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 2, 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 COPYING. If not, write to
22 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
23 Boston, MA 02110-1301, USA. */
26 /* High-level class interface. */
30 #include "coretypes.h"
39 #include "diagnostic.h"
43 #include "langhooks.h"
45 /* The various kinds of conversion. */
47 typedef enum conversion_kind {
61 /* The rank of the conversion. Order of the enumerals matters; better
62 conversions should come earlier in the list. */
64 typedef enum conversion_rank {
75 /* An implicit conversion sequence, in the sense of [over.best.ics].
76 The first conversion to be performed is at the end of the chain.
77 That conversion is always a cr_identity conversion. */
79 typedef struct conversion conversion;
81 /* The kind of conversion represented by this step. */
83 /* The rank of this conversion. */
85 BOOL_BITFIELD user_conv_p : 1;
86 BOOL_BITFIELD ellipsis_p : 1;
87 BOOL_BITFIELD this_p : 1;
88 BOOL_BITFIELD bad_p : 1;
89 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
90 temporary should be created to hold the result of the
92 BOOL_BITFIELD need_temporary_p : 1;
93 /* If KIND is ck_identity or ck_base_conv, true to indicate that the
94 copy constructor must be accessible, even though it is not being
96 BOOL_BITFIELD check_copy_constructor_p : 1;
97 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
98 from a pointer-to-derived to pointer-to-base is being performed. */
99 BOOL_BITFIELD base_p : 1;
100 /* The type of the expression resulting from the conversion. */
103 /* The next conversion in the chain. Since the conversions are
104 arranged from outermost to innermost, the NEXT conversion will
105 actually be performed before this conversion. This variant is
106 used only when KIND is neither ck_identity nor ck_ambig. */
108 /* The expression at the beginning of the conversion chain. This
109 variant is used only if KIND is ck_identity or ck_ambig. */
112 /* The function candidate corresponding to this conversion
113 sequence. This field is only used if KIND is ck_user. */
114 struct z_candidate *cand;
117 #define CONVERSION_RANK(NODE) \
118 ((NODE)->bad_p ? cr_bad \
119 : (NODE)->ellipsis_p ? cr_ellipsis \
120 : (NODE)->user_conv_p ? cr_user \
123 static struct obstack conversion_obstack;
124 static bool conversion_obstack_initialized;
126 static struct z_candidate * tourney (struct z_candidate *);
127 static int equal_functions (tree, tree);
128 static int joust (struct z_candidate *, struct z_candidate *, bool);
129 static int compare_ics (conversion *, conversion *);
130 static tree build_over_call (struct z_candidate *, int);
131 static tree build_java_interface_fn_ref (tree, tree);
132 #define convert_like(CONV, EXPR) \
133 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
134 /*issue_conversion_warnings=*/true, \
136 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
137 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
138 /*issue_conversion_warnings=*/true, \
140 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
142 static void op_error (enum tree_code, enum tree_code, tree, tree,
144 static tree build_object_call (tree, tree);
145 static tree resolve_args (tree);
146 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
147 static void print_z_candidate (const char *, struct z_candidate *);
148 static void print_z_candidates (struct z_candidate *);
149 static tree build_this (tree);
150 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
151 static bool any_strictly_viable (struct z_candidate *);
152 static struct z_candidate *add_template_candidate
153 (struct z_candidate **, tree, tree, tree, tree, tree,
154 tree, tree, int, unification_kind_t);
155 static struct z_candidate *add_template_candidate_real
156 (struct z_candidate **, tree, tree, tree, tree, tree,
157 tree, tree, int, tree, unification_kind_t);
158 static struct z_candidate *add_template_conv_candidate
159 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
160 static void add_builtin_candidates
161 (struct z_candidate **, enum tree_code, enum tree_code,
163 static void add_builtin_candidate
164 (struct z_candidate **, enum tree_code, enum tree_code,
165 tree, tree, tree, tree *, tree *, int);
166 static bool is_complete (tree);
167 static void build_builtin_candidate
168 (struct z_candidate **, tree, tree, tree, tree *, tree *,
170 static struct z_candidate *add_conv_candidate
171 (struct z_candidate **, tree, tree, tree, tree, tree);
172 static struct z_candidate *add_function_candidate
173 (struct z_candidate **, tree, tree, tree, tree, tree, int);
174 static conversion *implicit_conversion (tree, tree, tree, bool, int);
175 static conversion *standard_conversion (tree, tree, tree, bool, int);
176 static conversion *reference_binding (tree, tree, tree, int);
177 static conversion *build_conv (conversion_kind, tree, conversion *);
178 static bool is_subseq (conversion *, conversion *);
179 static tree maybe_handle_ref_bind (conversion **);
180 static void maybe_handle_implicit_object (conversion **);
181 static struct z_candidate *add_candidate
182 (struct z_candidate **, tree, tree, size_t,
183 conversion **, tree, tree, int);
184 static tree source_type (conversion *);
185 static void add_warning (struct z_candidate *, struct z_candidate *);
186 static bool reference_related_p (tree, tree);
187 static bool reference_compatible_p (tree, tree);
188 static conversion *convert_class_to_reference (tree, tree, tree);
189 static conversion *direct_reference_binding (tree, conversion *);
190 static bool promoted_arithmetic_type_p (tree);
191 static conversion *conditional_conversion (tree, tree);
192 static char *name_as_c_string (tree, tree, bool *);
193 static tree call_builtin_trap (void);
194 static tree prep_operand (tree);
195 static void add_candidates (tree, tree, tree, bool, tree, tree,
196 int, struct z_candidate **);
197 static conversion *merge_conversion_sequences (conversion *, conversion *);
198 static bool magic_varargs_p (tree);
199 typedef void (*diagnostic_fn_t) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
200 static tree build_temp (tree, tree, int, diagnostic_fn_t *);
201 static void check_constructor_callable (tree, tree);
203 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
204 NAME can take many forms... */
207 check_dtor_name (tree basetype, tree name)
209 /* Just accept something we've already complained about. */
210 if (name == error_mark_node)
213 if (TREE_CODE (name) == TYPE_DECL)
214 name = TREE_TYPE (name);
215 else if (TYPE_P (name))
217 else if (TREE_CODE (name) == IDENTIFIER_NODE)
219 if ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
220 || (TREE_CODE (basetype) == ENUMERAL_TYPE
221 && name == TYPE_IDENTIFIER (basetype)))
224 name = get_type_value (name);
230 template <class T> struct S { ~S(); };
234 NAME will be a class template. */
235 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
241 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
244 /* We want the address of a function or method. We avoid creating a
245 pointer-to-member function. */
248 build_addr_func (tree function)
250 tree type = TREE_TYPE (function);
252 /* We have to do these by hand to avoid real pointer to member
254 if (TREE_CODE (type) == METHOD_TYPE)
256 if (TREE_CODE (function) == OFFSET_REF)
258 tree object = build_address (TREE_OPERAND (function, 0));
259 return get_member_function_from_ptrfunc (&object,
260 TREE_OPERAND (function, 1));
262 function = build_address (function);
265 function = decay_conversion (function);
270 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
271 POINTER_TYPE to those. Note, pointer to member function types
272 (TYPE_PTRMEMFUNC_P) must be handled by our callers. */
275 build_call (tree function, tree parms)
277 int is_constructor = 0;
284 function = build_addr_func (function);
286 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
287 fntype = TREE_TYPE (TREE_TYPE (function));
288 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
289 || TREE_CODE (fntype) == METHOD_TYPE);
290 result_type = TREE_TYPE (fntype);
292 if (TREE_CODE (function) == ADDR_EXPR
293 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
295 decl = TREE_OPERAND (function, 0);
296 if (!TREE_USED (decl))
298 /* We invoke build_call directly for several library
299 functions. These may have been declared normally if
300 we're building libgcc, so we can't just check
302 gcc_assert (DECL_ARTIFICIAL (decl)
303 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
311 /* We check both the decl and the type; a function may be known not to
312 throw without being declared throw(). */
313 nothrow = ((decl && TREE_NOTHROW (decl))
314 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
316 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
317 current_function_returns_abnormally = 1;
319 if (decl && TREE_DEPRECATED (decl))
320 warn_deprecated_use (decl);
321 require_complete_eh_spec_types (fntype, decl);
323 if (decl && DECL_CONSTRUCTOR_P (decl))
326 /* Don't pass empty class objects by value. This is useful
327 for tags in STL, which are used to control overload resolution.
328 We don't need to handle other cases of copying empty classes. */
329 if (! decl || ! DECL_BUILT_IN (decl))
330 for (tmp = parms; tmp; tmp = TREE_CHAIN (tmp))
331 if (is_empty_class (TREE_TYPE (TREE_VALUE (tmp)))
332 && ! TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (tmp))))
334 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (TREE_VALUE (tmp)));
335 TREE_VALUE (tmp) = build2 (COMPOUND_EXPR, TREE_TYPE (t),
336 TREE_VALUE (tmp), t);
339 function = build3 (CALL_EXPR, result_type, function, parms, NULL_TREE);
340 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
341 TREE_NOTHROW (function) = nothrow;
346 /* Build something of the form ptr->method (args)
347 or object.method (args). This can also build
348 calls to constructors, and find friends.
350 Member functions always take their class variable
353 INSTANCE is a class instance.
355 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
357 PARMS help to figure out what that NAME really refers to.
359 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
360 down to the real instance type to use for access checking. We need this
361 information to get protected accesses correct.
363 FLAGS is the logical disjunction of zero or more LOOKUP_
364 flags. See cp-tree.h for more info.
366 If this is all OK, calls build_function_call with the resolved
369 This function must also handle being called to perform
370 initialization, promotion/coercion of arguments, and
371 instantiation of default parameters.
373 Note that NAME may refer to an instance variable name. If
374 `operator()()' is defined for the type of that field, then we return
377 /* New overloading code. */
379 typedef struct z_candidate z_candidate;
381 typedef struct candidate_warning candidate_warning;
382 struct candidate_warning {
384 candidate_warning *next;
388 /* The FUNCTION_DECL that will be called if this candidate is
389 selected by overload resolution. */
391 /* The arguments to use when calling this function. */
393 /* The implicit conversion sequences for each of the arguments to
396 /* The number of implicit conversion sequences. */
398 /* If FN is a user-defined conversion, the standard conversion
399 sequence from the type returned by FN to the desired destination
401 conversion *second_conv;
403 /* If FN is a member function, the binfo indicating the path used to
404 qualify the name of FN at the call site. This path is used to
405 determine whether or not FN is accessible if it is selected by
406 overload resolution. The DECL_CONTEXT of FN will always be a
407 (possibly improper) base of this binfo. */
409 /* If FN is a non-static member function, the binfo indicating the
410 subobject to which the `this' pointer should be converted if FN
411 is selected by overload resolution. The type pointed to the by
412 the `this' pointer must correspond to the most derived class
413 indicated by the CONVERSION_PATH. */
414 tree conversion_path;
416 candidate_warning *warnings;
420 /* Returns true iff T is a null pointer constant in the sense of
424 null_ptr_cst_p (tree t)
428 A null pointer constant is an integral constant expression
429 (_expr.const_) rvalue of integer type that evaluates to zero. */
430 t = integral_constant_value (t);
433 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t))
436 if (!TREE_OVERFLOW (t))
442 /* Returns nonzero if PARMLIST consists of only default parms and/or
446 sufficient_parms_p (tree parmlist)
448 for (; parmlist && parmlist != void_list_node;
449 parmlist = TREE_CHAIN (parmlist))
450 if (!TREE_PURPOSE (parmlist))
455 /* Allocate N bytes of memory from the conversion obstack. The memory
456 is zeroed before being returned. */
459 conversion_obstack_alloc (size_t n)
462 if (!conversion_obstack_initialized)
464 gcc_obstack_init (&conversion_obstack);
465 conversion_obstack_initialized = true;
467 p = obstack_alloc (&conversion_obstack, n);
472 /* Dynamically allocate a conversion. */
475 alloc_conversion (conversion_kind kind)
478 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
483 #ifdef ENABLE_CHECKING
485 /* Make sure that all memory on the conversion obstack has been
489 validate_conversion_obstack (void)
491 if (conversion_obstack_initialized)
492 gcc_assert ((obstack_next_free (&conversion_obstack)
493 == obstack_base (&conversion_obstack)));
496 #endif /* ENABLE_CHECKING */
498 /* Dynamically allocate an array of N conversions. */
501 alloc_conversions (size_t n)
503 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
507 build_conv (conversion_kind code, tree type, conversion *from)
510 conversion_rank rank = CONVERSION_RANK (from);
512 /* We can't use buildl1 here because CODE could be USER_CONV, which
513 takes two arguments. In that case, the caller is responsible for
514 filling in the second argument. */
515 t = alloc_conversion (code);
538 t->user_conv_p = (code == ck_user || from->user_conv_p);
539 t->bad_p = from->bad_p;
544 /* Build a representation of the identity conversion from EXPR to
545 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
548 build_identity_conv (tree type, tree expr)
552 c = alloc_conversion (ck_identity);
559 /* Converting from EXPR to TYPE was ambiguous in the sense that there
560 were multiple user-defined conversions to accomplish the job.
561 Build a conversion that indicates that ambiguity. */
564 build_ambiguous_conv (tree type, tree expr)
568 c = alloc_conversion (ck_ambig);
576 strip_top_quals (tree t)
578 if (TREE_CODE (t) == ARRAY_TYPE)
580 return cp_build_qualified_type (t, 0);
583 /* Returns the standard conversion path (see [conv]) from type FROM to type
584 TO, if any. For proper handling of null pointer constants, you must
585 also pass the expression EXPR to convert from. If C_CAST_P is true,
586 this conversion is coming from a C-style cast. */
589 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
592 enum tree_code fcode, tcode;
594 bool fromref = false;
596 to = non_reference (to);
597 if (TREE_CODE (from) == REFERENCE_TYPE)
600 from = TREE_TYPE (from);
602 to = strip_top_quals (to);
603 from = strip_top_quals (from);
605 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
606 && expr && type_unknown_p (expr))
608 expr = instantiate_type (to, expr, tf_conv);
609 if (expr == error_mark_node)
611 from = TREE_TYPE (expr);
614 fcode = TREE_CODE (from);
615 tcode = TREE_CODE (to);
617 conv = build_identity_conv (from, expr);
618 if (fcode == FUNCTION_TYPE)
620 from = build_pointer_type (from);
621 fcode = TREE_CODE (from);
622 conv = build_conv (ck_lvalue, from, conv);
624 else if (fcode == ARRAY_TYPE)
626 from = build_pointer_type (TREE_TYPE (from));
627 fcode = TREE_CODE (from);
628 conv = build_conv (ck_lvalue, from, conv);
630 else if (fromref || (expr && lvalue_p (expr)))
635 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
637 from = strip_top_quals (bitfield_type);
639 conv = build_conv (ck_rvalue, from, conv);
642 /* Allow conversion between `__complex__' data types. */
643 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
645 /* The standard conversion sequence to convert FROM to TO is
646 the standard conversion sequence to perform componentwise
648 conversion *part_conv = standard_conversion
649 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
653 conv = build_conv (part_conv->kind, to, conv);
654 conv->rank = part_conv->rank;
662 if (same_type_p (from, to))
665 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
666 && expr && null_ptr_cst_p (expr))
667 conv = build_conv (ck_std, to, conv);
668 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
669 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
671 /* For backwards brain damage compatibility, allow interconversion of
672 pointers and integers with a pedwarn. */
673 conv = build_conv (ck_std, to, conv);
676 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
678 /* For backwards brain damage compatibility, allow interconversion of
679 enums and integers with a pedwarn. */
680 conv = build_conv (ck_std, to, conv);
683 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
684 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
689 if (tcode == POINTER_TYPE
690 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
693 else if (VOID_TYPE_P (TREE_TYPE (to))
694 && !TYPE_PTRMEM_P (from)
695 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
697 from = build_pointer_type
698 (cp_build_qualified_type (void_type_node,
699 cp_type_quals (TREE_TYPE (from))));
700 conv = build_conv (ck_ptr, from, conv);
702 else if (TYPE_PTRMEM_P (from))
704 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
705 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
707 if (DERIVED_FROM_P (fbase, tbase)
708 && (same_type_ignoring_top_level_qualifiers_p
709 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
710 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
712 from = build_ptrmem_type (tbase,
713 TYPE_PTRMEM_POINTED_TO_TYPE (from));
714 conv = build_conv (ck_pmem, from, conv);
716 else if (!same_type_p (fbase, tbase))
719 else if (IS_AGGR_TYPE (TREE_TYPE (from))
720 && IS_AGGR_TYPE (TREE_TYPE (to))
723 An rvalue of type "pointer to cv D," where D is a
724 class type, can be converted to an rvalue of type
725 "pointer to cv B," where B is a base class (clause
726 _class.derived_) of D. If B is an inaccessible
727 (clause _class.access_) or ambiguous
728 (_class.member.lookup_) base class of D, a program
729 that necessitates this conversion is ill-formed.
730 Therefore, we use DERIVED_FROM_P, and do not check
731 access or uniqueness. */
732 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))
733 /* If FROM is not yet complete, then we must be parsing
734 the body of a class. We know what's derived from
735 what, but we can't actually perform a
736 derived-to-base conversion. For example, in:
738 struct D : public B {
739 static const int i = sizeof((B*)(D*)0);
742 the D*-to-B* conversion is a reinterpret_cast, not a
744 && COMPLETE_TYPE_P (TREE_TYPE (from)))
747 cp_build_qualified_type (TREE_TYPE (to),
748 cp_type_quals (TREE_TYPE (from)));
749 from = build_pointer_type (from);
750 conv = build_conv (ck_ptr, from, conv);
754 if (tcode == POINTER_TYPE)
756 to_pointee = TREE_TYPE (to);
757 from_pointee = TREE_TYPE (from);
761 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
762 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
765 if (same_type_p (from, to))
767 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
768 /* In a C-style cast, we ignore CV-qualification because we
769 are allowed to perform a static_cast followed by a
771 conv = build_conv (ck_qual, to, conv);
772 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
773 conv = build_conv (ck_qual, to, conv);
774 else if (expr && string_conv_p (to, expr, 0))
775 /* converting from string constant to char *. */
776 conv = build_conv (ck_qual, to, conv);
777 else if (ptr_reasonably_similar (to_pointee, from_pointee))
779 conv = build_conv (ck_ptr, to, conv);
787 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
789 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
790 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
791 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
792 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
794 if (!DERIVED_FROM_P (fbase, tbase)
795 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
796 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
797 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
798 || cp_type_quals (fbase) != cp_type_quals (tbase))
801 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
802 from = build_method_type_directly (from,
804 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
805 from = build_ptrmemfunc_type (build_pointer_type (from));
806 conv = build_conv (ck_pmem, from, conv);
809 else if (tcode == BOOLEAN_TYPE)
813 An rvalue of arithmetic, enumeration, pointer, or pointer to
814 member type can be converted to an rvalue of type bool. */
815 if (ARITHMETIC_TYPE_P (from)
816 || fcode == ENUMERAL_TYPE
817 || fcode == POINTER_TYPE
818 || TYPE_PTR_TO_MEMBER_P (from))
820 conv = build_conv (ck_std, to, conv);
821 if (fcode == POINTER_TYPE
822 || TYPE_PTRMEM_P (from)
823 || (TYPE_PTRMEMFUNC_P (from)
824 && conv->rank < cr_pbool))
825 conv->rank = cr_pbool;
831 /* We don't check for ENUMERAL_TYPE here because there are no standard
832 conversions to enum type. */
833 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
834 || tcode == REAL_TYPE)
836 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
838 conv = build_conv (ck_std, to, conv);
840 /* Give this a better rank if it's a promotion. */
841 if (same_type_p (to, type_promotes_to (from))
842 && conv->u.next->rank <= cr_promotion)
843 conv->rank = cr_promotion;
845 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
846 && vector_types_convertible_p (from, to, false))
847 return build_conv (ck_std, to, conv);
848 else if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE)
849 && IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
850 && is_properly_derived_from (from, to))
852 if (conv->kind == ck_rvalue)
854 conv = build_conv (ck_base, to, conv);
855 /* The derived-to-base conversion indicates the initialization
856 of a parameter with base type from an object of a derived
857 type. A temporary object is created to hold the result of
859 conv->need_temporary_p = true;
867 /* Returns nonzero if T1 is reference-related to T2. */
870 reference_related_p (tree t1, tree t2)
872 t1 = TYPE_MAIN_VARIANT (t1);
873 t2 = TYPE_MAIN_VARIANT (t2);
877 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
878 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
880 return (same_type_p (t1, t2)
881 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
882 && DERIVED_FROM_P (t1, t2)));
885 /* Returns nonzero if T1 is reference-compatible with T2. */
888 reference_compatible_p (tree t1, tree t2)
892 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
893 reference-related to T2 and cv1 is the same cv-qualification as,
894 or greater cv-qualification than, cv2. */
895 return (reference_related_p (t1, t2)
896 && at_least_as_qualified_p (t1, t2));
899 /* Determine whether or not the EXPR (of class type S) can be
900 converted to T as in [over.match.ref]. */
903 convert_class_to_reference (tree t, tree s, tree expr)
909 struct z_candidate *candidates;
910 struct z_candidate *cand;
913 conversions = lookup_conversions (s);
919 Assuming that "cv1 T" is the underlying type of the reference
920 being initialized, and "cv S" is the type of the initializer
921 expression, with S a class type, the candidate functions are
924 --The conversion functions of S and its base classes are
925 considered. Those that are not hidden within S and yield type
926 "reference to cv2 T2", where "cv1 T" is reference-compatible
927 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
929 The argument list has one argument, which is the initializer
934 /* Conceptually, we should take the address of EXPR and put it in
935 the argument list. Unfortunately, however, that can result in
936 error messages, which we should not issue now because we are just
937 trying to find a conversion operator. Therefore, we use NULL,
938 cast to the appropriate type. */
939 arglist = build_int_cst (build_pointer_type (s), 0);
940 arglist = build_tree_list (NULL_TREE, arglist);
942 reference_type = build_reference_type (t);
946 tree fns = TREE_VALUE (conversions);
948 for (; fns; fns = OVL_NEXT (fns))
950 tree f = OVL_CURRENT (fns);
951 tree t2 = TREE_TYPE (TREE_TYPE (f));
955 /* If this is a template function, try to get an exact
957 if (TREE_CODE (f) == TEMPLATE_DECL)
959 cand = add_template_candidate (&candidates,
965 TREE_PURPOSE (conversions),
971 /* Now, see if the conversion function really returns
972 an lvalue of the appropriate type. From the
973 point of view of unification, simply returning an
974 rvalue of the right type is good enough. */
976 t2 = TREE_TYPE (TREE_TYPE (f));
977 if (TREE_CODE (t2) != REFERENCE_TYPE
978 || !reference_compatible_p (t, TREE_TYPE (t2)))
980 candidates = candidates->next;
985 else if (TREE_CODE (t2) == REFERENCE_TYPE
986 && reference_compatible_p (t, TREE_TYPE (t2)))
987 cand = add_function_candidate (&candidates, f, s, arglist,
989 TREE_PURPOSE (conversions),
994 conversion *identity_conv;
995 /* Build a standard conversion sequence indicating the
996 binding from the reference type returned by the
997 function to the desired REFERENCE_TYPE. */
999 = build_identity_conv (TREE_TYPE (TREE_TYPE
1000 (TREE_TYPE (cand->fn))),
1003 = (direct_reference_binding
1004 (reference_type, identity_conv));
1005 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1008 conversions = TREE_CHAIN (conversions);
1011 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1012 /* If none of the conversion functions worked out, let our caller
1017 cand = tourney (candidates);
1021 /* Now that we know that this is the function we're going to use fix
1022 the dummy first argument. */
1023 cand->args = tree_cons (NULL_TREE,
1025 TREE_CHAIN (cand->args));
1027 /* Build a user-defined conversion sequence representing the
1029 conv = build_conv (ck_user,
1030 TREE_TYPE (TREE_TYPE (cand->fn)),
1031 build_identity_conv (TREE_TYPE (expr), expr));
1034 /* Merge it with the standard conversion sequence from the
1035 conversion function's return type to the desired type. */
1036 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1038 if (cand->viable == -1)
1041 return cand->second_conv;
1044 /* A reference of the indicated TYPE is being bound directly to the
1045 expression represented by the implicit conversion sequence CONV.
1046 Return a conversion sequence for this binding. */
1049 direct_reference_binding (tree type, conversion *conv)
1053 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1054 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1056 t = TREE_TYPE (type);
1060 When a parameter of reference type binds directly
1061 (_dcl.init.ref_) to an argument expression, the implicit
1062 conversion sequence is the identity conversion, unless the
1063 argument expression has a type that is a derived class of the
1064 parameter type, in which case the implicit conversion sequence is
1065 a derived-to-base Conversion.
1067 If the parameter binds directly to the result of applying a
1068 conversion function to the argument expression, the implicit
1069 conversion sequence is a user-defined conversion sequence
1070 (_over.ics.user_), with the second standard conversion sequence
1071 either an identity conversion or, if the conversion function
1072 returns an entity of a type that is a derived class of the
1073 parameter type, a derived-to-base conversion. */
1074 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1076 /* Represent the derived-to-base conversion. */
1077 conv = build_conv (ck_base, t, conv);
1078 /* We will actually be binding to the base-class subobject in
1079 the derived class, so we mark this conversion appropriately.
1080 That way, convert_like knows not to generate a temporary. */
1081 conv->need_temporary_p = false;
1083 return build_conv (ck_ref_bind, type, conv);
1086 /* Returns the conversion path from type FROM to reference type TO for
1087 purposes of reference binding. For lvalue binding, either pass a
1088 reference type to FROM or an lvalue expression to EXPR. If the
1089 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1090 the conversion returned. */
1093 reference_binding (tree rto, tree rfrom, tree expr, int flags)
1095 conversion *conv = NULL;
1096 tree to = TREE_TYPE (rto);
1100 cp_lvalue_kind lvalue_p = clk_none;
1102 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1104 expr = instantiate_type (to, expr, tf_none);
1105 if (expr == error_mark_node)
1107 from = TREE_TYPE (expr);
1110 if (TREE_CODE (from) == REFERENCE_TYPE)
1112 /* Anything with reference type is an lvalue. */
1113 lvalue_p = clk_ordinary;
1114 from = TREE_TYPE (from);
1117 lvalue_p = real_lvalue_p (expr);
1119 /* Figure out whether or not the types are reference-related and
1120 reference compatible. We have do do this after stripping
1121 references from FROM. */
1122 related_p = reference_related_p (to, from);
1123 compatible_p = reference_compatible_p (to, from);
1125 if (lvalue_p && compatible_p)
1129 If the initializer expression
1131 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1132 is reference-compatible with "cv2 T2,"
1134 the reference is bound directly to the initializer expression
1136 conv = build_identity_conv (from, expr);
1137 conv = direct_reference_binding (rto, conv);
1138 if ((lvalue_p & clk_bitfield) != 0
1139 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1140 /* For the purposes of overload resolution, we ignore the fact
1141 this expression is a bitfield or packed field. (In particular,
1142 [over.ics.ref] says specifically that a function with a
1143 non-const reference parameter is viable even if the
1144 argument is a bitfield.)
1146 However, when we actually call the function we must create
1147 a temporary to which to bind the reference. If the
1148 reference is volatile, or isn't const, then we cannot make
1149 a temporary, so we just issue an error when the conversion
1151 conv->need_temporary_p = true;
1155 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1159 If the initializer expression
1161 -- has a class type (i.e., T2 is a class type) can be
1162 implicitly converted to an lvalue of type "cv3 T3," where
1163 "cv1 T1" is reference-compatible with "cv3 T3". (this
1164 conversion is selected by enumerating the applicable
1165 conversion functions (_over.match.ref_) and choosing the
1166 best one through overload resolution. (_over.match_).
1168 the reference is bound to the lvalue result of the conversion
1169 in the second case. */
1170 conv = convert_class_to_reference (to, from, expr);
1175 /* From this point on, we conceptually need temporaries, even if we
1176 elide them. Only the cases above are "direct bindings". */
1177 if (flags & LOOKUP_NO_TEMP_BIND)
1182 When a parameter of reference type is not bound directly to an
1183 argument expression, the conversion sequence is the one required
1184 to convert the argument expression to the underlying type of the
1185 reference according to _over.best.ics_. Conceptually, this
1186 conversion sequence corresponds to copy-initializing a temporary
1187 of the underlying type with the argument expression. Any
1188 difference in top-level cv-qualification is subsumed by the
1189 initialization itself and does not constitute a conversion. */
1193 Otherwise, the reference shall be to a non-volatile const type. */
1194 if (!CP_TYPE_CONST_NON_VOLATILE_P (to))
1199 If the initializer expression is an rvalue, with T2 a class type,
1200 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1201 is bound in one of the following ways:
1203 -- The reference is bound to the object represented by the rvalue
1204 or to a sub-object within that object.
1208 We use the first alternative. The implicit conversion sequence
1209 is supposed to be same as we would obtain by generating a
1210 temporary. Fortunately, if the types are reference compatible,
1211 then this is either an identity conversion or the derived-to-base
1212 conversion, just as for direct binding. */
1213 if (CLASS_TYPE_P (from) && compatible_p)
1215 conv = build_identity_conv (from, expr);
1216 conv = direct_reference_binding (rto, conv);
1217 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1218 conv->u.next->check_copy_constructor_p = true;
1224 Otherwise, a temporary of type "cv1 T1" is created and
1225 initialized from the initializer expression using the rules for a
1226 non-reference copy initialization. If T1 is reference-related to
1227 T2, cv1 must be the same cv-qualification as, or greater
1228 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1229 if (related_p && !at_least_as_qualified_p (to, from))
1232 conv = implicit_conversion (to, from, expr, /*c_cast_p=*/false,
1237 conv = build_conv (ck_ref_bind, rto, conv);
1238 /* This reference binding, unlike those above, requires the
1239 creation of a temporary. */
1240 conv->need_temporary_p = true;
1245 /* Returns the implicit conversion sequence (see [over.ics]) from type
1246 FROM to type TO. The optional expression EXPR may affect the
1247 conversion. FLAGS are the usual overloading flags. Only
1248 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1249 conversion is coming from a C-style cast. */
1252 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1257 if (from == error_mark_node || to == error_mark_node
1258 || expr == error_mark_node)
1261 if (TREE_CODE (to) == REFERENCE_TYPE)
1262 conv = reference_binding (to, from, expr, flags);
1264 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1269 if (expr != NULL_TREE
1270 && (IS_AGGR_TYPE (from)
1271 || IS_AGGR_TYPE (to))
1272 && (flags & LOOKUP_NO_CONVERSION) == 0)
1274 struct z_candidate *cand;
1276 cand = build_user_type_conversion_1
1277 (to, expr, LOOKUP_ONLYCONVERTING);
1279 conv = cand->second_conv;
1281 /* We used to try to bind a reference to a temporary here, but that
1282 is now handled by the recursive call to this function at the end
1283 of reference_binding. */
1290 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1293 static struct z_candidate *
1294 add_candidate (struct z_candidate **candidates,
1296 size_t num_convs, conversion **convs,
1297 tree access_path, tree conversion_path,
1300 struct z_candidate *cand = (struct z_candidate *)
1301 conversion_obstack_alloc (sizeof (struct z_candidate));
1305 cand->convs = convs;
1306 cand->num_convs = num_convs;
1307 cand->access_path = access_path;
1308 cand->conversion_path = conversion_path;
1309 cand->viable = viable;
1310 cand->next = *candidates;
1316 /* Create an overload candidate for the function or method FN called with
1317 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1318 to implicit_conversion.
1320 CTYPE, if non-NULL, is the type we want to pretend this function
1321 comes from for purposes of overload resolution. */
1323 static struct z_candidate *
1324 add_function_candidate (struct z_candidate **candidates,
1325 tree fn, tree ctype, tree arglist,
1326 tree access_path, tree conversion_path,
1329 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1332 tree parmnode, argnode;
1336 /* At this point we should not see any functions which haven't been
1337 explicitly declared, except for friend functions which will have
1338 been found using argument dependent lookup. */
1339 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1341 /* The `this', `in_chrg' and VTT arguments to constructors are not
1342 considered in overload resolution. */
1343 if (DECL_CONSTRUCTOR_P (fn))
1345 parmlist = skip_artificial_parms_for (fn, parmlist);
1346 orig_arglist = arglist;
1347 arglist = skip_artificial_parms_for (fn, arglist);
1350 orig_arglist = arglist;
1352 len = list_length (arglist);
1353 convs = alloc_conversions (len);
1355 /* 13.3.2 - Viable functions [over.match.viable]
1356 First, to be a viable function, a candidate function shall have enough
1357 parameters to agree in number with the arguments in the list.
1359 We need to check this first; otherwise, checking the ICSes might cause
1360 us to produce an ill-formed template instantiation. */
1362 parmnode = parmlist;
1363 for (i = 0; i < len; ++i)
1365 if (parmnode == NULL_TREE || parmnode == void_list_node)
1367 parmnode = TREE_CHAIN (parmnode);
1370 if (i < len && parmnode)
1373 /* Make sure there are default args for the rest of the parms. */
1374 else if (!sufficient_parms_p (parmnode))
1380 /* Second, for F to be a viable function, there shall exist for each
1381 argument an implicit conversion sequence that converts that argument
1382 to the corresponding parameter of F. */
1384 parmnode = parmlist;
1387 for (i = 0; i < len; ++i)
1389 tree arg = TREE_VALUE (argnode);
1390 tree argtype = lvalue_type (arg);
1394 if (parmnode == void_list_node)
1397 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1398 && ! DECL_CONSTRUCTOR_P (fn));
1402 tree parmtype = TREE_VALUE (parmnode);
1404 /* The type of the implicit object parameter ('this') for
1405 overload resolution is not always the same as for the
1406 function itself; conversion functions are considered to
1407 be members of the class being converted, and functions
1408 introduced by a using-declaration are considered to be
1409 members of the class that uses them.
1411 Since build_over_call ignores the ICS for the `this'
1412 parameter, we can just change the parm type. */
1413 if (ctype && is_this)
1416 = build_qualified_type (ctype,
1417 TYPE_QUALS (TREE_TYPE (parmtype)));
1418 parmtype = build_pointer_type (parmtype);
1421 t = implicit_conversion (parmtype, argtype, arg,
1422 /*c_cast_p=*/false, flags);
1426 t = build_identity_conv (argtype, arg);
1427 t->ellipsis_p = true;
1444 parmnode = TREE_CHAIN (parmnode);
1445 argnode = TREE_CHAIN (argnode);
1449 return add_candidate (candidates, fn, orig_arglist, len, convs,
1450 access_path, conversion_path, viable);
1453 /* Create an overload candidate for the conversion function FN which will
1454 be invoked for expression OBJ, producing a pointer-to-function which
1455 will in turn be called with the argument list ARGLIST, and add it to
1456 CANDIDATES. FLAGS is passed on to implicit_conversion.
1458 Actually, we don't really care about FN; we care about the type it
1459 converts to. There may be multiple conversion functions that will
1460 convert to that type, and we rely on build_user_type_conversion_1 to
1461 choose the best one; so when we create our candidate, we record the type
1462 instead of the function. */
1464 static struct z_candidate *
1465 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1466 tree arglist, tree access_path, tree conversion_path)
1468 tree totype = TREE_TYPE (TREE_TYPE (fn));
1469 int i, len, viable, flags;
1470 tree parmlist, parmnode, argnode;
1473 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1474 parmlist = TREE_TYPE (parmlist);
1475 parmlist = TYPE_ARG_TYPES (parmlist);
1477 len = list_length (arglist) + 1;
1478 convs = alloc_conversions (len);
1479 parmnode = parmlist;
1482 flags = LOOKUP_NORMAL;
1484 /* Don't bother looking up the same type twice. */
1485 if (*candidates && (*candidates)->fn == totype)
1488 for (i = 0; i < len; ++i)
1490 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1491 tree argtype = lvalue_type (arg);
1495 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1497 else if (parmnode == void_list_node)
1500 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1501 /*c_cast_p=*/false, flags);
1504 t = build_identity_conv (argtype, arg);
1505 t->ellipsis_p = true;
1519 parmnode = TREE_CHAIN (parmnode);
1520 argnode = TREE_CHAIN (argnode);
1526 if (!sufficient_parms_p (parmnode))
1529 return add_candidate (candidates, totype, arglist, len, convs,
1530 access_path, conversion_path, viable);
1534 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1535 tree type1, tree type2, tree *args, tree *argtypes,
1547 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1548 convs = alloc_conversions (num_convs);
1550 for (i = 0; i < 2; ++i)
1555 t = implicit_conversion (types[i], argtypes[i], args[i],
1556 /*c_cast_p=*/false, flags);
1560 /* We need something for printing the candidate. */
1561 t = build_identity_conv (types[i], NULL_TREE);
1568 /* For COND_EXPR we rearranged the arguments; undo that now. */
1571 convs[2] = convs[1];
1572 convs[1] = convs[0];
1573 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1574 /*c_cast_p=*/false, flags);
1581 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1583 /*access_path=*/NULL_TREE,
1584 /*conversion_path=*/NULL_TREE,
1589 is_complete (tree t)
1591 return COMPLETE_TYPE_P (complete_type (t));
1594 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1597 promoted_arithmetic_type_p (tree type)
1601 In this section, the term promoted integral type is used to refer
1602 to those integral types which are preserved by integral promotion
1603 (including e.g. int and long but excluding e.g. char).
1604 Similarly, the term promoted arithmetic type refers to promoted
1605 integral types plus floating types. */
1606 return ((INTEGRAL_TYPE_P (type)
1607 && same_type_p (type_promotes_to (type), type))
1608 || TREE_CODE (type) == REAL_TYPE);
1611 /* Create any builtin operator overload candidates for the operator in
1612 question given the converted operand types TYPE1 and TYPE2. The other
1613 args are passed through from add_builtin_candidates to
1614 build_builtin_candidate.
1616 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1617 If CODE is requires candidates operands of the same type of the kind
1618 of which TYPE1 and TYPE2 are, we add both candidates
1619 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1622 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1623 enum tree_code code2, tree fnname, tree type1,
1624 tree type2, tree *args, tree *argtypes, int flags)
1628 case POSTINCREMENT_EXPR:
1629 case POSTDECREMENT_EXPR:
1630 args[1] = integer_zero_node;
1631 type2 = integer_type_node;
1640 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1641 and VQ is either volatile or empty, there exist candidate operator
1642 functions of the form
1643 VQ T& operator++(VQ T&);
1644 T operator++(VQ T&, int);
1645 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1646 type other than bool, and VQ is either volatile or empty, there exist
1647 candidate operator functions of the form
1648 VQ T& operator--(VQ T&);
1649 T operator--(VQ T&, int);
1650 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1651 complete object type, and VQ is either volatile or empty, there exist
1652 candidate operator functions of the form
1653 T*VQ& operator++(T*VQ&);
1654 T*VQ& operator--(T*VQ&);
1655 T* operator++(T*VQ&, int);
1656 T* operator--(T*VQ&, int); */
1658 case POSTDECREMENT_EXPR:
1659 case PREDECREMENT_EXPR:
1660 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1662 case POSTINCREMENT_EXPR:
1663 case PREINCREMENT_EXPR:
1664 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1666 type1 = build_reference_type (type1);
1671 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1672 exist candidate operator functions of the form
1676 8 For every function type T, there exist candidate operator functions of
1678 T& operator*(T*); */
1681 if (TREE_CODE (type1) == POINTER_TYPE
1682 && (TYPE_PTROB_P (type1)
1683 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1687 /* 9 For every type T, there exist candidate operator functions of the form
1690 10For every promoted arithmetic type T, there exist candidate operator
1691 functions of the form
1695 case UNARY_PLUS_EXPR: /* unary + */
1696 if (TREE_CODE (type1) == POINTER_TYPE)
1699 if (ARITHMETIC_TYPE_P (type1))
1703 /* 11For every promoted integral type T, there exist candidate operator
1704 functions of the form
1708 if (INTEGRAL_TYPE_P (type1))
1712 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1713 is the same type as C2 or is a derived class of C2, T is a complete
1714 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1715 there exist candidate operator functions of the form
1716 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1717 where CV12 is the union of CV1 and CV2. */
1720 if (TREE_CODE (type1) == POINTER_TYPE
1721 && TYPE_PTR_TO_MEMBER_P (type2))
1723 tree c1 = TREE_TYPE (type1);
1724 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1726 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1727 && (TYPE_PTRMEMFUNC_P (type2)
1728 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1733 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1734 didate operator functions of the form
1739 bool operator<(L, R);
1740 bool operator>(L, R);
1741 bool operator<=(L, R);
1742 bool operator>=(L, R);
1743 bool operator==(L, R);
1744 bool operator!=(L, R);
1745 where LR is the result of the usual arithmetic conversions between
1748 14For every pair of types T and I, where T is a cv-qualified or cv-
1749 unqualified complete object type and I is a promoted integral type,
1750 there exist candidate operator functions of the form
1751 T* operator+(T*, I);
1752 T& operator[](T*, I);
1753 T* operator-(T*, I);
1754 T* operator+(I, T*);
1755 T& operator[](I, T*);
1757 15For every T, where T is a pointer to complete object type, there exist
1758 candidate operator functions of the form112)
1759 ptrdiff_t operator-(T, T);
1761 16For every pointer or enumeration type T, there exist candidate operator
1762 functions of the form
1763 bool operator<(T, T);
1764 bool operator>(T, T);
1765 bool operator<=(T, T);
1766 bool operator>=(T, T);
1767 bool operator==(T, T);
1768 bool operator!=(T, T);
1770 17For every pointer to member type T, there exist candidate operator
1771 functions of the form
1772 bool operator==(T, T);
1773 bool operator!=(T, T); */
1776 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1778 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1780 type2 = ptrdiff_type_node;
1784 case TRUNC_DIV_EXPR:
1785 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1791 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1792 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1794 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1799 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1811 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1813 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1815 if (TREE_CODE (type1) == ENUMERAL_TYPE
1816 && TREE_CODE (type2) == ENUMERAL_TYPE)
1818 if (TYPE_PTR_P (type1)
1819 && null_ptr_cst_p (args[1])
1820 && !uses_template_parms (type1))
1825 if (null_ptr_cst_p (args[0])
1826 && TYPE_PTR_P (type2)
1827 && !uses_template_parms (type2))
1835 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1838 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1840 type1 = ptrdiff_type_node;
1843 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1845 type2 = ptrdiff_type_node;
1850 /* 18For every pair of promoted integral types L and R, there exist candi-
1851 date operator functions of the form
1858 where LR is the result of the usual arithmetic conversions between
1861 case TRUNC_MOD_EXPR:
1867 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1871 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1872 type, VQ is either volatile or empty, and R is a promoted arithmetic
1873 type, there exist candidate operator functions of the form
1874 VQ L& operator=(VQ L&, R);
1875 VQ L& operator*=(VQ L&, R);
1876 VQ L& operator/=(VQ L&, R);
1877 VQ L& operator+=(VQ L&, R);
1878 VQ L& operator-=(VQ L&, R);
1880 20For every pair T, VQ), where T is any type and VQ is either volatile
1881 or empty, there exist candidate operator functions of the form
1882 T*VQ& operator=(T*VQ&, T*);
1884 21For every pair T, VQ), where T is a pointer to member type and VQ is
1885 either volatile or empty, there exist candidate operator functions of
1887 VQ T& operator=(VQ T&, T);
1889 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1890 unqualified complete object type, VQ is either volatile or empty, and
1891 I is a promoted integral type, there exist candidate operator func-
1893 T*VQ& operator+=(T*VQ&, I);
1894 T*VQ& operator-=(T*VQ&, I);
1896 23For every triple L, VQ, R), where L is an integral or enumeration
1897 type, VQ is either volatile or empty, and R is a promoted integral
1898 type, there exist candidate operator functions of the form
1900 VQ L& operator%=(VQ L&, R);
1901 VQ L& operator<<=(VQ L&, R);
1902 VQ L& operator>>=(VQ L&, R);
1903 VQ L& operator&=(VQ L&, R);
1904 VQ L& operator^=(VQ L&, R);
1905 VQ L& operator|=(VQ L&, R); */
1912 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1914 type2 = ptrdiff_type_node;
1918 case TRUNC_DIV_EXPR:
1919 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1923 case TRUNC_MOD_EXPR:
1929 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1934 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1936 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1937 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1938 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1939 || ((TYPE_PTRMEMFUNC_P (type1)
1940 || TREE_CODE (type1) == POINTER_TYPE)
1941 && null_ptr_cst_p (args[1])))
1951 type1 = build_reference_type (type1);
1957 For every pair of promoted arithmetic types L and R, there
1958 exist candidate operator functions of the form
1960 LR operator?(bool, L, R);
1962 where LR is the result of the usual arithmetic conversions
1963 between types L and R.
1965 For every type T, where T is a pointer or pointer-to-member
1966 type, there exist candidate operator functions of the form T
1967 operator?(bool, T, T); */
1969 if (promoted_arithmetic_type_p (type1)
1970 && promoted_arithmetic_type_p (type2))
1974 /* Otherwise, the types should be pointers. */
1975 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
1976 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
1979 /* We don't check that the two types are the same; the logic
1980 below will actually create two candidates; one in which both
1981 parameter types are TYPE1, and one in which both parameter
1989 /* If we're dealing with two pointer types or two enumeral types,
1990 we need candidates for both of them. */
1991 if (type2 && !same_type_p (type1, type2)
1992 && TREE_CODE (type1) == TREE_CODE (type2)
1993 && (TREE_CODE (type1) == REFERENCE_TYPE
1994 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1995 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1996 || TYPE_PTRMEMFUNC_P (type1)
1997 || IS_AGGR_TYPE (type1)
1998 || TREE_CODE (type1) == ENUMERAL_TYPE))
2000 build_builtin_candidate
2001 (candidates, fnname, type1, type1, args, argtypes, flags);
2002 build_builtin_candidate
2003 (candidates, fnname, type2, type2, args, argtypes, flags);
2007 build_builtin_candidate
2008 (candidates, fnname, type1, type2, args, argtypes, flags);
2012 type_decays_to (tree type)
2014 if (TREE_CODE (type) == ARRAY_TYPE)
2015 return build_pointer_type (TREE_TYPE (type));
2016 if (TREE_CODE (type) == FUNCTION_TYPE)
2017 return build_pointer_type (type);
2021 /* There are three conditions of builtin candidates:
2023 1) bool-taking candidates. These are the same regardless of the input.
2024 2) pointer-pair taking candidates. These are generated for each type
2025 one of the input types converts to.
2026 3) arithmetic candidates. According to the standard, we should generate
2027 all of these, but I'm trying not to...
2029 Here we generate a superset of the possible candidates for this particular
2030 case. That is a subset of the full set the standard defines, plus some
2031 other cases which the standard disallows. add_builtin_candidate will
2032 filter out the invalid set. */
2035 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2036 enum tree_code code2, tree fnname, tree *args,
2041 tree type, argtypes[3];
2042 /* TYPES[i] is the set of possible builtin-operator parameter types
2043 we will consider for the Ith argument. These are represented as
2044 a TREE_LIST; the TREE_VALUE of each node is the potential
2048 for (i = 0; i < 3; ++i)
2051 argtypes[i] = lvalue_type (args[i]);
2053 argtypes[i] = NULL_TREE;
2058 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2059 and VQ is either volatile or empty, there exist candidate operator
2060 functions of the form
2061 VQ T& operator++(VQ T&); */
2063 case POSTINCREMENT_EXPR:
2064 case PREINCREMENT_EXPR:
2065 case POSTDECREMENT_EXPR:
2066 case PREDECREMENT_EXPR:
2071 /* 24There also exist candidate operator functions of the form
2072 bool operator!(bool);
2073 bool operator&&(bool, bool);
2074 bool operator||(bool, bool); */
2076 case TRUTH_NOT_EXPR:
2077 build_builtin_candidate
2078 (candidates, fnname, boolean_type_node,
2079 NULL_TREE, args, argtypes, flags);
2082 case TRUTH_ORIF_EXPR:
2083 case TRUTH_ANDIF_EXPR:
2084 build_builtin_candidate
2085 (candidates, fnname, boolean_type_node,
2086 boolean_type_node, args, argtypes, flags);
2108 types[0] = types[1] = NULL_TREE;
2110 for (i = 0; i < 2; ++i)
2114 else if (IS_AGGR_TYPE (argtypes[i]))
2118 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2121 convs = lookup_conversions (argtypes[i]);
2123 if (code == COND_EXPR)
2125 if (real_lvalue_p (args[i]))
2126 types[i] = tree_cons
2127 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2129 types[i] = tree_cons
2130 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2136 for (; convs; convs = TREE_CHAIN (convs))
2138 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2141 && (TREE_CODE (type) != REFERENCE_TYPE
2142 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2145 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2146 types[i] = tree_cons (NULL_TREE, type, types[i]);
2148 type = non_reference (type);
2149 if (i != 0 || ! ref1)
2151 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2152 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2153 types[i] = tree_cons (NULL_TREE, type, types[i]);
2154 if (INTEGRAL_TYPE_P (type))
2155 type = type_promotes_to (type);
2158 if (! value_member (type, types[i]))
2159 types[i] = tree_cons (NULL_TREE, type, types[i]);
2164 if (code == COND_EXPR && real_lvalue_p (args[i]))
2165 types[i] = tree_cons
2166 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2167 type = non_reference (argtypes[i]);
2168 if (i != 0 || ! ref1)
2170 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2171 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2172 types[i] = tree_cons (NULL_TREE, type, types[i]);
2173 if (INTEGRAL_TYPE_P (type))
2174 type = type_promotes_to (type);
2176 types[i] = tree_cons (NULL_TREE, type, types[i]);
2180 /* Run through the possible parameter types of both arguments,
2181 creating candidates with those parameter types. */
2182 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2185 for (type = types[1]; type; type = TREE_CHAIN (type))
2186 add_builtin_candidate
2187 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2188 TREE_VALUE (type), args, argtypes, flags);
2190 add_builtin_candidate
2191 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2192 NULL_TREE, args, argtypes, flags);
2197 /* If TMPL can be successfully instantiated as indicated by
2198 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2200 TMPL is the template. EXPLICIT_TARGS are any explicit template
2201 arguments. ARGLIST is the arguments provided at the call-site.
2202 The RETURN_TYPE is the desired type for conversion operators. If
2203 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2204 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2205 add_conv_candidate. */
2207 static struct z_candidate*
2208 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2209 tree ctype, tree explicit_targs, tree arglist,
2210 tree return_type, tree access_path,
2211 tree conversion_path, int flags, tree obj,
2212 unification_kind_t strict)
2214 int ntparms = DECL_NTPARMS (tmpl);
2215 tree targs = make_tree_vec (ntparms);
2216 tree args_without_in_chrg = arglist;
2217 struct z_candidate *cand;
2221 /* We don't do deduction on the in-charge parameter, the VTT
2222 parameter or 'this'. */
2223 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2224 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2226 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2227 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2228 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2229 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2231 i = fn_type_unification (tmpl, explicit_targs, targs,
2232 args_without_in_chrg,
2233 return_type, strict, flags);
2238 fn = instantiate_template (tmpl, targs, tf_none);
2239 if (fn == error_mark_node)
2244 A member function template is never instantiated to perform the
2245 copy of a class object to an object of its class type.
2247 It's a little unclear what this means; the standard explicitly
2248 does allow a template to be used to copy a class. For example,
2253 template <class T> A(const T&);
2256 void g () { A a (f ()); }
2258 the member template will be used to make the copy. The section
2259 quoted above appears in the paragraph that forbids constructors
2260 whose only parameter is (a possibly cv-qualified variant of) the
2261 class type, and a logical interpretation is that the intent was
2262 to forbid the instantiation of member templates which would then
2264 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2266 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2267 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2272 if (obj != NULL_TREE)
2273 /* Aha, this is a conversion function. */
2274 cand = add_conv_candidate (candidates, fn, obj, access_path,
2275 conversion_path, arglist);
2277 cand = add_function_candidate (candidates, fn, ctype,
2278 arglist, access_path,
2279 conversion_path, flags);
2280 if (DECL_TI_TEMPLATE (fn) != tmpl)
2281 /* This situation can occur if a member template of a template
2282 class is specialized. Then, instantiate_template might return
2283 an instantiation of the specialization, in which case the
2284 DECL_TI_TEMPLATE field will point at the original
2285 specialization. For example:
2287 template <class T> struct S { template <class U> void f(U);
2288 template <> void f(int) {}; };
2292 Here, TMPL will be template <class U> S<double>::f(U).
2293 And, instantiate template will give us the specialization
2294 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2295 for this will point at template <class T> template <> S<T>::f(int),
2296 so that we can find the definition. For the purposes of
2297 overload resolution, however, we want the original TMPL. */
2298 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2300 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2306 static struct z_candidate *
2307 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2308 tree explicit_targs, tree arglist, tree return_type,
2309 tree access_path, tree conversion_path, int flags,
2310 unification_kind_t strict)
2313 add_template_candidate_real (candidates, tmpl, ctype,
2314 explicit_targs, arglist, return_type,
2315 access_path, conversion_path,
2316 flags, NULL_TREE, strict);
2320 static struct z_candidate *
2321 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2322 tree obj, tree arglist, tree return_type,
2323 tree access_path, tree conversion_path)
2326 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2327 arglist, return_type, access_path,
2328 conversion_path, 0, obj, DEDUCE_CONV);
2331 /* The CANDS are the set of candidates that were considered for
2332 overload resolution. Return the set of viable candidates. If none
2333 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2334 is true if a candidate should be considered viable only if it is
2337 static struct z_candidate*
2338 splice_viable (struct z_candidate *cands,
2342 struct z_candidate *viable;
2343 struct z_candidate **last_viable;
2344 struct z_candidate **cand;
2347 last_viable = &viable;
2348 *any_viable_p = false;
2353 struct z_candidate *c = *cand;
2354 if (strict_p ? c->viable == 1 : c->viable)
2359 last_viable = &c->next;
2360 *any_viable_p = true;
2366 return viable ? viable : cands;
2370 any_strictly_viable (struct z_candidate *cands)
2372 for (; cands; cands = cands->next)
2373 if (cands->viable == 1)
2378 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2379 words, it is about to become the "this" pointer for a member
2380 function call. Take the address of the object. */
2383 build_this (tree obj)
2385 /* In a template, we are only concerned about the type of the
2386 expression, so we can take a shortcut. */
2387 if (processing_template_decl)
2388 return build_address (obj);
2390 return build_unary_op (ADDR_EXPR, obj, 0);
2393 /* Returns true iff functions are equivalent. Equivalent functions are
2394 not '==' only if one is a function-local extern function or if
2395 both are extern "C". */
2398 equal_functions (tree fn1, tree fn2)
2400 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2401 || DECL_EXTERN_C_FUNCTION_P (fn1))
2402 return decls_match (fn1, fn2);
2406 /* Print information about one overload candidate CANDIDATE. MSGSTR
2407 is the text to print before the candidate itself.
2409 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2410 to have been run through gettext by the caller. This wart makes
2411 life simpler in print_z_candidates and for the translators. */
2414 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2416 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2418 if (candidate->num_convs == 3)
2419 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2420 candidate->convs[0]->type,
2421 candidate->convs[1]->type,
2422 candidate->convs[2]->type);
2423 else if (candidate->num_convs == 2)
2424 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2425 candidate->convs[0]->type,
2426 candidate->convs[1]->type);
2428 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2429 candidate->convs[0]->type);
2431 else if (TYPE_P (candidate->fn))
2432 inform ("%s %T <conversion>", msgstr, candidate->fn);
2433 else if (candidate->viable == -1)
2434 inform ("%s %+#D <near match>", msgstr, candidate->fn);
2436 inform ("%s %+#D", msgstr, candidate->fn);
2440 print_z_candidates (struct z_candidate *candidates)
2443 struct z_candidate *cand1;
2444 struct z_candidate **cand2;
2446 /* There may be duplicates in the set of candidates. We put off
2447 checking this condition as long as possible, since we have no way
2448 to eliminate duplicates from a set of functions in less than n^2
2449 time. Now we are about to emit an error message, so it is more
2450 permissible to go slowly. */
2451 for (cand1 = candidates; cand1; cand1 = cand1->next)
2453 tree fn = cand1->fn;
2454 /* Skip builtin candidates and conversion functions. */
2455 if (TREE_CODE (fn) != FUNCTION_DECL)
2457 cand2 = &cand1->next;
2460 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2461 && equal_functions (fn, (*cand2)->fn))
2462 *cand2 = (*cand2)->next;
2464 cand2 = &(*cand2)->next;
2471 str = _("candidates are:");
2472 print_z_candidate (str, candidates);
2473 if (candidates->next)
2475 /* Indent successive candidates by the width of the translation
2476 of the above string. */
2477 size_t len = gcc_gettext_width (str) + 1;
2478 char *spaces = (char *) alloca (len);
2479 memset (spaces, ' ', len-1);
2480 spaces[len - 1] = '\0';
2482 candidates = candidates->next;
2485 print_z_candidate (spaces, candidates);
2486 candidates = candidates->next;
2492 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2493 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2494 the result of the conversion function to convert it to the final
2495 desired type. Merge the two sequences into a single sequence,
2496 and return the merged sequence. */
2499 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2503 gcc_assert (user_seq->kind == ck_user);
2505 /* Find the end of the second conversion sequence. */
2507 while ((*t)->kind != ck_identity)
2508 t = &((*t)->u.next);
2510 /* Replace the identity conversion with the user conversion
2514 /* The entire sequence is a user-conversion sequence. */
2515 std_seq->user_conv_p = true;
2520 /* Returns the best overload candidate to perform the requested
2521 conversion. This function is used for three the overloading situations
2522 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2523 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2524 per [dcl.init.ref], so we ignore temporary bindings. */
2526 static struct z_candidate *
2527 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2529 struct z_candidate *candidates, *cand;
2530 tree fromtype = TREE_TYPE (expr);
2531 tree ctors = NULL_TREE;
2532 tree conv_fns = NULL_TREE;
2533 conversion *conv = NULL;
2534 tree args = NULL_TREE;
2537 /* We represent conversion within a hierarchy using RVALUE_CONV and
2538 BASE_CONV, as specified by [over.best.ics]; these become plain
2539 constructor calls, as specified in [dcl.init]. */
2540 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2541 || !DERIVED_FROM_P (totype, fromtype));
2543 if (IS_AGGR_TYPE (totype))
2544 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2546 if (IS_AGGR_TYPE (fromtype))
2547 conv_fns = lookup_conversions (fromtype);
2550 flags |= LOOKUP_NO_CONVERSION;
2556 ctors = BASELINK_FUNCTIONS (ctors);
2558 t = build_int_cst (build_pointer_type (totype), 0);
2559 args = build_tree_list (NULL_TREE, expr);
2560 /* We should never try to call the abstract or base constructor
2562 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2563 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2564 args = tree_cons (NULL_TREE, t, args);
2566 for (; ctors; ctors = OVL_NEXT (ctors))
2568 tree ctor = OVL_CURRENT (ctors);
2569 if (DECL_NONCONVERTING_P (ctor))
2572 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2573 cand = add_template_candidate (&candidates, ctor, totype,
2574 NULL_TREE, args, NULL_TREE,
2575 TYPE_BINFO (totype),
2576 TYPE_BINFO (totype),
2580 cand = add_function_candidate (&candidates, ctor, totype,
2581 args, TYPE_BINFO (totype),
2582 TYPE_BINFO (totype),
2586 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2590 args = build_tree_list (NULL_TREE, build_this (expr));
2592 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2595 tree conversion_path = TREE_PURPOSE (conv_fns);
2596 int convflags = LOOKUP_NO_CONVERSION;
2598 /* If we are called to convert to a reference type, we are trying to
2599 find an lvalue binding, so don't even consider temporaries. If
2600 we don't find an lvalue binding, the caller will try again to
2601 look for a temporary binding. */
2602 if (TREE_CODE (totype) == REFERENCE_TYPE)
2603 convflags |= LOOKUP_NO_TEMP_BIND;
2605 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2607 tree fn = OVL_CURRENT (fns);
2609 /* [over.match.funcs] For conversion functions, the function
2610 is considered to be a member of the class of the implicit
2611 object argument for the purpose of defining the type of
2612 the implicit object parameter.
2614 So we pass fromtype as CTYPE to add_*_candidate. */
2616 if (TREE_CODE (fn) == TEMPLATE_DECL)
2617 cand = add_template_candidate (&candidates, fn, fromtype,
2620 TYPE_BINFO (fromtype),
2625 cand = add_function_candidate (&candidates, fn, fromtype,
2627 TYPE_BINFO (fromtype),
2634 = implicit_conversion (totype,
2635 TREE_TYPE (TREE_TYPE (cand->fn)),
2637 /*c_cast_p=*/false, convflags);
2639 cand->second_conv = ics;
2643 else if (candidates->viable == 1 && ics->bad_p)
2649 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2653 cand = tourney (candidates);
2656 if (flags & LOOKUP_COMPLAIN)
2658 error ("conversion from %qT to %qT is ambiguous",
2660 print_z_candidates (candidates);
2663 cand = candidates; /* any one will do */
2664 cand->second_conv = build_ambiguous_conv (totype, expr);
2665 cand->second_conv->user_conv_p = true;
2666 if (!any_strictly_viable (candidates))
2667 cand->second_conv->bad_p = true;
2668 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2669 ambiguous conversion is no worse than another user-defined
2675 /* Build the user conversion sequence. */
2678 (DECL_CONSTRUCTOR_P (cand->fn)
2679 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2680 build_identity_conv (TREE_TYPE (expr), expr));
2683 /* Combine it with the second conversion sequence. */
2684 cand->second_conv = merge_conversion_sequences (conv,
2687 if (cand->viable == -1)
2688 cand->second_conv->bad_p = true;
2694 build_user_type_conversion (tree totype, tree expr, int flags)
2696 struct z_candidate *cand
2697 = build_user_type_conversion_1 (totype, expr, flags);
2701 if (cand->second_conv->kind == ck_ambig)
2702 return error_mark_node;
2703 expr = convert_like (cand->second_conv, expr);
2704 return convert_from_reference (expr);
2709 /* Do any initial processing on the arguments to a function call. */
2712 resolve_args (tree args)
2715 for (t = args; t; t = TREE_CHAIN (t))
2717 tree arg = TREE_VALUE (t);
2719 if (error_operand_p (arg))
2720 return error_mark_node;
2721 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2723 error ("invalid use of void expression");
2724 return error_mark_node;
2726 else if (invalid_nonstatic_memfn_p (arg))
2727 return error_mark_node;
2732 /* Perform overload resolution on FN, which is called with the ARGS.
2734 Return the candidate function selected by overload resolution, or
2735 NULL if the event that overload resolution failed. In the case
2736 that overload resolution fails, *CANDIDATES will be the set of
2737 candidates considered, and ANY_VIABLE_P will be set to true or
2738 false to indicate whether or not any of the candidates were
2741 The ARGS should already have gone through RESOLVE_ARGS before this
2742 function is called. */
2744 static struct z_candidate *
2745 perform_overload_resolution (tree fn,
2747 struct z_candidate **candidates,
2750 struct z_candidate *cand;
2751 tree explicit_targs = NULL_TREE;
2752 int template_only = 0;
2755 *any_viable_p = true;
2757 /* Check FN and ARGS. */
2758 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2759 || TREE_CODE (fn) == TEMPLATE_DECL
2760 || TREE_CODE (fn) == OVERLOAD
2761 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2762 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2764 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2766 explicit_targs = TREE_OPERAND (fn, 1);
2767 fn = TREE_OPERAND (fn, 0);
2771 /* Add the various candidate functions. */
2772 add_candidates (fn, args, explicit_targs, template_only,
2773 /*conversion_path=*/NULL_TREE,
2774 /*access_path=*/NULL_TREE,
2778 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2782 cand = tourney (*candidates);
2786 /* Return an expression for a call to FN (a namespace-scope function,
2787 or a static member function) with the ARGS. */
2790 build_new_function_call (tree fn, tree args, bool koenig_p)
2792 struct z_candidate *candidates, *cand;
2797 args = resolve_args (args);
2798 if (args == error_mark_node)
2799 return error_mark_node;
2801 /* If this function was found without using argument dependent
2802 lookup, then we want to ignore any undeclared friend
2808 fn = remove_hidden_names (fn);
2811 error ("no matching function for call to %<%D(%A)%>",
2812 DECL_NAME (OVL_CURRENT (orig_fn)), args);
2813 return error_mark_node;
2817 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2818 p = conversion_obstack_alloc (0);
2820 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2824 if (!any_viable_p && candidates && ! candidates->next)
2825 return build_function_call (candidates->fn, args);
2826 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2827 fn = TREE_OPERAND (fn, 0);
2829 error ("no matching function for call to %<%D(%A)%>",
2830 DECL_NAME (OVL_CURRENT (fn)), args);
2832 error ("call of overloaded %<%D(%A)%> is ambiguous",
2833 DECL_NAME (OVL_CURRENT (fn)), args);
2835 print_z_candidates (candidates);
2836 result = error_mark_node;
2839 result = build_over_call (cand, LOOKUP_NORMAL);
2841 /* Free all the conversions we allocated. */
2842 obstack_free (&conversion_obstack, p);
2847 /* Build a call to a global operator new. FNNAME is the name of the
2848 operator (either "operator new" or "operator new[]") and ARGS are
2849 the arguments provided. *SIZE points to the total number of bytes
2850 required by the allocation, and is updated if that is changed here.
2851 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2852 function determines that no cookie should be used, after all,
2853 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2854 set, upon return, to the allocation function called. */
2857 build_operator_new_call (tree fnname, tree args,
2858 tree *size, tree *cookie_size,
2862 struct z_candidate *candidates;
2863 struct z_candidate *cand;
2868 args = tree_cons (NULL_TREE, *size, args);
2869 args = resolve_args (args);
2870 if (args == error_mark_node)
2877 If this lookup fails to find the name, or if the allocated type
2878 is not a class type, the allocation function's name is looked
2879 up in the global scope.
2881 we disregard block-scope declarations of "operator new". */
2882 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2884 /* Figure out what function is being called. */
2885 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2887 /* If no suitable function could be found, issue an error message
2892 error ("no matching function for call to %<%D(%A)%>",
2893 DECL_NAME (OVL_CURRENT (fns)), args);
2895 error ("call of overloaded %<%D(%A)%> is ambiguous",
2896 DECL_NAME (OVL_CURRENT (fns)), args);
2898 print_z_candidates (candidates);
2899 return error_mark_node;
2902 /* If a cookie is required, add some extra space. Whether
2903 or not a cookie is required cannot be determined until
2904 after we know which function was called. */
2907 bool use_cookie = true;
2908 if (!abi_version_at_least (2))
2910 tree placement = TREE_CHAIN (args);
2911 /* In G++ 3.2, the check was implemented incorrectly; it
2912 looked at the placement expression, rather than the
2913 type of the function. */
2914 if (placement && !TREE_CHAIN (placement)
2915 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2923 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2924 /* Skip the size_t parameter. */
2925 arg_types = TREE_CHAIN (arg_types);
2926 /* Check the remaining parameters (if any). */
2928 && TREE_CHAIN (arg_types) == void_list_node
2929 && same_type_p (TREE_VALUE (arg_types),
2933 /* If we need a cookie, adjust the number of bytes allocated. */
2936 /* Update the total size. */
2937 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2938 /* Update the argument list to reflect the adjusted size. */
2939 TREE_VALUE (args) = *size;
2942 *cookie_size = NULL_TREE;
2945 /* Tell our caller which function we decided to call. */
2949 /* Build the CALL_EXPR. */
2950 return build_over_call (cand, LOOKUP_NORMAL);
2954 build_object_call (tree obj, tree args)
2956 struct z_candidate *candidates = 0, *cand;
2957 tree fns, convs, mem_args = NULL_TREE;
2958 tree type = TREE_TYPE (obj);
2960 tree result = NULL_TREE;
2963 if (TYPE_PTRMEMFUNC_P (type))
2965 /* It's no good looking for an overloaded operator() on a
2966 pointer-to-member-function. */
2967 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
2968 return error_mark_node;
2971 if (TYPE_BINFO (type))
2973 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
2974 if (fns == error_mark_node)
2975 return error_mark_node;
2980 args = resolve_args (args);
2982 if (args == error_mark_node)
2983 return error_mark_node;
2985 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2986 p = conversion_obstack_alloc (0);
2990 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
2991 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
2993 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
2995 tree fn = OVL_CURRENT (fns);
2996 if (TREE_CODE (fn) == TEMPLATE_DECL)
2997 add_template_candidate (&candidates, fn, base, NULL_TREE,
2998 mem_args, NULL_TREE,
3001 LOOKUP_NORMAL, DEDUCE_CALL);
3003 add_function_candidate
3004 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3005 TYPE_BINFO (type), LOOKUP_NORMAL);
3009 convs = lookup_conversions (type);
3011 for (; convs; convs = TREE_CHAIN (convs))
3013 tree fns = TREE_VALUE (convs);
3014 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3016 if ((TREE_CODE (totype) == POINTER_TYPE
3017 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3018 || (TREE_CODE (totype) == REFERENCE_TYPE
3019 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3020 || (TREE_CODE (totype) == REFERENCE_TYPE
3021 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3022 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3023 for (; fns; fns = OVL_NEXT (fns))
3025 tree fn = OVL_CURRENT (fns);
3026 if (TREE_CODE (fn) == TEMPLATE_DECL)
3027 add_template_conv_candidate
3028 (&candidates, fn, obj, args, totype,
3029 /*access_path=*/NULL_TREE,
3030 /*conversion_path=*/NULL_TREE);
3032 add_conv_candidate (&candidates, fn, obj, args,
3033 /*conversion_path=*/NULL_TREE,
3034 /*access_path=*/NULL_TREE);
3038 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3041 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3042 print_z_candidates (candidates);
3043 result = error_mark_node;
3047 cand = tourney (candidates);
3050 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
3051 print_z_candidates (candidates);
3052 result = error_mark_node;
3054 /* Since cand->fn will be a type, not a function, for a conversion
3055 function, we must be careful not to unconditionally look at
3057 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3058 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3059 result = build_over_call (cand, LOOKUP_NORMAL);
3062 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
3063 obj = convert_from_reference (obj);
3064 result = build_function_call (obj, args);
3068 /* Free all the conversions we allocated. */
3069 obstack_free (&conversion_obstack, p);
3075 op_error (enum tree_code code, enum tree_code code2,
3076 tree arg1, tree arg2, tree arg3, const char *problem)
3080 if (code == MODIFY_EXPR)
3081 opname = assignment_operator_name_info[code2].name;
3083 opname = operator_name_info[code].name;
3088 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3089 problem, arg1, arg2, arg3);
3092 case POSTINCREMENT_EXPR:
3093 case POSTDECREMENT_EXPR:
3094 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3098 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3103 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3108 error ("%s for %<operator%s%> in %<%E %s %E%>",
3109 problem, opname, arg1, opname, arg2);
3111 error ("%s for %<operator%s%> in %<%s%E%>",
3112 problem, opname, opname, arg1);
3117 /* Return the implicit conversion sequence that could be used to
3118 convert E1 to E2 in [expr.cond]. */
3121 conditional_conversion (tree e1, tree e2)
3123 tree t1 = non_reference (TREE_TYPE (e1));
3124 tree t2 = non_reference (TREE_TYPE (e2));
3130 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3131 implicitly converted (clause _conv_) to the type "reference to
3132 T2", subject to the constraint that in the conversion the
3133 reference must bind directly (_dcl.init.ref_) to E1. */
3134 if (real_lvalue_p (e2))
3136 conv = implicit_conversion (build_reference_type (t2),
3140 LOOKUP_NO_TEMP_BIND);
3147 If E1 and E2 have class type, and the underlying class types are
3148 the same or one is a base class of the other: E1 can be converted
3149 to match E2 if the class of T2 is the same type as, or a base
3150 class of, the class of T1, and the cv-qualification of T2 is the
3151 same cv-qualification as, or a greater cv-qualification than, the
3152 cv-qualification of T1. If the conversion is applied, E1 is
3153 changed to an rvalue of type T2 that still refers to the original
3154 source class object (or the appropriate subobject thereof). */
3155 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3156 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3158 if (good_base && at_least_as_qualified_p (t2, t1))
3160 conv = build_identity_conv (t1, e1);
3161 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3162 TYPE_MAIN_VARIANT (t2)))
3163 conv = build_conv (ck_base, t2, conv);
3165 conv = build_conv (ck_rvalue, t2, conv);
3174 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3175 converted to the type that expression E2 would have if E2 were
3176 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3177 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3181 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3182 arguments to the conditional expression. */
3185 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3189 tree result = NULL_TREE;
3190 tree result_type = NULL_TREE;
3191 bool lvalue_p = true;
3192 struct z_candidate *candidates = 0;
3193 struct z_candidate *cand;
3196 /* As a G++ extension, the second argument to the conditional can be
3197 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3198 c'.) If the second operand is omitted, make sure it is
3199 calculated only once. */
3203 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3205 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3206 if (real_lvalue_p (arg1))
3207 arg2 = arg1 = stabilize_reference (arg1);
3209 arg2 = arg1 = save_expr (arg1);
3214 The first expr ession is implicitly converted to bool (clause
3216 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3218 /* If something has already gone wrong, just pass that fact up the
3220 if (error_operand_p (arg1)
3221 || error_operand_p (arg2)
3222 || error_operand_p (arg3))
3223 return error_mark_node;
3227 If either the second or the third operand has type (possibly
3228 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3229 array-to-pointer (_conv.array_), and function-to-pointer
3230 (_conv.func_) standard conversions are performed on the second
3231 and third operands. */
3232 arg2_type = is_bitfield_expr_with_lowered_type (arg2);
3234 arg2_type = TREE_TYPE (arg2);
3235 arg3_type = is_bitfield_expr_with_lowered_type (arg3);
3237 arg3_type = TREE_TYPE (arg3);
3238 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3240 /* Do the conversions. We don't these for `void' type arguments
3241 since it can't have any effect and since decay_conversion
3242 does not handle that case gracefully. */
3243 if (!VOID_TYPE_P (arg2_type))
3244 arg2 = decay_conversion (arg2);
3245 if (!VOID_TYPE_P (arg3_type))
3246 arg3 = decay_conversion (arg3);
3247 arg2_type = TREE_TYPE (arg2);
3248 arg3_type = TREE_TYPE (arg3);
3252 One of the following shall hold:
3254 --The second or the third operand (but not both) is a
3255 throw-expression (_except.throw_); the result is of the
3256 type of the other and is an rvalue.
3258 --Both the second and the third operands have type void; the
3259 result is of type void and is an rvalue.
3261 We must avoid calling force_rvalue for expressions of type
3262 "void" because it will complain that their value is being
3264 if (TREE_CODE (arg2) == THROW_EXPR
3265 && TREE_CODE (arg3) != THROW_EXPR)
3267 if (!VOID_TYPE_P (arg3_type))
3268 arg3 = force_rvalue (arg3);
3269 arg3_type = TREE_TYPE (arg3);
3270 result_type = arg3_type;
3272 else if (TREE_CODE (arg2) != THROW_EXPR
3273 && TREE_CODE (arg3) == THROW_EXPR)
3275 if (!VOID_TYPE_P (arg2_type))
3276 arg2 = force_rvalue (arg2);
3277 arg2_type = TREE_TYPE (arg2);
3278 result_type = arg2_type;
3280 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3281 result_type = void_type_node;
3284 error ("%qE has type %<void%> and is not a throw-expression",
3285 VOID_TYPE_P (arg2_type) ? arg2 : arg3);
3286 return error_mark_node;
3290 goto valid_operands;
3294 Otherwise, if the second and third operand have different types,
3295 and either has (possibly cv-qualified) class type, an attempt is
3296 made to convert each of those operands to the type of the other. */
3297 else if (!same_type_p (arg2_type, arg3_type)
3298 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3303 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3304 p = conversion_obstack_alloc (0);
3306 conv2 = conditional_conversion (arg2, arg3);
3307 conv3 = conditional_conversion (arg3, arg2);
3311 If both can be converted, or one can be converted but the
3312 conversion is ambiguous, the program is ill-formed. If
3313 neither can be converted, the operands are left unchanged and
3314 further checking is performed as described below. If exactly
3315 one conversion is possible, that conversion is applied to the
3316 chosen operand and the converted operand is used in place of
3317 the original operand for the remainder of this section. */
3318 if ((conv2 && !conv2->bad_p
3319 && conv3 && !conv3->bad_p)
3320 || (conv2 && conv2->kind == ck_ambig)
3321 || (conv3 && conv3->kind == ck_ambig))
3323 error ("operands to ?: have different types %qT and %qT",
3324 arg2_type, arg3_type);
3325 result = error_mark_node;
3327 else if (conv2 && (!conv2->bad_p || !conv3))
3329 arg2 = convert_like (conv2, arg2);
3330 arg2 = convert_from_reference (arg2);
3331 arg2_type = TREE_TYPE (arg2);
3332 /* Even if CONV2 is a valid conversion, the result of the
3333 conversion may be invalid. For example, if ARG3 has type
3334 "volatile X", and X does not have a copy constructor
3335 accepting a "volatile X&", then even if ARG2 can be
3336 converted to X, the conversion will fail. */
3337 if (error_operand_p (arg2))
3338 result = error_mark_node;
3340 else if (conv3 && (!conv3->bad_p || !conv2))
3342 arg3 = convert_like (conv3, arg3);
3343 arg3 = convert_from_reference (arg3);
3344 arg3_type = TREE_TYPE (arg3);
3345 if (error_operand_p (arg3))
3346 result = error_mark_node;
3349 /* Free all the conversions we allocated. */
3350 obstack_free (&conversion_obstack, p);
3355 /* If, after the conversion, both operands have class type,
3356 treat the cv-qualification of both operands as if it were the
3357 union of the cv-qualification of the operands.
3359 The standard is not clear about what to do in this
3360 circumstance. For example, if the first operand has type
3361 "const X" and the second operand has a user-defined
3362 conversion to "volatile X", what is the type of the second
3363 operand after this step? Making it be "const X" (matching
3364 the first operand) seems wrong, as that discards the
3365 qualification without actually performing a copy. Leaving it
3366 as "volatile X" seems wrong as that will result in the
3367 conditional expression failing altogether, even though,
3368 according to this step, the one operand could be converted to
3369 the type of the other. */
3370 if ((conv2 || conv3)
3371 && CLASS_TYPE_P (arg2_type)
3372 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3373 arg2_type = arg3_type =
3374 cp_build_qualified_type (arg2_type,
3375 TYPE_QUALS (arg2_type)
3376 | TYPE_QUALS (arg3_type));
3381 If the second and third operands are lvalues and have the same
3382 type, the result is of that type and is an lvalue. */
3383 if (real_lvalue_p (arg2)
3384 && real_lvalue_p (arg3)
3385 && same_type_p (arg2_type, arg3_type))
3387 result_type = arg2_type;
3388 goto valid_operands;
3393 Otherwise, the result is an rvalue. If the second and third
3394 operand do not have the same type, and either has (possibly
3395 cv-qualified) class type, overload resolution is used to
3396 determine the conversions (if any) to be applied to the operands
3397 (_over.match.oper_, _over.built_). */
3399 if (!same_type_p (arg2_type, arg3_type)
3400 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3406 /* Rearrange the arguments so that add_builtin_candidate only has
3407 to know about two args. In build_builtin_candidates, the
3408 arguments are unscrambled. */
3412 add_builtin_candidates (&candidates,
3415 ansi_opname (COND_EXPR),
3421 If the overload resolution fails, the program is
3423 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3426 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3427 print_z_candidates (candidates);
3428 return error_mark_node;
3430 cand = tourney (candidates);
3433 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3434 print_z_candidates (candidates);
3435 return error_mark_node;
3440 Otherwise, the conversions thus determined are applied, and
3441 the converted operands are used in place of the original
3442 operands for the remainder of this section. */
3443 conv = cand->convs[0];
3444 arg1 = convert_like (conv, arg1);
3445 conv = cand->convs[1];
3446 arg2 = convert_like (conv, arg2);
3447 conv = cand->convs[2];
3448 arg3 = convert_like (conv, arg3);
3453 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3454 and function-to-pointer (_conv.func_) standard conversions are
3455 performed on the second and third operands.
3457 We need to force the lvalue-to-rvalue conversion here for class types,
3458 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3459 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3462 arg2 = force_rvalue (arg2);
3463 if (!CLASS_TYPE_P (arg2_type))
3464 arg2_type = TREE_TYPE (arg2);
3466 arg3 = force_rvalue (arg3);
3467 if (!CLASS_TYPE_P (arg2_type))
3468 arg3_type = TREE_TYPE (arg3);
3470 if (arg2 == error_mark_node || arg3 == error_mark_node)
3471 return error_mark_node;
3475 After those conversions, one of the following shall hold:
3477 --The second and third operands have the same type; the result is of
3479 if (same_type_p (arg2_type, arg3_type))
3480 result_type = arg2_type;
3483 --The second and third operands have arithmetic or enumeration
3484 type; the usual arithmetic conversions are performed to bring
3485 them to a common type, and the result is of that type. */
3486 else if ((ARITHMETIC_TYPE_P (arg2_type)
3487 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3488 && (ARITHMETIC_TYPE_P (arg3_type)
3489 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3491 /* In this case, there is always a common type. */
3492 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3495 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3496 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3497 warning (0, "enumeral mismatch in conditional expression: %qT vs %qT",
3498 arg2_type, arg3_type);
3499 else if (extra_warnings
3500 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3501 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3502 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3503 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3504 warning (0, "enumeral and non-enumeral type in conditional expression");
3506 arg2 = perform_implicit_conversion (result_type, arg2);
3507 arg3 = perform_implicit_conversion (result_type, arg3);
3511 --The second and third operands have pointer type, or one has
3512 pointer type and the other is a null pointer constant; pointer
3513 conversions (_conv.ptr_) and qualification conversions
3514 (_conv.qual_) are performed to bring them to their composite
3515 pointer type (_expr.rel_). The result is of the composite
3518 --The second and third operands have pointer to member type, or
3519 one has pointer to member type and the other is a null pointer
3520 constant; pointer to member conversions (_conv.mem_) and
3521 qualification conversions (_conv.qual_) are performed to bring
3522 them to a common type, whose cv-qualification shall match the
3523 cv-qualification of either the second or the third operand.
3524 The result is of the common type. */
3525 else if ((null_ptr_cst_p (arg2)
3526 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3527 || (null_ptr_cst_p (arg3)
3528 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3529 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3530 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3531 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3533 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3534 arg3, "conditional expression");
3535 if (result_type == error_mark_node)
3536 return error_mark_node;
3537 arg2 = perform_implicit_conversion (result_type, arg2);
3538 arg3 = perform_implicit_conversion (result_type, arg3);
3543 error ("operands to ?: have different types %qT and %qT",
3544 arg2_type, arg3_type);
3545 return error_mark_node;
3549 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3551 /* We can't use result_type below, as fold might have returned a
3556 /* Expand both sides into the same slot, hopefully the target of
3557 the ?: expression. We used to check for TARGET_EXPRs here,
3558 but now we sometimes wrap them in NOP_EXPRs so the test would
3560 if (CLASS_TYPE_P (TREE_TYPE (result)))
3561 result = get_target_expr (result);
3562 /* If this expression is an rvalue, but might be mistaken for an
3563 lvalue, we must add a NON_LVALUE_EXPR. */
3564 result = rvalue (result);
3570 /* OPERAND is an operand to an expression. Perform necessary steps
3571 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3575 prep_operand (tree operand)
3579 if (CLASS_TYPE_P (TREE_TYPE (operand))
3580 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3581 /* Make sure the template type is instantiated now. */
3582 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3588 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3589 OVERLOAD) to the CANDIDATES, returning an updated list of
3590 CANDIDATES. The ARGS are the arguments provided to the call,
3591 without any implicit object parameter. The EXPLICIT_TARGS are
3592 explicit template arguments provided. TEMPLATE_ONLY is true if
3593 only template functions should be considered. CONVERSION_PATH,
3594 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3597 add_candidates (tree fns, tree args,
3598 tree explicit_targs, bool template_only,
3599 tree conversion_path, tree access_path,
3601 struct z_candidate **candidates)
3604 tree non_static_args;
3606 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3607 /* Delay creating the implicit this parameter until it is needed. */
3608 non_static_args = NULL_TREE;
3615 fn = OVL_CURRENT (fns);
3616 /* Figure out which set of arguments to use. */
3617 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3619 /* If this function is a non-static member, prepend the implicit
3620 object parameter. */
3621 if (!non_static_args)
3622 non_static_args = tree_cons (NULL_TREE,
3623 build_this (TREE_VALUE (args)),
3625 fn_args = non_static_args;
3628 /* Otherwise, just use the list of arguments provided. */
3631 if (TREE_CODE (fn) == TEMPLATE_DECL)
3632 add_template_candidate (candidates,
3642 else if (!template_only)
3643 add_function_candidate (candidates,
3650 fns = OVL_NEXT (fns);
3655 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3658 struct z_candidate *candidates = 0, *cand;
3659 tree arglist, fnname;
3661 tree result = NULL_TREE;
3662 bool result_valid_p = false;
3663 enum tree_code code2 = NOP_EXPR;
3669 if (error_operand_p (arg1)
3670 || error_operand_p (arg2)
3671 || error_operand_p (arg3))
3672 return error_mark_node;
3674 if (code == MODIFY_EXPR)
3676 code2 = TREE_CODE (arg3);
3678 fnname = ansi_assopname (code2);
3681 fnname = ansi_opname (code);
3683 arg1 = prep_operand (arg1);
3689 case VEC_DELETE_EXPR:
3691 /* Use build_op_new_call and build_op_delete_call instead. */
3695 return build_object_call (arg1, arg2);
3701 arg2 = prep_operand (arg2);
3702 arg3 = prep_operand (arg3);
3704 if (code == COND_EXPR)
3706 if (arg2 == NULL_TREE
3707 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3708 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3709 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3710 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3713 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3714 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3717 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3718 arg2 = integer_zero_node;
3720 arglist = NULL_TREE;
3722 arglist = tree_cons (NULL_TREE, arg3, arglist);
3724 arglist = tree_cons (NULL_TREE, arg2, arglist);
3725 arglist = tree_cons (NULL_TREE, arg1, arglist);
3727 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3728 p = conversion_obstack_alloc (0);
3730 /* Add namespace-scope operators to the list of functions to
3732 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3733 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3734 flags, &candidates);
3735 /* Add class-member operators to the candidate set. */
3736 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3740 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3741 if (fns == error_mark_node)
3743 result = error_mark_node;
3744 goto user_defined_result_ready;
3747 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3749 BASELINK_BINFO (fns),
3750 TYPE_BINFO (TREE_TYPE (arg1)),
3751 flags, &candidates);
3754 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3755 to know about two args; a builtin candidate will always have a first
3756 parameter of type bool. We'll handle that in
3757 build_builtin_candidate. */
3758 if (code == COND_EXPR)
3768 args[2] = NULL_TREE;
3771 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3777 /* For these, the built-in candidates set is empty
3778 [over.match.oper]/3. We don't want non-strict matches
3779 because exact matches are always possible with built-in
3780 operators. The built-in candidate set for COMPONENT_REF
3781 would be empty too, but since there are no such built-in
3782 operators, we accept non-strict matches for them. */
3787 strict_p = pedantic;
3791 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3796 case POSTINCREMENT_EXPR:
3797 case POSTDECREMENT_EXPR:
3798 /* Look for an `operator++ (int)'. If they didn't have
3799 one, then we fall back to the old way of doing things. */
3800 if (flags & LOOKUP_COMPLAIN)
3801 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3802 "trying prefix operator instead",
3804 operator_name_info[code].name);
3805 if (code == POSTINCREMENT_EXPR)
3806 code = PREINCREMENT_EXPR;
3808 code = PREDECREMENT_EXPR;
3809 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3813 /* The caller will deal with these. */
3818 result_valid_p = true;
3822 if (flags & LOOKUP_COMPLAIN)
3824 op_error (code, code2, arg1, arg2, arg3, "no match");
3825 print_z_candidates (candidates);
3827 result = error_mark_node;
3833 cand = tourney (candidates);
3836 if (flags & LOOKUP_COMPLAIN)
3838 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3839 print_z_candidates (candidates);
3841 result = error_mark_node;
3843 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3846 *overloaded_p = true;
3848 result = build_over_call (cand, LOOKUP_NORMAL);
3852 /* Give any warnings we noticed during overload resolution. */
3855 struct candidate_warning *w;
3856 for (w = cand->warnings; w; w = w->next)
3857 joust (cand, w->loser, 1);
3860 /* Check for comparison of different enum types. */
3869 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3870 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3871 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3872 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3874 warning (0, "comparison between %q#T and %q#T",
3875 TREE_TYPE (arg1), TREE_TYPE (arg2));
3882 /* We need to strip any leading REF_BIND so that bitfields
3883 don't cause errors. This should not remove any important
3884 conversions, because builtins don't apply to class
3885 objects directly. */
3886 conv = cand->convs[0];
3887 if (conv->kind == ck_ref_bind)
3888 conv = conv->u.next;
3889 arg1 = convert_like (conv, arg1);
3892 conv = cand->convs[1];
3893 if (conv->kind == ck_ref_bind)
3894 conv = conv->u.next;
3895 arg2 = convert_like (conv, arg2);
3899 conv = cand->convs[2];
3900 if (conv->kind == ck_ref_bind)
3901 conv = conv->u.next;
3902 arg3 = convert_like (conv, arg3);
3907 user_defined_result_ready:
3909 /* Free all the conversions we allocated. */
3910 obstack_free (&conversion_obstack, p);
3912 if (result || result_valid_p)
3919 return build_modify_expr (arg1, code2, arg2);
3922 return build_indirect_ref (arg1, "unary *");
3927 case TRUNC_DIV_EXPR:
3938 case TRUNC_MOD_EXPR:
3942 case TRUTH_ANDIF_EXPR:
3943 case TRUTH_ORIF_EXPR:
3944 return cp_build_binary_op (code, arg1, arg2);
3946 case UNARY_PLUS_EXPR:
3949 case TRUTH_NOT_EXPR:
3950 case PREINCREMENT_EXPR:
3951 case POSTINCREMENT_EXPR:
3952 case PREDECREMENT_EXPR:
3953 case POSTDECREMENT_EXPR:
3956 return build_unary_op (code, arg1, candidates != 0);
3959 return build_array_ref (arg1, arg2);
3962 return build_conditional_expr (arg1, arg2, arg3);
3965 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
3967 /* The caller will deal with these. */
3979 /* Build a call to operator delete. This has to be handled very specially,
3980 because the restrictions on what signatures match are different from all
3981 other call instances. For a normal delete, only a delete taking (void *)
3982 or (void *, size_t) is accepted. For a placement delete, only an exact
3983 match with the placement new is accepted.
3985 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
3986 ADDR is the pointer to be deleted.
3987 SIZE is the size of the memory block to be deleted.
3988 GLOBAL_P is true if the delete-expression should not consider
3989 class-specific delete operators.
3990 PLACEMENT is the corresponding placement new call, or NULL_TREE.
3991 If PLACEMENT is non-NULL, then ALLOC_FN is the allocation function
3992 called to perform the placement new. */
3995 build_op_delete_call (enum tree_code code, tree addr, tree size,
3996 bool global_p, tree placement,
3999 tree fn = NULL_TREE;
4000 tree fns, fnname, argtypes, args, type;
4003 if (addr == error_mark_node)
4004 return error_mark_node;
4006 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4008 fnname = ansi_opname (code);
4010 if (CLASS_TYPE_P (type)
4011 && COMPLETE_TYPE_P (complete_type (type))
4015 If the result of the lookup is ambiguous or inaccessible, or if
4016 the lookup selects a placement deallocation function, the
4017 program is ill-formed.
4019 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4021 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4022 if (fns == error_mark_node)
4023 return error_mark_node;
4028 if (fns == NULL_TREE)
4029 fns = lookup_name_nonclass (fnname);
4033 /* Get the parameter types for the allocation function that is
4035 gcc_assert (alloc_fn != NULL_TREE);
4036 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4037 /* Also the second argument. */
4038 args = TREE_CHAIN (TREE_OPERAND (placement, 1));
4042 /* First try it without the size argument. */
4043 argtypes = void_list_node;
4047 /* Strip const and volatile from addr. */
4048 addr = cp_convert (ptr_type_node, addr);
4050 /* We make two tries at finding a matching `operator delete'. On
4051 the first pass, we look for a one-operator (or placement)
4052 operator delete. If we're not doing placement delete, then on
4053 the second pass we look for a two-argument delete. */
4054 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4056 /* Go through the `operator delete' functions looking for one
4057 with a matching type. */
4058 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4064 /* The first argument must be "void *". */
4065 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4066 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4069 /* On the first pass, check the rest of the arguments. */
4075 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4083 /* On the second pass, the second argument must be
4086 && same_type_p (TREE_VALUE (t), size_type_node)
4087 && TREE_CHAIN (t) == void_list_node)
4091 /* If we found a match, we're done. */
4096 /* If we have a matching function, call it. */
4099 /* Make sure we have the actual function, and not an
4101 fn = OVL_CURRENT (fn);
4103 /* If the FN is a member function, make sure that it is
4105 if (DECL_CLASS_SCOPE_P (fn))
4106 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4109 args = tree_cons (NULL_TREE, addr, args);
4111 args = tree_cons (NULL_TREE, addr,
4112 build_tree_list (NULL_TREE, size));
4116 /* The placement args might not be suitable for overload
4117 resolution at this point, so build the call directly. */
4119 return build_cxx_call (fn, args);
4122 return build_function_call (fn, args);
4125 /* If we are doing placement delete we do nothing if we don't find a
4126 matching op delete. */
4130 error ("no suitable %<operator %s%> for %qT",
4131 operator_name_info[(int)code].name, type);
4132 return error_mark_node;
4135 /* If the current scope isn't allowed to access DECL along
4136 BASETYPE_PATH, give an error. The most derived class in
4137 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4138 the declaration to use in the error diagnostic. */
4141 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4143 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4145 if (!accessible_p (basetype_path, decl, true))
4147 if (TREE_PRIVATE (decl))
4148 error ("%q+#D is private", diag_decl);
4149 else if (TREE_PROTECTED (decl))
4150 error ("%q+#D is protected", diag_decl);
4152 error ("%q+#D is inaccessible", diag_decl);
4153 error ("within this context");
4160 /* Check that a callable constructor to initialize a temporary of
4161 TYPE from an EXPR exists. */
4164 check_constructor_callable (tree type, tree expr)
4166 build_special_member_call (NULL_TREE,
4167 complete_ctor_identifier,
4168 build_tree_list (NULL_TREE, expr),
4170 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4171 | LOOKUP_NO_CONVERSION
4172 | LOOKUP_CONSTRUCTOR_CALLABLE);
4175 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4176 bitwise or of LOOKUP_* values. If any errors are warnings are
4177 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4178 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4182 build_temp (tree expr, tree type, int flags,
4183 diagnostic_fn_t *diagnostic_fn)
4187 savew = warningcount, savee = errorcount;
4188 expr = build_special_member_call (NULL_TREE,
4189 complete_ctor_identifier,
4190 build_tree_list (NULL_TREE, expr),
4192 if (warningcount > savew)
4193 *diagnostic_fn = warning0;
4194 else if (errorcount > savee)
4195 *diagnostic_fn = error;
4197 *diagnostic_fn = NULL;
4202 /* Perform the conversions in CONVS on the expression EXPR. FN and
4203 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4204 indicates the `this' argument of a method. INNER is nonzero when
4205 being called to continue a conversion chain. It is negative when a
4206 reference binding will be applied, positive otherwise. If
4207 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4208 conversions will be emitted if appropriate. If C_CAST_P is true,
4209 this conversion is coming from a C-style cast; in that case,
4210 conversions to inaccessible bases are permitted. */
4213 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4214 int inner, bool issue_conversion_warnings,
4217 tree totype = convs->type;
4218 diagnostic_fn_t diagnostic_fn;
4221 && convs->kind != ck_user
4222 && convs->kind != ck_ambig
4223 && convs->kind != ck_ref_bind)
4225 conversion *t = convs;
4226 for (; t; t = convs->u.next)
4228 if (t->kind == ck_user || !t->bad_p)
4230 expr = convert_like_real (t, expr, fn, argnum, 1,
4231 /*issue_conversion_warnings=*/false,
4232 /*c_cast_p=*/false);
4235 else if (t->kind == ck_ambig)
4236 return convert_like_real (t, expr, fn, argnum, 1,
4237 /*issue_conversion_warnings=*/false,
4238 /*c_cast_p=*/false);
4239 else if (t->kind == ck_identity)
4242 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4244 pedwarn (" initializing argument %P of %qD", argnum, fn);
4245 return cp_convert (totype, expr);
4248 if (issue_conversion_warnings)
4250 tree t = non_reference (totype);
4252 /* Issue warnings about peculiar, but valid, uses of NULL. */
4253 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
4256 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4259 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4262 /* Warn about assigning a floating-point type to an integer type. */
4263 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
4264 && TREE_CODE (t) == INTEGER_TYPE)
4267 warning (OPT_Wconversion, "passing %qT for argument %P to %qD",
4268 TREE_TYPE (expr), argnum, fn);
4270 warning (OPT_Wconversion, "converting to %qT from %qT", t, TREE_TYPE (expr));
4274 switch (convs->kind)
4278 struct z_candidate *cand = convs->cand;
4279 tree convfn = cand->fn;
4282 if (DECL_CONSTRUCTOR_P (convfn))
4284 tree t = build_int_cst (build_pointer_type (DECL_CONTEXT (convfn)),
4287 args = build_tree_list (NULL_TREE, expr);
4288 /* We should never try to call the abstract or base constructor
4290 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (convfn)
4291 && !DECL_HAS_VTT_PARM_P (convfn));
4292 args = tree_cons (NULL_TREE, t, args);
4295 args = build_this (expr);
4296 expr = build_over_call (cand, LOOKUP_NORMAL);
4298 /* If this is a constructor or a function returning an aggr type,
4299 we need to build up a TARGET_EXPR. */
4300 if (DECL_CONSTRUCTOR_P (convfn))
4301 expr = build_cplus_new (totype, expr);
4303 /* The result of the call is then used to direct-initialize the object
4304 that is the destination of the copy-initialization. [dcl.init]
4306 Note that this step is not reflected in the conversion sequence;
4307 it affects the semantics when we actually perform the
4308 conversion, but is not considered during overload resolution.
4310 If the target is a class, that means call a ctor. */
4311 if (IS_AGGR_TYPE (totype)
4312 && (inner >= 0 || !lvalue_p (expr)))
4316 /* Core issue 84, now a DR, says that we don't
4317 allow UDCs for these args (which deliberately
4318 breaks copy-init of an auto_ptr<Base> from an
4319 auto_ptr<Derived>). */
4320 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4327 (" initializing argument %P of %qD from result of %qD",
4328 argnum, fn, convfn);
4331 (" initializing temporary from result of %qD", convfn);
4333 expr = build_cplus_new (totype, expr);
4338 if (type_unknown_p (expr))
4339 expr = instantiate_type (totype, expr, tf_warning_or_error);
4340 /* Convert a constant to its underlying value, unless we are
4341 about to bind it to a reference, in which case we need to
4342 leave it as an lvalue. */
4344 expr = decl_constant_value (expr);
4345 if (convs->check_copy_constructor_p)
4346 check_constructor_callable (totype, expr);
4349 /* Call build_user_type_conversion again for the error. */
4350 return build_user_type_conversion
4351 (totype, convs->u.expr, LOOKUP_NORMAL);
4357 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4358 convs->kind == ck_ref_bind ? -1 : 1,
4359 /*issue_conversion_warnings=*/false,
4361 if (expr == error_mark_node)
4362 return error_mark_node;
4364 switch (convs->kind)
4367 expr = convert_bitfield_to_declared_type (expr);
4368 if (! IS_AGGR_TYPE (totype))
4370 /* Else fall through. */
4372 if (convs->kind == ck_base && !convs->need_temporary_p)
4374 /* We are going to bind a reference directly to a base-class
4375 subobject of EXPR. */
4376 if (convs->check_copy_constructor_p)
4377 check_constructor_callable (TREE_TYPE (expr), expr);
4378 /* Build an expression for `*((base*) &expr)'. */
4379 expr = build_unary_op (ADDR_EXPR, expr, 0);
4380 expr = convert_to_base (expr, build_pointer_type (totype),
4381 !c_cast_p, /*nonnull=*/true);
4382 expr = build_indirect_ref (expr, "implicit conversion");
4386 /* Copy-initialization where the cv-unqualified version of the source
4387 type is the same class as, or a derived class of, the class of the
4388 destination [is treated as direct-initialization]. [dcl.init] */
4389 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4391 if (diagnostic_fn && fn)
4392 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4393 return build_cplus_new (totype, expr);
4397 tree ref_type = totype;
4399 /* If necessary, create a temporary. */
4400 if (convs->need_temporary_p || !lvalue_p (expr))
4402 tree type = convs->u.next->type;
4403 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4405 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
4407 /* If the reference is volatile or non-const, we
4408 cannot create a temporary. */
4409 if (lvalue & clk_bitfield)
4410 error ("cannot bind bitfield %qE to %qT",
4412 else if (lvalue & clk_packed)
4413 error ("cannot bind packed field %qE to %qT",
4416 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4417 return error_mark_node;
4419 /* If the source is a packed field, and we must use a copy
4420 constructor, then building the target expr will require
4421 binding the field to the reference parameter to the
4422 copy constructor, and we'll end up with an infinite
4423 loop. If we can use a bitwise copy, then we'll be
4425 if ((lvalue & clk_packed)
4426 && CLASS_TYPE_P (type)
4427 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4429 error ("cannot bind packed field %qE to %qT",
4431 return error_mark_node;
4433 expr = build_target_expr_with_type (expr, type);
4436 /* Take the address of the thing to which we will bind the
4438 expr = build_unary_op (ADDR_EXPR, expr, 1);
4439 if (expr == error_mark_node)
4440 return error_mark_node;
4442 /* Convert it to a pointer to the type referred to by the
4443 reference. This will adjust the pointer if a derived to
4444 base conversion is being performed. */
4445 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4447 /* Convert the pointer to the desired reference type. */
4448 return build_nop (ref_type, expr);
4452 return decay_conversion (expr);
4455 /* Warn about deprecated conversion if appropriate. */
4456 string_conv_p (totype, expr, 1);
4461 expr = convert_to_base (expr, totype, !c_cast_p,
4463 return build_nop (totype, expr);
4466 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4473 if (issue_conversion_warnings)
4474 expr = convert_and_check (totype, expr);
4476 expr = convert (totype, expr);
4481 /* Build a call to __builtin_trap. */
4484 call_builtin_trap (void)
4486 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4488 gcc_assert (fn != NULL);
4489 fn = build_call (fn, NULL_TREE);
4493 /* ARG is being passed to a varargs function. Perform any conversions
4494 required. Return the converted value. */
4497 convert_arg_to_ellipsis (tree arg)
4501 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4502 standard conversions are performed. */
4503 arg = decay_conversion (arg);
4506 If the argument has integral or enumeration type that is subject
4507 to the integral promotions (_conv.prom_), or a floating point
4508 type that is subject to the floating point promotion
4509 (_conv.fpprom_), the value of the argument is converted to the
4510 promoted type before the call. */
4511 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4512 && (TYPE_PRECISION (TREE_TYPE (arg))
4513 < TYPE_PRECISION (double_type_node)))
4514 arg = convert_to_real (double_type_node, arg);
4515 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4516 arg = perform_integral_promotions (arg);
4518 arg = require_complete_type (arg);
4520 if (arg != error_mark_node
4521 && !pod_type_p (TREE_TYPE (arg)))
4523 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4524 here and do a bitwise copy, but now cp_expr_size will abort if we
4526 If the call appears in the context of a sizeof expression,
4527 there is no need to emit a warning, since the expression won't be
4528 evaluated. We keep the builtin_trap just as a safety check. */
4529 if (!skip_evaluation)
4530 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4531 "call will abort at runtime", TREE_TYPE (arg));
4532 arg = call_builtin_trap ();
4533 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4540 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4543 build_x_va_arg (tree expr, tree type)
4545 if (processing_template_decl)
4546 return build_min (VA_ARG_EXPR, type, expr);
4548 type = complete_type_or_else (type, NULL_TREE);
4550 if (expr == error_mark_node || !type)
4551 return error_mark_node;
4553 if (! pod_type_p (type))
4555 /* Remove reference types so we don't ICE later on. */
4556 tree type1 = non_reference (type);
4557 /* Undefined behavior [expr.call] 5.2.2/7. */
4558 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4559 "call will abort at runtime", type);
4560 expr = convert (build_pointer_type (type1), null_node);
4561 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4562 call_builtin_trap (), expr);
4563 expr = build_indirect_ref (expr, NULL);
4567 return build_va_arg (expr, type);
4570 /* TYPE has been given to va_arg. Apply the default conversions which
4571 would have happened when passed via ellipsis. Return the promoted
4572 type, or the passed type if there is no change. */
4575 cxx_type_promotes_to (tree type)
4579 /* Perform the array-to-pointer and function-to-pointer
4581 type = type_decays_to (type);
4583 promote = type_promotes_to (type);
4584 if (same_type_p (type, promote))
4590 /* ARG is a default argument expression being passed to a parameter of
4591 the indicated TYPE, which is a parameter to FN. Do any required
4592 conversions. Return the converted value. */
4595 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4597 /* If the ARG is an unparsed default argument expression, the
4598 conversion cannot be performed. */
4599 if (TREE_CODE (arg) == DEFAULT_ARG)
4601 error ("the default argument for parameter %d of %qD has "
4602 "not yet been parsed",
4604 return error_mark_node;
4607 if (fn && DECL_TEMPLATE_INFO (fn))
4608 arg = tsubst_default_argument (fn, type, arg);
4610 arg = break_out_target_exprs (arg);
4612 if (TREE_CODE (arg) == CONSTRUCTOR)
4614 arg = digest_init (type, arg);
4615 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4616 "default argument", fn, parmnum);
4620 /* This could get clobbered by the following call. */
4621 if (TREE_HAS_CONSTRUCTOR (arg))
4622 arg = copy_node (arg);
4624 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4625 "default argument", fn, parmnum);
4626 arg = convert_for_arg_passing (type, arg);
4632 /* Returns the type which will really be used for passing an argument of
4636 type_passed_as (tree type)
4638 /* Pass classes with copy ctors by invisible reference. */
4639 if (TREE_ADDRESSABLE (type))
4641 type = build_reference_type (type);
4642 /* There are no other pointers to this temporary. */
4643 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4645 else if (targetm.calls.promote_prototypes (type)
4646 && INTEGRAL_TYPE_P (type)
4647 && COMPLETE_TYPE_P (type)
4648 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4649 TYPE_SIZE (integer_type_node)))
4650 type = integer_type_node;
4655 /* Actually perform the appropriate conversion. */
4658 convert_for_arg_passing (tree type, tree val)
4660 if (val == error_mark_node)
4662 /* Pass classes with copy ctors by invisible reference. */
4663 else if (TREE_ADDRESSABLE (type))
4664 val = build1 (ADDR_EXPR, build_reference_type (type), val);
4665 else if (targetm.calls.promote_prototypes (type)
4666 && INTEGRAL_TYPE_P (type)
4667 && COMPLETE_TYPE_P (type)
4668 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4669 TYPE_SIZE (integer_type_node)))
4670 val = perform_integral_promotions (val);
4671 if (warn_missing_format_attribute)
4673 tree rhstype = TREE_TYPE (val);
4674 const enum tree_code coder = TREE_CODE (rhstype);
4675 const enum tree_code codel = TREE_CODE (type);
4676 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4678 && check_missing_format_attribute (type, rhstype))
4679 warning (OPT_Wmissing_format_attribute,
4680 "argument of function call might be a candidate for a format attribute");
4685 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4686 which no conversions at all should be done. This is true for some
4687 builtins which don't act like normal functions. */
4690 magic_varargs_p (tree fn)
4692 if (DECL_BUILT_IN (fn))
4693 switch (DECL_FUNCTION_CODE (fn))
4695 case BUILT_IN_CLASSIFY_TYPE:
4696 case BUILT_IN_CONSTANT_P:
4697 case BUILT_IN_NEXT_ARG:
4698 case BUILT_IN_STDARG_START:
4699 case BUILT_IN_VA_START:
4708 /* Subroutine of the various build_*_call functions. Overload resolution
4709 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4710 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4711 bitmask of various LOOKUP_* flags which apply to the call itself. */
4714 build_over_call (struct z_candidate *cand, int flags)
4717 tree args = cand->args;
4718 conversion **convs = cand->convs;
4720 tree converted_args = NULL_TREE;
4721 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4726 /* In a template, there is no need to perform all of the work that
4727 is normally done. We are only interested in the type of the call
4728 expression, i.e., the return type of the function. Any semantic
4729 errors will be deferred until the template is instantiated. */
4730 if (processing_template_decl)
4734 return_type = TREE_TYPE (TREE_TYPE (fn));
4735 expr = build3 (CALL_EXPR, return_type, fn, args, NULL_TREE);
4736 if (TREE_THIS_VOLATILE (fn) && cfun)
4737 current_function_returns_abnormally = 1;
4738 if (!VOID_TYPE_P (return_type))
4739 require_complete_type (return_type);
4740 return convert_from_reference (expr);
4743 /* Give any warnings we noticed during overload resolution. */
4746 struct candidate_warning *w;
4747 for (w = cand->warnings; w; w = w->next)
4748 joust (cand, w->loser, 1);
4751 if (DECL_FUNCTION_MEMBER_P (fn))
4753 /* If FN is a template function, two cases must be considered.
4758 template <class T> void f();
4760 template <class T> struct B {
4764 struct C : A, B<int> {
4766 using B<int>::g; // #2
4769 In case #1 where `A::f' is a member template, DECL_ACCESS is
4770 recorded in the primary template but not in its specialization.
4771 We check access of FN using its primary template.
4773 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4774 because it is a member of class template B, DECL_ACCESS is
4775 recorded in the specialization `B<int>::g'. We cannot use its
4776 primary template because `B<T>::g' and `B<int>::g' may have
4777 different access. */
4778 if (DECL_TEMPLATE_INFO (fn)
4779 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4780 perform_or_defer_access_check (cand->access_path,
4781 DECL_TI_TEMPLATE (fn), fn);
4783 perform_or_defer_access_check (cand->access_path, fn, fn);
4786 if (args && TREE_CODE (args) != TREE_LIST)
4787 args = build_tree_list (NULL_TREE, args);
4790 /* The implicit parameters to a constructor are not considered by overload
4791 resolution, and must be of the proper type. */
4792 if (DECL_CONSTRUCTOR_P (fn))
4794 converted_args = tree_cons (NULL_TREE, TREE_VALUE (arg), converted_args);
4795 arg = TREE_CHAIN (arg);
4796 parm = TREE_CHAIN (parm);
4797 /* We should never try to call the abstract constructor. */
4798 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4800 if (DECL_HAS_VTT_PARM_P (fn))
4802 converted_args = tree_cons
4803 (NULL_TREE, TREE_VALUE (arg), converted_args);
4804 arg = TREE_CHAIN (arg);
4805 parm = TREE_CHAIN (parm);
4808 /* Bypass access control for 'this' parameter. */
4809 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4811 tree parmtype = TREE_VALUE (parm);
4812 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4816 if (convs[i]->bad_p)
4817 pedwarn ("passing %qT as %<this%> argument of %q#D discards qualifiers",
4818 TREE_TYPE (argtype), fn);
4820 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4821 X is called for an object that is not of type X, or of a type
4822 derived from X, the behavior is undefined.
4824 So we can assume that anything passed as 'this' is non-null, and
4825 optimize accordingly. */
4826 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4827 /* Convert to the base in which the function was declared. */
4828 gcc_assert (cand->conversion_path != NULL_TREE);
4829 converted_arg = build_base_path (PLUS_EXPR,
4831 cand->conversion_path,
4833 /* Check that the base class is accessible. */
4834 if (!accessible_base_p (TREE_TYPE (argtype),
4835 BINFO_TYPE (cand->conversion_path), true))
4836 error ("%qT is not an accessible base of %qT",
4837 BINFO_TYPE (cand->conversion_path),
4838 TREE_TYPE (argtype));
4839 /* If fn was found by a using declaration, the conversion path
4840 will be to the derived class, not the base declaring fn. We
4841 must convert from derived to base. */
4842 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4843 TREE_TYPE (parmtype), ba_unique, NULL);
4844 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4847 converted_args = tree_cons (NULL_TREE, converted_arg, converted_args);
4848 parm = TREE_CHAIN (parm);
4849 arg = TREE_CHAIN (arg);
4855 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4857 tree type = TREE_VALUE (parm);
4861 /* Don't make a copy here if build_call is going to. */
4862 if (conv->kind == ck_rvalue
4863 && !TREE_ADDRESSABLE (complete_type (type)))
4864 conv = conv->u.next;
4866 val = convert_like_with_context
4867 (conv, TREE_VALUE (arg), fn, i - is_method);
4869 val = convert_for_arg_passing (type, val);
4870 converted_args = tree_cons (NULL_TREE, val, converted_args);
4873 /* Default arguments */
4874 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
4876 = tree_cons (NULL_TREE,
4877 convert_default_arg (TREE_VALUE (parm),
4878 TREE_PURPOSE (parm),
4883 for (; arg; arg = TREE_CHAIN (arg))
4885 tree a = TREE_VALUE (arg);
4886 if (magic_varargs_p (fn))
4887 /* Do no conversions for magic varargs. */;
4889 a = convert_arg_to_ellipsis (a);
4890 converted_args = tree_cons (NULL_TREE, a, converted_args);
4893 converted_args = nreverse (converted_args);
4895 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
4896 converted_args, TYPE_ARG_TYPES (TREE_TYPE (fn)));
4898 /* Avoid actually calling copy constructors and copy assignment operators,
4901 if (! flag_elide_constructors)
4902 /* Do things the hard way. */;
4903 else if (cand->num_convs == 1 && DECL_COPY_CONSTRUCTOR_P (fn))
4906 arg = skip_artificial_parms_for (fn, converted_args);
4907 arg = TREE_VALUE (arg);
4909 /* Pull out the real argument, disregarding const-correctness. */
4911 while (TREE_CODE (targ) == NOP_EXPR
4912 || TREE_CODE (targ) == NON_LVALUE_EXPR
4913 || TREE_CODE (targ) == CONVERT_EXPR)
4914 targ = TREE_OPERAND (targ, 0);
4915 if (TREE_CODE (targ) == ADDR_EXPR)
4917 targ = TREE_OPERAND (targ, 0);
4918 if (!same_type_ignoring_top_level_qualifiers_p
4919 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
4928 arg = build_indirect_ref (arg, 0);
4930 /* [class.copy]: the copy constructor is implicitly defined even if
4931 the implementation elided its use. */
4932 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
4935 /* If we're creating a temp and we already have one, don't create a
4936 new one. If we're not creating a temp but we get one, use
4937 INIT_EXPR to collapse the temp into our target. Otherwise, if the
4938 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
4939 temp or an INIT_EXPR otherwise. */
4940 if (integer_zerop (TREE_VALUE (args)))
4942 if (TREE_CODE (arg) == TARGET_EXPR)
4944 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4945 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
4947 else if (TREE_CODE (arg) == TARGET_EXPR
4948 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4950 tree to = stabilize_reference
4951 (build_indirect_ref (TREE_VALUE (args), 0));
4953 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
4957 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
4959 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
4961 tree to = stabilize_reference
4962 (build_indirect_ref (TREE_VALUE (converted_args), 0));
4963 tree type = TREE_TYPE (to);
4964 tree as_base = CLASSTYPE_AS_BASE (type);
4966 arg = TREE_VALUE (TREE_CHAIN (converted_args));
4967 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
4969 arg = build_indirect_ref (arg, 0);
4970 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
4974 /* We must only copy the non-tail padding parts.
4975 Use __builtin_memcpy for the bitwise copy. */
4979 args = tree_cons (NULL, TYPE_SIZE_UNIT (as_base), NULL);
4980 args = tree_cons (NULL, arg, args);
4981 t = build_unary_op (ADDR_EXPR, to, 0);
4982 args = tree_cons (NULL, t, args);
4983 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
4984 t = build_call (t, args);
4986 t = convert (TREE_TYPE (TREE_VALUE (args)), t);
4987 val = build_indirect_ref (t, 0);
4995 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
4997 tree t, *p = &TREE_VALUE (converted_args);
4998 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (*p)),
5001 gcc_assert (binfo && binfo != error_mark_node);
5003 *p = build_base_path (PLUS_EXPR, *p, binfo, 1);
5004 if (TREE_SIDE_EFFECTS (*p))
5005 *p = save_expr (*p);
5006 t = build_pointer_type (TREE_TYPE (fn));
5007 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5008 fn = build_java_interface_fn_ref (fn, *p);
5010 fn = build_vfn_ref (*p, DECL_VINDEX (fn));
5013 else if (DECL_INLINE (fn))
5014 fn = inline_conversion (fn);
5016 fn = build_addr_func (fn);
5018 return build_cxx_call (fn, converted_args);
5021 /* Build and return a call to FN, using ARGS. This function performs
5022 no overload resolution, conversion, or other high-level
5026 build_cxx_call (tree fn, tree args)
5030 fn = build_call (fn, args);
5032 /* If this call might throw an exception, note that fact. */
5033 fndecl = get_callee_fndecl (fn);
5034 if ((!fndecl || !TREE_NOTHROW (fndecl))
5035 && at_function_scope_p ()
5037 cp_function_chain->can_throw = 1;
5039 /* Some built-in function calls will be evaluated at compile-time in
5041 fn = fold_if_not_in_template (fn);
5043 if (VOID_TYPE_P (TREE_TYPE (fn)))
5046 fn = require_complete_type (fn);
5047 if (fn == error_mark_node)
5048 return error_mark_node;
5050 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
5051 fn = build_cplus_new (TREE_TYPE (fn), fn);
5052 return convert_from_reference (fn);
5055 static GTY(()) tree java_iface_lookup_fn;
5057 /* Make an expression which yields the address of the Java interface
5058 method FN. This is achieved by generating a call to libjava's
5059 _Jv_LookupInterfaceMethodIdx(). */
5062 build_java_interface_fn_ref (tree fn, tree instance)
5064 tree lookup_args, lookup_fn, method, idx;
5065 tree klass_ref, iface, iface_ref;
5068 if (!java_iface_lookup_fn)
5070 tree endlink = build_void_list_node ();
5071 tree t = tree_cons (NULL_TREE, ptr_type_node,
5072 tree_cons (NULL_TREE, ptr_type_node,
5073 tree_cons (NULL_TREE, java_int_type_node,
5075 java_iface_lookup_fn
5076 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx",
5077 build_function_type (ptr_type_node, t),
5078 0, NOT_BUILT_IN, NULL, NULL_TREE);
5081 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5082 This is the first entry in the vtable. */
5083 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
5086 /* Get the java.lang.Class pointer for the interface being called. */
5087 iface = DECL_CONTEXT (fn);
5088 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5089 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5090 || DECL_CONTEXT (iface_ref) != iface)
5092 error ("could not find class$ field in java interface type %qT",
5094 return error_mark_node;
5096 iface_ref = build_address (iface_ref);
5097 iface_ref = convert (build_pointer_type (iface), iface_ref);
5099 /* Determine the itable index of FN. */
5101 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5103 if (!DECL_VIRTUAL_P (method))
5109 idx = build_int_cst (NULL_TREE, i);
5111 lookup_args = tree_cons (NULL_TREE, klass_ref,
5112 tree_cons (NULL_TREE, iface_ref,
5113 build_tree_list (NULL_TREE, idx)));
5114 lookup_fn = build1 (ADDR_EXPR,
5115 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5116 java_iface_lookup_fn);
5117 return build3 (CALL_EXPR, ptr_type_node, lookup_fn, lookup_args, NULL_TREE);
5120 /* Returns the value to use for the in-charge parameter when making a
5121 call to a function with the indicated NAME.
5123 FIXME:Can't we find a neater way to do this mapping? */
5126 in_charge_arg_for_name (tree name)
5128 if (name == base_ctor_identifier
5129 || name == base_dtor_identifier)
5130 return integer_zero_node;
5131 else if (name == complete_ctor_identifier)
5132 return integer_one_node;
5133 else if (name == complete_dtor_identifier)
5134 return integer_two_node;
5135 else if (name == deleting_dtor_identifier)
5136 return integer_three_node;
5138 /* This function should only be called with one of the names listed
5144 /* Build a call to a constructor, destructor, or an assignment
5145 operator for INSTANCE, an expression with class type. NAME
5146 indicates the special member function to call; ARGS are the
5147 arguments. BINFO indicates the base of INSTANCE that is to be
5148 passed as the `this' parameter to the member function called.
5150 FLAGS are the LOOKUP_* flags to use when processing the call.
5152 If NAME indicates a complete object constructor, INSTANCE may be
5153 NULL_TREE. In this case, the caller will call build_cplus_new to
5154 store the newly constructed object into a VAR_DECL. */
5157 build_special_member_call (tree instance, tree name, tree args,
5158 tree binfo, int flags)
5161 /* The type of the subobject to be constructed or destroyed. */
5164 gcc_assert (name == complete_ctor_identifier
5165 || name == base_ctor_identifier
5166 || name == complete_dtor_identifier
5167 || name == base_dtor_identifier
5168 || name == deleting_dtor_identifier
5169 || name == ansi_assopname (NOP_EXPR));
5172 /* Resolve the name. */
5173 if (!complete_type_or_else (binfo, NULL_TREE))
5174 return error_mark_node;
5176 binfo = TYPE_BINFO (binfo);
5179 gcc_assert (binfo != NULL_TREE);
5181 class_type = BINFO_TYPE (binfo);
5183 /* Handle the special case where INSTANCE is NULL_TREE. */
5184 if (name == complete_ctor_identifier && !instance)
5186 instance = build_int_cst (build_pointer_type (class_type), 0);
5187 instance = build1 (INDIRECT_REF, class_type, instance);
5191 if (name == complete_dtor_identifier
5192 || name == base_dtor_identifier
5193 || name == deleting_dtor_identifier)
5194 gcc_assert (args == NULL_TREE);
5196 /* Convert to the base class, if necessary. */
5197 if (!same_type_ignoring_top_level_qualifiers_p
5198 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5200 if (name != ansi_assopname (NOP_EXPR))
5201 /* For constructors and destructors, either the base is
5202 non-virtual, or it is virtual but we are doing the
5203 conversion from a constructor or destructor for the
5204 complete object. In either case, we can convert
5206 instance = convert_to_base_statically (instance, binfo);
5208 /* However, for assignment operators, we must convert
5209 dynamically if the base is virtual. */
5210 instance = build_base_path (PLUS_EXPR, instance,
5211 binfo, /*nonnull=*/1);
5215 gcc_assert (instance != NULL_TREE);
5217 fns = lookup_fnfields (binfo, name, 1);
5219 /* When making a call to a constructor or destructor for a subobject
5220 that uses virtual base classes, pass down a pointer to a VTT for
5222 if ((name == base_ctor_identifier
5223 || name == base_dtor_identifier)
5224 && CLASSTYPE_VBASECLASSES (class_type))
5229 /* If the current function is a complete object constructor
5230 or destructor, then we fetch the VTT directly.
5231 Otherwise, we look it up using the VTT we were given. */
5232 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5233 vtt = decay_conversion (vtt);
5234 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5235 build2 (EQ_EXPR, boolean_type_node,
5236 current_in_charge_parm, integer_zero_node),
5239 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5240 sub_vtt = build2 (PLUS_EXPR, TREE_TYPE (vtt), vtt,
5241 BINFO_SUBVTT_INDEX (binfo));
5243 args = tree_cons (NULL_TREE, sub_vtt, args);
5246 return build_new_method_call (instance, fns, args,
5247 TYPE_BINFO (BINFO_TYPE (binfo)),
5248 flags, /*fn=*/NULL);
5251 /* Return the NAME, as a C string. The NAME indicates a function that
5252 is a member of TYPE. *FREE_P is set to true if the caller must
5253 free the memory returned.
5255 Rather than go through all of this, we should simply set the names
5256 of constructors and destructors appropriately, and dispense with
5257 ctor_identifier, dtor_identifier, etc. */
5260 name_as_c_string (tree name, tree type, bool *free_p)
5264 /* Assume that we will not allocate memory. */
5266 /* Constructors and destructors are special. */
5267 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5270 = (char *) IDENTIFIER_POINTER (constructor_name (type));
5271 /* For a destructor, add the '~'. */
5272 if (name == complete_dtor_identifier
5273 || name == base_dtor_identifier
5274 || name == deleting_dtor_identifier)
5276 pretty_name = concat ("~", pretty_name, NULL);
5277 /* Remember that we need to free the memory allocated. */
5281 else if (IDENTIFIER_TYPENAME_P (name))
5283 pretty_name = concat ("operator ",
5284 type_as_string (TREE_TYPE (name),
5285 TFF_PLAIN_IDENTIFIER),
5287 /* Remember that we need to free the memory allocated. */
5291 pretty_name = (char *) IDENTIFIER_POINTER (name);
5296 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5297 be set, upon return, to the function called. */
5300 build_new_method_call (tree instance, tree fns, tree args,
5301 tree conversion_path, int flags,
5304 struct z_candidate *candidates = 0, *cand;
5305 tree explicit_targs = NULL_TREE;
5306 tree basetype = NULL_TREE;
5309 tree mem_args = NULL_TREE, instance_ptr;
5315 int template_only = 0;
5322 gcc_assert (instance != NULL_TREE);
5324 /* We don't know what function we're going to call, yet. */
5328 if (error_operand_p (instance)
5329 || error_operand_p (fns)
5330 || args == error_mark_node)
5331 return error_mark_node;
5333 if (!BASELINK_P (fns))
5335 error ("call to non-function %qD", fns);
5336 return error_mark_node;
5339 orig_instance = instance;
5343 /* Dismantle the baselink to collect all the information we need. */
5344 if (!conversion_path)
5345 conversion_path = BASELINK_BINFO (fns);
5346 access_binfo = BASELINK_ACCESS_BINFO (fns);
5347 optype = BASELINK_OPTYPE (fns);
5348 fns = BASELINK_FUNCTIONS (fns);
5349 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5351 explicit_targs = TREE_OPERAND (fns, 1);
5352 fns = TREE_OPERAND (fns, 0);
5355 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5356 || TREE_CODE (fns) == TEMPLATE_DECL
5357 || TREE_CODE (fns) == OVERLOAD);
5358 fn = get_first_fn (fns);
5359 name = DECL_NAME (fn);
5361 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5362 gcc_assert (CLASS_TYPE_P (basetype));
5364 if (processing_template_decl)
5366 instance = build_non_dependent_expr (instance);
5367 args = build_non_dependent_args (orig_args);
5370 /* The USER_ARGS are the arguments we will display to users if an
5371 error occurs. The USER_ARGS should not include any
5372 compiler-generated arguments. The "this" pointer hasn't been
5373 added yet. However, we must remove the VTT pointer if this is a
5374 call to a base-class constructor or destructor. */
5376 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5378 /* Callers should explicitly indicate whether they want to construct
5379 the complete object or just the part without virtual bases. */
5380 gcc_assert (name != ctor_identifier);
5381 /* Similarly for destructors. */
5382 gcc_assert (name != dtor_identifier);
5383 /* Remove the VTT pointer, if present. */
5384 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5385 && CLASSTYPE_VBASECLASSES (basetype))
5386 user_args = TREE_CHAIN (user_args);
5389 /* Process the argument list. */
5390 args = resolve_args (args);
5391 if (args == error_mark_node)
5392 return error_mark_node;
5394 instance_ptr = build_this (instance);
5396 /* It's OK to call destructors on cv-qualified objects. Therefore,
5397 convert the INSTANCE_PTR to the unqualified type, if necessary. */
5398 if (DECL_DESTRUCTOR_P (fn))
5400 tree type = build_pointer_type (basetype);
5401 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5402 instance_ptr = build_nop (type, instance_ptr);
5403 name = complete_dtor_identifier;
5406 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5407 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5409 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5410 p = conversion_obstack_alloc (0);
5412 for (fn = fns; fn; fn = OVL_NEXT (fn))
5414 tree t = OVL_CURRENT (fn);
5417 /* We can end up here for copy-init of same or base class. */
5418 if ((flags & LOOKUP_ONLYCONVERTING)
5419 && DECL_NONCONVERTING_P (t))
5422 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5423 this_arglist = mem_args;
5425 this_arglist = args;
5427 if (TREE_CODE (t) == TEMPLATE_DECL)
5428 /* A member template. */
5429 add_template_candidate (&candidates, t,
5432 this_arglist, optype,
5437 else if (! template_only)
5438 add_function_candidate (&candidates, t,
5446 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5449 if (!COMPLETE_TYPE_P (basetype))
5450 cxx_incomplete_type_error (instance_ptr, basetype);
5456 pretty_name = name_as_c_string (name, basetype, &free_p);
5457 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5458 basetype, pretty_name, user_args,
5459 TREE_TYPE (TREE_TYPE (instance_ptr)));
5463 print_z_candidates (candidates);
5464 call = error_mark_node;
5468 cand = tourney (candidates);
5474 pretty_name = name_as_c_string (name, basetype, &free_p);
5475 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5477 print_z_candidates (candidates);
5480 call = error_mark_node;
5486 if (!(flags & LOOKUP_NONVIRTUAL)
5487 && DECL_PURE_VIRTUAL_P (fn)
5488 && instance == current_class_ref
5489 && (DECL_CONSTRUCTOR_P (current_function_decl)
5490 || DECL_DESTRUCTOR_P (current_function_decl)))
5491 /* This is not an error, it is runtime undefined
5493 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
5494 "abstract virtual %q#D called from constructor"
5495 : "abstract virtual %q#D called from destructor"),
5498 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
5499 && is_dummy_object (instance_ptr))
5501 error ("cannot call member function %qD without object",
5503 call = error_mark_node;
5507 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
5508 && resolves_to_fixed_type_p (instance, 0))
5509 flags |= LOOKUP_NONVIRTUAL;
5510 /* Now we know what function is being called. */
5513 /* Build the actual CALL_EXPR. */
5514 call = build_over_call (cand, flags);
5515 /* In an expression of the form `a->f()' where `f' turns
5516 out to be a static member function, `a' is
5517 none-the-less evaluated. */
5518 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
5519 && !is_dummy_object (instance_ptr)
5520 && TREE_SIDE_EFFECTS (instance_ptr))
5521 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5522 instance_ptr, call);
5527 if (processing_template_decl && call != error_mark_node)
5528 call = (build_min_non_dep
5530 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5531 orig_args, NULL_TREE));
5533 /* Free all the conversions we allocated. */
5534 obstack_free (&conversion_obstack, p);
5539 /* Returns true iff standard conversion sequence ICS1 is a proper
5540 subsequence of ICS2. */
5543 is_subseq (conversion *ics1, conversion *ics2)
5545 /* We can assume that a conversion of the same code
5546 between the same types indicates a subsequence since we only get
5547 here if the types we are converting from are the same. */
5549 while (ics1->kind == ck_rvalue
5550 || ics1->kind == ck_lvalue)
5551 ics1 = ics1->u.next;
5555 while (ics2->kind == ck_rvalue
5556 || ics2->kind == ck_lvalue)
5557 ics2 = ics2->u.next;
5559 if (ics2->kind == ck_user
5560 || ics2->kind == ck_ambig
5561 || ics2->kind == ck_identity)
5562 /* At this point, ICS1 cannot be a proper subsequence of
5563 ICS2. We can get a USER_CONV when we are comparing the
5564 second standard conversion sequence of two user conversion
5568 ics2 = ics2->u.next;
5570 if (ics2->kind == ics1->kind
5571 && same_type_p (ics2->type, ics1->type)
5572 && same_type_p (ics2->u.next->type,
5573 ics1->u.next->type))
5578 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5579 be any _TYPE nodes. */
5582 is_properly_derived_from (tree derived, tree base)
5584 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5585 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5588 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5589 considers every class derived from itself. */
5590 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5591 && DERIVED_FROM_P (base, derived));
5594 /* We build the ICS for an implicit object parameter as a pointer
5595 conversion sequence. However, such a sequence should be compared
5596 as if it were a reference conversion sequence. If ICS is the
5597 implicit conversion sequence for an implicit object parameter,
5598 modify it accordingly. */
5601 maybe_handle_implicit_object (conversion **ics)
5605 /* [over.match.funcs]
5607 For non-static member functions, the type of the
5608 implicit object parameter is "reference to cv X"
5609 where X is the class of which the function is a
5610 member and cv is the cv-qualification on the member
5611 function declaration. */
5612 conversion *t = *ics;
5613 tree reference_type;
5615 /* The `this' parameter is a pointer to a class type. Make the
5616 implicit conversion talk about a reference to that same class
5618 reference_type = TREE_TYPE (t->type);
5619 reference_type = build_reference_type (reference_type);
5621 if (t->kind == ck_qual)
5623 if (t->kind == ck_ptr)
5625 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5626 t = direct_reference_binding (reference_type, t);
5631 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5632 and return the type to which the reference refers. Otherwise,
5633 leave *ICS unchanged and return NULL_TREE. */
5636 maybe_handle_ref_bind (conversion **ics)
5638 if ((*ics)->kind == ck_ref_bind)
5640 conversion *old_ics = *ics;
5641 tree type = TREE_TYPE (old_ics->type);
5642 *ics = old_ics->u.next;
5643 (*ics)->user_conv_p = old_ics->user_conv_p;
5644 (*ics)->bad_p = old_ics->bad_p;
5651 /* Compare two implicit conversion sequences according to the rules set out in
5652 [over.ics.rank]. Return values:
5654 1: ics1 is better than ics2
5655 -1: ics2 is better than ics1
5656 0: ics1 and ics2 are indistinguishable */
5659 compare_ics (conversion *ics1, conversion *ics2)
5665 tree deref_from_type1 = NULL_TREE;
5666 tree deref_from_type2 = NULL_TREE;
5667 tree deref_to_type1 = NULL_TREE;
5668 tree deref_to_type2 = NULL_TREE;
5669 conversion_rank rank1, rank2;
5671 /* REF_BINDING is nonzero if the result of the conversion sequence
5672 is a reference type. In that case TARGET_TYPE is the
5673 type referred to by the reference. */
5677 /* Handle implicit object parameters. */
5678 maybe_handle_implicit_object (&ics1);
5679 maybe_handle_implicit_object (&ics2);
5681 /* Handle reference parameters. */
5682 target_type1 = maybe_handle_ref_bind (&ics1);
5683 target_type2 = maybe_handle_ref_bind (&ics2);
5687 When comparing the basic forms of implicit conversion sequences (as
5688 defined in _over.best.ics_)
5690 --a standard conversion sequence (_over.ics.scs_) is a better
5691 conversion sequence than a user-defined conversion sequence
5692 or an ellipsis conversion sequence, and
5694 --a user-defined conversion sequence (_over.ics.user_) is a
5695 better conversion sequence than an ellipsis conversion sequence
5696 (_over.ics.ellipsis_). */
5697 rank1 = CONVERSION_RANK (ics1);
5698 rank2 = CONVERSION_RANK (ics2);
5702 else if (rank1 < rank2)
5705 if (rank1 == cr_bad)
5707 /* XXX Isn't this an extension? */
5708 /* Both ICS are bad. We try to make a decision based on what
5709 would have happened if they'd been good. */
5710 if (ics1->user_conv_p > ics2->user_conv_p
5711 || ics1->rank > ics2->rank)
5713 else if (ics1->user_conv_p < ics2->user_conv_p
5714 || ics1->rank < ics2->rank)
5717 /* We couldn't make up our minds; try to figure it out below. */
5720 if (ics1->ellipsis_p)
5721 /* Both conversions are ellipsis conversions. */
5724 /* User-defined conversion sequence U1 is a better conversion sequence
5725 than another user-defined conversion sequence U2 if they contain the
5726 same user-defined conversion operator or constructor and if the sec-
5727 ond standard conversion sequence of U1 is better than the second
5728 standard conversion sequence of U2. */
5730 if (ics1->user_conv_p)
5735 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5736 if (t1->kind == ck_ambig)
5738 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5739 if (t2->kind == ck_ambig)
5742 if (t1->cand->fn != t2->cand->fn)
5745 /* We can just fall through here, after setting up
5746 FROM_TYPE1 and FROM_TYPE2. */
5747 from_type1 = t1->type;
5748 from_type2 = t2->type;
5755 /* We're dealing with two standard conversion sequences.
5759 Standard conversion sequence S1 is a better conversion
5760 sequence than standard conversion sequence S2 if
5762 --S1 is a proper subsequence of S2 (comparing the conversion
5763 sequences in the canonical form defined by _over.ics.scs_,
5764 excluding any Lvalue Transformation; the identity
5765 conversion sequence is considered to be a subsequence of
5766 any non-identity conversion sequence */
5769 while (t1->kind != ck_identity)
5771 from_type1 = t1->type;
5774 while (t2->kind != ck_identity)
5776 from_type2 = t2->type;
5779 if (same_type_p (from_type1, from_type2))
5781 if (is_subseq (ics1, ics2))
5783 if (is_subseq (ics2, ics1))
5786 /* Otherwise, one sequence cannot be a subsequence of the other; they
5787 don't start with the same type. This can happen when comparing the
5788 second standard conversion sequence in two user-defined conversion
5795 --the rank of S1 is better than the rank of S2 (by the rules
5798 Standard conversion sequences are ordered by their ranks: an Exact
5799 Match is a better conversion than a Promotion, which is a better
5800 conversion than a Conversion.
5802 Two conversion sequences with the same rank are indistinguishable
5803 unless one of the following rules applies:
5805 --A conversion that is not a conversion of a pointer, or pointer
5806 to member, to bool is better than another conversion that is such
5809 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5810 so that we do not have to check it explicitly. */
5811 if (ics1->rank < ics2->rank)
5813 else if (ics2->rank < ics1->rank)
5816 to_type1 = ics1->type;
5817 to_type2 = ics2->type;
5819 if (TYPE_PTR_P (from_type1)
5820 && TYPE_PTR_P (from_type2)
5821 && TYPE_PTR_P (to_type1)
5822 && TYPE_PTR_P (to_type2))
5824 deref_from_type1 = TREE_TYPE (from_type1);
5825 deref_from_type2 = TREE_TYPE (from_type2);
5826 deref_to_type1 = TREE_TYPE (to_type1);
5827 deref_to_type2 = TREE_TYPE (to_type2);
5829 /* The rules for pointers to members A::* are just like the rules
5830 for pointers A*, except opposite: if B is derived from A then
5831 A::* converts to B::*, not vice versa. For that reason, we
5832 switch the from_ and to_ variables here. */
5833 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5834 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5835 || (TYPE_PTRMEMFUNC_P (from_type1)
5836 && TYPE_PTRMEMFUNC_P (from_type2)
5837 && TYPE_PTRMEMFUNC_P (to_type1)
5838 && TYPE_PTRMEMFUNC_P (to_type2)))
5840 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5841 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5842 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5843 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5846 if (deref_from_type1 != NULL_TREE
5847 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5848 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5850 /* This was one of the pointer or pointer-like conversions.
5854 --If class B is derived directly or indirectly from class A,
5855 conversion of B* to A* is better than conversion of B* to
5856 void*, and conversion of A* to void* is better than
5857 conversion of B* to void*. */
5858 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5859 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5861 if (is_properly_derived_from (deref_from_type1,
5864 else if (is_properly_derived_from (deref_from_type2,
5868 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
5869 || TREE_CODE (deref_to_type2) == VOID_TYPE)
5871 if (same_type_p (deref_from_type1, deref_from_type2))
5873 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
5875 if (is_properly_derived_from (deref_from_type1,
5879 /* We know that DEREF_TO_TYPE1 is `void' here. */
5880 else if (is_properly_derived_from (deref_from_type1,
5885 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
5886 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
5890 --If class B is derived directly or indirectly from class A
5891 and class C is derived directly or indirectly from B,
5893 --conversion of C* to B* is better than conversion of C* to
5896 --conversion of B* to A* is better than conversion of C* to
5898 if (same_type_p (deref_from_type1, deref_from_type2))
5900 if (is_properly_derived_from (deref_to_type1,
5903 else if (is_properly_derived_from (deref_to_type2,
5907 else if (same_type_p (deref_to_type1, deref_to_type2))
5909 if (is_properly_derived_from (deref_from_type2,
5912 else if (is_properly_derived_from (deref_from_type1,
5918 else if (CLASS_TYPE_P (non_reference (from_type1))
5919 && same_type_p (from_type1, from_type2))
5921 tree from = non_reference (from_type1);
5925 --binding of an expression of type C to a reference of type
5926 B& is better than binding an expression of type C to a
5927 reference of type A&
5929 --conversion of C to B is better than conversion of C to A, */
5930 if (is_properly_derived_from (from, to_type1)
5931 && is_properly_derived_from (from, to_type2))
5933 if (is_properly_derived_from (to_type1, to_type2))
5935 else if (is_properly_derived_from (to_type2, to_type1))
5939 else if (CLASS_TYPE_P (non_reference (to_type1))
5940 && same_type_p (to_type1, to_type2))
5942 tree to = non_reference (to_type1);
5946 --binding of an expression of type B to a reference of type
5947 A& is better than binding an expression of type C to a
5948 reference of type A&,
5950 --conversion of B to A is better than conversion of C to A */
5951 if (is_properly_derived_from (from_type1, to)
5952 && is_properly_derived_from (from_type2, to))
5954 if (is_properly_derived_from (from_type2, from_type1))
5956 else if (is_properly_derived_from (from_type1, from_type2))
5963 --S1 and S2 differ only in their qualification conversion and yield
5964 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
5965 qualification signature of type T1 is a proper subset of the cv-
5966 qualification signature of type T2 */
5967 if (ics1->kind == ck_qual
5968 && ics2->kind == ck_qual
5969 && same_type_p (from_type1, from_type2))
5970 return comp_cv_qual_signature (to_type1, to_type2);
5974 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
5975 types to which the references refer are the same type except for
5976 top-level cv-qualifiers, and the type to which the reference
5977 initialized by S2 refers is more cv-qualified than the type to
5978 which the reference initialized by S1 refers */
5980 if (target_type1 && target_type2
5981 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
5982 return comp_cv_qualification (target_type2, target_type1);
5984 /* Neither conversion sequence is better than the other. */
5988 /* The source type for this standard conversion sequence. */
5991 source_type (conversion *t)
5993 for (;; t = t->u.next)
5995 if (t->kind == ck_user
5996 || t->kind == ck_ambig
5997 || t->kind == ck_identity)
6003 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6004 a pointer to LOSER and re-running joust to produce the warning if WINNER
6005 is actually used. */
6008 add_warning (struct z_candidate *winner, struct z_candidate *loser)
6010 candidate_warning *cw = (candidate_warning *)
6011 conversion_obstack_alloc (sizeof (candidate_warning));
6013 cw->next = winner->warnings;
6014 winner->warnings = cw;
6017 /* Compare two candidates for overloading as described in
6018 [over.match.best]. Return values:
6020 1: cand1 is better than cand2
6021 -1: cand2 is better than cand1
6022 0: cand1 and cand2 are indistinguishable */
6025 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
6028 int off1 = 0, off2 = 0;
6032 /* Candidates that involve bad conversions are always worse than those
6034 if (cand1->viable > cand2->viable)
6036 if (cand1->viable < cand2->viable)
6039 /* If we have two pseudo-candidates for conversions to the same type,
6040 or two candidates for the same function, arbitrarily pick one. */
6041 if (cand1->fn == cand2->fn
6042 && (IS_TYPE_OR_DECL_P (cand1->fn)))
6045 /* a viable function F1
6046 is defined to be a better function than another viable function F2 if
6047 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6048 ICSi(F2), and then */
6050 /* for some argument j, ICSj(F1) is a better conversion sequence than
6053 /* For comparing static and non-static member functions, we ignore
6054 the implicit object parameter of the non-static function. The
6055 standard says to pretend that the static function has an object
6056 parm, but that won't work with operator overloading. */
6057 len = cand1->num_convs;
6058 if (len != cand2->num_convs)
6060 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
6061 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
6063 gcc_assert (static_1 != static_2);
6074 for (i = 0; i < len; ++i)
6076 conversion *t1 = cand1->convs[i + off1];
6077 conversion *t2 = cand2->convs[i + off2];
6078 int comp = compare_ics (t1, t2);
6083 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
6084 == cr_std + cr_promotion)
6085 && t1->kind == ck_std
6086 && t2->kind == ck_std
6087 && TREE_CODE (t1->type) == INTEGER_TYPE
6088 && TREE_CODE (t2->type) == INTEGER_TYPE
6089 && (TYPE_PRECISION (t1->type)
6090 == TYPE_PRECISION (t2->type))
6091 && (TYPE_UNSIGNED (t1->u.next->type)
6092 || (TREE_CODE (t1->u.next->type)
6095 tree type = t1->u.next->type;
6097 struct z_candidate *w, *l;
6099 type1 = t1->type, type2 = t2->type,
6100 w = cand1, l = cand2;
6102 type1 = t2->type, type2 = t1->type,
6103 w = cand2, l = cand1;
6107 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
6108 type, type1, type2);
6109 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
6115 if (winner && comp != winner)
6124 /* warn about confusing overload resolution for user-defined conversions,
6125 either between a constructor and a conversion op, or between two
6127 if (winner && warn_conversion && cand1->second_conv
6128 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
6129 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
6131 struct z_candidate *w, *l;
6132 bool give_warning = false;
6135 w = cand1, l = cand2;
6137 w = cand2, l = cand1;
6139 /* We don't want to complain about `X::operator T1 ()'
6140 beating `X::operator T2 () const', when T2 is a no less
6141 cv-qualified version of T1. */
6142 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
6143 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
6145 tree t = TREE_TYPE (TREE_TYPE (l->fn));
6146 tree f = TREE_TYPE (TREE_TYPE (w->fn));
6148 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6153 if (!comp_ptr_ttypes (t, f))
6154 give_warning = true;
6157 give_warning = true;
6163 tree source = source_type (w->convs[0]);
6164 if (! DECL_CONSTRUCTOR_P (w->fn))
6165 source = TREE_TYPE (source);
6166 warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn);
6167 warning (OPT_Wconversion, " for conversion from %qT to %qT",
6168 source, w->second_conv->type);
6169 inform (" because conversion sequence for the argument is better");
6179 F1 is a non-template function and F2 is a template function
6182 if (!cand1->template_decl && cand2->template_decl)
6184 else if (cand1->template_decl && !cand2->template_decl)
6188 F1 and F2 are template functions and the function template for F1 is
6189 more specialized than the template for F2 according to the partial
6192 if (cand1->template_decl && cand2->template_decl)
6194 winner = more_specialized_fn
6195 (TI_TEMPLATE (cand1->template_decl),
6196 TI_TEMPLATE (cand2->template_decl),
6197 /* [temp.func.order]: The presence of unused ellipsis and default
6198 arguments has no effect on the partial ordering of function
6199 templates. add_function_candidate() will not have
6200 counted the "this" argument for constructors. */
6201 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
6207 the context is an initialization by user-defined conversion (see
6208 _dcl.init_ and _over.match.user_) and the standard conversion
6209 sequence from the return type of F1 to the destination type (i.e.,
6210 the type of the entity being initialized) is a better conversion
6211 sequence than the standard conversion sequence from the return type
6212 of F2 to the destination type. */
6214 if (cand1->second_conv)
6216 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6221 /* Check whether we can discard a builtin candidate, either because we
6222 have two identical ones or matching builtin and non-builtin candidates.
6224 (Pedantically in the latter case the builtin which matched the user
6225 function should not be added to the overload set, but we spot it here.
6228 ... the builtin candidates include ...
6229 - do not have the same parameter type list as any non-template
6230 non-member candidate. */
6232 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6233 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6235 for (i = 0; i < len; ++i)
6236 if (!same_type_p (cand1->convs[i]->type,
6237 cand2->convs[i]->type))
6239 if (i == cand1->num_convs)
6241 if (cand1->fn == cand2->fn)
6242 /* Two built-in candidates; arbitrarily pick one. */
6244 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6245 /* cand1 is built-in; prefer cand2. */
6248 /* cand2 is built-in; prefer cand1. */
6253 /* If the two functions are the same (this can happen with declarations
6254 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6255 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6256 && equal_functions (cand1->fn, cand2->fn))
6261 /* Extension: If the worst conversion for one candidate is worse than the
6262 worst conversion for the other, take the first. */
6265 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6266 struct z_candidate *w = 0, *l = 0;
6268 for (i = 0; i < len; ++i)
6270 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6271 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6272 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6273 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6276 winner = 1, w = cand1, l = cand2;
6278 winner = -1, w = cand2, l = cand1;
6284 ISO C++ says that these are ambiguous, even \
6285 though the worst conversion for the first is better than \
6286 the worst conversion for the second:");
6287 print_z_candidate (_("candidate 1:"), w);
6288 print_z_candidate (_("candidate 2:"), l);
6296 gcc_assert (!winner);
6300 /* Given a list of candidates for overloading, find the best one, if any.
6301 This algorithm has a worst case of O(2n) (winner is last), and a best
6302 case of O(n/2) (totally ambiguous); much better than a sorting
6305 static struct z_candidate *
6306 tourney (struct z_candidate *candidates)
6308 struct z_candidate *champ = candidates, *challenger;
6310 int champ_compared_to_predecessor = 0;
6312 /* Walk through the list once, comparing each current champ to the next
6313 candidate, knocking out a candidate or two with each comparison. */
6315 for (challenger = champ->next; challenger; )
6317 fate = joust (champ, challenger, 0);
6319 challenger = challenger->next;
6324 champ = challenger->next;
6327 champ_compared_to_predecessor = 0;
6332 champ_compared_to_predecessor = 1;
6335 challenger = champ->next;
6339 /* Make sure the champ is better than all the candidates it hasn't yet
6340 been compared to. */
6342 for (challenger = candidates;
6344 && !(champ_compared_to_predecessor && challenger->next == champ);
6345 challenger = challenger->next)
6347 fate = joust (champ, challenger, 0);
6355 /* Returns nonzero if things of type FROM can be converted to TO. */
6358 can_convert (tree to, tree from)
6360 return can_convert_arg (to, from, NULL_TREE, LOOKUP_NORMAL);
6363 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6366 can_convert_arg (tree to, tree from, tree arg, int flags)
6372 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6373 p = conversion_obstack_alloc (0);
6375 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6377 ok_p = (t && !t->bad_p);
6379 /* Free all the conversions we allocated. */
6380 obstack_free (&conversion_obstack, p);
6385 /* Like can_convert_arg, but allows dubious conversions as well. */
6388 can_convert_arg_bad (tree to, tree from, tree arg)
6393 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6394 p = conversion_obstack_alloc (0);
6395 /* Try to perform the conversion. */
6396 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6398 /* Free all the conversions we allocated. */
6399 obstack_free (&conversion_obstack, p);
6404 /* Convert EXPR to TYPE. Return the converted expression.
6406 Note that we allow bad conversions here because by the time we get to
6407 this point we are committed to doing the conversion. If we end up
6408 doing a bad conversion, convert_like will complain. */
6411 perform_implicit_conversion (tree type, tree expr)
6416 if (error_operand_p (expr))
6417 return error_mark_node;
6419 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6420 p = conversion_obstack_alloc (0);
6422 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6427 error ("could not convert %qE to %qT", expr, type);
6428 expr = error_mark_node;
6430 else if (processing_template_decl)
6432 /* In a template, we are only concerned about determining the
6433 type of non-dependent expressions, so we do not have to
6434 perform the actual conversion. */
6435 if (TREE_TYPE (expr) != type)
6436 expr = build_nop (type, expr);
6439 expr = convert_like (conv, expr);
6441 /* Free all the conversions we allocated. */
6442 obstack_free (&conversion_obstack, p);
6447 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6448 permitted. If the conversion is valid, the converted expression is
6449 returned. Otherwise, NULL_TREE is returned, except in the case
6450 that TYPE is a class type; in that case, an error is issued. If
6451 C_CAST_P is true, then this direction initialization is taking
6452 place as part of a static_cast being attempted as part of a C-style
6456 perform_direct_initialization_if_possible (tree type,
6463 if (type == error_mark_node || error_operand_p (expr))
6464 return error_mark_node;
6467 If the destination type is a (possibly cv-qualified) class type:
6469 -- If the initialization is direct-initialization ...,
6470 constructors are considered. ... If no constructor applies, or
6471 the overload resolution is ambiguous, the initialization is
6473 if (CLASS_TYPE_P (type))
6475 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6476 build_tree_list (NULL_TREE, expr),
6477 type, LOOKUP_NORMAL);
6478 return build_cplus_new (type, expr);
6481 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6482 p = conversion_obstack_alloc (0);
6484 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6487 if (!conv || conv->bad_p)
6490 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6491 /*issue_conversion_warnings=*/false,
6494 /* Free all the conversions we allocated. */
6495 obstack_free (&conversion_obstack, p);
6500 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6501 is being bound to a temporary. Create and return a new VAR_DECL
6502 with the indicated TYPE; this variable will store the value to
6503 which the reference is bound. */
6506 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6510 /* Create the variable. */
6511 var = create_temporary_var (type);
6513 /* Register the variable. */
6514 if (TREE_STATIC (decl))
6516 /* Namespace-scope or local static; give it a mangled name. */
6519 TREE_STATIC (var) = 1;
6520 name = mangle_ref_init_variable (decl);
6521 DECL_NAME (var) = name;
6522 SET_DECL_ASSEMBLER_NAME (var, name);
6523 var = pushdecl_top_level (var);
6526 /* Create a new cleanup level if necessary. */
6527 maybe_push_cleanup_level (type);
6532 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6533 initializing a variable of that TYPE. If DECL is non-NULL, it is
6534 the VAR_DECL being initialized with the EXPR. (In that case, the
6535 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6536 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6537 return, if *CLEANUP is no longer NULL, it will be an expression
6538 that should be pushed as a cleanup after the returned expression
6539 is used to initialize DECL.
6541 Return the converted expression. */
6544 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6549 if (type == error_mark_node || error_operand_p (expr))
6550 return error_mark_node;
6552 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6553 p = conversion_obstack_alloc (0);
6555 conv = reference_binding (type, TREE_TYPE (expr), expr, LOOKUP_NORMAL);
6556 if (!conv || conv->bad_p)
6558 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6559 && !real_lvalue_p (expr))
6560 error ("invalid initialization of non-const reference of "
6561 "type %qT from a temporary of type %qT",
6562 type, TREE_TYPE (expr));
6564 error ("invalid initialization of reference of type "
6565 "%qT from expression of type %qT", type,
6567 return error_mark_node;
6570 /* If DECL is non-NULL, then this special rule applies:
6574 The temporary to which the reference is bound or the temporary
6575 that is the complete object to which the reference is bound
6576 persists for the lifetime of the reference.
6578 The temporaries created during the evaluation of the expression
6579 initializing the reference, except the temporary to which the
6580 reference is bound, are destroyed at the end of the
6581 full-expression in which they are created.
6583 In that case, we store the converted expression into a new
6584 VAR_DECL in a new scope.
6586 However, we want to be careful not to create temporaries when
6587 they are not required. For example, given:
6590 struct D : public B {};
6594 there is no need to copy the return value from "f"; we can just
6595 extend its lifetime. Similarly, given:
6598 struct T { operator S(); };
6602 we can extend the lifetime of the return value of the conversion
6604 gcc_assert (conv->kind == ck_ref_bind);
6608 tree base_conv_type;
6610 /* Skip over the REF_BIND. */
6611 conv = conv->u.next;
6612 /* If the next conversion is a BASE_CONV, skip that too -- but
6613 remember that the conversion was required. */
6614 if (conv->kind == ck_base)
6616 if (conv->check_copy_constructor_p)
6617 check_constructor_callable (TREE_TYPE (expr), expr);
6618 base_conv_type = conv->type;
6619 conv = conv->u.next;
6622 base_conv_type = NULL_TREE;
6623 /* Perform the remainder of the conversion. */
6624 expr = convert_like_real (conv, expr,
6625 /*fn=*/NULL_TREE, /*argnum=*/0,
6627 /*issue_conversion_warnings=*/true,
6628 /*c_cast_p=*/false);
6629 if (error_operand_p (expr))
6630 expr = error_mark_node;
6633 if (!real_lvalue_p (expr))
6638 /* Create the temporary variable. */
6639 type = TREE_TYPE (expr);
6640 var = make_temporary_var_for_ref_to_temp (decl, type);
6641 layout_decl (var, 0);
6642 /* If the rvalue is the result of a function call it will be
6643 a TARGET_EXPR. If it is some other construct (such as a
6644 member access expression where the underlying object is
6645 itself the result of a function call), turn it into a
6646 TARGET_EXPR here. It is important that EXPR be a
6647 TARGET_EXPR below since otherwise the INIT_EXPR will
6648 attempt to make a bitwise copy of EXPR to initialize
6650 if (TREE_CODE (expr) != TARGET_EXPR)
6651 expr = get_target_expr (expr);
6652 /* Create the INIT_EXPR that will initialize the temporary
6654 init = build2 (INIT_EXPR, type, var, expr);
6655 if (at_function_scope_p ())
6657 add_decl_expr (var);
6658 *cleanup = cxx_maybe_build_cleanup (var);
6660 /* We must be careful to destroy the temporary only
6661 after its initialization has taken place. If the
6662 initialization throws an exception, then the
6663 destructor should not be run. We cannot simply
6664 transform INIT into something like:
6666 (INIT, ({ CLEANUP_STMT; }))
6668 because emit_local_var always treats the
6669 initializer as a full-expression. Thus, the
6670 destructor would run too early; it would run at the
6671 end of initializing the reference variable, rather
6672 than at the end of the block enclosing the
6675 The solution is to pass back a cleanup expression
6676 which the caller is responsible for attaching to
6677 the statement tree. */
6681 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6682 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6683 static_aggregates = tree_cons (NULL_TREE, var,
6686 /* Use its address to initialize the reference variable. */
6687 expr = build_address (var);
6689 expr = convert_to_base (expr,
6690 build_pointer_type (base_conv_type),
6691 /*check_access=*/true,
6693 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6696 /* Take the address of EXPR. */
6697 expr = build_unary_op (ADDR_EXPR, expr, 0);
6698 /* If a BASE_CONV was required, perform it now. */
6700 expr = (perform_implicit_conversion
6701 (build_pointer_type (base_conv_type), expr));
6702 expr = build_nop (type, expr);
6706 /* Perform the conversion. */
6707 expr = convert_like (conv, expr);
6709 /* Free all the conversions we allocated. */
6710 obstack_free (&conversion_obstack, p);
6715 #include "gt-cp-call.h"