && !lvalue_p (expr))
11001 error_at (loc, "invalid initialization of non-const reference of "
11002 "type %qH from an rvalue of type %qI",
11003 type, TREE_TYPE (expr));
11005 error_at (loc, "invalid initialization of reference of type "
11006 "%qH from expression of type %qI", type,
11009 return error_mark_node;
11012 if (conv->kind == ck_ref_bind)
11013 /* Perform the conversion. */
11014 expr = convert_like (conv, expr, complain);
11015 else if (conv->kind == ck_ambig)
11016 /* We gave an error in build_user_type_conversion_1. */
11017 expr = error_mark_node;
11019 gcc_unreachable ();
11021 /* Free all the conversions we allocated. */
11022 obstack_free (&conversion_obstack, p);
11027 /* Subroutine of extend_ref_init_temps. Possibly extend one initializer,
11028 which is bound either to a reference or a std::initializer_list. */
11031 extend_ref_init_temps_1 (tree decl, tree init, vec<tree, va_gc> **cleanups)
11036 if (TREE_CODE (sub) == COMPOUND_EXPR)
11038 TREE_OPERAND (sub, 1)
11039 = extend_ref_init_temps_1 (decl, TREE_OPERAND (sub, 1), cleanups);
11042 if (TREE_CODE (sub) != ADDR_EXPR)
11044 /* Deal with binding to a subobject. */
11045 for (p = &TREE_OPERAND (sub, 0);
11046 (TREE_CODE (*p) == COMPONENT_REF
11047 || TREE_CODE (*p) == ARRAY_REF); )
11048 p = &TREE_OPERAND (*p, 0);
11049 if (TREE_CODE (*p) == TARGET_EXPR)
11051 tree subinit = NULL_TREE;
11052 *p = set_up_extended_ref_temp (decl, *p, cleanups, &subinit);
11053 recompute_tree_invariant_for_addr_expr (sub);
11055 init = fold_convert (TREE_TYPE (init), sub);
11057 init = build2 (COMPOUND_EXPR, TREE_TYPE (init), subinit, init);
11062 /* INIT is part of the initializer for DECL. If there are any
11063 reference or initializer lists being initialized, extend their
11064 lifetime to match that of DECL. */
11067 extend_ref_init_temps (tree decl, tree init, vec<tree, va_gc> **cleanups)
11069 tree type = TREE_TYPE (init);
11070 if (processing_template_decl)
11072 if (TREE_CODE (type) == REFERENCE_TYPE)
11073 init = extend_ref_init_temps_1 (decl, init, cleanups);
11077 if (TREE_CODE (ctor) == TARGET_EXPR)
11078 ctor = TARGET_EXPR_INITIAL (ctor);
11079 if (TREE_CODE (ctor) == CONSTRUCTOR)
11081 if (is_std_init_list (type))
11083 /* The temporary array underlying a std::initializer_list
11084 is handled like a reference temporary. */
11085 tree array = CONSTRUCTOR_ELT (ctor, 0)->value;
11086 array = extend_ref_init_temps_1 (decl, array, cleanups);
11087 CONSTRUCTOR_ELT (ctor, 0)->value = array;
11092 constructor_elt *p;
11093 vec<constructor_elt, va_gc> *elts = CONSTRUCTOR_ELTS (ctor);
11094 FOR_EACH_VEC_SAFE_ELT (elts, i, p)
11095 p->value = extend_ref_init_temps (decl, p->value, cleanups);
11097 recompute_constructor_flags (ctor);
11098 if (decl_maybe_constant_var_p (decl) && TREE_CONSTANT (ctor))
11099 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = true;
11106 /* Returns true iff an initializer for TYPE could contain temporaries that
11107 need to be extended because they are bound to references or
11108 std::initializer_list. */
11111 type_has_extended_temps (tree type)
11113 type = strip_array_types (type);
11114 if (TREE_CODE (type) == REFERENCE_TYPE)
11116 if (CLASS_TYPE_P (type))
11118 if (is_std_init_list (type))
11120 for (tree f = next_initializable_field (TYPE_FIELDS (type));
11121 f; f = next_initializable_field (DECL_CHAIN (f)))
11122 if (type_has_extended_temps (TREE_TYPE (f)))
11128 /* Returns true iff TYPE is some variant of std::initializer_list. */
11131 is_std_init_list (tree type)
11133 if (!TYPE_P (type))
11135 if (cxx_dialect == cxx98)
11137 /* Look through typedefs. */
11138 type = TYPE_MAIN_VARIANT (type);
11139 return (CLASS_TYPE_P (type)
11140 && CP_TYPE_CONTEXT (type) == std_node
11141 && init_list_identifier == DECL_NAME (TYPE_NAME (type)));
11144 /* Returns true iff DECL is a list constructor: i.e. a constructor which
11145 will accept an argument list of a single std::initializer_list<T>. */
11148 is_list_ctor (tree decl)
11150 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
11153 if (!args || args == void_list_node)
11156 arg = non_reference (TREE_VALUE (args));
11157 if (!is_std_init_list (arg))
11160 args = TREE_CHAIN (args);
11162 if (args && args != void_list_node && !TREE_PURPOSE (args))
11163 /* There are more non-defaulted parms. */
11169 #include "gt-cp-call.h"