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
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 {
60 /* The rank of the conversion. Order of the enumerals matters; better
61 conversions should come earlier in the list. */
63 typedef enum conversion_rank {
74 /* An implicit conversion sequence, in the sense of [over.best.ics].
75 The first conversion to be performed is at the end of the chain.
76 That conversion is always a cr_identity conversion. */
78 typedef struct conversion conversion;
80 /* The kind of conversion represented by this step. */
82 /* The rank of this conversion. */
84 BOOL_BITFIELD user_conv_p : 1;
85 BOOL_BITFIELD ellipsis_p : 1;
86 BOOL_BITFIELD this_p : 1;
87 BOOL_BITFIELD bad_p : 1;
88 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
89 temporary should be created to hold the result of the
91 BOOL_BITFIELD need_temporary_p : 1;
92 /* If KIND is ck_identity or ck_base_conv, true to indicate that the
93 copy constructor must be accessible, even though it is not being
95 BOOL_BITFIELD check_copy_constructor_p : 1;
96 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
97 from a pointer-to-derived to pointer-to-base is being performed. */
98 BOOL_BITFIELD base_p : 1;
99 /* If KIND is ck_ref_bind, true when either an lvalue reference is
100 being bound to an lvalue expression or an rvalue reference is
101 being bound to an rvalue expression. */
102 BOOL_BITFIELD rvaluedness_matches_p: 1;
103 /* The type of the expression resulting from the conversion. */
106 /* The next conversion in the chain. Since the conversions are
107 arranged from outermost to innermost, the NEXT conversion will
108 actually be performed before this conversion. This variant is
109 used only when KIND is neither ck_identity nor ck_ambig. */
111 /* The expression at the beginning of the conversion chain. This
112 variant is used only if KIND is ck_identity or ck_ambig. */
115 /* The function candidate corresponding to this conversion
116 sequence. This field is only used if KIND is ck_user. */
117 struct z_candidate *cand;
120 #define CONVERSION_RANK(NODE) \
121 ((NODE)->bad_p ? cr_bad \
122 : (NODE)->ellipsis_p ? cr_ellipsis \
123 : (NODE)->user_conv_p ? cr_user \
126 static struct obstack conversion_obstack;
127 static bool conversion_obstack_initialized;
129 static struct z_candidate * tourney (struct z_candidate *);
130 static int equal_functions (tree, tree);
131 static int joust (struct z_candidate *, struct z_candidate *, bool);
132 static int compare_ics (conversion *, conversion *);
133 static tree build_over_call (struct z_candidate *, int);
134 static tree build_java_interface_fn_ref (tree, tree);
135 #define convert_like(CONV, EXPR) \
136 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
137 /*issue_conversion_warnings=*/true, \
139 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
140 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
141 /*issue_conversion_warnings=*/true, \
143 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
145 static void op_error (enum tree_code, enum tree_code, tree, tree,
147 static tree build_object_call (tree, tree);
148 static tree resolve_args (tree);
149 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
150 static void print_z_candidate (const char *, struct z_candidate *);
151 static void print_z_candidates (struct z_candidate *);
152 static tree build_this (tree);
153 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
154 static bool any_strictly_viable (struct z_candidate *);
155 static struct z_candidate *add_template_candidate
156 (struct z_candidate **, tree, tree, tree, tree, tree,
157 tree, tree, int, unification_kind_t);
158 static struct z_candidate *add_template_candidate_real
159 (struct z_candidate **, tree, tree, tree, tree, tree,
160 tree, tree, int, tree, unification_kind_t);
161 static struct z_candidate *add_template_conv_candidate
162 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
163 static void add_builtin_candidates
164 (struct z_candidate **, enum tree_code, enum tree_code,
166 static void add_builtin_candidate
167 (struct z_candidate **, enum tree_code, enum tree_code,
168 tree, tree, tree, tree *, tree *, int);
169 static bool is_complete (tree);
170 static void build_builtin_candidate
171 (struct z_candidate **, tree, tree, tree, tree *, tree *,
173 static struct z_candidate *add_conv_candidate
174 (struct z_candidate **, tree, tree, tree, tree, tree);
175 static struct z_candidate *add_function_candidate
176 (struct z_candidate **, tree, tree, tree, tree, tree, int);
177 static conversion *implicit_conversion (tree, tree, tree, bool, int);
178 static conversion *standard_conversion (tree, tree, tree, bool, int);
179 static conversion *reference_binding (tree, tree, tree, bool, int);
180 static conversion *build_conv (conversion_kind, tree, conversion *);
181 static bool is_subseq (conversion *, conversion *);
182 static conversion *maybe_handle_ref_bind (conversion **);
183 static void maybe_handle_implicit_object (conversion **);
184 static struct z_candidate *add_candidate
185 (struct z_candidate **, tree, tree, size_t,
186 conversion **, tree, tree, int);
187 static tree source_type (conversion *);
188 static void add_warning (struct z_candidate *, struct z_candidate *);
189 static bool reference_related_p (tree, tree);
190 static bool reference_compatible_p (tree, tree);
191 static conversion *convert_class_to_reference (tree, tree, tree);
192 static conversion *direct_reference_binding (tree, conversion *);
193 static bool promoted_arithmetic_type_p (tree);
194 static conversion *conditional_conversion (tree, tree);
195 static char *name_as_c_string (tree, tree, bool *);
196 static tree call_builtin_trap (void);
197 static tree prep_operand (tree);
198 static void add_candidates (tree, tree, tree, bool, tree, tree,
199 int, struct z_candidate **);
200 static conversion *merge_conversion_sequences (conversion *, conversion *);
201 static bool magic_varargs_p (tree);
202 typedef void (*diagnostic_fn_t) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
203 static tree build_temp (tree, tree, int, diagnostic_fn_t *);
204 static void check_constructor_callable (tree, tree);
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 ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
223 || (TREE_CODE (basetype) == ENUMERAL_TYPE
224 && name == TYPE_IDENTIFIER (basetype)))
227 name = get_type_value (name);
233 template <class T> struct S { ~S(); };
237 NAME will be a class template. */
238 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
244 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
247 /* We want the address of a function or method. We avoid creating a
248 pointer-to-member function. */
251 build_addr_func (tree function)
253 tree type = TREE_TYPE (function);
255 /* We have to do these by hand to avoid real pointer to member
257 if (TREE_CODE (type) == METHOD_TYPE)
259 if (TREE_CODE (function) == OFFSET_REF)
261 tree object = build_address (TREE_OPERAND (function, 0));
262 return get_member_function_from_ptrfunc (&object,
263 TREE_OPERAND (function, 1));
265 function = build_address (function);
268 function = decay_conversion (function);
273 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
274 POINTER_TYPE to those. Note, pointer to member function types
275 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
276 two variants. build_call_a is the primitive taking an array of
277 arguments, while build_call_n is a wrapper that handles varargs. */
280 build_call_n (tree function, int n, ...)
283 return build_call_a (function, 0, NULL);
286 tree *argarray = (tree *) alloca (n * sizeof (tree));
291 for (i = 0; i < n; i++)
292 argarray[i] = va_arg (ap, tree);
294 return build_call_a (function, n, argarray);
299 build_call_a (tree function, int n, tree *argarray)
301 int is_constructor = 0;
308 function = build_addr_func (function);
310 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
311 fntype = TREE_TYPE (TREE_TYPE (function));
312 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
313 || TREE_CODE (fntype) == METHOD_TYPE);
314 result_type = TREE_TYPE (fntype);
316 if (TREE_CODE (function) == ADDR_EXPR
317 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
319 decl = TREE_OPERAND (function, 0);
320 if (!TREE_USED (decl))
322 /* We invoke build_call directly for several library
323 functions. These may have been declared normally if
324 we're building libgcc, so we can't just check
326 gcc_assert (DECL_ARTIFICIAL (decl)
327 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
335 /* We check both the decl and the type; a function may be known not to
336 throw without being declared throw(). */
337 nothrow = ((decl && TREE_NOTHROW (decl))
338 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
340 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
341 current_function_returns_abnormally = 1;
343 if (decl && TREE_DEPRECATED (decl))
344 warn_deprecated_use (decl);
345 require_complete_eh_spec_types (fntype, decl);
347 if (decl && DECL_CONSTRUCTOR_P (decl))
350 /* Don't pass empty class objects by value. This is useful
351 for tags in STL, which are used to control overload resolution.
352 We don't need to handle other cases of copying empty classes. */
353 if (! decl || ! DECL_BUILT_IN (decl))
354 for (i = 0; i < n; i++)
355 if (is_empty_class (TREE_TYPE (argarray[i]))
356 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
358 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
359 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
363 function = build_call_array (result_type, function, n, argarray);
364 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
365 TREE_NOTHROW (function) = nothrow;
370 /* Build something of the form ptr->method (args)
371 or object.method (args). This can also build
372 calls to constructors, and find friends.
374 Member functions always take their class variable
377 INSTANCE is a class instance.
379 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
381 PARMS help to figure out what that NAME really refers to.
383 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
384 down to the real instance type to use for access checking. We need this
385 information to get protected accesses correct.
387 FLAGS is the logical disjunction of zero or more LOOKUP_
388 flags. See cp-tree.h for more info.
390 If this is all OK, calls build_function_call with the resolved
393 This function must also handle being called to perform
394 initialization, promotion/coercion of arguments, and
395 instantiation of default parameters.
397 Note that NAME may refer to an instance variable name. If
398 `operator()()' is defined for the type of that field, then we return
401 /* New overloading code. */
403 typedef struct z_candidate z_candidate;
405 typedef struct candidate_warning candidate_warning;
406 struct candidate_warning {
408 candidate_warning *next;
412 /* The FUNCTION_DECL that will be called if this candidate is
413 selected by overload resolution. */
415 /* The arguments to use when calling this function. */
417 /* The implicit conversion sequences for each of the arguments to
420 /* The number of implicit conversion sequences. */
422 /* If FN is a user-defined conversion, the standard conversion
423 sequence from the type returned by FN to the desired destination
425 conversion *second_conv;
427 /* If FN is a member function, the binfo indicating the path used to
428 qualify the name of FN at the call site. This path is used to
429 determine whether or not FN is accessible if it is selected by
430 overload resolution. The DECL_CONTEXT of FN will always be a
431 (possibly improper) base of this binfo. */
433 /* If FN is a non-static member function, the binfo indicating the
434 subobject to which the `this' pointer should be converted if FN
435 is selected by overload resolution. The type pointed to the by
436 the `this' pointer must correspond to the most derived class
437 indicated by the CONVERSION_PATH. */
438 tree conversion_path;
440 candidate_warning *warnings;
444 /* Returns true iff T is a null pointer constant in the sense of
448 null_ptr_cst_p (tree t)
452 A null pointer constant is an integral constant expression
453 (_expr.const_) rvalue of integer type that evaluates to zero. */
454 t = integral_constant_value (t);
457 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t))
460 if (!TREE_OVERFLOW (t))
466 /* Returns nonzero if PARMLIST consists of only default parms and/or
470 sufficient_parms_p (const_tree parmlist)
472 for (; parmlist && parmlist != void_list_node;
473 parmlist = TREE_CHAIN (parmlist))
474 if (!TREE_PURPOSE (parmlist))
479 /* Allocate N bytes of memory from the conversion obstack. The memory
480 is zeroed before being returned. */
483 conversion_obstack_alloc (size_t n)
486 if (!conversion_obstack_initialized)
488 gcc_obstack_init (&conversion_obstack);
489 conversion_obstack_initialized = true;
491 p = obstack_alloc (&conversion_obstack, n);
496 /* Dynamically allocate a conversion. */
499 alloc_conversion (conversion_kind kind)
502 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
507 #ifdef ENABLE_CHECKING
509 /* Make sure that all memory on the conversion obstack has been
513 validate_conversion_obstack (void)
515 if (conversion_obstack_initialized)
516 gcc_assert ((obstack_next_free (&conversion_obstack)
517 == obstack_base (&conversion_obstack)));
520 #endif /* ENABLE_CHECKING */
522 /* Dynamically allocate an array of N conversions. */
525 alloc_conversions (size_t n)
527 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
531 build_conv (conversion_kind code, tree type, conversion *from)
534 conversion_rank rank = CONVERSION_RANK (from);
536 /* We can't use buildl1 here because CODE could be USER_CONV, which
537 takes two arguments. In that case, the caller is responsible for
538 filling in the second argument. */
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 /* Build a representation of the identity conversion from EXPR to
569 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
572 build_identity_conv (tree type, tree expr)
576 c = alloc_conversion (ck_identity);
583 /* Converting from EXPR to TYPE was ambiguous in the sense that there
584 were multiple user-defined conversions to accomplish the job.
585 Build a conversion that indicates that ambiguity. */
588 build_ambiguous_conv (tree type, tree expr)
592 c = alloc_conversion (ck_ambig);
600 strip_top_quals (tree t)
602 if (TREE_CODE (t) == ARRAY_TYPE)
604 return cp_build_qualified_type (t, 0);
607 /* Returns the standard conversion path (see [conv]) from type FROM to type
608 TO, if any. For proper handling of null pointer constants, you must
609 also pass the expression EXPR to convert from. If C_CAST_P is true,
610 this conversion is coming from a C-style cast. */
613 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
616 enum tree_code fcode, tcode;
618 bool fromref = false;
620 to = non_reference (to);
621 if (TREE_CODE (from) == REFERENCE_TYPE)
624 from = TREE_TYPE (from);
626 to = strip_top_quals (to);
627 from = strip_top_quals (from);
629 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
630 && expr && type_unknown_p (expr))
632 expr = instantiate_type (to, expr, tf_conv);
633 if (expr == error_mark_node)
635 from = TREE_TYPE (expr);
638 fcode = TREE_CODE (from);
639 tcode = TREE_CODE (to);
641 conv = build_identity_conv (from, expr);
642 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
644 from = type_decays_to (from);
645 fcode = TREE_CODE (from);
646 conv = build_conv (ck_lvalue, from, conv);
648 else if (fromref || (expr && lvalue_p (expr)))
653 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
656 from = strip_top_quals (bitfield_type);
657 fcode = TREE_CODE (from);
660 conv = build_conv (ck_rvalue, from, conv);
663 /* Allow conversion between `__complex__' data types. */
664 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
666 /* The standard conversion sequence to convert FROM to TO is
667 the standard conversion sequence to perform componentwise
669 conversion *part_conv = standard_conversion
670 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
674 conv = build_conv (part_conv->kind, to, conv);
675 conv->rank = part_conv->rank;
683 if (same_type_p (from, to))
686 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
687 && expr && null_ptr_cst_p (expr))
688 conv = build_conv (ck_std, to, conv);
689 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
690 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
692 /* For backwards brain damage compatibility, allow interconversion of
693 pointers and integers with a pedwarn. */
694 conv = build_conv (ck_std, to, conv);
697 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
699 /* For backwards brain damage compatibility, allow interconversion of
700 enums and integers with a pedwarn. */
701 conv = build_conv (ck_std, to, conv);
704 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
705 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
710 if (tcode == POINTER_TYPE
711 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
714 else if (VOID_TYPE_P (TREE_TYPE (to))
715 && !TYPE_PTRMEM_P (from)
716 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
718 from = build_pointer_type
719 (cp_build_qualified_type (void_type_node,
720 cp_type_quals (TREE_TYPE (from))));
721 conv = build_conv (ck_ptr, from, conv);
723 else if (TYPE_PTRMEM_P (from))
725 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
726 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
728 if (DERIVED_FROM_P (fbase, tbase)
729 && (same_type_ignoring_top_level_qualifiers_p
730 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
731 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
733 from = build_ptrmem_type (tbase,
734 TYPE_PTRMEM_POINTED_TO_TYPE (from));
735 conv = build_conv (ck_pmem, from, conv);
737 else if (!same_type_p (fbase, tbase))
740 else if (IS_AGGR_TYPE (TREE_TYPE (from))
741 && IS_AGGR_TYPE (TREE_TYPE (to))
744 An rvalue of type "pointer to cv D," where D is a
745 class type, can be converted to an rvalue of type
746 "pointer to cv B," where B is a base class (clause
747 _class.derived_) of D. If B is an inaccessible
748 (clause _class.access_) or ambiguous
749 (_class.member.lookup_) base class of D, a program
750 that necessitates this conversion is ill-formed.
751 Therefore, we use DERIVED_FROM_P, and do not check
752 access or uniqueness. */
753 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))
754 /* If FROM is not yet complete, then we must be parsing
755 the body of a class. We know what's derived from
756 what, but we can't actually perform a
757 derived-to-base conversion. For example, in:
759 struct D : public B {
760 static const int i = sizeof((B*)(D*)0);
763 the D*-to-B* conversion is a reinterpret_cast, not a
765 && COMPLETE_TYPE_P (TREE_TYPE (from)))
768 cp_build_qualified_type (TREE_TYPE (to),
769 cp_type_quals (TREE_TYPE (from)));
770 from = build_pointer_type (from);
771 conv = build_conv (ck_ptr, from, conv);
775 if (tcode == POINTER_TYPE)
777 to_pointee = TREE_TYPE (to);
778 from_pointee = TREE_TYPE (from);
782 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
783 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
786 if (same_type_p (from, to))
788 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
789 /* In a C-style cast, we ignore CV-qualification because we
790 are allowed to perform a static_cast followed by a
792 conv = build_conv (ck_qual, to, conv);
793 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
794 conv = build_conv (ck_qual, to, conv);
795 else if (expr && string_conv_p (to, expr, 0))
796 /* converting from string constant to char *. */
797 conv = build_conv (ck_qual, to, conv);
798 else if (ptr_reasonably_similar (to_pointee, from_pointee))
800 conv = build_conv (ck_ptr, to, conv);
808 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
810 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
811 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
812 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
813 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
815 if (!DERIVED_FROM_P (fbase, tbase)
816 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
817 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
818 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
819 || cp_type_quals (fbase) != cp_type_quals (tbase))
822 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
823 from = build_method_type_directly (from,
825 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
826 from = build_ptrmemfunc_type (build_pointer_type (from));
827 conv = build_conv (ck_pmem, from, conv);
830 else if (tcode == BOOLEAN_TYPE)
834 An rvalue of arithmetic, enumeration, pointer, or pointer to
835 member type can be converted to an rvalue of type bool. */
836 if (ARITHMETIC_TYPE_P (from)
837 || fcode == ENUMERAL_TYPE
838 || fcode == POINTER_TYPE
839 || TYPE_PTR_TO_MEMBER_P (from))
841 conv = build_conv (ck_std, to, conv);
842 if (fcode == POINTER_TYPE
843 || TYPE_PTRMEM_P (from)
844 || (TYPE_PTRMEMFUNC_P (from)
845 && conv->rank < cr_pbool))
846 conv->rank = cr_pbool;
852 /* We don't check for ENUMERAL_TYPE here because there are no standard
853 conversions to enum type. */
854 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
855 || tcode == REAL_TYPE)
857 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
859 conv = build_conv (ck_std, to, conv);
861 /* Give this a better rank if it's a promotion. */
862 if (same_type_p (to, type_promotes_to (from))
863 && conv->u.next->rank <= cr_promotion)
864 conv->rank = cr_promotion;
866 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
867 && vector_types_convertible_p (from, to, false))
868 return build_conv (ck_std, to, conv);
869 else if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE)
870 && IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
871 && is_properly_derived_from (from, to))
873 if (conv->kind == ck_rvalue)
875 conv = build_conv (ck_base, to, conv);
876 /* The derived-to-base conversion indicates the initialization
877 of a parameter with base type from an object of a derived
878 type. A temporary object is created to hold the result of
880 conv->need_temporary_p = true;
888 /* Returns nonzero if T1 is reference-related to T2. */
891 reference_related_p (tree t1, tree t2)
893 t1 = TYPE_MAIN_VARIANT (t1);
894 t2 = TYPE_MAIN_VARIANT (t2);
898 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
899 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
901 return (same_type_p (t1, t2)
902 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
903 && DERIVED_FROM_P (t1, t2)));
906 /* Returns nonzero if T1 is reference-compatible with T2. */
909 reference_compatible_p (tree t1, tree t2)
913 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
914 reference-related to T2 and cv1 is the same cv-qualification as,
915 or greater cv-qualification than, cv2. */
916 return (reference_related_p (t1, t2)
917 && at_least_as_qualified_p (t1, t2));
920 /* Determine whether or not the EXPR (of class type S) can be
921 converted to T as in [over.match.ref]. */
924 convert_class_to_reference (tree reference_type, tree s, tree expr)
930 struct z_candidate *candidates;
931 struct z_candidate *cand;
934 conversions = lookup_conversions (s);
940 Assuming that "cv1 T" is the underlying type of the reference
941 being initialized, and "cv S" is the type of the initializer
942 expression, with S a class type, the candidate functions are
945 --The conversion functions of S and its base classes are
946 considered. Those that are not hidden within S and yield type
947 "reference to cv2 T2", where "cv1 T" is reference-compatible
948 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
950 The argument list has one argument, which is the initializer
955 /* Conceptually, we should take the address of EXPR and put it in
956 the argument list. Unfortunately, however, that can result in
957 error messages, which we should not issue now because we are just
958 trying to find a conversion operator. Therefore, we use NULL,
959 cast to the appropriate type. */
960 arglist = build_int_cst (build_pointer_type (s), 0);
961 arglist = build_tree_list (NULL_TREE, arglist);
963 t = TREE_TYPE (reference_type);
967 tree fns = TREE_VALUE (conversions);
969 for (; fns; fns = OVL_NEXT (fns))
971 tree f = OVL_CURRENT (fns);
972 tree t2 = TREE_TYPE (TREE_TYPE (f));
976 /* If this is a template function, try to get an exact
978 if (TREE_CODE (f) == TEMPLATE_DECL)
980 cand = add_template_candidate (&candidates,
986 TREE_PURPOSE (conversions),
992 /* Now, see if the conversion function really returns
993 an lvalue of the appropriate type. From the
994 point of view of unification, simply returning an
995 rvalue of the right type is good enough. */
997 t2 = TREE_TYPE (TREE_TYPE (f));
998 if (TREE_CODE (t2) != REFERENCE_TYPE
999 || !reference_compatible_p (t, TREE_TYPE (t2)))
1001 candidates = candidates->next;
1006 else if (TREE_CODE (t2) == REFERENCE_TYPE
1007 && reference_compatible_p (t, TREE_TYPE (t2)))
1008 cand = add_function_candidate (&candidates, f, s, arglist,
1010 TREE_PURPOSE (conversions),
1015 conversion *identity_conv;
1016 /* Build a standard conversion sequence indicating the
1017 binding from the reference type returned by the
1018 function to the desired REFERENCE_TYPE. */
1020 = build_identity_conv (TREE_TYPE (TREE_TYPE
1021 (TREE_TYPE (cand->fn))),
1024 = (direct_reference_binding
1025 (reference_type, identity_conv));
1026 cand->second_conv->rvaluedness_matches_p
1027 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1028 == TYPE_REF_IS_RVALUE (reference_type);
1029 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1032 conversions = TREE_CHAIN (conversions);
1035 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1036 /* If none of the conversion functions worked out, let our caller
1041 cand = tourney (candidates);
1045 /* Now that we know that this is the function we're going to use fix
1046 the dummy first argument. */
1047 cand->args = tree_cons (NULL_TREE,
1049 TREE_CHAIN (cand->args));
1051 /* Build a user-defined conversion sequence representing the
1053 conv = build_conv (ck_user,
1054 TREE_TYPE (TREE_TYPE (cand->fn)),
1055 build_identity_conv (TREE_TYPE (expr), expr));
1058 /* Merge it with the standard conversion sequence from the
1059 conversion function's return type to the desired type. */
1060 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1062 if (cand->viable == -1)
1065 return cand->second_conv;
1068 /* A reference of the indicated TYPE is being bound directly to the
1069 expression represented by the implicit conversion sequence CONV.
1070 Return a conversion sequence for this binding. */
1073 direct_reference_binding (tree type, conversion *conv)
1077 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1078 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1080 t = TREE_TYPE (type);
1084 When a parameter of reference type binds directly
1085 (_dcl.init.ref_) to an argument expression, the implicit
1086 conversion sequence is the identity conversion, unless the
1087 argument expression has a type that is a derived class of the
1088 parameter type, in which case the implicit conversion sequence is
1089 a derived-to-base Conversion.
1091 If the parameter binds directly to the result of applying a
1092 conversion function to the argument expression, the implicit
1093 conversion sequence is a user-defined conversion sequence
1094 (_over.ics.user_), with the second standard conversion sequence
1095 either an identity conversion or, if the conversion function
1096 returns an entity of a type that is a derived class of the
1097 parameter type, a derived-to-base conversion. */
1098 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1100 /* Represent the derived-to-base conversion. */
1101 conv = build_conv (ck_base, t, conv);
1102 /* We will actually be binding to the base-class subobject in
1103 the derived class, so we mark this conversion appropriately.
1104 That way, convert_like knows not to generate a temporary. */
1105 conv->need_temporary_p = false;
1107 return build_conv (ck_ref_bind, type, conv);
1110 /* Returns the conversion path from type FROM to reference type TO for
1111 purposes of reference binding. For lvalue binding, either pass a
1112 reference type to FROM or an lvalue expression to EXPR. If the
1113 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1114 the conversion returned. If C_CAST_P is true, this
1115 conversion is coming from a C-style cast. */
1118 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1120 conversion *conv = NULL;
1121 tree to = TREE_TYPE (rto);
1125 cp_lvalue_kind lvalue_p = clk_none;
1127 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1129 expr = instantiate_type (to, expr, tf_none);
1130 if (expr == error_mark_node)
1132 from = TREE_TYPE (expr);
1135 if (TREE_CODE (from) == REFERENCE_TYPE)
1137 /* Anything with reference type is an lvalue. */
1138 lvalue_p = clk_ordinary;
1139 from = TREE_TYPE (from);
1142 lvalue_p = real_lvalue_p (expr);
1144 /* Figure out whether or not the types are reference-related and
1145 reference compatible. We have do do this after stripping
1146 references from FROM. */
1147 related_p = reference_related_p (to, from);
1148 /* If this is a C cast, first convert to an appropriately qualified
1149 type, so that we can later do a const_cast to the desired type. */
1150 if (related_p && c_cast_p
1151 && !at_least_as_qualified_p (to, from))
1152 to = build_qualified_type (to, cp_type_quals (from));
1153 compatible_p = reference_compatible_p (to, from);
1155 /* Directly bind reference when target expression's type is compatible with
1156 the reference and expression is an lvalue. In C++0x, the wording in
1157 [8.5.3/5 dcl.init.ref] is changed to also allow direct bindings for const
1158 and rvalue references to rvalues of compatible class type, as part of
1162 || ((cxx_dialect != cxx98)
1163 && (CP_TYPE_CONST_NON_VOLATILE_P(to) || TYPE_REF_IS_RVALUE (rto))
1164 && CLASS_TYPE_P (from))))
1168 If the initializer expression
1170 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1171 is reference-compatible with "cv2 T2,"
1173 the reference is bound directly to the initializer expression
1175 conv = build_identity_conv (from, expr);
1176 conv = direct_reference_binding (rto, conv);
1178 if (flags & LOOKUP_PREFER_RVALUE)
1179 /* The top-level caller requested that we pretend that the lvalue
1180 be treated as an rvalue. */
1181 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1183 conv->rvaluedness_matches_p
1184 = (TYPE_REF_IS_RVALUE (rto) == !lvalue_p);
1186 if ((lvalue_p & clk_bitfield) != 0
1187 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1188 /* For the purposes of overload resolution, we ignore the fact
1189 this expression is a bitfield or packed field. (In particular,
1190 [over.ics.ref] says specifically that a function with a
1191 non-const reference parameter is viable even if the
1192 argument is a bitfield.)
1194 However, when we actually call the function we must create
1195 a temporary to which to bind the reference. If the
1196 reference is volatile, or isn't const, then we cannot make
1197 a temporary, so we just issue an error when the conversion
1199 conv->need_temporary_p = true;
1203 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1207 If the initializer expression
1209 -- has a class type (i.e., T2 is a class type) can be
1210 implicitly converted to an lvalue of type "cv3 T3," where
1211 "cv1 T1" is reference-compatible with "cv3 T3". (this
1212 conversion is selected by enumerating the applicable
1213 conversion functions (_over.match.ref_) and choosing the
1214 best one through overload resolution. (_over.match_).
1216 the reference is bound to the lvalue result of the conversion
1217 in the second case. */
1218 conv = convert_class_to_reference (rto, from, expr);
1223 /* From this point on, we conceptually need temporaries, even if we
1224 elide them. Only the cases above are "direct bindings". */
1225 if (flags & LOOKUP_NO_TEMP_BIND)
1230 When a parameter of reference type is not bound directly to an
1231 argument expression, the conversion sequence is the one required
1232 to convert the argument expression to the underlying type of the
1233 reference according to _over.best.ics_. Conceptually, this
1234 conversion sequence corresponds to copy-initializing a temporary
1235 of the underlying type with the argument expression. Any
1236 difference in top-level cv-qualification is subsumed by the
1237 initialization itself and does not constitute a conversion. */
1241 Otherwise, the reference shall be to a non-volatile const type.
1243 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1244 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1249 If the initializer expression is an rvalue, with T2 a class type,
1250 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1251 is bound in one of the following ways:
1253 -- The reference is bound to the object represented by the rvalue
1254 or to a sub-object within that object.
1258 We use the first alternative. The implicit conversion sequence
1259 is supposed to be same as we would obtain by generating a
1260 temporary. Fortunately, if the types are reference compatible,
1261 then this is either an identity conversion or the derived-to-base
1262 conversion, just as for direct binding. */
1263 if (CLASS_TYPE_P (from) && compatible_p)
1265 conv = build_identity_conv (from, expr);
1266 conv = direct_reference_binding (rto, conv);
1267 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1268 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1269 conv->u.next->check_copy_constructor_p = true;
1275 Otherwise, a temporary of type "cv1 T1" is created and
1276 initialized from the initializer expression using the rules for a
1277 non-reference copy initialization. If T1 is reference-related to
1278 T2, cv1 must be the same cv-qualification as, or greater
1279 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1280 if (related_p && !at_least_as_qualified_p (to, from))
1283 conv = implicit_conversion (to, from, expr, c_cast_p,
1288 conv = build_conv (ck_ref_bind, rto, conv);
1289 /* This reference binding, unlike those above, requires the
1290 creation of a temporary. */
1291 conv->need_temporary_p = true;
1292 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1297 /* Returns the implicit conversion sequence (see [over.ics]) from type
1298 FROM to type TO. The optional expression EXPR may affect the
1299 conversion. FLAGS are the usual overloading flags. Only
1300 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1301 conversion is coming from a C-style cast. */
1304 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1309 if (from == error_mark_node || to == error_mark_node
1310 || expr == error_mark_node)
1313 if (TREE_CODE (to) == REFERENCE_TYPE)
1314 conv = reference_binding (to, from, expr, c_cast_p, flags);
1316 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1321 if (expr != NULL_TREE
1322 && (IS_AGGR_TYPE (from)
1323 || IS_AGGR_TYPE (to))
1324 && (flags & LOOKUP_NO_CONVERSION) == 0)
1326 struct z_candidate *cand;
1328 cand = build_user_type_conversion_1
1329 (to, expr, LOOKUP_ONLYCONVERTING);
1331 conv = cand->second_conv;
1333 /* We used to try to bind a reference to a temporary here, but that
1334 is now handled after the recursive call to this function at the end
1335 of reference_binding. */
1342 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1345 static struct z_candidate *
1346 add_candidate (struct z_candidate **candidates,
1348 size_t num_convs, conversion **convs,
1349 tree access_path, tree conversion_path,
1352 struct z_candidate *cand = (struct z_candidate *)
1353 conversion_obstack_alloc (sizeof (struct z_candidate));
1357 cand->convs = convs;
1358 cand->num_convs = num_convs;
1359 cand->access_path = access_path;
1360 cand->conversion_path = conversion_path;
1361 cand->viable = viable;
1362 cand->next = *candidates;
1368 /* Create an overload candidate for the function or method FN called with
1369 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1370 to implicit_conversion.
1372 CTYPE, if non-NULL, is the type we want to pretend this function
1373 comes from for purposes of overload resolution. */
1375 static struct z_candidate *
1376 add_function_candidate (struct z_candidate **candidates,
1377 tree fn, tree ctype, tree arglist,
1378 tree access_path, tree conversion_path,
1381 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1384 tree parmnode, argnode;
1388 /* At this point we should not see any functions which haven't been
1389 explicitly declared, except for friend functions which will have
1390 been found using argument dependent lookup. */
1391 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1393 /* The `this', `in_chrg' and VTT arguments to constructors are not
1394 considered in overload resolution. */
1395 if (DECL_CONSTRUCTOR_P (fn))
1397 parmlist = skip_artificial_parms_for (fn, parmlist);
1398 orig_arglist = arglist;
1399 arglist = skip_artificial_parms_for (fn, arglist);
1402 orig_arglist = arglist;
1404 len = list_length (arglist);
1405 convs = alloc_conversions (len);
1407 /* 13.3.2 - Viable functions [over.match.viable]
1408 First, to be a viable function, a candidate function shall have enough
1409 parameters to agree in number with the arguments in the list.
1411 We need to check this first; otherwise, checking the ICSes might cause
1412 us to produce an ill-formed template instantiation. */
1414 parmnode = parmlist;
1415 for (i = 0; i < len; ++i)
1417 if (parmnode == NULL_TREE || parmnode == void_list_node)
1419 parmnode = TREE_CHAIN (parmnode);
1422 if (i < len && parmnode)
1425 /* Make sure there are default args for the rest of the parms. */
1426 else if (!sufficient_parms_p (parmnode))
1432 /* Second, for F to be a viable function, there shall exist for each
1433 argument an implicit conversion sequence that converts that argument
1434 to the corresponding parameter of F. */
1436 parmnode = parmlist;
1439 for (i = 0; i < len; ++i)
1441 tree arg = TREE_VALUE (argnode);
1442 tree argtype = lvalue_type (arg);
1446 if (parmnode == void_list_node)
1449 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1450 && ! DECL_CONSTRUCTOR_P (fn));
1454 tree parmtype = TREE_VALUE (parmnode);
1456 /* The type of the implicit object parameter ('this') for
1457 overload resolution is not always the same as for the
1458 function itself; conversion functions are considered to
1459 be members of the class being converted, and functions
1460 introduced by a using-declaration are considered to be
1461 members of the class that uses them.
1463 Since build_over_call ignores the ICS for the `this'
1464 parameter, we can just change the parm type. */
1465 if (ctype && is_this)
1468 = build_qualified_type (ctype,
1469 TYPE_QUALS (TREE_TYPE (parmtype)));
1470 parmtype = build_pointer_type (parmtype);
1473 t = implicit_conversion (parmtype, argtype, arg,
1474 /*c_cast_p=*/false, flags);
1478 t = build_identity_conv (argtype, arg);
1479 t->ellipsis_p = true;
1496 parmnode = TREE_CHAIN (parmnode);
1497 argnode = TREE_CHAIN (argnode);
1501 return add_candidate (candidates, fn, orig_arglist, len, convs,
1502 access_path, conversion_path, viable);
1505 /* Create an overload candidate for the conversion function FN which will
1506 be invoked for expression OBJ, producing a pointer-to-function which
1507 will in turn be called with the argument list ARGLIST, and add it to
1508 CANDIDATES. FLAGS is passed on to implicit_conversion.
1510 Actually, we don't really care about FN; we care about the type it
1511 converts to. There may be multiple conversion functions that will
1512 convert to that type, and we rely on build_user_type_conversion_1 to
1513 choose the best one; so when we create our candidate, we record the type
1514 instead of the function. */
1516 static struct z_candidate *
1517 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1518 tree arglist, tree access_path, tree conversion_path)
1520 tree totype = TREE_TYPE (TREE_TYPE (fn));
1521 int i, len, viable, flags;
1522 tree parmlist, parmnode, argnode;
1525 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1526 parmlist = TREE_TYPE (parmlist);
1527 parmlist = TYPE_ARG_TYPES (parmlist);
1529 len = list_length (arglist) + 1;
1530 convs = alloc_conversions (len);
1531 parmnode = parmlist;
1534 flags = LOOKUP_NORMAL;
1536 /* Don't bother looking up the same type twice. */
1537 if (*candidates && (*candidates)->fn == totype)
1540 for (i = 0; i < len; ++i)
1542 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1543 tree argtype = lvalue_type (arg);
1547 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1549 else if (parmnode == void_list_node)
1552 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1553 /*c_cast_p=*/false, flags);
1556 t = build_identity_conv (argtype, arg);
1557 t->ellipsis_p = true;
1571 parmnode = TREE_CHAIN (parmnode);
1572 argnode = TREE_CHAIN (argnode);
1578 if (!sufficient_parms_p (parmnode))
1581 return add_candidate (candidates, totype, arglist, len, convs,
1582 access_path, conversion_path, viable);
1586 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1587 tree type1, tree type2, tree *args, tree *argtypes,
1599 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1600 convs = alloc_conversions (num_convs);
1602 for (i = 0; i < 2; ++i)
1607 t = implicit_conversion (types[i], argtypes[i], args[i],
1608 /*c_cast_p=*/false, flags);
1612 /* We need something for printing the candidate. */
1613 t = build_identity_conv (types[i], NULL_TREE);
1620 /* For COND_EXPR we rearranged the arguments; undo that now. */
1623 convs[2] = convs[1];
1624 convs[1] = convs[0];
1625 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1626 /*c_cast_p=*/false, flags);
1633 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1635 /*access_path=*/NULL_TREE,
1636 /*conversion_path=*/NULL_TREE,
1641 is_complete (tree t)
1643 return COMPLETE_TYPE_P (complete_type (t));
1646 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1649 promoted_arithmetic_type_p (tree type)
1653 In this section, the term promoted integral type is used to refer
1654 to those integral types which are preserved by integral promotion
1655 (including e.g. int and long but excluding e.g. char).
1656 Similarly, the term promoted arithmetic type refers to promoted
1657 integral types plus floating types. */
1658 return ((INTEGRAL_TYPE_P (type)
1659 && same_type_p (type_promotes_to (type), type))
1660 || TREE_CODE (type) == REAL_TYPE);
1663 /* Create any builtin operator overload candidates for the operator in
1664 question given the converted operand types TYPE1 and TYPE2. The other
1665 args are passed through from add_builtin_candidates to
1666 build_builtin_candidate.
1668 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1669 If CODE is requires candidates operands of the same type of the kind
1670 of which TYPE1 and TYPE2 are, we add both candidates
1671 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1674 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1675 enum tree_code code2, tree fnname, tree type1,
1676 tree type2, tree *args, tree *argtypes, int flags)
1680 case POSTINCREMENT_EXPR:
1681 case POSTDECREMENT_EXPR:
1682 args[1] = integer_zero_node;
1683 type2 = integer_type_node;
1692 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1693 and VQ is either volatile or empty, there exist candidate operator
1694 functions of the form
1695 VQ T& operator++(VQ T&);
1696 T operator++(VQ T&, int);
1697 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1698 type other than bool, and VQ is either volatile or empty, there exist
1699 candidate operator functions of the form
1700 VQ T& operator--(VQ T&);
1701 T operator--(VQ T&, int);
1702 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1703 complete object type, and VQ is either volatile or empty, there exist
1704 candidate operator functions of the form
1705 T*VQ& operator++(T*VQ&);
1706 T*VQ& operator--(T*VQ&);
1707 T* operator++(T*VQ&, int);
1708 T* operator--(T*VQ&, int); */
1710 case POSTDECREMENT_EXPR:
1711 case PREDECREMENT_EXPR:
1712 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1714 case POSTINCREMENT_EXPR:
1715 case PREINCREMENT_EXPR:
1716 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1718 type1 = build_reference_type (type1);
1723 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1724 exist candidate operator functions of the form
1728 8 For every function type T, there exist candidate operator functions of
1730 T& operator*(T*); */
1733 if (TREE_CODE (type1) == POINTER_TYPE
1734 && (TYPE_PTROB_P (type1)
1735 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1739 /* 9 For every type T, there exist candidate operator functions of the form
1742 10For every promoted arithmetic type T, there exist candidate operator
1743 functions of the form
1747 case UNARY_PLUS_EXPR: /* unary + */
1748 if (TREE_CODE (type1) == POINTER_TYPE)
1751 if (ARITHMETIC_TYPE_P (type1))
1755 /* 11For every promoted integral type T, there exist candidate operator
1756 functions of the form
1760 if (INTEGRAL_TYPE_P (type1))
1764 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1765 is the same type as C2 or is a derived class of C2, T is a complete
1766 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1767 there exist candidate operator functions of the form
1768 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1769 where CV12 is the union of CV1 and CV2. */
1772 if (TREE_CODE (type1) == POINTER_TYPE
1773 && TYPE_PTR_TO_MEMBER_P (type2))
1775 tree c1 = TREE_TYPE (type1);
1776 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1778 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1779 && (TYPE_PTRMEMFUNC_P (type2)
1780 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1785 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1786 didate operator functions of the form
1791 bool operator<(L, R);
1792 bool operator>(L, R);
1793 bool operator<=(L, R);
1794 bool operator>=(L, R);
1795 bool operator==(L, R);
1796 bool operator!=(L, R);
1797 where LR is the result of the usual arithmetic conversions between
1800 14For every pair of types T and I, where T is a cv-qualified or cv-
1801 unqualified complete object type and I is a promoted integral type,
1802 there exist candidate operator functions of the form
1803 T* operator+(T*, I);
1804 T& operator[](T*, I);
1805 T* operator-(T*, I);
1806 T* operator+(I, T*);
1807 T& operator[](I, T*);
1809 15For every T, where T is a pointer to complete object type, there exist
1810 candidate operator functions of the form112)
1811 ptrdiff_t operator-(T, T);
1813 16For every pointer or enumeration type T, there exist candidate operator
1814 functions of the form
1815 bool operator<(T, T);
1816 bool operator>(T, T);
1817 bool operator<=(T, T);
1818 bool operator>=(T, T);
1819 bool operator==(T, T);
1820 bool operator!=(T, T);
1822 17For every pointer to member type T, there exist candidate operator
1823 functions of the form
1824 bool operator==(T, T);
1825 bool operator!=(T, T); */
1828 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1830 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1832 type2 = ptrdiff_type_node;
1836 case TRUNC_DIV_EXPR:
1837 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1843 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1844 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1846 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1851 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1863 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1865 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1867 if (TREE_CODE (type1) == ENUMERAL_TYPE
1868 && TREE_CODE (type2) == ENUMERAL_TYPE)
1870 if (TYPE_PTR_P (type1)
1871 && null_ptr_cst_p (args[1])
1872 && !uses_template_parms (type1))
1877 if (null_ptr_cst_p (args[0])
1878 && TYPE_PTR_P (type2)
1879 && !uses_template_parms (type2))
1887 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1890 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1892 type1 = ptrdiff_type_node;
1895 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1897 type2 = ptrdiff_type_node;
1902 /* 18For every pair of promoted integral types L and R, there exist candi-
1903 date operator functions of the form
1910 where LR is the result of the usual arithmetic conversions between
1913 case TRUNC_MOD_EXPR:
1919 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1923 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1924 type, VQ is either volatile or empty, and R is a promoted arithmetic
1925 type, there exist candidate operator functions of the form
1926 VQ L& operator=(VQ L&, R);
1927 VQ L& operator*=(VQ L&, R);
1928 VQ L& operator/=(VQ L&, R);
1929 VQ L& operator+=(VQ L&, R);
1930 VQ L& operator-=(VQ L&, R);
1932 20For every pair T, VQ), where T is any type and VQ is either volatile
1933 or empty, there exist candidate operator functions of the form
1934 T*VQ& operator=(T*VQ&, T*);
1936 21For every pair T, VQ), where T is a pointer to member type and VQ is
1937 either volatile or empty, there exist candidate operator functions of
1939 VQ T& operator=(VQ T&, T);
1941 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1942 unqualified complete object type, VQ is either volatile or empty, and
1943 I is a promoted integral type, there exist candidate operator func-
1945 T*VQ& operator+=(T*VQ&, I);
1946 T*VQ& operator-=(T*VQ&, I);
1948 23For every triple L, VQ, R), where L is an integral or enumeration
1949 type, VQ is either volatile or empty, and R is a promoted integral
1950 type, there exist candidate operator functions of the form
1952 VQ L& operator%=(VQ L&, R);
1953 VQ L& operator<<=(VQ L&, R);
1954 VQ L& operator>>=(VQ L&, R);
1955 VQ L& operator&=(VQ L&, R);
1956 VQ L& operator^=(VQ L&, R);
1957 VQ L& operator|=(VQ L&, R); */
1964 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1966 type2 = ptrdiff_type_node;
1970 case TRUNC_DIV_EXPR:
1971 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1975 case TRUNC_MOD_EXPR:
1981 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1986 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1988 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1989 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1990 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1991 || ((TYPE_PTRMEMFUNC_P (type1)
1992 || TREE_CODE (type1) == POINTER_TYPE)
1993 && null_ptr_cst_p (args[1])))
2003 type1 = build_reference_type (type1);
2009 For every pair of promoted arithmetic types L and R, there
2010 exist candidate operator functions of the form
2012 LR operator?(bool, L, R);
2014 where LR is the result of the usual arithmetic conversions
2015 between types L and R.
2017 For every type T, where T is a pointer or pointer-to-member
2018 type, there exist candidate operator functions of the form T
2019 operator?(bool, T, T); */
2021 if (promoted_arithmetic_type_p (type1)
2022 && promoted_arithmetic_type_p (type2))
2026 /* Otherwise, the types should be pointers. */
2027 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2028 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2031 /* We don't check that the two types are the same; the logic
2032 below will actually create two candidates; one in which both
2033 parameter types are TYPE1, and one in which both parameter
2041 /* If we're dealing with two pointer types or two enumeral types,
2042 we need candidates for both of them. */
2043 if (type2 && !same_type_p (type1, type2)
2044 && TREE_CODE (type1) == TREE_CODE (type2)
2045 && (TREE_CODE (type1) == REFERENCE_TYPE
2046 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2047 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2048 || TYPE_PTRMEMFUNC_P (type1)
2049 || IS_AGGR_TYPE (type1)
2050 || TREE_CODE (type1) == ENUMERAL_TYPE))
2052 build_builtin_candidate
2053 (candidates, fnname, type1, type1, args, argtypes, flags);
2054 build_builtin_candidate
2055 (candidates, fnname, type2, type2, args, argtypes, flags);
2059 build_builtin_candidate
2060 (candidates, fnname, type1, type2, args, argtypes, flags);
2064 type_decays_to (tree type)
2066 if (TREE_CODE (type) == ARRAY_TYPE)
2067 return build_pointer_type (TREE_TYPE (type));
2068 if (TREE_CODE (type) == FUNCTION_TYPE)
2069 return build_pointer_type (type);
2073 /* There are three conditions of builtin candidates:
2075 1) bool-taking candidates. These are the same regardless of the input.
2076 2) pointer-pair taking candidates. These are generated for each type
2077 one of the input types converts to.
2078 3) arithmetic candidates. According to the standard, we should generate
2079 all of these, but I'm trying not to...
2081 Here we generate a superset of the possible candidates for this particular
2082 case. That is a subset of the full set the standard defines, plus some
2083 other cases which the standard disallows. add_builtin_candidate will
2084 filter out the invalid set. */
2087 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2088 enum tree_code code2, tree fnname, tree *args,
2093 tree type, argtypes[3];
2094 /* TYPES[i] is the set of possible builtin-operator parameter types
2095 we will consider for the Ith argument. These are represented as
2096 a TREE_LIST; the TREE_VALUE of each node is the potential
2100 for (i = 0; i < 3; ++i)
2103 argtypes[i] = lvalue_type (args[i]);
2105 argtypes[i] = NULL_TREE;
2110 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2111 and VQ is either volatile or empty, there exist candidate operator
2112 functions of the form
2113 VQ T& operator++(VQ T&); */
2115 case POSTINCREMENT_EXPR:
2116 case PREINCREMENT_EXPR:
2117 case POSTDECREMENT_EXPR:
2118 case PREDECREMENT_EXPR:
2123 /* 24There also exist candidate operator functions of the form
2124 bool operator!(bool);
2125 bool operator&&(bool, bool);
2126 bool operator||(bool, bool); */
2128 case TRUTH_NOT_EXPR:
2129 build_builtin_candidate
2130 (candidates, fnname, boolean_type_node,
2131 NULL_TREE, args, argtypes, flags);
2134 case TRUTH_ORIF_EXPR:
2135 case TRUTH_ANDIF_EXPR:
2136 build_builtin_candidate
2137 (candidates, fnname, boolean_type_node,
2138 boolean_type_node, args, argtypes, flags);
2160 types[0] = types[1] = NULL_TREE;
2162 for (i = 0; i < 2; ++i)
2166 else if (IS_AGGR_TYPE (argtypes[i]))
2170 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2173 convs = lookup_conversions (argtypes[i]);
2175 if (code == COND_EXPR)
2177 if (real_lvalue_p (args[i]))
2178 types[i] = tree_cons
2179 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2181 types[i] = tree_cons
2182 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2188 for (; convs; convs = TREE_CHAIN (convs))
2190 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2193 && (TREE_CODE (type) != REFERENCE_TYPE
2194 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2197 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2198 types[i] = tree_cons (NULL_TREE, type, types[i]);
2200 type = non_reference (type);
2201 if (i != 0 || ! ref1)
2203 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2204 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2205 types[i] = tree_cons (NULL_TREE, type, types[i]);
2206 if (INTEGRAL_TYPE_P (type))
2207 type = type_promotes_to (type);
2210 if (! value_member (type, types[i]))
2211 types[i] = tree_cons (NULL_TREE, type, types[i]);
2216 if (code == COND_EXPR && real_lvalue_p (args[i]))
2217 types[i] = tree_cons
2218 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2219 type = non_reference (argtypes[i]);
2220 if (i != 0 || ! ref1)
2222 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2223 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2224 types[i] = tree_cons (NULL_TREE, type, types[i]);
2225 if (INTEGRAL_TYPE_P (type))
2226 type = type_promotes_to (type);
2228 types[i] = tree_cons (NULL_TREE, type, types[i]);
2232 /* Run through the possible parameter types of both arguments,
2233 creating candidates with those parameter types. */
2234 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2237 for (type = types[1]; type; type = TREE_CHAIN (type))
2238 add_builtin_candidate
2239 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2240 TREE_VALUE (type), args, argtypes, flags);
2242 add_builtin_candidate
2243 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2244 NULL_TREE, args, argtypes, flags);
2249 /* If TMPL can be successfully instantiated as indicated by
2250 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2252 TMPL is the template. EXPLICIT_TARGS are any explicit template
2253 arguments. ARGLIST is the arguments provided at the call-site.
2254 The RETURN_TYPE is the desired type for conversion operators. If
2255 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2256 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2257 add_conv_candidate. */
2259 static struct z_candidate*
2260 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2261 tree ctype, tree explicit_targs, tree arglist,
2262 tree return_type, tree access_path,
2263 tree conversion_path, int flags, tree obj,
2264 unification_kind_t strict)
2266 int ntparms = DECL_NTPARMS (tmpl);
2267 tree targs = make_tree_vec (ntparms);
2268 tree args_without_in_chrg = arglist;
2269 struct z_candidate *cand;
2273 /* We don't do deduction on the in-charge parameter, the VTT
2274 parameter or 'this'. */
2275 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2276 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2278 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2279 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2280 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2281 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2283 i = fn_type_unification (tmpl, explicit_targs, targs,
2284 args_without_in_chrg,
2285 return_type, strict, flags);
2290 fn = instantiate_template (tmpl, targs, tf_none);
2291 if (fn == error_mark_node)
2296 A member function template is never instantiated to perform the
2297 copy of a class object to an object of its class type.
2299 It's a little unclear what this means; the standard explicitly
2300 does allow a template to be used to copy a class. For example,
2305 template <class T> A(const T&);
2308 void g () { A a (f ()); }
2310 the member template will be used to make the copy. The section
2311 quoted above appears in the paragraph that forbids constructors
2312 whose only parameter is (a possibly cv-qualified variant of) the
2313 class type, and a logical interpretation is that the intent was
2314 to forbid the instantiation of member templates which would then
2316 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2318 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2319 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2324 if (obj != NULL_TREE)
2325 /* Aha, this is a conversion function. */
2326 cand = add_conv_candidate (candidates, fn, obj, access_path,
2327 conversion_path, arglist);
2329 cand = add_function_candidate (candidates, fn, ctype,
2330 arglist, access_path,
2331 conversion_path, flags);
2332 if (DECL_TI_TEMPLATE (fn) != tmpl)
2333 /* This situation can occur if a member template of a template
2334 class is specialized. Then, instantiate_template might return
2335 an instantiation of the specialization, in which case the
2336 DECL_TI_TEMPLATE field will point at the original
2337 specialization. For example:
2339 template <class T> struct S { template <class U> void f(U);
2340 template <> void f(int) {}; };
2344 Here, TMPL will be template <class U> S<double>::f(U).
2345 And, instantiate template will give us the specialization
2346 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2347 for this will point at template <class T> template <> S<T>::f(int),
2348 so that we can find the definition. For the purposes of
2349 overload resolution, however, we want the original TMPL. */
2350 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2352 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2358 static struct z_candidate *
2359 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2360 tree explicit_targs, tree arglist, tree return_type,
2361 tree access_path, tree conversion_path, int flags,
2362 unification_kind_t strict)
2365 add_template_candidate_real (candidates, tmpl, ctype,
2366 explicit_targs, arglist, return_type,
2367 access_path, conversion_path,
2368 flags, NULL_TREE, strict);
2372 static struct z_candidate *
2373 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2374 tree obj, tree arglist, tree return_type,
2375 tree access_path, tree conversion_path)
2378 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2379 arglist, return_type, access_path,
2380 conversion_path, 0, obj, DEDUCE_CONV);
2383 /* The CANDS are the set of candidates that were considered for
2384 overload resolution. Return the set of viable candidates. If none
2385 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2386 is true if a candidate should be considered viable only if it is
2389 static struct z_candidate*
2390 splice_viable (struct z_candidate *cands,
2394 struct z_candidate *viable;
2395 struct z_candidate **last_viable;
2396 struct z_candidate **cand;
2399 last_viable = &viable;
2400 *any_viable_p = false;
2405 struct z_candidate *c = *cand;
2406 if (strict_p ? c->viable == 1 : c->viable)
2411 last_viable = &c->next;
2412 *any_viable_p = true;
2418 return viable ? viable : cands;
2422 any_strictly_viable (struct z_candidate *cands)
2424 for (; cands; cands = cands->next)
2425 if (cands->viable == 1)
2430 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2431 words, it is about to become the "this" pointer for a member
2432 function call. Take the address of the object. */
2435 build_this (tree obj)
2437 /* In a template, we are only concerned about the type of the
2438 expression, so we can take a shortcut. */
2439 if (processing_template_decl)
2440 return build_address (obj);
2442 return build_unary_op (ADDR_EXPR, obj, 0);
2445 /* Returns true iff functions are equivalent. Equivalent functions are
2446 not '==' only if one is a function-local extern function or if
2447 both are extern "C". */
2450 equal_functions (tree fn1, tree fn2)
2452 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2453 || DECL_EXTERN_C_FUNCTION_P (fn1))
2454 return decls_match (fn1, fn2);
2458 /* Print information about one overload candidate CANDIDATE. MSGSTR
2459 is the text to print before the candidate itself.
2461 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2462 to have been run through gettext by the caller. This wart makes
2463 life simpler in print_z_candidates and for the translators. */
2466 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2468 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2470 if (candidate->num_convs == 3)
2471 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2472 candidate->convs[0]->type,
2473 candidate->convs[1]->type,
2474 candidate->convs[2]->type);
2475 else if (candidate->num_convs == 2)
2476 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2477 candidate->convs[0]->type,
2478 candidate->convs[1]->type);
2480 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2481 candidate->convs[0]->type);
2483 else if (TYPE_P (candidate->fn))
2484 inform ("%s %T <conversion>", msgstr, candidate->fn);
2485 else if (candidate->viable == -1)
2486 inform ("%s %+#D <near match>", msgstr, candidate->fn);
2488 inform ("%s %+#D", msgstr, candidate->fn);
2492 print_z_candidates (struct z_candidate *candidates)
2495 struct z_candidate *cand1;
2496 struct z_candidate **cand2;
2498 /* There may be duplicates in the set of candidates. We put off
2499 checking this condition as long as possible, since we have no way
2500 to eliminate duplicates from a set of functions in less than n^2
2501 time. Now we are about to emit an error message, so it is more
2502 permissible to go slowly. */
2503 for (cand1 = candidates; cand1; cand1 = cand1->next)
2505 tree fn = cand1->fn;
2506 /* Skip builtin candidates and conversion functions. */
2507 if (TREE_CODE (fn) != FUNCTION_DECL)
2509 cand2 = &cand1->next;
2512 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2513 && equal_functions (fn, (*cand2)->fn))
2514 *cand2 = (*cand2)->next;
2516 cand2 = &(*cand2)->next;
2523 str = _("candidates are:");
2524 print_z_candidate (str, candidates);
2525 if (candidates->next)
2527 /* Indent successive candidates by the width of the translation
2528 of the above string. */
2529 size_t len = gcc_gettext_width (str) + 1;
2530 char *spaces = (char *) alloca (len);
2531 memset (spaces, ' ', len-1);
2532 spaces[len - 1] = '\0';
2534 candidates = candidates->next;
2537 print_z_candidate (spaces, candidates);
2538 candidates = candidates->next;
2544 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2545 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2546 the result of the conversion function to convert it to the final
2547 desired type. Merge the two sequences into a single sequence,
2548 and return the merged sequence. */
2551 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2555 gcc_assert (user_seq->kind == ck_user);
2557 /* Find the end of the second conversion sequence. */
2559 while ((*t)->kind != ck_identity)
2560 t = &((*t)->u.next);
2562 /* Replace the identity conversion with the user conversion
2566 /* The entire sequence is a user-conversion sequence. */
2567 std_seq->user_conv_p = true;
2572 /* Returns the best overload candidate to perform the requested
2573 conversion. This function is used for three the overloading situations
2574 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2575 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2576 per [dcl.init.ref], so we ignore temporary bindings. */
2578 static struct z_candidate *
2579 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2581 struct z_candidate *candidates, *cand;
2582 tree fromtype = TREE_TYPE (expr);
2583 tree ctors = NULL_TREE;
2584 tree conv_fns = NULL_TREE;
2585 conversion *conv = NULL;
2586 tree args = NULL_TREE;
2589 /* We represent conversion within a hierarchy using RVALUE_CONV and
2590 BASE_CONV, as specified by [over.best.ics]; these become plain
2591 constructor calls, as specified in [dcl.init]. */
2592 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2593 || !DERIVED_FROM_P (totype, fromtype));
2595 if (IS_AGGR_TYPE (totype))
2596 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2598 if (IS_AGGR_TYPE (fromtype))
2599 conv_fns = lookup_conversions (fromtype);
2602 flags |= LOOKUP_NO_CONVERSION;
2608 ctors = BASELINK_FUNCTIONS (ctors);
2610 t = build_int_cst (build_pointer_type (totype), 0);
2611 args = build_tree_list (NULL_TREE, expr);
2612 /* We should never try to call the abstract or base constructor
2614 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2615 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2616 args = tree_cons (NULL_TREE, t, args);
2618 for (; ctors; ctors = OVL_NEXT (ctors))
2620 tree ctor = OVL_CURRENT (ctors);
2621 if (DECL_NONCONVERTING_P (ctor))
2624 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2625 cand = add_template_candidate (&candidates, ctor, totype,
2626 NULL_TREE, args, NULL_TREE,
2627 TYPE_BINFO (totype),
2628 TYPE_BINFO (totype),
2632 cand = add_function_candidate (&candidates, ctor, totype,
2633 args, TYPE_BINFO (totype),
2634 TYPE_BINFO (totype),
2638 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2642 args = build_tree_list (NULL_TREE, build_this (expr));
2644 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2647 tree conversion_path = TREE_PURPOSE (conv_fns);
2648 int convflags = LOOKUP_NO_CONVERSION;
2650 /* If we are called to convert to a reference type, we are trying to
2651 find an lvalue binding, so don't even consider temporaries. If
2652 we don't find an lvalue binding, the caller will try again to
2653 look for a temporary binding. */
2654 if (TREE_CODE (totype) == REFERENCE_TYPE)
2655 convflags |= LOOKUP_NO_TEMP_BIND;
2657 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2659 tree fn = OVL_CURRENT (fns);
2661 /* [over.match.funcs] For conversion functions, the function
2662 is considered to be a member of the class of the implicit
2663 object argument for the purpose of defining the type of
2664 the implicit object parameter.
2666 So we pass fromtype as CTYPE to add_*_candidate. */
2668 if (TREE_CODE (fn) == TEMPLATE_DECL)
2669 cand = add_template_candidate (&candidates, fn, fromtype,
2672 TYPE_BINFO (fromtype),
2677 cand = add_function_candidate (&candidates, fn, fromtype,
2679 TYPE_BINFO (fromtype),
2686 = implicit_conversion (totype,
2687 TREE_TYPE (TREE_TYPE (cand->fn)),
2689 /*c_cast_p=*/false, convflags);
2691 cand->second_conv = ics;
2695 else if (candidates->viable == 1 && ics->bad_p)
2701 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2705 cand = tourney (candidates);
2708 if (flags & LOOKUP_COMPLAIN)
2710 error ("conversion from %qT to %qT is ambiguous",
2712 print_z_candidates (candidates);
2715 cand = candidates; /* any one will do */
2716 cand->second_conv = build_ambiguous_conv (totype, expr);
2717 cand->second_conv->user_conv_p = true;
2718 if (!any_strictly_viable (candidates))
2719 cand->second_conv->bad_p = true;
2720 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2721 ambiguous conversion is no worse than another user-defined
2727 /* Build the user conversion sequence. */
2730 (DECL_CONSTRUCTOR_P (cand->fn)
2731 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2732 build_identity_conv (TREE_TYPE (expr), expr));
2735 /* Combine it with the second conversion sequence. */
2736 cand->second_conv = merge_conversion_sequences (conv,
2739 if (cand->viable == -1)
2740 cand->second_conv->bad_p = true;
2746 build_user_type_conversion (tree totype, tree expr, int flags)
2748 struct z_candidate *cand
2749 = build_user_type_conversion_1 (totype, expr, flags);
2753 if (cand->second_conv->kind == ck_ambig)
2754 return error_mark_node;
2755 expr = convert_like (cand->second_conv, expr);
2756 return convert_from_reference (expr);
2761 /* Do any initial processing on the arguments to a function call. */
2764 resolve_args (tree args)
2767 for (t = args; t; t = TREE_CHAIN (t))
2769 tree arg = TREE_VALUE (t);
2771 if (error_operand_p (arg))
2772 return error_mark_node;
2773 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2775 error ("invalid use of void expression");
2776 return error_mark_node;
2778 else if (invalid_nonstatic_memfn_p (arg))
2779 return error_mark_node;
2784 /* Perform overload resolution on FN, which is called with the ARGS.
2786 Return the candidate function selected by overload resolution, or
2787 NULL if the event that overload resolution failed. In the case
2788 that overload resolution fails, *CANDIDATES will be the set of
2789 candidates considered, and ANY_VIABLE_P will be set to true or
2790 false to indicate whether or not any of the candidates were
2793 The ARGS should already have gone through RESOLVE_ARGS before this
2794 function is called. */
2796 static struct z_candidate *
2797 perform_overload_resolution (tree fn,
2799 struct z_candidate **candidates,
2802 struct z_candidate *cand;
2803 tree explicit_targs = NULL_TREE;
2804 int template_only = 0;
2807 *any_viable_p = true;
2809 /* Check FN and ARGS. */
2810 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2811 || TREE_CODE (fn) == TEMPLATE_DECL
2812 || TREE_CODE (fn) == OVERLOAD
2813 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2814 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2816 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2818 explicit_targs = TREE_OPERAND (fn, 1);
2819 fn = TREE_OPERAND (fn, 0);
2823 /* Add the various candidate functions. */
2824 add_candidates (fn, args, explicit_targs, template_only,
2825 /*conversion_path=*/NULL_TREE,
2826 /*access_path=*/NULL_TREE,
2830 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2834 cand = tourney (*candidates);
2838 /* Return an expression for a call to FN (a namespace-scope function,
2839 or a static member function) with the ARGS. */
2842 build_new_function_call (tree fn, tree args, bool koenig_p)
2844 struct z_candidate *candidates, *cand;
2849 args = resolve_args (args);
2850 if (args == error_mark_node)
2851 return error_mark_node;
2853 /* If this function was found without using argument dependent
2854 lookup, then we want to ignore any undeclared friend
2860 fn = remove_hidden_names (fn);
2863 error ("no matching function for call to %<%D(%A)%>",
2864 DECL_NAME (OVL_CURRENT (orig_fn)), args);
2865 return error_mark_node;
2869 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2870 p = conversion_obstack_alloc (0);
2872 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2876 if (!any_viable_p && candidates && ! candidates->next)
2877 return build_function_call (candidates->fn, args);
2878 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2879 fn = TREE_OPERAND (fn, 0);
2881 error ("no matching function for call to %<%D(%A)%>",
2882 DECL_NAME (OVL_CURRENT (fn)), args);
2884 error ("call of overloaded %<%D(%A)%> is ambiguous",
2885 DECL_NAME (OVL_CURRENT (fn)), args);
2887 print_z_candidates (candidates);
2888 result = error_mark_node;
2891 result = build_over_call (cand, LOOKUP_NORMAL);
2893 /* Free all the conversions we allocated. */
2894 obstack_free (&conversion_obstack, p);
2899 /* Build a call to a global operator new. FNNAME is the name of the
2900 operator (either "operator new" or "operator new[]") and ARGS are
2901 the arguments provided. *SIZE points to the total number of bytes
2902 required by the allocation, and is updated if that is changed here.
2903 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2904 function determines that no cookie should be used, after all,
2905 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2906 set, upon return, to the allocation function called. */
2909 build_operator_new_call (tree fnname, tree args,
2910 tree *size, tree *cookie_size,
2914 struct z_candidate *candidates;
2915 struct z_candidate *cand;
2920 args = tree_cons (NULL_TREE, *size, args);
2921 args = resolve_args (args);
2922 if (args == error_mark_node)
2929 If this lookup fails to find the name, or if the allocated type
2930 is not a class type, the allocation function's name is looked
2931 up in the global scope.
2933 we disregard block-scope declarations of "operator new". */
2934 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2936 /* Figure out what function is being called. */
2937 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2939 /* If no suitable function could be found, issue an error message
2944 error ("no matching function for call to %<%D(%A)%>",
2945 DECL_NAME (OVL_CURRENT (fns)), args);
2947 error ("call of overloaded %<%D(%A)%> is ambiguous",
2948 DECL_NAME (OVL_CURRENT (fns)), args);
2950 print_z_candidates (candidates);
2951 return error_mark_node;
2954 /* If a cookie is required, add some extra space. Whether
2955 or not a cookie is required cannot be determined until
2956 after we know which function was called. */
2959 bool use_cookie = true;
2960 if (!abi_version_at_least (2))
2962 tree placement = TREE_CHAIN (args);
2963 /* In G++ 3.2, the check was implemented incorrectly; it
2964 looked at the placement expression, rather than the
2965 type of the function. */
2966 if (placement && !TREE_CHAIN (placement)
2967 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2975 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2976 /* Skip the size_t parameter. */
2977 arg_types = TREE_CHAIN (arg_types);
2978 /* Check the remaining parameters (if any). */
2980 && TREE_CHAIN (arg_types) == void_list_node
2981 && same_type_p (TREE_VALUE (arg_types),
2985 /* If we need a cookie, adjust the number of bytes allocated. */
2988 /* Update the total size. */
2989 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2990 /* Update the argument list to reflect the adjusted size. */
2991 TREE_VALUE (args) = *size;
2994 *cookie_size = NULL_TREE;
2997 /* Tell our caller which function we decided to call. */
3001 /* Build the CALL_EXPR. */
3002 return build_over_call (cand, LOOKUP_NORMAL);
3006 build_object_call (tree obj, tree args)
3008 struct z_candidate *candidates = 0, *cand;
3009 tree fns, convs, mem_args = NULL_TREE;
3010 tree type = TREE_TYPE (obj);
3012 tree result = NULL_TREE;
3015 if (TYPE_PTRMEMFUNC_P (type))
3017 /* It's no good looking for an overloaded operator() on a
3018 pointer-to-member-function. */
3019 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3020 return error_mark_node;
3023 if (TYPE_BINFO (type))
3025 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3026 if (fns == error_mark_node)
3027 return error_mark_node;
3032 args = resolve_args (args);
3034 if (args == error_mark_node)
3035 return error_mark_node;
3037 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3038 p = conversion_obstack_alloc (0);
3042 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
3043 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
3045 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3047 tree fn = OVL_CURRENT (fns);
3048 if (TREE_CODE (fn) == TEMPLATE_DECL)
3049 add_template_candidate (&candidates, fn, base, NULL_TREE,
3050 mem_args, NULL_TREE,
3053 LOOKUP_NORMAL, DEDUCE_CALL);
3055 add_function_candidate
3056 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3057 TYPE_BINFO (type), LOOKUP_NORMAL);
3061 convs = lookup_conversions (type);
3063 for (; convs; convs = TREE_CHAIN (convs))
3065 tree fns = TREE_VALUE (convs);
3066 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3068 if ((TREE_CODE (totype) == POINTER_TYPE
3069 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3070 || (TREE_CODE (totype) == REFERENCE_TYPE
3071 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3072 || (TREE_CODE (totype) == REFERENCE_TYPE
3073 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3074 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3075 for (; fns; fns = OVL_NEXT (fns))
3077 tree fn = OVL_CURRENT (fns);
3078 if (TREE_CODE (fn) == TEMPLATE_DECL)
3079 add_template_conv_candidate
3080 (&candidates, fn, obj, args, totype,
3081 /*access_path=*/NULL_TREE,
3082 /*conversion_path=*/NULL_TREE);
3084 add_conv_candidate (&candidates, fn, obj, args,
3085 /*conversion_path=*/NULL_TREE,
3086 /*access_path=*/NULL_TREE);
3090 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3093 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3094 print_z_candidates (candidates);
3095 result = error_mark_node;
3099 cand = tourney (candidates);
3102 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
3103 print_z_candidates (candidates);
3104 result = error_mark_node;
3106 /* Since cand->fn will be a type, not a function, for a conversion
3107 function, we must be careful not to unconditionally look at
3109 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3110 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3111 result = build_over_call (cand, LOOKUP_NORMAL);
3114 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
3115 obj = convert_from_reference (obj);
3116 result = build_function_call (obj, args);
3120 /* Free all the conversions we allocated. */
3121 obstack_free (&conversion_obstack, p);
3127 op_error (enum tree_code code, enum tree_code code2,
3128 tree arg1, tree arg2, tree arg3, const char *problem)
3132 if (code == MODIFY_EXPR)
3133 opname = assignment_operator_name_info[code2].name;
3135 opname = operator_name_info[code].name;
3140 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3141 problem, arg1, arg2, arg3);
3144 case POSTINCREMENT_EXPR:
3145 case POSTDECREMENT_EXPR:
3146 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3150 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3155 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3160 error ("%s for %<operator%s%> in %<%E %s %E%>",
3161 problem, opname, arg1, opname, arg2);
3163 error ("%s for %<operator%s%> in %<%s%E%>",
3164 problem, opname, opname, arg1);
3169 /* Return the implicit conversion sequence that could be used to
3170 convert E1 to E2 in [expr.cond]. */
3173 conditional_conversion (tree e1, tree e2)
3175 tree t1 = non_reference (TREE_TYPE (e1));
3176 tree t2 = non_reference (TREE_TYPE (e2));
3182 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3183 implicitly converted (clause _conv_) to the type "reference to
3184 T2", subject to the constraint that in the conversion the
3185 reference must bind directly (_dcl.init.ref_) to E1. */
3186 if (real_lvalue_p (e2))
3188 conv = implicit_conversion (build_reference_type (t2),
3192 LOOKUP_NO_TEMP_BIND);
3199 If E1 and E2 have class type, and the underlying class types are
3200 the same or one is a base class of the other: E1 can be converted
3201 to match E2 if the class of T2 is the same type as, or a base
3202 class of, the class of T1, and the cv-qualification of T2 is the
3203 same cv-qualification as, or a greater cv-qualification than, the
3204 cv-qualification of T1. If the conversion is applied, E1 is
3205 changed to an rvalue of type T2 that still refers to the original
3206 source class object (or the appropriate subobject thereof). */
3207 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3208 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3210 if (good_base && at_least_as_qualified_p (t2, t1))
3212 conv = build_identity_conv (t1, e1);
3213 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3214 TYPE_MAIN_VARIANT (t2)))
3215 conv = build_conv (ck_base, t2, conv);
3217 conv = build_conv (ck_rvalue, t2, conv);
3226 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3227 converted to the type that expression E2 would have if E2 were
3228 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3229 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3233 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3234 arguments to the conditional expression. */
3237 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3241 tree result = NULL_TREE;
3242 tree result_type = NULL_TREE;
3243 bool lvalue_p = true;
3244 struct z_candidate *candidates = 0;
3245 struct z_candidate *cand;
3248 /* As a G++ extension, the second argument to the conditional can be
3249 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3250 c'.) If the second operand is omitted, make sure it is
3251 calculated only once. */
3255 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3257 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3258 if (real_lvalue_p (arg1))
3259 arg2 = arg1 = stabilize_reference (arg1);
3261 arg2 = arg1 = save_expr (arg1);
3266 The first expr ession is implicitly converted to bool (clause
3268 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3270 /* If something has already gone wrong, just pass that fact up the
3272 if (error_operand_p (arg1)
3273 || error_operand_p (arg2)
3274 || error_operand_p (arg3))
3275 return error_mark_node;
3279 If either the second or the third operand has type (possibly
3280 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3281 array-to-pointer (_conv.array_), and function-to-pointer
3282 (_conv.func_) standard conversions are performed on the second
3283 and third operands. */
3284 arg2_type = unlowered_expr_type (arg2);
3285 arg3_type = unlowered_expr_type (arg3);
3286 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3288 /* Do the conversions. We don't these for `void' type arguments
3289 since it can't have any effect and since decay_conversion
3290 does not handle that case gracefully. */
3291 if (!VOID_TYPE_P (arg2_type))
3292 arg2 = decay_conversion (arg2);
3293 if (!VOID_TYPE_P (arg3_type))
3294 arg3 = decay_conversion (arg3);
3295 arg2_type = TREE_TYPE (arg2);
3296 arg3_type = TREE_TYPE (arg3);
3300 One of the following shall hold:
3302 --The second or the third operand (but not both) is a
3303 throw-expression (_except.throw_); the result is of the
3304 type of the other and is an rvalue.
3306 --Both the second and the third operands have type void; the
3307 result is of type void and is an rvalue.
3309 We must avoid calling force_rvalue for expressions of type
3310 "void" because it will complain that their value is being
3312 if (TREE_CODE (arg2) == THROW_EXPR
3313 && TREE_CODE (arg3) != THROW_EXPR)
3315 if (!VOID_TYPE_P (arg3_type))
3316 arg3 = force_rvalue (arg3);
3317 arg3_type = TREE_TYPE (arg3);
3318 result_type = arg3_type;
3320 else if (TREE_CODE (arg2) != THROW_EXPR
3321 && TREE_CODE (arg3) == THROW_EXPR)
3323 if (!VOID_TYPE_P (arg2_type))
3324 arg2 = force_rvalue (arg2);
3325 arg2_type = TREE_TYPE (arg2);
3326 result_type = arg2_type;
3328 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3329 result_type = void_type_node;
3332 if (VOID_TYPE_P (arg2_type))
3333 error ("second operand to the conditional operator "
3334 "is of type %<void%>, "
3335 "but the third operand is neither a throw-expression "
3336 "nor of type %<void%>");
3338 error ("third operand to the conditional operator "
3339 "is of type %<void%>, "
3340 "but the second operand is neither a throw-expression "
3341 "nor of type %<void%>");
3342 return error_mark_node;
3346 goto valid_operands;
3350 Otherwise, if the second and third operand have different types,
3351 and either has (possibly cv-qualified) class type, an attempt is
3352 made to convert each of those operands to the type of the other. */
3353 else if (!same_type_p (arg2_type, arg3_type)
3354 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3359 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3360 p = conversion_obstack_alloc (0);
3362 conv2 = conditional_conversion (arg2, arg3);
3363 conv3 = conditional_conversion (arg3, arg2);
3367 If both can be converted, or one can be converted but the
3368 conversion is ambiguous, the program is ill-formed. If
3369 neither can be converted, the operands are left unchanged and
3370 further checking is performed as described below. If exactly
3371 one conversion is possible, that conversion is applied to the
3372 chosen operand and the converted operand is used in place of
3373 the original operand for the remainder of this section. */
3374 if ((conv2 && !conv2->bad_p
3375 && conv3 && !conv3->bad_p)
3376 || (conv2 && conv2->kind == ck_ambig)
3377 || (conv3 && conv3->kind == ck_ambig))
3379 error ("operands to ?: have different types %qT and %qT",
3380 arg2_type, arg3_type);
3381 result = error_mark_node;
3383 else if (conv2 && (!conv2->bad_p || !conv3))
3385 arg2 = convert_like (conv2, arg2);
3386 arg2 = convert_from_reference (arg2);
3387 arg2_type = TREE_TYPE (arg2);
3388 /* Even if CONV2 is a valid conversion, the result of the
3389 conversion may be invalid. For example, if ARG3 has type
3390 "volatile X", and X does not have a copy constructor
3391 accepting a "volatile X&", then even if ARG2 can be
3392 converted to X, the conversion will fail. */
3393 if (error_operand_p (arg2))
3394 result = error_mark_node;
3396 else if (conv3 && (!conv3->bad_p || !conv2))
3398 arg3 = convert_like (conv3, arg3);
3399 arg3 = convert_from_reference (arg3);
3400 arg3_type = TREE_TYPE (arg3);
3401 if (error_operand_p (arg3))
3402 result = error_mark_node;
3405 /* Free all the conversions we allocated. */
3406 obstack_free (&conversion_obstack, p);
3411 /* If, after the conversion, both operands have class type,
3412 treat the cv-qualification of both operands as if it were the
3413 union of the cv-qualification of the operands.
3415 The standard is not clear about what to do in this
3416 circumstance. For example, if the first operand has type
3417 "const X" and the second operand has a user-defined
3418 conversion to "volatile X", what is the type of the second
3419 operand after this step? Making it be "const X" (matching
3420 the first operand) seems wrong, as that discards the
3421 qualification without actually performing a copy. Leaving it
3422 as "volatile X" seems wrong as that will result in the
3423 conditional expression failing altogether, even though,
3424 according to this step, the one operand could be converted to
3425 the type of the other. */
3426 if ((conv2 || conv3)
3427 && CLASS_TYPE_P (arg2_type)
3428 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3429 arg2_type = arg3_type =
3430 cp_build_qualified_type (arg2_type,
3431 TYPE_QUALS (arg2_type)
3432 | TYPE_QUALS (arg3_type));
3437 If the second and third operands are lvalues and have the same
3438 type, the result is of that type and is an lvalue. */
3439 if (real_lvalue_p (arg2)
3440 && real_lvalue_p (arg3)
3441 && same_type_p (arg2_type, arg3_type))
3443 result_type = arg2_type;
3444 goto valid_operands;
3449 Otherwise, the result is an rvalue. If the second and third
3450 operand do not have the same type, and either has (possibly
3451 cv-qualified) class type, overload resolution is used to
3452 determine the conversions (if any) to be applied to the operands
3453 (_over.match.oper_, _over.built_). */
3455 if (!same_type_p (arg2_type, arg3_type)
3456 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3462 /* Rearrange the arguments so that add_builtin_candidate only has
3463 to know about two args. In build_builtin_candidates, the
3464 arguments are unscrambled. */
3468 add_builtin_candidates (&candidates,
3471 ansi_opname (COND_EXPR),
3477 If the overload resolution fails, the program is
3479 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3482 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3483 print_z_candidates (candidates);
3484 return error_mark_node;
3486 cand = tourney (candidates);
3489 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3490 print_z_candidates (candidates);
3491 return error_mark_node;
3496 Otherwise, the conversions thus determined are applied, and
3497 the converted operands are used in place of the original
3498 operands for the remainder of this section. */
3499 conv = cand->convs[0];
3500 arg1 = convert_like (conv, arg1);
3501 conv = cand->convs[1];
3502 arg2 = convert_like (conv, arg2);
3503 conv = cand->convs[2];
3504 arg3 = convert_like (conv, arg3);
3509 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3510 and function-to-pointer (_conv.func_) standard conversions are
3511 performed on the second and third operands.
3513 We need to force the lvalue-to-rvalue conversion here for class types,
3514 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3515 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3518 arg2 = force_rvalue (arg2);
3519 if (!CLASS_TYPE_P (arg2_type))
3520 arg2_type = TREE_TYPE (arg2);
3522 arg3 = force_rvalue (arg3);
3523 if (!CLASS_TYPE_P (arg2_type))
3524 arg3_type = TREE_TYPE (arg3);
3526 if (arg2 == error_mark_node || arg3 == error_mark_node)
3527 return error_mark_node;
3531 After those conversions, one of the following shall hold:
3533 --The second and third operands have the same type; the result is of
3535 if (same_type_p (arg2_type, arg3_type))
3536 result_type = arg2_type;
3539 --The second and third operands have arithmetic or enumeration
3540 type; the usual arithmetic conversions are performed to bring
3541 them to a common type, and the result is of that type. */
3542 else if ((ARITHMETIC_TYPE_P (arg2_type)
3543 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3544 && (ARITHMETIC_TYPE_P (arg3_type)
3545 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3547 /* In this case, there is always a common type. */
3548 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3551 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3552 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3553 warning (0, "enumeral mismatch in conditional expression: %qT vs %qT",
3554 arg2_type, arg3_type);
3555 else if (extra_warnings
3556 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3557 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3558 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3559 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3560 warning (0, "enumeral and non-enumeral type in conditional expression");
3562 arg2 = perform_implicit_conversion (result_type, arg2);
3563 arg3 = perform_implicit_conversion (result_type, arg3);
3567 --The second and third operands have pointer type, or one has
3568 pointer type and the other is a null pointer constant; pointer
3569 conversions (_conv.ptr_) and qualification conversions
3570 (_conv.qual_) are performed to bring them to their composite
3571 pointer type (_expr.rel_). The result is of the composite
3574 --The second and third operands have pointer to member type, or
3575 one has pointer to member type and the other is a null pointer
3576 constant; pointer to member conversions (_conv.mem_) and
3577 qualification conversions (_conv.qual_) are performed to bring
3578 them to a common type, whose cv-qualification shall match the
3579 cv-qualification of either the second or the third operand.
3580 The result is of the common type. */
3581 else if ((null_ptr_cst_p (arg2)
3582 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3583 || (null_ptr_cst_p (arg3)
3584 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3585 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3586 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3587 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3589 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3590 arg3, "conditional expression");
3591 if (result_type == error_mark_node)
3592 return error_mark_node;
3593 arg2 = perform_implicit_conversion (result_type, arg2);
3594 arg3 = perform_implicit_conversion (result_type, arg3);
3599 error ("operands to ?: have different types %qT and %qT",
3600 arg2_type, arg3_type);
3601 return error_mark_node;
3605 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3607 /* We can't use result_type below, as fold might have returned a
3612 /* Expand both sides into the same slot, hopefully the target of
3613 the ?: expression. We used to check for TARGET_EXPRs here,
3614 but now we sometimes wrap them in NOP_EXPRs so the test would
3616 if (CLASS_TYPE_P (TREE_TYPE (result)))
3617 result = get_target_expr (result);
3618 /* If this expression is an rvalue, but might be mistaken for an
3619 lvalue, we must add a NON_LVALUE_EXPR. */
3620 result = rvalue (result);
3626 /* OPERAND is an operand to an expression. Perform necessary steps
3627 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3631 prep_operand (tree operand)
3635 if (CLASS_TYPE_P (TREE_TYPE (operand))
3636 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3637 /* Make sure the template type is instantiated now. */
3638 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3644 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3645 OVERLOAD) to the CANDIDATES, returning an updated list of
3646 CANDIDATES. The ARGS are the arguments provided to the call,
3647 without any implicit object parameter. The EXPLICIT_TARGS are
3648 explicit template arguments provided. TEMPLATE_ONLY is true if
3649 only template functions should be considered. CONVERSION_PATH,
3650 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3653 add_candidates (tree fns, tree args,
3654 tree explicit_targs, bool template_only,
3655 tree conversion_path, tree access_path,
3657 struct z_candidate **candidates)
3660 tree non_static_args;
3662 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3663 /* Delay creating the implicit this parameter until it is needed. */
3664 non_static_args = NULL_TREE;
3671 fn = OVL_CURRENT (fns);
3672 /* Figure out which set of arguments to use. */
3673 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3675 /* If this function is a non-static member, prepend the implicit
3676 object parameter. */
3677 if (!non_static_args)
3678 non_static_args = tree_cons (NULL_TREE,
3679 build_this (TREE_VALUE (args)),
3681 fn_args = non_static_args;
3684 /* Otherwise, just use the list of arguments provided. */
3687 if (TREE_CODE (fn) == TEMPLATE_DECL)
3688 add_template_candidate (candidates,
3698 else if (!template_only)
3699 add_function_candidate (candidates,
3706 fns = OVL_NEXT (fns);
3711 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3714 struct z_candidate *candidates = 0, *cand;
3715 tree arglist, fnname;
3717 tree result = NULL_TREE;
3718 bool result_valid_p = false;
3719 enum tree_code code2 = NOP_EXPR;
3724 bool expl_eq_arg1 = false;
3726 if (error_operand_p (arg1)
3727 || error_operand_p (arg2)
3728 || error_operand_p (arg3))
3729 return error_mark_node;
3731 if (code == MODIFY_EXPR)
3733 code2 = TREE_CODE (arg3);
3735 fnname = ansi_assopname (code2);
3738 fnname = ansi_opname (code);
3740 arg1 = prep_operand (arg1);
3746 case VEC_DELETE_EXPR:
3748 /* Use build_op_new_call and build_op_delete_call instead. */
3752 return build_object_call (arg1, arg2);
3754 case TRUTH_ORIF_EXPR:
3755 case TRUTH_ANDIF_EXPR:
3756 case TRUTH_AND_EXPR:
3758 if (COMPARISON_CLASS_P (arg1))
3759 expl_eq_arg1 = true;
3764 arg2 = prep_operand (arg2);
3765 arg3 = prep_operand (arg3);
3767 if (code == COND_EXPR)
3769 if (arg2 == NULL_TREE
3770 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3771 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3772 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3773 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3776 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3777 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3780 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3781 arg2 = integer_zero_node;
3783 arglist = NULL_TREE;
3785 arglist = tree_cons (NULL_TREE, arg3, arglist);
3787 arglist = tree_cons (NULL_TREE, arg2, arglist);
3788 arglist = tree_cons (NULL_TREE, arg1, arglist);
3790 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3791 p = conversion_obstack_alloc (0);
3793 /* Add namespace-scope operators to the list of functions to
3795 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3796 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3797 flags, &candidates);
3798 /* Add class-member operators to the candidate set. */
3799 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3803 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3804 if (fns == error_mark_node)
3806 result = error_mark_node;
3807 goto user_defined_result_ready;
3810 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3812 BASELINK_BINFO (fns),
3813 TYPE_BINFO (TREE_TYPE (arg1)),
3814 flags, &candidates);
3817 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3818 to know about two args; a builtin candidate will always have a first
3819 parameter of type bool. We'll handle that in
3820 build_builtin_candidate. */
3821 if (code == COND_EXPR)
3831 args[2] = NULL_TREE;
3834 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3840 /* For these, the built-in candidates set is empty
3841 [over.match.oper]/3. We don't want non-strict matches
3842 because exact matches are always possible with built-in
3843 operators. The built-in candidate set for COMPONENT_REF
3844 would be empty too, but since there are no such built-in
3845 operators, we accept non-strict matches for them. */
3850 strict_p = pedantic;
3854 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3859 case POSTINCREMENT_EXPR:
3860 case POSTDECREMENT_EXPR:
3861 /* Look for an `operator++ (int)'. If they didn't have
3862 one, then we fall back to the old way of doing things. */
3863 if (flags & LOOKUP_COMPLAIN)
3864 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3865 "trying prefix operator instead",
3867 operator_name_info[code].name);
3868 if (code == POSTINCREMENT_EXPR)
3869 code = PREINCREMENT_EXPR;
3871 code = PREDECREMENT_EXPR;
3872 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3876 /* The caller will deal with these. */
3881 result_valid_p = true;
3885 if (flags & LOOKUP_COMPLAIN)
3887 op_error (code, code2, arg1, arg2, arg3, "no match");
3888 print_z_candidates (candidates);
3890 result = error_mark_node;
3896 cand = tourney (candidates);
3899 if (flags & LOOKUP_COMPLAIN)
3901 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3902 print_z_candidates (candidates);
3904 result = error_mark_node;
3906 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3909 *overloaded_p = true;
3911 result = build_over_call (cand, LOOKUP_NORMAL);
3915 /* Give any warnings we noticed during overload resolution. */
3918 struct candidate_warning *w;
3919 for (w = cand->warnings; w; w = w->next)
3920 joust (cand, w->loser, 1);
3923 /* Check for comparison of different enum types. */
3932 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3933 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3934 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3935 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3937 warning (0, "comparison between %q#T and %q#T",
3938 TREE_TYPE (arg1), TREE_TYPE (arg2));
3945 /* We need to strip any leading REF_BIND so that bitfields
3946 don't cause errors. This should not remove any important
3947 conversions, because builtins don't apply to class
3948 objects directly. */
3949 conv = cand->convs[0];
3950 if (conv->kind == ck_ref_bind)
3951 conv = conv->u.next;
3952 arg1 = convert_like (conv, arg1);
3955 conv = cand->convs[1];
3956 if (conv->kind == ck_ref_bind)
3957 conv = conv->u.next;
3958 arg2 = convert_like (conv, arg2);
3962 conv = cand->convs[2];
3963 if (conv->kind == ck_ref_bind)
3964 conv = conv->u.next;
3965 arg3 = convert_like (conv, arg3);
3970 warn_logical_operator (code, arg1, arg2);
3971 expl_eq_arg1 = true;
3976 user_defined_result_ready:
3978 /* Free all the conversions we allocated. */
3979 obstack_free (&conversion_obstack, p);
3981 if (result || result_valid_p)
3988 return build_modify_expr (arg1, code2, arg2);
3991 return build_indirect_ref (arg1, "unary *");
3993 case TRUTH_ANDIF_EXPR:
3994 case TRUTH_ORIF_EXPR:
3995 case TRUTH_AND_EXPR:
3998 warn_logical_operator (code, arg1, arg2);
4002 case TRUNC_DIV_EXPR:
4013 case TRUNC_MOD_EXPR:
4017 return cp_build_binary_op (code, arg1, arg2);
4019 case UNARY_PLUS_EXPR:
4022 case TRUTH_NOT_EXPR:
4023 case PREINCREMENT_EXPR:
4024 case POSTINCREMENT_EXPR:
4025 case PREDECREMENT_EXPR:
4026 case POSTDECREMENT_EXPR:
4029 return build_unary_op (code, arg1, candidates != 0);
4032 return build_array_ref (arg1, arg2);
4035 return build_conditional_expr (arg1, arg2, arg3);
4038 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
4040 /* The caller will deal with these. */
4052 /* Build a call to operator delete. This has to be handled very specially,
4053 because the restrictions on what signatures match are different from all
4054 other call instances. For a normal delete, only a delete taking (void *)
4055 or (void *, size_t) is accepted. For a placement delete, only an exact
4056 match with the placement new is accepted.
4058 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4059 ADDR is the pointer to be deleted.
4060 SIZE is the size of the memory block to be deleted.
4061 GLOBAL_P is true if the delete-expression should not consider
4062 class-specific delete operators.
4063 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4065 If this call to "operator delete" is being generated as part to
4066 deallocate memory allocated via a new-expression (as per [expr.new]
4067 which requires that if the initialization throws an exception then
4068 we call a deallocation function), then ALLOC_FN is the allocation
4072 build_op_delete_call (enum tree_code code, tree addr, tree size,
4073 bool global_p, tree placement,
4076 tree fn = NULL_TREE;
4077 tree fns, fnname, argtypes, type;
4080 if (addr == error_mark_node)
4081 return error_mark_node;
4083 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4085 fnname = ansi_opname (code);
4087 if (CLASS_TYPE_P (type)
4088 && COMPLETE_TYPE_P (complete_type (type))
4092 If the result of the lookup is ambiguous or inaccessible, or if
4093 the lookup selects a placement deallocation function, the
4094 program is ill-formed.
4096 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4098 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4099 if (fns == error_mark_node)
4100 return error_mark_node;
4105 if (fns == NULL_TREE)
4106 fns = lookup_name_nonclass (fnname);
4108 /* Strip const and volatile from addr. */
4109 addr = cp_convert (ptr_type_node, addr);
4113 /* Get the parameter types for the allocation function that is
4115 gcc_assert (alloc_fn != NULL_TREE);
4116 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4120 /* First try it without the size argument. */
4121 argtypes = void_list_node;
4124 /* We make two tries at finding a matching `operator delete'. On
4125 the first pass, we look for a one-operator (or placement)
4126 operator delete. If we're not doing placement delete, then on
4127 the second pass we look for a two-argument delete. */
4128 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4130 /* Go through the `operator delete' functions looking for one
4131 with a matching type. */
4132 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4138 /* The first argument must be "void *". */
4139 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4140 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4143 /* On the first pass, check the rest of the arguments. */
4149 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4157 /* On the second pass, look for a function with exactly two
4158 arguments: "void *" and "size_t". */
4160 /* For "operator delete(void *, ...)" there will be
4161 no second argument, but we will not get an exact
4164 && same_type_p (TREE_VALUE (t), size_type_node)
4165 && TREE_CHAIN (t) == void_list_node)
4169 /* If we found a match, we're done. */
4174 /* If we have a matching function, call it. */
4177 /* Make sure we have the actual function, and not an
4179 fn = OVL_CURRENT (fn);
4181 /* If the FN is a member function, make sure that it is
4183 if (DECL_CLASS_SCOPE_P (fn))
4184 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4188 /* The placement args might not be suitable for overload
4189 resolution at this point, so build the call directly. */
4190 int nargs = call_expr_nargs (placement);
4191 tree *argarray = (tree *) alloca (nargs * sizeof (tree));
4194 for (i = 1; i < nargs; i++)
4195 argarray[i] = CALL_EXPR_ARG (placement, i);
4197 return build_cxx_call (fn, nargs, argarray);
4203 args = tree_cons (NULL_TREE, addr, NULL_TREE);
4205 args = tree_cons (NULL_TREE, addr,
4206 build_tree_list (NULL_TREE, size));
4207 return build_function_call (fn, args);
4213 If no unambiguous matching deallocation function can be found,
4214 propagating the exception does not cause the object's memory to
4219 warning (0, "no corresponding deallocation function for `%D'",
4224 error ("no suitable %<operator %s%> for %qT",
4225 operator_name_info[(int)code].name, type);
4226 return error_mark_node;
4229 /* If the current scope isn't allowed to access DECL along
4230 BASETYPE_PATH, give an error. The most derived class in
4231 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4232 the declaration to use in the error diagnostic. */
4235 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4237 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4239 if (!accessible_p (basetype_path, decl, true))
4241 if (TREE_PRIVATE (decl))
4242 error ("%q+#D is private", diag_decl);
4243 else if (TREE_PROTECTED (decl))
4244 error ("%q+#D is protected", diag_decl);
4246 error ("%q+#D is inaccessible", diag_decl);
4247 error ("within this context");
4254 /* Check that a callable constructor to initialize a temporary of
4255 TYPE from an EXPR exists. */
4258 check_constructor_callable (tree type, tree expr)
4260 build_special_member_call (NULL_TREE,
4261 complete_ctor_identifier,
4262 build_tree_list (NULL_TREE, expr),
4264 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4265 | LOOKUP_NO_CONVERSION
4266 | LOOKUP_CONSTRUCTOR_CALLABLE);
4269 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4270 bitwise or of LOOKUP_* values. If any errors are warnings are
4271 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4272 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4276 build_temp (tree expr, tree type, int flags,
4277 diagnostic_fn_t *diagnostic_fn)
4281 savew = warningcount, savee = errorcount;
4282 expr = build_special_member_call (NULL_TREE,
4283 complete_ctor_identifier,
4284 build_tree_list (NULL_TREE, expr),
4286 if (warningcount > savew)
4287 *diagnostic_fn = warning0;
4288 else if (errorcount > savee)
4289 *diagnostic_fn = error;
4291 *diagnostic_fn = NULL;
4295 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4296 EXPR is implicitly converted to type TOTYPE.
4297 FN and ARGNUM are used for diagnostics. */
4300 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
4302 tree t = non_reference (totype);
4304 /* Issue warnings about peculiar, but valid, uses of NULL. */
4305 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
4308 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4311 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4314 /* Issue warnings if "false" is converted to a NULL pointer */
4315 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
4316 warning (OPT_Wconversion,
4317 "converting %<false%> to pointer type for argument %P of %qD",
4321 /* Perform the conversions in CONVS on the expression EXPR. FN and
4322 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4323 indicates the `this' argument of a method. INNER is nonzero when
4324 being called to continue a conversion chain. It is negative when a
4325 reference binding will be applied, positive otherwise. If
4326 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4327 conversions will be emitted if appropriate. If C_CAST_P is true,
4328 this conversion is coming from a C-style cast; in that case,
4329 conversions to inaccessible bases are permitted. */
4332 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4333 int inner, bool issue_conversion_warnings,
4336 tree totype = convs->type;
4337 diagnostic_fn_t diagnostic_fn;
4340 && convs->kind != ck_user
4341 && convs->kind != ck_ambig
4342 && convs->kind != ck_ref_bind)
4344 conversion *t = convs;
4345 for (; t; t = convs->u.next)
4347 if (t->kind == ck_user || !t->bad_p)
4349 expr = convert_like_real (t, expr, fn, argnum, 1,
4350 /*issue_conversion_warnings=*/false,
4351 /*c_cast_p=*/false);
4354 else if (t->kind == ck_ambig)
4355 return convert_like_real (t, expr, fn, argnum, 1,
4356 /*issue_conversion_warnings=*/false,
4357 /*c_cast_p=*/false);
4358 else if (t->kind == ck_identity)
4361 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4363 pedwarn (" initializing argument %P of %qD", argnum, fn);
4364 return cp_convert (totype, expr);
4367 if (issue_conversion_warnings)
4368 conversion_null_warnings (totype, expr, fn, argnum);
4370 switch (convs->kind)
4374 struct z_candidate *cand = convs->cand;
4375 tree convfn = cand->fn;
4377 expr = build_over_call (cand, LOOKUP_NORMAL);
4379 /* If this is a constructor or a function returning an aggr type,
4380 we need to build up a TARGET_EXPR. */
4381 if (DECL_CONSTRUCTOR_P (convfn))
4382 expr = build_cplus_new (totype, expr);
4384 /* The result of the call is then used to direct-initialize the object
4385 that is the destination of the copy-initialization. [dcl.init]
4387 Note that this step is not reflected in the conversion sequence;
4388 it affects the semantics when we actually perform the
4389 conversion, but is not considered during overload resolution.
4391 If the target is a class, that means call a ctor. */
4392 if (IS_AGGR_TYPE (totype)
4393 && (inner >= 0 || !lvalue_p (expr)))
4397 /* Core issue 84, now a DR, says that we don't
4398 allow UDCs for these args (which deliberately
4399 breaks copy-init of an auto_ptr<Base> from an
4400 auto_ptr<Derived>). */
4401 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4408 (" initializing argument %P of %qD from result of %qD",
4409 argnum, fn, convfn);
4412 (" initializing temporary from result of %qD", convfn);
4414 expr = build_cplus_new (totype, expr);
4419 if (type_unknown_p (expr))
4420 expr = instantiate_type (totype, expr, tf_warning_or_error);
4421 /* Convert a constant to its underlying value, unless we are
4422 about to bind it to a reference, in which case we need to
4423 leave it as an lvalue. */
4425 expr = decl_constant_value (expr);
4426 if (convs->check_copy_constructor_p)
4427 check_constructor_callable (totype, expr);
4430 /* Call build_user_type_conversion again for the error. */
4431 return build_user_type_conversion
4432 (totype, convs->u.expr, LOOKUP_NORMAL);
4438 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4439 convs->kind == ck_ref_bind ? -1 : 1,
4440 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
4442 if (expr == error_mark_node)
4443 return error_mark_node;
4445 switch (convs->kind)
4448 expr = convert_bitfield_to_declared_type (expr);
4449 if (! IS_AGGR_TYPE (totype))
4451 /* Else fall through. */
4453 if (convs->kind == ck_base && !convs->need_temporary_p)
4455 /* We are going to bind a reference directly to a base-class
4456 subobject of EXPR. */
4457 if (convs->check_copy_constructor_p)
4458 check_constructor_callable (TREE_TYPE (expr), expr);
4459 /* Build an expression for `*((base*) &expr)'. */
4460 expr = build_unary_op (ADDR_EXPR, expr, 0);
4461 expr = convert_to_base (expr, build_pointer_type (totype),
4462 !c_cast_p, /*nonnull=*/true);
4463 expr = build_indirect_ref (expr, "implicit conversion");
4467 /* Copy-initialization where the cv-unqualified version of the source
4468 type is the same class as, or a derived class of, the class of the
4469 destination [is treated as direct-initialization]. [dcl.init] */
4470 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4472 if (diagnostic_fn && fn)
4473 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4474 return build_cplus_new (totype, expr);
4478 tree ref_type = totype;
4480 /* If necessary, create a temporary.
4482 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
4483 that need temporaries, even when their types are reference
4484 compatible with the type of reference being bound, so the
4485 upcoming call to build_unary_op (ADDR_EXPR, expr, ...)
4487 if (convs->need_temporary_p
4488 || TREE_CODE (expr) == CONSTRUCTOR
4489 || TREE_CODE (expr) == VA_ARG_EXPR)
4491 tree type = convs->u.next->type;
4492 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4494 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type))
4495 && !TYPE_REF_IS_RVALUE (ref_type))
4497 /* If the reference is volatile or non-const, we
4498 cannot create a temporary. */
4499 if (lvalue & clk_bitfield)
4500 error ("cannot bind bitfield %qE to %qT",
4502 else if (lvalue & clk_packed)
4503 error ("cannot bind packed field %qE to %qT",
4506 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4507 return error_mark_node;
4509 /* If the source is a packed field, and we must use a copy
4510 constructor, then building the target expr will require
4511 binding the field to the reference parameter to the
4512 copy constructor, and we'll end up with an infinite
4513 loop. If we can use a bitwise copy, then we'll be
4515 if ((lvalue & clk_packed)
4516 && CLASS_TYPE_P (type)
4517 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4519 error ("cannot bind packed field %qE to %qT",
4521 return error_mark_node;
4523 expr = build_target_expr_with_type (expr, type);
4526 /* Take the address of the thing to which we will bind the
4528 expr = build_unary_op (ADDR_EXPR, expr, 1);
4529 if (expr == error_mark_node)
4530 return error_mark_node;
4532 /* Convert it to a pointer to the type referred to by the
4533 reference. This will adjust the pointer if a derived to
4534 base conversion is being performed. */
4535 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4537 /* Convert the pointer to the desired reference type. */
4538 return build_nop (ref_type, expr);
4542 return decay_conversion (expr);
4545 /* Warn about deprecated conversion if appropriate. */
4546 string_conv_p (totype, expr, 1);
4551 expr = convert_to_base (expr, totype, !c_cast_p,
4553 return build_nop (totype, expr);
4556 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4563 if (issue_conversion_warnings)
4564 expr = convert_and_check (totype, expr);
4566 expr = convert (totype, expr);
4571 /* Build a call to __builtin_trap. */
4574 call_builtin_trap (void)
4576 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4578 gcc_assert (fn != NULL);
4579 fn = build_call_n (fn, 0);
4583 /* ARG is being passed to a varargs function. Perform any conversions
4584 required. Return the converted value. */
4587 convert_arg_to_ellipsis (tree arg)
4591 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4592 standard conversions are performed. */
4593 arg = decay_conversion (arg);
4596 If the argument has integral or enumeration type that is subject
4597 to the integral promotions (_conv.prom_), or a floating point
4598 type that is subject to the floating point promotion
4599 (_conv.fpprom_), the value of the argument is converted to the
4600 promoted type before the call. */
4601 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4602 && (TYPE_PRECISION (TREE_TYPE (arg))
4603 < TYPE_PRECISION (double_type_node)))
4604 arg = convert_to_real (double_type_node, arg);
4605 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4606 arg = perform_integral_promotions (arg);
4608 arg = require_complete_type (arg);
4610 if (arg != error_mark_node
4611 && !pod_type_p (TREE_TYPE (arg)))
4613 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4614 here and do a bitwise copy, but now cp_expr_size will abort if we
4616 If the call appears in the context of a sizeof expression,
4617 there is no need to emit a warning, since the expression won't be
4618 evaluated. We keep the builtin_trap just as a safety check. */
4619 if (!skip_evaluation)
4620 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4621 "call will abort at runtime", TREE_TYPE (arg));
4622 arg = call_builtin_trap ();
4623 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4630 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4633 build_x_va_arg (tree expr, tree type)
4635 if (processing_template_decl)
4636 return build_min (VA_ARG_EXPR, type, expr);
4638 type = complete_type_or_else (type, NULL_TREE);
4640 if (expr == error_mark_node || !type)
4641 return error_mark_node;
4643 if (! pod_type_p (type))
4645 /* Remove reference types so we don't ICE later on. */
4646 tree type1 = non_reference (type);
4647 /* Undefined behavior [expr.call] 5.2.2/7. */
4648 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4649 "call will abort at runtime", type);
4650 expr = convert (build_pointer_type (type1), null_node);
4651 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4652 call_builtin_trap (), expr);
4653 expr = build_indirect_ref (expr, NULL);
4657 return build_va_arg (expr, type);
4660 /* TYPE has been given to va_arg. Apply the default conversions which
4661 would have happened when passed via ellipsis. Return the promoted
4662 type, or the passed type if there is no change. */
4665 cxx_type_promotes_to (tree type)
4669 /* Perform the array-to-pointer and function-to-pointer
4671 type = type_decays_to (type);
4673 promote = type_promotes_to (type);
4674 if (same_type_p (type, promote))
4680 /* ARG is a default argument expression being passed to a parameter of
4681 the indicated TYPE, which is a parameter to FN. Do any required
4682 conversions. Return the converted value. */
4685 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4687 /* If the ARG is an unparsed default argument expression, the
4688 conversion cannot be performed. */
4689 if (TREE_CODE (arg) == DEFAULT_ARG)
4691 error ("the default argument for parameter %d of %qD has "
4692 "not yet been parsed",
4694 return error_mark_node;
4697 if (fn && DECL_TEMPLATE_INFO (fn))
4698 arg = tsubst_default_argument (fn, type, arg);
4700 arg = break_out_target_exprs (arg);
4702 if (TREE_CODE (arg) == CONSTRUCTOR)
4704 arg = digest_init (type, arg);
4705 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4706 "default argument", fn, parmnum);
4710 /* We must make a copy of ARG, in case subsequent processing
4711 alters any part of it. For example, during gimplification a
4712 cast of the form (T) &X::f (where "f" is a member function)
4713 will lead to replacing the PTRMEM_CST for &X::f with a
4714 VAR_DECL. We can avoid the copy for constants, since they
4715 are never modified in place. */
4716 if (!CONSTANT_CLASS_P (arg))
4717 arg = unshare_expr (arg);
4718 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4719 "default argument", fn, parmnum);
4720 arg = convert_for_arg_passing (type, arg);
4726 /* Returns the type which will really be used for passing an argument of
4730 type_passed_as (tree type)
4732 /* Pass classes with copy ctors by invisible reference. */
4733 if (TREE_ADDRESSABLE (type))
4735 type = build_reference_type (type);
4736 /* There are no other pointers to this temporary. */
4737 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4739 else if (targetm.calls.promote_prototypes (type)
4740 && INTEGRAL_TYPE_P (type)
4741 && COMPLETE_TYPE_P (type)
4742 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4743 TYPE_SIZE (integer_type_node)))
4744 type = integer_type_node;
4749 /* Actually perform the appropriate conversion. */
4752 convert_for_arg_passing (tree type, tree val)
4756 /* If VAL is a bitfield, then -- since it has already been converted
4757 to TYPE -- it cannot have a precision greater than TYPE.
4759 If it has a smaller precision, we must widen it here. For
4760 example, passing "int f:3;" to a function expecting an "int" will
4761 not result in any conversion before this point.
4763 If the precision is the same we must not risk widening. For
4764 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
4765 often have type "int", even though the C++ type for the field is
4766 "long long". If the value is being passed to a function
4767 expecting an "int", then no conversions will be required. But,
4768 if we call convert_bitfield_to_declared_type, the bitfield will
4769 be converted to "long long". */
4770 bitfield_type = is_bitfield_expr_with_lowered_type (val);
4772 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
4773 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
4775 if (val == error_mark_node)
4777 /* Pass classes with copy ctors by invisible reference. */
4778 else if (TREE_ADDRESSABLE (type))
4779 val = build1 (ADDR_EXPR, build_reference_type (type), val);
4780 else if (targetm.calls.promote_prototypes (type)
4781 && INTEGRAL_TYPE_P (type)
4782 && COMPLETE_TYPE_P (type)
4783 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4784 TYPE_SIZE (integer_type_node)))
4785 val = perform_integral_promotions (val);
4786 if (warn_missing_format_attribute)
4788 tree rhstype = TREE_TYPE (val);
4789 const enum tree_code coder = TREE_CODE (rhstype);
4790 const enum tree_code codel = TREE_CODE (type);
4791 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4793 && check_missing_format_attribute (type, rhstype))
4794 warning (OPT_Wmissing_format_attribute,
4795 "argument of function call might be a candidate for a format attribute");
4800 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4801 which no conversions at all should be done. This is true for some
4802 builtins which don't act like normal functions. */
4805 magic_varargs_p (tree fn)
4807 if (DECL_BUILT_IN (fn))
4808 switch (DECL_FUNCTION_CODE (fn))
4810 case BUILT_IN_CLASSIFY_TYPE:
4811 case BUILT_IN_CONSTANT_P:
4812 case BUILT_IN_NEXT_ARG:
4813 case BUILT_IN_STDARG_START:
4814 case BUILT_IN_VA_START:
4818 return lookup_attribute ("type generic",
4819 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
4825 /* Subroutine of the various build_*_call functions. Overload resolution
4826 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4827 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4828 bitmask of various LOOKUP_* flags which apply to the call itself. */
4831 build_over_call (struct z_candidate *cand, int flags)
4834 tree args = cand->args;
4835 conversion **convs = cand->convs;
4837 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4846 /* In a template, there is no need to perform all of the work that
4847 is normally done. We are only interested in the type of the call
4848 expression, i.e., the return type of the function. Any semantic
4849 errors will be deferred until the template is instantiated. */
4850 if (processing_template_decl)
4854 return_type = TREE_TYPE (TREE_TYPE (fn));
4855 expr = build_call_list (return_type, fn, args);
4856 if (TREE_THIS_VOLATILE (fn) && cfun)
4857 current_function_returns_abnormally = 1;
4858 if (!VOID_TYPE_P (return_type))
4859 require_complete_type (return_type);
4860 return convert_from_reference (expr);
4863 /* Give any warnings we noticed during overload resolution. */
4866 struct candidate_warning *w;
4867 for (w = cand->warnings; w; w = w->next)
4868 joust (cand, w->loser, 1);
4871 if (DECL_FUNCTION_MEMBER_P (fn))
4873 /* If FN is a template function, two cases must be considered.
4878 template <class T> void f();
4880 template <class T> struct B {
4884 struct C : A, B<int> {
4886 using B<int>::g; // #2
4889 In case #1 where `A::f' is a member template, DECL_ACCESS is
4890 recorded in the primary template but not in its specialization.
4891 We check access of FN using its primary template.
4893 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4894 because it is a member of class template B, DECL_ACCESS is
4895 recorded in the specialization `B<int>::g'. We cannot use its
4896 primary template because `B<T>::g' and `B<int>::g' may have
4897 different access. */
4898 if (DECL_TEMPLATE_INFO (fn)
4899 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4900 perform_or_defer_access_check (cand->access_path,
4901 DECL_TI_TEMPLATE (fn), fn);
4903 perform_or_defer_access_check (cand->access_path, fn, fn);
4906 if (args && TREE_CODE (args) != TREE_LIST)
4907 args = build_tree_list (NULL_TREE, args);
4910 /* Find maximum size of vector to hold converted arguments. */
4911 parmlen = list_length (parm);
4912 nargs = list_length (args);
4913 if (parmlen > nargs)
4915 argarray = (tree *) alloca (nargs * sizeof (tree));
4917 /* The implicit parameters to a constructor are not considered by overload
4918 resolution, and must be of the proper type. */
4919 if (DECL_CONSTRUCTOR_P (fn))
4921 argarray[j++] = TREE_VALUE (arg);
4922 arg = TREE_CHAIN (arg);
4923 parm = TREE_CHAIN (parm);
4924 /* We should never try to call the abstract constructor. */
4925 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4927 if (DECL_HAS_VTT_PARM_P (fn))
4929 argarray[j++] = TREE_VALUE (arg);
4930 arg = TREE_CHAIN (arg);
4931 parm = TREE_CHAIN (parm);
4934 /* Bypass access control for 'this' parameter. */
4935 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4937 tree parmtype = TREE_VALUE (parm);
4938 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4942 if (convs[i]->bad_p)
4943 pedwarn ("passing %qT as %<this%> argument of %q#D discards qualifiers",
4944 TREE_TYPE (argtype), fn);
4946 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4947 X is called for an object that is not of type X, or of a type
4948 derived from X, the behavior is undefined.
4950 So we can assume that anything passed as 'this' is non-null, and
4951 optimize accordingly. */
4952 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4953 /* Convert to the base in which the function was declared. */
4954 gcc_assert (cand->conversion_path != NULL_TREE);
4955 converted_arg = build_base_path (PLUS_EXPR,
4957 cand->conversion_path,
4959 /* Check that the base class is accessible. */
4960 if (!accessible_base_p (TREE_TYPE (argtype),
4961 BINFO_TYPE (cand->conversion_path), true))
4962 error ("%qT is not an accessible base of %qT",
4963 BINFO_TYPE (cand->conversion_path),
4964 TREE_TYPE (argtype));
4965 /* If fn was found by a using declaration, the conversion path
4966 will be to the derived class, not the base declaring fn. We
4967 must convert from derived to base. */
4968 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4969 TREE_TYPE (parmtype), ba_unique, NULL);
4970 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4973 argarray[j++] = converted_arg;
4974 parm = TREE_CHAIN (parm);
4975 arg = TREE_CHAIN (arg);
4981 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4983 tree type = TREE_VALUE (parm);
4987 /* Don't make a copy here if build_call is going to. */
4988 if (conv->kind == ck_rvalue
4989 && !TREE_ADDRESSABLE (complete_type (type)))
4990 conv = conv->u.next;
4992 val = convert_like_with_context
4993 (conv, TREE_VALUE (arg), fn, i - is_method);
4995 val = convert_for_arg_passing (type, val);
4996 argarray[j++] = val;
4999 /* Default arguments */
5000 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
5001 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
5002 TREE_PURPOSE (parm),
5005 for (; arg; arg = TREE_CHAIN (arg))
5007 tree a = TREE_VALUE (arg);
5008 if (magic_varargs_p (fn))
5009 /* Do no conversions for magic varargs. */;
5011 a = convert_arg_to_ellipsis (a);
5015 gcc_assert (j <= nargs);
5018 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
5019 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
5021 /* Avoid actually calling copy constructors and copy assignment operators,
5024 if (! flag_elide_constructors)
5025 /* Do things the hard way. */;
5026 else if (cand->num_convs == 1
5027 && (DECL_COPY_CONSTRUCTOR_P (fn)
5028 || DECL_MOVE_CONSTRUCTOR_P (fn)))
5031 arg = argarray[num_artificial_parms_for (fn)];
5033 /* Pull out the real argument, disregarding const-correctness. */
5035 while (TREE_CODE (targ) == NOP_EXPR
5036 || TREE_CODE (targ) == NON_LVALUE_EXPR
5037 || TREE_CODE (targ) == CONVERT_EXPR)
5038 targ = TREE_OPERAND (targ, 0);
5039 if (TREE_CODE (targ) == ADDR_EXPR)
5041 targ = TREE_OPERAND (targ, 0);
5042 if (!same_type_ignoring_top_level_qualifiers_p
5043 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
5052 arg = build_indirect_ref (arg, 0);
5054 /* [class.copy]: the copy constructor is implicitly defined even if
5055 the implementation elided its use. */
5056 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
5059 /* If we're creating a temp and we already have one, don't create a
5060 new one. If we're not creating a temp but we get one, use
5061 INIT_EXPR to collapse the temp into our target. Otherwise, if the
5062 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
5063 temp or an INIT_EXPR otherwise. */
5064 if (integer_zerop (TREE_VALUE (args)))
5066 if (TREE_CODE (arg) == TARGET_EXPR)
5068 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5069 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
5071 else if (TREE_CODE (arg) == TARGET_EXPR
5072 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5074 tree to = stabilize_reference
5075 (build_indirect_ref (TREE_VALUE (args), 0));
5077 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
5081 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
5083 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
5085 tree to = stabilize_reference
5086 (build_indirect_ref (argarray[0], 0));
5087 tree type = TREE_TYPE (to);
5088 tree as_base = CLASSTYPE_AS_BASE (type);
5091 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
5093 arg = build_indirect_ref (arg, 0);
5094 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
5098 /* We must only copy the non-tail padding parts.
5099 Use __builtin_memcpy for the bitwise copy. */
5101 tree arg0, arg1, arg2, t;
5103 arg2 = TYPE_SIZE_UNIT (as_base);
5105 arg0 = build_unary_op (ADDR_EXPR, to, 0);
5106 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
5107 t = build_call_n (t, 3, arg0, arg1, arg2);
5109 t = convert (TREE_TYPE (arg0), t);
5110 val = build_indirect_ref (t, 0);
5118 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
5121 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
5124 gcc_assert (binfo && binfo != error_mark_node);
5126 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
5127 if (TREE_SIDE_EFFECTS (argarray[0]))
5128 argarray[0] = save_expr (argarray[0]);
5129 t = build_pointer_type (TREE_TYPE (fn));
5130 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5131 fn = build_java_interface_fn_ref (fn, argarray[0]);
5133 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
5136 else if (DECL_INLINE (fn))
5137 fn = inline_conversion (fn);
5139 fn = build_addr_func (fn);
5141 return build_cxx_call (fn, nargs, argarray);
5144 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5145 This function performs no overload resolution, conversion, or other
5146 high-level operations. */
5149 build_cxx_call (tree fn, int nargs, tree *argarray)
5153 fn = build_call_a (fn, nargs, argarray);
5155 /* If this call might throw an exception, note that fact. */
5156 fndecl = get_callee_fndecl (fn);
5157 if ((!fndecl || !TREE_NOTHROW (fndecl))
5158 && at_function_scope_p ()
5160 cp_function_chain->can_throw = 1;
5162 /* Some built-in function calls will be evaluated at compile-time in
5164 fn = fold_if_not_in_template (fn);
5166 if (VOID_TYPE_P (TREE_TYPE (fn)))
5169 fn = require_complete_type (fn);
5170 if (fn == error_mark_node)
5171 return error_mark_node;
5173 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
5174 fn = build_cplus_new (TREE_TYPE (fn), fn);
5175 return convert_from_reference (fn);
5178 static GTY(()) tree java_iface_lookup_fn;
5180 /* Make an expression which yields the address of the Java interface
5181 method FN. This is achieved by generating a call to libjava's
5182 _Jv_LookupInterfaceMethodIdx(). */
5185 build_java_interface_fn_ref (tree fn, tree instance)
5187 tree lookup_fn, method, idx;
5188 tree klass_ref, iface, iface_ref;
5191 if (!java_iface_lookup_fn)
5193 tree endlink = build_void_list_node ();
5194 tree t = tree_cons (NULL_TREE, ptr_type_node,
5195 tree_cons (NULL_TREE, ptr_type_node,
5196 tree_cons (NULL_TREE, java_int_type_node,
5198 java_iface_lookup_fn
5199 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx",
5200 build_function_type (ptr_type_node, t),
5201 0, NOT_BUILT_IN, NULL, NULL_TREE);
5204 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5205 This is the first entry in the vtable. */
5206 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
5209 /* Get the java.lang.Class pointer for the interface being called. */
5210 iface = DECL_CONTEXT (fn);
5211 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5212 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5213 || DECL_CONTEXT (iface_ref) != iface)
5215 error ("could not find class$ field in java interface type %qT",
5217 return error_mark_node;
5219 iface_ref = build_address (iface_ref);
5220 iface_ref = convert (build_pointer_type (iface), iface_ref);
5222 /* Determine the itable index of FN. */
5224 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5226 if (!DECL_VIRTUAL_P (method))
5232 idx = build_int_cst (NULL_TREE, i);
5234 lookup_fn = build1 (ADDR_EXPR,
5235 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5236 java_iface_lookup_fn);
5237 return build_call_nary (ptr_type_node, lookup_fn,
5238 3, klass_ref, iface_ref, idx);
5241 /* Returns the value to use for the in-charge parameter when making a
5242 call to a function with the indicated NAME.
5244 FIXME:Can't we find a neater way to do this mapping? */
5247 in_charge_arg_for_name (tree name)
5249 if (name == base_ctor_identifier
5250 || name == base_dtor_identifier)
5251 return integer_zero_node;
5252 else if (name == complete_ctor_identifier)
5253 return integer_one_node;
5254 else if (name == complete_dtor_identifier)
5255 return integer_two_node;
5256 else if (name == deleting_dtor_identifier)
5257 return integer_three_node;
5259 /* This function should only be called with one of the names listed
5265 /* Build a call to a constructor, destructor, or an assignment
5266 operator for INSTANCE, an expression with class type. NAME
5267 indicates the special member function to call; ARGS are the
5268 arguments. BINFO indicates the base of INSTANCE that is to be
5269 passed as the `this' parameter to the member function called.
5271 FLAGS are the LOOKUP_* flags to use when processing the call.
5273 If NAME indicates a complete object constructor, INSTANCE may be
5274 NULL_TREE. In this case, the caller will call build_cplus_new to
5275 store the newly constructed object into a VAR_DECL. */
5278 build_special_member_call (tree instance, tree name, tree args,
5279 tree binfo, int flags)
5282 /* The type of the subobject to be constructed or destroyed. */
5285 gcc_assert (name == complete_ctor_identifier
5286 || name == base_ctor_identifier
5287 || name == complete_dtor_identifier
5288 || name == base_dtor_identifier
5289 || name == deleting_dtor_identifier
5290 || name == ansi_assopname (NOP_EXPR));
5293 /* Resolve the name. */
5294 if (!complete_type_or_else (binfo, NULL_TREE))
5295 return error_mark_node;
5297 binfo = TYPE_BINFO (binfo);
5300 gcc_assert (binfo != NULL_TREE);
5302 class_type = BINFO_TYPE (binfo);
5304 /* Handle the special case where INSTANCE is NULL_TREE. */
5305 if (name == complete_ctor_identifier && !instance)
5307 instance = build_int_cst (build_pointer_type (class_type), 0);
5308 instance = build1 (INDIRECT_REF, class_type, instance);
5312 if (name == complete_dtor_identifier
5313 || name == base_dtor_identifier
5314 || name == deleting_dtor_identifier)
5315 gcc_assert (args == NULL_TREE);
5317 /* Convert to the base class, if necessary. */
5318 if (!same_type_ignoring_top_level_qualifiers_p
5319 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5321 if (name != ansi_assopname (NOP_EXPR))
5322 /* For constructors and destructors, either the base is
5323 non-virtual, or it is virtual but we are doing the
5324 conversion from a constructor or destructor for the
5325 complete object. In either case, we can convert
5327 instance = convert_to_base_statically (instance, binfo);
5329 /* However, for assignment operators, we must convert
5330 dynamically if the base is virtual. */
5331 instance = build_base_path (PLUS_EXPR, instance,
5332 binfo, /*nonnull=*/1);
5336 gcc_assert (instance != NULL_TREE);
5338 fns = lookup_fnfields (binfo, name, 1);
5340 /* When making a call to a constructor or destructor for a subobject
5341 that uses virtual base classes, pass down a pointer to a VTT for
5343 if ((name == base_ctor_identifier
5344 || name == base_dtor_identifier)
5345 && CLASSTYPE_VBASECLASSES (class_type))
5350 /* If the current function is a complete object constructor
5351 or destructor, then we fetch the VTT directly.
5352 Otherwise, we look it up using the VTT we were given. */
5353 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5354 vtt = decay_conversion (vtt);
5355 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5356 build2 (EQ_EXPR, boolean_type_node,
5357 current_in_charge_parm, integer_zero_node),
5360 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5361 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
5362 BINFO_SUBVTT_INDEX (binfo));
5364 args = tree_cons (NULL_TREE, sub_vtt, args);
5367 return build_new_method_call (instance, fns, args,
5368 TYPE_BINFO (BINFO_TYPE (binfo)),
5369 flags, /*fn=*/NULL);
5372 /* Return the NAME, as a C string. The NAME indicates a function that
5373 is a member of TYPE. *FREE_P is set to true if the caller must
5374 free the memory returned.
5376 Rather than go through all of this, we should simply set the names
5377 of constructors and destructors appropriately, and dispense with
5378 ctor_identifier, dtor_identifier, etc. */
5381 name_as_c_string (tree name, tree type, bool *free_p)
5385 /* Assume that we will not allocate memory. */
5387 /* Constructors and destructors are special. */
5388 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5391 = CONST_CAST (char *, IDENTIFIER_POINTER (constructor_name (type)));
5392 /* For a destructor, add the '~'. */
5393 if (name == complete_dtor_identifier
5394 || name == base_dtor_identifier
5395 || name == deleting_dtor_identifier)
5397 pretty_name = concat ("~", pretty_name, NULL);
5398 /* Remember that we need to free the memory allocated. */
5402 else if (IDENTIFIER_TYPENAME_P (name))
5404 pretty_name = concat ("operator ",
5405 type_as_string (TREE_TYPE (name),
5406 TFF_PLAIN_IDENTIFIER),
5408 /* Remember that we need to free the memory allocated. */
5412 pretty_name = CONST_CAST (char *, IDENTIFIER_POINTER (name));
5417 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5418 be set, upon return, to the function called. */
5421 build_new_method_call (tree instance, tree fns, tree args,
5422 tree conversion_path, int flags,
5425 struct z_candidate *candidates = 0, *cand;
5426 tree explicit_targs = NULL_TREE;
5427 tree basetype = NULL_TREE;
5430 tree mem_args = NULL_TREE, instance_ptr;
5436 int template_only = 0;
5443 gcc_assert (instance != NULL_TREE);
5445 /* We don't know what function we're going to call, yet. */
5449 if (error_operand_p (instance)
5450 || error_operand_p (fns)
5451 || args == error_mark_node)
5452 return error_mark_node;
5454 if (!BASELINK_P (fns))
5456 error ("call to non-function %qD", fns);
5457 return error_mark_node;
5460 orig_instance = instance;
5464 /* Dismantle the baselink to collect all the information we need. */
5465 if (!conversion_path)
5466 conversion_path = BASELINK_BINFO (fns);
5467 access_binfo = BASELINK_ACCESS_BINFO (fns);
5468 optype = BASELINK_OPTYPE (fns);
5469 fns = BASELINK_FUNCTIONS (fns);
5470 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5472 explicit_targs = TREE_OPERAND (fns, 1);
5473 fns = TREE_OPERAND (fns, 0);
5476 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5477 || TREE_CODE (fns) == TEMPLATE_DECL
5478 || TREE_CODE (fns) == OVERLOAD);
5479 fn = get_first_fn (fns);
5480 name = DECL_NAME (fn);
5482 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5483 gcc_assert (CLASS_TYPE_P (basetype));
5485 if (processing_template_decl)
5487 instance = build_non_dependent_expr (instance);
5488 args = build_non_dependent_args (orig_args);
5491 /* The USER_ARGS are the arguments we will display to users if an
5492 error occurs. The USER_ARGS should not include any
5493 compiler-generated arguments. The "this" pointer hasn't been
5494 added yet. However, we must remove the VTT pointer if this is a
5495 call to a base-class constructor or destructor. */
5497 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5499 /* Callers should explicitly indicate whether they want to construct
5500 the complete object or just the part without virtual bases. */
5501 gcc_assert (name != ctor_identifier);
5502 /* Similarly for destructors. */
5503 gcc_assert (name != dtor_identifier);
5504 /* Remove the VTT pointer, if present. */
5505 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5506 && CLASSTYPE_VBASECLASSES (basetype))
5507 user_args = TREE_CHAIN (user_args);
5510 /* Process the argument list. */
5511 args = resolve_args (args);
5512 if (args == error_mark_node)
5513 return error_mark_node;
5515 instance_ptr = build_this (instance);
5517 /* It's OK to call destructors and constructors on cv-qualified objects.
5518 Therefore, convert the INSTANCE_PTR to the unqualified type, if
5520 if (DECL_DESTRUCTOR_P (fn)
5521 || DECL_CONSTRUCTOR_P (fn))
5523 tree type = build_pointer_type (basetype);
5524 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5525 instance_ptr = build_nop (type, instance_ptr);
5527 if (DECL_DESTRUCTOR_P (fn))
5528 name = complete_dtor_identifier;
5530 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5531 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5533 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5534 p = conversion_obstack_alloc (0);
5536 for (fn = fns; fn; fn = OVL_NEXT (fn))
5538 tree t = OVL_CURRENT (fn);
5541 /* We can end up here for copy-init of same or base class. */
5542 if ((flags & LOOKUP_ONLYCONVERTING)
5543 && DECL_NONCONVERTING_P (t))
5546 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5547 this_arglist = mem_args;
5549 this_arglist = args;
5551 if (TREE_CODE (t) == TEMPLATE_DECL)
5552 /* A member template. */
5553 add_template_candidate (&candidates, t,
5556 this_arglist, optype,
5561 else if (! template_only)
5562 add_function_candidate (&candidates, t,
5570 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5573 if (!COMPLETE_TYPE_P (basetype))
5574 cxx_incomplete_type_error (instance_ptr, basetype);
5580 pretty_name = name_as_c_string (name, basetype, &free_p);
5581 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5582 basetype, pretty_name, user_args,
5583 TREE_TYPE (TREE_TYPE (instance_ptr)));
5587 print_z_candidates (candidates);
5588 call = error_mark_node;
5592 cand = tourney (candidates);
5598 pretty_name = name_as_c_string (name, basetype, &free_p);
5599 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5601 print_z_candidates (candidates);
5604 call = error_mark_node;
5610 if (!(flags & LOOKUP_NONVIRTUAL)
5611 && DECL_PURE_VIRTUAL_P (fn)
5612 && instance == current_class_ref
5613 && (DECL_CONSTRUCTOR_P (current_function_decl)
5614 || DECL_DESTRUCTOR_P (current_function_decl)))
5615 /* This is not an error, it is runtime undefined
5617 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
5618 "abstract virtual %q#D called from constructor"
5619 : "abstract virtual %q#D called from destructor"),
5622 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
5623 && is_dummy_object (instance_ptr))
5625 error ("cannot call member function %qD without object",
5627 call = error_mark_node;
5631 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
5632 && resolves_to_fixed_type_p (instance, 0))
5633 flags |= LOOKUP_NONVIRTUAL;
5634 /* Now we know what function is being called. */
5637 /* Build the actual CALL_EXPR. */
5638 call = build_over_call (cand, flags);
5639 /* In an expression of the form `a->f()' where `f' turns
5640 out to be a static member function, `a' is
5641 none-the-less evaluated. */
5642 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
5643 && !is_dummy_object (instance_ptr)
5644 && TREE_SIDE_EFFECTS (instance_ptr))
5645 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5646 instance_ptr, call);
5647 else if (call != error_mark_node
5648 && DECL_DESTRUCTOR_P (cand->fn)
5649 && !VOID_TYPE_P (TREE_TYPE (call)))
5650 /* An explicit call of the form "x->~X()" has type
5651 "void". However, on platforms where destructors
5652 return "this" (i.e., those where
5653 targetm.cxx.cdtor_returns_this is true), such calls
5654 will appear to have a return value of pointer type
5655 to the low-level call machinery. We do not want to
5656 change the low-level machinery, since we want to be
5657 able to optimize "delete f()" on such platforms as
5658 "operator delete(~X(f()))" (rather than generating
5659 "t = f(), ~X(t), operator delete (t)"). */
5660 call = build_nop (void_type_node, call);
5665 if (processing_template_decl && call != error_mark_node)
5666 call = (build_min_non_dep_call_list
5668 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5671 /* Free all the conversions we allocated. */
5672 obstack_free (&conversion_obstack, p);
5677 /* Returns true iff standard conversion sequence ICS1 is a proper
5678 subsequence of ICS2. */
5681 is_subseq (conversion *ics1, conversion *ics2)
5683 /* We can assume that a conversion of the same code
5684 between the same types indicates a subsequence since we only get
5685 here if the types we are converting from are the same. */
5687 while (ics1->kind == ck_rvalue
5688 || ics1->kind == ck_lvalue)
5689 ics1 = ics1->u.next;
5693 while (ics2->kind == ck_rvalue
5694 || ics2->kind == ck_lvalue)
5695 ics2 = ics2->u.next;
5697 if (ics2->kind == ck_user
5698 || ics2->kind == ck_ambig
5699 || ics2->kind == ck_identity)
5700 /* At this point, ICS1 cannot be a proper subsequence of
5701 ICS2. We can get a USER_CONV when we are comparing the
5702 second standard conversion sequence of two user conversion
5706 ics2 = ics2->u.next;
5708 if (ics2->kind == ics1->kind
5709 && same_type_p (ics2->type, ics1->type)
5710 && same_type_p (ics2->u.next->type,
5711 ics1->u.next->type))
5716 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5717 be any _TYPE nodes. */
5720 is_properly_derived_from (tree derived, tree base)
5722 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5723 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5726 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5727 considers every class derived from itself. */
5728 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5729 && DERIVED_FROM_P (base, derived));
5732 /* We build the ICS for an implicit object parameter as a pointer
5733 conversion sequence. However, such a sequence should be compared
5734 as if it were a reference conversion sequence. If ICS is the
5735 implicit conversion sequence for an implicit object parameter,
5736 modify it accordingly. */
5739 maybe_handle_implicit_object (conversion **ics)
5743 /* [over.match.funcs]
5745 For non-static member functions, the type of the
5746 implicit object parameter is "reference to cv X"
5747 where X is the class of which the function is a
5748 member and cv is the cv-qualification on the member
5749 function declaration. */
5750 conversion *t = *ics;
5751 tree reference_type;
5753 /* The `this' parameter is a pointer to a class type. Make the
5754 implicit conversion talk about a reference to that same class
5756 reference_type = TREE_TYPE (t->type);
5757 reference_type = build_reference_type (reference_type);
5759 if (t->kind == ck_qual)
5761 if (t->kind == ck_ptr)
5763 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5764 t = direct_reference_binding (reference_type, t);
5765 t->rvaluedness_matches_p = 1;
5770 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5771 and return the initial reference binding conversion. Otherwise,
5772 leave *ICS unchanged and return NULL. */
5775 maybe_handle_ref_bind (conversion **ics)
5777 if ((*ics)->kind == ck_ref_bind)
5779 conversion *old_ics = *ics;
5780 *ics = old_ics->u.next;
5781 (*ics)->user_conv_p = old_ics->user_conv_p;
5782 (*ics)->bad_p = old_ics->bad_p;
5789 /* Compare two implicit conversion sequences according to the rules set out in
5790 [over.ics.rank]. Return values:
5792 1: ics1 is better than ics2
5793 -1: ics2 is better than ics1
5794 0: ics1 and ics2 are indistinguishable */
5797 compare_ics (conversion *ics1, conversion *ics2)
5803 tree deref_from_type1 = NULL_TREE;
5804 tree deref_from_type2 = NULL_TREE;
5805 tree deref_to_type1 = NULL_TREE;
5806 tree deref_to_type2 = NULL_TREE;
5807 conversion_rank rank1, rank2;
5809 /* REF_BINDING is nonzero if the result of the conversion sequence
5810 is a reference type. In that case REF_CONV is the reference
5811 binding conversion. */
5812 conversion *ref_conv1;
5813 conversion *ref_conv2;
5815 /* Handle implicit object parameters. */
5816 maybe_handle_implicit_object (&ics1);
5817 maybe_handle_implicit_object (&ics2);
5819 /* Handle reference parameters. */
5820 ref_conv1 = maybe_handle_ref_bind (&ics1);
5821 ref_conv2 = maybe_handle_ref_bind (&ics2);
5825 When comparing the basic forms of implicit conversion sequences (as
5826 defined in _over.best.ics_)
5828 --a standard conversion sequence (_over.ics.scs_) is a better
5829 conversion sequence than a user-defined conversion sequence
5830 or an ellipsis conversion sequence, and
5832 --a user-defined conversion sequence (_over.ics.user_) is a
5833 better conversion sequence than an ellipsis conversion sequence
5834 (_over.ics.ellipsis_). */
5835 rank1 = CONVERSION_RANK (ics1);
5836 rank2 = CONVERSION_RANK (ics2);
5840 else if (rank1 < rank2)
5843 if (rank1 == cr_bad)
5845 /* XXX Isn't this an extension? */
5846 /* Both ICS are bad. We try to make a decision based on what
5847 would have happened if they'd been good. */
5848 if (ics1->user_conv_p > ics2->user_conv_p
5849 || ics1->rank > ics2->rank)
5851 else if (ics1->user_conv_p < ics2->user_conv_p
5852 || ics1->rank < ics2->rank)
5855 /* We couldn't make up our minds; try to figure it out below. */
5858 if (ics1->ellipsis_p)
5859 /* Both conversions are ellipsis conversions. */
5862 /* User-defined conversion sequence U1 is a better conversion sequence
5863 than another user-defined conversion sequence U2 if they contain the
5864 same user-defined conversion operator or constructor and if the sec-
5865 ond standard conversion sequence of U1 is better than the second
5866 standard conversion sequence of U2. */
5868 if (ics1->user_conv_p)
5873 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5874 if (t1->kind == ck_ambig)
5876 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5877 if (t2->kind == ck_ambig)
5880 if (t1->cand->fn != t2->cand->fn)
5883 /* We can just fall through here, after setting up
5884 FROM_TYPE1 and FROM_TYPE2. */
5885 from_type1 = t1->type;
5886 from_type2 = t2->type;
5893 /* We're dealing with two standard conversion sequences.
5897 Standard conversion sequence S1 is a better conversion
5898 sequence than standard conversion sequence S2 if
5900 --S1 is a proper subsequence of S2 (comparing the conversion
5901 sequences in the canonical form defined by _over.ics.scs_,
5902 excluding any Lvalue Transformation; the identity
5903 conversion sequence is considered to be a subsequence of
5904 any non-identity conversion sequence */
5907 while (t1->kind != ck_identity)
5909 from_type1 = t1->type;
5912 while (t2->kind != ck_identity)
5914 from_type2 = t2->type;
5917 if (same_type_p (from_type1, from_type2))
5919 if (is_subseq (ics1, ics2))
5921 if (is_subseq (ics2, ics1))
5924 /* Otherwise, one sequence cannot be a subsequence of the other; they
5925 don't start with the same type. This can happen when comparing the
5926 second standard conversion sequence in two user-defined conversion
5933 --the rank of S1 is better than the rank of S2 (by the rules
5936 Standard conversion sequences are ordered by their ranks: an Exact
5937 Match is a better conversion than a Promotion, which is a better
5938 conversion than a Conversion.
5940 Two conversion sequences with the same rank are indistinguishable
5941 unless one of the following rules applies:
5943 --A conversion that is not a conversion of a pointer, or pointer
5944 to member, to bool is better than another conversion that is such
5947 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5948 so that we do not have to check it explicitly. */
5949 if (ics1->rank < ics2->rank)
5951 else if (ics2->rank < ics1->rank)
5954 to_type1 = ics1->type;
5955 to_type2 = ics2->type;
5957 if (TYPE_PTR_P (from_type1)
5958 && TYPE_PTR_P (from_type2)
5959 && TYPE_PTR_P (to_type1)
5960 && TYPE_PTR_P (to_type2))
5962 deref_from_type1 = TREE_TYPE (from_type1);
5963 deref_from_type2 = TREE_TYPE (from_type2);
5964 deref_to_type1 = TREE_TYPE (to_type1);
5965 deref_to_type2 = TREE_TYPE (to_type2);
5967 /* The rules for pointers to members A::* are just like the rules
5968 for pointers A*, except opposite: if B is derived from A then
5969 A::* converts to B::*, not vice versa. For that reason, we
5970 switch the from_ and to_ variables here. */
5971 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5972 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5973 || (TYPE_PTRMEMFUNC_P (from_type1)
5974 && TYPE_PTRMEMFUNC_P (from_type2)
5975 && TYPE_PTRMEMFUNC_P (to_type1)
5976 && TYPE_PTRMEMFUNC_P (to_type2)))
5978 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5979 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5980 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5981 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5984 if (deref_from_type1 != NULL_TREE
5985 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5986 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5988 /* This was one of the pointer or pointer-like conversions.
5992 --If class B is derived directly or indirectly from class A,
5993 conversion of B* to A* is better than conversion of B* to
5994 void*, and conversion of A* to void* is better than
5995 conversion of B* to void*. */
5996 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5997 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5999 if (is_properly_derived_from (deref_from_type1,
6002 else if (is_properly_derived_from (deref_from_type2,
6006 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
6007 || TREE_CODE (deref_to_type2) == VOID_TYPE)
6009 if (same_type_p (deref_from_type1, deref_from_type2))
6011 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
6013 if (is_properly_derived_from (deref_from_type1,
6017 /* We know that DEREF_TO_TYPE1 is `void' here. */
6018 else if (is_properly_derived_from (deref_from_type1,
6023 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
6024 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
6028 --If class B is derived directly or indirectly from class A
6029 and class C is derived directly or indirectly from B,
6031 --conversion of C* to B* is better than conversion of C* to
6034 --conversion of B* to A* is better than conversion of C* to
6036 if (same_type_p (deref_from_type1, deref_from_type2))
6038 if (is_properly_derived_from (deref_to_type1,
6041 else if (is_properly_derived_from (deref_to_type2,
6045 else if (same_type_p (deref_to_type1, deref_to_type2))
6047 if (is_properly_derived_from (deref_from_type2,
6050 else if (is_properly_derived_from (deref_from_type1,
6056 else if (CLASS_TYPE_P (non_reference (from_type1))
6057 && same_type_p (from_type1, from_type2))
6059 tree from = non_reference (from_type1);
6063 --binding of an expression of type C to a reference of type
6064 B& is better than binding an expression of type C to a
6065 reference of type A&
6067 --conversion of C to B is better than conversion of C to A, */
6068 if (is_properly_derived_from (from, to_type1)
6069 && is_properly_derived_from (from, to_type2))
6071 if (is_properly_derived_from (to_type1, to_type2))
6073 else if (is_properly_derived_from (to_type2, to_type1))
6077 else if (CLASS_TYPE_P (non_reference (to_type1))
6078 && same_type_p (to_type1, to_type2))
6080 tree to = non_reference (to_type1);
6084 --binding of an expression of type B to a reference of type
6085 A& is better than binding an expression of type C to a
6086 reference of type A&,
6088 --conversion of B to A is better than conversion of C to A */
6089 if (is_properly_derived_from (from_type1, to)
6090 && is_properly_derived_from (from_type2, to))
6092 if (is_properly_derived_from (from_type2, from_type1))
6094 else if (is_properly_derived_from (from_type1, from_type2))
6101 --S1 and S2 differ only in their qualification conversion and yield
6102 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6103 qualification signature of type T1 is a proper subset of the cv-
6104 qualification signature of type T2 */
6105 if (ics1->kind == ck_qual
6106 && ics2->kind == ck_qual
6107 && same_type_p (from_type1, from_type2))
6108 return comp_cv_qual_signature (to_type1, to_type2);
6112 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
6113 to an implicit object parameter, and either S1 binds an lvalue reference
6114 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
6115 reference to an rvalue and S2 binds an lvalue reference
6116 (C++0x draft standard, 13.3.3.2)
6118 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6119 types to which the references refer are the same type except for
6120 top-level cv-qualifiers, and the type to which the reference
6121 initialized by S2 refers is more cv-qualified than the type to
6122 which the reference initialized by S1 refers */
6124 if (ref_conv1 && ref_conv2
6125 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
6127 if (ref_conv1->rvaluedness_matches_p
6128 && !ref_conv2->rvaluedness_matches_p)
6130 else if (!ref_conv1->rvaluedness_matches_p
6131 && ref_conv2->rvaluedness_matches_p)
6134 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
6135 TREE_TYPE (ref_conv1->type));
6138 /* Neither conversion sequence is better than the other. */
6142 /* The source type for this standard conversion sequence. */
6145 source_type (conversion *t)
6147 for (;; t = t->u.next)
6149 if (t->kind == ck_user
6150 || t->kind == ck_ambig
6151 || t->kind == ck_identity)
6157 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6158 a pointer to LOSER and re-running joust to produce the warning if WINNER
6159 is actually used. */
6162 add_warning (struct z_candidate *winner, struct z_candidate *loser)
6164 candidate_warning *cw = (candidate_warning *)
6165 conversion_obstack_alloc (sizeof (candidate_warning));
6167 cw->next = winner->warnings;
6168 winner->warnings = cw;
6171 /* Compare two candidates for overloading as described in
6172 [over.match.best]. Return values:
6174 1: cand1 is better than cand2
6175 -1: cand2 is better than cand1
6176 0: cand1 and cand2 are indistinguishable */
6179 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
6182 int off1 = 0, off2 = 0;
6186 /* Candidates that involve bad conversions are always worse than those
6188 if (cand1->viable > cand2->viable)
6190 if (cand1->viable < cand2->viable)
6193 /* If we have two pseudo-candidates for conversions to the same type,
6194 or two candidates for the same function, arbitrarily pick one. */
6195 if (cand1->fn == cand2->fn
6196 && (IS_TYPE_OR_DECL_P (cand1->fn)))
6199 /* a viable function F1
6200 is defined to be a better function than another viable function F2 if
6201 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6202 ICSi(F2), and then */
6204 /* for some argument j, ICSj(F1) is a better conversion sequence than
6207 /* For comparing static and non-static member functions, we ignore
6208 the implicit object parameter of the non-static function. The
6209 standard says to pretend that the static function has an object
6210 parm, but that won't work with operator overloading. */
6211 len = cand1->num_convs;
6212 if (len != cand2->num_convs)
6214 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
6215 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
6217 gcc_assert (static_1 != static_2);
6228 for (i = 0; i < len; ++i)
6230 conversion *t1 = cand1->convs[i + off1];
6231 conversion *t2 = cand2->convs[i + off2];
6232 int comp = compare_ics (t1, t2);
6237 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
6238 == cr_std + cr_promotion)
6239 && t1->kind == ck_std
6240 && t2->kind == ck_std
6241 && TREE_CODE (t1->type) == INTEGER_TYPE
6242 && TREE_CODE (t2->type) == INTEGER_TYPE
6243 && (TYPE_PRECISION (t1->type)
6244 == TYPE_PRECISION (t2->type))
6245 && (TYPE_UNSIGNED (t1->u.next->type)
6246 || (TREE_CODE (t1->u.next->type)
6249 tree type = t1->u.next->type;
6251 struct z_candidate *w, *l;
6253 type1 = t1->type, type2 = t2->type,
6254 w = cand1, l = cand2;
6256 type1 = t2->type, type2 = t1->type,
6257 w = cand2, l = cand1;
6261 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
6262 type, type1, type2);
6263 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
6269 if (winner && comp != winner)
6278 /* warn about confusing overload resolution for user-defined conversions,
6279 either between a constructor and a conversion op, or between two
6281 if (winner && warn_conversion && cand1->second_conv
6282 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
6283 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
6285 struct z_candidate *w, *l;
6286 bool give_warning = false;
6289 w = cand1, l = cand2;
6291 w = cand2, l = cand1;
6293 /* We don't want to complain about `X::operator T1 ()'
6294 beating `X::operator T2 () const', when T2 is a no less
6295 cv-qualified version of T1. */
6296 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
6297 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
6299 tree t = TREE_TYPE (TREE_TYPE (l->fn));
6300 tree f = TREE_TYPE (TREE_TYPE (w->fn));
6302 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6307 if (!comp_ptr_ttypes (t, f))
6308 give_warning = true;
6311 give_warning = true;
6317 tree source = source_type (w->convs[0]);
6318 if (! DECL_CONSTRUCTOR_P (w->fn))
6319 source = TREE_TYPE (source);
6320 warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn);
6321 warning (OPT_Wconversion, " for conversion from %qT to %qT",
6322 source, w->second_conv->type);
6323 inform (" because conversion sequence for the argument is better");
6333 F1 is a non-template function and F2 is a template function
6336 if (!cand1->template_decl && cand2->template_decl)
6338 else if (cand1->template_decl && !cand2->template_decl)
6342 F1 and F2 are template functions and the function template for F1 is
6343 more specialized than the template for F2 according to the partial
6346 if (cand1->template_decl && cand2->template_decl)
6348 winner = more_specialized_fn
6349 (TI_TEMPLATE (cand1->template_decl),
6350 TI_TEMPLATE (cand2->template_decl),
6351 /* [temp.func.order]: The presence of unused ellipsis and default
6352 arguments has no effect on the partial ordering of function
6353 templates. add_function_candidate() will not have
6354 counted the "this" argument for constructors. */
6355 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
6361 the context is an initialization by user-defined conversion (see
6362 _dcl.init_ and _over.match.user_) and the standard conversion
6363 sequence from the return type of F1 to the destination type (i.e.,
6364 the type of the entity being initialized) is a better conversion
6365 sequence than the standard conversion sequence from the return type
6366 of F2 to the destination type. */
6368 if (cand1->second_conv)
6370 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6375 /* Check whether we can discard a builtin candidate, either because we
6376 have two identical ones or matching builtin and non-builtin candidates.
6378 (Pedantically in the latter case the builtin which matched the user
6379 function should not be added to the overload set, but we spot it here.
6382 ... the builtin candidates include ...
6383 - do not have the same parameter type list as any non-template
6384 non-member candidate. */
6386 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6387 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6389 for (i = 0; i < len; ++i)
6390 if (!same_type_p (cand1->convs[i]->type,
6391 cand2->convs[i]->type))
6393 if (i == cand1->num_convs)
6395 if (cand1->fn == cand2->fn)
6396 /* Two built-in candidates; arbitrarily pick one. */
6398 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6399 /* cand1 is built-in; prefer cand2. */
6402 /* cand2 is built-in; prefer cand1. */
6407 /* If the two functions are the same (this can happen with declarations
6408 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6409 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6410 && equal_functions (cand1->fn, cand2->fn))
6415 /* Extension: If the worst conversion for one candidate is worse than the
6416 worst conversion for the other, take the first. */
6419 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6420 struct z_candidate *w = 0, *l = 0;
6422 for (i = 0; i < len; ++i)
6424 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6425 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6426 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6427 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6430 winner = 1, w = cand1, l = cand2;
6432 winner = -1, w = cand2, l = cand1;
6438 ISO C++ says that these are ambiguous, even \
6439 though the worst conversion for the first is better than \
6440 the worst conversion for the second:");
6441 print_z_candidate (_("candidate 1:"), w);
6442 print_z_candidate (_("candidate 2:"), l);
6450 gcc_assert (!winner);
6454 /* Given a list of candidates for overloading, find the best one, if any.
6455 This algorithm has a worst case of O(2n) (winner is last), and a best
6456 case of O(n/2) (totally ambiguous); much better than a sorting
6459 static struct z_candidate *
6460 tourney (struct z_candidate *candidates)
6462 struct z_candidate *champ = candidates, *challenger;
6464 int champ_compared_to_predecessor = 0;
6466 /* Walk through the list once, comparing each current champ to the next
6467 candidate, knocking out a candidate or two with each comparison. */
6469 for (challenger = champ->next; challenger; )
6471 fate = joust (champ, challenger, 0);
6473 challenger = challenger->next;
6478 champ = challenger->next;
6481 champ_compared_to_predecessor = 0;
6486 champ_compared_to_predecessor = 1;
6489 challenger = champ->next;
6493 /* Make sure the champ is better than all the candidates it hasn't yet
6494 been compared to. */
6496 for (challenger = candidates;
6498 && !(champ_compared_to_predecessor && challenger->next == champ);
6499 challenger = challenger->next)
6501 fate = joust (champ, challenger, 0);
6509 /* Returns nonzero if things of type FROM can be converted to TO. */
6512 can_convert (tree to, tree from)
6514 return can_convert_arg (to, from, NULL_TREE, LOOKUP_NORMAL);
6517 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6520 can_convert_arg (tree to, tree from, tree arg, int flags)
6526 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6527 p = conversion_obstack_alloc (0);
6529 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6531 ok_p = (t && !t->bad_p);
6533 /* Free all the conversions we allocated. */
6534 obstack_free (&conversion_obstack, p);
6539 /* Like can_convert_arg, but allows dubious conversions as well. */
6542 can_convert_arg_bad (tree to, tree from, tree arg)
6547 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6548 p = conversion_obstack_alloc (0);
6549 /* Try to perform the conversion. */
6550 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6552 /* Free all the conversions we allocated. */
6553 obstack_free (&conversion_obstack, p);
6558 /* Convert EXPR to TYPE. Return the converted expression.
6560 Note that we allow bad conversions here because by the time we get to
6561 this point we are committed to doing the conversion. If we end up
6562 doing a bad conversion, convert_like will complain. */
6565 perform_implicit_conversion (tree type, tree expr)
6570 if (error_operand_p (expr))
6571 return error_mark_node;
6573 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6574 p = conversion_obstack_alloc (0);
6576 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6581 error ("could not convert %qE to %qT", expr, type);
6582 expr = error_mark_node;
6584 else if (processing_template_decl)
6586 /* In a template, we are only concerned about determining the
6587 type of non-dependent expressions, so we do not have to
6588 perform the actual conversion. */
6589 if (TREE_TYPE (expr) != type)
6590 expr = build_nop (type, expr);
6593 expr = convert_like (conv, expr);
6595 /* Free all the conversions we allocated. */
6596 obstack_free (&conversion_obstack, p);
6601 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6602 permitted. If the conversion is valid, the converted expression is
6603 returned. Otherwise, NULL_TREE is returned, except in the case
6604 that TYPE is a class type; in that case, an error is issued. If
6605 C_CAST_P is true, then this direction initialization is taking
6606 place as part of a static_cast being attempted as part of a C-style
6610 perform_direct_initialization_if_possible (tree type,
6617 if (type == error_mark_node || error_operand_p (expr))
6618 return error_mark_node;
6621 If the destination type is a (possibly cv-qualified) class type:
6623 -- If the initialization is direct-initialization ...,
6624 constructors are considered. ... If no constructor applies, or
6625 the overload resolution is ambiguous, the initialization is
6627 if (CLASS_TYPE_P (type))
6629 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6630 build_tree_list (NULL_TREE, expr),
6631 type, LOOKUP_NORMAL);
6632 return build_cplus_new (type, expr);
6635 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6636 p = conversion_obstack_alloc (0);
6638 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6641 if (!conv || conv->bad_p)
6644 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6645 /*issue_conversion_warnings=*/false,
6648 /* Free all the conversions we allocated. */
6649 obstack_free (&conversion_obstack, p);
6654 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6655 is being bound to a temporary. Create and return a new VAR_DECL
6656 with the indicated TYPE; this variable will store the value to
6657 which the reference is bound. */
6660 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6664 /* Create the variable. */
6665 var = create_temporary_var (type);
6667 /* Register the variable. */
6668 if (TREE_STATIC (decl))
6670 /* Namespace-scope or local static; give it a mangled name. */
6673 TREE_STATIC (var) = 1;
6674 name = mangle_ref_init_variable (decl);
6675 DECL_NAME (var) = name;
6676 SET_DECL_ASSEMBLER_NAME (var, name);
6677 var = pushdecl_top_level (var);
6680 /* Create a new cleanup level if necessary. */
6681 maybe_push_cleanup_level (type);
6686 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6687 initializing a variable of that TYPE. If DECL is non-NULL, it is
6688 the VAR_DECL being initialized with the EXPR. (In that case, the
6689 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6690 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6691 return, if *CLEANUP is no longer NULL, it will be an expression
6692 that should be pushed as a cleanup after the returned expression
6693 is used to initialize DECL.
6695 Return the converted expression. */
6698 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6703 if (type == error_mark_node || error_operand_p (expr))
6704 return error_mark_node;
6706 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6707 p = conversion_obstack_alloc (0);
6709 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
6711 if (!conv || conv->bad_p)
6713 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6714 && !real_lvalue_p (expr))
6715 error ("invalid initialization of non-const reference of "
6716 "type %qT from a temporary of type %qT",
6717 type, TREE_TYPE (expr));
6719 error ("invalid initialization of reference of type "
6720 "%qT from expression of type %qT", type,
6722 return error_mark_node;
6725 /* If DECL is non-NULL, then this special rule applies:
6729 The temporary to which the reference is bound or the temporary
6730 that is the complete object to which the reference is bound
6731 persists for the lifetime of the reference.
6733 The temporaries created during the evaluation of the expression
6734 initializing the reference, except the temporary to which the
6735 reference is bound, are destroyed at the end of the
6736 full-expression in which they are created.
6738 In that case, we store the converted expression into a new
6739 VAR_DECL in a new scope.
6741 However, we want to be careful not to create temporaries when
6742 they are not required. For example, given:
6745 struct D : public B {};
6749 there is no need to copy the return value from "f"; we can just
6750 extend its lifetime. Similarly, given:
6753 struct T { operator S(); };
6757 we can extend the lifetime of the return value of the conversion
6759 gcc_assert (conv->kind == ck_ref_bind);
6763 tree base_conv_type;
6765 /* Skip over the REF_BIND. */
6766 conv = conv->u.next;
6767 /* If the next conversion is a BASE_CONV, skip that too -- but
6768 remember that the conversion was required. */
6769 if (conv->kind == ck_base)
6771 if (conv->check_copy_constructor_p)
6772 check_constructor_callable (TREE_TYPE (expr), expr);
6773 base_conv_type = conv->type;
6774 conv = conv->u.next;
6777 base_conv_type = NULL_TREE;
6778 /* Perform the remainder of the conversion. */
6779 expr = convert_like_real (conv, expr,
6780 /*fn=*/NULL_TREE, /*argnum=*/0,
6782 /*issue_conversion_warnings=*/true,
6783 /*c_cast_p=*/false);
6784 if (error_operand_p (expr))
6785 expr = error_mark_node;
6788 if (!real_lvalue_p (expr))
6793 /* Create the temporary variable. */
6794 type = TREE_TYPE (expr);
6795 var = make_temporary_var_for_ref_to_temp (decl, type);
6796 layout_decl (var, 0);
6797 /* If the rvalue is the result of a function call it will be
6798 a TARGET_EXPR. If it is some other construct (such as a
6799 member access expression where the underlying object is
6800 itself the result of a function call), turn it into a
6801 TARGET_EXPR here. It is important that EXPR be a
6802 TARGET_EXPR below since otherwise the INIT_EXPR will
6803 attempt to make a bitwise copy of EXPR to initialize
6805 if (TREE_CODE (expr) != TARGET_EXPR)
6806 expr = get_target_expr (expr);
6807 /* Create the INIT_EXPR that will initialize the temporary
6809 init = build2 (INIT_EXPR, type, var, expr);
6810 if (at_function_scope_p ())
6812 add_decl_expr (var);
6813 *cleanup = cxx_maybe_build_cleanup (var);
6815 /* We must be careful to destroy the temporary only
6816 after its initialization has taken place. If the
6817 initialization throws an exception, then the
6818 destructor should not be run. We cannot simply
6819 transform INIT into something like:
6821 (INIT, ({ CLEANUP_STMT; }))
6823 because emit_local_var always treats the
6824 initializer as a full-expression. Thus, the
6825 destructor would run too early; it would run at the
6826 end of initializing the reference variable, rather
6827 than at the end of the block enclosing the
6830 The solution is to pass back a cleanup expression
6831 which the caller is responsible for attaching to
6832 the statement tree. */
6836 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6837 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6838 static_aggregates = tree_cons (NULL_TREE, var,
6841 /* Use its address to initialize the reference variable. */
6842 expr = build_address (var);
6844 expr = convert_to_base (expr,
6845 build_pointer_type (base_conv_type),
6846 /*check_access=*/true,
6848 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6851 /* Take the address of EXPR. */
6852 expr = build_unary_op (ADDR_EXPR, expr, 0);
6853 /* If a BASE_CONV was required, perform it now. */
6855 expr = (perform_implicit_conversion
6856 (build_pointer_type (base_conv_type), expr));
6857 expr = build_nop (type, expr);
6861 /* Perform the conversion. */
6862 expr = convert_like (conv, expr);
6864 /* Free all the conversions we allocated. */
6865 obstack_free (&conversion_obstack, p);
6870 #include "gt-cp-call.h"