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 = cp_build_qualified_type (tbase, cp_type_quals (fbase));
891 from = build_method_type_directly (from,
893 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
894 from = build_ptrmemfunc_type (build_pointer_type (from));
895 conv = build_conv (ck_pmem, from, conv);
898 else if (tcode == BOOLEAN_TYPE)
902 An rvalue of arithmetic, unscoped enumeration, pointer, or
903 pointer to member type can be converted to an rvalue of type
905 if (ARITHMETIC_TYPE_P (from)
906 || UNSCOPED_ENUM_P (from)
907 || fcode == POINTER_TYPE
908 || TYPE_PTR_TO_MEMBER_P (from))
910 conv = build_conv (ck_std, to, conv);
911 if (fcode == POINTER_TYPE
912 || TYPE_PTRMEM_P (from)
913 || (TYPE_PTRMEMFUNC_P (from)
914 && conv->rank < cr_pbool))
915 conv->rank = cr_pbool;
921 /* We don't check for ENUMERAL_TYPE here because there are no standard
922 conversions to enum type. */
923 /* As an extension, allow conversion to complex type. */
924 else if (ARITHMETIC_TYPE_P (to))
926 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
927 || SCOPED_ENUM_P (from))
929 conv = build_conv (ck_std, to, conv);
931 /* Give this a better rank if it's a promotion. */
932 if (same_type_p (to, type_promotes_to (from))
933 && conv->u.next->rank <= cr_promotion)
934 conv->rank = cr_promotion;
936 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
937 && vector_types_convertible_p (from, to, false))
938 return build_conv (ck_std, to, conv);
939 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
940 && is_properly_derived_from (from, to))
942 if (conv->kind == ck_rvalue)
944 conv = build_conv (ck_base, to, conv);
945 /* The derived-to-base conversion indicates the initialization
946 of a parameter with base type from an object of a derived
947 type. A temporary object is created to hold the result of
948 the conversion unless we're binding directly to a reference. */
949 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
954 if (flags & LOOKUP_NO_NARROWING)
955 conv->check_narrowing = true;
960 /* Returns nonzero if T1 is reference-related to T2. */
963 reference_related_p (tree t1, tree t2)
965 t1 = TYPE_MAIN_VARIANT (t1);
966 t2 = TYPE_MAIN_VARIANT (t2);
970 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
971 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
973 return (same_type_p (t1, t2)
974 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
975 && DERIVED_FROM_P (t1, t2)));
978 /* Returns nonzero if T1 is reference-compatible with T2. */
981 reference_compatible_p (tree t1, tree t2)
985 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
986 reference-related to T2 and cv1 is the same cv-qualification as,
987 or greater cv-qualification than, cv2. */
988 return (reference_related_p (t1, t2)
989 && at_least_as_qualified_p (t1, t2));
992 /* Determine whether or not the EXPR (of class type S) can be
993 converted to T as in [over.match.ref]. */
996 convert_class_to_reference (tree reference_type, tree s, tree expr)
1002 struct z_candidate *candidates;
1003 struct z_candidate *cand;
1006 conversions = lookup_conversions (s);
1012 Assuming that "cv1 T" is the underlying type of the reference
1013 being initialized, and "cv S" is the type of the initializer
1014 expression, with S a class type, the candidate functions are
1015 selected as follows:
1017 --The conversion functions of S and its base classes are
1018 considered. Those that are not hidden within S and yield type
1019 "reference to cv2 T2", where "cv1 T" is reference-compatible
1020 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1022 The argument list has one argument, which is the initializer
1027 /* Conceptually, we should take the address of EXPR and put it in
1028 the argument list. Unfortunately, however, that can result in
1029 error messages, which we should not issue now because we are just
1030 trying to find a conversion operator. Therefore, we use NULL,
1031 cast to the appropriate type. */
1032 arglist = build_int_cst (build_pointer_type (s), 0);
1033 arglist = build_tree_list (NULL_TREE, arglist);
1035 t = TREE_TYPE (reference_type);
1039 tree fns = TREE_VALUE (conversions);
1041 for (; fns; fns = OVL_NEXT (fns))
1043 tree f = OVL_CURRENT (fns);
1044 tree t2 = TREE_TYPE (TREE_TYPE (f));
1048 /* If this is a template function, try to get an exact
1050 if (TREE_CODE (f) == TEMPLATE_DECL)
1052 cand = add_template_candidate (&candidates,
1058 TREE_PURPOSE (conversions),
1064 /* Now, see if the conversion function really returns
1065 an lvalue of the appropriate type. From the
1066 point of view of unification, simply returning an
1067 rvalue of the right type is good enough. */
1069 t2 = TREE_TYPE (TREE_TYPE (f));
1070 if (TREE_CODE (t2) != REFERENCE_TYPE
1071 || !reference_compatible_p (t, TREE_TYPE (t2)))
1073 candidates = candidates->next;
1078 else if (TREE_CODE (t2) == REFERENCE_TYPE
1079 && reference_compatible_p (t, TREE_TYPE (t2)))
1080 cand = add_function_candidate (&candidates, f, s, arglist,
1082 TREE_PURPOSE (conversions),
1087 conversion *identity_conv;
1088 /* Build a standard conversion sequence indicating the
1089 binding from the reference type returned by the
1090 function to the desired REFERENCE_TYPE. */
1092 = build_identity_conv (TREE_TYPE (TREE_TYPE
1093 (TREE_TYPE (cand->fn))),
1096 = (direct_reference_binding
1097 (reference_type, identity_conv));
1098 cand->second_conv->rvaluedness_matches_p
1099 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1100 == TYPE_REF_IS_RVALUE (reference_type);
1101 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1104 conversions = TREE_CHAIN (conversions);
1107 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1108 /* If none of the conversion functions worked out, let our caller
1113 cand = tourney (candidates);
1117 /* Now that we know that this is the function we're going to use fix
1118 the dummy first argument. */
1119 cand->args = tree_cons (NULL_TREE,
1121 TREE_CHAIN (cand->args));
1123 /* Build a user-defined conversion sequence representing the
1125 conv = build_conv (ck_user,
1126 TREE_TYPE (TREE_TYPE (cand->fn)),
1127 build_identity_conv (TREE_TYPE (expr), expr));
1130 /* Merge it with the standard conversion sequence from the
1131 conversion function's return type to the desired type. */
1132 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1134 if (cand->viable == -1)
1137 return cand->second_conv;
1140 /* A reference of the indicated TYPE is being bound directly to the
1141 expression represented by the implicit conversion sequence CONV.
1142 Return a conversion sequence for this binding. */
1145 direct_reference_binding (tree type, conversion *conv)
1149 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1150 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1152 t = TREE_TYPE (type);
1156 When a parameter of reference type binds directly
1157 (_dcl.init.ref_) to an argument expression, the implicit
1158 conversion sequence is the identity conversion, unless the
1159 argument expression has a type that is a derived class of the
1160 parameter type, in which case the implicit conversion sequence is
1161 a derived-to-base Conversion.
1163 If the parameter binds directly to the result of applying a
1164 conversion function to the argument expression, the implicit
1165 conversion sequence is a user-defined conversion sequence
1166 (_over.ics.user_), with the second standard conversion sequence
1167 either an identity conversion or, if the conversion function
1168 returns an entity of a type that is a derived class of the
1169 parameter type, a derived-to-base conversion. */
1170 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1172 /* Represent the derived-to-base conversion. */
1173 conv = build_conv (ck_base, t, conv);
1174 /* We will actually be binding to the base-class subobject in
1175 the derived class, so we mark this conversion appropriately.
1176 That way, convert_like knows not to generate a temporary. */
1177 conv->need_temporary_p = false;
1179 return build_conv (ck_ref_bind, type, conv);
1182 /* Returns the conversion path from type FROM to reference type TO for
1183 purposes of reference binding. For lvalue binding, either pass a
1184 reference type to FROM or an lvalue expression to EXPR. If the
1185 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1186 the conversion returned. If C_CAST_P is true, this
1187 conversion is coming from a C-style cast. */
1190 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1192 conversion *conv = NULL;
1193 tree to = TREE_TYPE (rto);
1198 cp_lvalue_kind lvalue_p = clk_none;
1200 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1202 expr = instantiate_type (to, expr, tf_none);
1203 if (expr == error_mark_node)
1205 from = TREE_TYPE (expr);
1208 if (TREE_CODE (from) == REFERENCE_TYPE)
1210 /* Anything with reference type is an lvalue. */
1211 lvalue_p = clk_ordinary;
1212 from = TREE_TYPE (from);
1215 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1217 maybe_warn_cpp0x ("extended initializer lists");
1218 conv = implicit_conversion (to, from, expr, c_cast_p,
1220 if (!CLASS_TYPE_P (to)
1221 && CONSTRUCTOR_NELTS (expr) == 1)
1223 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1224 from = TREE_TYPE (expr);
1228 if (lvalue_p == clk_none && expr)
1229 lvalue_p = real_lvalue_p (expr);
1232 if ((lvalue_p & clk_bitfield) != 0)
1233 tfrom = unlowered_expr_type (expr);
1235 /* Figure out whether or not the types are reference-related and
1236 reference compatible. We have do do this after stripping
1237 references from FROM. */
1238 related_p = reference_related_p (to, tfrom);
1239 /* If this is a C cast, first convert to an appropriately qualified
1240 type, so that we can later do a const_cast to the desired type. */
1241 if (related_p && c_cast_p
1242 && !at_least_as_qualified_p (to, tfrom))
1243 to = build_qualified_type (to, cp_type_quals (tfrom));
1244 compatible_p = reference_compatible_p (to, tfrom);
1246 /* Directly bind reference when target expression's type is compatible with
1247 the reference and expression is an lvalue. In DR391, the wording in
1248 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1249 const and rvalue references to rvalues of compatible class type. */
1252 || (!(flags & LOOKUP_NO_TEMP_BIND)
1253 && (CP_TYPE_CONST_NON_VOLATILE_P(to) || TYPE_REF_IS_RVALUE (rto))
1254 && CLASS_TYPE_P (from))))
1258 If the initializer expression
1260 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1261 is reference-compatible with "cv2 T2,"
1263 the reference is bound directly to the initializer expression
1267 If the initializer expression is an rvalue, with T2 a class type,
1268 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1269 is bound to the object represented by the rvalue or to a sub-object
1270 within that object. */
1272 conv = build_identity_conv (tfrom, expr);
1273 conv = direct_reference_binding (rto, conv);
1275 if (flags & LOOKUP_PREFER_RVALUE)
1276 /* The top-level caller requested that we pretend that the lvalue
1277 be treated as an rvalue. */
1278 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1280 conv->rvaluedness_matches_p
1281 = (TYPE_REF_IS_RVALUE (rto) == !lvalue_p);
1283 if ((lvalue_p & clk_bitfield) != 0
1284 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1285 /* For the purposes of overload resolution, we ignore the fact
1286 this expression is a bitfield or packed field. (In particular,
1287 [over.ics.ref] says specifically that a function with a
1288 non-const reference parameter is viable even if the
1289 argument is a bitfield.)
1291 However, when we actually call the function we must create
1292 a temporary to which to bind the reference. If the
1293 reference is volatile, or isn't const, then we cannot make
1294 a temporary, so we just issue an error when the conversion
1296 conv->need_temporary_p = true;
1300 /* [class.conv.fct] A conversion function is never used to convert a
1301 (possibly cv-qualified) object to the (possibly cv-qualified) same
1302 object type (or a reference to it), to a (possibly cv-qualified) base
1303 class of that type (or a reference to it).... */
1304 else if (CLASS_TYPE_P (from) && !related_p
1305 && !(flags & LOOKUP_NO_CONVERSION))
1309 If the initializer expression
1311 -- has a class type (i.e., T2 is a class type) can be
1312 implicitly converted to an lvalue of type "cv3 T3," where
1313 "cv1 T1" is reference-compatible with "cv3 T3". (this
1314 conversion is selected by enumerating the applicable
1315 conversion functions (_over.match.ref_) and choosing the
1316 best one through overload resolution. (_over.match_).
1318 the reference is bound to the lvalue result of the conversion
1319 in the second case. */
1320 conv = convert_class_to_reference (rto, from, expr);
1325 /* From this point on, we conceptually need temporaries, even if we
1326 elide them. Only the cases above are "direct bindings". */
1327 if (flags & LOOKUP_NO_TEMP_BIND)
1332 When a parameter of reference type is not bound directly to an
1333 argument expression, the conversion sequence is the one required
1334 to convert the argument expression to the underlying type of the
1335 reference according to _over.best.ics_. Conceptually, this
1336 conversion sequence corresponds to copy-initializing a temporary
1337 of the underlying type with the argument expression. Any
1338 difference in top-level cv-qualification is subsumed by the
1339 initialization itself and does not constitute a conversion. */
1343 Otherwise, the reference shall be to a non-volatile const type.
1345 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1346 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1351 Otherwise, a temporary of type "cv1 T1" is created and
1352 initialized from the initializer expression using the rules for a
1353 non-reference copy initialization. If T1 is reference-related to
1354 T2, cv1 must be the same cv-qualification as, or greater
1355 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1356 if (related_p && !at_least_as_qualified_p (to, from))
1359 /* We're generating a temporary now, but don't bind any more in the
1360 conversion (specifically, don't slice the temporary returned by a
1361 conversion operator). */
1362 flags |= LOOKUP_NO_TEMP_BIND;
1365 conv = implicit_conversion (to, from, expr, c_cast_p,
1370 conv = build_conv (ck_ref_bind, rto, conv);
1371 /* This reference binding, unlike those above, requires the
1372 creation of a temporary. */
1373 conv->need_temporary_p = true;
1374 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1379 /* Returns the implicit conversion sequence (see [over.ics]) from type
1380 FROM to type TO. The optional expression EXPR may affect the
1381 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1382 true, this conversion is coming from a C-style cast. */
1385 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1390 if (from == error_mark_node || to == error_mark_node
1391 || expr == error_mark_node)
1394 if (TREE_CODE (to) == REFERENCE_TYPE)
1395 conv = reference_binding (to, from, expr, c_cast_p, flags);
1397 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1402 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1404 if (is_std_init_list (to))
1405 return build_list_conv (to, expr, flags);
1407 /* Allow conversion from an initializer-list with one element to a
1409 if (SCALAR_TYPE_P (to))
1411 int nelts = CONSTRUCTOR_NELTS (expr);
1415 elt = integer_zero_node;
1416 else if (nelts == 1)
1417 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1419 elt = error_mark_node;
1421 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1425 conv->check_narrowing = true;
1426 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1427 /* Too many levels of braces, i.e. '{{1}}'. */
1434 if (expr != NULL_TREE
1435 && (MAYBE_CLASS_TYPE_P (from)
1436 || MAYBE_CLASS_TYPE_P (to))
1437 && (flags & LOOKUP_NO_CONVERSION) == 0)
1439 struct z_candidate *cand;
1440 int convflags = ((flags & LOOKUP_NO_TEMP_BIND)
1441 |LOOKUP_ONLYCONVERTING);
1443 if (CLASS_TYPE_P (to)
1444 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1445 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1446 return build_aggr_conv (to, expr, flags);
1448 cand = build_user_type_conversion_1 (to, expr, convflags);
1450 conv = cand->second_conv;
1452 /* We used to try to bind a reference to a temporary here, but that
1453 is now handled after the recursive call to this function at the end
1454 of reference_binding. */
1461 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1464 static struct z_candidate *
1465 add_candidate (struct z_candidate **candidates,
1467 size_t num_convs, conversion **convs,
1468 tree access_path, tree conversion_path,
1471 struct z_candidate *cand = (struct z_candidate *)
1472 conversion_obstack_alloc (sizeof (struct z_candidate));
1476 cand->convs = convs;
1477 cand->num_convs = num_convs;
1478 cand->access_path = access_path;
1479 cand->conversion_path = conversion_path;
1480 cand->viable = viable;
1481 cand->next = *candidates;
1487 /* Create an overload candidate for the function or method FN called with
1488 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1489 to implicit_conversion.
1491 CTYPE, if non-NULL, is the type we want to pretend this function
1492 comes from for purposes of overload resolution. */
1494 static struct z_candidate *
1495 add_function_candidate (struct z_candidate **candidates,
1496 tree fn, tree ctype, tree arglist,
1497 tree access_path, tree conversion_path,
1500 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1503 tree parmnode, argnode;
1507 /* At this point we should not see any functions which haven't been
1508 explicitly declared, except for friend functions which will have
1509 been found using argument dependent lookup. */
1510 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1512 /* The `this', `in_chrg' and VTT arguments to constructors are not
1513 considered in overload resolution. */
1514 if (DECL_CONSTRUCTOR_P (fn))
1516 parmlist = skip_artificial_parms_for (fn, parmlist);
1517 orig_arglist = arglist;
1518 arglist = skip_artificial_parms_for (fn, arglist);
1521 orig_arglist = arglist;
1523 len = list_length (arglist);
1524 convs = alloc_conversions (len);
1526 /* 13.3.2 - Viable functions [over.match.viable]
1527 First, to be a viable function, a candidate function shall have enough
1528 parameters to agree in number with the arguments in the list.
1530 We need to check this first; otherwise, checking the ICSes might cause
1531 us to produce an ill-formed template instantiation. */
1533 parmnode = parmlist;
1534 for (i = 0; i < len; ++i)
1536 if (parmnode == NULL_TREE || parmnode == void_list_node)
1538 parmnode = TREE_CHAIN (parmnode);
1541 if (i < len && parmnode)
1544 /* Make sure there are default args for the rest of the parms. */
1545 else if (!sufficient_parms_p (parmnode))
1551 /* Second, for F to be a viable function, there shall exist for each
1552 argument an implicit conversion sequence that converts that argument
1553 to the corresponding parameter of F. */
1555 parmnode = parmlist;
1558 for (i = 0; i < len; ++i)
1560 tree arg = TREE_VALUE (argnode);
1561 tree argtype = lvalue_type (arg);
1565 if (parmnode == void_list_node)
1568 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1569 && ! DECL_CONSTRUCTOR_P (fn));
1573 tree parmtype = TREE_VALUE (parmnode);
1576 /* The type of the implicit object parameter ('this') for
1577 overload resolution is not always the same as for the
1578 function itself; conversion functions are considered to
1579 be members of the class being converted, and functions
1580 introduced by a using-declaration are considered to be
1581 members of the class that uses them.
1583 Since build_over_call ignores the ICS for the `this'
1584 parameter, we can just change the parm type. */
1585 if (ctype && is_this)
1588 = build_qualified_type (ctype,
1589 TYPE_QUALS (TREE_TYPE (parmtype)));
1590 parmtype = build_pointer_type (parmtype);
1593 if ((flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1594 && ctype && i == 0 && DECL_COPY_CONSTRUCTOR_P (fn))
1595 lflags |= LOOKUP_NO_CONVERSION;
1597 t = implicit_conversion (parmtype, argtype, arg,
1598 /*c_cast_p=*/false, lflags);
1602 t = build_identity_conv (argtype, arg);
1603 t->ellipsis_p = true;
1620 parmnode = TREE_CHAIN (parmnode);
1621 argnode = TREE_CHAIN (argnode);
1625 return add_candidate (candidates, fn, orig_arglist, len, convs,
1626 access_path, conversion_path, viable);
1629 /* Create an overload candidate for the conversion function FN which will
1630 be invoked for expression OBJ, producing a pointer-to-function which
1631 will in turn be called with the argument list ARGLIST, and add it to
1632 CANDIDATES. FLAGS is passed on to implicit_conversion.
1634 Actually, we don't really care about FN; we care about the type it
1635 converts to. There may be multiple conversion functions that will
1636 convert to that type, and we rely on build_user_type_conversion_1 to
1637 choose the best one; so when we create our candidate, we record the type
1638 instead of the function. */
1640 static struct z_candidate *
1641 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1642 tree arglist, tree access_path, tree conversion_path)
1644 tree totype = TREE_TYPE (TREE_TYPE (fn));
1645 int i, len, viable, flags;
1646 tree parmlist, parmnode, argnode;
1649 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1650 parmlist = TREE_TYPE (parmlist);
1651 parmlist = TYPE_ARG_TYPES (parmlist);
1653 len = list_length (arglist) + 1;
1654 convs = alloc_conversions (len);
1655 parmnode = parmlist;
1658 flags = LOOKUP_NORMAL;
1660 /* Don't bother looking up the same type twice. */
1661 if (*candidates && (*candidates)->fn == totype)
1664 for (i = 0; i < len; ++i)
1666 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1667 tree argtype = lvalue_type (arg);
1671 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1673 else if (parmnode == void_list_node)
1676 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1677 /*c_cast_p=*/false, flags);
1680 t = build_identity_conv (argtype, arg);
1681 t->ellipsis_p = true;
1695 parmnode = TREE_CHAIN (parmnode);
1696 argnode = TREE_CHAIN (argnode);
1702 if (!sufficient_parms_p (parmnode))
1705 return add_candidate (candidates, totype, arglist, len, convs,
1706 access_path, conversion_path, viable);
1710 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1711 tree type1, tree type2, tree *args, tree *argtypes,
1723 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1724 convs = alloc_conversions (num_convs);
1726 for (i = 0; i < 2; ++i)
1731 t = implicit_conversion (types[i], argtypes[i], args[i],
1732 /*c_cast_p=*/false, flags);
1736 /* We need something for printing the candidate. */
1737 t = build_identity_conv (types[i], NULL_TREE);
1744 /* For COND_EXPR we rearranged the arguments; undo that now. */
1747 convs[2] = convs[1];
1748 convs[1] = convs[0];
1749 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1750 /*c_cast_p=*/false, flags);
1757 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1759 /*access_path=*/NULL_TREE,
1760 /*conversion_path=*/NULL_TREE,
1765 is_complete (tree t)
1767 return COMPLETE_TYPE_P (complete_type (t));
1770 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1773 promoted_arithmetic_type_p (tree type)
1777 In this section, the term promoted integral type is used to refer
1778 to those integral types which are preserved by integral promotion
1779 (including e.g. int and long but excluding e.g. char).
1780 Similarly, the term promoted arithmetic type refers to promoted
1781 integral types plus floating types. */
1782 return ((INTEGRAL_TYPE_P (type)
1783 && same_type_p (type_promotes_to (type), type))
1784 || TREE_CODE (type) == REAL_TYPE);
1787 /* Create any builtin operator overload candidates for the operator in
1788 question given the converted operand types TYPE1 and TYPE2. The other
1789 args are passed through from add_builtin_candidates to
1790 build_builtin_candidate.
1792 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1793 If CODE is requires candidates operands of the same type of the kind
1794 of which TYPE1 and TYPE2 are, we add both candidates
1795 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1798 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1799 enum tree_code code2, tree fnname, tree type1,
1800 tree type2, tree *args, tree *argtypes, int flags)
1804 case POSTINCREMENT_EXPR:
1805 case POSTDECREMENT_EXPR:
1806 args[1] = integer_zero_node;
1807 type2 = integer_type_node;
1816 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1817 and VQ is either volatile or empty, there exist candidate operator
1818 functions of the form
1819 VQ T& operator++(VQ T&);
1820 T operator++(VQ T&, int);
1821 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1822 type other than bool, and VQ is either volatile or empty, there exist
1823 candidate operator functions of the form
1824 VQ T& operator--(VQ T&);
1825 T operator--(VQ T&, int);
1826 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1827 complete object type, and VQ is either volatile or empty, there exist
1828 candidate operator functions of the form
1829 T*VQ& operator++(T*VQ&);
1830 T*VQ& operator--(T*VQ&);
1831 T* operator++(T*VQ&, int);
1832 T* operator--(T*VQ&, int); */
1834 case POSTDECREMENT_EXPR:
1835 case PREDECREMENT_EXPR:
1836 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1838 case POSTINCREMENT_EXPR:
1839 case PREINCREMENT_EXPR:
1840 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1842 type1 = build_reference_type (type1);
1847 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1848 exist candidate operator functions of the form
1852 8 For every function type T, there exist candidate operator functions of
1854 T& operator*(T*); */
1857 if (TREE_CODE (type1) == POINTER_TYPE
1858 && (TYPE_PTROB_P (type1)
1859 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1863 /* 9 For every type T, there exist candidate operator functions of the form
1866 10For every promoted arithmetic type T, there exist candidate operator
1867 functions of the form
1871 case UNARY_PLUS_EXPR: /* unary + */
1872 if (TREE_CODE (type1) == POINTER_TYPE)
1875 if (ARITHMETIC_TYPE_P (type1))
1879 /* 11For every promoted integral type T, there exist candidate operator
1880 functions of the form
1884 if (INTEGRAL_TYPE_P (type1))
1888 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1889 is the same type as C2 or is a derived class of C2, T is a complete
1890 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1891 there exist candidate operator functions of the form
1892 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1893 where CV12 is the union of CV1 and CV2. */
1896 if (TREE_CODE (type1) == POINTER_TYPE
1897 && TYPE_PTR_TO_MEMBER_P (type2))
1899 tree c1 = TREE_TYPE (type1);
1900 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1902 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
1903 && (TYPE_PTRMEMFUNC_P (type2)
1904 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1909 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1910 didate operator functions of the form
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 bool operator!=(L, R);
1921 where LR is the result of the usual arithmetic conversions between
1924 14For every pair of types T and I, where T is a cv-qualified or cv-
1925 unqualified complete object type and I is a promoted integral type,
1926 there exist candidate operator functions of the form
1927 T* operator+(T*, I);
1928 T& operator[](T*, I);
1929 T* operator-(T*, I);
1930 T* operator+(I, T*);
1931 T& operator[](I, T*);
1933 15For every T, where T is a pointer to complete object type, there exist
1934 candidate operator functions of the form112)
1935 ptrdiff_t operator-(T, T);
1937 16For every pointer or enumeration type T, there exist candidate operator
1938 functions of the form
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);
1944 bool operator!=(T, T);
1946 17For every pointer to member type T, there exist candidate operator
1947 functions of the form
1948 bool operator==(T, T);
1949 bool operator!=(T, T); */
1952 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1954 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1956 type2 = ptrdiff_type_node;
1960 case TRUNC_DIV_EXPR:
1961 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1967 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1968 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1970 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1975 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1987 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1989 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1991 if (TREE_CODE (type1) == ENUMERAL_TYPE
1992 && TREE_CODE (type2) == ENUMERAL_TYPE)
1994 if (TYPE_PTR_P (type1)
1995 && null_ptr_cst_p (args[1])
1996 && !uses_template_parms (type1))
2001 if (null_ptr_cst_p (args[0])
2002 && TYPE_PTR_P (type2)
2003 && !uses_template_parms (type2))
2011 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2014 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
2016 type1 = ptrdiff_type_node;
2019 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
2021 type2 = ptrdiff_type_node;
2026 /* 18For every pair of promoted integral types L and R, there exist candi-
2027 date operator functions of the form
2034 where LR is the result of the usual arithmetic conversions between
2037 case TRUNC_MOD_EXPR:
2043 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
2047 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2048 type, VQ is either volatile or empty, and R is a promoted arithmetic
2049 type, there exist candidate operator functions of the form
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);
2054 VQ L& operator-=(VQ L&, R);
2056 20For every pair T, VQ), where T is any type and VQ is either volatile
2057 or empty, there exist candidate operator functions of the form
2058 T*VQ& operator=(T*VQ&, T*);
2060 21For every pair T, VQ), where T is a pointer to member type and VQ is
2061 either volatile or empty, there exist candidate operator functions of
2063 VQ T& operator=(VQ T&, T);
2065 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2066 unqualified complete object type, VQ is either volatile or empty, and
2067 I is a promoted integral type, there exist candidate operator func-
2069 T*VQ& operator+=(T*VQ&, I);
2070 T*VQ& operator-=(T*VQ&, I);
2072 23For every triple L, VQ, R), where L is an integral or enumeration
2073 type, VQ is either volatile or empty, and R is a promoted integral
2074 type, there exist candidate operator functions of the form
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);
2081 VQ L& operator|=(VQ L&, R); */
2088 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
2090 type2 = ptrdiff_type_node;
2094 case TRUNC_DIV_EXPR:
2095 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2099 case TRUNC_MOD_EXPR:
2105 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
2110 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2112 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2113 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2114 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2115 || ((TYPE_PTRMEMFUNC_P (type1)
2116 || TREE_CODE (type1) == POINTER_TYPE)
2117 && null_ptr_cst_p (args[1])))
2127 type1 = build_reference_type (type1);
2133 For every pair of promoted arithmetic types L and R, there
2134 exist candidate operator functions of the form
2136 LR operator?(bool, L, R);
2138 where LR is the result of the usual arithmetic conversions
2139 between types L and R.
2141 For every type T, where T is a pointer or pointer-to-member
2142 type, there exist candidate operator functions of the form T
2143 operator?(bool, T, T); */
2145 if (promoted_arithmetic_type_p (type1)
2146 && promoted_arithmetic_type_p (type2))
2150 /* Otherwise, the types should be pointers. */
2151 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2152 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2155 /* We don't check that the two types are the same; the logic
2156 below will actually create two candidates; one in which both
2157 parameter types are TYPE1, and one in which both parameter
2165 /* If we're dealing with two pointer types or two enumeral types,
2166 we need candidates for both of them. */
2167 if (type2 && !same_type_p (type1, type2)
2168 && TREE_CODE (type1) == TREE_CODE (type2)
2169 && (TREE_CODE (type1) == REFERENCE_TYPE
2170 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2171 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2172 || TYPE_PTRMEMFUNC_P (type1)
2173 || MAYBE_CLASS_TYPE_P (type1)
2174 || TREE_CODE (type1) == ENUMERAL_TYPE))
2176 build_builtin_candidate
2177 (candidates, fnname, type1, type1, args, argtypes, flags);
2178 build_builtin_candidate
2179 (candidates, fnname, type2, type2, args, argtypes, flags);
2183 build_builtin_candidate
2184 (candidates, fnname, type1, type2, args, argtypes, flags);
2188 type_decays_to (tree type)
2190 if (TREE_CODE (type) == ARRAY_TYPE)
2191 return build_pointer_type (TREE_TYPE (type));
2192 if (TREE_CODE (type) == FUNCTION_TYPE)
2193 return build_pointer_type (type);
2197 /* There are three conditions of builtin candidates:
2199 1) bool-taking candidates. These are the same regardless of the input.
2200 2) pointer-pair taking candidates. These are generated for each type
2201 one of the input types converts to.
2202 3) arithmetic candidates. According to the standard, we should generate
2203 all of these, but I'm trying not to...
2205 Here we generate a superset of the possible candidates for this particular
2206 case. That is a subset of the full set the standard defines, plus some
2207 other cases which the standard disallows. add_builtin_candidate will
2208 filter out the invalid set. */
2211 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2212 enum tree_code code2, tree fnname, tree *args,
2217 tree type, argtypes[3];
2218 /* TYPES[i] is the set of possible builtin-operator parameter types
2219 we will consider for the Ith argument. These are represented as
2220 a TREE_LIST; the TREE_VALUE of each node is the potential
2224 for (i = 0; i < 3; ++i)
2227 argtypes[i] = unlowered_expr_type (args[i]);
2229 argtypes[i] = NULL_TREE;
2234 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2235 and VQ is either volatile or empty, there exist candidate operator
2236 functions of the form
2237 VQ T& operator++(VQ T&); */
2239 case POSTINCREMENT_EXPR:
2240 case PREINCREMENT_EXPR:
2241 case POSTDECREMENT_EXPR:
2242 case PREDECREMENT_EXPR:
2247 /* 24There also exist candidate operator functions of the form
2248 bool operator!(bool);
2249 bool operator&&(bool, bool);
2250 bool operator||(bool, bool); */
2252 case TRUTH_NOT_EXPR:
2253 build_builtin_candidate
2254 (candidates, fnname, boolean_type_node,
2255 NULL_TREE, args, argtypes, flags);
2258 case TRUTH_ORIF_EXPR:
2259 case TRUTH_ANDIF_EXPR:
2260 build_builtin_candidate
2261 (candidates, fnname, boolean_type_node,
2262 boolean_type_node, args, argtypes, flags);
2284 types[0] = types[1] = NULL_TREE;
2286 for (i = 0; i < 2; ++i)
2290 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2294 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2297 convs = lookup_conversions (argtypes[i]);
2299 if (code == COND_EXPR)
2301 if (real_lvalue_p (args[i]))
2302 types[i] = tree_cons
2303 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2305 types[i] = tree_cons
2306 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2312 for (; convs; convs = TREE_CHAIN (convs))
2314 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2317 && (TREE_CODE (type) != REFERENCE_TYPE
2318 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2321 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2322 types[i] = tree_cons (NULL_TREE, type, types[i]);
2324 type = non_reference (type);
2325 if (i != 0 || ! ref1)
2327 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2328 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2329 types[i] = tree_cons (NULL_TREE, type, types[i]);
2330 if (INTEGRAL_TYPE_P (type))
2331 type = type_promotes_to (type);
2334 if (! value_member (type, types[i]))
2335 types[i] = tree_cons (NULL_TREE, type, types[i]);
2340 if (code == COND_EXPR && real_lvalue_p (args[i]))
2341 types[i] = tree_cons
2342 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2343 type = non_reference (argtypes[i]);
2344 if (i != 0 || ! ref1)
2346 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2347 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2348 types[i] = tree_cons (NULL_TREE, type, types[i]);
2349 if (INTEGRAL_TYPE_P (type))
2350 type = type_promotes_to (type);
2352 types[i] = tree_cons (NULL_TREE, type, types[i]);
2356 /* Run through the possible parameter types of both arguments,
2357 creating candidates with those parameter types. */
2358 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2361 for (type = types[1]; type; type = TREE_CHAIN (type))
2362 add_builtin_candidate
2363 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2364 TREE_VALUE (type), args, argtypes, flags);
2366 add_builtin_candidate
2367 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2368 NULL_TREE, args, argtypes, flags);
2373 /* If TMPL can be successfully instantiated as indicated by
2374 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2376 TMPL is the template. EXPLICIT_TARGS are any explicit template
2377 arguments. ARGLIST is the arguments provided at the call-site.
2378 The RETURN_TYPE is the desired type for conversion operators. If
2379 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2380 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2381 add_conv_candidate. */
2383 static struct z_candidate*
2384 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2385 tree ctype, tree explicit_targs, tree arglist,
2386 tree return_type, tree access_path,
2387 tree conversion_path, int flags, tree obj,
2388 unification_kind_t strict)
2390 int ntparms = DECL_NTPARMS (tmpl);
2391 tree targs = make_tree_vec (ntparms);
2392 tree args_without_in_chrg = arglist;
2393 struct z_candidate *cand;
2397 /* We don't do deduction on the in-charge parameter, the VTT
2398 parameter or 'this'. */
2399 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2400 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2402 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2403 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2404 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2405 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2407 i = fn_type_unification (tmpl, explicit_targs, targs,
2408 args_without_in_chrg,
2409 return_type, strict, flags);
2414 fn = instantiate_template (tmpl, targs, tf_none);
2415 if (fn == error_mark_node)
2420 A member function template is never instantiated to perform the
2421 copy of a class object to an object of its class type.
2423 It's a little unclear what this means; the standard explicitly
2424 does allow a template to be used to copy a class. For example,
2429 template <class T> A(const T&);
2432 void g () { A a (f ()); }
2434 the member template will be used to make the copy. The section
2435 quoted above appears in the paragraph that forbids constructors
2436 whose only parameter is (a possibly cv-qualified variant of) the
2437 class type, and a logical interpretation is that the intent was
2438 to forbid the instantiation of member templates which would then
2440 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2442 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2443 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2448 if (obj != NULL_TREE)
2449 /* Aha, this is a conversion function. */
2450 cand = add_conv_candidate (candidates, fn, obj, access_path,
2451 conversion_path, arglist);
2453 cand = add_function_candidate (candidates, fn, ctype,
2454 arglist, access_path,
2455 conversion_path, flags);
2456 if (DECL_TI_TEMPLATE (fn) != tmpl)
2457 /* This situation can occur if a member template of a template
2458 class is specialized. Then, instantiate_template might return
2459 an instantiation of the specialization, in which case the
2460 DECL_TI_TEMPLATE field will point at the original
2461 specialization. For example:
2463 template <class T> struct S { template <class U> void f(U);
2464 template <> void f(int) {}; };
2468 Here, TMPL will be template <class U> S<double>::f(U).
2469 And, instantiate template will give us the specialization
2470 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2471 for this will point at template <class T> template <> S<T>::f(int),
2472 so that we can find the definition. For the purposes of
2473 overload resolution, however, we want the original TMPL. */
2474 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2476 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2482 static struct z_candidate *
2483 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2484 tree explicit_targs, tree arglist, tree return_type,
2485 tree access_path, tree conversion_path, int flags,
2486 unification_kind_t strict)
2489 add_template_candidate_real (candidates, tmpl, ctype,
2490 explicit_targs, arglist, return_type,
2491 access_path, conversion_path,
2492 flags, NULL_TREE, strict);
2496 static struct z_candidate *
2497 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2498 tree obj, tree arglist, tree return_type,
2499 tree access_path, tree conversion_path)
2502 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2503 arglist, return_type, access_path,
2504 conversion_path, 0, obj, DEDUCE_CONV);
2507 /* The CANDS are the set of candidates that were considered for
2508 overload resolution. Return the set of viable candidates. If none
2509 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2510 is true if a candidate should be considered viable only if it is
2513 static struct z_candidate*
2514 splice_viable (struct z_candidate *cands,
2518 struct z_candidate *viable;
2519 struct z_candidate **last_viable;
2520 struct z_candidate **cand;
2523 last_viable = &viable;
2524 *any_viable_p = false;
2529 struct z_candidate *c = *cand;
2530 if (strict_p ? c->viable == 1 : c->viable)
2535 last_viable = &c->next;
2536 *any_viable_p = true;
2542 return viable ? viable : cands;
2546 any_strictly_viable (struct z_candidate *cands)
2548 for (; cands; cands = cands->next)
2549 if (cands->viable == 1)
2554 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2555 words, it is about to become the "this" pointer for a member
2556 function call. Take the address of the object. */
2559 build_this (tree obj)
2561 /* In a template, we are only concerned about the type of the
2562 expression, so we can take a shortcut. */
2563 if (processing_template_decl)
2564 return build_address (obj);
2566 return cp_build_unary_op (ADDR_EXPR, obj, 0, tf_warning_or_error);
2569 /* Returns true iff functions are equivalent. Equivalent functions are
2570 not '==' only if one is a function-local extern function or if
2571 both are extern "C". */
2574 equal_functions (tree fn1, tree fn2)
2576 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2577 || DECL_EXTERN_C_FUNCTION_P (fn1))
2578 return decls_match (fn1, fn2);
2582 /* Print information about one overload candidate CANDIDATE. MSGSTR
2583 is the text to print before the candidate itself.
2585 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2586 to have been run through gettext by the caller. This wart makes
2587 life simpler in print_z_candidates and for the translators. */
2590 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2592 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2594 if (candidate->num_convs == 3)
2595 inform (input_location, "%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2596 candidate->convs[0]->type,
2597 candidate->convs[1]->type,
2598 candidate->convs[2]->type);
2599 else if (candidate->num_convs == 2)
2600 inform (input_location, "%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2601 candidate->convs[0]->type,
2602 candidate->convs[1]->type);
2604 inform (input_location, "%s %D(%T) <built-in>", msgstr, candidate->fn,
2605 candidate->convs[0]->type);
2607 else if (TYPE_P (candidate->fn))
2608 inform (input_location, "%s %T <conversion>", msgstr, candidate->fn);
2609 else if (candidate->viable == -1)
2610 inform (input_location, "%s %+#D <near match>", msgstr, candidate->fn);
2612 inform (input_location, "%s %+#D", msgstr, candidate->fn);
2616 print_z_candidates (struct z_candidate *candidates)
2619 struct z_candidate *cand1;
2620 struct z_candidate **cand2;
2622 /* There may be duplicates in the set of candidates. We put off
2623 checking this condition as long as possible, since we have no way
2624 to eliminate duplicates from a set of functions in less than n^2
2625 time. Now we are about to emit an error message, so it is more
2626 permissible to go slowly. */
2627 for (cand1 = candidates; cand1; cand1 = cand1->next)
2629 tree fn = cand1->fn;
2630 /* Skip builtin candidates and conversion functions. */
2631 if (TREE_CODE (fn) != FUNCTION_DECL)
2633 cand2 = &cand1->next;
2636 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2637 && equal_functions (fn, (*cand2)->fn))
2638 *cand2 = (*cand2)->next;
2640 cand2 = &(*cand2)->next;
2647 str = _("candidates are:");
2648 print_z_candidate (str, candidates);
2649 if (candidates->next)
2651 /* Indent successive candidates by the width of the translation
2652 of the above string. */
2653 size_t len = gcc_gettext_width (str) + 1;
2654 char *spaces = (char *) alloca (len);
2655 memset (spaces, ' ', len-1);
2656 spaces[len - 1] = '\0';
2658 candidates = candidates->next;
2661 print_z_candidate (spaces, candidates);
2662 candidates = candidates->next;
2668 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2669 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2670 the result of the conversion function to convert it to the final
2671 desired type. Merge the two sequences into a single sequence,
2672 and return the merged sequence. */
2675 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2679 gcc_assert (user_seq->kind == ck_user);
2681 /* Find the end of the second conversion sequence. */
2683 while ((*t)->kind != ck_identity)
2684 t = &((*t)->u.next);
2686 /* Replace the identity conversion with the user conversion
2690 /* The entire sequence is a user-conversion sequence. */
2691 std_seq->user_conv_p = true;
2696 /* Returns the best overload candidate to perform the requested
2697 conversion. This function is used for three the overloading situations
2698 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2699 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2700 per [dcl.init.ref], so we ignore temporary bindings. */
2702 static struct z_candidate *
2703 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2705 struct z_candidate *candidates, *cand;
2706 tree fromtype = TREE_TYPE (expr);
2707 tree ctors = NULL_TREE;
2708 tree conv_fns = NULL_TREE;
2709 conversion *conv = NULL;
2710 tree args = NULL_TREE;
2714 /* We represent conversion within a hierarchy using RVALUE_CONV and
2715 BASE_CONV, as specified by [over.best.ics]; these become plain
2716 constructor calls, as specified in [dcl.init]. */
2717 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
2718 || !DERIVED_FROM_P (totype, fromtype));
2720 if (MAYBE_CLASS_TYPE_P (totype))
2721 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2723 if (MAYBE_CLASS_TYPE_P (fromtype))
2725 tree to_nonref = non_reference (totype);
2726 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
2727 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
2728 && DERIVED_FROM_P (to_nonref, fromtype)))
2730 /* [class.conv.fct] A conversion function is never used to
2731 convert a (possibly cv-qualified) object to the (possibly
2732 cv-qualified) same object type (or a reference to it), to a
2733 (possibly cv-qualified) base class of that type (or a
2734 reference to it)... */
2737 conv_fns = lookup_conversions (fromtype);
2741 flags |= LOOKUP_NO_CONVERSION;
2743 /* It's OK to bind a temporary for converting constructor arguments, but
2744 not in converting the return value of a conversion operator. */
2745 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
2746 flags &= ~LOOKUP_NO_TEMP_BIND;
2752 ctors = BASELINK_FUNCTIONS (ctors);
2754 t = build_int_cst (build_pointer_type (totype), 0);
2755 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
2756 && !TYPE_HAS_LIST_CTOR (totype))
2758 args = ctor_to_list (expr);
2759 /* We still allow more conversions within an init-list. */
2760 flags = ((flags & ~LOOKUP_NO_CONVERSION)
2761 /* But not for the copy ctor. */
2762 |LOOKUP_NO_COPY_CTOR_CONVERSION
2763 |LOOKUP_NO_NARROWING);
2766 args = build_tree_list (NULL_TREE, expr);
2767 /* We should never try to call the abstract or base constructor
2769 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2770 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2771 args = tree_cons (NULL_TREE, t, args);
2773 for (; ctors; ctors = OVL_NEXT (ctors))
2775 tree ctor = OVL_CURRENT (ctors);
2776 if (DECL_NONCONVERTING_P (ctor)
2777 && !BRACE_ENCLOSED_INITIALIZER_P (expr))
2780 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2781 cand = add_template_candidate (&candidates, ctor, totype,
2782 NULL_TREE, args, NULL_TREE,
2783 TYPE_BINFO (totype),
2784 TYPE_BINFO (totype),
2788 cand = add_function_candidate (&candidates, ctor, totype,
2789 args, TYPE_BINFO (totype),
2790 TYPE_BINFO (totype),
2795 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2797 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
2798 set, then this is copy-initialization. In that case, "The
2799 result of the call is then used to direct-initialize the
2800 object that is the destination of the copy-initialization."
2803 We represent this in the conversion sequence with an
2804 rvalue conversion, which means a constructor call. */
2805 if (TREE_CODE (totype) != REFERENCE_TYPE
2806 && !(convflags & LOOKUP_NO_TEMP_BIND))
2808 = build_conv (ck_rvalue, totype, cand->second_conv);
2813 args = build_tree_list (NULL_TREE, build_this (expr));
2815 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2818 tree conversion_path = TREE_PURPOSE (conv_fns);
2820 /* If we are called to convert to a reference type, we are trying to
2821 find an lvalue binding, so don't even consider temporaries. If
2822 we don't find an lvalue binding, the caller will try again to
2823 look for a temporary binding. */
2824 if (TREE_CODE (totype) == REFERENCE_TYPE)
2825 convflags |= LOOKUP_NO_TEMP_BIND;
2827 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2829 tree fn = OVL_CURRENT (fns);
2831 /* [over.match.funcs] For conversion functions, the function
2832 is considered to be a member of the class of the implicit
2833 object argument for the purpose of defining the type of
2834 the implicit object parameter.
2836 So we pass fromtype as CTYPE to add_*_candidate. */
2838 if (TREE_CODE (fn) == TEMPLATE_DECL)
2839 cand = add_template_candidate (&candidates, fn, fromtype,
2842 TYPE_BINFO (fromtype),
2847 cand = add_function_candidate (&candidates, fn, fromtype,
2849 TYPE_BINFO (fromtype),
2856 = implicit_conversion (totype,
2857 TREE_TYPE (TREE_TYPE (cand->fn)),
2859 /*c_cast_p=*/false, convflags);
2861 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
2862 copy-initialization. In that case, "The result of the
2863 call is then used to direct-initialize the object that is
2864 the destination of the copy-initialization." [dcl.init]
2866 We represent this in the conversion sequence with an
2867 rvalue conversion, which means a constructor call. But
2868 don't add a second rvalue conversion if there's already
2869 one there. Which there really shouldn't be, but it's
2870 harmless since we'd add it here anyway. */
2871 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
2872 && !(convflags & LOOKUP_NO_TEMP_BIND))
2873 ics = build_conv (ck_rvalue, totype, ics);
2875 cand->second_conv = ics;
2879 else if (candidates->viable == 1 && ics->bad_p)
2885 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2889 cand = tourney (candidates);
2892 if (flags & LOOKUP_COMPLAIN)
2894 error ("conversion from %qT to %qT is ambiguous",
2896 print_z_candidates (candidates);
2899 cand = candidates; /* any one will do */
2900 cand->second_conv = build_ambiguous_conv (totype, expr);
2901 cand->second_conv->user_conv_p = true;
2902 if (!any_strictly_viable (candidates))
2903 cand->second_conv->bad_p = true;
2904 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2905 ambiguous conversion is no worse than another user-defined
2911 /* Build the user conversion sequence. */
2914 (DECL_CONSTRUCTOR_P (cand->fn)
2915 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2916 build_identity_conv (TREE_TYPE (expr), expr));
2919 /* Remember that this was a list-initialization. */
2920 if (flags & LOOKUP_NO_NARROWING)
2921 conv->check_narrowing = true;
2923 /* Combine it with the second conversion sequence. */
2924 cand->second_conv = merge_conversion_sequences (conv,
2927 if (cand->viable == -1)
2928 cand->second_conv->bad_p = true;
2934 build_user_type_conversion (tree totype, tree expr, int flags)
2936 struct z_candidate *cand
2937 = build_user_type_conversion_1 (totype, expr, flags);
2941 if (cand->second_conv->kind == ck_ambig)
2942 return error_mark_node;
2943 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
2944 return convert_from_reference (expr);
2949 /* Do any initial processing on the arguments to a function call. */
2952 resolve_args (tree args)
2955 for (t = args; t; t = TREE_CHAIN (t))
2957 tree arg = TREE_VALUE (t);
2959 if (error_operand_p (arg))
2960 return error_mark_node;
2961 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2963 error ("invalid use of void expression");
2964 return error_mark_node;
2966 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
2967 return error_mark_node;
2972 /* Perform overload resolution on FN, which is called with the ARGS.
2974 Return the candidate function selected by overload resolution, or
2975 NULL if the event that overload resolution failed. In the case
2976 that overload resolution fails, *CANDIDATES will be the set of
2977 candidates considered, and ANY_VIABLE_P will be set to true or
2978 false to indicate whether or not any of the candidates were
2981 The ARGS should already have gone through RESOLVE_ARGS before this
2982 function is called. */
2984 static struct z_candidate *
2985 perform_overload_resolution (tree fn,
2987 struct z_candidate **candidates,
2990 struct z_candidate *cand;
2991 tree explicit_targs = NULL_TREE;
2992 int template_only = 0;
2995 *any_viable_p = true;
2997 /* Check FN and ARGS. */
2998 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2999 || TREE_CODE (fn) == TEMPLATE_DECL
3000 || TREE_CODE (fn) == OVERLOAD
3001 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3002 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
3004 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3006 explicit_targs = TREE_OPERAND (fn, 1);
3007 fn = TREE_OPERAND (fn, 0);
3011 /* Add the various candidate functions. */
3012 add_candidates (fn, args, explicit_targs, template_only,
3013 /*conversion_path=*/NULL_TREE,
3014 /*access_path=*/NULL_TREE,
3018 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3022 cand = tourney (*candidates);
3026 /* Return an expression for a call to FN (a namespace-scope function,
3027 or a static member function) with the ARGS. */
3030 build_new_function_call (tree fn, tree args, bool koenig_p,
3031 tsubst_flags_t complain)
3033 struct z_candidate *candidates, *cand;
3038 args = resolve_args (args);
3039 if (args == error_mark_node)
3040 return error_mark_node;
3042 /* If this function was found without using argument dependent
3043 lookup, then we want to ignore any undeclared friend
3049 fn = remove_hidden_names (fn);
3052 if (complain & tf_error)
3053 error ("no matching function for call to %<%D(%A)%>",
3054 DECL_NAME (OVL_CURRENT (orig_fn)), args);
3055 return error_mark_node;
3059 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3060 p = conversion_obstack_alloc (0);
3062 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
3066 if (complain & tf_error)
3068 if (!any_viable_p && candidates && ! candidates->next)
3069 return cp_build_function_call (candidates->fn, args, complain);
3070 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3071 fn = TREE_OPERAND (fn, 0);
3073 error ("no matching function for call to %<%D(%A)%>",
3074 DECL_NAME (OVL_CURRENT (fn)), args);
3076 error ("call of overloaded %<%D(%A)%> is ambiguous",
3077 DECL_NAME (OVL_CURRENT (fn)), args);
3079 print_z_candidates (candidates);
3081 result = error_mark_node;
3084 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3086 /* Free all the conversions we allocated. */
3087 obstack_free (&conversion_obstack, p);
3092 /* Build a call to a global operator new. FNNAME is the name of the
3093 operator (either "operator new" or "operator new[]") and ARGS are
3094 the arguments provided. *SIZE points to the total number of bytes
3095 required by the allocation, and is updated if that is changed here.
3096 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
3097 function determines that no cookie should be used, after all,
3098 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
3099 set, upon return, to the allocation function called. */
3102 build_operator_new_call (tree fnname, tree args,
3103 tree *size, tree *cookie_size,
3107 struct z_candidate *candidates;
3108 struct z_candidate *cand;
3113 args = tree_cons (NULL_TREE, *size, args);
3114 args = resolve_args (args);
3115 if (args == error_mark_node)
3122 If this lookup fails to find the name, or if the allocated type
3123 is not a class type, the allocation function's name is looked
3124 up in the global scope.
3126 we disregard block-scope declarations of "operator new". */
3127 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
3129 /* Figure out what function is being called. */
3130 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
3132 /* If no suitable function could be found, issue an error message
3137 error ("no matching function for call to %<%D(%A)%>",
3138 DECL_NAME (OVL_CURRENT (fns)), args);
3140 error ("call of overloaded %<%D(%A)%> is ambiguous",
3141 DECL_NAME (OVL_CURRENT (fns)), args);
3143 print_z_candidates (candidates);
3144 return error_mark_node;
3147 /* If a cookie is required, add some extra space. Whether
3148 or not a cookie is required cannot be determined until
3149 after we know which function was called. */
3152 bool use_cookie = true;
3153 if (!abi_version_at_least (2))
3155 tree placement = TREE_CHAIN (args);
3156 /* In G++ 3.2, the check was implemented incorrectly; it
3157 looked at the placement expression, rather than the
3158 type of the function. */
3159 if (placement && !TREE_CHAIN (placement)
3160 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
3168 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3169 /* Skip the size_t parameter. */
3170 arg_types = TREE_CHAIN (arg_types);
3171 /* Check the remaining parameters (if any). */
3173 && TREE_CHAIN (arg_types) == void_list_node
3174 && same_type_p (TREE_VALUE (arg_types),
3178 /* If we need a cookie, adjust the number of bytes allocated. */
3181 /* Update the total size. */
3182 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3183 /* Update the argument list to reflect the adjusted size. */
3184 TREE_VALUE (args) = *size;
3187 *cookie_size = NULL_TREE;
3190 /* Tell our caller which function we decided to call. */
3194 /* Build the CALL_EXPR. */
3195 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3199 build_object_call (tree obj, tree args, tsubst_flags_t complain)
3201 struct z_candidate *candidates = 0, *cand;
3202 tree fns, convs, mem_args = NULL_TREE;
3203 tree type = TREE_TYPE (obj);
3205 tree result = NULL_TREE;
3208 if (TYPE_PTRMEMFUNC_P (type))
3210 if (complain & tf_error)
3211 /* It's no good looking for an overloaded operator() on a
3212 pointer-to-member-function. */
3213 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3214 return error_mark_node;
3217 if (TYPE_BINFO (type))
3219 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3220 if (fns == error_mark_node)
3221 return error_mark_node;
3226 args = resolve_args (args);
3228 if (args == error_mark_node)
3229 return error_mark_node;
3231 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3232 p = conversion_obstack_alloc (0);
3236 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
3237 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
3239 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3241 tree fn = OVL_CURRENT (fns);
3242 if (TREE_CODE (fn) == TEMPLATE_DECL)
3243 add_template_candidate (&candidates, fn, base, NULL_TREE,
3244 mem_args, NULL_TREE,
3247 LOOKUP_NORMAL, DEDUCE_CALL);
3249 add_function_candidate
3250 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3251 TYPE_BINFO (type), LOOKUP_NORMAL);
3255 convs = lookup_conversions (type);
3257 for (; convs; convs = TREE_CHAIN (convs))
3259 tree fns = TREE_VALUE (convs);
3260 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3262 if ((TREE_CODE (totype) == POINTER_TYPE
3263 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3264 || (TREE_CODE (totype) == REFERENCE_TYPE
3265 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3266 || (TREE_CODE (totype) == REFERENCE_TYPE
3267 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3268 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3269 for (; fns; fns = OVL_NEXT (fns))
3271 tree fn = OVL_CURRENT (fns);
3272 if (TREE_CODE (fn) == TEMPLATE_DECL)
3273 add_template_conv_candidate
3274 (&candidates, fn, obj, args, totype,
3275 /*access_path=*/NULL_TREE,
3276 /*conversion_path=*/NULL_TREE);
3278 add_conv_candidate (&candidates, fn, obj, args,
3279 /*conversion_path=*/NULL_TREE,
3280 /*access_path=*/NULL_TREE);
3284 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3287 if (complain & tf_error)
3289 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3290 print_z_candidates (candidates);
3292 result = error_mark_node;
3296 cand = tourney (candidates);
3299 if (complain & tf_error)
3301 error ("call of %<(%T) (%A)%> is ambiguous",
3302 TREE_TYPE (obj), args);
3303 print_z_candidates (candidates);
3305 result = error_mark_node;
3307 /* Since cand->fn will be a type, not a function, for a conversion
3308 function, we must be careful not to unconditionally look at
3310 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3311 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3312 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3315 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
3317 obj = convert_from_reference (obj);
3318 result = cp_build_function_call (obj, args, complain);
3322 /* Free all the conversions we allocated. */
3323 obstack_free (&conversion_obstack, p);
3329 op_error (enum tree_code code, enum tree_code code2,
3330 tree arg1, tree arg2, tree arg3, const char *problem)
3334 if (code == MODIFY_EXPR)
3335 opname = assignment_operator_name_info[code2].name;
3337 opname = operator_name_info[code].name;
3342 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3343 problem, arg1, arg2, arg3);
3346 case POSTINCREMENT_EXPR:
3347 case POSTDECREMENT_EXPR:
3348 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3352 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3357 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3362 error ("%s for %<operator%s%> in %<%E %s %E%>",
3363 problem, opname, arg1, opname, arg2);
3365 error ("%s for %<operator%s%> in %<%s%E%>",
3366 problem, opname, opname, arg1);
3371 /* Return the implicit conversion sequence that could be used to
3372 convert E1 to E2 in [expr.cond]. */
3375 conditional_conversion (tree e1, tree e2)
3377 tree t1 = non_reference (TREE_TYPE (e1));
3378 tree t2 = non_reference (TREE_TYPE (e2));
3384 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3385 implicitly converted (clause _conv_) to the type "reference to
3386 T2", subject to the constraint that in the conversion the
3387 reference must bind directly (_dcl.init.ref_) to E1. */
3388 if (real_lvalue_p (e2))
3390 conv = implicit_conversion (build_reference_type (t2),
3394 LOOKUP_NO_TEMP_BIND);
3401 If E1 and E2 have class type, and the underlying class types are
3402 the same or one is a base class of the other: E1 can be converted
3403 to match E2 if the class of T2 is the same type as, or a base
3404 class of, the class of T1, and the cv-qualification of T2 is the
3405 same cv-qualification as, or a greater cv-qualification than, the
3406 cv-qualification of T1. If the conversion is applied, E1 is
3407 changed to an rvalue of type T2 that still refers to the original
3408 source class object (or the appropriate subobject thereof). */
3409 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3410 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3412 if (good_base && at_least_as_qualified_p (t2, t1))
3414 conv = build_identity_conv (t1, e1);
3415 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3416 TYPE_MAIN_VARIANT (t2)))
3417 conv = build_conv (ck_base, t2, conv);
3419 conv = build_conv (ck_rvalue, t2, conv);
3428 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3429 converted to the type that expression E2 would have if E2 were
3430 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3431 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3435 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3436 arguments to the conditional expression. */
3439 build_conditional_expr (tree arg1, tree arg2, tree arg3,
3440 tsubst_flags_t complain)
3444 tree result = NULL_TREE;
3445 tree result_type = NULL_TREE;
3446 bool lvalue_p = true;
3447 struct z_candidate *candidates = 0;
3448 struct z_candidate *cand;
3451 /* As a G++ extension, the second argument to the conditional can be
3452 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3453 c'.) If the second operand is omitted, make sure it is
3454 calculated only once. */
3457 if (complain & tf_error)
3458 pedwarn (input_location, OPT_pedantic,
3459 "ISO C++ forbids omitting the middle term of a ?: expression");
3461 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3462 if (real_lvalue_p (arg1))
3463 arg2 = arg1 = stabilize_reference (arg1);
3465 arg2 = arg1 = save_expr (arg1);
3470 The first expression is implicitly converted to bool (clause
3472 arg1 = perform_implicit_conversion (boolean_type_node, arg1, complain);
3474 /* If something has already gone wrong, just pass that fact up the
3476 if (error_operand_p (arg1)
3477 || error_operand_p (arg2)
3478 || error_operand_p (arg3))
3479 return error_mark_node;
3483 If either the second or the third operand has type (possibly
3484 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3485 array-to-pointer (_conv.array_), and function-to-pointer
3486 (_conv.func_) standard conversions are performed on the second
3487 and third operands. */
3488 arg2_type = unlowered_expr_type (arg2);
3489 arg3_type = unlowered_expr_type (arg3);
3490 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3492 /* Do the conversions. We don't these for `void' type arguments
3493 since it can't have any effect and since decay_conversion
3494 does not handle that case gracefully. */
3495 if (!VOID_TYPE_P (arg2_type))
3496 arg2 = decay_conversion (arg2);
3497 if (!VOID_TYPE_P (arg3_type))
3498 arg3 = decay_conversion (arg3);
3499 arg2_type = TREE_TYPE (arg2);
3500 arg3_type = TREE_TYPE (arg3);
3504 One of the following shall hold:
3506 --The second or the third operand (but not both) is a
3507 throw-expression (_except.throw_); the result is of the
3508 type of the other and is an rvalue.
3510 --Both the second and the third operands have type void; the
3511 result is of type void and is an rvalue.
3513 We must avoid calling force_rvalue for expressions of type
3514 "void" because it will complain that their value is being
3516 if (TREE_CODE (arg2) == THROW_EXPR
3517 && TREE_CODE (arg3) != THROW_EXPR)
3519 if (!VOID_TYPE_P (arg3_type))
3520 arg3 = force_rvalue (arg3);
3521 arg3_type = TREE_TYPE (arg3);
3522 result_type = arg3_type;
3524 else if (TREE_CODE (arg2) != THROW_EXPR
3525 && TREE_CODE (arg3) == THROW_EXPR)
3527 if (!VOID_TYPE_P (arg2_type))
3528 arg2 = force_rvalue (arg2);
3529 arg2_type = TREE_TYPE (arg2);
3530 result_type = arg2_type;
3532 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3533 result_type = void_type_node;
3536 if (complain & tf_error)
3538 if (VOID_TYPE_P (arg2_type))
3539 error ("second operand to the conditional operator "
3540 "is of type %<void%>, "
3541 "but the third operand is neither a throw-expression "
3542 "nor of type %<void%>");
3544 error ("third operand to the conditional operator "
3545 "is of type %<void%>, "
3546 "but the second operand is neither a throw-expression "
3547 "nor of type %<void%>");
3549 return error_mark_node;
3553 goto valid_operands;
3557 Otherwise, if the second and third operand have different types,
3558 and either has (possibly cv-qualified) class type, an attempt is
3559 made to convert each of those operands to the type of the other. */
3560 else if (!same_type_p (arg2_type, arg3_type)
3561 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3566 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3567 p = conversion_obstack_alloc (0);
3569 conv2 = conditional_conversion (arg2, arg3);
3570 conv3 = conditional_conversion (arg3, arg2);
3574 If both can be converted, or one can be converted but the
3575 conversion is ambiguous, the program is ill-formed. If
3576 neither can be converted, the operands are left unchanged and
3577 further checking is performed as described below. If exactly
3578 one conversion is possible, that conversion is applied to the
3579 chosen operand and the converted operand is used in place of
3580 the original operand for the remainder of this section. */
3581 if ((conv2 && !conv2->bad_p
3582 && conv3 && !conv3->bad_p)
3583 || (conv2 && conv2->kind == ck_ambig)
3584 || (conv3 && conv3->kind == ck_ambig))
3586 error ("operands to ?: have different types %qT and %qT",
3587 arg2_type, arg3_type);
3588 result = error_mark_node;
3590 else if (conv2 && (!conv2->bad_p || !conv3))
3592 arg2 = convert_like (conv2, arg2, complain);
3593 arg2 = convert_from_reference (arg2);
3594 arg2_type = TREE_TYPE (arg2);
3595 /* Even if CONV2 is a valid conversion, the result of the
3596 conversion may be invalid. For example, if ARG3 has type
3597 "volatile X", and X does not have a copy constructor
3598 accepting a "volatile X&", then even if ARG2 can be
3599 converted to X, the conversion will fail. */
3600 if (error_operand_p (arg2))
3601 result = error_mark_node;
3603 else if (conv3 && (!conv3->bad_p || !conv2))
3605 arg3 = convert_like (conv3, arg3, complain);
3606 arg3 = convert_from_reference (arg3);
3607 arg3_type = TREE_TYPE (arg3);
3608 if (error_operand_p (arg3))
3609 result = error_mark_node;
3612 /* Free all the conversions we allocated. */
3613 obstack_free (&conversion_obstack, p);
3618 /* If, after the conversion, both operands have class type,
3619 treat the cv-qualification of both operands as if it were the
3620 union of the cv-qualification of the operands.
3622 The standard is not clear about what to do in this
3623 circumstance. For example, if the first operand has type
3624 "const X" and the second operand has a user-defined
3625 conversion to "volatile X", what is the type of the second
3626 operand after this step? Making it be "const X" (matching
3627 the first operand) seems wrong, as that discards the
3628 qualification without actually performing a copy. Leaving it
3629 as "volatile X" seems wrong as that will result in the
3630 conditional expression failing altogether, even though,
3631 according to this step, the one operand could be converted to
3632 the type of the other. */
3633 if ((conv2 || conv3)
3634 && CLASS_TYPE_P (arg2_type)
3635 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3636 arg2_type = arg3_type =
3637 cp_build_qualified_type (arg2_type,
3638 TYPE_QUALS (arg2_type)
3639 | TYPE_QUALS (arg3_type));
3644 If the second and third operands are lvalues and have the same
3645 type, the result is of that type and is an lvalue. */
3646 if (real_lvalue_p (arg2)
3647 && real_lvalue_p (arg3)
3648 && same_type_p (arg2_type, arg3_type))
3650 result_type = arg2_type;
3651 goto valid_operands;
3656 Otherwise, the result is an rvalue. If the second and third
3657 operand do not have the same type, and either has (possibly
3658 cv-qualified) class type, overload resolution is used to
3659 determine the conversions (if any) to be applied to the operands
3660 (_over.match.oper_, _over.built_). */
3662 if (!same_type_p (arg2_type, arg3_type)
3663 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3669 /* Rearrange the arguments so that add_builtin_candidate only has
3670 to know about two args. In build_builtin_candidates, the
3671 arguments are unscrambled. */
3675 add_builtin_candidates (&candidates,
3678 ansi_opname (COND_EXPR),
3684 If the overload resolution fails, the program is
3686 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3689 if (complain & tf_error)
3691 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3692 print_z_candidates (candidates);
3694 return error_mark_node;
3696 cand = tourney (candidates);
3699 if (complain & tf_error)
3701 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3702 print_z_candidates (candidates);
3704 return error_mark_node;
3709 Otherwise, the conversions thus determined are applied, and
3710 the converted operands are used in place of the original
3711 operands for the remainder of this section. */
3712 conv = cand->convs[0];
3713 arg1 = convert_like (conv, arg1, complain);
3714 conv = cand->convs[1];
3715 arg2 = convert_like (conv, arg2, complain);
3716 conv = cand->convs[2];
3717 arg3 = convert_like (conv, arg3, complain);
3722 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3723 and function-to-pointer (_conv.func_) standard conversions are
3724 performed on the second and third operands.
3726 We need to force the lvalue-to-rvalue conversion here for class types,
3727 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3728 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3731 arg2 = force_rvalue (arg2);
3732 if (!CLASS_TYPE_P (arg2_type))
3733 arg2_type = TREE_TYPE (arg2);
3735 arg3 = force_rvalue (arg3);
3736 if (!CLASS_TYPE_P (arg2_type))
3737 arg3_type = TREE_TYPE (arg3);
3739 if (arg2 == error_mark_node || arg3 == error_mark_node)
3740 return error_mark_node;
3744 After those conversions, one of the following shall hold:
3746 --The second and third operands have the same type; the result is of
3748 if (same_type_p (arg2_type, arg3_type))
3749 result_type = arg2_type;
3752 --The second and third operands have arithmetic or enumeration
3753 type; the usual arithmetic conversions are performed to bring
3754 them to a common type, and the result is of that type. */
3755 else if ((ARITHMETIC_TYPE_P (arg2_type)
3756 || UNSCOPED_ENUM_P (arg2_type))
3757 && (ARITHMETIC_TYPE_P (arg3_type)
3758 || UNSCOPED_ENUM_P (arg3_type)))
3760 /* In this case, there is always a common type. */
3761 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3764 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3765 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3767 if (complain & tf_warning)
3769 "enumeral mismatch in conditional expression: %qT vs %qT",
3770 arg2_type, arg3_type);
3772 else if (extra_warnings
3773 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3774 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3775 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3776 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3778 if (complain & tf_warning)
3780 "enumeral and non-enumeral type in conditional expression");
3783 arg2 = perform_implicit_conversion (result_type, arg2, complain);
3784 arg3 = perform_implicit_conversion (result_type, arg3, complain);
3788 --The second and third operands have pointer type, or one has
3789 pointer type and the other is a null pointer constant; pointer
3790 conversions (_conv.ptr_) and qualification conversions
3791 (_conv.qual_) are performed to bring them to their composite
3792 pointer type (_expr.rel_). The result is of the composite
3795 --The second and third operands have pointer to member type, or
3796 one has pointer to member type and the other is a null pointer
3797 constant; pointer to member conversions (_conv.mem_) and
3798 qualification conversions (_conv.qual_) are performed to bring
3799 them to a common type, whose cv-qualification shall match the
3800 cv-qualification of either the second or the third operand.
3801 The result is of the common type. */
3802 else if ((null_ptr_cst_p (arg2)
3803 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3804 || (null_ptr_cst_p (arg3)
3805 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3806 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3807 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3808 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3810 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3811 arg3, "conditional expression",
3813 if (result_type == error_mark_node)
3814 return error_mark_node;
3815 arg2 = perform_implicit_conversion (result_type, arg2, complain);
3816 arg3 = perform_implicit_conversion (result_type, arg3, complain);
3821 if (complain & tf_error)
3822 error ("operands to ?: have different types %qT and %qT",
3823 arg2_type, arg3_type);
3824 return error_mark_node;
3828 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3830 /* We can't use result_type below, as fold might have returned a
3835 /* Expand both sides into the same slot, hopefully the target of
3836 the ?: expression. We used to check for TARGET_EXPRs here,
3837 but now we sometimes wrap them in NOP_EXPRs so the test would
3839 if (CLASS_TYPE_P (TREE_TYPE (result)))
3840 result = get_target_expr (result);
3841 /* If this expression is an rvalue, but might be mistaken for an
3842 lvalue, we must add a NON_LVALUE_EXPR. */
3843 result = rvalue (result);
3849 /* OPERAND is an operand to an expression. Perform necessary steps
3850 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3854 prep_operand (tree operand)
3858 if (CLASS_TYPE_P (TREE_TYPE (operand))
3859 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3860 /* Make sure the template type is instantiated now. */
3861 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3867 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3868 OVERLOAD) to the CANDIDATES, returning an updated list of
3869 CANDIDATES. The ARGS are the arguments provided to the call,
3870 without any implicit object parameter. The EXPLICIT_TARGS are
3871 explicit template arguments provided. TEMPLATE_ONLY is true if
3872 only template functions should be considered. CONVERSION_PATH,
3873 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3876 add_candidates (tree fns, tree args,
3877 tree explicit_targs, bool template_only,
3878 tree conversion_path, tree access_path,
3880 struct z_candidate **candidates)
3883 tree non_static_args;
3885 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3886 /* Delay creating the implicit this parameter until it is needed. */
3887 non_static_args = NULL_TREE;
3894 fn = OVL_CURRENT (fns);
3895 /* Figure out which set of arguments to use. */
3896 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3898 /* If this function is a non-static member, prepend the implicit
3899 object parameter. */
3900 if (!non_static_args)
3901 non_static_args = tree_cons (NULL_TREE,
3902 build_this (TREE_VALUE (args)),
3904 fn_args = non_static_args;
3907 /* Otherwise, just use the list of arguments provided. */
3910 if (TREE_CODE (fn) == TEMPLATE_DECL)
3911 add_template_candidate (candidates,
3921 else if (!template_only)
3922 add_function_candidate (candidates,
3929 fns = OVL_NEXT (fns);
3934 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3935 bool *overloaded_p, tsubst_flags_t complain)
3937 struct z_candidate *candidates = 0, *cand;
3938 tree arglist, fnname;
3940 tree result = NULL_TREE;
3941 bool result_valid_p = false;
3942 enum tree_code code2 = NOP_EXPR;
3947 bool expl_eq_arg1 = false;
3949 if (error_operand_p (arg1)
3950 || error_operand_p (arg2)
3951 || error_operand_p (arg3))
3952 return error_mark_node;
3954 if (code == MODIFY_EXPR)
3956 code2 = TREE_CODE (arg3);
3958 fnname = ansi_assopname (code2);
3961 fnname = ansi_opname (code);
3963 arg1 = prep_operand (arg1);
3969 case VEC_DELETE_EXPR:
3971 /* Use build_op_new_call and build_op_delete_call instead. */
3975 return build_object_call (arg1, arg2, complain);
3977 case TRUTH_ORIF_EXPR:
3978 case TRUTH_ANDIF_EXPR:
3979 case TRUTH_AND_EXPR:
3981 if (COMPARISON_CLASS_P (arg1))
3982 expl_eq_arg1 = true;
3987 arg2 = prep_operand (arg2);
3988 arg3 = prep_operand (arg3);
3990 if (code == COND_EXPR)
3992 if (arg2 == NULL_TREE
3993 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3994 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3995 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3996 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3999 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
4000 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4003 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4004 arg2 = integer_zero_node;
4006 arglist = NULL_TREE;
4008 arglist = tree_cons (NULL_TREE, arg3, arglist);
4010 arglist = tree_cons (NULL_TREE, arg2, arglist);
4011 arglist = tree_cons (NULL_TREE, arg1, arglist);
4013 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4014 p = conversion_obstack_alloc (0);
4016 /* Add namespace-scope operators to the list of functions to
4018 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4019 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
4020 flags, &candidates);
4021 /* Add class-member operators to the candidate set. */
4022 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4026 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4027 if (fns == error_mark_node)
4029 result = error_mark_node;
4030 goto user_defined_result_ready;
4033 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
4035 BASELINK_BINFO (fns),
4036 TYPE_BINFO (TREE_TYPE (arg1)),
4037 flags, &candidates);
4040 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
4041 to know about two args; a builtin candidate will always have a first
4042 parameter of type bool. We'll handle that in
4043 build_builtin_candidate. */
4044 if (code == COND_EXPR)
4054 args[2] = NULL_TREE;
4057 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4063 /* For these, the built-in candidates set is empty
4064 [over.match.oper]/3. We don't want non-strict matches
4065 because exact matches are always possible with built-in
4066 operators. The built-in candidate set for COMPONENT_REF
4067 would be empty too, but since there are no such built-in
4068 operators, we accept non-strict matches for them. */
4073 strict_p = pedantic;
4077 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4082 case POSTINCREMENT_EXPR:
4083 case POSTDECREMENT_EXPR:
4084 /* Don't try anything fancy if we're not allowed to produce
4086 if (!(complain & tf_error))
4087 return error_mark_node;
4089 /* Look for an `operator++ (int)'. If they didn't have
4090 one, then we fall back to the old way of doing things. */
4091 if (flags & LOOKUP_COMPLAIN)
4092 permerror (input_location, "no %<%D(int)%> declared for postfix %qs, "
4093 "trying prefix operator instead",
4095 operator_name_info[code].name);
4096 if (code == POSTINCREMENT_EXPR)
4097 code = PREINCREMENT_EXPR;
4099 code = PREDECREMENT_EXPR;
4100 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
4101 overloaded_p, complain);
4104 /* The caller will deal with these. */
4109 result_valid_p = true;
4113 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4115 /* If one of the arguments of the operator represents
4116 an invalid use of member function pointer, try to report
4117 a meaningful error ... */
4118 if (invalid_nonstatic_memfn_p (arg1, tf_error)
4119 || invalid_nonstatic_memfn_p (arg2, tf_error)
4120 || invalid_nonstatic_memfn_p (arg3, tf_error))
4121 /* We displayed the error message. */;
4124 /* ... Otherwise, report the more generic
4125 "no matching operator found" error */
4126 op_error (code, code2, arg1, arg2, arg3, "no match");
4127 print_z_candidates (candidates);
4130 result = error_mark_node;
4136 cand = tourney (candidates);
4139 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4141 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
4142 print_z_candidates (candidates);
4144 result = error_mark_node;
4146 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4149 *overloaded_p = true;
4151 if (resolve_args (arglist) == error_mark_node)
4152 result = error_mark_node;
4154 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4158 /* Give any warnings we noticed during overload resolution. */
4159 if (cand->warnings && (complain & tf_warning))
4161 struct candidate_warning *w;
4162 for (w = cand->warnings; w; w = w->next)
4163 joust (cand, w->loser, 1);
4166 /* Check for comparison of different enum types. */
4175 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
4176 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
4177 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
4178 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
4179 && (complain & tf_warning))
4181 warning (OPT_Wenum_compare,
4182 "comparison between %q#T and %q#T",
4183 TREE_TYPE (arg1), TREE_TYPE (arg2));
4190 /* We need to strip any leading REF_BIND so that bitfields
4191 don't cause errors. This should not remove any important
4192 conversions, because builtins don't apply to class
4193 objects directly. */
4194 conv = cand->convs[0];
4195 if (conv->kind == ck_ref_bind)
4196 conv = conv->u.next;
4197 arg1 = convert_like (conv, arg1, complain);
4200 conv = cand->convs[1];
4201 if (conv->kind == ck_ref_bind)
4202 conv = conv->u.next;
4203 arg2 = convert_like (conv, arg2, complain);
4207 conv = cand->convs[2];
4208 if (conv->kind == ck_ref_bind)
4209 conv = conv->u.next;
4210 arg3 = convert_like (conv, arg3, complain);
4215 if (complain & tf_warning)
4216 warn_logical_operator (code, arg1, arg2);
4217 expl_eq_arg1 = true;
4222 user_defined_result_ready:
4224 /* Free all the conversions we allocated. */
4225 obstack_free (&conversion_obstack, p);
4227 if (result || result_valid_p)
4234 return cp_build_modify_expr (arg1, code2, arg2, complain);
4237 return cp_build_indirect_ref (arg1, "unary *", complain);
4239 case TRUTH_ANDIF_EXPR:
4240 case TRUTH_ORIF_EXPR:
4241 case TRUTH_AND_EXPR:
4244 warn_logical_operator (code, arg1, arg2);
4248 case TRUNC_DIV_EXPR:
4259 case TRUNC_MOD_EXPR:
4263 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
4265 case UNARY_PLUS_EXPR:
4268 case TRUTH_NOT_EXPR:
4269 case PREINCREMENT_EXPR:
4270 case POSTINCREMENT_EXPR:
4271 case PREDECREMENT_EXPR:
4272 case POSTDECREMENT_EXPR:
4275 return cp_build_unary_op (code, arg1, candidates != 0, complain);
4278 return build_array_ref (arg1, arg2, input_location);
4281 return build_conditional_expr (arg1, arg2, arg3, complain);
4284 return build_m_component_ref (cp_build_indirect_ref (arg1, NULL,
4288 /* The caller will deal with these. */
4300 /* Build a call to operator delete. This has to be handled very specially,
4301 because the restrictions on what signatures match are different from all
4302 other call instances. For a normal delete, only a delete taking (void *)
4303 or (void *, size_t) is accepted. For a placement delete, only an exact
4304 match with the placement new is accepted.
4306 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4307 ADDR is the pointer to be deleted.
4308 SIZE is the size of the memory block to be deleted.
4309 GLOBAL_P is true if the delete-expression should not consider
4310 class-specific delete operators.
4311 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4313 If this call to "operator delete" is being generated as part to
4314 deallocate memory allocated via a new-expression (as per [expr.new]
4315 which requires that if the initialization throws an exception then
4316 we call a deallocation function), then ALLOC_FN is the allocation
4320 build_op_delete_call (enum tree_code code, tree addr, tree size,
4321 bool global_p, tree placement,
4324 tree fn = NULL_TREE;
4325 tree fns, fnname, argtypes, type;
4328 if (addr == error_mark_node)
4329 return error_mark_node;
4331 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4333 fnname = ansi_opname (code);
4335 if (CLASS_TYPE_P (type)
4336 && COMPLETE_TYPE_P (complete_type (type))
4340 If the result of the lookup is ambiguous or inaccessible, or if
4341 the lookup selects a placement deallocation function, the
4342 program is ill-formed.
4344 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4346 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4347 if (fns == error_mark_node)
4348 return error_mark_node;
4353 if (fns == NULL_TREE)
4354 fns = lookup_name_nonclass (fnname);
4356 /* Strip const and volatile from addr. */
4357 addr = cp_convert (ptr_type_node, addr);
4361 /* Get the parameter types for the allocation function that is
4363 gcc_assert (alloc_fn != NULL_TREE);
4364 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4368 /* First try it without the size argument. */
4369 argtypes = void_list_node;
4372 /* We make two tries at finding a matching `operator delete'. On
4373 the first pass, we look for a one-operator (or placement)
4374 operator delete. If we're not doing placement delete, then on
4375 the second pass we look for a two-argument delete. */
4376 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4378 /* Go through the `operator delete' functions looking for one
4379 with a matching type. */
4380 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4386 /* The first argument must be "void *". */
4387 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4388 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4391 /* On the first pass, check the rest of the arguments. */
4397 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4405 /* On the second pass, look for a function with exactly two
4406 arguments: "void *" and "size_t". */
4408 /* For "operator delete(void *, ...)" there will be
4409 no second argument, but we will not get an exact
4412 && same_type_p (TREE_VALUE (t), size_type_node)
4413 && TREE_CHAIN (t) == void_list_node)
4417 /* If we found a match, we're done. */
4422 /* If we have a matching function, call it. */
4425 /* Make sure we have the actual function, and not an
4427 fn = OVL_CURRENT (fn);
4429 /* If the FN is a member function, make sure that it is
4431 if (DECL_CLASS_SCOPE_P (fn))
4432 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4436 /* The placement args might not be suitable for overload
4437 resolution at this point, so build the call directly. */
4438 int nargs = call_expr_nargs (placement);
4439 tree *argarray = (tree *) alloca (nargs * sizeof (tree));
4442 for (i = 1; i < nargs; i++)
4443 argarray[i] = CALL_EXPR_ARG (placement, i);
4445 return build_cxx_call (fn, nargs, argarray);
4451 args = tree_cons (NULL_TREE, addr, NULL_TREE);
4453 args = tree_cons (NULL_TREE, addr,
4454 build_tree_list (NULL_TREE, size));
4455 return cp_build_function_call (fn, args, tf_warning_or_error);
4461 If no unambiguous matching deallocation function can be found,
4462 propagating the exception does not cause the object's memory to
4467 warning (0, "no corresponding deallocation function for %qD",
4472 error ("no suitable %<operator %s%> for %qT",
4473 operator_name_info[(int)code].name, type);
4474 return error_mark_node;
4477 /* If the current scope isn't allowed to access DECL along
4478 BASETYPE_PATH, give an error. The most derived class in
4479 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4480 the declaration to use in the error diagnostic. */
4483 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4485 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4487 if (!accessible_p (basetype_path, decl, true))
4489 if (TREE_PRIVATE (decl))
4490 error ("%q+#D is private", diag_decl);
4491 else if (TREE_PROTECTED (decl))
4492 error ("%q+#D is protected", diag_decl);
4494 error ("%q+#D is inaccessible", diag_decl);
4495 error ("within this context");
4502 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4503 bitwise or of LOOKUP_* values. If any errors are warnings are
4504 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4505 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4509 build_temp (tree expr, tree type, int flags,
4510 diagnostic_t *diagnostic_kind)
4514 savew = warningcount, savee = errorcount;
4515 expr = build_special_member_call (NULL_TREE,
4516 complete_ctor_identifier,
4517 build_tree_list (NULL_TREE, expr),
4518 type, flags, tf_warning_or_error);
4519 if (warningcount > savew)
4520 *diagnostic_kind = DK_WARNING;
4521 else if (errorcount > savee)
4522 *diagnostic_kind = DK_ERROR;
4524 *diagnostic_kind = 0;
4528 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4529 EXPR is implicitly converted to type TOTYPE.
4530 FN and ARGNUM are used for diagnostics. */
4533 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
4535 tree t = non_reference (totype);
4537 /* Issue warnings about peculiar, but valid, uses of NULL. */
4538 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
4541 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4544 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4547 /* Issue warnings if "false" is converted to a NULL pointer */
4548 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
4549 warning (OPT_Wconversion,
4550 "converting %<false%> to pointer type for argument %P of %qD",
4554 /* Perform the conversions in CONVS on the expression EXPR. FN and
4555 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4556 indicates the `this' argument of a method. INNER is nonzero when
4557 being called to continue a conversion chain. It is negative when a
4558 reference binding will be applied, positive otherwise. If
4559 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4560 conversions will be emitted if appropriate. If C_CAST_P is true,
4561 this conversion is coming from a C-style cast; in that case,
4562 conversions to inaccessible bases are permitted. */
4565 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4566 int inner, bool issue_conversion_warnings,
4567 bool c_cast_p, tsubst_flags_t complain)
4569 tree totype = convs->type;
4570 diagnostic_t diag_kind;
4574 && convs->kind != ck_user
4575 && convs->kind != ck_list
4576 && convs->kind != ck_ambig
4577 && convs->kind != ck_ref_bind
4578 && convs->kind != ck_rvalue
4579 && convs->kind != ck_base)
4581 conversion *t = convs;
4583 /* Give a helpful error if this is bad because of excess braces. */
4584 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
4585 && SCALAR_TYPE_P (totype)
4586 && CONSTRUCTOR_NELTS (expr) > 0
4587 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
4588 permerror (input_location, "too many braces around initializer for %qT", totype);
4590 for (; t; t = convs->u.next)
4592 if (t->kind == ck_user || !t->bad_p)
4594 expr = convert_like_real (t, expr, fn, argnum, 1,
4595 /*issue_conversion_warnings=*/false,
4600 else if (t->kind == ck_ambig)
4601 return convert_like_real (t, expr, fn, argnum, 1,
4602 /*issue_conversion_warnings=*/false,
4605 else if (t->kind == ck_identity)
4608 if (complain & tf_error)
4610 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4612 permerror (input_location, " initializing argument %P of %qD", argnum, fn);
4615 return error_mark_node;
4617 return cp_convert (totype, expr);
4620 if (issue_conversion_warnings && (complain & tf_warning))
4621 conversion_null_warnings (totype, expr, fn, argnum);
4623 switch (convs->kind)
4627 struct z_candidate *cand = convs->cand;
4628 tree convfn = cand->fn;
4631 /* When converting from an init list we consider explicit
4632 constructors, but actually trying to call one is an error. */
4633 if (DECL_NONCONVERTING_P (convfn))
4635 if (complain & tf_error)
4636 error ("converting to %qT from initializer list would use "
4637 "explicit constructor %qD", totype, convfn);
4639 return error_mark_node;
4642 /* Set user_conv_p on the argument conversions, so rvalue/base
4643 handling knows not to allow any more UDCs. */
4644 for (i = 0; i < cand->num_convs; ++i)
4645 cand->convs[i]->user_conv_p = true;
4647 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
4649 /* If this is a constructor or a function returning an aggr type,
4650 we need to build up a TARGET_EXPR. */
4651 if (DECL_CONSTRUCTOR_P (convfn))
4653 expr = build_cplus_new (totype, expr);
4655 /* Remember that this was list-initialization. */
4656 if (convs->check_narrowing)
4657 TARGET_EXPR_LIST_INIT_P (expr) = true;
4663 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
4665 int nelts = CONSTRUCTOR_NELTS (expr);
4667 expr = integer_zero_node;
4668 else if (nelts == 1)
4669 expr = CONSTRUCTOR_ELT (expr, 0)->value;
4674 if (type_unknown_p (expr))
4675 expr = instantiate_type (totype, expr, complain);
4676 /* Convert a constant to its underlying value, unless we are
4677 about to bind it to a reference, in which case we need to
4678 leave it as an lvalue. */
4681 expr = decl_constant_value (expr);
4682 if (expr == null_node && INTEGRAL_TYPE_P (totype))
4683 /* If __null has been converted to an integer type, we do not
4684 want to warn about uses of EXPR as an integer, rather than
4686 expr = build_int_cst (totype, 0);
4690 /* Call build_user_type_conversion again for the error. */
4691 return build_user_type_conversion
4692 (totype, convs->u.expr, LOOKUP_NORMAL);
4696 /* Conversion to std::initializer_list<T>. */
4697 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
4698 tree new_ctor = build_constructor (init_list_type_node, NULL);
4699 unsigned len = CONSTRUCTOR_NELTS (expr);
4700 tree array, parms, val;
4703 /* Convert all the elements. */
4704 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
4706 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
4707 1, false, false, complain);
4708 if (sub == error_mark_node)
4710 check_narrowing (TREE_TYPE (sub), val);
4711 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
4713 /* Build up the array. */
4714 elttype = cp_build_qualified_type
4715 (elttype, TYPE_QUALS (elttype) | TYPE_QUAL_CONST);
4716 array = build_array_of_n_type (elttype, len);
4717 array = finish_compound_literal (array, new_ctor);
4719 parms = build_tree_list (NULL_TREE, size_int (len));
4720 parms = tree_cons (NULL_TREE, decay_conversion (array), parms);
4721 /* Call the private constructor. */
4722 push_deferring_access_checks (dk_no_check);
4723 new_ctor = build_special_member_call
4724 (NULL_TREE, complete_ctor_identifier, parms, totype, 0, complain);
4725 pop_deferring_access_checks ();
4726 return build_cplus_new (totype, new_ctor);
4730 return get_target_expr (digest_init (totype, expr));
4736 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4737 convs->kind == ck_ref_bind ? -1 : 1,
4738 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
4741 if (expr == error_mark_node)
4742 return error_mark_node;
4744 switch (convs->kind)
4747 expr = convert_bitfield_to_declared_type (expr);
4748 if (! MAYBE_CLASS_TYPE_P (totype))
4750 /* Else fall through. */
4752 if (convs->kind == ck_base && !convs->need_temporary_p)
4754 /* We are going to bind a reference directly to a base-class
4755 subobject of EXPR. */
4756 /* Build an expression for `*((base*) &expr)'. */
4757 expr = cp_build_unary_op (ADDR_EXPR, expr, 0, complain);
4758 expr = convert_to_base (expr, build_pointer_type (totype),
4759 !c_cast_p, /*nonnull=*/true);
4760 expr = cp_build_indirect_ref (expr, "implicit conversion", complain);
4764 /* Copy-initialization where the cv-unqualified version of the source
4765 type is the same class as, or a derived class of, the class of the
4766 destination [is treated as direct-initialization]. [dcl.init] */
4767 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
4768 if (convs->user_conv_p)
4769 /* This conversion is being done in the context of a user-defined
4770 conversion (i.e. the second step of copy-initialization), so
4771 don't allow any more. */
4772 flags |= LOOKUP_NO_CONVERSION;
4773 expr = build_temp (expr, totype, flags, &diag_kind);
4774 if (diag_kind && fn)
4776 if ((complain & tf_error))
4777 emit_diagnostic (diag_kind, input_location, 0,
4778 " initializing argument %P of %qD", argnum, fn);
4779 else if (diag_kind == DK_ERROR)
4780 return error_mark_node;
4782 return build_cplus_new (totype, expr);
4786 tree ref_type = totype;
4788 /* If necessary, create a temporary.
4790 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4791 that need temporaries, even when their types are reference
4792 compatible with the type of reference being bound, so the
4793 upcoming call to cp_build_unary_op (ADDR_EXPR, expr, ...)
4795 if (convs->need_temporary_p
4796 || TREE_CODE (expr) == CONSTRUCTOR
4797 || TREE_CODE (expr) == VA_ARG_EXPR)
4799 tree type = convs->u.next->type;
4800 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4802 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))
4803 && !TYPE_REF_IS_RVALUE (ref_type))
4805 if (complain & tf_error)
4807 /* If the reference is volatile or non-const, we
4808 cannot create a temporary. */
4809 if (lvalue & clk_bitfield)
4810 error ("cannot bind bitfield %qE to %qT",
4812 else if (lvalue & clk_packed)
4813 error ("cannot bind packed field %qE to %qT",
4816 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4818 return error_mark_node;
4820 /* If the source is a packed field, and we must use a copy
4821 constructor, then building the target expr will require
4822 binding the field to the reference parameter to the
4823 copy constructor, and we'll end up with an infinite
4824 loop. If we can use a bitwise copy, then we'll be
4826 if ((lvalue & clk_packed)
4827 && CLASS_TYPE_P (type)
4828 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4830 if (complain & tf_error)
4831 error ("cannot bind packed field %qE to %qT",
4833 return error_mark_node;
4835 if (lvalue & clk_bitfield)
4837 expr = convert_bitfield_to_declared_type (expr);
4838 expr = fold_convert (type, expr);
4840 expr = build_target_expr_with_type (expr, type);
4843 /* Take the address of the thing to which we will bind the
4845 expr = cp_build_unary_op (ADDR_EXPR, expr, 1, complain);
4846 if (expr == error_mark_node)
4847 return error_mark_node;
4849 /* Convert it to a pointer to the type referred to by the
4850 reference. This will adjust the pointer if a derived to
4851 base conversion is being performed. */
4852 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4854 /* Convert the pointer to the desired reference type. */
4855 return build_nop (ref_type, expr);
4859 return decay_conversion (expr);
4862 /* Warn about deprecated conversion if appropriate. */
4863 string_conv_p (totype, expr, 1);
4868 expr = convert_to_base (expr, totype, !c_cast_p,
4870 return build_nop (totype, expr);
4873 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4880 if (convs->check_narrowing)
4881 check_narrowing (totype, expr);
4883 if (issue_conversion_warnings && (complain & tf_warning))
4884 expr = convert_and_check (totype, expr);
4886 expr = convert (totype, expr);
4891 /* Build a call to __builtin_trap. */
4894 call_builtin_trap (void)
4896 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4898 gcc_assert (fn != NULL);
4899 fn = build_call_n (fn, 0);
4903 /* ARG is being passed to a varargs function. Perform any conversions
4904 required. Return the converted value. */
4907 convert_arg_to_ellipsis (tree arg)
4911 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4912 standard conversions are performed. */
4913 arg = decay_conversion (arg);
4916 If the argument has integral or enumeration type that is subject
4917 to the integral promotions (_conv.prom_), or a floating point
4918 type that is subject to the floating point promotion
4919 (_conv.fpprom_), the value of the argument is converted to the
4920 promoted type before the call. */
4921 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4922 && (TYPE_PRECISION (TREE_TYPE (arg))
4923 < TYPE_PRECISION (double_type_node)))
4924 arg = convert_to_real (double_type_node, arg);
4925 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4926 arg = perform_integral_promotions (arg);
4928 arg = require_complete_type (arg);
4930 if (arg != error_mark_node
4931 && !pod_type_p (TREE_TYPE (arg)))
4933 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4934 here and do a bitwise copy, but now cp_expr_size will abort if we
4936 If the call appears in the context of a sizeof expression,
4937 there is no need to emit a warning, since the expression won't be
4938 evaluated. We keep the builtin_trap just as a safety check. */
4939 if (!skip_evaluation)
4940 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4941 "call will abort at runtime", TREE_TYPE (arg));
4942 arg = call_builtin_trap ();
4943 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4950 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4953 build_x_va_arg (tree expr, tree type)
4955 if (processing_template_decl)
4956 return build_min (VA_ARG_EXPR, type, expr);
4958 type = complete_type_or_else (type, NULL_TREE);
4960 if (expr == error_mark_node || !type)
4961 return error_mark_node;
4963 if (! pod_type_p (type))
4965 /* Remove reference types so we don't ICE later on. */
4966 tree type1 = non_reference (type);
4967 /* Undefined behavior [expr.call] 5.2.2/7. */
4968 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4969 "call will abort at runtime", type);
4970 expr = convert (build_pointer_type (type1), null_node);
4971 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4972 call_builtin_trap (), expr);
4973 expr = cp_build_indirect_ref (expr, NULL, tf_warning_or_error);
4977 return build_va_arg (expr, type);
4980 /* TYPE has been given to va_arg. Apply the default conversions which
4981 would have happened when passed via ellipsis. Return the promoted
4982 type, or the passed type if there is no change. */
4985 cxx_type_promotes_to (tree type)
4989 /* Perform the array-to-pointer and function-to-pointer
4991 type = type_decays_to (type);
4993 promote = type_promotes_to (type);
4994 if (same_type_p (type, promote))
5000 /* ARG is a default argument expression being passed to a parameter of
5001 the indicated TYPE, which is a parameter to FN. Do any required
5002 conversions. Return the converted value. */
5004 static GTY(()) VEC(tree,gc) *default_arg_context;
5007 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
5012 /* If the ARG is an unparsed default argument expression, the
5013 conversion cannot be performed. */
5014 if (TREE_CODE (arg) == DEFAULT_ARG)
5016 error ("the default argument for parameter %d of %qD has "
5017 "not yet been parsed",
5019 return error_mark_node;
5022 /* Detect recursion. */
5023 for (i = 0; VEC_iterate (tree, default_arg_context, i, t); ++i)
5026 error ("recursive evaluation of default argument for %q#D", fn);
5027 return error_mark_node;
5029 VEC_safe_push (tree, gc, default_arg_context, fn);
5031 if (fn && DECL_TEMPLATE_INFO (fn))
5032 arg = tsubst_default_argument (fn, type, arg);
5038 The names in the expression are bound, and the semantic
5039 constraints are checked, at the point where the default
5040 expressions appears.
5042 we must not perform access checks here. */
5043 push_deferring_access_checks (dk_no_check);
5044 arg = break_out_target_exprs (arg);
5045 if (TREE_CODE (arg) == CONSTRUCTOR)
5047 arg = digest_init (type, arg);
5048 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
5049 "default argument", fn, parmnum,
5050 tf_warning_or_error);
5054 /* We must make a copy of ARG, in case subsequent processing
5055 alters any part of it. For example, during gimplification a
5056 cast of the form (T) &X::f (where "f" is a member function)
5057 will lead to replacing the PTRMEM_CST for &X::f with a
5058 VAR_DECL. We can avoid the copy for constants, since they
5059 are never modified in place. */
5060 if (!CONSTANT_CLASS_P (arg))
5061 arg = unshare_expr (arg);
5062 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
5063 "default argument", fn, parmnum,
5064 tf_warning_or_error);
5065 arg = convert_for_arg_passing (type, arg);
5067 pop_deferring_access_checks();
5069 VEC_pop (tree, default_arg_context);
5074 /* Returns the type which will really be used for passing an argument of
5078 type_passed_as (tree type)
5080 /* Pass classes with copy ctors by invisible reference. */
5081 if (TREE_ADDRESSABLE (type))
5083 type = build_reference_type (type);
5084 /* There are no other pointers to this temporary. */
5085 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
5087 else if (targetm.calls.promote_prototypes (type)
5088 && INTEGRAL_TYPE_P (type)
5089 && COMPLETE_TYPE_P (type)
5090 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5091 TYPE_SIZE (integer_type_node)))
5092 type = integer_type_node;
5097 /* Actually perform the appropriate conversion. */
5100 convert_for_arg_passing (tree type, tree val)
5104 /* If VAL is a bitfield, then -- since it has already been converted
5105 to TYPE -- it cannot have a precision greater than TYPE.
5107 If it has a smaller precision, we must widen it here. For
5108 example, passing "int f:3;" to a function expecting an "int" will
5109 not result in any conversion before this point.
5111 If the precision is the same we must not risk widening. For
5112 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5113 often have type "int", even though the C++ type for the field is
5114 "long long". If the value is being passed to a function
5115 expecting an "int", then no conversions will be required. But,
5116 if we call convert_bitfield_to_declared_type, the bitfield will
5117 be converted to "long long". */
5118 bitfield_type = is_bitfield_expr_with_lowered_type (val);
5120 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
5121 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
5123 if (val == error_mark_node)
5125 /* Pass classes with copy ctors by invisible reference. */
5126 else if (TREE_ADDRESSABLE (type))
5127 val = build1 (ADDR_EXPR, build_reference_type (type), val);
5128 else if (targetm.calls.promote_prototypes (type)
5129 && INTEGRAL_TYPE_P (type)
5130 && COMPLETE_TYPE_P (type)
5131 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5132 TYPE_SIZE (integer_type_node)))
5133 val = perform_integral_promotions (val);
5134 if (warn_missing_format_attribute)
5136 tree rhstype = TREE_TYPE (val);
5137 const enum tree_code coder = TREE_CODE (rhstype);
5138 const enum tree_code codel = TREE_CODE (type);
5139 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5141 && check_missing_format_attribute (type, rhstype))
5142 warning (OPT_Wmissing_format_attribute,
5143 "argument of function call might be a candidate for a format attribute");
5148 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5149 which no conversions at all should be done. This is true for some
5150 builtins which don't act like normal functions. */
5153 magic_varargs_p (tree fn)
5155 if (DECL_BUILT_IN (fn))
5156 switch (DECL_FUNCTION_CODE (fn))
5158 case BUILT_IN_CLASSIFY_TYPE:
5159 case BUILT_IN_CONSTANT_P:
5160 case BUILT_IN_NEXT_ARG:
5161 case BUILT_IN_VA_START:
5165 return lookup_attribute ("type generic",
5166 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
5172 /* Subroutine of the various build_*_call functions. Overload resolution
5173 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5174 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5175 bitmask of various LOOKUP_* flags which apply to the call itself. */
5178 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
5181 tree args = cand->args;
5182 conversion **convs = cand->convs;
5184 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
5192 bool already_used = false;
5194 /* In a template, there is no need to perform all of the work that
5195 is normally done. We are only interested in the type of the call
5196 expression, i.e., the return type of the function. Any semantic
5197 errors will be deferred until the template is instantiated. */
5198 if (processing_template_decl)
5202 return_type = TREE_TYPE (TREE_TYPE (fn));
5203 expr = build_call_list (return_type, build_addr_func (fn), args);
5204 if (TREE_THIS_VOLATILE (fn) && cfun)
5205 current_function_returns_abnormally = 1;
5206 if (!VOID_TYPE_P (return_type))
5207 require_complete_type (return_type);
5208 return convert_from_reference (expr);
5211 /* Give any warnings we noticed during overload resolution. */
5214 struct candidate_warning *w;
5215 for (w = cand->warnings; w; w = w->next)
5216 joust (cand, w->loser, 1);
5219 /* Make =delete work with SFINAE. */
5220 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
5221 return error_mark_node;
5223 if (DECL_FUNCTION_MEMBER_P (fn))
5225 /* If FN is a template function, two cases must be considered.
5230 template <class T> void f();
5232 template <class T> struct B {
5236 struct C : A, B<int> {
5238 using B<int>::g; // #2
5241 In case #1 where `A::f' is a member template, DECL_ACCESS is
5242 recorded in the primary template but not in its specialization.
5243 We check access of FN using its primary template.
5245 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
5246 because it is a member of class template B, DECL_ACCESS is
5247 recorded in the specialization `B<int>::g'. We cannot use its
5248 primary template because `B<T>::g' and `B<int>::g' may have
5249 different access. */
5250 if (DECL_TEMPLATE_INFO (fn)
5251 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
5252 perform_or_defer_access_check (cand->access_path,
5253 DECL_TI_TEMPLATE (fn), fn);
5255 perform_or_defer_access_check (cand->access_path, fn, fn);
5258 if (args && TREE_CODE (args) != TREE_LIST)
5259 args = build_tree_list (NULL_TREE, args);
5262 /* Find maximum size of vector to hold converted arguments. */
5263 parmlen = list_length (parm);
5264 nargs = list_length (args);
5265 if (parmlen > nargs)
5267 argarray = (tree *) alloca (nargs * sizeof (tree));
5269 /* The implicit parameters to a constructor are not considered by overload
5270 resolution, and must be of the proper type. */
5271 if (DECL_CONSTRUCTOR_P (fn))
5273 argarray[j++] = TREE_VALUE (arg);
5274 arg = TREE_CHAIN (arg);
5275 parm = TREE_CHAIN (parm);
5276 /* We should never try to call the abstract constructor. */
5277 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
5279 if (DECL_HAS_VTT_PARM_P (fn))
5281 argarray[j++] = TREE_VALUE (arg);
5282 arg = TREE_CHAIN (arg);
5283 parm = TREE_CHAIN (parm);
5286 /* Bypass access control for 'this' parameter. */
5287 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
5289 tree parmtype = TREE_VALUE (parm);
5290 tree argtype = TREE_TYPE (TREE_VALUE (arg));
5294 if (convs[i]->bad_p)
5296 if (complain & tf_error)
5297 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
5298 TREE_TYPE (argtype), fn);
5300 return error_mark_node;
5303 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
5304 X is called for an object that is not of type X, or of a type
5305 derived from X, the behavior is undefined.
5307 So we can assume that anything passed as 'this' is non-null, and
5308 optimize accordingly. */
5309 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
5310 /* Convert to the base in which the function was declared. */
5311 gcc_assert (cand->conversion_path != NULL_TREE);
5312 converted_arg = build_base_path (PLUS_EXPR,
5314 cand->conversion_path,
5316 /* Check that the base class is accessible. */
5317 if (!accessible_base_p (TREE_TYPE (argtype),
5318 BINFO_TYPE (cand->conversion_path), true))
5319 error ("%qT is not an accessible base of %qT",
5320 BINFO_TYPE (cand->conversion_path),
5321 TREE_TYPE (argtype));
5322 /* If fn was found by a using declaration, the conversion path
5323 will be to the derived class, not the base declaring fn. We
5324 must convert from derived to base. */
5325 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
5326 TREE_TYPE (parmtype), ba_unique, NULL);
5327 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
5330 argarray[j++] = converted_arg;
5331 parm = TREE_CHAIN (parm);
5332 arg = TREE_CHAIN (arg);
5338 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
5340 tree type = TREE_VALUE (parm);
5344 /* Don't make a copy here if build_call is going to. */
5345 if (conv->kind == ck_rvalue
5346 && COMPLETE_TYPE_P (complete_type (type))
5347 && !TREE_ADDRESSABLE (type))
5348 conv = conv->u.next;
5350 /* Warn about initializer_list deduction that isn't currently in the
5352 if (cxx_dialect > cxx98
5353 && flag_deduce_init_list
5354 && cand->template_decl
5355 && is_std_init_list (non_reference (type)))
5357 tree tmpl = TI_TEMPLATE (cand->template_decl);
5358 tree realparm = DECL_ARGUMENTS (cand->fn);
5363 realparm = TREE_CHAIN (realparm);
5364 patparm = get_pattern_parm (realparm, tmpl);
5366 if (!is_std_init_list (non_reference (TREE_TYPE (patparm))))
5368 pedwarn (input_location, 0, "deducing %qT as %qT",
5369 non_reference (TREE_TYPE (patparm)),
5370 non_reference (type));
5371 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
5372 pedwarn (input_location, 0,
5373 " (you can disable this with -fno-deduce-init-list)");
5377 val = convert_like_with_context
5378 (conv, TREE_VALUE (arg), fn, i - is_method, complain);
5380 val = convert_for_arg_passing (type, val);
5381 if (val == error_mark_node)
5382 return error_mark_node;
5384 argarray[j++] = val;
5387 /* Default arguments */
5388 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
5389 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
5390 TREE_PURPOSE (parm),
5393 for (; arg; arg = TREE_CHAIN (arg))
5395 tree a = TREE_VALUE (arg);
5396 if (magic_varargs_p (fn))
5397 /* Do no conversions for magic varargs. */;
5399 a = convert_arg_to_ellipsis (a);
5403 gcc_assert (j <= nargs);
5406 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
5407 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
5409 /* Avoid actually calling copy constructors and copy assignment operators,
5412 if (! flag_elide_constructors)
5413 /* Do things the hard way. */;
5414 else if (cand->num_convs == 1
5415 && (DECL_COPY_CONSTRUCTOR_P (fn)
5416 || DECL_MOVE_CONSTRUCTOR_P (fn)))
5419 arg = argarray[num_artificial_parms_for (fn)];
5421 /* Pull out the real argument, disregarding const-correctness. */
5423 while (CONVERT_EXPR_P (targ)
5424 || TREE_CODE (targ) == NON_LVALUE_EXPR)
5425 targ = TREE_OPERAND (targ, 0);
5426 if (TREE_CODE (targ) == ADDR_EXPR)
5428 targ = TREE_OPERAND (targ, 0);
5429 if (!same_type_ignoring_top_level_qualifiers_p
5430 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
5439 arg = cp_build_indirect_ref (arg, 0, complain);
5441 if (TREE_CODE (arg) == TARGET_EXPR
5442 && TARGET_EXPR_LIST_INIT_P (arg))
5444 /* Copy-list-initialization doesn't require the copy constructor
5447 /* [class.copy]: the copy constructor is implicitly defined even if
5448 the implementation elided its use. */
5449 else if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
5452 already_used = true;
5455 /* If we're creating a temp and we already have one, don't create a
5456 new one. If we're not creating a temp but we get one, use
5457 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5458 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5459 temp or an INIT_EXPR otherwise. */
5460 if (integer_zerop (TREE_VALUE (args)))
5462 if (TREE_CODE (arg) == TARGET_EXPR)
5464 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5465 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
5467 else if (TREE_CODE (arg) == TARGET_EXPR
5468 || (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn))
5469 && !move_fn_p (fn)))
5471 tree to = stabilize_reference
5472 (cp_build_indirect_ref (TREE_VALUE (args), 0, complain));
5474 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
5478 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
5480 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
5482 tree to = stabilize_reference
5483 (cp_build_indirect_ref (argarray[0], 0, complain));
5484 tree type = TREE_TYPE (to);
5485 tree as_base = CLASSTYPE_AS_BASE (type);
5488 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
5490 arg = cp_build_indirect_ref (arg, 0, complain);
5491 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
5495 /* We must only copy the non-tail padding parts.
5496 Use __builtin_memcpy for the bitwise copy.
5497 FIXME fix 22488 so we can go back to using MODIFY_EXPR
5498 instead of an explicit call to memcpy. */
5500 tree arg0, arg1, arg2, t;
5501 tree test = NULL_TREE;
5503 arg2 = TYPE_SIZE_UNIT (as_base);
5505 arg0 = cp_build_unary_op (ADDR_EXPR, to, 0, complain);
5507 if (!(optimize && flag_tree_ter))
5509 /* When TER is off get_pointer_alignment returns 0, so a call
5510 to __builtin_memcpy is expanded as a call to memcpy, which
5511 is invalid with identical args. When TER is on it is
5512 expanded as a block move, which should be safe. */
5513 arg0 = save_expr (arg0);
5514 arg1 = save_expr (arg1);
5515 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
5517 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
5518 t = build_call_n (t, 3, arg0, arg1, arg2);
5520 t = convert (TREE_TYPE (arg0), t);
5522 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
5523 val = cp_build_indirect_ref (t, 0, complain);
5532 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
5535 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
5538 gcc_assert (binfo && binfo != error_mark_node);
5540 /* Warn about deprecated virtual functions now, since we're about
5541 to throw away the decl. */
5542 if (TREE_DEPRECATED (fn))
5543 warn_deprecated_use (fn);
5545 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
5546 if (TREE_SIDE_EFFECTS (argarray[0]))
5547 argarray[0] = save_expr (argarray[0]);
5548 t = build_pointer_type (TREE_TYPE (fn));
5549 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5550 fn = build_java_interface_fn_ref (fn, argarray[0]);
5552 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
5556 fn = build_addr_func (fn);
5558 return build_cxx_call (fn, nargs, argarray);
5561 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5562 This function performs no overload resolution, conversion, or other
5563 high-level operations. */
5566 build_cxx_call (tree fn, int nargs, tree *argarray)
5570 fn = build_call_a (fn, nargs, argarray);
5572 /* If this call might throw an exception, note that fact. */
5573 fndecl = get_callee_fndecl (fn);
5574 if ((!fndecl || !TREE_NOTHROW (fndecl))
5575 && at_function_scope_p ()
5577 cp_function_chain->can_throw = 1;
5579 /* Check that arguments to builtin functions match the expectations. */
5581 && DECL_BUILT_IN (fndecl)
5582 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
5583 && !check_builtin_function_arguments (fndecl, nargs, argarray))
5584 return error_mark_node;
5586 /* Some built-in function calls will be evaluated at compile-time in
5588 fn = fold_if_not_in_template (fn);
5590 if (VOID_TYPE_P (TREE_TYPE (fn)))
5593 fn = require_complete_type (fn);
5594 if (fn == error_mark_node)
5595 return error_mark_node;
5597 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
5598 fn = build_cplus_new (TREE_TYPE (fn), fn);
5599 return convert_from_reference (fn);
5602 static GTY(()) tree java_iface_lookup_fn;
5604 /* Make an expression which yields the address of the Java interface
5605 method FN. This is achieved by generating a call to libjava's
5606 _Jv_LookupInterfaceMethodIdx(). */
5609 build_java_interface_fn_ref (tree fn, tree instance)
5611 tree lookup_fn, method, idx;
5612 tree klass_ref, iface, iface_ref;
5615 if (!java_iface_lookup_fn)
5617 tree endlink = build_void_list_node ();
5618 tree t = tree_cons (NULL_TREE, ptr_type_node,
5619 tree_cons (NULL_TREE, ptr_type_node,
5620 tree_cons (NULL_TREE, java_int_type_node,
5622 java_iface_lookup_fn
5623 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx",
5624 build_function_type (ptr_type_node, t),
5625 0, NOT_BUILT_IN, NULL, NULL_TREE);
5628 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5629 This is the first entry in the vtable. */
5630 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, 0,
5631 tf_warning_or_error),
5634 /* Get the java.lang.Class pointer for the interface being called. */
5635 iface = DECL_CONTEXT (fn);
5636 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5637 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5638 || DECL_CONTEXT (iface_ref) != iface)
5640 error ("could not find class$ field in java interface type %qT",
5642 return error_mark_node;
5644 iface_ref = build_address (iface_ref);
5645 iface_ref = convert (build_pointer_type (iface), iface_ref);
5647 /* Determine the itable index of FN. */
5649 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5651 if (!DECL_VIRTUAL_P (method))
5657 idx = build_int_cst (NULL_TREE, i);
5659 lookup_fn = build1 (ADDR_EXPR,
5660 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5661 java_iface_lookup_fn);
5662 return build_call_nary (ptr_type_node, lookup_fn,
5663 3, klass_ref, iface_ref, idx);
5666 /* Returns the value to use for the in-charge parameter when making a
5667 call to a function with the indicated NAME.
5669 FIXME:Can't we find a neater way to do this mapping? */
5672 in_charge_arg_for_name (tree name)
5674 if (name == base_ctor_identifier
5675 || name == base_dtor_identifier)
5676 return integer_zero_node;
5677 else if (name == complete_ctor_identifier)
5678 return integer_one_node;
5679 else if (name == complete_dtor_identifier)
5680 return integer_two_node;
5681 else if (name == deleting_dtor_identifier)
5682 return integer_three_node;
5684 /* This function should only be called with one of the names listed
5690 /* Build a call to a constructor, destructor, or an assignment
5691 operator for INSTANCE, an expression with class type. NAME
5692 indicates the special member function to call; ARGS are the
5693 arguments. BINFO indicates the base of INSTANCE that is to be
5694 passed as the `this' parameter to the member function called.
5696 FLAGS are the LOOKUP_* flags to use when processing the call.
5698 If NAME indicates a complete object constructor, INSTANCE may be
5699 NULL_TREE. In this case, the caller will call build_cplus_new to
5700 store the newly constructed object into a VAR_DECL. */
5703 build_special_member_call (tree instance, tree name, tree args,
5704 tree binfo, int flags, tsubst_flags_t complain)
5707 /* The type of the subobject to be constructed or destroyed. */
5710 gcc_assert (name == complete_ctor_identifier
5711 || name == base_ctor_identifier
5712 || name == complete_dtor_identifier
5713 || name == base_dtor_identifier
5714 || name == deleting_dtor_identifier
5715 || name == ansi_assopname (NOP_EXPR));
5718 /* Resolve the name. */
5719 if (!complete_type_or_else (binfo, NULL_TREE))
5720 return error_mark_node;
5722 binfo = TYPE_BINFO (binfo);
5725 gcc_assert (binfo != NULL_TREE);
5727 class_type = BINFO_TYPE (binfo);
5729 /* Handle the special case where INSTANCE is NULL_TREE. */
5730 if (name == complete_ctor_identifier && !instance)
5732 instance = build_int_cst (build_pointer_type (class_type), 0);
5733 instance = build1 (INDIRECT_REF, class_type, instance);
5737 if (name == complete_dtor_identifier
5738 || name == base_dtor_identifier
5739 || name == deleting_dtor_identifier)
5740 gcc_assert (args == NULL_TREE);
5742 /* Convert to the base class, if necessary. */
5743 if (!same_type_ignoring_top_level_qualifiers_p
5744 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5746 if (name != ansi_assopname (NOP_EXPR))
5747 /* For constructors and destructors, either the base is
5748 non-virtual, or it is virtual but we are doing the
5749 conversion from a constructor or destructor for the
5750 complete object. In either case, we can convert
5752 instance = convert_to_base_statically (instance, binfo);
5754 /* However, for assignment operators, we must convert
5755 dynamically if the base is virtual. */
5756 instance = build_base_path (PLUS_EXPR, instance,
5757 binfo, /*nonnull=*/1);
5761 gcc_assert (instance != NULL_TREE);
5763 fns = lookup_fnfields (binfo, name, 1);
5765 /* When making a call to a constructor or destructor for a subobject
5766 that uses virtual base classes, pass down a pointer to a VTT for
5768 if ((name == base_ctor_identifier
5769 || name == base_dtor_identifier)
5770 && CLASSTYPE_VBASECLASSES (class_type))
5775 /* If the current function is a complete object constructor
5776 or destructor, then we fetch the VTT directly.
5777 Otherwise, we look it up using the VTT we were given. */
5778 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5779 vtt = decay_conversion (vtt);
5780 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5781 build2 (EQ_EXPR, boolean_type_node,
5782 current_in_charge_parm, integer_zero_node),
5785 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5786 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
5787 BINFO_SUBVTT_INDEX (binfo));
5789 args = tree_cons (NULL_TREE, sub_vtt, args);
5792 return build_new_method_call (instance, fns, args,
5793 TYPE_BINFO (BINFO_TYPE (binfo)),
5798 /* Return the NAME, as a C string. The NAME indicates a function that
5799 is a member of TYPE. *FREE_P is set to true if the caller must
5800 free the memory returned.
5802 Rather than go through all of this, we should simply set the names
5803 of constructors and destructors appropriately, and dispense with
5804 ctor_identifier, dtor_identifier, etc. */
5807 name_as_c_string (tree name, tree type, bool *free_p)
5811 /* Assume that we will not allocate memory. */
5813 /* Constructors and destructors are special. */
5814 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5817 = CONST_CAST (char *, IDENTIFIER_POINTER (constructor_name (type)));
5818 /* For a destructor, add the '~'. */
5819 if (name == complete_dtor_identifier
5820 || name == base_dtor_identifier
5821 || name == deleting_dtor_identifier)
5823 pretty_name = concat ("~", pretty_name, NULL);
5824 /* Remember that we need to free the memory allocated. */
5828 else if (IDENTIFIER_TYPENAME_P (name))
5830 pretty_name = concat ("operator ",
5831 type_as_string (TREE_TYPE (name),
5832 TFF_PLAIN_IDENTIFIER),
5834 /* Remember that we need to free the memory allocated. */
5838 pretty_name = CONST_CAST (char *, IDENTIFIER_POINTER (name));
5843 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5844 be set, upon return, to the function called. */
5847 build_new_method_call (tree instance, tree fns, tree args,
5848 tree conversion_path, int flags,
5849 tree *fn_p, tsubst_flags_t complain)
5851 struct z_candidate *candidates = 0, *cand;
5852 tree explicit_targs = NULL_TREE;
5853 tree basetype = NULL_TREE;
5856 tree mem_args = NULL_TREE, instance_ptr;
5862 int template_only = 0;
5869 gcc_assert (instance != NULL_TREE);
5871 /* We don't know what function we're going to call, yet. */
5875 if (error_operand_p (instance)
5876 || error_operand_p (fns)
5877 || args == error_mark_node)
5878 return error_mark_node;
5880 if (!BASELINK_P (fns))
5882 if (complain & tf_error)
5883 error ("call to non-function %qD", fns);
5884 return error_mark_node;
5887 orig_instance = instance;
5891 /* Dismantle the baselink to collect all the information we need. */
5892 if (!conversion_path)
5893 conversion_path = BASELINK_BINFO (fns);
5894 access_binfo = BASELINK_ACCESS_BINFO (fns);
5895 optype = BASELINK_OPTYPE (fns);
5896 fns = BASELINK_FUNCTIONS (fns);
5897 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5899 explicit_targs = TREE_OPERAND (fns, 1);
5900 fns = TREE_OPERAND (fns, 0);
5903 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5904 || TREE_CODE (fns) == TEMPLATE_DECL
5905 || TREE_CODE (fns) == OVERLOAD);
5906 fn = get_first_fn (fns);
5907 name = DECL_NAME (fn);
5909 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5910 gcc_assert (CLASS_TYPE_P (basetype));
5912 if (processing_template_decl)
5914 instance = build_non_dependent_expr (instance);
5915 args = build_non_dependent_args (orig_args);
5918 /* The USER_ARGS are the arguments we will display to users if an
5919 error occurs. The USER_ARGS should not include any
5920 compiler-generated arguments. The "this" pointer hasn't been
5921 added yet. However, we must remove the VTT pointer if this is a
5922 call to a base-class constructor or destructor. */
5924 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5926 /* Callers should explicitly indicate whether they want to construct
5927 the complete object or just the part without virtual bases. */
5928 gcc_assert (name != ctor_identifier);
5929 /* Similarly for destructors. */
5930 gcc_assert (name != dtor_identifier);
5931 /* Remove the VTT pointer, if present. */
5932 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5933 && CLASSTYPE_VBASECLASSES (basetype))
5934 user_args = TREE_CHAIN (user_args);
5937 /* Process the argument list. */
5938 args = resolve_args (args);
5939 if (args == error_mark_node)
5940 return error_mark_node;
5942 instance_ptr = build_this (instance);
5944 /* It's OK to call destructors and constructors on cv-qualified objects.
5945 Therefore, convert the INSTANCE_PTR to the unqualified type, if
5947 if (DECL_DESTRUCTOR_P (fn)
5948 || DECL_CONSTRUCTOR_P (fn))
5950 tree type = build_pointer_type (basetype);
5951 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5952 instance_ptr = build_nop (type, instance_ptr);
5954 if (DECL_DESTRUCTOR_P (fn))
5955 name = complete_dtor_identifier;
5957 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
5958 initializer, not T({ }). If the type doesn't have a list ctor,
5959 break apart the list into separate ctor args. */
5960 if (DECL_CONSTRUCTOR_P (fn) && args
5961 && BRACE_ENCLOSED_INITIALIZER_P (TREE_VALUE (args))
5962 && CONSTRUCTOR_IS_DIRECT_INIT (TREE_VALUE (args))
5963 && !TYPE_HAS_LIST_CTOR (basetype))
5965 gcc_assert (TREE_CHAIN (args) == NULL_TREE);
5966 args = ctor_to_list (TREE_VALUE (args));
5969 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5970 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5972 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5973 p = conversion_obstack_alloc (0);
5975 for (fn = fns; fn; fn = OVL_NEXT (fn))
5977 tree t = OVL_CURRENT (fn);
5980 /* We can end up here for copy-init of same or base class. */
5981 if ((flags & LOOKUP_ONLYCONVERTING)
5982 && DECL_NONCONVERTING_P (t))
5985 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5986 this_arglist = mem_args;
5988 this_arglist = args;
5990 if (TREE_CODE (t) == TEMPLATE_DECL)
5991 /* A member template. */
5992 add_template_candidate (&candidates, t,
5995 this_arglist, optype,
6000 else if (! template_only)
6001 add_function_candidate (&candidates, t,
6009 candidates = splice_viable (candidates, pedantic, &any_viable_p);
6012 if (complain & tf_error)
6014 if (!COMPLETE_TYPE_P (basetype))
6015 cxx_incomplete_type_error (instance_ptr, basetype);
6021 pretty_name = name_as_c_string (name, basetype, &free_p);
6022 error ("no matching function for call to %<%T::%s(%A)%#V%>",
6023 basetype, pretty_name, user_args,
6024 TREE_TYPE (TREE_TYPE (instance_ptr)));
6028 print_z_candidates (candidates);
6030 call = error_mark_node;
6034 cand = tourney (candidates);
6040 if (complain & tf_error)
6042 pretty_name = name_as_c_string (name, basetype, &free_p);
6043 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
6045 print_z_candidates (candidates);
6049 call = error_mark_node;
6055 if (!(flags & LOOKUP_NONVIRTUAL)
6056 && DECL_PURE_VIRTUAL_P (fn)
6057 && instance == current_class_ref
6058 && (DECL_CONSTRUCTOR_P (current_function_decl)
6059 || DECL_DESTRUCTOR_P (current_function_decl))
6060 && (complain & tf_warning))
6061 /* This is not an error, it is runtime undefined
6063 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
6064 "abstract virtual %q#D called from constructor"
6065 : "abstract virtual %q#D called from destructor"),
6068 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
6069 && is_dummy_object (instance_ptr))
6071 if (complain & tf_error)
6072 error ("cannot call member function %qD without object",
6074 call = error_mark_node;
6078 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
6079 && resolves_to_fixed_type_p (instance, 0))
6080 flags |= LOOKUP_NONVIRTUAL;
6081 /* Now we know what function is being called. */
6084 /* Build the actual CALL_EXPR. */
6085 call = build_over_call (cand, flags, complain);
6086 /* In an expression of the form `a->f()' where `f' turns
6087 out to be a static member function, `a' is
6088 none-the-less evaluated. */
6089 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
6090 && !is_dummy_object (instance_ptr)
6091 && TREE_SIDE_EFFECTS (instance_ptr))
6092 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
6093 instance_ptr, call);
6094 else if (call != error_mark_node
6095 && DECL_DESTRUCTOR_P (cand->fn)
6096 && !VOID_TYPE_P (TREE_TYPE (call)))
6097 /* An explicit call of the form "x->~X()" has type
6098 "void". However, on platforms where destructors
6099 return "this" (i.e., those where
6100 targetm.cxx.cdtor_returns_this is true), such calls
6101 will appear to have a return value of pointer type
6102 to the low-level call machinery. We do not want to
6103 change the low-level machinery, since we want to be
6104 able to optimize "delete f()" on such platforms as
6105 "operator delete(~X(f()))" (rather than generating
6106 "t = f(), ~X(t), operator delete (t)"). */
6107 call = build_nop (void_type_node, call);
6112 if (processing_template_decl && call != error_mark_node)
6114 bool cast_to_void = false;
6116 if (TREE_CODE (call) == COMPOUND_EXPR)
6117 call = TREE_OPERAND (call, 1);
6118 else if (TREE_CODE (call) == NOP_EXPR)
6120 cast_to_void = true;
6121 call = TREE_OPERAND (call, 0);
6123 if (TREE_CODE (call) == INDIRECT_REF)
6124 call = TREE_OPERAND (call, 0);
6125 call = (build_min_non_dep_call_list
6127 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
6128 orig_instance, orig_fns, NULL_TREE),
6130 call = convert_from_reference (call);
6132 call = build_nop (void_type_node, call);
6135 /* Free all the conversions we allocated. */
6136 obstack_free (&conversion_obstack, p);
6141 /* Returns true iff standard conversion sequence ICS1 is a proper
6142 subsequence of ICS2. */
6145 is_subseq (conversion *ics1, conversion *ics2)
6147 /* We can assume that a conversion of the same code
6148 between the same types indicates a subsequence since we only get
6149 here if the types we are converting from are the same. */
6151 while (ics1->kind == ck_rvalue
6152 || ics1->kind == ck_lvalue)
6153 ics1 = ics1->u.next;
6157 while (ics2->kind == ck_rvalue
6158 || ics2->kind == ck_lvalue)
6159 ics2 = ics2->u.next;
6161 if (ics2->kind == ck_user
6162 || ics2->kind == ck_ambig
6163 || ics2->kind == ck_identity)
6164 /* At this point, ICS1 cannot be a proper subsequence of
6165 ICS2. We can get a USER_CONV when we are comparing the
6166 second standard conversion sequence of two user conversion
6170 ics2 = ics2->u.next;
6172 if (ics2->kind == ics1->kind
6173 && same_type_p (ics2->type, ics1->type)
6174 && same_type_p (ics2->u.next->type,
6175 ics1->u.next->type))
6180 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
6181 be any _TYPE nodes. */
6184 is_properly_derived_from (tree derived, tree base)
6186 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
6189 /* We only allow proper derivation here. The DERIVED_FROM_P macro
6190 considers every class derived from itself. */
6191 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
6192 && DERIVED_FROM_P (base, derived));
6195 /* We build the ICS for an implicit object parameter as a pointer
6196 conversion sequence. However, such a sequence should be compared
6197 as if it were a reference conversion sequence. If ICS is the
6198 implicit conversion sequence for an implicit object parameter,
6199 modify it accordingly. */
6202 maybe_handle_implicit_object (conversion **ics)
6206 /* [over.match.funcs]
6208 For non-static member functions, the type of the
6209 implicit object parameter is "reference to cv X"
6210 where X is the class of which the function is a
6211 member and cv is the cv-qualification on the member
6212 function declaration. */
6213 conversion *t = *ics;
6214 tree reference_type;
6216 /* The `this' parameter is a pointer to a class type. Make the
6217 implicit conversion talk about a reference to that same class
6219 reference_type = TREE_TYPE (t->type);
6220 reference_type = build_reference_type (reference_type);
6222 if (t->kind == ck_qual)
6224 if (t->kind == ck_ptr)
6226 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
6227 t = direct_reference_binding (reference_type, t);
6229 t->rvaluedness_matches_p = 0;
6234 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
6235 and return the initial reference binding conversion. Otherwise,
6236 leave *ICS unchanged and return NULL. */
6239 maybe_handle_ref_bind (conversion **ics)
6241 if ((*ics)->kind == ck_ref_bind)
6243 conversion *old_ics = *ics;
6244 *ics = old_ics->u.next;
6245 (*ics)->user_conv_p = old_ics->user_conv_p;
6246 (*ics)->bad_p = old_ics->bad_p;
6253 /* Compare two implicit conversion sequences according to the rules set out in
6254 [over.ics.rank]. Return values:
6256 1: ics1 is better than ics2
6257 -1: ics2 is better than ics1
6258 0: ics1 and ics2 are indistinguishable */
6261 compare_ics (conversion *ics1, conversion *ics2)
6267 tree deref_from_type1 = NULL_TREE;
6268 tree deref_from_type2 = NULL_TREE;
6269 tree deref_to_type1 = NULL_TREE;
6270 tree deref_to_type2 = NULL_TREE;
6271 conversion_rank rank1, rank2;
6273 /* REF_BINDING is nonzero if the result of the conversion sequence
6274 is a reference type. In that case REF_CONV is the reference
6275 binding conversion. */
6276 conversion *ref_conv1;
6277 conversion *ref_conv2;
6279 /* Handle implicit object parameters. */
6280 maybe_handle_implicit_object (&ics1);
6281 maybe_handle_implicit_object (&ics2);
6283 /* Handle reference parameters. */
6284 ref_conv1 = maybe_handle_ref_bind (&ics1);
6285 ref_conv2 = maybe_handle_ref_bind (&ics2);
6287 /* List-initialization sequence L1 is a better conversion sequence than
6288 list-initialization sequence L2 if L1 converts to
6289 std::initializer_list<X> for some X and L2 does not. */
6290 if (ics1->kind == ck_list && ics2->kind != ck_list)
6292 if (ics2->kind == ck_list && ics1->kind != ck_list)
6297 When comparing the basic forms of implicit conversion sequences (as
6298 defined in _over.best.ics_)
6300 --a standard conversion sequence (_over.ics.scs_) is a better
6301 conversion sequence than a user-defined conversion sequence
6302 or an ellipsis conversion sequence, and
6304 --a user-defined conversion sequence (_over.ics.user_) is a
6305 better conversion sequence than an ellipsis conversion sequence
6306 (_over.ics.ellipsis_). */
6307 rank1 = CONVERSION_RANK (ics1);
6308 rank2 = CONVERSION_RANK (ics2);
6312 else if (rank1 < rank2)
6315 if (rank1 == cr_bad)
6317 /* XXX Isn't this an extension? */
6318 /* Both ICS are bad. We try to make a decision based on what
6319 would have happened if they'd been good. */
6320 if (ics1->user_conv_p > ics2->user_conv_p
6321 || ics1->rank > ics2->rank)
6323 else if (ics1->user_conv_p < ics2->user_conv_p
6324 || ics1->rank < ics2->rank)
6327 /* We couldn't make up our minds; try to figure it out below. */
6330 if (ics1->ellipsis_p)
6331 /* Both conversions are ellipsis conversions. */
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"