1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com) and
6 modified by Brendan Kehoe (brendan@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
29 #include "coretypes.h"
38 #include "diagnostic.h"
42 #include "langhooks.h"
44 /* The various kinds of conversion. */
46 typedef enum conversion_kind {
62 /* The rank of the conversion. Order of the enumerals matters; better
63 conversions should come earlier in the list. */
65 typedef enum conversion_rank {
76 /* An implicit conversion sequence, in the sense of [over.best.ics].
77 The first conversion to be performed is at the end of the chain.
78 That conversion is always a cr_identity conversion. */
80 typedef struct conversion conversion;
82 /* The kind of conversion represented by this step. */
84 /* The rank of this conversion. */
86 BOOL_BITFIELD user_conv_p : 1;
87 BOOL_BITFIELD ellipsis_p : 1;
88 BOOL_BITFIELD this_p : 1;
89 BOOL_BITFIELD bad_p : 1;
90 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
91 temporary should be created to hold the result of the
93 BOOL_BITFIELD need_temporary_p : 1;
94 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
95 from a pointer-to-derived to pointer-to-base is being performed. */
96 BOOL_BITFIELD base_p : 1;
97 /* If KIND is ck_ref_bind, true when either an lvalue reference is
98 being bound to an lvalue expression or an rvalue reference is
99 being bound to an rvalue expression. */
100 BOOL_BITFIELD rvaluedness_matches_p: 1;
101 BOOL_BITFIELD check_narrowing: 1;
102 /* The type of the expression resulting from the conversion. */
105 /* The next conversion in the chain. Since the conversions are
106 arranged from outermost to innermost, the NEXT conversion will
107 actually be performed before this conversion. This variant is
108 used only when KIND is neither ck_identity nor ck_ambig. */
110 /* The expression at the beginning of the conversion chain. This
111 variant is used only if KIND is ck_identity or ck_ambig. */
113 /* The array of conversions for an initializer_list. */
116 /* The function candidate corresponding to this conversion
117 sequence. This field is only used if KIND is ck_user. */
118 struct z_candidate *cand;
121 #define CONVERSION_RANK(NODE) \
122 ((NODE)->bad_p ? cr_bad \
123 : (NODE)->ellipsis_p ? cr_ellipsis \
124 : (NODE)->user_conv_p ? cr_user \
127 static struct obstack conversion_obstack;
128 static bool conversion_obstack_initialized;
130 static struct z_candidate * tourney (struct z_candidate *);
131 static int equal_functions (tree, tree);
132 static int joust (struct z_candidate *, struct z_candidate *, bool);
133 static int compare_ics (conversion *, conversion *);
134 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
135 static tree build_java_interface_fn_ref (tree, tree);
136 #define convert_like(CONV, EXPR, COMPLAIN) \
137 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
138 /*issue_conversion_warnings=*/true, \
139 /*c_cast_p=*/false, (COMPLAIN))
140 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
141 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
142 /*issue_conversion_warnings=*/true, \
143 /*c_cast_p=*/false, (COMPLAIN))
144 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
145 bool, tsubst_flags_t);
146 static void op_error (enum tree_code, enum tree_code, tree, tree,
148 static tree build_object_call (tree, tree, tsubst_flags_t);
149 static tree resolve_args (tree);
150 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
151 static void print_z_candidate (const char *, struct z_candidate *);
152 static void print_z_candidates (struct z_candidate *);
153 static tree build_this (tree);
154 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
155 static bool any_strictly_viable (struct z_candidate *);
156 static struct z_candidate *add_template_candidate
157 (struct z_candidate **, tree, tree, tree, tree, tree,
158 tree, tree, int, unification_kind_t);
159 static struct z_candidate *add_template_candidate_real
160 (struct z_candidate **, tree, tree, tree, tree, tree,
161 tree, tree, int, tree, unification_kind_t);
162 static struct z_candidate *add_template_conv_candidate
163 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
164 static void add_builtin_candidates
165 (struct z_candidate **, enum tree_code, enum tree_code,
167 static void add_builtin_candidate
168 (struct z_candidate **, enum tree_code, enum tree_code,
169 tree, tree, tree, tree *, tree *, int);
170 static bool is_complete (tree);
171 static void build_builtin_candidate
172 (struct z_candidate **, tree, tree, tree, tree *, tree *,
174 static struct z_candidate *add_conv_candidate
175 (struct z_candidate **, tree, tree, tree, tree, tree);
176 static struct z_candidate *add_function_candidate
177 (struct z_candidate **, tree, tree, tree, tree, tree, int);
178 static conversion *implicit_conversion (tree, tree, tree, bool, int);
179 static conversion *standard_conversion (tree, tree, tree, bool, int);
180 static conversion *reference_binding (tree, tree, tree, bool, int);
181 static conversion *build_conv (conversion_kind, tree, conversion *);
182 static conversion *build_list_conv (tree, tree, int);
183 static bool is_subseq (conversion *, conversion *);
184 static conversion *maybe_handle_ref_bind (conversion **);
185 static void maybe_handle_implicit_object (conversion **);
186 static struct z_candidate *add_candidate
187 (struct z_candidate **, tree, tree, size_t,
188 conversion **, tree, tree, int);
189 static tree source_type (conversion *);
190 static void add_warning (struct z_candidate *, struct z_candidate *);
191 static bool reference_related_p (tree, tree);
192 static bool reference_compatible_p (tree, tree);
193 static conversion *convert_class_to_reference (tree, tree, tree);
194 static conversion *direct_reference_binding (tree, conversion *);
195 static bool promoted_arithmetic_type_p (tree);
196 static conversion *conditional_conversion (tree, tree);
197 static char *name_as_c_string (tree, tree, bool *);
198 static tree call_builtin_trap (void);
199 static tree prep_operand (tree);
200 static void add_candidates (tree, tree, tree, bool, tree, tree,
201 int, struct z_candidate **);
202 static conversion *merge_conversion_sequences (conversion *, conversion *);
203 static bool magic_varargs_p (tree);
204 static tree build_temp (tree, tree, int, diagnostic_t *);
206 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
207 NAME can take many forms... */
210 check_dtor_name (tree basetype, tree name)
212 /* Just accept something we've already complained about. */
213 if (name == error_mark_node)
216 if (TREE_CODE (name) == TYPE_DECL)
217 name = TREE_TYPE (name);
218 else if (TYPE_P (name))
220 else if (TREE_CODE (name) == IDENTIFIER_NODE)
222 if ((MAYBE_CLASS_TYPE_P (basetype)
223 && name == constructor_name (basetype))
224 || (TREE_CODE (basetype) == ENUMERAL_TYPE
225 && name == TYPE_IDENTIFIER (basetype)))
228 name = get_type_value (name);
234 template <class T> struct S { ~S(); };
238 NAME will be a class template. */
239 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
243 if (!name || name == error_mark_node)
245 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
248 /* We want the address of a function or method. We avoid creating a
249 pointer-to-member function. */
252 build_addr_func (tree function)
254 tree type = TREE_TYPE (function);
256 /* We have to do these by hand to avoid real pointer to member
258 if (TREE_CODE (type) == METHOD_TYPE)
260 if (TREE_CODE (function) == OFFSET_REF)
262 tree object = build_address (TREE_OPERAND (function, 0));
263 return get_member_function_from_ptrfunc (&object,
264 TREE_OPERAND (function, 1));
266 function = build_address (function);
269 function = decay_conversion (function);
274 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
275 POINTER_TYPE to those. Note, pointer to member function types
276 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
277 two variants. build_call_a is the primitive taking an array of
278 arguments, while build_call_n is a wrapper that handles varargs. */
281 build_call_n (tree function, int n, ...)
284 return build_call_a (function, 0, NULL);
287 tree *argarray = (tree *) alloca (n * sizeof (tree));
292 for (i = 0; i < n; i++)
293 argarray[i] = va_arg (ap, tree);
295 return build_call_a (function, n, argarray);
300 build_call_a (tree function, int n, tree *argarray)
302 int is_constructor = 0;
309 function = build_addr_func (function);
311 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
312 fntype = TREE_TYPE (TREE_TYPE (function));
313 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
314 || TREE_CODE (fntype) == METHOD_TYPE);
315 result_type = TREE_TYPE (fntype);
317 if (TREE_CODE (function) == ADDR_EXPR
318 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
320 decl = TREE_OPERAND (function, 0);
321 if (!TREE_USED (decl))
323 /* We invoke build_call directly for several library
324 functions. These may have been declared normally if
325 we're building libgcc, so we can't just check
327 gcc_assert (DECL_ARTIFICIAL (decl)
328 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
336 /* We check both the decl and the type; a function may be known not to
337 throw without being declared throw(). */
338 nothrow = ((decl && TREE_NOTHROW (decl))
339 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
341 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
342 current_function_returns_abnormally = 1;
344 if (decl && TREE_DEPRECATED (decl))
345 warn_deprecated_use (decl);
346 require_complete_eh_spec_types (fntype, decl);
348 if (decl && DECL_CONSTRUCTOR_P (decl))
351 /* Don't pass empty class objects by value. This is useful
352 for tags in STL, which are used to control overload resolution.
353 We don't need to handle other cases of copying empty classes. */
354 if (! decl || ! DECL_BUILT_IN (decl))
355 for (i = 0; i < n; i++)
356 if (is_empty_class (TREE_TYPE (argarray[i]))
357 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
359 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
360 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
364 function = build_call_array (result_type, function, n, argarray);
365 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
366 TREE_NOTHROW (function) = nothrow;
371 /* Build something of the form ptr->method (args)
372 or object.method (args). This can also build
373 calls to constructors, and find friends.
375 Member functions always take their class variable
378 INSTANCE is a class instance.
380 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
382 PARMS help to figure out what that NAME really refers to.
384 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
385 down to the real instance type to use for access checking. We need this
386 information to get protected accesses correct.
388 FLAGS is the logical disjunction of zero or more LOOKUP_
389 flags. See cp-tree.h for more info.
391 If this is all OK, calls build_function_call with the resolved
394 This function must also handle being called to perform
395 initialization, promotion/coercion of arguments, and
396 instantiation of default parameters.
398 Note that NAME may refer to an instance variable name. If
399 `operator()()' is defined for the type of that field, then we return
402 /* New overloading code. */
404 typedef struct z_candidate z_candidate;
406 typedef struct candidate_warning candidate_warning;
407 struct candidate_warning {
409 candidate_warning *next;
413 /* The FUNCTION_DECL that will be called if this candidate is
414 selected by overload resolution. */
416 /* The arguments to use when calling this function. */
418 /* The implicit conversion sequences for each of the arguments to
421 /* The number of implicit conversion sequences. */
423 /* If FN is a user-defined conversion, the standard conversion
424 sequence from the type returned by FN to the desired destination
426 conversion *second_conv;
428 /* If FN is a member function, the binfo indicating the path used to
429 qualify the name of FN at the call site. This path is used to
430 determine whether or not FN is accessible if it is selected by
431 overload resolution. The DECL_CONTEXT of FN will always be a
432 (possibly improper) base of this binfo. */
434 /* If FN is a non-static member function, the binfo indicating the
435 subobject to which the `this' pointer should be converted if FN
436 is selected by overload resolution. The type pointed to the by
437 the `this' pointer must correspond to the most derived class
438 indicated by the CONVERSION_PATH. */
439 tree conversion_path;
441 candidate_warning *warnings;
445 /* Returns true iff T is a null pointer constant in the sense of
449 null_ptr_cst_p (tree t)
453 A null pointer constant is an integral constant expression
454 (_expr.const_) rvalue of integer type that evaluates to zero. */
455 t = integral_constant_value (t);
458 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t))
461 if (!TREE_OVERFLOW (t))
467 /* Returns nonzero if PARMLIST consists of only default parms and/or
471 sufficient_parms_p (const_tree parmlist)
473 for (; parmlist && parmlist != void_list_node;
474 parmlist = TREE_CHAIN (parmlist))
475 if (!TREE_PURPOSE (parmlist))
480 /* Allocate N bytes of memory from the conversion obstack. The memory
481 is zeroed before being returned. */
484 conversion_obstack_alloc (size_t n)
487 if (!conversion_obstack_initialized)
489 gcc_obstack_init (&conversion_obstack);
490 conversion_obstack_initialized = true;
492 p = obstack_alloc (&conversion_obstack, n);
497 /* Dynamically allocate a conversion. */
500 alloc_conversion (conversion_kind kind)
503 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
508 #ifdef ENABLE_CHECKING
510 /* Make sure that all memory on the conversion obstack has been
514 validate_conversion_obstack (void)
516 if (conversion_obstack_initialized)
517 gcc_assert ((obstack_next_free (&conversion_obstack)
518 == obstack_base (&conversion_obstack)));
521 #endif /* ENABLE_CHECKING */
523 /* Dynamically allocate an array of N conversions. */
526 alloc_conversions (size_t n)
528 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
532 build_conv (conversion_kind code, tree type, conversion *from)
535 conversion_rank rank = CONVERSION_RANK (from);
537 /* Note that the caller is responsible for filling in t->cand for
538 user-defined conversions. */
539 t = alloc_conversion (code);
562 t->user_conv_p = (code == ck_user || from->user_conv_p);
563 t->bad_p = from->bad_p;
568 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
569 specialization of std::initializer_list<T>, if such a conversion is
573 build_list_conv (tree type, tree ctor, int flags)
575 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
576 unsigned len = CONSTRUCTOR_NELTS (ctor);
577 conversion **subconvs = alloc_conversions (len);
582 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
585 = implicit_conversion (elttype, TREE_TYPE (val), val,
593 t = alloc_conversion (ck_list);
595 t->u.list = subconvs;
598 for (i = 0; i < len; ++i)
600 conversion *sub = subconvs[i];
601 if (sub->rank > t->rank)
603 if (sub->user_conv_p)
604 t->user_conv_p = true;
612 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
613 aggregate class, if such a conversion is possible. */
616 build_aggr_conv (tree type, tree ctor, int flags)
618 unsigned HOST_WIDE_INT i = 0;
620 tree field = TYPE_FIELDS (type);
622 for (; field; field = TREE_CHAIN (field), ++i)
624 if (TREE_CODE (field) != FIELD_DECL)
626 if (i < CONSTRUCTOR_NELTS (ctor))
628 constructor_elt *ce = CONSTRUCTOR_ELT (ctor, i);
629 if (!can_convert_arg (TREE_TYPE (field), TREE_TYPE (ce->value),
633 else if (build_value_init (TREE_TYPE (field)) == error_mark_node)
637 c = alloc_conversion (ck_aggr);
640 c->user_conv_p = true;
645 /* Build a representation of the identity conversion from EXPR to
646 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
649 build_identity_conv (tree type, tree expr)
653 c = alloc_conversion (ck_identity);
660 /* Converting from EXPR to TYPE was ambiguous in the sense that there
661 were multiple user-defined conversions to accomplish the job.
662 Build a conversion that indicates that ambiguity. */
665 build_ambiguous_conv (tree type, tree expr)
669 c = alloc_conversion (ck_ambig);
677 strip_top_quals (tree t)
679 if (TREE_CODE (t) == ARRAY_TYPE)
681 return cp_build_qualified_type (t, 0);
684 /* Returns the standard conversion path (see [conv]) from type FROM to type
685 TO, if any. For proper handling of null pointer constants, you must
686 also pass the expression EXPR to convert from. If C_CAST_P is true,
687 this conversion is coming from a C-style cast. */
690 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
693 enum tree_code fcode, tcode;
695 bool fromref = false;
697 to = non_reference (to);
698 if (TREE_CODE (from) == REFERENCE_TYPE)
701 from = TREE_TYPE (from);
703 to = strip_top_quals (to);
704 from = strip_top_quals (from);
706 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
707 && expr && type_unknown_p (expr))
709 tsubst_flags_t tflags = tf_conv;
710 if (!(flags & LOOKUP_PROTECT))
711 tflags |= tf_no_access_control;
712 expr = instantiate_type (to, expr, tflags);
713 if (expr == error_mark_node)
715 from = TREE_TYPE (expr);
718 fcode = TREE_CODE (from);
719 tcode = TREE_CODE (to);
721 conv = build_identity_conv (from, expr);
722 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
724 from = type_decays_to (from);
725 fcode = TREE_CODE (from);
726 conv = build_conv (ck_lvalue, from, conv);
728 else if (fromref || (expr && lvalue_p (expr)))
733 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
736 from = strip_top_quals (bitfield_type);
737 fcode = TREE_CODE (from);
740 conv = build_conv (ck_rvalue, from, conv);
743 /* Allow conversion between `__complex__' data types. */
744 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
746 /* The standard conversion sequence to convert FROM to TO is
747 the standard conversion sequence to perform componentwise
749 conversion *part_conv = standard_conversion
750 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
754 conv = build_conv (part_conv->kind, to, conv);
755 conv->rank = part_conv->rank;
763 if (same_type_p (from, to))
766 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
767 && expr && null_ptr_cst_p (expr))
768 conv = build_conv (ck_std, to, conv);
769 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
770 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
772 /* For backwards brain damage compatibility, allow interconversion of
773 pointers and integers with a pedwarn. */
774 conv = build_conv (ck_std, to, conv);
777 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
779 /* For backwards brain damage compatibility, allow interconversion of
780 enums and integers with a pedwarn. */
781 conv = build_conv (ck_std, to, conv);
784 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
785 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
790 if (tcode == POINTER_TYPE
791 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
794 else if (VOID_TYPE_P (TREE_TYPE (to))
795 && !TYPE_PTRMEM_P (from)
796 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
798 from = build_pointer_type
799 (cp_build_qualified_type (void_type_node,
800 cp_type_quals (TREE_TYPE (from))));
801 conv = build_conv (ck_ptr, from, conv);
803 else if (TYPE_PTRMEM_P (from))
805 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
806 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
808 if (DERIVED_FROM_P (fbase, tbase)
809 && (same_type_ignoring_top_level_qualifiers_p
810 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
811 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
813 from = build_ptrmem_type (tbase,
814 TYPE_PTRMEM_POINTED_TO_TYPE (from));
815 conv = build_conv (ck_pmem, from, conv);
817 else if (!same_type_p (fbase, tbase))
820 else if (CLASS_TYPE_P (TREE_TYPE (from))
821 && CLASS_TYPE_P (TREE_TYPE (to))
824 An rvalue of type "pointer to cv D," where D is a
825 class type, can be converted to an rvalue of type
826 "pointer to cv B," where B is a base class (clause
827 _class.derived_) of D. If B is an inaccessible
828 (clause _class.access_) or ambiguous
829 (_class.member.lookup_) base class of D, a program
830 that necessitates this conversion is ill-formed.
831 Therefore, we use DERIVED_FROM_P, and do not check
832 access or uniqueness. */
833 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
836 cp_build_qualified_type (TREE_TYPE (to),
837 cp_type_quals (TREE_TYPE (from)));
838 from = build_pointer_type (from);
839 conv = build_conv (ck_ptr, from, conv);
843 if (tcode == POINTER_TYPE)
845 to_pointee = TREE_TYPE (to);
846 from_pointee = TREE_TYPE (from);
850 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
851 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
854 if (same_type_p (from, to))
856 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
857 /* In a C-style cast, we ignore CV-qualification because we
858 are allowed to perform a static_cast followed by a
860 conv = build_conv (ck_qual, to, conv);
861 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
862 conv = build_conv (ck_qual, to, conv);
863 else if (expr && string_conv_p (to, expr, 0))
864 /* converting from string constant to char *. */
865 conv = build_conv (ck_qual, to, conv);
866 else if (ptr_reasonably_similar (to_pointee, from_pointee))
868 conv = build_conv (ck_ptr, to, conv);
876 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
878 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
879 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
880 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
881 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
883 if (!DERIVED_FROM_P (fbase, tbase)
884 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
885 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
886 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
887 || cp_type_quals (fbase) != cp_type_quals (tbase))
890 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase));
891 from = build_ptrmemfunc_type (build_pointer_type (from));
892 conv = build_conv (ck_pmem, from, conv);
895 else if (tcode == BOOLEAN_TYPE)
899 An rvalue of arithmetic, unscoped enumeration, pointer, or
900 pointer to member type can be converted to an rvalue of type
902 if (ARITHMETIC_TYPE_P (from)
903 || UNSCOPED_ENUM_P (from)
904 || fcode == POINTER_TYPE
905 || TYPE_PTR_TO_MEMBER_P (from))
907 conv = build_conv (ck_std, to, conv);
908 if (fcode == POINTER_TYPE
909 || TYPE_PTRMEM_P (from)
910 || (TYPE_PTRMEMFUNC_P (from)
911 && conv->rank < cr_pbool))
912 conv->rank = cr_pbool;
918 /* We don't check for ENUMERAL_TYPE here because there are no standard
919 conversions to enum type. */
920 /* As an extension, allow conversion to complex type. */
921 else if (ARITHMETIC_TYPE_P (to))
923 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
924 || SCOPED_ENUM_P (from))
926 conv = build_conv (ck_std, to, conv);
928 /* Give this a better rank if it's a promotion. */
929 if (same_type_p (to, type_promotes_to (from))
930 && conv->u.next->rank <= cr_promotion)
931 conv->rank = cr_promotion;
933 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
934 && vector_types_convertible_p (from, to, false))
935 return build_conv (ck_std, to, conv);
936 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
937 && is_properly_derived_from (from, to))
939 if (conv->kind == ck_rvalue)
941 conv = build_conv (ck_base, to, conv);
942 /* The derived-to-base conversion indicates the initialization
943 of a parameter with base type from an object of a derived
944 type. A temporary object is created to hold the result of
945 the conversion unless we're binding directly to a reference. */
946 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
951 if (flags & LOOKUP_NO_NARROWING)
952 conv->check_narrowing = true;
957 /* Returns nonzero if T1 is reference-related to T2. */
960 reference_related_p (tree t1, tree t2)
962 t1 = TYPE_MAIN_VARIANT (t1);
963 t2 = TYPE_MAIN_VARIANT (t2);
967 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
968 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
970 return (same_type_p (t1, t2)
971 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
972 && DERIVED_FROM_P (t1, t2)));
975 /* Returns nonzero if T1 is reference-compatible with T2. */
978 reference_compatible_p (tree t1, tree t2)
982 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
983 reference-related to T2 and cv1 is the same cv-qualification as,
984 or greater cv-qualification than, cv2. */
985 return (reference_related_p (t1, t2)
986 && at_least_as_qualified_p (t1, t2));
989 /* Determine whether or not the EXPR (of class type S) can be
990 converted to T as in [over.match.ref]. */
993 convert_class_to_reference (tree reference_type, tree s, tree expr)
999 struct z_candidate *candidates;
1000 struct z_candidate *cand;
1003 conversions = lookup_conversions (s);
1009 Assuming that "cv1 T" is the underlying type of the reference
1010 being initialized, and "cv S" is the type of the initializer
1011 expression, with S a class type, the candidate functions are
1012 selected as follows:
1014 --The conversion functions of S and its base classes are
1015 considered. Those that are not hidden within S and yield type
1016 "reference to cv2 T2", where "cv1 T" is reference-compatible
1017 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1019 The argument list has one argument, which is the initializer
1024 /* Conceptually, we should take the address of EXPR and put it in
1025 the argument list. Unfortunately, however, that can result in
1026 error messages, which we should not issue now because we are just
1027 trying to find a conversion operator. Therefore, we use NULL,
1028 cast to the appropriate type. */
1029 arglist = build_int_cst (build_pointer_type (s), 0);
1030 arglist = build_tree_list (NULL_TREE, arglist);
1032 t = TREE_TYPE (reference_type);
1036 tree fns = TREE_VALUE (conversions);
1038 for (; fns; fns = OVL_NEXT (fns))
1040 tree f = OVL_CURRENT (fns);
1041 tree t2 = TREE_TYPE (TREE_TYPE (f));
1045 /* If this is a template function, try to get an exact
1047 if (TREE_CODE (f) == TEMPLATE_DECL)
1049 cand = add_template_candidate (&candidates,
1055 TREE_PURPOSE (conversions),
1061 /* Now, see if the conversion function really returns
1062 an lvalue of the appropriate type. From the
1063 point of view of unification, simply returning an
1064 rvalue of the right type is good enough. */
1066 t2 = TREE_TYPE (TREE_TYPE (f));
1067 if (TREE_CODE (t2) != REFERENCE_TYPE
1068 || !reference_compatible_p (t, TREE_TYPE (t2)))
1070 candidates = candidates->next;
1075 else if (TREE_CODE (t2) == REFERENCE_TYPE
1076 && reference_compatible_p (t, TREE_TYPE (t2)))
1077 cand = add_function_candidate (&candidates, f, s, arglist,
1079 TREE_PURPOSE (conversions),
1084 conversion *identity_conv;
1085 /* Build a standard conversion sequence indicating the
1086 binding from the reference type returned by the
1087 function to the desired REFERENCE_TYPE. */
1089 = build_identity_conv (TREE_TYPE (TREE_TYPE
1090 (TREE_TYPE (cand->fn))),
1093 = (direct_reference_binding
1094 (reference_type, identity_conv));
1095 cand->second_conv->rvaluedness_matches_p
1096 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1097 == TYPE_REF_IS_RVALUE (reference_type);
1098 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1101 conversions = TREE_CHAIN (conversions);
1104 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1105 /* If none of the conversion functions worked out, let our caller
1110 cand = tourney (candidates);
1114 /* Now that we know that this is the function we're going to use fix
1115 the dummy first argument. */
1116 cand->args = tree_cons (NULL_TREE,
1118 TREE_CHAIN (cand->args));
1120 /* Build a user-defined conversion sequence representing the
1122 conv = build_conv (ck_user,
1123 TREE_TYPE (TREE_TYPE (cand->fn)),
1124 build_identity_conv (TREE_TYPE (expr), expr));
1127 /* Merge it with the standard conversion sequence from the
1128 conversion function's return type to the desired type. */
1129 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1131 if (cand->viable == -1)
1134 return cand->second_conv;
1137 /* A reference of the indicated TYPE is being bound directly to the
1138 expression represented by the implicit conversion sequence CONV.
1139 Return a conversion sequence for this binding. */
1142 direct_reference_binding (tree type, conversion *conv)
1146 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1147 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1149 t = TREE_TYPE (type);
1153 When a parameter of reference type binds directly
1154 (_dcl.init.ref_) to an argument expression, the implicit
1155 conversion sequence is the identity conversion, unless the
1156 argument expression has a type that is a derived class of the
1157 parameter type, in which case the implicit conversion sequence is
1158 a derived-to-base Conversion.
1160 If the parameter binds directly to the result of applying a
1161 conversion function to the argument expression, the implicit
1162 conversion sequence is a user-defined conversion sequence
1163 (_over.ics.user_), with the second standard conversion sequence
1164 either an identity conversion or, if the conversion function
1165 returns an entity of a type that is a derived class of the
1166 parameter type, a derived-to-base conversion. */
1167 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1169 /* Represent the derived-to-base conversion. */
1170 conv = build_conv (ck_base, t, conv);
1171 /* We will actually be binding to the base-class subobject in
1172 the derived class, so we mark this conversion appropriately.
1173 That way, convert_like knows not to generate a temporary. */
1174 conv->need_temporary_p = false;
1176 return build_conv (ck_ref_bind, type, conv);
1179 /* Returns the conversion path from type FROM to reference type TO for
1180 purposes of reference binding. For lvalue binding, either pass a
1181 reference type to FROM or an lvalue expression to EXPR. If the
1182 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1183 the conversion returned. If C_CAST_P is true, this
1184 conversion is coming from a C-style cast. */
1187 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1189 conversion *conv = NULL;
1190 tree to = TREE_TYPE (rto);
1195 cp_lvalue_kind lvalue_p = clk_none;
1197 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1199 expr = instantiate_type (to, expr, tf_none);
1200 if (expr == error_mark_node)
1202 from = TREE_TYPE (expr);
1205 if (TREE_CODE (from) == REFERENCE_TYPE)
1207 /* Anything with reference type is an lvalue. */
1208 lvalue_p = clk_ordinary;
1209 from = TREE_TYPE (from);
1212 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1214 maybe_warn_cpp0x ("extended initializer lists");
1215 conv = implicit_conversion (to, from, expr, c_cast_p,
1217 if (!CLASS_TYPE_P (to)
1218 && CONSTRUCTOR_NELTS (expr) == 1)
1220 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1221 if (error_operand_p (expr))
1223 from = TREE_TYPE (expr);
1227 if (lvalue_p == clk_none && expr)
1228 lvalue_p = real_lvalue_p (expr);
1231 if ((lvalue_p & clk_bitfield) != 0)
1232 tfrom = unlowered_expr_type (expr);
1234 /* Figure out whether or not the types are reference-related and
1235 reference compatible. We have do do this after stripping
1236 references from FROM. */
1237 related_p = reference_related_p (to, tfrom);
1238 /* If this is a C cast, first convert to an appropriately qualified
1239 type, so that we can later do a const_cast to the desired type. */
1240 if (related_p && c_cast_p
1241 && !at_least_as_qualified_p (to, tfrom))
1242 to = build_qualified_type (to, cp_type_quals (tfrom));
1243 compatible_p = reference_compatible_p (to, tfrom);
1245 /* Directly bind reference when target expression's type is compatible with
1246 the reference and expression is an lvalue. In DR391, the wording in
1247 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1248 const and rvalue references to rvalues of compatible class type. */
1251 || (!(flags & LOOKUP_NO_TEMP_BIND)
1252 && (CP_TYPE_CONST_NON_VOLATILE_P(to) || TYPE_REF_IS_RVALUE (rto))
1253 && CLASS_TYPE_P (from))))
1257 If the initializer expression
1259 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1260 is reference-compatible with "cv2 T2,"
1262 the reference is bound directly to the initializer expression
1266 If the initializer expression is an rvalue, with T2 a class type,
1267 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1268 is bound to the object represented by the rvalue or to a sub-object
1269 within that object. */
1271 conv = build_identity_conv (tfrom, expr);
1272 conv = direct_reference_binding (rto, conv);
1274 if (flags & LOOKUP_PREFER_RVALUE)
1275 /* The top-level caller requested that we pretend that the lvalue
1276 be treated as an rvalue. */
1277 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1279 conv->rvaluedness_matches_p
1280 = (TYPE_REF_IS_RVALUE (rto) == !lvalue_p);
1282 if ((lvalue_p & clk_bitfield) != 0
1283 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1284 /* For the purposes of overload resolution, we ignore the fact
1285 this expression is a bitfield or packed field. (In particular,
1286 [over.ics.ref] says specifically that a function with a
1287 non-const reference parameter is viable even if the
1288 argument is a bitfield.)
1290 However, when we actually call the function we must create
1291 a temporary to which to bind the reference. If the
1292 reference is volatile, or isn't const, then we cannot make
1293 a temporary, so we just issue an error when the conversion
1295 conv->need_temporary_p = true;
1299 /* [class.conv.fct] A conversion function is never used to convert a
1300 (possibly cv-qualified) object to the (possibly cv-qualified) same
1301 object type (or a reference to it), to a (possibly cv-qualified) base
1302 class of that type (or a reference to it).... */
1303 else if (CLASS_TYPE_P (from) && !related_p
1304 && !(flags & LOOKUP_NO_CONVERSION))
1308 If the initializer expression
1310 -- has a class type (i.e., T2 is a class type) can be
1311 implicitly converted to an lvalue of type "cv3 T3," where
1312 "cv1 T1" is reference-compatible with "cv3 T3". (this
1313 conversion is selected by enumerating the applicable
1314 conversion functions (_over.match.ref_) and choosing the
1315 best one through overload resolution. (_over.match_).
1317 the reference is bound to the lvalue result of the conversion
1318 in the second case. */
1319 conv = convert_class_to_reference (rto, from, expr);
1324 /* From this point on, we conceptually need temporaries, even if we
1325 elide them. Only the cases above are "direct bindings". */
1326 if (flags & LOOKUP_NO_TEMP_BIND)
1331 When a parameter of reference type is not bound directly to an
1332 argument expression, the conversion sequence is the one required
1333 to convert the argument expression to the underlying type of the
1334 reference according to _over.best.ics_. Conceptually, this
1335 conversion sequence corresponds to copy-initializing a temporary
1336 of the underlying type with the argument expression. Any
1337 difference in top-level cv-qualification is subsumed by the
1338 initialization itself and does not constitute a conversion. */
1342 Otherwise, the reference shall be to a non-volatile const type.
1344 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1345 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1350 Otherwise, a temporary of type "cv1 T1" is created and
1351 initialized from the initializer expression using the rules for a
1352 non-reference copy initialization. If T1 is reference-related to
1353 T2, cv1 must be the same cv-qualification as, or greater
1354 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1355 if (related_p && !at_least_as_qualified_p (to, from))
1358 /* We're generating a temporary now, but don't bind any more in the
1359 conversion (specifically, don't slice the temporary returned by a
1360 conversion operator). */
1361 flags |= LOOKUP_NO_TEMP_BIND;
1364 conv = implicit_conversion (to, from, expr, c_cast_p,
1369 conv = build_conv (ck_ref_bind, rto, conv);
1370 /* This reference binding, unlike those above, requires the
1371 creation of a temporary. */
1372 conv->need_temporary_p = true;
1373 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1378 /* Returns the implicit conversion sequence (see [over.ics]) from type
1379 FROM to type TO. The optional expression EXPR may affect the
1380 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1381 true, this conversion is coming from a C-style cast. */
1384 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1389 if (from == error_mark_node || to == error_mark_node
1390 || expr == error_mark_node)
1393 if (TREE_CODE (to) == REFERENCE_TYPE)
1394 conv = reference_binding (to, from, expr, c_cast_p, flags);
1396 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1401 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1403 if (is_std_init_list (to))
1404 return build_list_conv (to, expr, flags);
1406 /* Allow conversion from an initializer-list with one element to a
1408 if (SCALAR_TYPE_P (to))
1410 int nelts = CONSTRUCTOR_NELTS (expr);
1414 elt = integer_zero_node;
1415 else if (nelts == 1)
1416 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1418 elt = error_mark_node;
1420 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1424 conv->check_narrowing = true;
1425 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1426 /* Too many levels of braces, i.e. '{{1}}'. */
1433 if (expr != NULL_TREE
1434 && (MAYBE_CLASS_TYPE_P (from)
1435 || MAYBE_CLASS_TYPE_P (to))
1436 && (flags & LOOKUP_NO_CONVERSION) == 0)
1438 struct z_candidate *cand;
1439 int convflags = ((flags & LOOKUP_NO_TEMP_BIND)
1440 |LOOKUP_ONLYCONVERTING);
1442 if (CLASS_TYPE_P (to)
1443 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1444 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1445 return build_aggr_conv (to, expr, flags);
1447 cand = build_user_type_conversion_1 (to, expr, convflags);
1449 conv = cand->second_conv;
1451 /* We used to try to bind a reference to a temporary here, but that
1452 is now handled after the recursive call to this function at the end
1453 of reference_binding. */
1460 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1463 static struct z_candidate *
1464 add_candidate (struct z_candidate **candidates,
1466 size_t num_convs, conversion **convs,
1467 tree access_path, tree conversion_path,
1470 struct z_candidate *cand = (struct z_candidate *)
1471 conversion_obstack_alloc (sizeof (struct z_candidate));
1475 cand->convs = convs;
1476 cand->num_convs = num_convs;
1477 cand->access_path = access_path;
1478 cand->conversion_path = conversion_path;
1479 cand->viable = viable;
1480 cand->next = *candidates;
1486 /* Create an overload candidate for the function or method FN called with
1487 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1488 to implicit_conversion.
1490 CTYPE, if non-NULL, is the type we want to pretend this function
1491 comes from for purposes of overload resolution. */
1493 static struct z_candidate *
1494 add_function_candidate (struct z_candidate **candidates,
1495 tree fn, tree ctype, tree arglist,
1496 tree access_path, tree conversion_path,
1499 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1502 tree parmnode, argnode;
1506 /* At this point we should not see any functions which haven't been
1507 explicitly declared, except for friend functions which will have
1508 been found using argument dependent lookup. */
1509 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1511 /* The `this', `in_chrg' and VTT arguments to constructors are not
1512 considered in overload resolution. */
1513 if (DECL_CONSTRUCTOR_P (fn))
1515 parmlist = skip_artificial_parms_for (fn, parmlist);
1516 orig_arglist = arglist;
1517 arglist = skip_artificial_parms_for (fn, arglist);
1520 orig_arglist = arglist;
1522 len = list_length (arglist);
1523 convs = alloc_conversions (len);
1525 /* 13.3.2 - Viable functions [over.match.viable]
1526 First, to be a viable function, a candidate function shall have enough
1527 parameters to agree in number with the arguments in the list.
1529 We need to check this first; otherwise, checking the ICSes might cause
1530 us to produce an ill-formed template instantiation. */
1532 parmnode = parmlist;
1533 for (i = 0; i < len; ++i)
1535 if (parmnode == NULL_TREE || parmnode == void_list_node)
1537 parmnode = TREE_CHAIN (parmnode);
1540 if (i < len && parmnode)
1543 /* Make sure there are default args for the rest of the parms. */
1544 else if (!sufficient_parms_p (parmnode))
1550 /* Second, for F to be a viable function, there shall exist for each
1551 argument an implicit conversion sequence that converts that argument
1552 to the corresponding parameter of F. */
1554 parmnode = parmlist;
1557 for (i = 0; i < len; ++i)
1559 tree arg = TREE_VALUE (argnode);
1560 tree argtype = lvalue_type (arg);
1564 if (parmnode == void_list_node)
1567 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1568 && ! DECL_CONSTRUCTOR_P (fn));
1572 tree parmtype = TREE_VALUE (parmnode);
1575 /* The type of the implicit object parameter ('this') for
1576 overload resolution is not always the same as for the
1577 function itself; conversion functions are considered to
1578 be members of the class being converted, and functions
1579 introduced by a using-declaration are considered to be
1580 members of the class that uses them.
1582 Since build_over_call ignores the ICS for the `this'
1583 parameter, we can just change the parm type. */
1584 if (ctype && is_this)
1587 = build_qualified_type (ctype,
1588 TYPE_QUALS (TREE_TYPE (parmtype)));
1589 parmtype = build_pointer_type (parmtype);
1592 if ((flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1593 && ctype && i == 0 && DECL_COPY_CONSTRUCTOR_P (fn))
1594 lflags |= LOOKUP_NO_CONVERSION;
1596 t = implicit_conversion (parmtype, argtype, arg,
1597 /*c_cast_p=*/false, lflags);
1601 t = build_identity_conv (argtype, arg);
1602 t->ellipsis_p = true;
1619 parmnode = TREE_CHAIN (parmnode);
1620 argnode = TREE_CHAIN (argnode);
1624 return add_candidate (candidates, fn, orig_arglist, len, convs,
1625 access_path, conversion_path, viable);
1628 /* Create an overload candidate for the conversion function FN which will
1629 be invoked for expression OBJ, producing a pointer-to-function which
1630 will in turn be called with the argument list ARGLIST, and add it to
1631 CANDIDATES. FLAGS is passed on to implicit_conversion.
1633 Actually, we don't really care about FN; we care about the type it
1634 converts to. There may be multiple conversion functions that will
1635 convert to that type, and we rely on build_user_type_conversion_1 to
1636 choose the best one; so when we create our candidate, we record the type
1637 instead of the function. */
1639 static struct z_candidate *
1640 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1641 tree arglist, tree access_path, tree conversion_path)
1643 tree totype = TREE_TYPE (TREE_TYPE (fn));
1644 int i, len, viable, flags;
1645 tree parmlist, parmnode, argnode;
1648 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1649 parmlist = TREE_TYPE (parmlist);
1650 parmlist = TYPE_ARG_TYPES (parmlist);
1652 len = list_length (arglist) + 1;
1653 convs = alloc_conversions (len);
1654 parmnode = parmlist;
1657 flags = LOOKUP_NORMAL;
1659 /* Don't bother looking up the same type twice. */
1660 if (*candidates && (*candidates)->fn == totype)
1663 for (i = 0; i < len; ++i)
1665 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1666 tree argtype = lvalue_type (arg);
1670 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1672 else if (parmnode == void_list_node)
1675 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1676 /*c_cast_p=*/false, flags);
1679 t = build_identity_conv (argtype, arg);
1680 t->ellipsis_p = true;
1694 parmnode = TREE_CHAIN (parmnode);
1695 argnode = TREE_CHAIN (argnode);
1701 if (!sufficient_parms_p (parmnode))
1704 return add_candidate (candidates, totype, arglist, len, convs,
1705 access_path, conversion_path, viable);
1709 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1710 tree type1, tree type2, tree *args, tree *argtypes,
1722 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1723 convs = alloc_conversions (num_convs);
1725 for (i = 0; i < 2; ++i)
1730 t = implicit_conversion (types[i], argtypes[i], args[i],
1731 /*c_cast_p=*/false, flags);
1735 /* We need something for printing the candidate. */
1736 t = build_identity_conv (types[i], NULL_TREE);
1743 /* For COND_EXPR we rearranged the arguments; undo that now. */
1746 convs[2] = convs[1];
1747 convs[1] = convs[0];
1748 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1749 /*c_cast_p=*/false, flags);
1756 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1758 /*access_path=*/NULL_TREE,
1759 /*conversion_path=*/NULL_TREE,
1764 is_complete (tree t)
1766 return COMPLETE_TYPE_P (complete_type (t));
1769 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1772 promoted_arithmetic_type_p (tree type)
1776 In this section, the term promoted integral type is used to refer
1777 to those integral types which are preserved by integral promotion
1778 (including e.g. int and long but excluding e.g. char).
1779 Similarly, the term promoted arithmetic type refers to promoted
1780 integral types plus floating types. */
1781 return ((INTEGRAL_TYPE_P (type)
1782 && same_type_p (type_promotes_to (type), type))
1783 || TREE_CODE (type) == REAL_TYPE);
1786 /* Create any builtin operator overload candidates for the operator in
1787 question given the converted operand types TYPE1 and TYPE2. The other
1788 args are passed through from add_builtin_candidates to
1789 build_builtin_candidate.
1791 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1792 If CODE is requires candidates operands of the same type of the kind
1793 of which TYPE1 and TYPE2 are, we add both candidates
1794 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1797 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1798 enum tree_code code2, tree fnname, tree type1,
1799 tree type2, tree *args, tree *argtypes, int flags)
1803 case POSTINCREMENT_EXPR:
1804 case POSTDECREMENT_EXPR:
1805 args[1] = integer_zero_node;
1806 type2 = integer_type_node;
1815 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1816 and VQ is either volatile or empty, there exist candidate operator
1817 functions of the form
1818 VQ T& operator++(VQ T&);
1819 T operator++(VQ T&, int);
1820 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1821 type other than bool, and VQ is either volatile or empty, there exist
1822 candidate operator functions of the form
1823 VQ T& operator--(VQ T&);
1824 T operator--(VQ T&, int);
1825 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1826 complete object type, and VQ is either volatile or empty, there exist
1827 candidate operator functions of the form
1828 T*VQ& operator++(T*VQ&);
1829 T*VQ& operator--(T*VQ&);
1830 T* operator++(T*VQ&, int);
1831 T* operator--(T*VQ&, int); */
1833 case POSTDECREMENT_EXPR:
1834 case PREDECREMENT_EXPR:
1835 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1837 case POSTINCREMENT_EXPR:
1838 case PREINCREMENT_EXPR:
1839 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1841 type1 = build_reference_type (type1);
1846 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1847 exist candidate operator functions of the form
1851 8 For every function type T, there exist candidate operator functions of
1853 T& operator*(T*); */
1856 if (TREE_CODE (type1) == POINTER_TYPE
1857 && (TYPE_PTROB_P (type1)
1858 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1862 /* 9 For every type T, there exist candidate operator functions of the form
1865 10For every promoted arithmetic type T, there exist candidate operator
1866 functions of the form
1870 case UNARY_PLUS_EXPR: /* unary + */
1871 if (TREE_CODE (type1) == POINTER_TYPE)
1874 if (ARITHMETIC_TYPE_P (type1))
1878 /* 11For every promoted integral type T, there exist candidate operator
1879 functions of the form
1883 if (INTEGRAL_TYPE_P (type1))
1887 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1888 is the same type as C2 or is a derived class of C2, T is a complete
1889 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1890 there exist candidate operator functions of the form
1891 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1892 where CV12 is the union of CV1 and CV2. */
1895 if (TREE_CODE (type1) == POINTER_TYPE
1896 && TYPE_PTR_TO_MEMBER_P (type2))
1898 tree c1 = TREE_TYPE (type1);
1899 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1901 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
1902 && (TYPE_PTRMEMFUNC_P (type2)
1903 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1908 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1909 didate operator functions of the form
1914 bool operator<(L, R);
1915 bool operator>(L, R);
1916 bool operator<=(L, R);
1917 bool operator>=(L, R);
1918 bool operator==(L, R);
1919 bool operator!=(L, R);
1920 where LR is the result of the usual arithmetic conversions between
1923 14For every pair of types T and I, where T is a cv-qualified or cv-
1924 unqualified complete object type and I is a promoted integral type,
1925 there exist candidate operator functions of the form
1926 T* operator+(T*, I);
1927 T& operator[](T*, I);
1928 T* operator-(T*, I);
1929 T* operator+(I, T*);
1930 T& operator[](I, T*);
1932 15For every T, where T is a pointer to complete object type, there exist
1933 candidate operator functions of the form112)
1934 ptrdiff_t operator-(T, T);
1936 16For every pointer or enumeration type T, there exist candidate operator
1937 functions of the form
1938 bool operator<(T, T);
1939 bool operator>(T, T);
1940 bool operator<=(T, T);
1941 bool operator>=(T, T);
1942 bool operator==(T, T);
1943 bool operator!=(T, T);
1945 17For every pointer to member type T, there exist candidate operator
1946 functions of the form
1947 bool operator==(T, T);
1948 bool operator!=(T, T); */
1951 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1953 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1955 type2 = ptrdiff_type_node;
1959 case TRUNC_DIV_EXPR:
1960 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1966 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1967 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1969 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1974 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1986 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1988 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1990 if (TREE_CODE (type1) == ENUMERAL_TYPE
1991 && TREE_CODE (type2) == ENUMERAL_TYPE)
1993 if (TYPE_PTR_P (type1)
1994 && null_ptr_cst_p (args[1])
1995 && !uses_template_parms (type1))
2000 if (null_ptr_cst_p (args[0])
2001 && TYPE_PTR_P (type2)
2002 && !uses_template_parms (type2))
2010 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2013 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
2015 type1 = ptrdiff_type_node;
2018 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
2020 type2 = ptrdiff_type_node;
2025 /* 18For every pair of promoted integral types L and R, there exist candi-
2026 date operator functions of the form
2033 where LR is the result of the usual arithmetic conversions between
2036 case TRUNC_MOD_EXPR:
2042 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
2046 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2047 type, VQ is either volatile or empty, and R is a promoted arithmetic
2048 type, there exist candidate operator functions of the form
2049 VQ L& operator=(VQ L&, R);
2050 VQ L& operator*=(VQ L&, R);
2051 VQ L& operator/=(VQ L&, R);
2052 VQ L& operator+=(VQ L&, R);
2053 VQ L& operator-=(VQ L&, R);
2055 20For every pair T, VQ), where T is any type and VQ is either volatile
2056 or empty, there exist candidate operator functions of the form
2057 T*VQ& operator=(T*VQ&, T*);
2059 21For every pair T, VQ), where T is a pointer to member type and VQ is
2060 either volatile or empty, there exist candidate operator functions of
2062 VQ T& operator=(VQ T&, T);
2064 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2065 unqualified complete object type, VQ is either volatile or empty, and
2066 I is a promoted integral type, there exist candidate operator func-
2068 T*VQ& operator+=(T*VQ&, I);
2069 T*VQ& operator-=(T*VQ&, I);
2071 23For every triple L, VQ, R), where L is an integral or enumeration
2072 type, VQ is either volatile or empty, and R is a promoted integral
2073 type, there exist candidate operator functions of the form
2075 VQ L& operator%=(VQ L&, R);
2076 VQ L& operator<<=(VQ L&, R);
2077 VQ L& operator>>=(VQ L&, R);
2078 VQ L& operator&=(VQ L&, R);
2079 VQ L& operator^=(VQ L&, R);
2080 VQ L& operator|=(VQ L&, R); */
2087 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
2089 type2 = ptrdiff_type_node;
2093 case TRUNC_DIV_EXPR:
2094 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2098 case TRUNC_MOD_EXPR:
2104 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
2109 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2111 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2112 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2113 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2114 || ((TYPE_PTRMEMFUNC_P (type1)
2115 || TREE_CODE (type1) == POINTER_TYPE)
2116 && null_ptr_cst_p (args[1])))
2126 type1 = build_reference_type (type1);
2132 For every pair of promoted arithmetic types L and R, there
2133 exist candidate operator functions of the form
2135 LR operator?(bool, L, R);
2137 where LR is the result of the usual arithmetic conversions
2138 between types L and R.
2140 For every type T, where T is a pointer or pointer-to-member
2141 type, there exist candidate operator functions of the form T
2142 operator?(bool, T, T); */
2144 if (promoted_arithmetic_type_p (type1)
2145 && promoted_arithmetic_type_p (type2))
2149 /* Otherwise, the types should be pointers. */
2150 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2151 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2154 /* We don't check that the two types are the same; the logic
2155 below will actually create two candidates; one in which both
2156 parameter types are TYPE1, and one in which both parameter
2164 /* If we're dealing with two pointer types or two enumeral types,
2165 we need candidates for both of them. */
2166 if (type2 && !same_type_p (type1, type2)
2167 && TREE_CODE (type1) == TREE_CODE (type2)
2168 && (TREE_CODE (type1) == REFERENCE_TYPE
2169 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2170 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2171 || TYPE_PTRMEMFUNC_P (type1)
2172 || MAYBE_CLASS_TYPE_P (type1)
2173 || TREE_CODE (type1) == ENUMERAL_TYPE))
2175 build_builtin_candidate
2176 (candidates, fnname, type1, type1, args, argtypes, flags);
2177 build_builtin_candidate
2178 (candidates, fnname, type2, type2, args, argtypes, flags);
2182 build_builtin_candidate
2183 (candidates, fnname, type1, type2, args, argtypes, flags);
2187 type_decays_to (tree type)
2189 if (TREE_CODE (type) == ARRAY_TYPE)
2190 return build_pointer_type (TREE_TYPE (type));
2191 if (TREE_CODE (type) == FUNCTION_TYPE)
2192 return build_pointer_type (type);
2196 /* There are three conditions of builtin candidates:
2198 1) bool-taking candidates. These are the same regardless of the input.
2199 2) pointer-pair taking candidates. These are generated for each type
2200 one of the input types converts to.
2201 3) arithmetic candidates. According to the standard, we should generate
2202 all of these, but I'm trying not to...
2204 Here we generate a superset of the possible candidates for this particular
2205 case. That is a subset of the full set the standard defines, plus some
2206 other cases which the standard disallows. add_builtin_candidate will
2207 filter out the invalid set. */
2210 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2211 enum tree_code code2, tree fnname, tree *args,
2216 tree type, argtypes[3];
2217 /* TYPES[i] is the set of possible builtin-operator parameter types
2218 we will consider for the Ith argument. These are represented as
2219 a TREE_LIST; the TREE_VALUE of each node is the potential
2223 for (i = 0; i < 3; ++i)
2226 argtypes[i] = unlowered_expr_type (args[i]);
2228 argtypes[i] = NULL_TREE;
2233 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2234 and VQ is either volatile or empty, there exist candidate operator
2235 functions of the form
2236 VQ T& operator++(VQ T&); */
2238 case POSTINCREMENT_EXPR:
2239 case PREINCREMENT_EXPR:
2240 case POSTDECREMENT_EXPR:
2241 case PREDECREMENT_EXPR:
2246 /* 24There also exist candidate operator functions of the form
2247 bool operator!(bool);
2248 bool operator&&(bool, bool);
2249 bool operator||(bool, bool); */
2251 case TRUTH_NOT_EXPR:
2252 build_builtin_candidate
2253 (candidates, fnname, boolean_type_node,
2254 NULL_TREE, args, argtypes, flags);
2257 case TRUTH_ORIF_EXPR:
2258 case TRUTH_ANDIF_EXPR:
2259 build_builtin_candidate
2260 (candidates, fnname, boolean_type_node,
2261 boolean_type_node, args, argtypes, flags);
2283 types[0] = types[1] = NULL_TREE;
2285 for (i = 0; i < 2; ++i)
2289 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2293 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2296 convs = lookup_conversions (argtypes[i]);
2298 if (code == COND_EXPR)
2300 if (real_lvalue_p (args[i]))
2301 types[i] = tree_cons
2302 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2304 types[i] = tree_cons
2305 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2311 for (; convs; convs = TREE_CHAIN (convs))
2313 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2316 && (TREE_CODE (type) != REFERENCE_TYPE
2317 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2320 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2321 types[i] = tree_cons (NULL_TREE, type, types[i]);
2323 type = non_reference (type);
2324 if (i != 0 || ! ref1)
2326 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2327 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2328 types[i] = tree_cons (NULL_TREE, type, types[i]);
2329 if (INTEGRAL_TYPE_P (type))
2330 type = type_promotes_to (type);
2333 if (! value_member (type, types[i]))
2334 types[i] = tree_cons (NULL_TREE, type, types[i]);
2339 if (code == COND_EXPR && real_lvalue_p (args[i]))
2340 types[i] = tree_cons
2341 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2342 type = non_reference (argtypes[i]);
2343 if (i != 0 || ! ref1)
2345 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2346 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2347 types[i] = tree_cons (NULL_TREE, type, types[i]);
2348 if (INTEGRAL_TYPE_P (type))
2349 type = type_promotes_to (type);
2351 types[i] = tree_cons (NULL_TREE, type, types[i]);
2355 /* Run through the possible parameter types of both arguments,
2356 creating candidates with those parameter types. */
2357 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2360 for (type = types[1]; type; type = TREE_CHAIN (type))
2361 add_builtin_candidate
2362 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2363 TREE_VALUE (type), args, argtypes, flags);
2365 add_builtin_candidate
2366 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2367 NULL_TREE, args, argtypes, flags);
2372 /* If TMPL can be successfully instantiated as indicated by
2373 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2375 TMPL is the template. EXPLICIT_TARGS are any explicit template
2376 arguments. ARGLIST is the arguments provided at the call-site.
2377 The RETURN_TYPE is the desired type for conversion operators. If
2378 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2379 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2380 add_conv_candidate. */
2382 static struct z_candidate*
2383 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2384 tree ctype, tree explicit_targs, tree arglist,
2385 tree return_type, tree access_path,
2386 tree conversion_path, int flags, tree obj,
2387 unification_kind_t strict)
2389 int ntparms = DECL_NTPARMS (tmpl);
2390 tree targs = make_tree_vec (ntparms);
2391 tree args_without_in_chrg = arglist;
2392 struct z_candidate *cand;
2396 /* We don't do deduction on the in-charge parameter, the VTT
2397 parameter or 'this'. */
2398 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2399 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2401 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2402 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2403 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2404 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2406 i = fn_type_unification (tmpl, explicit_targs, targs,
2407 args_without_in_chrg,
2408 return_type, strict, flags);
2413 fn = instantiate_template (tmpl, targs, tf_none);
2414 if (fn == error_mark_node)
2419 A member function template is never instantiated to perform the
2420 copy of a class object to an object of its class type.
2422 It's a little unclear what this means; the standard explicitly
2423 does allow a template to be used to copy a class. For example,
2428 template <class T> A(const T&);
2431 void g () { A a (f ()); }
2433 the member template will be used to make the copy. The section
2434 quoted above appears in the paragraph that forbids constructors
2435 whose only parameter is (a possibly cv-qualified variant of) the
2436 class type, and a logical interpretation is that the intent was
2437 to forbid the instantiation of member templates which would then
2439 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2441 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2442 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2447 if (obj != NULL_TREE)
2448 /* Aha, this is a conversion function. */
2449 cand = add_conv_candidate (candidates, fn, obj, access_path,
2450 conversion_path, arglist);
2452 cand = add_function_candidate (candidates, fn, ctype,
2453 arglist, access_path,
2454 conversion_path, flags);
2455 if (DECL_TI_TEMPLATE (fn) != tmpl)
2456 /* This situation can occur if a member template of a template
2457 class is specialized. Then, instantiate_template might return
2458 an instantiation of the specialization, in which case the
2459 DECL_TI_TEMPLATE field will point at the original
2460 specialization. For example:
2462 template <class T> struct S { template <class U> void f(U);
2463 template <> void f(int) {}; };
2467 Here, TMPL will be template <class U> S<double>::f(U).
2468 And, instantiate template will give us the specialization
2469 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2470 for this will point at template <class T> template <> S<T>::f(int),
2471 so that we can find the definition. For the purposes of
2472 overload resolution, however, we want the original TMPL. */
2473 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2475 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2481 static struct z_candidate *
2482 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2483 tree explicit_targs, tree arglist, tree return_type,
2484 tree access_path, tree conversion_path, int flags,
2485 unification_kind_t strict)
2488 add_template_candidate_real (candidates, tmpl, ctype,
2489 explicit_targs, arglist, return_type,
2490 access_path, conversion_path,
2491 flags, NULL_TREE, strict);
2495 static struct z_candidate *
2496 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2497 tree obj, tree arglist, tree return_type,
2498 tree access_path, tree conversion_path)
2501 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2502 arglist, return_type, access_path,
2503 conversion_path, 0, obj, DEDUCE_CONV);
2506 /* The CANDS are the set of candidates that were considered for
2507 overload resolution. Return the set of viable candidates. If none
2508 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2509 is true if a candidate should be considered viable only if it is
2512 static struct z_candidate*
2513 splice_viable (struct z_candidate *cands,
2517 struct z_candidate *viable;
2518 struct z_candidate **last_viable;
2519 struct z_candidate **cand;
2522 last_viable = &viable;
2523 *any_viable_p = false;
2528 struct z_candidate *c = *cand;
2529 if (strict_p ? c->viable == 1 : c->viable)
2534 last_viable = &c->next;
2535 *any_viable_p = true;
2541 return viable ? viable : cands;
2545 any_strictly_viable (struct z_candidate *cands)
2547 for (; cands; cands = cands->next)
2548 if (cands->viable == 1)
2553 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2554 words, it is about to become the "this" pointer for a member
2555 function call. Take the address of the object. */
2558 build_this (tree obj)
2560 /* In a template, we are only concerned about the type of the
2561 expression, so we can take a shortcut. */
2562 if (processing_template_decl)
2563 return build_address (obj);
2565 return cp_build_unary_op (ADDR_EXPR, obj, 0, tf_warning_or_error);
2568 /* Returns true iff functions are equivalent. Equivalent functions are
2569 not '==' only if one is a function-local extern function or if
2570 both are extern "C". */
2573 equal_functions (tree fn1, tree fn2)
2575 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2576 || DECL_EXTERN_C_FUNCTION_P (fn1))
2577 return decls_match (fn1, fn2);
2581 /* Print information about one overload candidate CANDIDATE. MSGSTR
2582 is the text to print before the candidate itself.
2584 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2585 to have been run through gettext by the caller. This wart makes
2586 life simpler in print_z_candidates and for the translators. */
2589 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2591 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2593 if (candidate->num_convs == 3)
2594 inform (input_location, "%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2595 candidate->convs[0]->type,
2596 candidate->convs[1]->type,
2597 candidate->convs[2]->type);
2598 else if (candidate->num_convs == 2)
2599 inform (input_location, "%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2600 candidate->convs[0]->type,
2601 candidate->convs[1]->type);
2603 inform (input_location, "%s %D(%T) <built-in>", msgstr, candidate->fn,
2604 candidate->convs[0]->type);
2606 else if (TYPE_P (candidate->fn))
2607 inform (input_location, "%s %T <conversion>", msgstr, candidate->fn);
2608 else if (candidate->viable == -1)
2609 inform (input_location, "%s %+#D <near match>", msgstr, candidate->fn);
2611 inform (input_location, "%s %+#D", msgstr, candidate->fn);
2615 print_z_candidates (struct z_candidate *candidates)
2618 struct z_candidate *cand1;
2619 struct z_candidate **cand2;
2621 /* There may be duplicates in the set of candidates. We put off
2622 checking this condition as long as possible, since we have no way
2623 to eliminate duplicates from a set of functions in less than n^2
2624 time. Now we are about to emit an error message, so it is more
2625 permissible to go slowly. */
2626 for (cand1 = candidates; cand1; cand1 = cand1->next)
2628 tree fn = cand1->fn;
2629 /* Skip builtin candidates and conversion functions. */
2630 if (TREE_CODE (fn) != FUNCTION_DECL)
2632 cand2 = &cand1->next;
2635 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2636 && equal_functions (fn, (*cand2)->fn))
2637 *cand2 = (*cand2)->next;
2639 cand2 = &(*cand2)->next;
2646 str = _("candidates are:");
2647 print_z_candidate (str, candidates);
2648 if (candidates->next)
2650 /* Indent successive candidates by the width of the translation
2651 of the above string. */
2652 size_t len = gcc_gettext_width (str) + 1;
2653 char *spaces = (char *) alloca (len);
2654 memset (spaces, ' ', len-1);
2655 spaces[len - 1] = '\0';
2657 candidates = candidates->next;
2660 print_z_candidate (spaces, candidates);
2661 candidates = candidates->next;
2667 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2668 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2669 the result of the conversion function to convert it to the final
2670 desired type. Merge the two sequences into a single sequence,
2671 and return the merged sequence. */
2674 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2678 gcc_assert (user_seq->kind == ck_user);
2680 /* Find the end of the second conversion sequence. */
2682 while ((*t)->kind != ck_identity)
2683 t = &((*t)->u.next);
2685 /* Replace the identity conversion with the user conversion
2689 /* The entire sequence is a user-conversion sequence. */
2690 std_seq->user_conv_p = true;
2695 /* Returns the best overload candidate to perform the requested
2696 conversion. This function is used for three the overloading situations
2697 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2698 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2699 per [dcl.init.ref], so we ignore temporary bindings. */
2701 static struct z_candidate *
2702 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2704 struct z_candidate *candidates, *cand;
2705 tree fromtype = TREE_TYPE (expr);
2706 tree ctors = NULL_TREE;
2707 tree conv_fns = NULL_TREE;
2708 conversion *conv = NULL;
2709 tree args = NULL_TREE;
2713 /* We represent conversion within a hierarchy using RVALUE_CONV and
2714 BASE_CONV, as specified by [over.best.ics]; these become plain
2715 constructor calls, as specified in [dcl.init]. */
2716 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
2717 || !DERIVED_FROM_P (totype, fromtype));
2719 if (MAYBE_CLASS_TYPE_P (totype))
2720 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2722 if (MAYBE_CLASS_TYPE_P (fromtype))
2724 tree to_nonref = non_reference (totype);
2725 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
2726 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
2727 && DERIVED_FROM_P (to_nonref, fromtype)))
2729 /* [class.conv.fct] A conversion function is never used to
2730 convert a (possibly cv-qualified) object to the (possibly
2731 cv-qualified) same object type (or a reference to it), to a
2732 (possibly cv-qualified) base class of that type (or a
2733 reference to it)... */
2736 conv_fns = lookup_conversions (fromtype);
2740 flags |= LOOKUP_NO_CONVERSION;
2742 /* It's OK to bind a temporary for converting constructor arguments, but
2743 not in converting the return value of a conversion operator. */
2744 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
2745 flags &= ~LOOKUP_NO_TEMP_BIND;
2751 ctors = BASELINK_FUNCTIONS (ctors);
2753 t = build_int_cst (build_pointer_type (totype), 0);
2754 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
2755 && !TYPE_HAS_LIST_CTOR (totype))
2757 args = ctor_to_list (expr);
2758 /* We still allow more conversions within an init-list. */
2759 flags = ((flags & ~LOOKUP_NO_CONVERSION)
2760 /* But not for the copy ctor. */
2761 |LOOKUP_NO_COPY_CTOR_CONVERSION
2762 |LOOKUP_NO_NARROWING);
2765 args = build_tree_list (NULL_TREE, expr);
2766 /* We should never try to call the abstract or base constructor
2768 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2769 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2770 args = tree_cons (NULL_TREE, t, args);
2772 for (; ctors; ctors = OVL_NEXT (ctors))
2774 tree ctor = OVL_CURRENT (ctors);
2775 if (DECL_NONCONVERTING_P (ctor)
2776 && !BRACE_ENCLOSED_INITIALIZER_P (expr))
2779 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2780 cand = add_template_candidate (&candidates, ctor, totype,
2781 NULL_TREE, args, NULL_TREE,
2782 TYPE_BINFO (totype),
2783 TYPE_BINFO (totype),
2787 cand = add_function_candidate (&candidates, ctor, totype,
2788 args, TYPE_BINFO (totype),
2789 TYPE_BINFO (totype),
2794 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2796 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2797 set, then this is copy-initialization. In that case, "The
2798 result of the call is then used to direct-initialize the
2799 object that is the destination of the copy-initialization."
2802 We represent this in the conversion sequence with an
2803 rvalue conversion, which means a constructor call. */
2804 if (TREE_CODE (totype) != REFERENCE_TYPE
2805 && !(convflags & LOOKUP_NO_TEMP_BIND))
2807 = build_conv (ck_rvalue, totype, cand->second_conv);
2812 args = build_tree_list (NULL_TREE, build_this (expr));
2814 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2817 tree conversion_path = TREE_PURPOSE (conv_fns);
2819 /* If we are called to convert to a reference type, we are trying to
2820 find an lvalue binding, so don't even consider temporaries. If
2821 we don't find an lvalue binding, the caller will try again to
2822 look for a temporary binding. */
2823 if (TREE_CODE (totype) == REFERENCE_TYPE)
2824 convflags |= LOOKUP_NO_TEMP_BIND;
2826 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2828 tree fn = OVL_CURRENT (fns);
2830 /* [over.match.funcs] For conversion functions, the function
2831 is considered to be a member of the class of the implicit
2832 object argument for the purpose of defining the type of
2833 the implicit object parameter.
2835 So we pass fromtype as CTYPE to add_*_candidate. */
2837 if (TREE_CODE (fn) == TEMPLATE_DECL)
2838 cand = add_template_candidate (&candidates, fn, fromtype,
2841 TYPE_BINFO (fromtype),
2846 cand = add_function_candidate (&candidates, fn, fromtype,
2848 TYPE_BINFO (fromtype),
2855 = implicit_conversion (totype,
2856 TREE_TYPE (TREE_TYPE (cand->fn)),
2858 /*c_cast_p=*/false, convflags);
2860 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2861 copy-initialization. In that case, "The result of the
2862 call is then used to direct-initialize the object that is
2863 the destination of the copy-initialization." [dcl.init]
2865 We represent this in the conversion sequence with an
2866 rvalue conversion, which means a constructor call. But
2867 don't add a second rvalue conversion if there's already
2868 one there. Which there really shouldn't be, but it's
2869 harmless since we'd add it here anyway. */
2870 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
2871 && !(convflags & LOOKUP_NO_TEMP_BIND))
2872 ics = build_conv (ck_rvalue, totype, ics);
2874 cand->second_conv = ics;
2878 else if (candidates->viable == 1 && ics->bad_p)
2884 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2888 cand = tourney (candidates);
2891 if (flags & LOOKUP_COMPLAIN)
2893 error ("conversion from %qT to %qT is ambiguous",
2895 print_z_candidates (candidates);
2898 cand = candidates; /* any one will do */
2899 cand->second_conv = build_ambiguous_conv (totype, expr);
2900 cand->second_conv->user_conv_p = true;
2901 if (!any_strictly_viable (candidates))
2902 cand->second_conv->bad_p = true;
2903 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2904 ambiguous conversion is no worse than another user-defined
2910 /* Build the user conversion sequence. */
2913 (DECL_CONSTRUCTOR_P (cand->fn)
2914 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2915 build_identity_conv (TREE_TYPE (expr), expr));
2918 /* Remember that this was a list-initialization. */
2919 if (flags & LOOKUP_NO_NARROWING)
2920 conv->check_narrowing = true;
2922 /* Combine it with the second conversion sequence. */
2923 cand->second_conv = merge_conversion_sequences (conv,
2926 if (cand->viable == -1)
2927 cand->second_conv->bad_p = true;
2933 build_user_type_conversion (tree totype, tree expr, int flags)
2935 struct z_candidate *cand
2936 = build_user_type_conversion_1 (totype, expr, flags);
2940 if (cand->second_conv->kind == ck_ambig)
2941 return error_mark_node;
2942 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
2943 return convert_from_reference (expr);
2948 /* Do any initial processing on the arguments to a function call. */
2951 resolve_args (tree args)
2954 for (t = args; t; t = TREE_CHAIN (t))
2956 tree arg = TREE_VALUE (t);
2958 if (error_operand_p (arg))
2959 return error_mark_node;
2960 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2962 error ("invalid use of void expression");
2963 return error_mark_node;
2965 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
2966 return error_mark_node;
2971 /* Perform overload resolution on FN, which is called with the ARGS.
2973 Return the candidate function selected by overload resolution, or
2974 NULL if the event that overload resolution failed. In the case
2975 that overload resolution fails, *CANDIDATES will be the set of
2976 candidates considered, and ANY_VIABLE_P will be set to true or
2977 false to indicate whether or not any of the candidates were
2980 The ARGS should already have gone through RESOLVE_ARGS before this
2981 function is called. */
2983 static struct z_candidate *
2984 perform_overload_resolution (tree fn,
2986 struct z_candidate **candidates,
2989 struct z_candidate *cand;
2990 tree explicit_targs = NULL_TREE;
2991 int template_only = 0;
2994 *any_viable_p = true;
2996 /* Check FN and ARGS. */
2997 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2998 || TREE_CODE (fn) == TEMPLATE_DECL
2999 || TREE_CODE (fn) == OVERLOAD
3000 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3001 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
3003 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3005 explicit_targs = TREE_OPERAND (fn, 1);
3006 fn = TREE_OPERAND (fn, 0);
3010 /* Add the various candidate functions. */
3011 add_candidates (fn, args, explicit_targs, template_only,
3012 /*conversion_path=*/NULL_TREE,
3013 /*access_path=*/NULL_TREE,
3017 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3021 cand = tourney (*candidates);
3025 /* Return an expression for a call to FN (a namespace-scope function,
3026 or a static member function) with the ARGS. */
3029 build_new_function_call (tree fn, tree args, bool koenig_p,
3030 tsubst_flags_t complain)
3032 struct z_candidate *candidates, *cand;
3037 args = resolve_args (args);
3038 if (args == error_mark_node)
3039 return error_mark_node;
3041 /* If this function was found without using argument dependent
3042 lookup, then we want to ignore any undeclared friend
3048 fn = remove_hidden_names (fn);
3051 if (complain & tf_error)
3052 error ("no matching function for call to %<%D(%A)%>",
3053 DECL_NAME (OVL_CURRENT (orig_fn)), args);
3054 return error_mark_node;
3058 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3059 p = conversion_obstack_alloc (0);
3061 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
3065 if (complain & tf_error)
3067 if (!any_viable_p && candidates && ! candidates->next)
3068 return cp_build_function_call (candidates->fn, args, complain);
3069 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3070 fn = TREE_OPERAND (fn, 0);
3072 error ("no matching function for call to %<%D(%A)%>",
3073 DECL_NAME (OVL_CURRENT (fn)), args);
3075 error ("call of overloaded %<%D(%A)%> is ambiguous",
3076 DECL_NAME (OVL_CURRENT (fn)), args);
3078 print_z_candidates (candidates);
3080 result = error_mark_node;
3083 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3085 /* Free all the conversions we allocated. */
3086 obstack_free (&conversion_obstack, p);
3091 /* Build a call to a global operator new. FNNAME is the name of the
3092 operator (either "operator new" or "operator new[]") and ARGS are
3093 the arguments provided. *SIZE points to the total number of bytes
3094 required by the allocation, and is updated if that is changed here.
3095 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
3096 function determines that no cookie should be used, after all,
3097 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
3098 set, upon return, to the allocation function called. */
3101 build_operator_new_call (tree fnname, tree args,
3102 tree *size, tree *cookie_size,
3106 struct z_candidate *candidates;
3107 struct z_candidate *cand;
3112 args = tree_cons (NULL_TREE, *size, args);
3113 args = resolve_args (args);
3114 if (args == error_mark_node)
3121 If this lookup fails to find the name, or if the allocated type
3122 is not a class type, the allocation function's name is looked
3123 up in the global scope.
3125 we disregard block-scope declarations of "operator new". */
3126 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
3128 /* Figure out what function is being called. */
3129 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
3131 /* If no suitable function could be found, issue an error message
3136 error ("no matching function for call to %<%D(%A)%>",
3137 DECL_NAME (OVL_CURRENT (fns)), args);
3139 error ("call of overloaded %<%D(%A)%> is ambiguous",
3140 DECL_NAME (OVL_CURRENT (fns)), args);
3142 print_z_candidates (candidates);
3143 return error_mark_node;
3146 /* If a cookie is required, add some extra space. Whether
3147 or not a cookie is required cannot be determined until
3148 after we know which function was called. */
3151 bool use_cookie = true;
3152 if (!abi_version_at_least (2))
3154 tree placement = TREE_CHAIN (args);
3155 /* In G++ 3.2, the check was implemented incorrectly; it
3156 looked at the placement expression, rather than the
3157 type of the function. */
3158 if (placement && !TREE_CHAIN (placement)
3159 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
3167 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3168 /* Skip the size_t parameter. */
3169 arg_types = TREE_CHAIN (arg_types);
3170 /* Check the remaining parameters (if any). */
3172 && TREE_CHAIN (arg_types) == void_list_node
3173 && same_type_p (TREE_VALUE (arg_types),
3177 /* If we need a cookie, adjust the number of bytes allocated. */
3180 /* Update the total size. */
3181 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3182 /* Update the argument list to reflect the adjusted size. */
3183 TREE_VALUE (args) = *size;
3186 *cookie_size = NULL_TREE;
3189 /* Tell our caller which function we decided to call. */
3193 /* Build the CALL_EXPR. */
3194 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3198 build_object_call (tree obj, tree args, tsubst_flags_t complain)
3200 struct z_candidate *candidates = 0, *cand;
3201 tree fns, convs, mem_args = NULL_TREE;
3202 tree type = TREE_TYPE (obj);
3204 tree result = NULL_TREE;
3207 if (TYPE_PTRMEMFUNC_P (type))
3209 if (complain & tf_error)
3210 /* It's no good looking for an overloaded operator() on a
3211 pointer-to-member-function. */
3212 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3213 return error_mark_node;
3216 if (TYPE_BINFO (type))
3218 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3219 if (fns == error_mark_node)
3220 return error_mark_node;
3225 args = resolve_args (args);
3227 if (args == error_mark_node)
3228 return error_mark_node;
3230 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3231 p = conversion_obstack_alloc (0);
3235 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
3236 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
3238 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3240 tree fn = OVL_CURRENT (fns);
3241 if (TREE_CODE (fn) == TEMPLATE_DECL)
3242 add_template_candidate (&candidates, fn, base, NULL_TREE,
3243 mem_args, NULL_TREE,
3246 LOOKUP_NORMAL, DEDUCE_CALL);
3248 add_function_candidate
3249 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3250 TYPE_BINFO (type), LOOKUP_NORMAL);
3254 convs = lookup_conversions (type);
3256 for (; convs; convs = TREE_CHAIN (convs))
3258 tree fns = TREE_VALUE (convs);
3259 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3261 if ((TREE_CODE (totype) == POINTER_TYPE
3262 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3263 || (TREE_CODE (totype) == REFERENCE_TYPE
3264 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3265 || (TREE_CODE (totype) == REFERENCE_TYPE
3266 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3267 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3268 for (; fns; fns = OVL_NEXT (fns))
3270 tree fn = OVL_CURRENT (fns);
3271 if (TREE_CODE (fn) == TEMPLATE_DECL)
3272 add_template_conv_candidate
3273 (&candidates, fn, obj, args, totype,
3274 /*access_path=*/NULL_TREE,
3275 /*conversion_path=*/NULL_TREE);
3277 add_conv_candidate (&candidates, fn, obj, args,
3278 /*conversion_path=*/NULL_TREE,
3279 /*access_path=*/NULL_TREE);
3283 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3286 if (complain & tf_error)
3288 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3289 print_z_candidates (candidates);
3291 result = error_mark_node;
3295 cand = tourney (candidates);
3298 if (complain & tf_error)
3300 error ("call of %<(%T) (%A)%> is ambiguous",
3301 TREE_TYPE (obj), args);
3302 print_z_candidates (candidates);
3304 result = error_mark_node;
3306 /* Since cand->fn will be a type, not a function, for a conversion
3307 function, we must be careful not to unconditionally look at
3309 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3310 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3311 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3314 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
3316 obj = convert_from_reference (obj);
3317 result = cp_build_function_call (obj, args, complain);
3321 /* Free all the conversions we allocated. */
3322 obstack_free (&conversion_obstack, p);
3328 op_error (enum tree_code code, enum tree_code code2,
3329 tree arg1, tree arg2, tree arg3, const char *problem)
3333 if (code == MODIFY_EXPR)
3334 opname = assignment_operator_name_info[code2].name;
3336 opname = operator_name_info[code].name;
3341 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3342 problem, arg1, arg2, arg3);
3345 case POSTINCREMENT_EXPR:
3346 case POSTDECREMENT_EXPR:
3347 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3351 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3356 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3361 error ("%s for %<operator%s%> in %<%E %s %E%>",
3362 problem, opname, arg1, opname, arg2);
3364 error ("%s for %<operator%s%> in %<%s%E%>",
3365 problem, opname, opname, arg1);
3370 /* Return the implicit conversion sequence that could be used to
3371 convert E1 to E2 in [expr.cond]. */
3374 conditional_conversion (tree e1, tree e2)
3376 tree t1 = non_reference (TREE_TYPE (e1));
3377 tree t2 = non_reference (TREE_TYPE (e2));
3383 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3384 implicitly converted (clause _conv_) to the type "reference to
3385 T2", subject to the constraint that in the conversion the
3386 reference must bind directly (_dcl.init.ref_) to E1. */
3387 if (real_lvalue_p (e2))
3389 conv = implicit_conversion (build_reference_type (t2),
3393 LOOKUP_NO_TEMP_BIND);
3400 If E1 and E2 have class type, and the underlying class types are
3401 the same or one is a base class of the other: E1 can be converted
3402 to match E2 if the class of T2 is the same type as, or a base
3403 class of, the class of T1, and the cv-qualification of T2 is the
3404 same cv-qualification as, or a greater cv-qualification than, the
3405 cv-qualification of T1. If the conversion is applied, E1 is
3406 changed to an rvalue of type T2 that still refers to the original
3407 source class object (or the appropriate subobject thereof). */
3408 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3409 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3411 if (good_base && at_least_as_qualified_p (t2, t1))
3413 conv = build_identity_conv (t1, e1);
3414 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3415 TYPE_MAIN_VARIANT (t2)))
3416 conv = build_conv (ck_base, t2, conv);
3418 conv = build_conv (ck_rvalue, t2, conv);
3427 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3428 converted to the type that expression E2 would have if E2 were
3429 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3430 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3434 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3435 arguments to the conditional expression. */
3438 build_conditional_expr (tree arg1, tree arg2, tree arg3,
3439 tsubst_flags_t complain)
3443 tree result = NULL_TREE;
3444 tree result_type = NULL_TREE;
3445 bool lvalue_p = true;
3446 struct z_candidate *candidates = 0;
3447 struct z_candidate *cand;
3450 /* As a G++ extension, the second argument to the conditional can be
3451 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3452 c'.) If the second operand is omitted, make sure it is
3453 calculated only once. */
3456 if (complain & tf_error)
3457 pedwarn (input_location, OPT_pedantic,
3458 "ISO C++ forbids omitting the middle term of a ?: expression");
3460 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3461 if (real_lvalue_p (arg1))
3462 arg2 = arg1 = stabilize_reference (arg1);
3464 arg2 = arg1 = save_expr (arg1);
3469 The first expression is implicitly converted to bool (clause
3471 arg1 = perform_implicit_conversion (boolean_type_node, arg1, complain);
3473 /* If something has already gone wrong, just pass that fact up the
3475 if (error_operand_p (arg1)
3476 || error_operand_p (arg2)
3477 || error_operand_p (arg3))
3478 return error_mark_node;
3482 If either the second or the third operand has type (possibly
3483 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3484 array-to-pointer (_conv.array_), and function-to-pointer
3485 (_conv.func_) standard conversions are performed on the second
3486 and third operands. */
3487 arg2_type = unlowered_expr_type (arg2);
3488 arg3_type = unlowered_expr_type (arg3);
3489 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3491 /* Do the conversions. We don't these for `void' type arguments
3492 since it can't have any effect and since decay_conversion
3493 does not handle that case gracefully. */
3494 if (!VOID_TYPE_P (arg2_type))
3495 arg2 = decay_conversion (arg2);
3496 if (!VOID_TYPE_P (arg3_type))
3497 arg3 = decay_conversion (arg3);
3498 arg2_type = TREE_TYPE (arg2);
3499 arg3_type = TREE_TYPE (arg3);
3503 One of the following shall hold:
3505 --The second or the third operand (but not both) is a
3506 throw-expression (_except.throw_); the result is of the
3507 type of the other and is an rvalue.
3509 --Both the second and the third operands have type void; the
3510 result is of type void and is an rvalue.
3512 We must avoid calling force_rvalue for expressions of type
3513 "void" because it will complain that their value is being
3515 if (TREE_CODE (arg2) == THROW_EXPR
3516 && TREE_CODE (arg3) != THROW_EXPR)
3518 if (!VOID_TYPE_P (arg3_type))
3519 arg3 = force_rvalue (arg3);
3520 arg3_type = TREE_TYPE (arg3);
3521 result_type = arg3_type;
3523 else if (TREE_CODE (arg2) != THROW_EXPR
3524 && TREE_CODE (arg3) == THROW_EXPR)
3526 if (!VOID_TYPE_P (arg2_type))
3527 arg2 = force_rvalue (arg2);
3528 arg2_type = TREE_TYPE (arg2);
3529 result_type = arg2_type;
3531 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3532 result_type = void_type_node;
3535 if (complain & tf_error)
3537 if (VOID_TYPE_P (arg2_type))
3538 error ("second operand to the conditional operator "
3539 "is of type %<void%>, "
3540 "but the third operand is neither a throw-expression "
3541 "nor of type %<void%>");
3543 error ("third operand to the conditional operator "
3544 "is of type %<void%>, "
3545 "but the second operand is neither a throw-expression "
3546 "nor of type %<void%>");
3548 return error_mark_node;
3552 goto valid_operands;
3556 Otherwise, if the second and third operand have different types,
3557 and either has (possibly cv-qualified) class type, an attempt is
3558 made to convert each of those operands to the type of the other. */
3559 else if (!same_type_p (arg2_type, arg3_type)
3560 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3565 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3566 p = conversion_obstack_alloc (0);
3568 conv2 = conditional_conversion (arg2, arg3);
3569 conv3 = conditional_conversion (arg3, arg2);
3573 If both can be converted, or one can be converted but the
3574 conversion is ambiguous, the program is ill-formed. If
3575 neither can be converted, the operands are left unchanged and
3576 further checking is performed as described below. If exactly
3577 one conversion is possible, that conversion is applied to the
3578 chosen operand and the converted operand is used in place of
3579 the original operand for the remainder of this section. */
3580 if ((conv2 && !conv2->bad_p
3581 && conv3 && !conv3->bad_p)
3582 || (conv2 && conv2->kind == ck_ambig)
3583 || (conv3 && conv3->kind == ck_ambig))
3585 error ("operands to ?: have different types %qT and %qT",
3586 arg2_type, arg3_type);
3587 result = error_mark_node;
3589 else if (conv2 && (!conv2->bad_p || !conv3))
3591 arg2 = convert_like (conv2, arg2, complain);
3592 arg2 = convert_from_reference (arg2);
3593 arg2_type = TREE_TYPE (arg2);
3594 /* Even if CONV2 is a valid conversion, the result of the
3595 conversion may be invalid. For example, if ARG3 has type
3596 "volatile X", and X does not have a copy constructor
3597 accepting a "volatile X&", then even if ARG2 can be
3598 converted to X, the conversion will fail. */
3599 if (error_operand_p (arg2))
3600 result = error_mark_node;
3602 else if (conv3 && (!conv3->bad_p || !conv2))
3604 arg3 = convert_like (conv3, arg3, complain);
3605 arg3 = convert_from_reference (arg3);
3606 arg3_type = TREE_TYPE (arg3);
3607 if (error_operand_p (arg3))
3608 result = error_mark_node;
3611 /* Free all the conversions we allocated. */
3612 obstack_free (&conversion_obstack, p);
3617 /* If, after the conversion, both operands have class type,
3618 treat the cv-qualification of both operands as if it were the
3619 union of the cv-qualification of the operands.
3621 The standard is not clear about what to do in this
3622 circumstance. For example, if the first operand has type
3623 "const X" and the second operand has a user-defined
3624 conversion to "volatile X", what is the type of the second
3625 operand after this step? Making it be "const X" (matching
3626 the first operand) seems wrong, as that discards the
3627 qualification without actually performing a copy. Leaving it
3628 as "volatile X" seems wrong as that will result in the
3629 conditional expression failing altogether, even though,
3630 according to this step, the one operand could be converted to
3631 the type of the other. */
3632 if ((conv2 || conv3)
3633 && CLASS_TYPE_P (arg2_type)
3634 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3635 arg2_type = arg3_type =
3636 cp_build_qualified_type (arg2_type,
3637 TYPE_QUALS (arg2_type)
3638 | TYPE_QUALS (arg3_type));
3643 If the second and third operands are lvalues and have the same
3644 type, the result is of that type and is an lvalue. */
3645 if (real_lvalue_p (arg2)
3646 && real_lvalue_p (arg3)
3647 && same_type_p (arg2_type, arg3_type))
3649 result_type = arg2_type;
3650 goto valid_operands;
3655 Otherwise, the result is an rvalue. If the second and third
3656 operand do not have the same type, and either has (possibly
3657 cv-qualified) class type, overload resolution is used to
3658 determine the conversions (if any) to be applied to the operands
3659 (_over.match.oper_, _over.built_). */
3661 if (!same_type_p (arg2_type, arg3_type)
3662 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3668 /* Rearrange the arguments so that add_builtin_candidate only has
3669 to know about two args. In build_builtin_candidates, the
3670 arguments are unscrambled. */
3674 add_builtin_candidates (&candidates,
3677 ansi_opname (COND_EXPR),
3683 If the overload resolution fails, the program is
3685 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3688 if (complain & tf_error)
3690 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3691 print_z_candidates (candidates);
3693 return error_mark_node;
3695 cand = tourney (candidates);
3698 if (complain & tf_error)
3700 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3701 print_z_candidates (candidates);
3703 return error_mark_node;
3708 Otherwise, the conversions thus determined are applied, and
3709 the converted operands are used in place of the original
3710 operands for the remainder of this section. */
3711 conv = cand->convs[0];
3712 arg1 = convert_like (conv, arg1, complain);
3713 conv = cand->convs[1];
3714 arg2 = convert_like (conv, arg2, complain);
3715 conv = cand->convs[2];
3716 arg3 = convert_like (conv, arg3, complain);
3721 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3722 and function-to-pointer (_conv.func_) standard conversions are
3723 performed on the second and third operands.
3725 We need to force the lvalue-to-rvalue conversion here for class types,
3726 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3727 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3730 arg2 = force_rvalue (arg2);
3731 if (!CLASS_TYPE_P (arg2_type))
3732 arg2_type = TREE_TYPE (arg2);
3734 arg3 = force_rvalue (arg3);
3735 if (!CLASS_TYPE_P (arg2_type))
3736 arg3_type = TREE_TYPE (arg3);
3738 if (arg2 == error_mark_node || arg3 == error_mark_node)
3739 return error_mark_node;
3743 After those conversions, one of the following shall hold:
3745 --The second and third operands have the same type; the result is of
3747 if (same_type_p (arg2_type, arg3_type))
3748 result_type = arg2_type;
3751 --The second and third operands have arithmetic or enumeration
3752 type; the usual arithmetic conversions are performed to bring
3753 them to a common type, and the result is of that type. */
3754 else if ((ARITHMETIC_TYPE_P (arg2_type)
3755 || UNSCOPED_ENUM_P (arg2_type))
3756 && (ARITHMETIC_TYPE_P (arg3_type)
3757 || UNSCOPED_ENUM_P (arg3_type)))
3759 /* In this case, there is always a common type. */
3760 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3763 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3764 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3766 if (complain & tf_warning)
3768 "enumeral mismatch in conditional expression: %qT vs %qT",
3769 arg2_type, arg3_type);
3771 else if (extra_warnings
3772 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3773 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3774 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3775 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3777 if (complain & tf_warning)
3779 "enumeral and non-enumeral type in conditional expression");
3782 arg2 = perform_implicit_conversion (result_type, arg2, complain);
3783 arg3 = perform_implicit_conversion (result_type, arg3, complain);
3787 --The second and third operands have pointer type, or one has
3788 pointer type and the other is a null pointer constant; pointer
3789 conversions (_conv.ptr_) and qualification conversions
3790 (_conv.qual_) are performed to bring them to their composite
3791 pointer type (_expr.rel_). The result is of the composite
3794 --The second and third operands have pointer to member type, or
3795 one has pointer to member type and the other is a null pointer
3796 constant; pointer to member conversions (_conv.mem_) and
3797 qualification conversions (_conv.qual_) are performed to bring
3798 them to a common type, whose cv-qualification shall match the
3799 cv-qualification of either the second or the third operand.
3800 The result is of the common type. */
3801 else if ((null_ptr_cst_p (arg2)
3802 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3803 || (null_ptr_cst_p (arg3)
3804 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3805 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3806 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3807 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3809 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3810 arg3, "conditional expression",
3812 if (result_type == error_mark_node)
3813 return error_mark_node;
3814 arg2 = perform_implicit_conversion (result_type, arg2, complain);
3815 arg3 = perform_implicit_conversion (result_type, arg3, complain);
3820 if (complain & tf_error)
3821 error ("operands to ?: have different types %qT and %qT",
3822 arg2_type, arg3_type);
3823 return error_mark_node;
3827 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3829 /* We can't use result_type below, as fold might have returned a
3834 /* Expand both sides into the same slot, hopefully the target of
3835 the ?: expression. We used to check for TARGET_EXPRs here,
3836 but now we sometimes wrap them in NOP_EXPRs so the test would
3838 if (CLASS_TYPE_P (TREE_TYPE (result)))
3839 result = get_target_expr (result);
3840 /* If this expression is an rvalue, but might be mistaken for an
3841 lvalue, we must add a NON_LVALUE_EXPR. */
3842 result = rvalue (result);
3848 /* OPERAND is an operand to an expression. Perform necessary steps
3849 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3853 prep_operand (tree operand)
3857 if (CLASS_TYPE_P (TREE_TYPE (operand))
3858 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3859 /* Make sure the template type is instantiated now. */
3860 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3866 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3867 OVERLOAD) to the CANDIDATES, returning an updated list of
3868 CANDIDATES. The ARGS are the arguments provided to the call,
3869 without any implicit object parameter. The EXPLICIT_TARGS are
3870 explicit template arguments provided. TEMPLATE_ONLY is true if
3871 only template functions should be considered. CONVERSION_PATH,
3872 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3875 add_candidates (tree fns, tree args,
3876 tree explicit_targs, bool template_only,
3877 tree conversion_path, tree access_path,
3879 struct z_candidate **candidates)
3882 tree non_static_args;
3884 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3885 /* Delay creating the implicit this parameter until it is needed. */
3886 non_static_args = NULL_TREE;
3893 fn = OVL_CURRENT (fns);
3894 /* Figure out which set of arguments to use. */
3895 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3897 /* If this function is a non-static member, prepend the implicit
3898 object parameter. */
3899 if (!non_static_args)
3900 non_static_args = tree_cons (NULL_TREE,
3901 build_this (TREE_VALUE (args)),
3903 fn_args = non_static_args;
3906 /* Otherwise, just use the list of arguments provided. */
3909 if (TREE_CODE (fn) == TEMPLATE_DECL)
3910 add_template_candidate (candidates,
3920 else if (!template_only)
3921 add_function_candidate (candidates,
3928 fns = OVL_NEXT (fns);
3933 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3934 bool *overloaded_p, tsubst_flags_t complain)
3936 struct z_candidate *candidates = 0, *cand;
3937 tree arglist, fnname;
3939 tree result = NULL_TREE;
3940 bool result_valid_p = false;
3941 enum tree_code code2 = NOP_EXPR;
3946 bool expl_eq_arg1 = false;
3948 if (error_operand_p (arg1)
3949 || error_operand_p (arg2)
3950 || error_operand_p (arg3))
3951 return error_mark_node;
3953 if (code == MODIFY_EXPR)
3955 code2 = TREE_CODE (arg3);
3957 fnname = ansi_assopname (code2);
3960 fnname = ansi_opname (code);
3962 arg1 = prep_operand (arg1);
3968 case VEC_DELETE_EXPR:
3970 /* Use build_op_new_call and build_op_delete_call instead. */
3974 return build_object_call (arg1, arg2, complain);
3976 case TRUTH_ORIF_EXPR:
3977 case TRUTH_ANDIF_EXPR:
3978 case TRUTH_AND_EXPR:
3980 if (COMPARISON_CLASS_P (arg1))
3981 expl_eq_arg1 = true;
3986 arg2 = prep_operand (arg2);
3987 arg3 = prep_operand (arg3);
3989 if (code == COND_EXPR)
3991 if (arg2 == NULL_TREE
3992 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3993 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3994 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3995 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3998 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3999 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4002 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4003 arg2 = integer_zero_node;
4005 arglist = NULL_TREE;
4007 arglist = tree_cons (NULL_TREE, arg3, arglist);
4009 arglist = tree_cons (NULL_TREE, arg2, arglist);
4010 arglist = tree_cons (NULL_TREE, arg1, arglist);
4012 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4013 p = conversion_obstack_alloc (0);
4015 /* Add namespace-scope operators to the list of functions to
4017 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4018 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
4019 flags, &candidates);
4020 /* Add class-member operators to the candidate set. */
4021 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4025 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4026 if (fns == error_mark_node)
4028 result = error_mark_node;
4029 goto user_defined_result_ready;
4032 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
4034 BASELINK_BINFO (fns),
4035 TYPE_BINFO (TREE_TYPE (arg1)),
4036 flags, &candidates);
4039 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
4040 to know about two args; a builtin candidate will always have a first
4041 parameter of type bool. We'll handle that in
4042 build_builtin_candidate. */
4043 if (code == COND_EXPR)
4053 args[2] = NULL_TREE;
4056 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4062 /* For these, the built-in candidates set is empty
4063 [over.match.oper]/3. We don't want non-strict matches
4064 because exact matches are always possible with built-in
4065 operators. The built-in candidate set for COMPONENT_REF
4066 would be empty too, but since there are no such built-in
4067 operators, we accept non-strict matches for them. */
4072 strict_p = pedantic;
4076 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4081 case POSTINCREMENT_EXPR:
4082 case POSTDECREMENT_EXPR:
4083 /* Don't try anything fancy if we're not allowed to produce
4085 if (!(complain & tf_error))
4086 return error_mark_node;
4088 /* Look for an `operator++ (int)'. If they didn't have
4089 one, then we fall back to the old way of doing things. */
4090 if (flags & LOOKUP_COMPLAIN)
4091 permerror (input_location, "no %<%D(int)%> declared for postfix %qs, "
4092 "trying prefix operator instead",
4094 operator_name_info[code].name);
4095 if (code == POSTINCREMENT_EXPR)
4096 code = PREINCREMENT_EXPR;
4098 code = PREDECREMENT_EXPR;
4099 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
4100 overloaded_p, complain);
4103 /* The caller will deal with these. */
4108 result_valid_p = true;
4112 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4114 /* If one of the arguments of the operator represents
4115 an invalid use of member function pointer, try to report
4116 a meaningful error ... */
4117 if (invalid_nonstatic_memfn_p (arg1, tf_error)
4118 || invalid_nonstatic_memfn_p (arg2, tf_error)
4119 || invalid_nonstatic_memfn_p (arg3, tf_error))
4120 /* We displayed the error message. */;
4123 /* ... Otherwise, report the more generic
4124 "no matching operator found" error */
4125 op_error (code, code2, arg1, arg2, arg3, "no match");
4126 print_z_candidates (candidates);
4129 result = error_mark_node;
4135 cand = tourney (candidates);
4138 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4140 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
4141 print_z_candidates (candidates);
4143 result = error_mark_node;
4145 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4148 *overloaded_p = true;
4150 if (resolve_args (arglist) == error_mark_node)
4151 result = error_mark_node;
4153 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4157 /* Give any warnings we noticed during overload resolution. */
4158 if (cand->warnings && (complain & tf_warning))
4160 struct candidate_warning *w;
4161 for (w = cand->warnings; w; w = w->next)
4162 joust (cand, w->loser, 1);
4165 /* Check for comparison of different enum types. */
4174 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
4175 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
4176 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
4177 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
4178 && (complain & tf_warning))
4180 warning (OPT_Wenum_compare,
4181 "comparison between %q#T and %q#T",
4182 TREE_TYPE (arg1), TREE_TYPE (arg2));
4189 /* We need to strip any leading REF_BIND so that bitfields
4190 don't cause errors. This should not remove any important
4191 conversions, because builtins don't apply to class
4192 objects directly. */
4193 conv = cand->convs[0];
4194 if (conv->kind == ck_ref_bind)
4195 conv = conv->u.next;
4196 arg1 = convert_like (conv, arg1, complain);
4199 conv = cand->convs[1];
4200 if (conv->kind == ck_ref_bind)
4201 conv = conv->u.next;
4202 arg2 = convert_like (conv, arg2, complain);
4206 conv = cand->convs[2];
4207 if (conv->kind == ck_ref_bind)
4208 conv = conv->u.next;
4209 arg3 = convert_like (conv, arg3, complain);
4214 if (complain & tf_warning)
4215 warn_logical_operator (code, arg1, arg2);
4216 expl_eq_arg1 = true;
4221 user_defined_result_ready:
4223 /* Free all the conversions we allocated. */
4224 obstack_free (&conversion_obstack, p);
4226 if (result || result_valid_p)
4233 return cp_build_modify_expr (arg1, code2, arg2, complain);
4236 return cp_build_indirect_ref (arg1, "unary *", complain);
4238 case TRUTH_ANDIF_EXPR:
4239 case TRUTH_ORIF_EXPR:
4240 case TRUTH_AND_EXPR:
4243 warn_logical_operator (code, arg1, arg2);
4247 case TRUNC_DIV_EXPR:
4258 case TRUNC_MOD_EXPR:
4262 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
4264 case UNARY_PLUS_EXPR:
4267 case TRUTH_NOT_EXPR:
4268 case PREINCREMENT_EXPR:
4269 case POSTINCREMENT_EXPR:
4270 case PREDECREMENT_EXPR:
4271 case POSTDECREMENT_EXPR:
4274 return cp_build_unary_op (code, arg1, candidates != 0, complain);
4277 return build_array_ref (arg1, arg2, input_location);
4280 return build_conditional_expr (arg1, arg2, arg3, complain);
4283 return build_m_component_ref (cp_build_indirect_ref (arg1, NULL,
4287 /* The caller will deal with these. */
4299 /* Build a call to operator delete. This has to be handled very specially,
4300 because the restrictions on what signatures match are different from all
4301 other call instances. For a normal delete, only a delete taking (void *)
4302 or (void *, size_t) is accepted. For a placement delete, only an exact
4303 match with the placement new is accepted.
4305 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4306 ADDR is the pointer to be deleted.
4307 SIZE is the size of the memory block to be deleted.
4308 GLOBAL_P is true if the delete-expression should not consider
4309 class-specific delete operators.
4310 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4312 If this call to "operator delete" is being generated as part to
4313 deallocate memory allocated via a new-expression (as per [expr.new]
4314 which requires that if the initialization throws an exception then
4315 we call a deallocation function), then ALLOC_FN is the allocation
4319 build_op_delete_call (enum tree_code code, tree addr, tree size,
4320 bool global_p, tree placement,
4323 tree fn = NULL_TREE;
4324 tree fns, fnname, argtypes, type;
4327 if (addr == error_mark_node)
4328 return error_mark_node;
4330 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4332 fnname = ansi_opname (code);
4334 if (CLASS_TYPE_P (type)
4335 && COMPLETE_TYPE_P (complete_type (type))
4339 If the result of the lookup is ambiguous or inaccessible, or if
4340 the lookup selects a placement deallocation function, the
4341 program is ill-formed.
4343 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4345 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4346 if (fns == error_mark_node)
4347 return error_mark_node;
4352 if (fns == NULL_TREE)
4353 fns = lookup_name_nonclass (fnname);
4355 /* Strip const and volatile from addr. */
4356 addr = cp_convert (ptr_type_node, addr);
4360 /* Get the parameter types for the allocation function that is
4362 gcc_assert (alloc_fn != NULL_TREE);
4363 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4367 /* First try it without the size argument. */
4368 argtypes = void_list_node;
4371 /* We make two tries at finding a matching `operator delete'. On
4372 the first pass, we look for a one-operator (or placement)
4373 operator delete. If we're not doing placement delete, then on
4374 the second pass we look for a two-argument delete. */
4375 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4377 /* Go through the `operator delete' functions looking for one
4378 with a matching type. */
4379 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4385 /* The first argument must be "void *". */
4386 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4387 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4390 /* On the first pass, check the rest of the arguments. */
4396 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4404 /* On the second pass, look for a function with exactly two
4405 arguments: "void *" and "size_t". */
4407 /* For "operator delete(void *, ...)" there will be
4408 no second argument, but we will not get an exact
4411 && same_type_p (TREE_VALUE (t), size_type_node)
4412 && TREE_CHAIN (t) == void_list_node)
4416 /* If we found a match, we're done. */
4421 /* If we have a matching function, call it. */
4424 /* Make sure we have the actual function, and not an
4426 fn = OVL_CURRENT (fn);
4428 /* If the FN is a member function, make sure that it is
4430 if (DECL_CLASS_SCOPE_P (fn))
4431 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4435 /* The placement args might not be suitable for overload
4436 resolution at this point, so build the call directly. */
4437 int nargs = call_expr_nargs (placement);
4438 tree *argarray = (tree *) alloca (nargs * sizeof (tree));
4441 for (i = 1; i < nargs; i++)
4442 argarray[i] = CALL_EXPR_ARG (placement, i);
4444 return build_cxx_call (fn, nargs, argarray);
4450 args = tree_cons (NULL_TREE, addr, NULL_TREE);
4452 args = tree_cons (NULL_TREE, addr,
4453 build_tree_list (NULL_TREE, size));
4454 return cp_build_function_call (fn, args, tf_warning_or_error);
4460 If no unambiguous matching deallocation function can be found,
4461 propagating the exception does not cause the object's memory to
4466 warning (0, "no corresponding deallocation function for %qD",
4471 error ("no suitable %<operator %s%> for %qT",
4472 operator_name_info[(int)code].name, type);
4473 return error_mark_node;
4476 /* If the current scope isn't allowed to access DECL along
4477 BASETYPE_PATH, give an error. The most derived class in
4478 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4479 the declaration to use in the error diagnostic. */
4482 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4484 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4486 if (!accessible_p (basetype_path, decl, true))
4488 if (TREE_PRIVATE (decl))
4489 error ("%q+#D is private", diag_decl);
4490 else if (TREE_PROTECTED (decl))
4491 error ("%q+#D is protected", diag_decl);
4493 error ("%q+#D is inaccessible", diag_decl);
4494 error ("within this context");
4501 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4502 bitwise or of LOOKUP_* values. If any errors are warnings are
4503 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4504 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4508 build_temp (tree expr, tree type, int flags,
4509 diagnostic_t *diagnostic_kind)
4513 savew = warningcount, savee = errorcount;
4514 expr = build_special_member_call (NULL_TREE,
4515 complete_ctor_identifier,
4516 build_tree_list (NULL_TREE, expr),
4517 type, flags, tf_warning_or_error);
4518 if (warningcount > savew)
4519 *diagnostic_kind = DK_WARNING;
4520 else if (errorcount > savee)
4521 *diagnostic_kind = DK_ERROR;
4523 *diagnostic_kind = 0;
4527 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4528 EXPR is implicitly converted to type TOTYPE.
4529 FN and ARGNUM are used for diagnostics. */
4532 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
4534 tree t = non_reference (totype);
4536 /* Issue warnings about peculiar, but valid, uses of NULL. */
4537 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
4540 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4543 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4546 /* Issue warnings if "false" is converted to a NULL pointer */
4547 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
4548 warning (OPT_Wconversion,
4549 "converting %<false%> to pointer type for argument %P of %qD",
4553 /* Perform the conversions in CONVS on the expression EXPR. FN and
4554 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4555 indicates the `this' argument of a method. INNER is nonzero when
4556 being called to continue a conversion chain. It is negative when a
4557 reference binding will be applied, positive otherwise. If
4558 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4559 conversions will be emitted if appropriate. If C_CAST_P is true,
4560 this conversion is coming from a C-style cast; in that case,
4561 conversions to inaccessible bases are permitted. */
4564 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4565 int inner, bool issue_conversion_warnings,
4566 bool c_cast_p, tsubst_flags_t complain)
4568 tree totype = convs->type;
4569 diagnostic_t diag_kind;
4573 && convs->kind != ck_user
4574 && convs->kind != ck_list
4575 && convs->kind != ck_ambig
4576 && convs->kind != ck_ref_bind
4577 && convs->kind != ck_rvalue
4578 && convs->kind != ck_base)
4580 conversion *t = convs;
4582 /* Give a helpful error if this is bad because of excess braces. */
4583 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
4584 && SCALAR_TYPE_P (totype)
4585 && CONSTRUCTOR_NELTS (expr) > 0
4586 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
4587 permerror (input_location, "too many braces around initializer for %qT", totype);
4589 for (; t; t = convs->u.next)
4591 if (t->kind == ck_user || !t->bad_p)
4593 expr = convert_like_real (t, expr, fn, argnum, 1,
4594 /*issue_conversion_warnings=*/false,
4599 else if (t->kind == ck_ambig)
4600 return convert_like_real (t, expr, fn, argnum, 1,
4601 /*issue_conversion_warnings=*/false,
4604 else if (t->kind == ck_identity)
4607 if (complain & tf_error)
4609 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4611 permerror (input_location, " initializing argument %P of %qD", argnum, fn);
4614 return error_mark_node;
4616 return cp_convert (totype, expr);
4619 if (issue_conversion_warnings && (complain & tf_warning))
4620 conversion_null_warnings (totype, expr, fn, argnum);
4622 switch (convs->kind)
4626 struct z_candidate *cand = convs->cand;
4627 tree convfn = cand->fn;
4630 /* When converting from an init list we consider explicit
4631 constructors, but actually trying to call one is an error. */
4632 if (DECL_NONCONVERTING_P (convfn))
4634 if (complain & tf_error)
4635 error ("converting to %qT from initializer list would use "
4636 "explicit constructor %qD", totype, convfn);
4638 return error_mark_node;
4641 /* Set user_conv_p on the argument conversions, so rvalue/base
4642 handling knows not to allow any more UDCs. */
4643 for (i = 0; i < cand->num_convs; ++i)
4644 cand->convs[i]->user_conv_p = true;
4646 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
4648 /* If this is a constructor or a function returning an aggr type,
4649 we need to build up a TARGET_EXPR. */
4650 if (DECL_CONSTRUCTOR_P (convfn))
4652 expr = build_cplus_new (totype, expr);
4654 /* Remember that this was list-initialization. */
4655 if (convs->check_narrowing)
4656 TARGET_EXPR_LIST_INIT_P (expr) = true;
4662 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
4664 int nelts = CONSTRUCTOR_NELTS (expr);
4666 expr = integer_zero_node;
4667 else if (nelts == 1)
4668 expr = CONSTRUCTOR_ELT (expr, 0)->value;
4673 if (type_unknown_p (expr))
4674 expr = instantiate_type (totype, expr, complain);
4675 /* Convert a constant to its underlying value, unless we are
4676 about to bind it to a reference, in which case we need to
4677 leave it as an lvalue. */
4680 expr = decl_constant_value (expr);
4681 if (expr == null_node && INTEGRAL_TYPE_P (totype))
4682 /* If __null has been converted to an integer type, we do not
4683 want to warn about uses of EXPR as an integer, rather than
4685 expr = build_int_cst (totype, 0);
4689 /* Call build_user_type_conversion again for the error. */
4690 return build_user_type_conversion
4691 (totype, convs->u.expr, LOOKUP_NORMAL);
4695 /* Conversion to std::initializer_list<T>. */
4696 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
4697 tree new_ctor = build_constructor (init_list_type_node, NULL);
4698 unsigned len = CONSTRUCTOR_NELTS (expr);
4699 tree array, parms, val;
4702 /* Convert all the elements. */
4703 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
4705 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
4706 1, false, false, complain);
4707 if (sub == error_mark_node)
4709 check_narrowing (TREE_TYPE (sub), val);
4710 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
4712 /* Build up the array. */
4713 elttype = cp_build_qualified_type
4714 (elttype, TYPE_QUALS (elttype) | TYPE_QUAL_CONST);
4715 array = build_array_of_n_type (elttype, len);
4716 array = finish_compound_literal (array, new_ctor);
4718 parms = build_tree_list (NULL_TREE, size_int (len));
4719 parms = tree_cons (NULL_TREE, decay_conversion (array), parms);
4720 /* Call the private constructor. */
4721 push_deferring_access_checks (dk_no_check);
4722 new_ctor = build_special_member_call
4723 (NULL_TREE, complete_ctor_identifier, parms, totype, 0, complain);
4724 pop_deferring_access_checks ();
4725 return build_cplus_new (totype, new_ctor);
4729 return get_target_expr (digest_init (totype, expr));
4735 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4736 convs->kind == ck_ref_bind ? -1 : 1,
4737 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
4740 if (expr == error_mark_node)
4741 return error_mark_node;
4743 switch (convs->kind)
4746 expr = decay_conversion (expr);
4747 if (! MAYBE_CLASS_TYPE_P (totype))
4749 /* Else fall through. */
4751 if (convs->kind == ck_base && !convs->need_temporary_p)
4753 /* We are going to bind a reference directly to a base-class
4754 subobject of EXPR. */
4755 /* Build an expression for `*((base*) &expr)'. */
4756 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
4757 expr = convert_to_base (expr, build_pointer_type (totype),
4758 !c_cast_p, /*nonnull=*/true);
4759 expr = cp_build_indirect_ref (expr, "implicit conversion", complain);
4763 /* Copy-initialization where the cv-unqualified version of the source
4764 type is the same class as, or a derived class of, the class of the
4765 destination [is treated as direct-initialization]. [dcl.init] */
4766 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
4767 if (convs->user_conv_p)
4768 /* This conversion is being done in the context of a user-defined
4769 conversion (i.e. the second step of copy-initialization), so
4770 don't allow any more. */
4771 flags |= LOOKUP_NO_CONVERSION;
4772 expr = build_temp (expr, totype, flags, &diag_kind);
4773 if (diag_kind && fn)
4775 if ((complain & tf_error))
4776 emit_diagnostic (diag_kind, input_location, 0,
4777 " initializing argument %P of %qD", argnum, fn);
4778 else if (diag_kind == DK_ERROR)
4779 return error_mark_node;
4781 return build_cplus_new (totype, expr);
4785 tree ref_type = totype;
4787 /* If necessary, create a temporary.
4789 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4790 that need temporaries, even when their types are reference
4791 compatible with the type of reference being bound, so the
4792 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
4794 if (convs->need_temporary_p
4795 || TREE_CODE (expr) == CONSTRUCTOR
4796 || TREE_CODE (expr) == VA_ARG_EXPR)
4798 tree type = convs->u.next->type;
4799 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4801 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))
4802 && !TYPE_REF_IS_RVALUE (ref_type))
4804 if (complain & tf_error)
4806 /* If the reference is volatile or non-const, we
4807 cannot create a temporary. */
4808 if (lvalue & clk_bitfield)
4809 error ("cannot bind bitfield %qE to %qT",
4811 else if (lvalue & clk_packed)
4812 error ("cannot bind packed field %qE to %qT",
4815 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4817 return error_mark_node;
4819 /* If the source is a packed field, and we must use a copy
4820 constructor, then building the target expr will require
4821 binding the field to the reference parameter to the
4822 copy constructor, and we'll end up with an infinite
4823 loop. If we can use a bitwise copy, then we'll be
4825 if ((lvalue & clk_packed)
4826 && CLASS_TYPE_P (type)
4827 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4829 if (complain & tf_error)
4830 error ("cannot bind packed field %qE to %qT",
4832 return error_mark_node;
4834 if (lvalue & clk_bitfield)
4836 expr = convert_bitfield_to_declared_type (expr);
4837 expr = fold_convert (type, expr);
4839 expr = build_target_expr_with_type (expr, type);
4842 /* Take the address of the thing to which we will bind the
4844 expr = cp_build_unary_op (ADDR_EXPR, expr, 1, complain);
4845 if (expr == error_mark_node)
4846 return error_mark_node;
4848 /* Convert it to a pointer to the type referred to by the
4849 reference. This will adjust the pointer if a derived to
4850 base conversion is being performed. */
4851 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4853 /* Convert the pointer to the desired reference type. */
4854 return build_nop (ref_type, expr);
4858 return decay_conversion (expr);
4861 /* Warn about deprecated conversion if appropriate. */
4862 string_conv_p (totype, expr, 1);
4867 expr = convert_to_base (expr, totype, !c_cast_p,
4869 return build_nop (totype, expr);
4872 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4879 if (convs->check_narrowing)
4880 check_narrowing (totype, expr);
4882 if (issue_conversion_warnings && (complain & tf_warning))
4883 expr = convert_and_check (totype, expr);
4885 expr = convert (totype, expr);
4890 /* Build a call to __builtin_trap. */
4893 call_builtin_trap (void)
4895 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4897 gcc_assert (fn != NULL);
4898 fn = build_call_n (fn, 0);
4902 /* ARG is being passed to a varargs function. Perform any conversions
4903 required. Return the converted value. */
4906 convert_arg_to_ellipsis (tree arg)
4910 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4911 standard conversions are performed. */
4912 arg = decay_conversion (arg);
4915 If the argument has integral or enumeration type that is subject
4916 to the integral promotions (_conv.prom_), or a floating point
4917 type that is subject to the floating point promotion
4918 (_conv.fpprom_), the value of the argument is converted to the
4919 promoted type before the call. */
4920 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4921 && (TYPE_PRECISION (TREE_TYPE (arg))
4922 < TYPE_PRECISION (double_type_node)))
4923 arg = convert_to_real (double_type_node, arg);
4924 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4925 arg = perform_integral_promotions (arg);
4927 arg = require_complete_type (arg);
4929 if (arg != error_mark_node
4930 && !pod_type_p (TREE_TYPE (arg)))
4932 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4933 here and do a bitwise copy, but now cp_expr_size will abort if we
4935 If the call appears in the context of a sizeof expression,
4936 there is no need to emit a warning, since the expression won't be
4937 evaluated. We keep the builtin_trap just as a safety check. */
4938 if (!skip_evaluation)
4939 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4940 "call will abort at runtime", TREE_TYPE (arg));
4941 arg = call_builtin_trap ();
4942 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4949 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4952 build_x_va_arg (tree expr, tree type)
4954 if (processing_template_decl)
4955 return build_min (VA_ARG_EXPR, type, expr);
4957 type = complete_type_or_else (type, NULL_TREE);
4959 if (expr == error_mark_node || !type)
4960 return error_mark_node;
4962 if (! pod_type_p (type))
4964 /* Remove reference types so we don't ICE later on. */
4965 tree type1 = non_reference (type);
4966 /* Undefined behavior [expr.call] 5.2.2/7. */
4967 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4968 "call will abort at runtime", type);
4969 expr = convert (build_pointer_type (type1), null_node);
4970 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4971 call_builtin_trap (), expr);
4972 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
4976 return build_va_arg (expr, type);
4979 /* TYPE has been given to va_arg. Apply the default conversions which
4980 would have happened when passed via ellipsis. Return the promoted
4981 type, or the passed type if there is no change. */
4984 cxx_type_promotes_to (tree type)
4988 /* Perform the array-to-pointer and function-to-pointer
4990 type = type_decays_to (type);
4992 promote = type_promotes_to (type);
4993 if (same_type_p (type, promote))
4999 /* ARG is a default argument expression being passed to a parameter of
5000 the indicated TYPE, which is a parameter to FN. Do any required
5001 conversions. Return the converted value. */
5003 static GTY(()) VEC(tree,gc) *default_arg_context;
5006 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
5011 /* If the ARG is an unparsed default argument expression, the
5012 conversion cannot be performed. */
5013 if (TREE_CODE (arg) == DEFAULT_ARG)
5015 error ("the default argument for parameter %d of %qD has "
5016 "not yet been parsed",
5018 return error_mark_node;
5021 /* Detect recursion. */
5022 for (i = 0; VEC_iterate (tree, default_arg_context, i, t); ++i)
5025 error ("recursive evaluation of default argument for %q#D", fn);
5026 return error_mark_node;
5028 VEC_safe_push (tree, gc, default_arg_context, fn);
5030 if (fn && DECL_TEMPLATE_INFO (fn))
5031 arg = tsubst_default_argument (fn, type, arg);
5037 The names in the expression are bound, and the semantic
5038 constraints are checked, at the point where the default
5039 expressions appears.
5041 we must not perform access checks here. */
5042 push_deferring_access_checks (dk_no_check);
5043 arg = break_out_target_exprs (arg);
5044 if (TREE_CODE (arg) == CONSTRUCTOR)
5046 arg = digest_init (type, arg);
5047 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
5048 "default argument", fn, parmnum,
5049 tf_warning_or_error);
5053 /* We must make a copy of ARG, in case subsequent processing
5054 alters any part of it. For example, during gimplification a
5055 cast of the form (T) &X::f (where "f" is a member function)
5056 will lead to replacing the PTRMEM_CST for &X::f with a
5057 VAR_DECL. We can avoid the copy for constants, since they
5058 are never modified in place. */
5059 if (!CONSTANT_CLASS_P (arg))
5060 arg = unshare_expr (arg);
5061 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
5062 "default argument", fn, parmnum,
5063 tf_warning_or_error);
5064 arg = convert_for_arg_passing (type, arg);
5066 pop_deferring_access_checks();
5068 VEC_pop (tree, default_arg_context);
5073 /* Returns the type which will really be used for passing an argument of
5077 type_passed_as (tree type)
5079 /* Pass classes with copy ctors by invisible reference. */
5080 if (TREE_ADDRESSABLE (type))
5082 type = build_reference_type (type);
5083 /* There are no other pointers to this temporary. */
5084 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
5086 else if (targetm.calls.promote_prototypes (type)
5087 && INTEGRAL_TYPE_P (type)
5088 && COMPLETE_TYPE_P (type)
5089 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5090 TYPE_SIZE (integer_type_node)))
5091 type = integer_type_node;
5096 /* Actually perform the appropriate conversion. */
5099 convert_for_arg_passing (tree type, tree val)
5103 /* If VAL is a bitfield, then -- since it has already been converted
5104 to TYPE -- it cannot have a precision greater than TYPE.
5106 If it has a smaller precision, we must widen it here. For
5107 example, passing "int f:3;" to a function expecting an "int" will
5108 not result in any conversion before this point.
5110 If the precision is the same we must not risk widening. For
5111 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5112 often have type "int", even though the C++ type for the field is
5113 "long long". If the value is being passed to a function
5114 expecting an "int", then no conversions will be required. But,
5115 if we call convert_bitfield_to_declared_type, the bitfield will
5116 be converted to "long long". */
5117 bitfield_type = is_bitfield_expr_with_lowered_type (val);
5119 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
5120 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
5122 if (val == error_mark_node)
5124 /* Pass classes with copy ctors by invisible reference. */
5125 else if (TREE_ADDRESSABLE (type))
5126 val = build1 (ADDR_EXPR, build_reference_type (type), val);
5127 else if (targetm.calls.promote_prototypes (type)
5128 && INTEGRAL_TYPE_P (type)
5129 && COMPLETE_TYPE_P (type)
5130 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5131 TYPE_SIZE (integer_type_node)))
5132 val = perform_integral_promotions (val);
5133 if (warn_missing_format_attribute)
5135 tree rhstype = TREE_TYPE (val);
5136 const enum tree_code coder = TREE_CODE (rhstype);
5137 const enum tree_code codel = TREE_CODE (type);
5138 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5140 && check_missing_format_attribute (type, rhstype))
5141 warning (OPT_Wmissing_format_attribute,
5142 "argument of function call might be a candidate for a format attribute");
5147 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5148 which no conversions at all should be done. This is true for some
5149 builtins which don't act like normal functions. */
5152 magic_varargs_p (tree fn)
5154 if (DECL_BUILT_IN (fn))
5155 switch (DECL_FUNCTION_CODE (fn))
5157 case BUILT_IN_CLASSIFY_TYPE:
5158 case BUILT_IN_CONSTANT_P:
5159 case BUILT_IN_NEXT_ARG:
5160 case BUILT_IN_VA_START:
5164 return lookup_attribute ("type generic",
5165 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
5171 /* Subroutine of the various build_*_call functions. Overload resolution
5172 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5173 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5174 bitmask of various LOOKUP_* flags which apply to the call itself. */
5177 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
5180 tree args = cand->args;
5181 conversion **convs = cand->convs;
5183 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
5191 bool already_used = false;
5193 /* In a template, there is no need to perform all of the work that
5194 is normally done. We are only interested in the type of the call
5195 expression, i.e., the return type of the function. Any semantic
5196 errors will be deferred until the template is instantiated. */
5197 if (processing_template_decl)
5201 return_type = TREE_TYPE (TREE_TYPE (fn));
5202 expr = build_call_list (return_type, build_addr_func (fn), args);
5203 if (TREE_THIS_VOLATILE (fn) && cfun)
5204 current_function_returns_abnormally = 1;
5205 if (!VOID_TYPE_P (return_type))
5206 require_complete_type (return_type);
5207 return convert_from_reference (expr);
5210 /* Give any warnings we noticed during overload resolution. */
5213 struct candidate_warning *w;
5214 for (w = cand->warnings; w; w = w->next)
5215 joust (cand, w->loser, 1);
5218 /* Make =delete work with SFINAE. */
5219 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
5220 return error_mark_node;
5222 if (DECL_FUNCTION_MEMBER_P (fn))
5224 /* If FN is a template function, two cases must be considered.
5229 template <class T> void f();
5231 template <class T> struct B {
5235 struct C : A, B<int> {
5237 using B<int>::g; // #2
5240 In case #1 where `A::f' is a member template, DECL_ACCESS is
5241 recorded in the primary template but not in its specialization.
5242 We check access of FN using its primary template.
5244 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5245 because it is a member of class template B, DECL_ACCESS is
5246 recorded in the specialization `B<int>::g'. We cannot use its
5247 primary template because `B<T>::g' and `B<int>::g' may have
5248 different access. */
5249 if (DECL_TEMPLATE_INFO (fn)
5250 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
5251 perform_or_defer_access_check (cand->access_path,
5252 DECL_TI_TEMPLATE (fn), fn);
5254 perform_or_defer_access_check (cand->access_path, fn, fn);
5257 if (args && TREE_CODE (args) != TREE_LIST)
5258 args = build_tree_list (NULL_TREE, args);
5261 /* Find maximum size of vector to hold converted arguments. */
5262 parmlen = list_length (parm);
5263 nargs = list_length (args);
5264 if (parmlen > nargs)
5266 argarray = (tree *) alloca (nargs * sizeof (tree));
5268 /* The implicit parameters to a constructor are not considered by overload
5269 resolution, and must be of the proper type. */
5270 if (DECL_CONSTRUCTOR_P (fn))
5272 argarray[j++] = TREE_VALUE (arg);
5273 arg = TREE_CHAIN (arg);
5274 parm = TREE_CHAIN (parm);
5275 /* We should never try to call the abstract constructor. */
5276 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
5278 if (DECL_HAS_VTT_PARM_P (fn))
5280 argarray[j++] = TREE_VALUE (arg);
5281 arg = TREE_CHAIN (arg);
5282 parm = TREE_CHAIN (parm);
5285 /* Bypass access control for 'this' parameter. */
5286 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5288 tree parmtype = TREE_VALUE (parm);
5289 tree argtype = TREE_TYPE (TREE_VALUE (arg));
5293 if (convs[i]->bad_p)
5295 if (complain & tf_error)
5296 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
5297 TREE_TYPE (argtype), fn);
5299 return error_mark_node;
5302 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5303 X is called for an object that is not of type X, or of a type
5304 derived from X, the behavior is undefined.
5306 So we can assume that anything passed as 'this' is non-null, and
5307 optimize accordingly. */
5308 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
5309 /* Convert to the base in which the function was declared. */
5310 gcc_assert (cand->conversion_path != NULL_TREE);
5311 converted_arg = build_base_path (PLUS_EXPR,
5313 cand->conversion_path,
5315 /* Check that the base class is accessible. */
5316 if (!accessible_base_p (TREE_TYPE (argtype),
5317 BINFO_TYPE (cand->conversion_path), true))
5318 error ("%qT is not an accessible base of %qT",
5319 BINFO_TYPE (cand->conversion_path),
5320 TREE_TYPE (argtype));
5321 /* If fn was found by a using declaration, the conversion path
5322 will be to the derived class, not the base declaring fn. We
5323 must convert from derived to base. */
5324 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
5325 TREE_TYPE (parmtype), ba_unique, NULL);
5326 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
5329 argarray[j++] = converted_arg;
5330 parm = TREE_CHAIN (parm);
5331 arg = TREE_CHAIN (arg);
5337 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
5339 tree type = TREE_VALUE (parm);
5343 /* Don't make a copy here if build_call is going to. */
5344 if (conv->kind == ck_rvalue
5345 && COMPLETE_TYPE_P (complete_type (type))
5346 && !TREE_ADDRESSABLE (type))
5347 conv = conv->u.next;
5349 /* Warn about initializer_list deduction that isn't currently in the
5351 if (cxx_dialect > cxx98
5352 && flag_deduce_init_list
5353 && cand->template_decl
5354 && is_std_init_list (non_reference (type)))
5356 tree tmpl = TI_TEMPLATE (cand->template_decl);
5357 tree realparm = DECL_ARGUMENTS (cand->fn);
5362 realparm = TREE_CHAIN (realparm);
5363 patparm = get_pattern_parm (realparm, tmpl);
5365 if (!is_std_init_list (non_reference (TREE_TYPE (patparm))))
5367 pedwarn (input_location, 0, "deducing %qT as %qT",
5368 non_reference (TREE_TYPE (patparm)),
5369 non_reference (type));
5370 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
5371 pedwarn (input_location, 0,
5372 " (you can disable this with -fno-deduce-init-list)");
5376 val = convert_like_with_context
5377 (conv, TREE_VALUE (arg), fn, i - is_method, complain);
5379 val = convert_for_arg_passing (type, val);
5380 if (val == error_mark_node)
5381 return error_mark_node;
5383 argarray[j++] = val;
5386 /* Default arguments */
5387 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
5388 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
5389 TREE_PURPOSE (parm),
5392 for (; arg; arg = TREE_CHAIN (arg))
5394 tree a = TREE_VALUE (arg);
5395 if (magic_varargs_p (fn))
5396 /* Do no conversions for magic varargs. */;
5398 a = convert_arg_to_ellipsis (a);
5402 gcc_assert (j <= nargs);
5405 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
5406 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
5408 /* Avoid actually calling copy constructors and copy assignment operators,
5411 if (! flag_elide_constructors)
5412 /* Do things the hard way. */;
5413 else if (cand->num_convs == 1
5414 && (DECL_COPY_CONSTRUCTOR_P (fn)
5415 || DECL_MOVE_CONSTRUCTOR_P (fn)))
5418 arg = argarray[num_artificial_parms_for (fn)];
5420 /* Pull out the real argument, disregarding const-correctness. */
5422 while (CONVERT_EXPR_P (targ)
5423 || TREE_CODE (targ) == NON_LVALUE_EXPR)
5424 targ = TREE_OPERAND (targ, 0);
5425 if (TREE_CODE (targ) == ADDR_EXPR)
5427 targ = TREE_OPERAND (targ, 0);
5428 if (!same_type_ignoring_top_level_qualifiers_p
5429 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
5438 arg = cp_build_indirect_ref (arg, 0, complain);
5440 if (TREE_CODE (arg) == TARGET_EXPR
5441 && TARGET_EXPR_LIST_INIT_P (arg))
5443 /* Copy-list-initialization doesn't require the copy constructor
5446 /* [class.copy]: the copy constructor is implicitly defined even if
5447 the implementation elided its use. */
5448 else if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
5451 already_used = true;
5454 /* If we're creating a temp and we already have one, don't create a
5455 new one. If we're not creating a temp but we get one, use
5456 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5457 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5458 temp or an INIT_EXPR otherwise. */
5459 if (integer_zerop (TREE_VALUE (args)))
5461 if (TREE_CODE (arg) == TARGET_EXPR)
5463 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5464 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
5466 else if (TREE_CODE (arg) == TARGET_EXPR
5467 || (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn))
5468 && !move_fn_p (fn)))
5470 tree to = stabilize_reference
5471 (cp_build_indirect_ref (TREE_VALUE (args), 0, complain));
5473 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
5477 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
5479 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
5481 tree to = stabilize_reference
5482 (cp_build_indirect_ref (argarray[0], 0, complain));
5483 tree type = TREE_TYPE (to);
5484 tree as_base = CLASSTYPE_AS_BASE (type);
5487 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
5489 arg = cp_build_indirect_ref (arg, 0, complain);
5490 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
5494 /* We must only copy the non-tail padding parts.
5495 Use __builtin_memcpy for the bitwise copy.
5496 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5497 instead of an explicit call to memcpy. */
5499 tree arg0, arg1, arg2, t;
5500 tree test = NULL_TREE;
5502 arg2 = TYPE_SIZE_UNIT (as_base);
5504 arg0 = cp_build_unary_op (ADDR_EXPR, to, 0, complain);
5506 if (!(optimize && flag_tree_ter))
5508 /* When TER is off get_pointer_alignment returns 0, so a call
5509 to __builtin_memcpy is expanded as a call to memcpy, which
5510 is invalid with identical args. When TER is on it is
5511 expanded as a block move, which should be safe. */
5512 arg0 = save_expr (arg0);
5513 arg1 = save_expr (arg1);
5514 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
5516 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
5517 t = build_call_n (t, 3, arg0, arg1, arg2);
5519 t = convert (TREE_TYPE (arg0), t);
5521 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
5522 val = cp_build_indirect_ref (t, 0, complain);
5531 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
5534 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
5537 gcc_assert (binfo && binfo != error_mark_node);
5539 /* Warn about deprecated virtual functions now, since we're about
5540 to throw away the decl. */
5541 if (TREE_DEPRECATED (fn))
5542 warn_deprecated_use (fn);
5544 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
5545 if (TREE_SIDE_EFFECTS (argarray[0]))
5546 argarray[0] = save_expr (argarray[0]);
5547 t = build_pointer_type (TREE_TYPE (fn));
5548 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5549 fn = build_java_interface_fn_ref (fn, argarray[0]);
5551 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
5555 fn = build_addr_func (fn);
5557 return build_cxx_call (fn, nargs, argarray);
5560 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5561 This function performs no overload resolution, conversion, or other
5562 high-level operations. */
5565 build_cxx_call (tree fn, int nargs, tree *argarray)
5569 fn = build_call_a (fn, nargs, argarray);
5571 /* If this call might throw an exception, note that fact. */
5572 fndecl = get_callee_fndecl (fn);
5573 if ((!fndecl || !TREE_NOTHROW (fndecl))
5574 && at_function_scope_p ()
5576 cp_function_chain->can_throw = 1;
5578 /* Check that arguments to builtin functions match the expectations. */
5580 && DECL_BUILT_IN (fndecl)
5581 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
5582 && !check_builtin_function_arguments (fndecl, nargs, argarray))
5583 return error_mark_node;
5585 /* Some built-in function calls will be evaluated at compile-time in
5587 fn = fold_if_not_in_template (fn);
5589 if (VOID_TYPE_P (TREE_TYPE (fn)))
5592 fn = require_complete_type (fn);
5593 if (fn == error_mark_node)
5594 return error_mark_node;
5596 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
5597 fn = build_cplus_new (TREE_TYPE (fn), fn);
5598 return convert_from_reference (fn);
5601 static GTY(()) tree java_iface_lookup_fn;
5603 /* Make an expression which yields the address of the Java interface
5604 method FN. This is achieved by generating a call to libjava's
5605 _Jv_LookupInterfaceMethodIdx(). */
5608 build_java_interface_fn_ref (tree fn, tree instance)
5610 tree lookup_fn, method, idx;
5611 tree klass_ref, iface, iface_ref;
5614 if (!java_iface_lookup_fn)
5616 tree endlink = build_void_list_node ();
5617 tree t = tree_cons (NULL_TREE, ptr_type_node,
5618 tree_cons (NULL_TREE, ptr_type_node,
5619 tree_cons (NULL_TREE, java_int_type_node,
5621 java_iface_lookup_fn
5622 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx",
5623 build_function_type (ptr_type_node, t),
5624 0, NOT_BUILT_IN, NULL, NULL_TREE);
5627 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5628 This is the first entry in the vtable. */
5629 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, 0,
5630 tf_warning_or_error),
5633 /* Get the java.lang.Class pointer for the interface being called. */
5634 iface = DECL_CONTEXT (fn);
5635 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5636 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5637 || DECL_CONTEXT (iface_ref) != iface)
5639 error ("could not find class$ field in java interface type %qT",
5641 return error_mark_node;
5643 iface_ref = build_address (iface_ref);
5644 iface_ref = convert (build_pointer_type (iface), iface_ref);
5646 /* Determine the itable index of FN. */
5648 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5650 if (!DECL_VIRTUAL_P (method))
5656 idx = build_int_cst (NULL_TREE, i);
5658 lookup_fn = build1 (ADDR_EXPR,
5659 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5660 java_iface_lookup_fn);
5661 return build_call_nary (ptr_type_node, lookup_fn,
5662 3, klass_ref, iface_ref, idx);
5665 /* Returns the value to use for the in-charge parameter when making a
5666 call to a function with the indicated NAME.
5668 FIXME:Can't we find a neater way to do this mapping? */
5671 in_charge_arg_for_name (tree name)
5673 if (name == base_ctor_identifier
5674 || name == base_dtor_identifier)
5675 return integer_zero_node;
5676 else if (name == complete_ctor_identifier)
5677 return integer_one_node;
5678 else if (name == complete_dtor_identifier)
5679 return integer_two_node;
5680 else if (name == deleting_dtor_identifier)
5681 return integer_three_node;
5683 /* This function should only be called with one of the names listed
5689 /* Build a call to a constructor, destructor, or an assignment
5690 operator for INSTANCE, an expression with class type. NAME
5691 indicates the special member function to call; ARGS are the
5692 arguments. BINFO indicates the base of INSTANCE that is to be
5693 passed as the `this' parameter to the member function called.
5695 FLAGS are the LOOKUP_* flags to use when processing the call.
5697 If NAME indicates a complete object constructor, INSTANCE may be
5698 NULL_TREE. In this case, the caller will call build_cplus_new to
5699 store the newly constructed object into a VAR_DECL. */
5702 build_special_member_call (tree instance, tree name, tree args,
5703 tree binfo, int flags, tsubst_flags_t complain)
5706 /* The type of the subobject to be constructed or destroyed. */
5709 gcc_assert (name == complete_ctor_identifier
5710 || name == base_ctor_identifier
5711 || name == complete_dtor_identifier
5712 || name == base_dtor_identifier
5713 || name == deleting_dtor_identifier
5714 || name == ansi_assopname (NOP_EXPR));
5717 /* Resolve the name. */
5718 if (!complete_type_or_else (binfo, NULL_TREE))
5719 return error_mark_node;
5721 binfo = TYPE_BINFO (binfo);
5724 gcc_assert (binfo != NULL_TREE);
5726 class_type = BINFO_TYPE (binfo);
5728 /* Handle the special case where INSTANCE is NULL_TREE. */
5729 if (name == complete_ctor_identifier && !instance)
5731 instance = build_int_cst (build_pointer_type (class_type), 0);
5732 instance = build1 (INDIRECT_REF, class_type, instance);
5736 if (name == complete_dtor_identifier
5737 || name == base_dtor_identifier
5738 || name == deleting_dtor_identifier)
5739 gcc_assert (args == NULL_TREE);
5741 /* Convert to the base class, if necessary. */
5742 if (!same_type_ignoring_top_level_qualifiers_p
5743 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5745 if (name != ansi_assopname (NOP_EXPR))
5746 /* For constructors and destructors, either the base is
5747 non-virtual, or it is virtual but we are doing the
5748 conversion from a constructor or destructor for the
5749 complete object. In either case, we can convert
5751 instance = convert_to_base_statically (instance, binfo);
5753 /* However, for assignment operators, we must convert
5754 dynamically if the base is virtual. */
5755 instance = build_base_path (PLUS_EXPR, instance,
5756 binfo, /*nonnull=*/1);
5760 gcc_assert (instance != NULL_TREE);
5762 fns = lookup_fnfields (binfo, name, 1);
5764 /* When making a call to a constructor or destructor for a subobject
5765 that uses virtual base classes, pass down a pointer to a VTT for
5767 if ((name == base_ctor_identifier
5768 || name == base_dtor_identifier)
5769 && CLASSTYPE_VBASECLASSES (class_type))
5774 /* If the current function is a complete object constructor
5775 or destructor, then we fetch the VTT directly.
5776 Otherwise, we look it up using the VTT we were given. */
5777 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5778 vtt = decay_conversion (vtt);
5779 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5780 build2 (EQ_EXPR, boolean_type_node,
5781 current_in_charge_parm, integer_zero_node),
5784 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5785 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
5786 BINFO_SUBVTT_INDEX (binfo));
5788 args = tree_cons (NULL_TREE, sub_vtt, args);
5791 return build_new_method_call (instance, fns, args,
5792 TYPE_BINFO (BINFO_TYPE (binfo)),
5797 /* Return the NAME, as a C string. The NAME indicates a function that
5798 is a member of TYPE. *FREE_P is set to true if the caller must
5799 free the memory returned.
5801 Rather than go through all of this, we should simply set the names
5802 of constructors and destructors appropriately, and dispense with
5803 ctor_identifier, dtor_identifier, etc. */
5806 name_as_c_string (tree name, tree type, bool *free_p)
5810 /* Assume that we will not allocate memory. */
5812 /* Constructors and destructors are special. */
5813 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5816 = CONST_CAST (char *, IDENTIFIER_POINTER (constructor_name (type)));
5817 /* For a destructor, add the '~'. */
5818 if (name == complete_dtor_identifier
5819 || name == base_dtor_identifier
5820 || name == deleting_dtor_identifier)
5822 pretty_name = concat ("~", pretty_name, NULL);
5823 /* Remember that we need to free the memory allocated. */
5827 else if (IDENTIFIER_TYPENAME_P (name))
5829 pretty_name = concat ("operator ",
5830 type_as_string (TREE_TYPE (name),
5831 TFF_PLAIN_IDENTIFIER),
5833 /* Remember that we need to free the memory allocated. */
5837 pretty_name = CONST_CAST (char *, IDENTIFIER_POINTER (name));
5842 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5843 be set, upon return, to the function called. */
5846 build_new_method_call (tree instance, tree fns, tree args,
5847 tree conversion_path, int flags,
5848 tree *fn_p, tsubst_flags_t complain)
5850 struct z_candidate *candidates = 0, *cand;
5851 tree explicit_targs = NULL_TREE;
5852 tree basetype = NULL_TREE;
5855 tree mem_args = NULL_TREE, instance_ptr;
5861 int template_only = 0;
5868 gcc_assert (instance != NULL_TREE);
5870 /* We don't know what function we're going to call, yet. */
5874 if (error_operand_p (instance)
5875 || error_operand_p (fns)
5876 || args == error_mark_node)
5877 return error_mark_node;
5879 if (!BASELINK_P (fns))
5881 if (complain & tf_error)
5882 error ("call to non-function %qD", fns);
5883 return error_mark_node;
5886 orig_instance = instance;
5890 /* Dismantle the baselink to collect all the information we need. */
5891 if (!conversion_path)
5892 conversion_path = BASELINK_BINFO (fns);
5893 access_binfo = BASELINK_ACCESS_BINFO (fns);
5894 optype = BASELINK_OPTYPE (fns);
5895 fns = BASELINK_FUNCTIONS (fns);
5896 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5898 explicit_targs = TREE_OPERAND (fns, 1);
5899 fns = TREE_OPERAND (fns, 0);
5902 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5903 || TREE_CODE (fns) == TEMPLATE_DECL
5904 || TREE_CODE (fns) == OVERLOAD);
5905 fn = get_first_fn (fns);
5906 name = DECL_NAME (fn);
5908 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5909 gcc_assert (CLASS_TYPE_P (basetype));
5911 if (processing_template_decl)
5913 instance = build_non_dependent_expr (instance);
5914 args = build_non_dependent_args (orig_args);
5917 /* The USER_ARGS are the arguments we will display to users if an
5918 error occurs. The USER_ARGS should not include any
5919 compiler-generated arguments. The "this" pointer hasn't been
5920 added yet. However, we must remove the VTT pointer if this is a
5921 call to a base-class constructor or destructor. */
5923 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5925 /* Callers should explicitly indicate whether they want to construct
5926 the complete object or just the part without virtual bases. */
5927 gcc_assert (name != ctor_identifier);
5928 /* Similarly for destructors. */
5929 gcc_assert (name != dtor_identifier);
5930 /* Remove the VTT pointer, if present. */
5931 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5932 && CLASSTYPE_VBASECLASSES (basetype))
5933 user_args = TREE_CHAIN (user_args);
5936 /* Process the argument list. */
5937 args = resolve_args (args);
5938 if (args == error_mark_node)
5939 return error_mark_node;
5941 instance_ptr = build_this (instance);
5943 /* It's OK to call destructors and constructors on cv-qualified objects.
5944 Therefore, convert the INSTANCE_PTR to the unqualified type, if
5946 if (DECL_DESTRUCTOR_P (fn)
5947 || DECL_CONSTRUCTOR_P (fn))
5949 tree type = build_pointer_type (basetype);
5950 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5951 instance_ptr = build_nop (type, instance_ptr);
5953 if (DECL_DESTRUCTOR_P (fn))
5954 name = complete_dtor_identifier;
5956 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
5957 initializer, not T({ }). If the type doesn't have a list ctor,
5958 break apart the list into separate ctor args. */
5959 if (DECL_CONSTRUCTOR_P (fn) && args
5960 && BRACE_ENCLOSED_INITIALIZER_P (TREE_VALUE (args))
5961 && CONSTRUCTOR_IS_DIRECT_INIT (TREE_VALUE (args))
5962 && !TYPE_HAS_LIST_CTOR (basetype))
5964 gcc_assert (TREE_CHAIN (args) == NULL_TREE);
5965 args = ctor_to_list (TREE_VALUE (args));
5968 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5969 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5971 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5972 p = conversion_obstack_alloc (0);
5974 for (fn = fns; fn; fn = OVL_NEXT (fn))
5976 tree t = OVL_CURRENT (fn);
5979 /* We can end up here for copy-init of same or base class. */
5980 if ((flags & LOOKUP_ONLYCONVERTING)
5981 && DECL_NONCONVERTING_P (t))
5984 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5985 this_arglist = mem_args;
5987 this_arglist = args;
5989 if (TREE_CODE (t) == TEMPLATE_DECL)
5990 /* A member template. */
5991 add_template_candidate (&candidates, t,
5994 this_arglist, optype,
5999 else if (! template_only)
6000 add_function_candidate (&candidates, t,
6008 candidates = splice_viable (candidates, pedantic, &any_viable_p);
6011 if (complain & tf_error)
6013 if (!COMPLETE_TYPE_P (basetype))
6014 cxx_incomplete_type_error (instance_ptr, basetype);
6020 pretty_name = name_as_c_string (name, basetype, &free_p);
6021 error ("no matching function for call to %<%T::%s(%A)%#V%>",
6022 basetype, pretty_name, user_args,
6023 TREE_TYPE (TREE_TYPE (instance_ptr)));
6027 print_z_candidates (candidates);
6029 call = error_mark_node;
6033 cand = tourney (candidates);
6039 if (complain & tf_error)
6041 pretty_name = name_as_c_string (name, basetype, &free_p);
6042 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
6044 print_z_candidates (candidates);
6048 call = error_mark_node;
6054 if (!(flags & LOOKUP_NONVIRTUAL)
6055 && DECL_PURE_VIRTUAL_P (fn)
6056 && instance == current_class_ref
6057 && (DECL_CONSTRUCTOR_P (current_function_decl)
6058 || DECL_DESTRUCTOR_P (current_function_decl))
6059 && (complain & tf_warning))
6060 /* This is not an error, it is runtime undefined
6062 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
6063 "abstract virtual %q#D called from constructor"
6064 : "abstract virtual %q#D called from destructor"),
6067 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
6068 && is_dummy_object (instance_ptr))
6070 if (complain & tf_error)
6071 error ("cannot call member function %qD without object",
6073 call = error_mark_node;
6077 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
6078 && resolves_to_fixed_type_p (instance, 0))
6079 flags |= LOOKUP_NONVIRTUAL;
6080 /* Now we know what function is being called. */
6083 /* Build the actual CALL_EXPR. */
6084 call = build_over_call (cand, flags, complain);
6085 /* In an expression of the form `a->f()' where `f' turns
6086 out to be a static member function, `a' is
6087 none-the-less evaluated. */
6088 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
6089 && !is_dummy_object (instance_ptr)
6090 && TREE_SIDE_EFFECTS (instance_ptr))
6091 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
6092 instance_ptr, call);
6093 else if (call != error_mark_node
6094 && DECL_DESTRUCTOR_P (cand->fn)
6095 && !VOID_TYPE_P (TREE_TYPE (call)))
6096 /* An explicit call of the form "x->~X()" has type
6097 "void". However, on platforms where destructors
6098 return "this" (i.e., those where
6099 targetm.cxx.cdtor_returns_this is true), such calls
6100 will appear to have a return value of pointer type
6101 to the low-level call machinery. We do not want to
6102 change the low-level machinery, since we want to be
6103 able to optimize "delete f()" on such platforms as
6104 "operator delete(~X(f()))" (rather than generating
6105 "t = f(), ~X(t), operator delete (t)"). */
6106 call = build_nop (void_type_node, call);
6111 if (processing_template_decl && call != error_mark_node)
6113 bool cast_to_void = false;
6115 if (TREE_CODE (call) == COMPOUND_EXPR)
6116 call = TREE_OPERAND (call, 1);
6117 else if (TREE_CODE (call) == NOP_EXPR)
6119 cast_to_void = true;
6120 call = TREE_OPERAND (call, 0);
6122 if (TREE_CODE (call) == INDIRECT_REF)
6123 call = TREE_OPERAND (call, 0);
6124 call = (build_min_non_dep_call_list
6126 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
6127 orig_instance, orig_fns, NULL_TREE),
6129 call = convert_from_reference (call);
6131 call = build_nop (void_type_node, call);
6134 /* Free all the conversions we allocated. */
6135 obstack_free (&conversion_obstack, p);
6140 /* Returns true iff standard conversion sequence ICS1 is a proper
6141 subsequence of ICS2. */
6144 is_subseq (conversion *ics1, conversion *ics2)
6146 /* We can assume that a conversion of the same code
6147 between the same types indicates a subsequence since we only get
6148 here if the types we are converting from are the same. */
6150 while (ics1->kind == ck_rvalue
6151 || ics1->kind == ck_lvalue)
6152 ics1 = ics1->u.next;
6156 while (ics2->kind == ck_rvalue
6157 || ics2->kind == ck_lvalue)
6158 ics2 = ics2->u.next;
6160 if (ics2->kind == ck_user
6161 || ics2->kind == ck_ambig
6162 || ics2->kind == ck_identity)
6163 /* At this point, ICS1 cannot be a proper subsequence of
6164 ICS2. We can get a USER_CONV when we are comparing the
6165 second standard conversion sequence of two user conversion
6169 ics2 = ics2->u.next;
6171 if (ics2->kind == ics1->kind
6172 && same_type_p (ics2->type, ics1->type)
6173 && same_type_p (ics2->u.next->type,
6174 ics1->u.next->type))
6179 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6180 be any _TYPE nodes. */
6183 is_properly_derived_from (tree derived, tree base)
6185 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
6188 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6189 considers every class derived from itself. */
6190 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
6191 && DERIVED_FROM_P (base, derived));
6194 /* We build the ICS for an implicit object parameter as a pointer
6195 conversion sequence. However, such a sequence should be compared
6196 as if it were a reference conversion sequence. If ICS is the
6197 implicit conversion sequence for an implicit object parameter,
6198 modify it accordingly. */
6201 maybe_handle_implicit_object (conversion **ics)
6205 /* [over.match.funcs]
6207 For non-static member functions, the type of the
6208 implicit object parameter is "reference to cv X"
6209 where X is the class of which the function is a
6210 member and cv is the cv-qualification on the member
6211 function declaration. */
6212 conversion *t = *ics;
6213 tree reference_type;
6215 /* The `this' parameter is a pointer to a class type. Make the
6216 implicit conversion talk about a reference to that same class
6218 reference_type = TREE_TYPE (t->type);
6219 reference_type = build_reference_type (reference_type);
6221 if (t->kind == ck_qual)
6223 if (t->kind == ck_ptr)
6225 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
6226 t = direct_reference_binding (reference_type, t);
6228 t->rvaluedness_matches_p = 0;
6233 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6234 and return the initial reference binding conversion. Otherwise,
6235 leave *ICS unchanged and return NULL. */
6238 maybe_handle_ref_bind (conversion **ics)
6240 if ((*ics)->kind == ck_ref_bind)
6242 conversion *old_ics = *ics;
6243 *ics = old_ics->u.next;
6244 (*ics)->user_conv_p = old_ics->user_conv_p;
6245 (*ics)->bad_p = old_ics->bad_p;
6252 /* Compare two implicit conversion sequences according to the rules set out in
6253 [over.ics.rank]. Return values:
6255 1: ics1 is better than ics2
6256 -1: ics2 is better than ics1
6257 0: ics1 and ics2 are indistinguishable */
6260 compare_ics (conversion *ics1, conversion *ics2)
6266 tree deref_from_type1 = NULL_TREE;
6267 tree deref_from_type2 = NULL_TREE;
6268 tree deref_to_type1 = NULL_TREE;
6269 tree deref_to_type2 = NULL_TREE;
6270 conversion_rank rank1, rank2;
6272 /* REF_BINDING is nonzero if the result of the conversion sequence
6273 is a reference type. In that case REF_CONV is the reference
6274 binding conversion. */
6275 conversion *ref_conv1;
6276 conversion *ref_conv2;
6278 /* Handle implicit object parameters. */
6279 maybe_handle_implicit_object (&ics1);
6280 maybe_handle_implicit_object (&ics2);
6282 /* Handle reference parameters. */
6283 ref_conv1 = maybe_handle_ref_bind (&ics1);
6284 ref_conv2 = maybe_handle_ref_bind (&ics2);
6286 /* List-initialization sequence L1 is a better conversion sequence than
6287 list-initialization sequence L2 if L1 converts to
6288 std::initializer_list<X> for some X and L2 does not. */
6289 if (ics1->kind == ck_list && ics2->kind != ck_list)
6291 if (ics2->kind == ck_list && ics1->kind != ck_list)
6296 When comparing the basic forms of implicit conversion sequences (as
6297 defined in _over.best.ics_)
6299 --a standard conversion sequence (_over.ics.scs_) is a better
6300 conversion sequence than a user-defined conversion sequence
6301 or an ellipsis conversion sequence, and
6303 --a user-defined conversion sequence (_over.ics.user_) is a
6304 better conversion sequence than an ellipsis conversion sequence
6305 (_over.ics.ellipsis_). */
6306 rank1 = CONVERSION_RANK (ics1);
6307 rank2 = CONVERSION_RANK (ics2);
6311 else if (rank1 < rank2)
6314 if (rank1 == cr_bad)
6316 /* XXX Isn't this an extension? */
6317 /* Both ICS are bad. We try to make a decision based on what
6318 would have happened if they'd been good. */
6319 if (ics1->user_conv_p > ics2->user_conv_p
6320 || ics1->rank > ics2->rank)
6322 else if (ics1->user_conv_p < ics2->user_conv_p
6323 || ics1->rank < ics2->rank)
6326 /* We couldn't make up our minds; try to figure it out below. */
6329 if (ics1->ellipsis_p || ics1->kind == ck_list)
6330 /* Both conversions are ellipsis conversions or both are building a
6331 std::initializer_list. */
6334 /* User-defined conversion sequence U1 is a better conversion sequence
6335 than another user-defined conversion sequence U2 if they contain the
6336 same user-defined conversion operator or constructor and if the sec-
6337 ond standard conversion sequence of U1 is better than the second
6338 standard conversion sequence of U2. */
6340 if (ics1->user_conv_p)
6345 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
6346 if (t1->kind == ck_ambig || t1->kind == ck_aggr)
6348 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
6349 if (t2->kind == ck_ambig || t2->kind == ck_aggr)
6352 if (t1->cand->fn != t2->cand->fn)
6355 /* We can just fall through here, after setting up
6356 FROM_TYPE1 and FROM_TYPE2. */
6357 from_type1 = t1->type;
6358 from_type2 = t2->type;
6365 /* We're dealing with two standard conversion sequences.
6369 Standard conversion sequence S1 is a better conversion
6370 sequence than standard conversion sequence S2 if
6372 --S1 is a proper subsequence of S2 (comparing the conversion
6373 sequences in the canonical form defined by _over.ics.scs_,
6374 excluding any Lvalue Transformation; the identity
6375 conversion sequence is considered to be a subsequence of
6376 any non-identity conversion sequence */
6379 while (t1->kind != ck_identity)
6381 from_type1 = t1->type;
6384 while (t2->kind != ck_identity)
6386 from_type2 = t2->type;
6389 /* One sequence can only be a subsequence of the other if they start with
6390 the same type. They can start with different types when comparing the
6391 second standard conversion sequence in two user-defined conversion
6393 if (same_type_p (from_type1, from_type2))
6395 if (is_subseq (ics1, ics2))
6397 if (is_subseq (ics2, ics1))
6405 --the rank of S1 is better than the rank of S2 (by the rules
6408 Standard conversion sequences are ordered by their ranks: an Exact
6409 Match is a better conversion than a Promotion, which is a better
6410 conversion than a Conversion.
6412 Two conversion sequences with the same rank are indistinguishable
6413 unless one of the following rules applies:
6415 --A conversion that is not a conversion of a pointer, or pointer
6416 to member, to bool is better than another conversion that is such
6419 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
6420 so that we do not have to check it explicitly. */
6421 if (ics1->rank < ics2->rank)
6423 else if (ics2->rank < ics1->rank)
6426 to_type1 = ics1->type;
6427 to_type2 = ics2->type;
6429 /* A conversion from scalar arithmetic type to complex is worse than a
6430 conversion between scalar arithmetic types. */
6431 if (same_type_p (from_type1, from_type2)
6432 && ARITHMETIC_TYPE_P (from_type1)
6433 && ARITHMETIC_TYPE_P (to_type1)
6434 && ARITHMETIC_TYPE_P (to_type2)
6435 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
6436 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
6438 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
6444 if (TYPE_PTR_P (from_type1)
6445 && TYPE_PTR_P (from_type2)
6446 && TYPE_PTR_P (to_type1)
6447 && TYPE_PTR_P (to_type2))
6449 deref_from_type1 = TREE_TYPE (from_type1);
6450 deref_from_type2 = TREE_TYPE (from_type2);
6451 deref_to_type1 = TREE_TYPE (to_type1);
6452 deref_to_type2 = TREE_TYPE (to_type2);
6454 /* The rules for pointers to members A::* are just like the rules
6455 for pointers A*, except opposite: if B is derived from A then
6456 A::* converts to B::*, not vice versa. For that reason, we
6457 switch the from_ and to_ variables here. */
6458 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
6459 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
6460 || (TYPE_PTRMEMFUNC_P (from_type1)
6461 && TYPE_PTRMEMFUNC_P (from_type2)
6462 && TYPE_PTRMEMFUNC_P (to_type1)
6463 && TYPE_PTRMEMFUNC_P (to_type2)))
6465 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
6466 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
6467 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
6468 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
6471 if (deref_from_type1 != NULL_TREE
6472 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
6473 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
6475 /* This was one of the pointer or pointer-like conversions.
6479 --If class B is derived directly or indirectly from class A,
6480 conversion of B* to A* is better than conversion of B* to
6481 void*, and conversion of A* to void* is better than
6482 conversion of B* to void*. */
6483 if (TREE_CODE (deref_to_type1) == VOID_TYPE
6484 && TREE_CODE (deref_to_type2) == VOID_TYPE)
6486 if (is_properly_derived_from (deref_from_type1,
6489 else if (is_properly_derived_from (deref_from_type2,
6493 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
6494 || TREE_CODE (deref_to_type2) == VOID_TYPE)
6496 if (same_type_p (deref_from_type1, deref_from_type2))
6498 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
6500 if (is_properly_derived_from (deref_from_type1,
6504 /* We know that DEREF_TO_TYPE1 is `void' here. */
6505 else if (is_properly_derived_from (deref_from_type1,
6510 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
6511 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
6515 --If class B is derived directly or indirectly from class A
6516 and class C is derived directly or indirectly from B,
6518 --conversion of C* to B* is better than conversion of C* to
6521 --conversion of B* to A* is better than conversion of C* to
6523 if (same_type_p (deref_from_type1, deref_from_type2))
6525 if (is_properly_derived_from (deref_to_type1,
6528 else if (is_properly_derived_from (deref_to_type2,
6532 else if (same_type_p (deref_to_type1, deref_to_type2))
6534 if (is_properly_derived_from (deref_from_type2,
6537 else if (is_properly_derived_from (deref_from_type1,
6543 else if (CLASS_TYPE_P (non_reference (from_type1))
6544 && same_type_p (from_type1, from_type2))
6546 tree from = non_reference (from_type1);
6550 --binding of an expression of type C to a reference of type
6551 B& is better than binding an expression of type C to a
6552 reference of type A&
6554 --conversion of C to B is better than conversion of C to A, */
6555 if (is_properly_derived_from (from, to_type1)
6556 && is_properly_derived_from (from, to_type2))
6558 if (is_properly_derived_from (to_type1, to_type2))
6560 else if (is_properly_derived_from (to_type2, to_type1))
6564 else if (CLASS_TYPE_P (non_reference (to_type1))
6565 && same_type_p (to_type1, to_type2))
6567 tree to = non_reference (to_type1);
6571 --binding of an expression of type B to a reference of type
6572 A& is better than binding an expression of type C to a
6573 reference of type A&,
6575 --conversion of B to A is better than conversion of C to A */
6576 if (is_properly_derived_from (from_type1, to)
6577 && is_properly_derived_from (from_type2, to))
6579 if (is_properly_derived_from (from_type2, from_type1))
6581 else if (is_properly_derived_from (from_type1, from_type2))
6588 --S1 and S2 differ only in their qualification conversion and yield
6589 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6590 qualification signature of type T1 is a proper subset of the cv-
6591 qualification signature of type T2 */
6592 if (ics1->kind == ck_qual
6593 && ics2->kind == ck_qual
6594 && same_type_p (from_type1, from_type2))
6596 int result = comp_cv_qual_signature (to_type1, to_type2);
6603 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6604 to an implicit object parameter, and either S1 binds an lvalue reference
6605 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6606 reference to an rvalue and S2 binds an lvalue reference
6607 (C++0x draft standard, 13.3.3.2)
6609 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6610 types to which the references refer are the same type except for
6611 top-level cv-qualifiers, and the type to which the reference
6612 initialized by S2 refers is more cv-qualified than the type to
6613 which the reference initialized by S1 refers */
6615 if (ref_conv1 && ref_conv2)
6617 if (!ref_conv1->this_p && !ref_conv2->this_p
6618 && (TYPE_REF_IS_RVALUE (ref_conv1->type)
6619 != TYPE_REF_IS_RVALUE (ref_conv2->type)))
6621 if (ref_conv1->rvaluedness_matches_p)
6623 if (ref_conv2->rvaluedness_matches_p)
6627 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
6628 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
6629 TREE_TYPE (ref_conv1->type));
6632 /* Neither conversion sequence is better than the other. */
6636 /* The source type for this standard conversion sequence. */
6639 source_type (conversion *t)
6641 for (;; t = t->u.next)
6643 if (t->kind == ck_user
6644 || t->kind == ck_ambig
6645 || t->kind == ck_identity)
6651 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6652 a pointer to LOSER and re-running joust to produce the warning if WINNER
6653 is actually used. */
6656 add_warning (struct z_candidate *winner, struct z_candidate *loser)
6658 candidate_warning *cw = (candidate_warning *)
6659 conversion_obstack_alloc (sizeof (candidate_warning));
6661 cw->next = winner->warnings;
6662 winner->warnings = cw;
6665 /* Compare two candidates for overloading as described in
6666 [over.match.best]. Return values:
6668 1: cand1 is better than cand2
6669 -1: cand2 is better than cand1
6670 0: cand1 and cand2 are indistinguishable */
6673 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
6676 int off1 = 0, off2 = 0;
6680 /* Candidates that involve bad conversions are always worse than those
6682 if (cand1->viable > cand2->viable)
6684 if (cand1->viable < cand2->viable)
6687 /* If we have two pseudo-candidates for conversions to the same type,
6688 or two candidates for the same function, arbitrarily pick one. */
6689 if (cand1->fn == cand2->fn
6690 && (IS_TYPE_OR_DECL_P (cand1->fn)))
6693 /* a viable function F1
6694 is defined to be a better function than another viable function F2 if
6695 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6696 ICSi(F2), and then */
6698 /* for some argument j, ICSj(F1) is a better conversion sequence than
6701 /* For comparing static and non-static member functions, we ignore
6702 the implicit object parameter of the non-static function. The
6703 standard says to pretend that the static function has an object
6704 parm, but that won't work with operator overloading. */
6705 len = cand1->num_convs;
6706 if (len != cand2->num_convs)
6708 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
6709 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
6711 gcc_assert (static_1 != static_2);
6722 for (i = 0; i < len; ++i)
6724 conversion *t1 = cand1->convs[i + off1];
6725 conversion *t2 = cand2->convs[i + off2];
6726 int comp = compare_ics (t1, t2);
6731 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
6732 == cr_std + cr_promotion)
6733 && t1->kind == ck_std
6734 && t2->kind == ck_std
6735 && TREE_CODE (t1->type) == INTEGER_TYPE
6736 && TREE_CODE (t2->type) == INTEGER_TYPE
6737 && (TYPE_PRECISION (t1->type)
6738 == TYPE_PRECISION (t2->type))
6739 && (TYPE_UNSIGNED (t1->u.next->type)
6740 || (TREE_CODE (t1->u.next->type)
6743 tree type = t1->u.next->type;
6745 struct z_candidate *w, *l;
6747 type1 = t1->type, type2 = t2->type,
6748 w = cand1, l = cand2;
6750 type1 = t2->type, type2 = t1->type,
6751 w = cand2, l = cand1;
6755 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
6756 type, type1, type2);
6757 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
6763 if (winner && comp != winner)
6772 /* warn about confusing overload resolution for user-defined conversions,
6773 either between a constructor and a conversion op, or between two
6775 if (winner && warn_conversion && cand1->second_conv
6776 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
6777 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
6779 struct z_candidate *w, *l;
6780 bool give_warning = false;
6783 w = cand1, l = cand2;
6785 w = cand2, l = cand1;
6787 /* We don't want to complain about `X::operator T1 ()'
6788 beating `X::operator T2 () const', when T2 is a no less
6789 cv-qualified version of T1. */
6790 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
6791 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
6793 tree t = TREE_TYPE (TREE_TYPE (l->fn));
6794 tree f = TREE_TYPE (TREE_TYPE (w->fn));
6796 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6801 if (!comp_ptr_ttypes (t, f))
6802 give_warning = true;
6805 give_warning = true;
6811 tree source = source_type (w->convs[0]);
6812 if (! DECL_CONSTRUCTOR_P (w->fn))
6813 source = TREE_TYPE (source);
6814 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
6815 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
6816 source, w->second_conv->type))
6818 inform (input_location, " because conversion sequence for the argument is better");
6829 F1 is a non-template function and F2 is a template function
6832 if (!cand1->template_decl && cand2->template_decl)
6834 else if (cand1->template_decl && !cand2->template_decl)
6838 F1 and F2 are template functions and the function template for F1 is
6839 more specialized than the template for F2 according to the partial
6842 if (cand1->template_decl && cand2->template_decl)
6844 winner = more_specialized_fn
6845 (TI_TEMPLATE (cand1->template_decl),
6846 TI_TEMPLATE (cand2->template_decl),
6847 /* [temp.func.order]: The presence of unused ellipsis and default
6848 arguments has no effect on the partial ordering of function
6849 templates. add_function_candidate() will not have
6850 counted the "this" argument for constructors. */
6851 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
6857 the context is an initialization by user-defined conversion (see
6858 _dcl.init_ and _over.match.user_) and the standard conversion
6859 sequence from the return type of F1 to the destination type (i.e.,
6860 the type of the entity being initialized) is a better conversion
6861 sequence than the standard conversion sequence from the return type
6862 of F2 to the destination type. */
6864 if (cand1->second_conv)
6866 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6871 /* Check whether we can discard a builtin candidate, either because we
6872 have two identical ones or matching builtin and non-builtin candidates.
6874 (Pedantically in the latter case the builtin which matched the user
6875 function should not be added to the overload set, but we spot it here.
6878 ... the builtin candidates include ...
6879 - do not have the same parameter type list as any non-template
6880 non-member candidate. */
6882 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6883 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6885 for (i = 0; i < len; ++i)
6886 if (!same_type_p (cand1->convs[i]->type,
6887 cand2->convs[i]->type))
6889 if (i == cand1->num_convs)
6891 if (cand1->fn == cand2->fn)
6892 /* Two built-in candidates; arbitrarily pick one. */
6894 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6895 /* cand1 is built-in; prefer cand2. */
6898 /* cand2 is built-in; prefer cand1. */
6903 /* If the two function declarations represent the same function (this can
6904 happen with declarations in multiple scopes and arg-dependent lookup),
6905 arbitrarily choose one. But first make sure the default args we're
6907 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6908 && equal_functions (cand1->fn, cand2->fn))
6910 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
6911 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
6913 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
6915 for (i = 0; i < len; ++i)
6917 /* Don't crash if the fn is variadic. */
6920 parms1 = TREE_CHAIN (parms1);
6921 parms2 = TREE_CHAIN (parms2);
6925 parms1 = TREE_CHAIN (parms1);
6927 parms2 = TREE_CHAIN (parms2);
6931 if (!cp_tree_equal (TREE_PURPOSE (parms1),
6932 TREE_PURPOSE (parms2)))
6936 permerror (input_location, "default argument mismatch in "
6937 "overload resolution");
6938 inform (input_location,
6939 " candidate 1: %q+#F", cand1->fn);
6940 inform (input_location,
6941 " candidate 2: %q+#F", cand2->fn);
6944 add_warning (cand1, cand2);
6947 parms1 = TREE_CHAIN (parms1);
6948 parms2 = TREE_CHAIN (parms2);
6956 /* Extension: If the worst conversion for one candidate is worse than the
6957 worst conversion for the other, take the first. */
6960 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6961 struct z_candidate *w = 0, *l = 0;
6963 for (i = 0; i < len; ++i)
6965 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6966 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6967 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6968 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6971 winner = 1, w = cand1, l = cand2;
6973 winner = -1, w = cand2, l = cand1;
6978 pedwarn (input_location, 0,
6979 "ISO C++ says that these are ambiguous, even "
6980 "though the worst conversion for the first is better than "
6981 "the worst conversion for the second:");
6982 print_z_candidate (_("candidate 1:"), w);
6983 print_z_candidate (_("candidate 2:"), l);
6991 gcc_assert (!winner);
6995 /* Given a list of candidates for overloading, find the best one, if any.
6996 This algorithm has a worst case of O(2n) (winner is last), and a best
6997 case of O(n/2) (totally ambiguous); much better than a sorting
7000 static struct z_candidate *
7001 tourney (struct z_candidate *candidates)
7003 struct z_candidate *champ = candidates, *challenger;
7005 int champ_compared_to_predecessor = 0;
7007 /* Walk through the list once, comparing each current champ to the next
7008 candidate, knocking out a candidate or two with each comparison. */
7010 for (challenger = champ->next; challenger; )
7012 fate = joust (champ, challenger, 0);
7014 challenger = challenger->next;
7019 champ = challenger->next;
7022 champ_compared_to_predecessor = 0;
7027 champ_compared_to_predecessor = 1;
7030 challenger = champ->next;
7034 /* Make sure the champ is better than all the candidates it hasn't yet
7035 been compared to. */
7037 for (challenger = candidates;
7039 && !(champ_compared_to_predecessor && challenger->next == champ);
7040 challenger = challenger->next)
7042 fate = joust (champ, challenger, 0);
7050 /* Returns nonzero if things of type FROM can be converted to TO. */
7053 can_convert (tree to, tree from)
7055 return can_convert_arg (to, from, NULL_TREE, LOOKUP_NORMAL);
7058 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7061 can_convert_arg (tree to, tree from, tree arg, int flags)
7067 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7068 p = conversion_obstack_alloc (0);
7070 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
7072 ok_p = (t && !t->bad_p);
7074 /* Free all the conversions we allocated. */
7075 obstack_free (&conversion_obstack, p);
7080 /* Like can_convert_arg, but allows dubious conversions as well. */
7083 can_convert_arg_bad (tree to, tree from, tree arg)
7088 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7089 p = conversion_obstack_alloc (0);
7090 /* Try to perform the conversion. */
7091 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
7093 /* Free all the conversions we allocated. */
7094 obstack_free (&conversion_obstack, p);
7099 /* Convert EXPR to TYPE. Return the converted expression.
7101 Note that we allow bad conversions here because by the time we get to
7102 this point we are committed to doing the conversion. If we end up
7103 doing a bad conversion, convert_like will complain. */
7106 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
7111 if (error_operand_p (expr))
7112 return error_mark_node;
7114 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7115 p = conversion_obstack_alloc (0);
7117 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
7122 if (complain & tf_error)
7123 error ("could not convert %qE to %qT", expr, type);
7124 expr = error_mark_node;
7126 else if (processing_template_decl)
7128 /* In a template, we are only concerned about determining the
7129 type of non-dependent expressions, so we do not have to
7130 perform the actual conversion. */
7131 if (TREE_TYPE (expr) != type)
7132 expr = build_nop (type, expr);
7135 expr = convert_like (conv, expr, complain);
7137 /* Free all the conversions we allocated. */
7138 obstack_free (&conversion_obstack, p);
7143 /* Convert EXPR to TYPE (as a direct-initialization) if that is
7144 permitted. If the conversion is valid, the converted expression is
7145 returned. Otherwise, NULL_TREE is returned, except in the case
7146 that TYPE is a class type; in that case, an error is issued. If
7147 C_CAST_P is true, then this direction initialization is taking
7148 place as part of a static_cast being attempted as part of a C-style
7152 perform_direct_initialization_if_possible (tree type,
7155 tsubst_flags_t complain)
7160 if (type == error_mark_node || error_operand_p (expr))
7161 return error_mark_node;
7164 If the destination type is a (possibly cv-qualified) class type:
7166 -- If the initialization is direct-initialization ...,
7167 constructors are considered. ... If no constructor applies, or
7168 the overload resolution is ambiguous, the initialization is
7170 if (CLASS_TYPE_P (type))
7172 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
7173 build_tree_list (NULL_TREE, expr),
7174 type, LOOKUP_NORMAL, complain);
7175 return build_cplus_new (type, expr);
7178 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7179 p = conversion_obstack_alloc (0);
7181 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
7184 if (!conv || conv->bad_p)
7187 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
7188 /*issue_conversion_warnings=*/false,
7190 tf_warning_or_error);
7192 /* Free all the conversions we allocated. */
7193 obstack_free (&conversion_obstack, p);
7198 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
7199 is being bound to a temporary. Create and return a new VAR_DECL
7200 with the indicated TYPE; this variable will store the value to
7201 which the reference is bound. */
7204 make_temporary_var_for_ref_to_temp (tree decl, tree type)
7208 /* Create the variable. */
7209 var = create_temporary_var (type);
7211 /* Register the variable. */
7212 if (TREE_STATIC (decl))
7214 /* Namespace-scope or local static; give it a mangled name. */
7217 TREE_STATIC (var) = 1;
7218 name = mangle_ref_init_variable (decl);
7219 DECL_NAME (var) = name;
7220 SET_DECL_ASSEMBLER_NAME (var, name);
7221 var = pushdecl_top_level (var);
7224 /* Create a new cleanup level if necessary. */
7225 maybe_push_cleanup_level (type);
7230 /* EXPR is the initializer for a variable DECL of reference or
7231 std::initializer_list type. Create, push and return a new VAR_DECL
7232 for the initializer so that it will live as long as DECL. Any
7233 cleanup for the new variable is returned through CLEANUP, and the
7234 code to initialize the new variable is returned through INITP. */
7237 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp)
7243 /* Create the temporary variable. */
7244 type = TREE_TYPE (expr);
7245 var = make_temporary_var_for_ref_to_temp (decl, type);
7246 layout_decl (var, 0);
7247 /* If the rvalue is the result of a function call it will be
7248 a TARGET_EXPR. If it is some other construct (such as a
7249 member access expression where the underlying object is
7250 itself the result of a function call), turn it into a
7251 TARGET_EXPR here. It is important that EXPR be a
7252 TARGET_EXPR below since otherwise the INIT_EXPR will
7253 attempt to make a bitwise copy of EXPR to initialize
7255 if (TREE_CODE (expr) != TARGET_EXPR)
7256 expr = get_target_expr (expr);
7257 /* Create the INIT_EXPR that will initialize the temporary
7259 init = build2 (INIT_EXPR, type, var, expr);
7260 if (at_function_scope_p ())
7262 add_decl_expr (var);
7264 if (TREE_STATIC (var))
7265 init = add_stmt_to_compound (init, register_dtor_fn (var));
7267 *cleanup = cxx_maybe_build_cleanup (var);
7269 /* We must be careful to destroy the temporary only
7270 after its initialization has taken place. If the
7271 initialization throws an exception, then the
7272 destructor should not be run. We cannot simply
7273 transform INIT into something like:
7275 (INIT, ({ CLEANUP_STMT; }))
7277 because emit_local_var always treats the
7278 initializer as a full-expression. Thus, the
7279 destructor would run too early; it would run at the
7280 end of initializing the reference variable, rather
7281 than at the end of the block enclosing the
7284 The solution is to pass back a cleanup expression
7285 which the caller is responsible for attaching to
7286 the statement tree. */
7290 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
7291 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
7292 static_aggregates = tree_cons (NULL_TREE, var,
7300 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
7301 initializing a variable of that TYPE. If DECL is non-NULL, it is
7302 the VAR_DECL being initialized with the EXPR. (In that case, the
7303 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
7304 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
7305 return, if *CLEANUP is no longer NULL, it will be an expression
7306 that should be pushed as a cleanup after the returned expression
7307 is used to initialize DECL.
7309 Return the converted expression. */
7312 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
7317 if (type == error_mark_node || error_operand_p (expr))
7318 return error_mark_node;
7320 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7321 p = conversion_obstack_alloc (0);
7323 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
7325 if (!conv || conv->bad_p)
7327 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
7328 && !TYPE_REF_IS_RVALUE (type)
7329 && !real_lvalue_p (expr))
7330 error ("invalid initialization of non-const reference of "
7331 "type %qT from a temporary of type %qT",
7332 type, TREE_TYPE (expr));
7334 error ("invalid initialization of reference of type "
7335 "%qT from expression of type %qT", type,
7337 return error_mark_node;
7340 /* If DECL is non-NULL, then this special rule applies:
7344 The temporary to which the reference is bound or the temporary
7345 that is the complete object to which the reference is bound
7346 persists for the lifetime of the reference.
7348 The temporaries created during the evaluation of the expression
7349 initializing the reference, except the temporary to which the
7350 reference is bound, are destroyed at the end of the
7351 full-expression in which they are created.
7353 In that case, we store the converted expression into a new
7354 VAR_DECL in a new scope.
7356 However, we want to be careful not to create temporaries when
7357 they are not required. For example, given:
7360 struct D : public B {};
7364 there is no need to copy the return value from "f"; we can just
7365 extend its lifetime. Similarly, given:
7368 struct T { operator S(); };
7372 we can extend the lifetime of the return value of the conversion
7374 gcc_assert (conv->kind == ck_ref_bind);
7378 tree base_conv_type;
7380 /* Skip over the REF_BIND. */
7381 conv = conv->u.next;
7382 /* If the next conversion is a BASE_CONV, skip that too -- but
7383 remember that the conversion was required. */
7384 if (conv->kind == ck_base)
7386 base_conv_type = conv->type;
7387 conv = conv->u.next;
7390 base_conv_type = NULL_TREE;
7391 /* Perform the remainder of the conversion. */
7392 expr = convert_like_real (conv, expr,
7393 /*fn=*/NULL_TREE, /*argnum=*/0,
7395 /*issue_conversion_warnings=*/true,
7397 tf_warning_or_error);
7398 if (error_operand_p (expr))
7399 expr = error_mark_node;
7402 if (!lvalue_or_rvalue_with_address_p (expr))
7405 var = set_up_extended_ref_temp (decl, expr, cleanup, &init);
7406 /* Use its address to initialize the reference variable. */
7407 expr = build_address (var);
7409 expr = convert_to_base (expr,
7410 build_pointer_type (base_conv_type),
7411 /*check_access=*/true,
7413 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
7416 /* Take the address of EXPR. */
7417 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, tf_warning_or_error);
7418 /* If a BASE_CONV was required, perform it now. */
7420 expr = (perform_implicit_conversion
7421 (build_pointer_type (base_conv_type), expr,
7422 tf_warning_or_error));
7423 expr = build_nop (type, expr);
7427 /* Perform the conversion. */
7428 expr = convert_like (conv, expr, tf_warning_or_error);
7430 /* Free all the conversions we allocated. */
7431 obstack_free (&conversion_obstack, p);
7436 /* Returns true iff TYPE is some variant of std::initializer_list. */
7439 is_std_init_list (tree type)
7441 return (CLASS_TYPE_P (type)
7442 && CP_TYPE_CONTEXT (type) == std_node
7443 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
7446 /* Returns true iff DECL is a list constructor: i.e. a constructor which
7447 will accept an argument list of a single std::initializer_list<T>. */
7450 is_list_ctor (tree decl)
7452 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
7455 if (!args || args == void_list_node)
7458 arg = non_reference (TREE_VALUE (args));
7459 if (!is_std_init_list (arg))
7462 args = TREE_CHAIN (args);
7464 if (args && args != void_list_node && !TREE_PURPOSE (args))
7465 /* There are more non-defaulted parms. */
7471 #include "gt-cp-call.h"