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 Free Software Foundation, Inc.
4 Contributed by Michael Tiemann (tiemann@cygnus.com) and
5 modified by Brendan Kehoe (brendan@cygnus.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
22 Boston, MA 02110-1301, USA. */
25 /* High-level class interface. */
29 #include "coretypes.h"
38 #include "diagnostic.h"
43 /* The various kinds of conversion. */
45 typedef enum conversion_kind {
59 /* The rank of the conversion. Order of the enumerals matters; better
60 conversions should come earlier in the list. */
62 typedef enum conversion_rank {
73 /* An implicit conversion sequence, in the sense of [over.best.ics].
74 The first conversion to be performed is at the end of the chain.
75 That conversion is always a cr_identity conversion. */
77 typedef struct conversion conversion;
79 /* The kind of conversion represented by this step. */
81 /* The rank of this conversion. */
83 BOOL_BITFIELD user_conv_p : 1;
84 BOOL_BITFIELD ellipsis_p : 1;
85 BOOL_BITFIELD this_p : 1;
86 BOOL_BITFIELD bad_p : 1;
87 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
88 temporary should be created to hold the result of the
90 BOOL_BITFIELD need_temporary_p : 1;
91 /* If KIND is ck_identity or ck_base_conv, true to indicate that the
92 copy constructor must be accessible, even though it is not being
94 BOOL_BITFIELD check_copy_constructor_p : 1;
95 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
96 from a pointer-to-derived to pointer-to-base is being performed. */
97 BOOL_BITFIELD base_p : 1;
98 /* The type of the expression resulting from the conversion. */
101 /* The next conversion in the chain. Since the conversions are
102 arranged from outermost to innermost, the NEXT conversion will
103 actually be performed before this conversion. This variant is
104 used only when KIND is neither ck_identity nor ck_ambig. */
106 /* The expression at the beginning of the conversion chain. This
107 variant is used only if KIND is ck_identity or ck_ambig. */
110 /* The function candidate corresponding to this conversion
111 sequence. This field is only used if KIND is ck_user. */
112 struct z_candidate *cand;
115 #define CONVERSION_RANK(NODE) \
116 ((NODE)->bad_p ? cr_bad \
117 : (NODE)->ellipsis_p ? cr_ellipsis \
118 : (NODE)->user_conv_p ? cr_user \
121 static struct obstack conversion_obstack;
122 static bool conversion_obstack_initialized;
124 static struct z_candidate * tourney (struct z_candidate *);
125 static int equal_functions (tree, tree);
126 static int joust (struct z_candidate *, struct z_candidate *, bool);
127 static int compare_ics (conversion *, conversion *);
128 static tree build_over_call (struct z_candidate *, int);
129 static tree build_java_interface_fn_ref (tree, tree);
130 #define convert_like(CONV, EXPR) \
131 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
132 /*issue_conversion_warnings=*/true, \
134 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
135 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
136 /*issue_conversion_warnings=*/true, \
138 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
140 static void op_error (enum tree_code, enum tree_code, tree, tree,
142 static tree build_object_call (tree, tree);
143 static tree resolve_args (tree);
144 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
145 static void print_z_candidate (const char *, struct z_candidate *);
146 static void print_z_candidates (struct z_candidate *);
147 static tree build_this (tree);
148 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
149 static bool any_strictly_viable (struct z_candidate *);
150 static struct z_candidate *add_template_candidate
151 (struct z_candidate **, tree, tree, tree, tree, tree,
152 tree, tree, int, unification_kind_t);
153 static struct z_candidate *add_template_candidate_real
154 (struct z_candidate **, tree, tree, tree, tree, tree,
155 tree, tree, int, tree, unification_kind_t);
156 static struct z_candidate *add_template_conv_candidate
157 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
158 static void add_builtin_candidates
159 (struct z_candidate **, enum tree_code, enum tree_code,
161 static void add_builtin_candidate
162 (struct z_candidate **, enum tree_code, enum tree_code,
163 tree, tree, tree, tree *, tree *, int);
164 static bool is_complete (tree);
165 static void build_builtin_candidate
166 (struct z_candidate **, tree, tree, tree, tree *, tree *,
168 static struct z_candidate *add_conv_candidate
169 (struct z_candidate **, tree, tree, tree, tree, tree);
170 static struct z_candidate *add_function_candidate
171 (struct z_candidate **, tree, tree, tree, tree, tree, int);
172 static conversion *implicit_conversion (tree, tree, tree, bool, int);
173 static conversion *standard_conversion (tree, tree, tree, bool, int);
174 static conversion *reference_binding (tree, tree, tree, bool, int);
175 static conversion *build_conv (conversion_kind, tree, conversion *);
176 static bool is_subseq (conversion *, conversion *);
177 static tree maybe_handle_ref_bind (conversion **);
178 static void maybe_handle_implicit_object (conversion **);
179 static struct z_candidate *add_candidate
180 (struct z_candidate **, tree, tree, size_t,
181 conversion **, tree, tree, int);
182 static tree source_type (conversion *);
183 static void add_warning (struct z_candidate *, struct z_candidate *);
184 static bool reference_related_p (tree, tree);
185 static bool reference_compatible_p (tree, tree);
186 static conversion *convert_class_to_reference (tree, tree, tree);
187 static conversion *direct_reference_binding (tree, conversion *);
188 static bool promoted_arithmetic_type_p (tree);
189 static conversion *conditional_conversion (tree, tree);
190 static char *name_as_c_string (tree, tree, bool *);
191 static tree call_builtin_trap (void);
192 static tree prep_operand (tree);
193 static void add_candidates (tree, tree, tree, bool, tree, tree,
194 int, struct z_candidate **);
195 static conversion *merge_conversion_sequences (conversion *, conversion *);
196 static bool magic_varargs_p (tree);
197 typedef void (*diagnostic_fn_t) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
198 static tree build_temp (tree, tree, int, diagnostic_fn_t *);
199 static void check_constructor_callable (tree, tree);
201 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
202 NAME can take many forms... */
205 check_dtor_name (tree basetype, tree name)
207 /* Just accept something we've already complained about. */
208 if (name == error_mark_node)
211 if (TREE_CODE (name) == TYPE_DECL)
212 name = TREE_TYPE (name);
213 else if (TYPE_P (name))
215 else if (TREE_CODE (name) == IDENTIFIER_NODE)
217 if ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
218 || (TREE_CODE (basetype) == ENUMERAL_TYPE
219 && name == TYPE_IDENTIFIER (basetype)))
222 name = get_type_value (name);
228 template <class T> struct S { ~S(); };
232 NAME will be a class template. */
233 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
239 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
242 /* We want the address of a function or method. We avoid creating a
243 pointer-to-member function. */
246 build_addr_func (tree function)
248 tree type = TREE_TYPE (function);
250 /* We have to do these by hand to avoid real pointer to member
252 if (TREE_CODE (type) == METHOD_TYPE)
254 if (TREE_CODE (function) == OFFSET_REF)
256 tree object = build_address (TREE_OPERAND (function, 0));
257 return get_member_function_from_ptrfunc (&object,
258 TREE_OPERAND (function, 1));
260 function = build_address (function);
263 function = decay_conversion (function);
268 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
269 POINTER_TYPE to those. Note, pointer to member function types
270 (TYPE_PTRMEMFUNC_P) must be handled by our callers. */
273 build_call (tree function, tree parms)
275 int is_constructor = 0;
282 function = build_addr_func (function);
284 /* APPLE LOCAL blocks 6040305 */
285 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)) || TREE_CODE (TREE_TYPE (function)) == BLOCK_POINTER_TYPE);
286 fntype = TREE_TYPE (TREE_TYPE (function));
287 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
288 || TREE_CODE (fntype) == METHOD_TYPE);
289 result_type = TREE_TYPE (fntype);
291 if (TREE_CODE (function) == ADDR_EXPR
292 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
294 decl = TREE_OPERAND (function, 0);
295 if (!TREE_USED (decl))
297 /* We invoke build_call directly for several library
298 functions. These may have been declared normally if
299 we're building libgcc, so we can't just check
301 gcc_assert (DECL_ARTIFICIAL (decl)
302 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
310 /* We check both the decl and the type; a function may be known not to
311 throw without being declared throw(). */
312 nothrow = ((decl && TREE_NOTHROW (decl))
313 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
315 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
316 current_function_returns_abnormally = 1;
318 if (decl && TREE_DEPRECATED (decl))
319 warn_deprecated_use (decl);
320 require_complete_eh_spec_types (fntype, decl);
322 if (decl && DECL_CONSTRUCTOR_P (decl))
325 /* Don't pass empty class objects by value. This is useful
326 for tags in STL, which are used to control overload resolution.
327 We don't need to handle other cases of copying empty classes. */
328 if (! decl || ! DECL_BUILT_IN (decl))
329 for (tmp = parms; tmp; tmp = TREE_CHAIN (tmp))
330 if (is_empty_class (TREE_TYPE (TREE_VALUE (tmp)))
331 && ! TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (tmp))))
333 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (TREE_VALUE (tmp)));
334 TREE_VALUE (tmp) = build2 (COMPOUND_EXPR, TREE_TYPE (t),
335 TREE_VALUE (tmp), t);
338 function = build3 (CALL_EXPR, result_type, function, parms, NULL_TREE);
339 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
340 TREE_NOTHROW (function) = nothrow;
345 /* Build something of the form ptr->method (args)
346 or object.method (args). This can also build
347 calls to constructors, and find friends.
349 Member functions always take their class variable
352 INSTANCE is a class instance.
354 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
356 PARMS help to figure out what that NAME really refers to.
358 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
359 down to the real instance type to use for access checking. We need this
360 information to get protected accesses correct.
362 FLAGS is the logical disjunction of zero or more LOOKUP_
363 flags. See cp-tree.h for more info.
365 If this is all OK, calls build_function_call with the resolved
368 This function must also handle being called to perform
369 initialization, promotion/coercion of arguments, and
370 instantiation of default parameters.
372 Note that NAME may refer to an instance variable name. If
373 `operator()()' is defined for the type of that field, then we return
376 /* New overloading code. */
378 typedef struct z_candidate z_candidate;
380 typedef struct candidate_warning candidate_warning;
381 struct candidate_warning {
383 candidate_warning *next;
387 /* The FUNCTION_DECL that will be called if this candidate is
388 selected by overload resolution. */
390 /* The arguments to use when calling this function. */
392 /* The implicit conversion sequences for each of the arguments to
395 /* The number of implicit conversion sequences. */
397 /* If FN is a user-defined conversion, the standard conversion
398 sequence from the type returned by FN to the desired destination
400 conversion *second_conv;
402 /* If FN is a member function, the binfo indicating the path used to
403 qualify the name of FN at the call site. This path is used to
404 determine whether or not FN is accessible if it is selected by
405 overload resolution. The DECL_CONTEXT of FN will always be a
406 (possibly improper) base of this binfo. */
408 /* If FN is a non-static member function, the binfo indicating the
409 subobject to which the `this' pointer should be converted if FN
410 is selected by overload resolution. The type pointed to the by
411 the `this' pointer must correspond to the most derived class
412 indicated by the CONVERSION_PATH. */
413 tree conversion_path;
415 candidate_warning *warnings;
419 /* Returns true iff T is a null pointer constant in the sense of
423 null_ptr_cst_p (tree t)
427 A null pointer constant is an integral constant expression
428 (_expr.const_) rvalue of integer type that evaluates to zero. */
429 t = integral_constant_value (t);
432 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t))
435 if (!TREE_CONSTANT_OVERFLOW (t))
441 /* Returns nonzero if PARMLIST consists of only default parms and/or
445 sufficient_parms_p (tree parmlist)
447 for (; parmlist && parmlist != void_list_node;
448 parmlist = TREE_CHAIN (parmlist))
449 if (!TREE_PURPOSE (parmlist))
454 /* Allocate N bytes of memory from the conversion obstack. The memory
455 is zeroed before being returned. */
458 conversion_obstack_alloc (size_t n)
461 if (!conversion_obstack_initialized)
463 gcc_obstack_init (&conversion_obstack);
464 conversion_obstack_initialized = true;
466 p = obstack_alloc (&conversion_obstack, n);
471 /* Dynamically allocate a conversion. */
474 alloc_conversion (conversion_kind kind)
477 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
482 #ifdef ENABLE_CHECKING
484 /* Make sure that all memory on the conversion obstack has been
488 validate_conversion_obstack (void)
490 if (conversion_obstack_initialized)
491 gcc_assert ((obstack_next_free (&conversion_obstack)
492 == obstack_base (&conversion_obstack)));
495 #endif /* ENABLE_CHECKING */
497 /* Dynamically allocate an array of N conversions. */
500 alloc_conversions (size_t n)
502 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
506 build_conv (conversion_kind code, tree type, conversion *from)
509 conversion_rank rank = CONVERSION_RANK (from);
511 /* We can't use buildl1 here because CODE could be USER_CONV, which
512 takes two arguments. In that case, the caller is responsible for
513 filling in the second argument. */
514 t = alloc_conversion (code);
537 t->user_conv_p = (code == ck_user || from->user_conv_p);
538 t->bad_p = from->bad_p;
543 /* Build a representation of the identity conversion from EXPR to
544 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
547 build_identity_conv (tree type, tree expr)
551 c = alloc_conversion (ck_identity);
558 /* Converting from EXPR to TYPE was ambiguous in the sense that there
559 were multiple user-defined conversions to accomplish the job.
560 Build a conversion that indicates that ambiguity. */
563 build_ambiguous_conv (tree type, tree expr)
567 c = alloc_conversion (ck_ambig);
575 strip_top_quals (tree t)
577 if (TREE_CODE (t) == ARRAY_TYPE)
579 return cp_build_qualified_type (t, 0);
582 /* Returns the standard conversion path (see [conv]) from type FROM to type
583 TO, if any. For proper handling of null pointer constants, you must
584 also pass the expression EXPR to convert from. If C_CAST_P is true,
585 this conversion is coming from a C-style cast. */
588 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
591 enum tree_code fcode, tcode;
593 bool fromref = false;
595 to = non_reference (to);
596 if (TREE_CODE (from) == REFERENCE_TYPE)
599 from = TREE_TYPE (from);
601 to = strip_top_quals (to);
602 from = strip_top_quals (from);
604 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
605 && expr && type_unknown_p (expr))
607 expr = instantiate_type (to, expr, tf_conv);
608 if (expr == error_mark_node)
610 from = TREE_TYPE (expr);
613 fcode = TREE_CODE (from);
614 tcode = TREE_CODE (to);
616 conv = build_identity_conv (from, expr);
617 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
619 from = type_decays_to (from);
620 fcode = TREE_CODE (from);
621 conv = build_conv (ck_lvalue, from, conv);
623 else if (fromref || (expr && lvalue_p (expr)))
628 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
631 from = strip_top_quals (bitfield_type);
632 fcode = TREE_CODE (from);
635 conv = build_conv (ck_rvalue, from, conv);
638 /* Allow conversion between `__complex__' data types. */
639 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
641 /* The standard conversion sequence to convert FROM to TO is
642 the standard conversion sequence to perform componentwise
644 conversion *part_conv = standard_conversion
645 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
649 conv = build_conv (part_conv->kind, to, conv);
650 conv->rank = part_conv->rank;
658 if (same_type_p (from, to))
661 /* APPLE LOCAL blocks 6040305 (ck) */
662 if ((tcode == POINTER_TYPE || tcode == BLOCK_POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
663 && expr && null_ptr_cst_p (expr))
664 conv = build_conv (ck_std, to, conv);
665 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
666 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
668 /* For backwards brain damage compatibility, allow interconversion of
669 pointers and integers with a pedwarn. */
670 conv = build_conv (ck_std, to, conv);
673 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
675 /* For backwards brain damage compatibility, allow interconversion of
676 enums and integers with a pedwarn. */
677 conv = build_conv (ck_std, to, conv);
680 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
681 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
686 if (tcode == POINTER_TYPE
687 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
690 else if (VOID_TYPE_P (TREE_TYPE (to))
691 && !TYPE_PTRMEM_P (from)
692 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
694 from = build_pointer_type
695 (cp_build_qualified_type (void_type_node,
696 cp_type_quals (TREE_TYPE (from))));
697 conv = build_conv (ck_ptr, from, conv);
699 else if (TYPE_PTRMEM_P (from))
701 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
702 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
704 if (DERIVED_FROM_P (fbase, tbase)
705 && (same_type_ignoring_top_level_qualifiers_p
706 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
707 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
709 from = build_ptrmem_type (tbase,
710 TYPE_PTRMEM_POINTED_TO_TYPE (from));
711 conv = build_conv (ck_pmem, from, conv);
713 else if (!same_type_p (fbase, tbase))
716 else if (IS_AGGR_TYPE (TREE_TYPE (from))
717 && IS_AGGR_TYPE (TREE_TYPE (to))
720 An rvalue of type "pointer to cv D," where D is a
721 class type, can be converted to an rvalue of type
722 "pointer to cv B," where B is a base class (clause
723 _class.derived_) of D. If B is an inaccessible
724 (clause _class.access_) or ambiguous
725 (_class.member.lookup_) base class of D, a program
726 that necessitates this conversion is ill-formed.
727 Therefore, we use DERIVED_FROM_P, and do not check
728 access or uniqueness. */
729 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))
730 /* If FROM is not yet complete, then we must be parsing
731 the body of a class. We know what's derived from
732 what, but we can't actually perform a
733 derived-to-base conversion. For example, in:
735 struct D : public B {
736 static const int i = sizeof((B*)(D*)0);
739 the D*-to-B* conversion is a reinterpret_cast, not a
741 && COMPLETE_TYPE_P (TREE_TYPE (from)))
744 cp_build_qualified_type (TREE_TYPE (to),
745 cp_type_quals (TREE_TYPE (from)));
746 from = build_pointer_type (from);
747 conv = build_conv (ck_ptr, from, conv);
751 if (tcode == POINTER_TYPE)
753 to_pointee = TREE_TYPE (to);
754 from_pointee = TREE_TYPE (from);
758 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
759 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
762 if (same_type_p (from, to))
764 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
765 /* In a C-style cast, we ignore CV-qualification because we
766 are allowed to perform a static_cast followed by a
768 conv = build_conv (ck_qual, to, conv);
769 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
770 conv = build_conv (ck_qual, to, conv);
771 else if (expr && string_conv_p (to, expr, 0))
772 /* converting from string constant to char *. */
773 conv = build_conv (ck_qual, to, conv);
774 else if (ptr_reasonably_similar (to_pointee, from_pointee))
776 conv = build_conv (ck_ptr, to, conv);
784 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
786 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
787 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
788 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
789 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
791 if (!DERIVED_FROM_P (fbase, tbase)
792 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
793 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
794 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
795 || cp_type_quals (fbase) != cp_type_quals (tbase))
798 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
799 from = build_method_type_directly (from,
801 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
802 from = build_ptrmemfunc_type (build_pointer_type (from));
803 conv = build_conv (ck_pmem, from, conv);
806 else if (tcode == BOOLEAN_TYPE)
810 An rvalue of arithmetic, enumeration, pointer, or pointer to
811 member type can be converted to an rvalue of type bool. */
812 if (ARITHMETIC_TYPE_P (from)
813 || fcode == ENUMERAL_TYPE
814 || fcode == POINTER_TYPE
815 /* APPLE LOCAL blocks 6040305 (cl) */
816 || fcode == BLOCK_POINTER_TYPE
817 || TYPE_PTR_TO_MEMBER_P (from))
819 conv = build_conv (ck_std, to, conv);
820 if (fcode == POINTER_TYPE
821 || TYPE_PTRMEM_P (from)
822 || (TYPE_PTRMEMFUNC_P (from)
823 && conv->rank < cr_pbool))
824 conv->rank = cr_pbool;
830 /* We don't check for ENUMERAL_TYPE here because there are no standard
831 conversions to enum type. */
832 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
833 || tcode == REAL_TYPE)
835 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
837 conv = build_conv (ck_std, to, conv);
839 /* Give this a better rank if it's a promotion. */
840 if (same_type_p (to, type_promotes_to (from))
841 && conv->u.next->rank <= cr_promotion)
842 conv->rank = cr_promotion;
844 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
845 && vector_types_convertible_p (from, to, false))
846 return build_conv (ck_std, to, conv);
847 else if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE)
848 && IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
849 && is_properly_derived_from (from, to))
851 if (conv->kind == ck_rvalue)
853 conv = build_conv (ck_base, to, conv);
854 /* The derived-to-base conversion indicates the initialization
855 of a parameter with base type from an object of a derived
856 type. A temporary object is created to hold the result of
858 conv->need_temporary_p = true;
866 /* Returns nonzero if T1 is reference-related to T2. */
869 reference_related_p (tree t1, tree t2)
871 t1 = TYPE_MAIN_VARIANT (t1);
872 t2 = TYPE_MAIN_VARIANT (t2);
876 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
877 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
879 return (same_type_p (t1, t2)
880 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
881 && DERIVED_FROM_P (t1, t2)));
884 /* APPLE LOCAL begin radar 6029624 */
885 /* Used in objective-c++, same as reference_related_p */
887 objcp_reference_related_p (tree t1, tree t2)
889 return reference_related_p (t1, t2);
891 /* APPLE LOCAL end radar 6029624 */
893 /* Returns nonzero if T1 is reference-compatible with T2. */
896 reference_compatible_p (tree t1, tree t2)
900 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
901 reference-related to T2 and cv1 is the same cv-qualification as,
902 or greater cv-qualification than, cv2. */
903 return (reference_related_p (t1, t2)
904 && at_least_as_qualified_p (t1, t2));
907 /* Determine whether or not the EXPR (of class type S) can be
908 converted to T as in [over.match.ref]. */
911 convert_class_to_reference (tree t, tree s, tree expr)
917 struct z_candidate *candidates;
918 struct z_candidate *cand;
921 conversions = lookup_conversions (s);
927 Assuming that "cv1 T" is the underlying type of the reference
928 being initialized, and "cv S" is the type of the initializer
929 expression, with S a class type, the candidate functions are
932 --The conversion functions of S and its base classes are
933 considered. Those that are not hidden within S and yield type
934 "reference to cv2 T2", where "cv1 T" is reference-compatible
935 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
937 The argument list has one argument, which is the initializer
942 /* Conceptually, we should take the address of EXPR and put it in
943 the argument list. Unfortunately, however, that can result in
944 error messages, which we should not issue now because we are just
945 trying to find a conversion operator. Therefore, we use NULL,
946 cast to the appropriate type. */
947 arglist = build_int_cst (build_pointer_type (s), 0);
948 arglist = build_tree_list (NULL_TREE, arglist);
950 reference_type = build_reference_type (t);
954 tree fns = TREE_VALUE (conversions);
956 for (; fns; fns = OVL_NEXT (fns))
958 tree f = OVL_CURRENT (fns);
959 tree t2 = TREE_TYPE (TREE_TYPE (f));
963 /* If this is a template function, try to get an exact
965 if (TREE_CODE (f) == TEMPLATE_DECL)
967 cand = add_template_candidate (&candidates,
973 TREE_PURPOSE (conversions),
979 /* Now, see if the conversion function really returns
980 an lvalue of the appropriate type. From the
981 point of view of unification, simply returning an
982 rvalue of the right type is good enough. */
984 t2 = TREE_TYPE (TREE_TYPE (f));
985 if (TREE_CODE (t2) != REFERENCE_TYPE
986 || !reference_compatible_p (t, TREE_TYPE (t2)))
988 candidates = candidates->next;
993 else if (TREE_CODE (t2) == REFERENCE_TYPE
994 && reference_compatible_p (t, TREE_TYPE (t2)))
995 cand = add_function_candidate (&candidates, f, s, arglist,
997 TREE_PURPOSE (conversions),
1002 conversion *identity_conv;
1003 /* Build a standard conversion sequence indicating the
1004 binding from the reference type returned by the
1005 function to the desired REFERENCE_TYPE. */
1007 = build_identity_conv (TREE_TYPE (TREE_TYPE
1008 (TREE_TYPE (cand->fn))),
1011 = (direct_reference_binding
1012 (reference_type, identity_conv));
1013 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1016 conversions = TREE_CHAIN (conversions);
1019 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1020 /* If none of the conversion functions worked out, let our caller
1025 cand = tourney (candidates);
1029 /* Now that we know that this is the function we're going to use fix
1030 the dummy first argument. */
1031 cand->args = tree_cons (NULL_TREE,
1033 TREE_CHAIN (cand->args));
1035 /* Build a user-defined conversion sequence representing the
1037 conv = build_conv (ck_user,
1038 TREE_TYPE (TREE_TYPE (cand->fn)),
1039 build_identity_conv (TREE_TYPE (expr), expr));
1042 /* Merge it with the standard conversion sequence from the
1043 conversion function's return type to the desired type. */
1044 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1046 if (cand->viable == -1)
1049 return cand->second_conv;
1052 /* A reference of the indicated TYPE is being bound directly to the
1053 expression represented by the implicit conversion sequence CONV.
1054 Return a conversion sequence for this binding. */
1057 direct_reference_binding (tree type, conversion *conv)
1061 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1062 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1064 t = TREE_TYPE (type);
1068 When a parameter of reference type binds directly
1069 (_dcl.init.ref_) to an argument expression, the implicit
1070 conversion sequence is the identity conversion, unless the
1071 argument expression has a type that is a derived class of the
1072 parameter type, in which case the implicit conversion sequence is
1073 a derived-to-base Conversion.
1075 If the parameter binds directly to the result of applying a
1076 conversion function to the argument expression, the implicit
1077 conversion sequence is a user-defined conversion sequence
1078 (_over.ics.user_), with the second standard conversion sequence
1079 either an identity conversion or, if the conversion function
1080 returns an entity of a type that is a derived class of the
1081 parameter type, a derived-to-base conversion. */
1082 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1084 /* Represent the derived-to-base conversion. */
1085 conv = build_conv (ck_base, t, conv);
1086 /* We will actually be binding to the base-class subobject in
1087 the derived class, so we mark this conversion appropriately.
1088 That way, convert_like knows not to generate a temporary. */
1089 conv->need_temporary_p = false;
1091 return build_conv (ck_ref_bind, type, conv);
1094 /* Returns the conversion path from type FROM to reference type TO for
1095 purposes of reference binding. For lvalue binding, either pass a
1096 reference type to FROM or an lvalue expression to EXPR. If the
1097 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1098 the conversion returned. If C_CAST_P is true, this
1099 conversion is coming from a C-style cast. */
1102 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1104 conversion *conv = NULL;
1105 tree to = TREE_TYPE (rto);
1109 cp_lvalue_kind lvalue_p = clk_none;
1111 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1113 expr = instantiate_type (to, expr, tf_none);
1114 if (expr == error_mark_node)
1116 from = TREE_TYPE (expr);
1119 if (TREE_CODE (from) == REFERENCE_TYPE)
1121 /* Anything with reference type is an lvalue. */
1122 lvalue_p = clk_ordinary;
1123 from = TREE_TYPE (from);
1126 lvalue_p = real_lvalue_p (expr);
1128 /* Figure out whether or not the types are reference-related and
1129 reference compatible. We have do do this after stripping
1130 references from FROM. */
1131 related_p = reference_related_p (to, from);
1132 /* If this is a C cast, first convert to an appropriately qualified
1133 type, so that we can later do a const_cast to the desired type. */
1134 if (related_p && c_cast_p
1135 && !at_least_as_qualified_p (to, from))
1136 to = build_qualified_type (to, cp_type_quals (from));
1137 compatible_p = reference_compatible_p (to, from);
1139 if (lvalue_p && compatible_p)
1143 If the initializer expression
1145 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1146 is reference-compatible with "cv2 T2,"
1148 the reference is bound directly to the initializer expression
1150 conv = build_identity_conv (from, expr);
1151 conv = direct_reference_binding (rto, conv);
1152 if ((lvalue_p & clk_bitfield) != 0
1153 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1154 /* For the purposes of overload resolution, we ignore the fact
1155 this expression is a bitfield or packed field. (In particular,
1156 [over.ics.ref] says specifically that a function with a
1157 non-const reference parameter is viable even if the
1158 argument is a bitfield.)
1160 However, when we actually call the function we must create
1161 a temporary to which to bind the reference. If the
1162 reference is volatile, or isn't const, then we cannot make
1163 a temporary, so we just issue an error when the conversion
1165 conv->need_temporary_p = true;
1169 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1173 If the initializer expression
1175 -- has a class type (i.e., T2 is a class type) can be
1176 implicitly converted to an lvalue of type "cv3 T3," where
1177 "cv1 T1" is reference-compatible with "cv3 T3". (this
1178 conversion is selected by enumerating the applicable
1179 conversion functions (_over.match.ref_) and choosing the
1180 best one through overload resolution. (_over.match_).
1182 the reference is bound to the lvalue result of the conversion
1183 in the second case. */
1184 conv = convert_class_to_reference (to, from, expr);
1189 /* From this point on, we conceptually need temporaries, even if we
1190 elide them. Only the cases above are "direct bindings". */
1191 if (flags & LOOKUP_NO_TEMP_BIND)
1196 When a parameter of reference type is not bound directly to an
1197 argument expression, the conversion sequence is the one required
1198 to convert the argument expression to the underlying type of the
1199 reference according to _over.best.ics_. Conceptually, this
1200 conversion sequence corresponds to copy-initializing a temporary
1201 of the underlying type with the argument expression. Any
1202 difference in top-level cv-qualification is subsumed by the
1203 initialization itself and does not constitute a conversion. */
1207 Otherwise, the reference shall be to a non-volatile const type. */
1208 if (!CP_TYPE_CONST_NON_VOLATILE_P (to))
1213 If the initializer expression is an rvalue, with T2 a class type,
1214 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1215 is bound in one of the following ways:
1217 -- The reference is bound to the object represented by the rvalue
1218 or to a sub-object within that object.
1222 We use the first alternative. The implicit conversion sequence
1223 is supposed to be same as we would obtain by generating a
1224 temporary. Fortunately, if the types are reference compatible,
1225 then this is either an identity conversion or the derived-to-base
1226 conversion, just as for direct binding. */
1227 if (CLASS_TYPE_P (from) && compatible_p)
1229 conv = build_identity_conv (from, expr);
1230 conv = direct_reference_binding (rto, conv);
1231 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1232 conv->u.next->check_copy_constructor_p = true;
1238 Otherwise, a temporary of type "cv1 T1" is created and
1239 initialized from the initializer expression using the rules for a
1240 non-reference copy initialization. If T1 is reference-related to
1241 T2, cv1 must be the same cv-qualification as, or greater
1242 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1243 if (related_p && !at_least_as_qualified_p (to, from))
1246 conv = implicit_conversion (to, from, expr, c_cast_p,
1251 conv = build_conv (ck_ref_bind, rto, conv);
1252 /* This reference binding, unlike those above, requires the
1253 creation of a temporary. */
1254 conv->need_temporary_p = true;
1259 /* Returns the implicit conversion sequence (see [over.ics]) from type
1260 FROM to type TO. The optional expression EXPR may affect the
1261 conversion. FLAGS are the usual overloading flags. Only
1262 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1263 conversion is coming from a C-style cast. */
1266 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1271 if (from == error_mark_node || to == error_mark_node
1272 || expr == error_mark_node)
1275 if (TREE_CODE (to) == REFERENCE_TYPE)
1276 conv = reference_binding (to, from, expr, c_cast_p, flags);
1278 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1283 if (expr != NULL_TREE
1284 && (IS_AGGR_TYPE (from)
1285 || IS_AGGR_TYPE (to))
1286 && (flags & LOOKUP_NO_CONVERSION) == 0)
1288 struct z_candidate *cand;
1290 cand = build_user_type_conversion_1
1291 (to, expr, LOOKUP_ONLYCONVERTING);
1293 conv = cand->second_conv;
1295 /* We used to try to bind a reference to a temporary here, but that
1296 is now handled by the recursive call to this function at the end
1297 of reference_binding. */
1304 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1307 static struct z_candidate *
1308 add_candidate (struct z_candidate **candidates,
1310 size_t num_convs, conversion **convs,
1311 tree access_path, tree conversion_path,
1314 struct z_candidate *cand = (struct z_candidate *)
1315 conversion_obstack_alloc (sizeof (struct z_candidate));
1319 cand->convs = convs;
1320 cand->num_convs = num_convs;
1321 cand->access_path = access_path;
1322 cand->conversion_path = conversion_path;
1323 cand->viable = viable;
1324 cand->next = *candidates;
1330 /* Create an overload candidate for the function or method FN called with
1331 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1332 to implicit_conversion.
1334 CTYPE, if non-NULL, is the type we want to pretend this function
1335 comes from for purposes of overload resolution. */
1337 static struct z_candidate *
1338 add_function_candidate (struct z_candidate **candidates,
1339 tree fn, tree ctype, tree arglist,
1340 tree access_path, tree conversion_path,
1343 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1346 tree parmnode, argnode;
1350 /* At this point we should not see any functions which haven't been
1351 explicitly declared, except for friend functions which will have
1352 been found using argument dependent lookup. */
1353 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1355 /* The `this', `in_chrg' and VTT arguments to constructors are not
1356 considered in overload resolution. */
1357 if (DECL_CONSTRUCTOR_P (fn))
1359 parmlist = skip_artificial_parms_for (fn, parmlist);
1360 orig_arglist = arglist;
1361 arglist = skip_artificial_parms_for (fn, arglist);
1364 orig_arglist = arglist;
1366 len = list_length (arglist);
1367 convs = alloc_conversions (len);
1369 /* 13.3.2 - Viable functions [over.match.viable]
1370 First, to be a viable function, a candidate function shall have enough
1371 parameters to agree in number with the arguments in the list.
1373 We need to check this first; otherwise, checking the ICSes might cause
1374 us to produce an ill-formed template instantiation. */
1376 parmnode = parmlist;
1377 for (i = 0; i < len; ++i)
1379 if (parmnode == NULL_TREE || parmnode == void_list_node)
1381 parmnode = TREE_CHAIN (parmnode);
1384 if (i < len && parmnode)
1387 /* Make sure there are default args for the rest of the parms. */
1388 else if (!sufficient_parms_p (parmnode))
1394 /* Second, for F to be a viable function, there shall exist for each
1395 argument an implicit conversion sequence that converts that argument
1396 to the corresponding parameter of F. */
1398 parmnode = parmlist;
1401 for (i = 0; i < len; ++i)
1403 tree arg = TREE_VALUE (argnode);
1404 tree argtype = lvalue_type (arg);
1408 if (parmnode == void_list_node)
1411 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1412 && ! DECL_CONSTRUCTOR_P (fn));
1416 tree parmtype = TREE_VALUE (parmnode);
1418 /* The type of the implicit object parameter ('this') for
1419 overload resolution is not always the same as for the
1420 function itself; conversion functions are considered to
1421 be members of the class being converted, and functions
1422 introduced by a using-declaration are considered to be
1423 members of the class that uses them.
1425 Since build_over_call ignores the ICS for the `this'
1426 parameter, we can just change the parm type. */
1427 if (ctype && is_this)
1430 = build_qualified_type (ctype,
1431 TYPE_QUALS (TREE_TYPE (parmtype)));
1432 parmtype = build_pointer_type (parmtype);
1435 t = implicit_conversion (parmtype, argtype, arg,
1436 /*c_cast_p=*/false, flags);
1440 t = build_identity_conv (argtype, arg);
1441 t->ellipsis_p = true;
1458 parmnode = TREE_CHAIN (parmnode);
1459 argnode = TREE_CHAIN (argnode);
1463 return add_candidate (candidates, fn, orig_arglist, len, convs,
1464 access_path, conversion_path, viable);
1467 /* Create an overload candidate for the conversion function FN which will
1468 be invoked for expression OBJ, producing a pointer-to-function which
1469 will in turn be called with the argument list ARGLIST, and add it to
1470 CANDIDATES. FLAGS is passed on to implicit_conversion.
1472 Actually, we don't really care about FN; we care about the type it
1473 converts to. There may be multiple conversion functions that will
1474 convert to that type, and we rely on build_user_type_conversion_1 to
1475 choose the best one; so when we create our candidate, we record the type
1476 instead of the function. */
1478 static struct z_candidate *
1479 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1480 tree arglist, tree access_path, tree conversion_path)
1482 tree totype = TREE_TYPE (TREE_TYPE (fn));
1483 int i, len, viable, flags;
1484 tree parmlist, parmnode, argnode;
1487 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1488 parmlist = TREE_TYPE (parmlist);
1489 parmlist = TYPE_ARG_TYPES (parmlist);
1491 len = list_length (arglist) + 1;
1492 convs = alloc_conversions (len);
1493 parmnode = parmlist;
1496 flags = LOOKUP_NORMAL;
1498 /* Don't bother looking up the same type twice. */
1499 if (*candidates && (*candidates)->fn == totype)
1502 for (i = 0; i < len; ++i)
1504 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1505 tree argtype = lvalue_type (arg);
1509 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1511 else if (parmnode == void_list_node)
1514 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1515 /*c_cast_p=*/false, flags);
1518 t = build_identity_conv (argtype, arg);
1519 t->ellipsis_p = true;
1533 parmnode = TREE_CHAIN (parmnode);
1534 argnode = TREE_CHAIN (argnode);
1540 if (!sufficient_parms_p (parmnode))
1543 return add_candidate (candidates, totype, arglist, len, convs,
1544 access_path, conversion_path, viable);
1548 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1549 tree type1, tree type2, tree *args, tree *argtypes,
1561 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1562 convs = alloc_conversions (num_convs);
1564 for (i = 0; i < 2; ++i)
1569 t = implicit_conversion (types[i], argtypes[i], args[i],
1570 /*c_cast_p=*/false, flags);
1574 /* We need something for printing the candidate. */
1575 t = build_identity_conv (types[i], NULL_TREE);
1582 /* For COND_EXPR we rearranged the arguments; undo that now. */
1585 convs[2] = convs[1];
1586 convs[1] = convs[0];
1587 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1588 /*c_cast_p=*/false, flags);
1595 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1597 /*access_path=*/NULL_TREE,
1598 /*conversion_path=*/NULL_TREE,
1603 is_complete (tree t)
1605 return COMPLETE_TYPE_P (complete_type (t));
1608 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1611 promoted_arithmetic_type_p (tree type)
1615 In this section, the term promoted integral type is used to refer
1616 to those integral types which are preserved by integral promotion
1617 (including e.g. int and long but excluding e.g. char).
1618 Similarly, the term promoted arithmetic type refers to promoted
1619 integral types plus floating types. */
1620 return ((INTEGRAL_TYPE_P (type)
1621 && same_type_p (type_promotes_to (type), type))
1622 || TREE_CODE (type) == REAL_TYPE);
1625 /* Create any builtin operator overload candidates for the operator in
1626 question given the converted operand types TYPE1 and TYPE2. The other
1627 args are passed through from add_builtin_candidates to
1628 build_builtin_candidate.
1630 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1631 If CODE is requires candidates operands of the same type of the kind
1632 of which TYPE1 and TYPE2 are, we add both candidates
1633 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1636 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1637 enum tree_code code2, tree fnname, tree type1,
1638 tree type2, tree *args, tree *argtypes, int flags)
1642 case POSTINCREMENT_EXPR:
1643 case POSTDECREMENT_EXPR:
1644 args[1] = integer_zero_node;
1645 type2 = integer_type_node;
1654 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1655 and VQ is either volatile or empty, there exist candidate operator
1656 functions of the form
1657 VQ T& operator++(VQ T&);
1658 T operator++(VQ T&, int);
1659 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1660 type other than bool, and VQ is either volatile or empty, there exist
1661 candidate operator functions of the form
1662 VQ T& operator--(VQ T&);
1663 T operator--(VQ T&, int);
1664 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1665 complete object type, and VQ is either volatile or empty, there exist
1666 candidate operator functions of the form
1667 T*VQ& operator++(T*VQ&);
1668 T*VQ& operator--(T*VQ&);
1669 T* operator++(T*VQ&, int);
1670 T* operator--(T*VQ&, int); */
1672 case POSTDECREMENT_EXPR:
1673 case PREDECREMENT_EXPR:
1674 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1676 case POSTINCREMENT_EXPR:
1677 case PREINCREMENT_EXPR:
1678 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1680 type1 = build_reference_type (type1);
1685 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1686 exist candidate operator functions of the form
1690 8 For every function type T, there exist candidate operator functions of
1692 T& operator*(T*); */
1695 if (TREE_CODE (type1) == POINTER_TYPE
1696 && (TYPE_PTROB_P (type1)
1697 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1701 /* 9 For every type T, there exist candidate operator functions of the form
1704 10For every promoted arithmetic type T, there exist candidate operator
1705 functions of the form
1709 case UNARY_PLUS_EXPR: /* unary + */
1710 if (TREE_CODE (type1) == POINTER_TYPE)
1713 if (ARITHMETIC_TYPE_P (type1))
1717 /* 11For every promoted integral type T, there exist candidate operator
1718 functions of the form
1722 if (INTEGRAL_TYPE_P (type1))
1726 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1727 is the same type as C2 or is a derived class of C2, T is a complete
1728 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1729 there exist candidate operator functions of the form
1730 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1731 where CV12 is the union of CV1 and CV2. */
1734 if (TREE_CODE (type1) == POINTER_TYPE
1735 && TYPE_PTR_TO_MEMBER_P (type2))
1737 tree c1 = TREE_TYPE (type1);
1738 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1740 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1741 && (TYPE_PTRMEMFUNC_P (type2)
1742 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1747 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1748 didate operator functions of the form
1753 bool operator<(L, R);
1754 bool operator>(L, R);
1755 bool operator<=(L, R);
1756 bool operator>=(L, R);
1757 bool operator==(L, R);
1758 bool operator!=(L, R);
1759 where LR is the result of the usual arithmetic conversions between
1762 14For every pair of types T and I, where T is a cv-qualified or cv-
1763 unqualified complete object type and I is a promoted integral type,
1764 there exist candidate operator functions of the form
1765 T* operator+(T*, I);
1766 T& operator[](T*, I);
1767 T* operator-(T*, I);
1768 T* operator+(I, T*);
1769 T& operator[](I, T*);
1771 15For every T, where T is a pointer to complete object type, there exist
1772 candidate operator functions of the form112)
1773 ptrdiff_t operator-(T, T);
1775 16For every pointer or enumeration type T, there exist candidate operator
1776 functions of the form
1777 bool operator<(T, T);
1778 bool operator>(T, T);
1779 bool operator<=(T, T);
1780 bool operator>=(T, T);
1781 bool operator==(T, T);
1782 bool operator!=(T, T);
1784 17For every pointer to member type T, there exist candidate operator
1785 functions of the form
1786 bool operator==(T, T);
1787 bool operator!=(T, T); */
1790 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1792 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1794 type2 = ptrdiff_type_node;
1798 case TRUNC_DIV_EXPR:
1799 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1805 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1806 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1808 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1813 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1825 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1827 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1829 if (TREE_CODE (type1) == ENUMERAL_TYPE
1830 && TREE_CODE (type2) == ENUMERAL_TYPE)
1832 if (TYPE_PTR_P (type1)
1833 && null_ptr_cst_p (args[1])
1834 && !uses_template_parms (type1))
1839 if (null_ptr_cst_p (args[0])
1840 && TYPE_PTR_P (type2)
1841 && !uses_template_parms (type2))
1849 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1852 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1854 type1 = ptrdiff_type_node;
1857 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1859 type2 = ptrdiff_type_node;
1864 /* 18For every pair of promoted integral types L and R, there exist candi-
1865 date operator functions of the form
1872 where LR is the result of the usual arithmetic conversions between
1875 case TRUNC_MOD_EXPR:
1881 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1885 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1886 type, VQ is either volatile or empty, and R is a promoted arithmetic
1887 type, there exist candidate operator functions of the form
1888 VQ L& operator=(VQ L&, R);
1889 VQ L& operator*=(VQ L&, R);
1890 VQ L& operator/=(VQ L&, R);
1891 VQ L& operator+=(VQ L&, R);
1892 VQ L& operator-=(VQ L&, R);
1894 20For every pair T, VQ), where T is any type and VQ is either volatile
1895 or empty, there exist candidate operator functions of the form
1896 T*VQ& operator=(T*VQ&, T*);
1898 21For every pair T, VQ), where T is a pointer to member type and VQ is
1899 either volatile or empty, there exist candidate operator functions of
1901 VQ T& operator=(VQ T&, T);
1903 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1904 unqualified complete object type, VQ is either volatile or empty, and
1905 I is a promoted integral type, there exist candidate operator func-
1907 T*VQ& operator+=(T*VQ&, I);
1908 T*VQ& operator-=(T*VQ&, I);
1910 23For every triple L, VQ, R), where L is an integral or enumeration
1911 type, VQ is either volatile or empty, and R is a promoted integral
1912 type, there exist candidate operator functions of the form
1914 VQ L& operator%=(VQ L&, R);
1915 VQ L& operator<<=(VQ L&, R);
1916 VQ L& operator>>=(VQ L&, R);
1917 VQ L& operator&=(VQ L&, R);
1918 VQ L& operator^=(VQ L&, R);
1919 VQ L& operator|=(VQ L&, R); */
1926 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1928 type2 = ptrdiff_type_node;
1932 case TRUNC_DIV_EXPR:
1933 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1937 case TRUNC_MOD_EXPR:
1943 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1948 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1950 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1951 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1952 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1953 || ((TYPE_PTRMEMFUNC_P (type1)
1954 || TREE_CODE (type1) == POINTER_TYPE)
1955 && null_ptr_cst_p (args[1])))
1965 type1 = build_reference_type (type1);
1971 For every pair of promoted arithmetic types L and R, there
1972 exist candidate operator functions of the form
1974 LR operator?(bool, L, R);
1976 where LR is the result of the usual arithmetic conversions
1977 between types L and R.
1979 For every type T, where T is a pointer or pointer-to-member
1980 type, there exist candidate operator functions of the form T
1981 operator?(bool, T, T); */
1983 if (promoted_arithmetic_type_p (type1)
1984 && promoted_arithmetic_type_p (type2))
1988 /* Otherwise, the types should be pointers. */
1989 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
1990 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
1993 /* We don't check that the two types are the same; the logic
1994 below will actually create two candidates; one in which both
1995 parameter types are TYPE1, and one in which both parameter
2003 /* If we're dealing with two pointer types or two enumeral types,
2004 we need candidates for both of them. */
2005 if (type2 && !same_type_p (type1, type2)
2006 && TREE_CODE (type1) == TREE_CODE (type2)
2007 && (TREE_CODE (type1) == REFERENCE_TYPE
2008 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2009 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2010 || TYPE_PTRMEMFUNC_P (type1)
2011 || IS_AGGR_TYPE (type1)
2012 || TREE_CODE (type1) == ENUMERAL_TYPE))
2014 build_builtin_candidate
2015 (candidates, fnname, type1, type1, args, argtypes, flags);
2016 build_builtin_candidate
2017 (candidates, fnname, type2, type2, args, argtypes, flags);
2021 build_builtin_candidate
2022 (candidates, fnname, type1, type2, args, argtypes, flags);
2026 type_decays_to (tree type)
2028 if (TREE_CODE (type) == ARRAY_TYPE)
2029 return build_pointer_type (TREE_TYPE (type));
2030 if (TREE_CODE (type) == FUNCTION_TYPE)
2031 return build_pointer_type (type);
2035 /* There are three conditions of builtin candidates:
2037 1) bool-taking candidates. These are the same regardless of the input.
2038 2) pointer-pair taking candidates. These are generated for each type
2039 one of the input types converts to.
2040 3) arithmetic candidates. According to the standard, we should generate
2041 all of these, but I'm trying not to...
2043 Here we generate a superset of the possible candidates for this particular
2044 case. That is a subset of the full set the standard defines, plus some
2045 other cases which the standard disallows. add_builtin_candidate will
2046 filter out the invalid set. */
2049 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2050 enum tree_code code2, tree fnname, tree *args,
2055 tree type, argtypes[3];
2056 /* TYPES[i] is the set of possible builtin-operator parameter types
2057 we will consider for the Ith argument. These are represented as
2058 a TREE_LIST; the TREE_VALUE of each node is the potential
2062 for (i = 0; i < 3; ++i)
2065 argtypes[i] = lvalue_type (args[i]);
2067 argtypes[i] = NULL_TREE;
2072 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2073 and VQ is either volatile or empty, there exist candidate operator
2074 functions of the form
2075 VQ T& operator++(VQ T&); */
2077 case POSTINCREMENT_EXPR:
2078 case PREINCREMENT_EXPR:
2079 case POSTDECREMENT_EXPR:
2080 case PREDECREMENT_EXPR:
2085 /* 24There also exist candidate operator functions of the form
2086 bool operator!(bool);
2087 bool operator&&(bool, bool);
2088 bool operator||(bool, bool); */
2090 case TRUTH_NOT_EXPR:
2091 build_builtin_candidate
2092 (candidates, fnname, boolean_type_node,
2093 NULL_TREE, args, argtypes, flags);
2096 case TRUTH_ORIF_EXPR:
2097 case TRUTH_ANDIF_EXPR:
2098 build_builtin_candidate
2099 (candidates, fnname, boolean_type_node,
2100 boolean_type_node, args, argtypes, flags);
2122 types[0] = types[1] = NULL_TREE;
2124 for (i = 0; i < 2; ++i)
2128 else if (IS_AGGR_TYPE (argtypes[i]))
2132 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2135 convs = lookup_conversions (argtypes[i]);
2137 if (code == COND_EXPR)
2139 if (real_lvalue_p (args[i]))
2140 types[i] = tree_cons
2141 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2143 types[i] = tree_cons
2144 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2150 for (; convs; convs = TREE_CHAIN (convs))
2152 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2155 && (TREE_CODE (type) != REFERENCE_TYPE
2156 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2159 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2160 types[i] = tree_cons (NULL_TREE, type, types[i]);
2162 type = non_reference (type);
2163 if (i != 0 || ! ref1)
2165 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2166 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2167 types[i] = tree_cons (NULL_TREE, type, types[i]);
2168 if (INTEGRAL_TYPE_P (type))
2169 type = type_promotes_to (type);
2172 if (! value_member (type, types[i]))
2173 types[i] = tree_cons (NULL_TREE, type, types[i]);
2178 if (code == COND_EXPR && real_lvalue_p (args[i]))
2179 types[i] = tree_cons
2180 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2181 type = non_reference (argtypes[i]);
2182 if (i != 0 || ! ref1)
2184 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2185 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2186 types[i] = tree_cons (NULL_TREE, type, types[i]);
2187 if (INTEGRAL_TYPE_P (type))
2188 type = type_promotes_to (type);
2190 types[i] = tree_cons (NULL_TREE, type, types[i]);
2194 /* Run through the possible parameter types of both arguments,
2195 creating candidates with those parameter types. */
2196 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2199 for (type = types[1]; type; type = TREE_CHAIN (type))
2200 add_builtin_candidate
2201 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2202 TREE_VALUE (type), args, argtypes, flags);
2204 add_builtin_candidate
2205 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2206 NULL_TREE, args, argtypes, flags);
2211 /* If TMPL can be successfully instantiated as indicated by
2212 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2214 TMPL is the template. EXPLICIT_TARGS are any explicit template
2215 arguments. ARGLIST is the arguments provided at the call-site.
2216 The RETURN_TYPE is the desired type for conversion operators. If
2217 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2218 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2219 add_conv_candidate. */
2221 static struct z_candidate*
2222 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2223 tree ctype, tree explicit_targs, tree arglist,
2224 tree return_type, tree access_path,
2225 tree conversion_path, int flags, tree obj,
2226 unification_kind_t strict)
2228 int ntparms = DECL_NTPARMS (tmpl);
2229 tree targs = make_tree_vec (ntparms);
2230 tree args_without_in_chrg = arglist;
2231 struct z_candidate *cand;
2235 /* We don't do deduction on the in-charge parameter, the VTT
2236 parameter or 'this'. */
2237 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2238 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2240 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2241 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2242 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2243 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2245 i = fn_type_unification (tmpl, explicit_targs, targs,
2246 args_without_in_chrg,
2247 return_type, strict, flags);
2252 fn = instantiate_template (tmpl, targs, tf_none);
2253 if (fn == error_mark_node)
2258 A member function template is never instantiated to perform the
2259 copy of a class object to an object of its class type.
2261 It's a little unclear what this means; the standard explicitly
2262 does allow a template to be used to copy a class. For example,
2267 template <class T> A(const T&);
2270 void g () { A a (f ()); }
2272 the member template will be used to make the copy. The section
2273 quoted above appears in the paragraph that forbids constructors
2274 whose only parameter is (a possibly cv-qualified variant of) the
2275 class type, and a logical interpretation is that the intent was
2276 to forbid the instantiation of member templates which would then
2278 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2280 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2281 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2286 if (obj != NULL_TREE)
2287 /* Aha, this is a conversion function. */
2288 cand = add_conv_candidate (candidates, fn, obj, access_path,
2289 conversion_path, arglist);
2291 cand = add_function_candidate (candidates, fn, ctype,
2292 arglist, access_path,
2293 conversion_path, flags);
2294 if (DECL_TI_TEMPLATE (fn) != tmpl)
2295 /* This situation can occur if a member template of a template
2296 class is specialized. Then, instantiate_template might return
2297 an instantiation of the specialization, in which case the
2298 DECL_TI_TEMPLATE field will point at the original
2299 specialization. For example:
2301 template <class T> struct S { template <class U> void f(U);
2302 template <> void f(int) {}; };
2306 Here, TMPL will be template <class U> S<double>::f(U).
2307 And, instantiate template will give us the specialization
2308 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2309 for this will point at template <class T> template <> S<T>::f(int),
2310 so that we can find the definition. For the purposes of
2311 overload resolution, however, we want the original TMPL. */
2312 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2314 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2320 static struct z_candidate *
2321 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2322 tree explicit_targs, tree arglist, tree return_type,
2323 tree access_path, tree conversion_path, int flags,
2324 unification_kind_t strict)
2327 add_template_candidate_real (candidates, tmpl, ctype,
2328 explicit_targs, arglist, return_type,
2329 access_path, conversion_path,
2330 flags, NULL_TREE, strict);
2334 static struct z_candidate *
2335 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2336 tree obj, tree arglist, tree return_type,
2337 tree access_path, tree conversion_path)
2340 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2341 arglist, return_type, access_path,
2342 conversion_path, 0, obj, DEDUCE_CONV);
2345 /* The CANDS are the set of candidates that were considered for
2346 overload resolution. Return the set of viable candidates. If none
2347 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2348 is true if a candidate should be considered viable only if it is
2351 static struct z_candidate*
2352 splice_viable (struct z_candidate *cands,
2356 struct z_candidate *viable;
2357 struct z_candidate **last_viable;
2358 struct z_candidate **cand;
2361 last_viable = &viable;
2362 *any_viable_p = false;
2367 struct z_candidate *c = *cand;
2368 if (strict_p ? c->viable == 1 : c->viable)
2373 last_viable = &c->next;
2374 *any_viable_p = true;
2380 return viable ? viable : cands;
2384 any_strictly_viable (struct z_candidate *cands)
2386 for (; cands; cands = cands->next)
2387 if (cands->viable == 1)
2392 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2393 words, it is about to become the "this" pointer for a member
2394 function call. Take the address of the object. */
2397 build_this (tree obj)
2399 /* In a template, we are only concerned about the type of the
2400 expression, so we can take a shortcut. */
2401 if (processing_template_decl)
2402 return build_address (obj);
2404 return build_unary_op (ADDR_EXPR, obj, 0);
2407 /* Returns true iff functions are equivalent. Equivalent functions are
2408 not '==' only if one is a function-local extern function or if
2409 both are extern "C". */
2412 equal_functions (tree fn1, tree fn2)
2414 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2415 || DECL_EXTERN_C_FUNCTION_P (fn1))
2416 return decls_match (fn1, fn2);
2420 /* Print information about one overload candidate CANDIDATE. MSGSTR
2421 is the text to print before the candidate itself.
2423 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2424 to have been run through gettext by the caller. This wart makes
2425 life simpler in print_z_candidates and for the translators. */
2428 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2430 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2432 if (candidate->num_convs == 3)
2433 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2434 candidate->convs[0]->type,
2435 candidate->convs[1]->type,
2436 candidate->convs[2]->type);
2437 else if (candidate->num_convs == 2)
2438 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2439 candidate->convs[0]->type,
2440 candidate->convs[1]->type);
2442 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2443 candidate->convs[0]->type);
2445 else if (TYPE_P (candidate->fn))
2446 inform ("%s %T <conversion>", msgstr, candidate->fn);
2447 else if (candidate->viable == -1)
2448 inform ("%s %+#D <near match>", msgstr, candidate->fn);
2450 inform ("%s %+#D", msgstr, candidate->fn);
2454 print_z_candidates (struct z_candidate *candidates)
2457 struct z_candidate *cand1;
2458 struct z_candidate **cand2;
2460 /* There may be duplicates in the set of candidates. We put off
2461 checking this condition as long as possible, since we have no way
2462 to eliminate duplicates from a set of functions in less than n^2
2463 time. Now we are about to emit an error message, so it is more
2464 permissible to go slowly. */
2465 for (cand1 = candidates; cand1; cand1 = cand1->next)
2467 tree fn = cand1->fn;
2468 /* Skip builtin candidates and conversion functions. */
2469 if (TREE_CODE (fn) != FUNCTION_DECL)
2471 cand2 = &cand1->next;
2474 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2475 && equal_functions (fn, (*cand2)->fn))
2476 *cand2 = (*cand2)->next;
2478 cand2 = &(*cand2)->next;
2485 str = _("candidates are:");
2486 print_z_candidate (str, candidates);
2487 if (candidates->next)
2489 /* Indent successive candidates by the width of the translation
2490 of the above string. */
2491 size_t len = gcc_gettext_width (str) + 1;
2492 char *spaces = (char *) alloca (len);
2493 memset (spaces, ' ', len-1);
2494 spaces[len - 1] = '\0';
2496 candidates = candidates->next;
2499 print_z_candidate (spaces, candidates);
2500 candidates = candidates->next;
2506 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2507 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2508 the result of the conversion function to convert it to the final
2509 desired type. Merge the two sequences into a single sequence,
2510 and return the merged sequence. */
2513 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2517 gcc_assert (user_seq->kind == ck_user);
2519 /* Find the end of the second conversion sequence. */
2521 while ((*t)->kind != ck_identity)
2522 t = &((*t)->u.next);
2524 /* Replace the identity conversion with the user conversion
2528 /* The entire sequence is a user-conversion sequence. */
2529 std_seq->user_conv_p = true;
2534 /* Returns the best overload candidate to perform the requested
2535 conversion. This function is used for three the overloading situations
2536 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2537 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2538 per [dcl.init.ref], so we ignore temporary bindings. */
2540 static struct z_candidate *
2541 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2543 struct z_candidate *candidates, *cand;
2544 tree fromtype = TREE_TYPE (expr);
2545 tree ctors = NULL_TREE;
2546 tree conv_fns = NULL_TREE;
2547 conversion *conv = NULL;
2548 tree args = NULL_TREE;
2551 /* We represent conversion within a hierarchy using RVALUE_CONV and
2552 BASE_CONV, as specified by [over.best.ics]; these become plain
2553 constructor calls, as specified in [dcl.init]. */
2554 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2555 || !DERIVED_FROM_P (totype, fromtype));
2557 if (IS_AGGR_TYPE (totype))
2558 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2560 if (IS_AGGR_TYPE (fromtype))
2561 conv_fns = lookup_conversions (fromtype);
2564 flags |= LOOKUP_NO_CONVERSION;
2570 ctors = BASELINK_FUNCTIONS (ctors);
2572 t = build_int_cst (build_pointer_type (totype), 0);
2573 args = build_tree_list (NULL_TREE, expr);
2574 /* We should never try to call the abstract or base constructor
2576 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2577 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2578 args = tree_cons (NULL_TREE, t, args);
2580 for (; ctors; ctors = OVL_NEXT (ctors))
2582 tree ctor = OVL_CURRENT (ctors);
2583 if (DECL_NONCONVERTING_P (ctor))
2586 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2587 cand = add_template_candidate (&candidates, ctor, totype,
2588 NULL_TREE, args, NULL_TREE,
2589 TYPE_BINFO (totype),
2590 TYPE_BINFO (totype),
2594 cand = add_function_candidate (&candidates, ctor, totype,
2595 args, TYPE_BINFO (totype),
2596 TYPE_BINFO (totype),
2600 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2604 args = build_tree_list (NULL_TREE, build_this (expr));
2606 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2609 tree conversion_path = TREE_PURPOSE (conv_fns);
2610 int convflags = LOOKUP_NO_CONVERSION;
2612 /* If we are called to convert to a reference type, we are trying to
2613 find an lvalue binding, so don't even consider temporaries. If
2614 we don't find an lvalue binding, the caller will try again to
2615 look for a temporary binding. */
2616 if (TREE_CODE (totype) == REFERENCE_TYPE)
2617 convflags |= LOOKUP_NO_TEMP_BIND;
2619 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2621 tree fn = OVL_CURRENT (fns);
2623 /* [over.match.funcs] For conversion functions, the function
2624 is considered to be a member of the class of the implicit
2625 object argument for the purpose of defining the type of
2626 the implicit object parameter.
2628 So we pass fromtype as CTYPE to add_*_candidate. */
2630 if (TREE_CODE (fn) == TEMPLATE_DECL)
2631 cand = add_template_candidate (&candidates, fn, fromtype,
2634 TYPE_BINFO (fromtype),
2639 cand = add_function_candidate (&candidates, fn, fromtype,
2641 TYPE_BINFO (fromtype),
2648 = implicit_conversion (totype,
2649 TREE_TYPE (TREE_TYPE (cand->fn)),
2651 /*c_cast_p=*/false, convflags);
2653 cand->second_conv = ics;
2657 else if (candidates->viable == 1 && ics->bad_p)
2663 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2667 cand = tourney (candidates);
2670 if (flags & LOOKUP_COMPLAIN)
2672 error ("conversion from %qT to %qT is ambiguous",
2674 print_z_candidates (candidates);
2677 cand = candidates; /* any one will do */
2678 cand->second_conv = build_ambiguous_conv (totype, expr);
2679 cand->second_conv->user_conv_p = true;
2680 if (!any_strictly_viable (candidates))
2681 cand->second_conv->bad_p = true;
2682 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2683 ambiguous conversion is no worse than another user-defined
2689 /* Build the user conversion sequence. */
2692 (DECL_CONSTRUCTOR_P (cand->fn)
2693 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2694 build_identity_conv (TREE_TYPE (expr), expr));
2697 /* Combine it with the second conversion sequence. */
2698 cand->second_conv = merge_conversion_sequences (conv,
2701 if (cand->viable == -1)
2702 cand->second_conv->bad_p = true;
2708 build_user_type_conversion (tree totype, tree expr, int flags)
2710 struct z_candidate *cand
2711 = build_user_type_conversion_1 (totype, expr, flags);
2715 if (cand->second_conv->kind == ck_ambig)
2716 return error_mark_node;
2717 expr = convert_like (cand->second_conv, expr);
2718 return convert_from_reference (expr);
2723 /* Do any initial processing on the arguments to a function call. */
2726 resolve_args (tree args)
2729 for (t = args; t; t = TREE_CHAIN (t))
2731 tree arg = TREE_VALUE (t);
2733 if (error_operand_p (arg))
2734 return error_mark_node;
2735 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2737 error ("invalid use of void expression");
2738 return error_mark_node;
2740 else if (invalid_nonstatic_memfn_p (arg))
2741 return error_mark_node;
2746 /* Perform overload resolution on FN, which is called with the ARGS.
2748 Return the candidate function selected by overload resolution, or
2749 NULL if the event that overload resolution failed. In the case
2750 that overload resolution fails, *CANDIDATES will be the set of
2751 candidates considered, and ANY_VIABLE_P will be set to true or
2752 false to indicate whether or not any of the candidates were
2755 The ARGS should already have gone through RESOLVE_ARGS before this
2756 function is called. */
2758 static struct z_candidate *
2759 perform_overload_resolution (tree fn,
2761 struct z_candidate **candidates,
2764 struct z_candidate *cand;
2765 tree explicit_targs = NULL_TREE;
2766 int template_only = 0;
2769 *any_viable_p = true;
2771 /* Check FN and ARGS. */
2772 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2773 || TREE_CODE (fn) == TEMPLATE_DECL
2774 || TREE_CODE (fn) == OVERLOAD
2775 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2776 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2778 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2780 explicit_targs = TREE_OPERAND (fn, 1);
2781 fn = TREE_OPERAND (fn, 0);
2785 /* Add the various candidate functions. */
2786 add_candidates (fn, args, explicit_targs, template_only,
2787 /*conversion_path=*/NULL_TREE,
2788 /*access_path=*/NULL_TREE,
2792 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2796 cand = tourney (*candidates);
2800 /* Return an expression for a call to FN (a namespace-scope function,
2801 or a static member function) with the ARGS. */
2804 build_new_function_call (tree fn, tree args, bool koenig_p)
2806 struct z_candidate *candidates, *cand;
2811 args = resolve_args (args);
2812 if (args == error_mark_node)
2813 return error_mark_node;
2815 /* If this function was found without using argument dependent
2816 lookup, then we want to ignore any undeclared friend
2822 fn = remove_hidden_names (fn);
2825 error ("no matching function for call to %<%D(%A)%>",
2826 DECL_NAME (OVL_CURRENT (orig_fn)), args);
2827 return error_mark_node;
2831 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2832 p = conversion_obstack_alloc (0);
2834 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2838 if (!any_viable_p && candidates && ! candidates->next)
2839 return build_function_call (candidates->fn, args);
2840 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2841 fn = TREE_OPERAND (fn, 0);
2843 error ("no matching function for call to %<%D(%A)%>",
2844 DECL_NAME (OVL_CURRENT (fn)), args);
2846 error ("call of overloaded %<%D(%A)%> is ambiguous",
2847 DECL_NAME (OVL_CURRENT (fn)), args);
2849 print_z_candidates (candidates);
2850 result = error_mark_node;
2853 result = build_over_call (cand, LOOKUP_NORMAL);
2855 /* Free all the conversions we allocated. */
2856 obstack_free (&conversion_obstack, p);
2861 /* Build a call to a global operator new. FNNAME is the name of the
2862 operator (either "operator new" or "operator new[]") and ARGS are
2863 the arguments provided. *SIZE points to the total number of bytes
2864 required by the allocation, and is updated if that is changed here.
2865 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2866 function determines that no cookie should be used, after all,
2867 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2868 set, upon return, to the allocation function called. */
2871 build_operator_new_call (tree fnname, tree args,
2872 tree *size, tree *cookie_size,
2876 struct z_candidate *candidates;
2877 struct z_candidate *cand;
2882 args = tree_cons (NULL_TREE, *size, args);
2883 args = resolve_args (args);
2884 if (args == error_mark_node)
2891 If this lookup fails to find the name, or if the allocated type
2892 is not a class type, the allocation function's name is looked
2893 up in the global scope.
2895 we disregard block-scope declarations of "operator new". */
2896 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2898 /* Figure out what function is being called. */
2899 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2901 /* If no suitable function could be found, issue an error message
2906 error ("no matching function for call to %<%D(%A)%>",
2907 DECL_NAME (OVL_CURRENT (fns)), args);
2909 error ("call of overloaded %<%D(%A)%> is ambiguous",
2910 DECL_NAME (OVL_CURRENT (fns)), args);
2912 print_z_candidates (candidates);
2913 return error_mark_node;
2916 /* If a cookie is required, add some extra space. Whether
2917 or not a cookie is required cannot be determined until
2918 after we know which function was called. */
2921 bool use_cookie = true;
2922 if (!abi_version_at_least (2))
2924 tree placement = TREE_CHAIN (args);
2925 /* In G++ 3.2, the check was implemented incorrectly; it
2926 looked at the placement expression, rather than the
2927 type of the function. */
2928 if (placement && !TREE_CHAIN (placement)
2929 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2937 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2938 /* Skip the size_t parameter. */
2939 arg_types = TREE_CHAIN (arg_types);
2940 /* Check the remaining parameters (if any). */
2942 && TREE_CHAIN (arg_types) == void_list_node
2943 && same_type_p (TREE_VALUE (arg_types),
2947 /* If we need a cookie, adjust the number of bytes allocated. */
2950 /* Update the total size. */
2951 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2952 /* Update the argument list to reflect the adjusted size. */
2953 TREE_VALUE (args) = *size;
2956 *cookie_size = NULL_TREE;
2959 /* Tell our caller which function we decided to call. */
2963 /* Build the CALL_EXPR. */
2964 return build_over_call (cand, LOOKUP_NORMAL);
2968 build_object_call (tree obj, tree args)
2970 struct z_candidate *candidates = 0, *cand;
2971 tree fns, convs, mem_args = NULL_TREE;
2972 tree type = TREE_TYPE (obj);
2974 tree result = NULL_TREE;
2977 if (TYPE_PTRMEMFUNC_P (type))
2979 /* It's no good looking for an overloaded operator() on a
2980 pointer-to-member-function. */
2981 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
2982 return error_mark_node;
2985 if (TYPE_BINFO (type))
2987 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
2988 if (fns == error_mark_node)
2989 return error_mark_node;
2994 args = resolve_args (args);
2996 if (args == error_mark_node)
2997 return error_mark_node;
2999 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3000 p = conversion_obstack_alloc (0);
3004 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
3005 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
3007 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3009 tree fn = OVL_CURRENT (fns);
3010 if (TREE_CODE (fn) == TEMPLATE_DECL)
3011 add_template_candidate (&candidates, fn, base, NULL_TREE,
3012 mem_args, NULL_TREE,
3015 LOOKUP_NORMAL, DEDUCE_CALL);
3017 add_function_candidate
3018 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3019 TYPE_BINFO (type), LOOKUP_NORMAL);
3023 convs = lookup_conversions (type);
3025 for (; convs; convs = TREE_CHAIN (convs))
3027 tree fns = TREE_VALUE (convs);
3028 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3030 if ((TREE_CODE (totype) == POINTER_TYPE
3031 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3032 || (TREE_CODE (totype) == REFERENCE_TYPE
3033 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3034 || (TREE_CODE (totype) == REFERENCE_TYPE
3035 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3036 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3037 for (; fns; fns = OVL_NEXT (fns))
3039 tree fn = OVL_CURRENT (fns);
3040 if (TREE_CODE (fn) == TEMPLATE_DECL)
3041 add_template_conv_candidate
3042 (&candidates, fn, obj, args, totype,
3043 /*access_path=*/NULL_TREE,
3044 /*conversion_path=*/NULL_TREE);
3046 add_conv_candidate (&candidates, fn, obj, args,
3047 /*conversion_path=*/NULL_TREE,
3048 /*access_path=*/NULL_TREE);
3052 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3055 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3056 print_z_candidates (candidates);
3057 result = error_mark_node;
3061 cand = tourney (candidates);
3064 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
3065 print_z_candidates (candidates);
3066 result = error_mark_node;
3068 /* Since cand->fn will be a type, not a function, for a conversion
3069 function, we must be careful not to unconditionally look at
3071 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3072 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3073 result = build_over_call (cand, LOOKUP_NORMAL);
3076 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
3077 obj = convert_from_reference (obj);
3078 result = build_function_call (obj, args);
3082 /* Free all the conversions we allocated. */
3083 obstack_free (&conversion_obstack, p);
3089 op_error (enum tree_code code, enum tree_code code2,
3090 tree arg1, tree arg2, tree arg3, const char *problem)
3094 if (code == MODIFY_EXPR)
3095 opname = assignment_operator_name_info[code2].name;
3097 opname = operator_name_info[code].name;
3102 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3103 problem, arg1, arg2, arg3);
3106 case POSTINCREMENT_EXPR:
3107 case POSTDECREMENT_EXPR:
3108 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3112 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3117 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3122 error ("%s for %<operator%s%> in %<%E %s %E%>",
3123 problem, opname, arg1, opname, arg2);
3125 error ("%s for %<operator%s%> in %<%s%E%>",
3126 problem, opname, opname, arg1);
3131 /* Return the implicit conversion sequence that could be used to
3132 convert E1 to E2 in [expr.cond]. */
3135 conditional_conversion (tree e1, tree e2)
3137 tree t1 = non_reference (TREE_TYPE (e1));
3138 tree t2 = non_reference (TREE_TYPE (e2));
3144 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3145 implicitly converted (clause _conv_) to the type "reference to
3146 T2", subject to the constraint that in the conversion the
3147 reference must bind directly (_dcl.init.ref_) to E1. */
3148 if (real_lvalue_p (e2))
3150 conv = implicit_conversion (build_reference_type (t2),
3154 LOOKUP_NO_TEMP_BIND);
3161 If E1 and E2 have class type, and the underlying class types are
3162 the same or one is a base class of the other: E1 can be converted
3163 to match E2 if the class of T2 is the same type as, or a base
3164 class of, the class of T1, and the cv-qualification of T2 is the
3165 same cv-qualification as, or a greater cv-qualification than, the
3166 cv-qualification of T1. If the conversion is applied, E1 is
3167 changed to an rvalue of type T2 that still refers to the original
3168 source class object (or the appropriate subobject thereof). */
3169 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3170 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3172 if (good_base && at_least_as_qualified_p (t2, t1))
3174 conv = build_identity_conv (t1, e1);
3175 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3176 TYPE_MAIN_VARIANT (t2)))
3177 conv = build_conv (ck_base, t2, conv);
3179 conv = build_conv (ck_rvalue, t2, conv);
3188 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3189 converted to the type that expression E2 would have if E2 were
3190 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3191 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3195 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3196 arguments to the conditional expression. */
3199 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3203 tree result = NULL_TREE;
3204 tree result_type = NULL_TREE;
3205 bool lvalue_p = true;
3206 struct z_candidate *candidates = 0;
3207 struct z_candidate *cand;
3210 /* As a G++ extension, the second argument to the conditional can be
3211 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3212 c'.) If the second operand is omitted, make sure it is
3213 calculated only once. */
3217 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3219 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3220 if (real_lvalue_p (arg1))
3221 arg2 = arg1 = stabilize_reference (arg1);
3223 arg2 = arg1 = save_expr (arg1);
3228 The first expr ession is implicitly converted to bool (clause
3230 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3232 /* If something has already gone wrong, just pass that fact up the
3234 if (error_operand_p (arg1)
3235 || error_operand_p (arg2)
3236 || error_operand_p (arg3))
3237 return error_mark_node;
3241 If either the second or the third operand has type (possibly
3242 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3243 array-to-pointer (_conv.array_), and function-to-pointer
3244 (_conv.func_) standard conversions are performed on the second
3245 and third operands. */
3246 arg2_type = unlowered_expr_type (arg2);
3247 arg3_type = unlowered_expr_type (arg3);
3248 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3250 /* Do the conversions. We don't these for `void' type arguments
3251 since it can't have any effect and since decay_conversion
3252 does not handle that case gracefully. */
3253 if (!VOID_TYPE_P (arg2_type))
3254 arg2 = decay_conversion (arg2);
3255 if (!VOID_TYPE_P (arg3_type))
3256 arg3 = decay_conversion (arg3);
3257 arg2_type = TREE_TYPE (arg2);
3258 arg3_type = TREE_TYPE (arg3);
3262 One of the following shall hold:
3264 --The second or the third operand (but not both) is a
3265 throw-expression (_except.throw_); the result is of the
3266 type of the other and is an rvalue.
3268 --Both the second and the third operands have type void; the
3269 result is of type void and is an rvalue.
3271 We must avoid calling force_rvalue for expressions of type
3272 "void" because it will complain that their value is being
3274 if (TREE_CODE (arg2) == THROW_EXPR
3275 && TREE_CODE (arg3) != THROW_EXPR)
3277 if (!VOID_TYPE_P (arg3_type))
3278 arg3 = force_rvalue (arg3);
3279 arg3_type = TREE_TYPE (arg3);
3280 result_type = arg3_type;
3282 else if (TREE_CODE (arg2) != THROW_EXPR
3283 && TREE_CODE (arg3) == THROW_EXPR)
3285 if (!VOID_TYPE_P (arg2_type))
3286 arg2 = force_rvalue (arg2);
3287 arg2_type = TREE_TYPE (arg2);
3288 result_type = arg2_type;
3290 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3291 result_type = void_type_node;
3294 error ("%qE has type %<void%> and is not a throw-expression",
3295 VOID_TYPE_P (arg2_type) ? arg2 : arg3);
3296 return error_mark_node;
3300 goto valid_operands;
3304 Otherwise, if the second and third operand have different types,
3305 and either has (possibly cv-qualified) class type, an attempt is
3306 made to convert each of those operands to the type of the other. */
3307 else if (!same_type_p (arg2_type, arg3_type)
3308 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3313 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3314 p = conversion_obstack_alloc (0);
3316 conv2 = conditional_conversion (arg2, arg3);
3317 conv3 = conditional_conversion (arg3, arg2);
3321 If both can be converted, or one can be converted but the
3322 conversion is ambiguous, the program is ill-formed. If
3323 neither can be converted, the operands are left unchanged and
3324 further checking is performed as described below. If exactly
3325 one conversion is possible, that conversion is applied to the
3326 chosen operand and the converted operand is used in place of
3327 the original operand for the remainder of this section. */
3328 if ((conv2 && !conv2->bad_p
3329 && conv3 && !conv3->bad_p)
3330 || (conv2 && conv2->kind == ck_ambig)
3331 || (conv3 && conv3->kind == ck_ambig))
3333 error ("operands to ?: have different types %qT and %qT",
3334 arg2_type, arg3_type);
3335 result = error_mark_node;
3337 else if (conv2 && (!conv2->bad_p || !conv3))
3339 arg2 = convert_like (conv2, arg2);
3340 arg2 = convert_from_reference (arg2);
3341 arg2_type = TREE_TYPE (arg2);
3342 /* Even if CONV2 is a valid conversion, the result of the
3343 conversion may be invalid. For example, if ARG3 has type
3344 "volatile X", and X does not have a copy constructor
3345 accepting a "volatile X&", then even if ARG2 can be
3346 converted to X, the conversion will fail. */
3347 if (error_operand_p (arg2))
3348 result = error_mark_node;
3350 else if (conv3 && (!conv3->bad_p || !conv2))
3352 arg3 = convert_like (conv3, arg3);
3353 arg3 = convert_from_reference (arg3);
3354 arg3_type = TREE_TYPE (arg3);
3355 if (error_operand_p (arg3))
3356 result = error_mark_node;
3359 /* Free all the conversions we allocated. */
3360 obstack_free (&conversion_obstack, p);
3365 /* If, after the conversion, both operands have class type,
3366 treat the cv-qualification of both operands as if it were the
3367 union of the cv-qualification of the operands.
3369 The standard is not clear about what to do in this
3370 circumstance. For example, if the first operand has type
3371 "const X" and the second operand has a user-defined
3372 conversion to "volatile X", what is the type of the second
3373 operand after this step? Making it be "const X" (matching
3374 the first operand) seems wrong, as that discards the
3375 qualification without actually performing a copy. Leaving it
3376 as "volatile X" seems wrong as that will result in the
3377 conditional expression failing altogether, even though,
3378 according to this step, the one operand could be converted to
3379 the type of the other. */
3380 if ((conv2 || conv3)
3381 && CLASS_TYPE_P (arg2_type)
3382 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3383 arg2_type = arg3_type =
3384 cp_build_qualified_type (arg2_type,
3385 TYPE_QUALS (arg2_type)
3386 | TYPE_QUALS (arg3_type));
3391 If the second and third operands are lvalues and have the same
3392 type, the result is of that type and is an lvalue. */
3393 if (real_lvalue_p (arg2)
3394 && real_lvalue_p (arg3)
3395 && same_type_p (arg2_type, arg3_type))
3397 result_type = arg2_type;
3398 goto valid_operands;
3403 Otherwise, the result is an rvalue. If the second and third
3404 operand do not have the same type, and either has (possibly
3405 cv-qualified) class type, overload resolution is used to
3406 determine the conversions (if any) to be applied to the operands
3407 (_over.match.oper_, _over.built_). */
3409 if (!same_type_p (arg2_type, arg3_type)
3410 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3416 /* Rearrange the arguments so that add_builtin_candidate only has
3417 to know about two args. In build_builtin_candidates, the
3418 arguments are unscrambled. */
3422 add_builtin_candidates (&candidates,
3425 ansi_opname (COND_EXPR),
3431 If the overload resolution fails, the program is
3433 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3436 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3437 print_z_candidates (candidates);
3438 return error_mark_node;
3440 cand = tourney (candidates);
3443 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3444 print_z_candidates (candidates);
3445 return error_mark_node;
3450 Otherwise, the conversions thus determined are applied, and
3451 the converted operands are used in place of the original
3452 operands for the remainder of this section. */
3453 conv = cand->convs[0];
3454 arg1 = convert_like (conv, arg1);
3455 conv = cand->convs[1];
3456 arg2 = convert_like (conv, arg2);
3457 conv = cand->convs[2];
3458 arg3 = convert_like (conv, arg3);
3463 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3464 and function-to-pointer (_conv.func_) standard conversions are
3465 performed on the second and third operands.
3467 We need to force the lvalue-to-rvalue conversion here for class types,
3468 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3469 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3472 arg2 = force_rvalue (arg2);
3473 if (!CLASS_TYPE_P (arg2_type))
3474 arg2_type = TREE_TYPE (arg2);
3476 arg3 = force_rvalue (arg3);
3477 if (!CLASS_TYPE_P (arg2_type))
3478 arg3_type = TREE_TYPE (arg3);
3480 if (arg2 == error_mark_node || arg3 == error_mark_node)
3481 return error_mark_node;
3485 After those conversions, one of the following shall hold:
3487 --The second and third operands have the same type; the result is of
3489 if (same_type_p (arg2_type, arg3_type))
3490 result_type = arg2_type;
3493 --The second and third operands have arithmetic or enumeration
3494 type; the usual arithmetic conversions are performed to bring
3495 them to a common type, and the result is of that type. */
3496 else if ((ARITHMETIC_TYPE_P (arg2_type)
3497 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3498 && (ARITHMETIC_TYPE_P (arg3_type)
3499 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3501 /* In this case, there is always a common type. */
3502 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3505 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3506 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3507 warning (0, "enumeral mismatch in conditional expression: %qT vs %qT",
3508 arg2_type, arg3_type);
3509 else if (extra_warnings
3510 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3511 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3512 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3513 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3514 warning (0, "enumeral and non-enumeral type in conditional expression");
3516 arg2 = perform_implicit_conversion (result_type, arg2);
3517 arg3 = perform_implicit_conversion (result_type, arg3);
3521 --The second and third operands have pointer type, or one has
3522 pointer type and the other is a null pointer constant; pointer
3523 conversions (_conv.ptr_) and qualification conversions
3524 (_conv.qual_) are performed to bring them to their composite
3525 pointer type (_expr.rel_). The result is of the composite
3528 --The second and third operands have pointer to member type, or
3529 one has pointer to member type and the other is a null pointer
3530 constant; pointer to member conversions (_conv.mem_) and
3531 qualification conversions (_conv.qual_) are performed to bring
3532 them to a common type, whose cv-qualification shall match the
3533 cv-qualification of either the second or the third operand.
3534 The result is of the common type. */
3535 else if ((null_ptr_cst_p (arg2)
3536 /* APPLE LOCAL begin blocks 6040305 (co) */
3537 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)
3538 || TREE_CODE (arg3_type) == BLOCK_POINTER_TYPE))
3539 /* APPLE LOCAL end blocks 6040305 (co) */
3540 || (null_ptr_cst_p (arg3)
3541 /* APPLE LOCAL begin blocks 6040305 (co) */
3542 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)
3543 || TREE_CODE (arg2_type) == BLOCK_POINTER_TYPE))
3544 || ((TYPE_PTR_P (arg2_type)
3545 || TREE_CODE (arg2_type) == BLOCK_POINTER_TYPE)
3546 && (TYPE_PTR_P (arg3_type)
3547 || TREE_CODE (arg3_type) == BLOCK_POINTER_TYPE))
3548 /* APPLE LOCAL end blocks 6040305 (co) */
3549 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3550 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3552 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3553 arg3, "conditional expression");
3554 if (result_type == error_mark_node)
3555 return error_mark_node;
3556 arg2 = perform_implicit_conversion (result_type, arg2);
3557 arg3 = perform_implicit_conversion (result_type, arg3);
3562 error ("operands to ?: have different types %qT and %qT",
3563 arg2_type, arg3_type);
3564 return error_mark_node;
3568 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3570 /* We can't use result_type below, as fold might have returned a
3575 /* Expand both sides into the same slot, hopefully the target of
3576 the ?: expression. We used to check for TARGET_EXPRs here,
3577 but now we sometimes wrap them in NOP_EXPRs so the test would
3579 if (CLASS_TYPE_P (TREE_TYPE (result)))
3580 result = get_target_expr (result);
3581 /* If this expression is an rvalue, but might be mistaken for an
3582 lvalue, we must add a NON_LVALUE_EXPR. */
3583 result = rvalue (result);
3589 /* OPERAND is an operand to an expression. Perform necessary steps
3590 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3594 prep_operand (tree operand)
3598 if (CLASS_TYPE_P (TREE_TYPE (operand))
3599 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3600 /* Make sure the template type is instantiated now. */
3601 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3607 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3608 OVERLOAD) to the CANDIDATES, returning an updated list of
3609 CANDIDATES. The ARGS are the arguments provided to the call,
3610 without any implicit object parameter. The EXPLICIT_TARGS are
3611 explicit template arguments provided. TEMPLATE_ONLY is true if
3612 only template functions should be considered. CONVERSION_PATH,
3613 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3616 add_candidates (tree fns, tree args,
3617 tree explicit_targs, bool template_only,
3618 tree conversion_path, tree access_path,
3620 struct z_candidate **candidates)
3623 tree non_static_args;
3625 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3626 /* Delay creating the implicit this parameter until it is needed. */
3627 non_static_args = NULL_TREE;
3634 fn = OVL_CURRENT (fns);
3635 /* Figure out which set of arguments to use. */
3636 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3638 /* If this function is a non-static member, prepend the implicit
3639 object parameter. */
3640 if (!non_static_args)
3641 non_static_args = tree_cons (NULL_TREE,
3642 build_this (TREE_VALUE (args)),
3644 fn_args = non_static_args;
3647 /* Otherwise, just use the list of arguments provided. */
3650 if (TREE_CODE (fn) == TEMPLATE_DECL)
3651 add_template_candidate (candidates,
3661 else if (!template_only)
3662 add_function_candidate (candidates,
3669 fns = OVL_NEXT (fns);
3674 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3677 struct z_candidate *candidates = 0, *cand;
3678 tree arglist, fnname;
3680 tree result = NULL_TREE;
3681 bool result_valid_p = false;
3682 enum tree_code code2 = NOP_EXPR;
3688 if (error_operand_p (arg1)
3689 || error_operand_p (arg2)
3690 || error_operand_p (arg3))
3691 return error_mark_node;
3693 if (code == MODIFY_EXPR)
3695 code2 = TREE_CODE (arg3);
3697 fnname = ansi_assopname (code2);
3700 fnname = ansi_opname (code);
3702 arg1 = prep_operand (arg1);
3708 case VEC_DELETE_EXPR:
3710 /* Use build_op_new_call and build_op_delete_call instead. */
3714 return build_object_call (arg1, arg2);
3720 arg2 = prep_operand (arg2);
3721 arg3 = prep_operand (arg3);
3723 if (code == COND_EXPR)
3725 if (arg2 == NULL_TREE
3726 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3727 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3728 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3729 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3732 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3733 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3736 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3737 arg2 = integer_zero_node;
3739 arglist = NULL_TREE;
3741 arglist = tree_cons (NULL_TREE, arg3, arglist);
3743 arglist = tree_cons (NULL_TREE, arg2, arglist);
3744 arglist = tree_cons (NULL_TREE, arg1, arglist);
3746 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3747 p = conversion_obstack_alloc (0);
3749 /* Add namespace-scope operators to the list of functions to
3751 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3752 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3753 flags, &candidates);
3754 /* Add class-member operators to the candidate set. */
3755 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3759 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3760 if (fns == error_mark_node)
3762 result = error_mark_node;
3763 goto user_defined_result_ready;
3766 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3768 BASELINK_BINFO (fns),
3769 TYPE_BINFO (TREE_TYPE (arg1)),
3770 flags, &candidates);
3773 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3774 to know about two args; a builtin candidate will always have a first
3775 parameter of type bool. We'll handle that in
3776 build_builtin_candidate. */
3777 if (code == COND_EXPR)
3787 args[2] = NULL_TREE;
3790 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3796 /* For these, the built-in candidates set is empty
3797 [over.match.oper]/3. We don't want non-strict matches
3798 because exact matches are always possible with built-in
3799 operators. The built-in candidate set for COMPONENT_REF
3800 would be empty too, but since there are no such built-in
3801 operators, we accept non-strict matches for them. */
3806 strict_p = pedantic;
3810 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3815 case POSTINCREMENT_EXPR:
3816 case POSTDECREMENT_EXPR:
3817 /* Look for an `operator++ (int)'. If they didn't have
3818 one, then we fall back to the old way of doing things. */
3819 if (flags & LOOKUP_COMPLAIN)
3820 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3821 "trying prefix operator instead",
3823 operator_name_info[code].name);
3824 if (code == POSTINCREMENT_EXPR)
3825 code = PREINCREMENT_EXPR;
3827 code = PREDECREMENT_EXPR;
3828 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3832 /* The caller will deal with these. */
3837 result_valid_p = true;
3841 if (flags & LOOKUP_COMPLAIN)
3843 op_error (code, code2, arg1, arg2, arg3, "no match");
3844 print_z_candidates (candidates);
3846 result = error_mark_node;
3852 cand = tourney (candidates);
3855 if (flags & LOOKUP_COMPLAIN)
3857 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3858 print_z_candidates (candidates);
3860 result = error_mark_node;
3862 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3865 *overloaded_p = true;
3867 result = build_over_call (cand, LOOKUP_NORMAL);
3871 /* Give any warnings we noticed during overload resolution. */
3874 struct candidate_warning *w;
3875 for (w = cand->warnings; w; w = w->next)
3876 joust (cand, w->loser, 1);
3879 /* Check for comparison of different enum types. */
3888 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3889 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3890 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3891 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3893 warning (0, "comparison between %q#T and %q#T",
3894 TREE_TYPE (arg1), TREE_TYPE (arg2));
3901 /* We need to strip any leading REF_BIND so that bitfields
3902 don't cause errors. This should not remove any important
3903 conversions, because builtins don't apply to class
3904 objects directly. */
3905 conv = cand->convs[0];
3906 if (conv->kind == ck_ref_bind)
3907 conv = conv->u.next;
3908 arg1 = convert_like (conv, arg1);
3911 conv = cand->convs[1];
3912 if (conv->kind == ck_ref_bind)
3913 conv = conv->u.next;
3914 arg2 = convert_like (conv, arg2);
3918 conv = cand->convs[2];
3919 if (conv->kind == ck_ref_bind)
3920 conv = conv->u.next;
3921 arg3 = convert_like (conv, arg3);
3926 user_defined_result_ready:
3928 /* Free all the conversions we allocated. */
3929 obstack_free (&conversion_obstack, p);
3931 if (result || result_valid_p)
3938 return build_modify_expr (arg1, code2, arg2);
3941 return build_indirect_ref (arg1, "unary *");
3946 case TRUNC_DIV_EXPR:
3957 case TRUNC_MOD_EXPR:
3961 case TRUTH_ANDIF_EXPR:
3962 case TRUTH_ORIF_EXPR:
3963 return cp_build_binary_op (code, arg1, arg2);
3965 case UNARY_PLUS_EXPR:
3968 case TRUTH_NOT_EXPR:
3969 case PREINCREMENT_EXPR:
3970 case POSTINCREMENT_EXPR:
3971 case PREDECREMENT_EXPR:
3972 case POSTDECREMENT_EXPR:
3975 return build_unary_op (code, arg1, candidates != 0);
3978 return build_array_ref (arg1, arg2);
3981 return build_conditional_expr (arg1, arg2, arg3);
3984 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
3986 /* The caller will deal with these. */
3998 /* Build a call to operator delete. This has to be handled very specially,
3999 because the restrictions on what signatures match are different from all
4000 other call instances. For a normal delete, only a delete taking (void *)
4001 or (void *, size_t) is accepted. For a placement delete, only an exact
4002 match with the placement new is accepted.
4004 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4005 ADDR is the pointer to be deleted.
4006 SIZE is the size of the memory block to be deleted.
4007 GLOBAL_P is true if the delete-expression should not consider
4008 class-specific delete operators.
4009 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4011 If this call to "operator delete" is being generated as part to
4012 deallocate memory allocated via a new-expression (as per [expr.new]
4013 which requires that if the initialization throws an exception then
4014 we call a deallocation function), then ALLOC_FN is the allocation
4018 build_op_delete_call (enum tree_code code, tree addr, tree size,
4019 bool global_p, tree placement,
4022 tree fn = NULL_TREE;
4023 tree fns, fnname, argtypes, args, type;
4026 if (addr == error_mark_node)
4027 return error_mark_node;
4029 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4031 fnname = ansi_opname (code);
4033 if (CLASS_TYPE_P (type)
4034 && COMPLETE_TYPE_P (complete_type (type))
4038 If the result of the lookup is ambiguous or inaccessible, or if
4039 the lookup selects a placement deallocation function, the
4040 program is ill-formed.
4042 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4044 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4045 if (fns == error_mark_node)
4046 return error_mark_node;
4051 if (fns == NULL_TREE)
4052 fns = lookup_name_nonclass (fnname);
4056 /* Get the parameter types for the allocation function that is
4058 gcc_assert (alloc_fn != NULL_TREE);
4059 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4060 /* Also the second argument. */
4061 args = TREE_CHAIN (TREE_OPERAND (placement, 1));
4065 /* First try it without the size argument. */
4066 argtypes = void_list_node;
4070 /* Strip const and volatile from addr. */
4071 addr = cp_convert (ptr_type_node, addr);
4073 /* We make two tries at finding a matching `operator delete'. On
4074 the first pass, we look for a one-operator (or placement)
4075 operator delete. If we're not doing placement delete, then on
4076 the second pass we look for a two-argument delete. */
4077 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4079 /* Go through the `operator delete' functions looking for one
4080 with a matching type. */
4081 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4087 /* The first argument must be "void *". */
4088 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4089 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4092 /* On the first pass, check the rest of the arguments. */
4098 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4106 /* On the second pass, look for a function with exactly two
4107 arguments: "void *" and "size_t". */
4109 /* For "operator delete(void *, ...)" there will be
4110 no second argument, but we will not get an exact
4113 && same_type_p (TREE_VALUE (t), sizetype)
4114 && TREE_CHAIN (t) == void_list_node)
4118 /* If we found a match, we're done. */
4123 /* If we have a matching function, call it. */
4126 /* Make sure we have the actual function, and not an
4128 fn = OVL_CURRENT (fn);
4130 /* If the FN is a member function, make sure that it is
4132 if (DECL_CLASS_SCOPE_P (fn))
4133 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4136 args = tree_cons (NULL_TREE, addr, args);
4138 args = tree_cons (NULL_TREE, addr,
4139 build_tree_list (NULL_TREE, size));
4143 /* The placement args might not be suitable for overload
4144 resolution at this point, so build the call directly. */
4146 return build_cxx_call (fn, args);
4149 return build_function_call (fn, args);
4154 If no unambiguous matching deallocation function can be found,
4155 propagating the exception does not cause the object's memory to
4160 warning (0, "no corresponding deallocation function for `%D'",
4165 error ("no suitable %<operator %s%> for %qT",
4166 operator_name_info[(int)code].name, type);
4167 return error_mark_node;
4170 /* If the current scope isn't allowed to access DECL along
4171 BASETYPE_PATH, give an error. The most derived class in
4172 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4173 the declaration to use in the error diagnostic. */
4176 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4178 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4180 if (!accessible_p (basetype_path, decl, true))
4182 if (TREE_PRIVATE (decl))
4183 error ("%q+#D is private", diag_decl);
4184 else if (TREE_PROTECTED (decl))
4185 error ("%q+#D is protected", diag_decl);
4187 error ("%q+#D is inaccessible", diag_decl);
4188 error ("within this context");
4195 /* Check that a callable constructor to initialize a temporary of
4196 TYPE from an EXPR exists. */
4199 check_constructor_callable (tree type, tree expr)
4201 build_special_member_call (NULL_TREE,
4202 complete_ctor_identifier,
4203 build_tree_list (NULL_TREE, expr),
4205 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4206 | LOOKUP_NO_CONVERSION
4207 | LOOKUP_CONSTRUCTOR_CALLABLE);
4210 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4211 bitwise or of LOOKUP_* values. If any errors are warnings are
4212 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4213 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4217 build_temp (tree expr, tree type, int flags,
4218 diagnostic_fn_t *diagnostic_fn)
4222 savew = warningcount, savee = errorcount;
4223 expr = build_special_member_call (NULL_TREE,
4224 complete_ctor_identifier,
4225 build_tree_list (NULL_TREE, expr),
4227 if (warningcount > savew)
4228 *diagnostic_fn = warning0;
4229 else if (errorcount > savee)
4230 *diagnostic_fn = error;
4232 *diagnostic_fn = NULL;
4237 /* Perform the conversions in CONVS on the expression EXPR. FN and
4238 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4239 indicates the `this' argument of a method. INNER is nonzero when
4240 being called to continue a conversion chain. It is negative when a
4241 reference binding will be applied, positive otherwise. If
4242 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4243 conversions will be emitted if appropriate. If C_CAST_P is true,
4244 this conversion is coming from a C-style cast; in that case,
4245 conversions to inaccessible bases are permitted. */
4248 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4249 int inner, bool issue_conversion_warnings,
4252 tree totype = convs->type;
4253 diagnostic_fn_t diagnostic_fn;
4256 && convs->kind != ck_user
4257 && convs->kind != ck_ambig
4258 && convs->kind != ck_ref_bind)
4260 conversion *t = convs;
4261 for (; t; t = convs->u.next)
4263 if (t->kind == ck_user || !t->bad_p)
4265 expr = convert_like_real (t, expr, fn, argnum, 1,
4266 /*issue_conversion_warnings=*/false,
4267 /*c_cast_p=*/false);
4270 else if (t->kind == ck_ambig)
4271 return convert_like_real (t, expr, fn, argnum, 1,
4272 /*issue_conversion_warnings=*/false,
4273 /*c_cast_p=*/false);
4274 else if (t->kind == ck_identity)
4277 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4279 pedwarn (" initializing argument %P of %qD", argnum, fn);
4280 return cp_convert (totype, expr);
4283 if (issue_conversion_warnings)
4285 tree t = non_reference (totype);
4287 /* Issue warnings about peculiar, but valid, uses of NULL. */
4288 if (ARITHMETIC_TYPE_P (t) && expr == null_node)
4291 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4294 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4297 /* Warn about assigning a floating-point type to an integer type. */
4298 if (TREE_CODE (TREE_TYPE (expr)) == REAL_TYPE
4299 && TREE_CODE (t) == INTEGER_TYPE)
4302 warning (OPT_Wconversion, "passing %qT for argument %P to %qD",
4303 TREE_TYPE (expr), argnum, fn);
4305 warning (OPT_Wconversion, "converting to %qT from %qT", t, TREE_TYPE (expr));
4309 switch (convs->kind)
4313 struct z_candidate *cand = convs->cand;
4314 tree convfn = cand->fn;
4317 if (DECL_CONSTRUCTOR_P (convfn))
4319 tree t = build_int_cst (build_pointer_type (DECL_CONTEXT (convfn)),
4322 args = build_tree_list (NULL_TREE, expr);
4323 /* We should never try to call the abstract or base constructor
4325 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (convfn)
4326 && !DECL_HAS_VTT_PARM_P (convfn));
4327 args = tree_cons (NULL_TREE, t, args);
4330 args = build_this (expr);
4331 expr = build_over_call (cand, LOOKUP_NORMAL);
4333 /* If this is a constructor or a function returning an aggr type,
4334 we need to build up a TARGET_EXPR. */
4335 if (DECL_CONSTRUCTOR_P (convfn))
4336 expr = build_cplus_new (totype, expr);
4338 /* The result of the call is then used to direct-initialize the object
4339 that is the destination of the copy-initialization. [dcl.init]
4341 Note that this step is not reflected in the conversion sequence;
4342 it affects the semantics when we actually perform the
4343 conversion, but is not considered during overload resolution.
4345 If the target is a class, that means call a ctor. */
4346 if (IS_AGGR_TYPE (totype)
4347 && (inner >= 0 || !lvalue_p (expr)))
4351 /* Core issue 84, now a DR, says that we don't
4352 allow UDCs for these args (which deliberately
4353 breaks copy-init of an auto_ptr<Base> from an
4354 auto_ptr<Derived>). */
4355 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4362 (" initializing argument %P of %qD from result of %qD",
4363 argnum, fn, convfn);
4366 (" initializing temporary from result of %qD", convfn);
4368 expr = build_cplus_new (totype, expr);
4373 if (type_unknown_p (expr))
4374 expr = instantiate_type (totype, expr, tf_warning_or_error);
4375 /* Convert a constant to its underlying value, unless we are
4376 about to bind it to a reference, in which case we need to
4377 leave it as an lvalue. */
4379 expr = decl_constant_value (expr);
4380 if (convs->check_copy_constructor_p)
4381 check_constructor_callable (totype, expr);
4384 /* Call build_user_type_conversion again for the error. */
4385 return build_user_type_conversion
4386 (totype, convs->u.expr, LOOKUP_NORMAL);
4392 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4393 convs->kind == ck_ref_bind ? -1 : 1,
4394 /*issue_conversion_warnings=*/false,
4396 if (expr == error_mark_node)
4397 return error_mark_node;
4399 switch (convs->kind)
4402 expr = convert_bitfield_to_declared_type (expr);
4403 if (! IS_AGGR_TYPE (totype))
4405 /* Else fall through. */
4407 if (convs->kind == ck_base && !convs->need_temporary_p)
4409 /* We are going to bind a reference directly to a base-class
4410 subobject of EXPR. */
4411 if (convs->check_copy_constructor_p)
4412 check_constructor_callable (TREE_TYPE (expr), expr);
4413 /* Build an expression for `*((base*) &expr)'. */
4414 expr = build_unary_op (ADDR_EXPR, expr, 0);
4415 expr = convert_to_base (expr, build_pointer_type (totype),
4416 !c_cast_p, /*nonnull=*/true);
4417 expr = build_indirect_ref (expr, "implicit conversion");
4421 /* Copy-initialization where the cv-unqualified version of the source
4422 type is the same class as, or a derived class of, the class of the
4423 destination [is treated as direct-initialization]. [dcl.init] */
4424 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4426 if (diagnostic_fn && fn)
4427 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4428 return build_cplus_new (totype, expr);
4432 tree ref_type = totype;
4434 /* If necessary, create a temporary. */
4435 if (convs->need_temporary_p || !lvalue_p (expr))
4437 tree type = convs->u.next->type;
4438 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4440 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
4442 /* If the reference is volatile or non-const, we
4443 cannot create a temporary. */
4444 if (lvalue & clk_bitfield)
4445 error ("cannot bind bitfield %qE to %qT",
4447 else if (lvalue & clk_packed)
4448 error ("cannot bind packed field %qE to %qT",
4451 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4452 return error_mark_node;
4454 /* If the source is a packed field, and we must use a copy
4455 constructor, then building the target expr will require
4456 binding the field to the reference parameter to the
4457 copy constructor, and we'll end up with an infinite
4458 loop. If we can use a bitwise copy, then we'll be
4460 if ((lvalue & clk_packed)
4461 && CLASS_TYPE_P (type)
4462 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4464 error ("cannot bind packed field %qE to %qT",
4466 return error_mark_node;
4468 expr = build_target_expr_with_type (expr, type);
4471 /* Take the address of the thing to which we will bind the
4473 expr = build_unary_op (ADDR_EXPR, expr, 1);
4474 if (expr == error_mark_node)
4475 return error_mark_node;
4477 /* Convert it to a pointer to the type referred to by the
4478 reference. This will adjust the pointer if a derived to
4479 base conversion is being performed. */
4480 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4482 /* Convert the pointer to the desired reference type. */
4483 return build_nop (ref_type, expr);
4487 return decay_conversion (expr);
4490 /* Warn about deprecated conversion if appropriate. */
4491 string_conv_p (totype, expr, 1);
4496 expr = convert_to_base (expr, totype, !c_cast_p,
4498 return build_nop (totype, expr);
4501 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4508 if (issue_conversion_warnings)
4509 expr = convert_and_check (totype, expr);
4511 expr = convert (totype, expr);
4516 /* Build a call to __builtin_trap. */
4519 call_builtin_trap (void)
4521 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4523 gcc_assert (fn != NULL);
4524 fn = build_call (fn, NULL_TREE);
4528 /* ARG is being passed to a varargs function. Perform any conversions
4529 required. Return the converted value. */
4532 convert_arg_to_ellipsis (tree arg)
4536 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4537 standard conversions are performed. */
4538 arg = decay_conversion (arg);
4541 If the argument has integral or enumeration type that is subject
4542 to the integral promotions (_conv.prom_), or a floating point
4543 type that is subject to the floating point promotion
4544 (_conv.fpprom_), the value of the argument is converted to the
4545 promoted type before the call. */
4546 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4547 && (TYPE_PRECISION (TREE_TYPE (arg))
4548 < TYPE_PRECISION (double_type_node)))
4549 arg = convert_to_real (double_type_node, arg);
4550 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4551 arg = perform_integral_promotions (arg);
4553 arg = require_complete_type (arg);
4555 if (arg != error_mark_node
4556 && !pod_type_p (TREE_TYPE (arg)))
4558 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4559 here and do a bitwise copy, but now cp_expr_size will abort if we
4561 If the call appears in the context of a sizeof expression,
4562 there is no need to emit a warning, since the expression won't be
4563 evaluated. We keep the builtin_trap just as a safety check. */
4564 if (!skip_evaluation)
4565 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4566 "call will abort at runtime", TREE_TYPE (arg));
4567 arg = call_builtin_trap ();
4568 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4575 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4578 build_x_va_arg (tree expr, tree type)
4580 if (processing_template_decl)
4581 return build_min (VA_ARG_EXPR, type, expr);
4583 type = complete_type_or_else (type, NULL_TREE);
4585 if (expr == error_mark_node || !type)
4586 return error_mark_node;
4588 if (! pod_type_p (type))
4590 /* Remove reference types so we don't ICE later on. */
4591 tree type1 = non_reference (type);
4592 /* Undefined behavior [expr.call] 5.2.2/7. */
4593 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4594 "call will abort at runtime", type);
4595 expr = convert (build_pointer_type (type1), null_node);
4596 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4597 call_builtin_trap (), expr);
4598 expr = build_indirect_ref (expr, NULL);
4602 return build_va_arg (expr, type);
4605 /* TYPE has been given to va_arg. Apply the default conversions which
4606 would have happened when passed via ellipsis. Return the promoted
4607 type, or the passed type if there is no change. */
4610 cxx_type_promotes_to (tree type)
4614 /* Perform the array-to-pointer and function-to-pointer
4616 type = type_decays_to (type);
4618 promote = type_promotes_to (type);
4619 if (same_type_p (type, promote))
4625 /* ARG is a default argument expression being passed to a parameter of
4626 the indicated TYPE, which is a parameter to FN. Do any required
4627 conversions. Return the converted value. */
4630 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4632 /* If the ARG is an unparsed default argument expression, the
4633 conversion cannot be performed. */
4634 if (TREE_CODE (arg) == DEFAULT_ARG)
4636 error ("the default argument for parameter %d of %qD has "
4637 "not yet been parsed",
4639 return error_mark_node;
4642 if (fn && DECL_TEMPLATE_INFO (fn))
4643 arg = tsubst_default_argument (fn, type, arg);
4645 arg = break_out_target_exprs (arg);
4647 if (TREE_CODE (arg) == CONSTRUCTOR)
4649 arg = digest_init (type, arg);
4650 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4651 "default argument", fn, parmnum);
4655 /* We must make a copy of ARG, in case subsequent processing
4656 alters any part of it. For example, during gimplification a
4657 cast of the form (T) &X::f (where "f" is a member function)
4658 will lead to replacing the PTRMEM_CST for &X::f with a
4659 VAR_DECL. We can avoid the copy for constants, since they
4660 are never modified in place. */
4661 if (!CONSTANT_CLASS_P (arg))
4662 arg = unshare_expr (arg);
4663 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4664 "default argument", fn, parmnum);
4665 arg = convert_for_arg_passing (type, arg);
4671 /* Returns the type which will really be used for passing an argument of
4675 type_passed_as (tree type)
4677 /* Pass classes with copy ctors by invisible reference. */
4678 if (TREE_ADDRESSABLE (type))
4680 type = build_reference_type (type);
4681 /* There are no other pointers to this temporary. */
4682 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4684 else if (targetm.calls.promote_prototypes (type)
4685 && INTEGRAL_TYPE_P (type)
4686 && COMPLETE_TYPE_P (type)
4687 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4688 TYPE_SIZE (integer_type_node)))
4689 type = integer_type_node;
4694 /* Actually perform the appropriate conversion. */
4697 convert_for_arg_passing (tree type, tree val)
4701 /* If VAL is a bitfield, then -- since it has already been converted
4702 to TYPE -- it cannot have a precision greater than TYPE.
4704 If it has a smaller precision, we must widen it here. For
4705 example, passing "int f:3;" to a function expecting an "int" will
4706 not result in any conversion before this point.
4708 If the precision is the same we must not risk widening. For
4709 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
4710 often have type "int", even though the C++ type for the field is
4711 "long long". If the value is being passed to a function
4712 expecting an "int", then no conversions will be required. But,
4713 if we call convert_bitfield_to_declared_type, the bitfield will
4714 be converted to "long long". */
4715 bitfield_type = is_bitfield_expr_with_lowered_type (val);
4717 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
4718 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
4720 if (val == error_mark_node)
4722 /* Pass classes with copy ctors by invisible reference. */
4723 else if (TREE_ADDRESSABLE (type))
4724 val = build1 (ADDR_EXPR, build_reference_type (type), val);
4725 else if (targetm.calls.promote_prototypes (type)
4726 && INTEGRAL_TYPE_P (type)
4727 && COMPLETE_TYPE_P (type)
4728 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4729 TYPE_SIZE (integer_type_node)))
4730 val = perform_integral_promotions (val);
4731 if (warn_missing_format_attribute)
4733 tree rhstype = TREE_TYPE (val);
4734 const enum tree_code coder = TREE_CODE (rhstype);
4735 const enum tree_code codel = TREE_CODE (type);
4736 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4738 && check_missing_format_attribute (type, rhstype))
4739 warning (OPT_Wmissing_format_attribute,
4740 "argument of function call might be a candidate for a format attribute");
4745 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4746 which no conversions at all should be done. This is true for some
4747 builtins which don't act like normal functions. */
4750 magic_varargs_p (tree fn)
4752 if (DECL_BUILT_IN (fn))
4753 switch (DECL_FUNCTION_CODE (fn))
4755 case BUILT_IN_CLASSIFY_TYPE:
4756 case BUILT_IN_CONSTANT_P:
4757 case BUILT_IN_NEXT_ARG:
4758 case BUILT_IN_STDARG_START:
4759 case BUILT_IN_VA_START:
4768 /* Subroutine of the various build_*_call functions. Overload resolution
4769 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4770 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4771 bitmask of various LOOKUP_* flags which apply to the call itself. */
4774 build_over_call (struct z_candidate *cand, int flags)
4777 tree args = cand->args;
4778 conversion **convs = cand->convs;
4780 tree converted_args = NULL_TREE;
4781 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4786 /* In a template, there is no need to perform all of the work that
4787 is normally done. We are only interested in the type of the call
4788 expression, i.e., the return type of the function. Any semantic
4789 errors will be deferred until the template is instantiated. */
4790 if (processing_template_decl)
4794 return_type = TREE_TYPE (TREE_TYPE (fn));
4795 expr = build3 (CALL_EXPR, return_type, fn, args, NULL_TREE);
4796 if (TREE_THIS_VOLATILE (fn) && cfun)
4797 current_function_returns_abnormally = 1;
4798 if (!VOID_TYPE_P (return_type))
4799 require_complete_type (return_type);
4800 return convert_from_reference (expr);
4803 /* Give any warnings we noticed during overload resolution. */
4806 struct candidate_warning *w;
4807 for (w = cand->warnings; w; w = w->next)
4808 joust (cand, w->loser, 1);
4811 if (DECL_FUNCTION_MEMBER_P (fn))
4813 /* If FN is a template function, two cases must be considered.
4818 template <class T> void f();
4820 template <class T> struct B {
4824 struct C : A, B<int> {
4826 using B<int>::g; // #2
4829 In case #1 where `A::f' is a member template, DECL_ACCESS is
4830 recorded in the primary template but not in its specialization.
4831 We check access of FN using its primary template.
4833 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4834 because it is a member of class template B, DECL_ACCESS is
4835 recorded in the specialization `B<int>::g'. We cannot use its
4836 primary template because `B<T>::g' and `B<int>::g' may have
4837 different access. */
4838 if (DECL_TEMPLATE_INFO (fn)
4839 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4840 perform_or_defer_access_check (cand->access_path,
4841 DECL_TI_TEMPLATE (fn), fn);
4843 perform_or_defer_access_check (cand->access_path, fn, fn);
4846 if (args && TREE_CODE (args) != TREE_LIST)
4847 args = build_tree_list (NULL_TREE, args);
4850 /* The implicit parameters to a constructor are not considered by overload
4851 resolution, and must be of the proper type. */
4852 if (DECL_CONSTRUCTOR_P (fn))
4854 converted_args = tree_cons (NULL_TREE, TREE_VALUE (arg), converted_args);
4855 arg = TREE_CHAIN (arg);
4856 parm = TREE_CHAIN (parm);
4857 /* We should never try to call the abstract constructor. */
4858 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4860 if (DECL_HAS_VTT_PARM_P (fn))
4862 converted_args = tree_cons
4863 (NULL_TREE, TREE_VALUE (arg), converted_args);
4864 arg = TREE_CHAIN (arg);
4865 parm = TREE_CHAIN (parm);
4868 /* Bypass access control for 'this' parameter. */
4869 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4871 tree parmtype = TREE_VALUE (parm);
4872 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4876 if (convs[i]->bad_p)
4877 pedwarn ("passing %qT as %<this%> argument of %q#D discards qualifiers",
4878 TREE_TYPE (argtype), fn);
4880 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4881 X is called for an object that is not of type X, or of a type
4882 derived from X, the behavior is undefined.
4884 So we can assume that anything passed as 'this' is non-null, and
4885 optimize accordingly. */
4886 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4887 /* Convert to the base in which the function was declared. */
4888 gcc_assert (cand->conversion_path != NULL_TREE);
4889 converted_arg = build_base_path (PLUS_EXPR,
4891 cand->conversion_path,
4893 /* Check that the base class is accessible. */
4894 if (!accessible_base_p (TREE_TYPE (argtype),
4895 BINFO_TYPE (cand->conversion_path), true))
4896 error ("%qT is not an accessible base of %qT",
4897 BINFO_TYPE (cand->conversion_path),
4898 TREE_TYPE (argtype));
4899 /* If fn was found by a using declaration, the conversion path
4900 will be to the derived class, not the base declaring fn. We
4901 must convert from derived to base. */
4902 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4903 TREE_TYPE (parmtype), ba_unique, NULL);
4904 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4907 converted_args = tree_cons (NULL_TREE, converted_arg, converted_args);
4908 parm = TREE_CHAIN (parm);
4909 arg = TREE_CHAIN (arg);
4915 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4917 tree type = TREE_VALUE (parm);
4921 /* Don't make a copy here if build_call is going to. */
4922 if (conv->kind == ck_rvalue
4923 && !TREE_ADDRESSABLE (complete_type (type)))
4924 conv = conv->u.next;
4926 val = convert_like_with_context
4927 (conv, TREE_VALUE (arg), fn, i - is_method);
4929 val = convert_for_arg_passing (type, val);
4930 converted_args = tree_cons (NULL_TREE, val, converted_args);
4933 /* Default arguments */
4934 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
4936 = tree_cons (NULL_TREE,
4937 convert_default_arg (TREE_VALUE (parm),
4938 TREE_PURPOSE (parm),
4943 for (; arg; arg = TREE_CHAIN (arg))
4945 tree a = TREE_VALUE (arg);
4946 if (magic_varargs_p (fn))
4947 /* Do no conversions for magic varargs. */;
4949 a = convert_arg_to_ellipsis (a);
4950 converted_args = tree_cons (NULL_TREE, a, converted_args);
4953 converted_args = nreverse (converted_args);
4955 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
4956 converted_args, TYPE_ARG_TYPES (TREE_TYPE (fn)));
4958 /* Avoid actually calling copy constructors and copy assignment operators,
4961 if (! flag_elide_constructors)
4962 /* Do things the hard way. */;
4963 else if (cand->num_convs == 1 && DECL_COPY_CONSTRUCTOR_P (fn))
4966 arg = skip_artificial_parms_for (fn, converted_args);
4967 arg = TREE_VALUE (arg);
4969 /* Pull out the real argument, disregarding const-correctness. */
4971 while (TREE_CODE (targ) == NOP_EXPR
4972 || TREE_CODE (targ) == NON_LVALUE_EXPR
4973 || TREE_CODE (targ) == CONVERT_EXPR)
4974 targ = TREE_OPERAND (targ, 0);
4975 if (TREE_CODE (targ) == ADDR_EXPR)
4977 targ = TREE_OPERAND (targ, 0);
4978 if (!same_type_ignoring_top_level_qualifiers_p
4979 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
4988 arg = build_indirect_ref (arg, 0);
4990 /* [class.copy]: the copy constructor is implicitly defined even if
4991 the implementation elided its use. */
4992 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
4995 /* If we're creating a temp and we already have one, don't create a
4996 new one. If we're not creating a temp but we get one, use
4997 INIT_EXPR to collapse the temp into our target. Otherwise, if the
4998 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
4999 temp or an INIT_EXPR otherwise. */
5000 if (integer_zerop (TREE_VALUE (args)))
5002 if (TREE_CODE (arg) == TARGET_EXPR)
5004 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5005 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
5007 else if (TREE_CODE (arg) == TARGET_EXPR
5008 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5010 tree to = stabilize_reference
5011 (build_indirect_ref (TREE_VALUE (args), 0));
5013 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
5017 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
5019 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
5021 tree to = stabilize_reference
5022 (build_indirect_ref (TREE_VALUE (converted_args), 0));
5023 tree type = TREE_TYPE (to);
5024 tree as_base = CLASSTYPE_AS_BASE (type);
5026 arg = TREE_VALUE (TREE_CHAIN (converted_args));
5027 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
5029 arg = build_indirect_ref (arg, 0);
5030 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
5034 /* We must only copy the non-tail padding parts.
5035 Use __builtin_memcpy for the bitwise copy. */
5039 args = tree_cons (NULL, TYPE_SIZE_UNIT (as_base), NULL);
5040 args = tree_cons (NULL, arg, args);
5041 t = build_unary_op (ADDR_EXPR, to, 0);
5042 args = tree_cons (NULL, t, args);
5043 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
5044 t = build_call (t, args);
5046 t = convert (TREE_TYPE (TREE_VALUE (args)), t);
5047 val = build_indirect_ref (t, 0);
5055 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
5057 tree t, *p = &TREE_VALUE (converted_args);
5058 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (*p)),
5061 gcc_assert (binfo && binfo != error_mark_node);
5063 *p = build_base_path (PLUS_EXPR, *p, binfo, 1);
5064 if (TREE_SIDE_EFFECTS (*p))
5065 *p = save_expr (*p);
5066 t = build_pointer_type (TREE_TYPE (fn));
5067 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5068 fn = build_java_interface_fn_ref (fn, *p);
5070 fn = build_vfn_ref (*p, DECL_VINDEX (fn));
5073 else if (DECL_INLINE (fn))
5074 fn = inline_conversion (fn);
5076 fn = build_addr_func (fn);
5078 return build_cxx_call (fn, converted_args);
5081 /* Build and return a call to FN, using ARGS. This function performs
5082 no overload resolution, conversion, or other high-level
5086 build_cxx_call (tree fn, tree args)
5090 fn = build_call (fn, args);
5092 /* If this call might throw an exception, note that fact. */
5093 fndecl = get_callee_fndecl (fn);
5094 if ((!fndecl || !TREE_NOTHROW (fndecl))
5095 && at_function_scope_p ()
5097 cp_function_chain->can_throw = 1;
5099 /* Some built-in function calls will be evaluated at compile-time in
5101 fn = fold_if_not_in_template (fn);
5103 if (VOID_TYPE_P (TREE_TYPE (fn)))
5106 fn = require_complete_type (fn);
5107 if (fn == error_mark_node)
5108 return error_mark_node;
5110 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
5111 fn = build_cplus_new (TREE_TYPE (fn), fn);
5112 return convert_from_reference (fn);
5115 static GTY(()) tree java_iface_lookup_fn;
5117 /* Make an expression which yields the address of the Java interface
5118 method FN. This is achieved by generating a call to libjava's
5119 _Jv_LookupInterfaceMethodIdx(). */
5122 build_java_interface_fn_ref (tree fn, tree instance)
5124 tree lookup_args, lookup_fn, method, idx;
5125 tree klass_ref, iface, iface_ref;
5128 if (!java_iface_lookup_fn)
5130 tree endlink = build_void_list_node ();
5131 tree t = tree_cons (NULL_TREE, ptr_type_node,
5132 tree_cons (NULL_TREE, ptr_type_node,
5133 tree_cons (NULL_TREE, java_int_type_node,
5135 java_iface_lookup_fn
5136 = builtin_function ("_Jv_LookupInterfaceMethodIdx",
5137 build_function_type (ptr_type_node, t),
5138 0, NOT_BUILT_IN, NULL, NULL_TREE);
5141 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5142 This is the first entry in the vtable. */
5143 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
5146 /* Get the java.lang.Class pointer for the interface being called. */
5147 iface = DECL_CONTEXT (fn);
5148 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5149 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5150 || DECL_CONTEXT (iface_ref) != iface)
5152 error ("could not find class$ field in java interface type %qT",
5154 return error_mark_node;
5156 iface_ref = build_address (iface_ref);
5157 iface_ref = convert (build_pointer_type (iface), iface_ref);
5159 /* Determine the itable index of FN. */
5161 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5163 if (!DECL_VIRTUAL_P (method))
5169 idx = build_int_cst (NULL_TREE, i);
5171 lookup_args = tree_cons (NULL_TREE, klass_ref,
5172 tree_cons (NULL_TREE, iface_ref,
5173 build_tree_list (NULL_TREE, idx)));
5174 lookup_fn = build1 (ADDR_EXPR,
5175 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5176 java_iface_lookup_fn);
5177 return build3 (CALL_EXPR, ptr_type_node, lookup_fn, lookup_args, NULL_TREE);
5180 /* Returns the value to use for the in-charge parameter when making a
5181 call to a function with the indicated NAME.
5183 FIXME:Can't we find a neater way to do this mapping? */
5186 in_charge_arg_for_name (tree name)
5188 if (name == base_ctor_identifier
5189 || name == base_dtor_identifier)
5190 return integer_zero_node;
5191 else if (name == complete_ctor_identifier)
5192 return integer_one_node;
5193 else if (name == complete_dtor_identifier)
5194 return integer_two_node;
5195 else if (name == deleting_dtor_identifier)
5196 return integer_three_node;
5198 /* This function should only be called with one of the names listed
5204 /* Build a call to a constructor, destructor, or an assignment
5205 operator for INSTANCE, an expression with class type. NAME
5206 indicates the special member function to call; ARGS are the
5207 arguments. BINFO indicates the base of INSTANCE that is to be
5208 passed as the `this' parameter to the member function called.
5210 FLAGS are the LOOKUP_* flags to use when processing the call.
5212 If NAME indicates a complete object constructor, INSTANCE may be
5213 NULL_TREE. In this case, the caller will call build_cplus_new to
5214 store the newly constructed object into a VAR_DECL. */
5217 build_special_member_call (tree instance, tree name, tree args,
5218 tree binfo, int flags)
5221 /* The type of the subobject to be constructed or destroyed. */
5224 gcc_assert (name == complete_ctor_identifier
5225 || name == base_ctor_identifier
5226 || name == complete_dtor_identifier
5227 || name == base_dtor_identifier
5228 || name == deleting_dtor_identifier
5229 || name == ansi_assopname (NOP_EXPR));
5232 /* Resolve the name. */
5233 if (!complete_type_or_else (binfo, NULL_TREE))
5234 return error_mark_node;
5236 binfo = TYPE_BINFO (binfo);
5239 gcc_assert (binfo != NULL_TREE);
5241 class_type = BINFO_TYPE (binfo);
5243 /* Handle the special case where INSTANCE is NULL_TREE. */
5244 if (name == complete_ctor_identifier && !instance)
5246 instance = build_int_cst (build_pointer_type (class_type), 0);
5247 instance = build1 (INDIRECT_REF, class_type, instance);
5251 if (name == complete_dtor_identifier
5252 || name == base_dtor_identifier
5253 || name == deleting_dtor_identifier)
5254 gcc_assert (args == NULL_TREE);
5256 /* Convert to the base class, if necessary. */
5257 if (!same_type_ignoring_top_level_qualifiers_p
5258 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5260 if (name != ansi_assopname (NOP_EXPR))
5261 /* For constructors and destructors, either the base is
5262 non-virtual, or it is virtual but we are doing the
5263 conversion from a constructor or destructor for the
5264 complete object. In either case, we can convert
5266 instance = convert_to_base_statically (instance, binfo);
5268 /* However, for assignment operators, we must convert
5269 dynamically if the base is virtual. */
5270 instance = build_base_path (PLUS_EXPR, instance,
5271 binfo, /*nonnull=*/1);
5275 gcc_assert (instance != NULL_TREE);
5277 fns = lookup_fnfields (binfo, name, 1);
5279 /* When making a call to a constructor or destructor for a subobject
5280 that uses virtual base classes, pass down a pointer to a VTT for
5282 if ((name == base_ctor_identifier
5283 || name == base_dtor_identifier)
5284 && CLASSTYPE_VBASECLASSES (class_type))
5289 /* If the current function is a complete object constructor
5290 or destructor, then we fetch the VTT directly.
5291 Otherwise, we look it up using the VTT we were given. */
5292 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5293 vtt = decay_conversion (vtt);
5294 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5295 build2 (EQ_EXPR, boolean_type_node,
5296 current_in_charge_parm, integer_zero_node),
5299 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5300 sub_vtt = build2 (PLUS_EXPR, TREE_TYPE (vtt), vtt,
5301 BINFO_SUBVTT_INDEX (binfo));
5303 args = tree_cons (NULL_TREE, sub_vtt, args);
5306 return build_new_method_call (instance, fns, args,
5307 TYPE_BINFO (BINFO_TYPE (binfo)),
5308 flags, /*fn=*/NULL);
5311 /* Return the NAME, as a C string. The NAME indicates a function that
5312 is a member of TYPE. *FREE_P is set to true if the caller must
5313 free the memory returned.
5315 Rather than go through all of this, we should simply set the names
5316 of constructors and destructors appropriately, and dispense with
5317 ctor_identifier, dtor_identifier, etc. */
5320 name_as_c_string (tree name, tree type, bool *free_p)
5324 /* Assume that we will not allocate memory. */
5326 /* Constructors and destructors are special. */
5327 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5330 = (char *) IDENTIFIER_POINTER (constructor_name (type));
5331 /* For a destructor, add the '~'. */
5332 if (name == complete_dtor_identifier
5333 || name == base_dtor_identifier
5334 || name == deleting_dtor_identifier)
5336 pretty_name = concat ("~", pretty_name, NULL);
5337 /* Remember that we need to free the memory allocated. */
5341 else if (IDENTIFIER_TYPENAME_P (name))
5343 pretty_name = concat ("operator ",
5344 type_as_string (TREE_TYPE (name),
5345 TFF_PLAIN_IDENTIFIER),
5347 /* Remember that we need to free the memory allocated. */
5351 pretty_name = (char *) IDENTIFIER_POINTER (name);
5356 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5357 be set, upon return, to the function called. */
5360 build_new_method_call (tree instance, tree fns, tree args,
5361 tree conversion_path, int flags,
5364 struct z_candidate *candidates = 0, *cand;
5365 tree explicit_targs = NULL_TREE;
5366 tree basetype = NULL_TREE;
5369 tree mem_args = NULL_TREE, instance_ptr;
5375 int template_only = 0;
5382 gcc_assert (instance != NULL_TREE);
5384 /* We don't know what function we're going to call, yet. */
5388 if (error_operand_p (instance)
5389 || error_operand_p (fns)
5390 || args == error_mark_node)
5391 return error_mark_node;
5393 if (!BASELINK_P (fns))
5395 error ("call to non-function %qD", fns);
5396 return error_mark_node;
5399 orig_instance = instance;
5403 /* Dismantle the baselink to collect all the information we need. */
5404 if (!conversion_path)
5405 conversion_path = BASELINK_BINFO (fns);
5406 access_binfo = BASELINK_ACCESS_BINFO (fns);
5407 optype = BASELINK_OPTYPE (fns);
5408 fns = BASELINK_FUNCTIONS (fns);
5409 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5411 explicit_targs = TREE_OPERAND (fns, 1);
5412 fns = TREE_OPERAND (fns, 0);
5415 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5416 || TREE_CODE (fns) == TEMPLATE_DECL
5417 || TREE_CODE (fns) == OVERLOAD);
5418 fn = get_first_fn (fns);
5419 name = DECL_NAME (fn);
5421 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5422 gcc_assert (CLASS_TYPE_P (basetype));
5424 if (processing_template_decl)
5426 instance = build_non_dependent_expr (instance);
5427 args = build_non_dependent_args (orig_args);
5430 /* The USER_ARGS are the arguments we will display to users if an
5431 error occurs. The USER_ARGS should not include any
5432 compiler-generated arguments. The "this" pointer hasn't been
5433 added yet. However, we must remove the VTT pointer if this is a
5434 call to a base-class constructor or destructor. */
5436 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5438 /* Callers should explicitly indicate whether they want to construct
5439 the complete object or just the part without virtual bases. */
5440 gcc_assert (name != ctor_identifier);
5441 /* Similarly for destructors. */
5442 gcc_assert (name != dtor_identifier);
5443 /* Remove the VTT pointer, if present. */
5444 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5445 && CLASSTYPE_VBASECLASSES (basetype))
5446 user_args = TREE_CHAIN (user_args);
5449 /* Process the argument list. */
5450 args = resolve_args (args);
5451 if (args == error_mark_node)
5452 return error_mark_node;
5454 instance_ptr = build_this (instance);
5456 /* It's OK to call destructors on cv-qualified objects. Therefore,
5457 convert the INSTANCE_PTR to the unqualified type, if necessary. */
5458 if (DECL_DESTRUCTOR_P (fn))
5460 tree type = build_pointer_type (basetype);
5461 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5462 instance_ptr = build_nop (type, instance_ptr);
5463 name = complete_dtor_identifier;
5466 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5467 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5469 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5470 p = conversion_obstack_alloc (0);
5472 for (fn = fns; fn; fn = OVL_NEXT (fn))
5474 tree t = OVL_CURRENT (fn);
5477 /* We can end up here for copy-init of same or base class. */
5478 if ((flags & LOOKUP_ONLYCONVERTING)
5479 && DECL_NONCONVERTING_P (t))
5482 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5483 this_arglist = mem_args;
5485 this_arglist = args;
5487 if (TREE_CODE (t) == TEMPLATE_DECL)
5488 /* A member template. */
5489 add_template_candidate (&candidates, t,
5492 this_arglist, optype,
5497 else if (! template_only)
5498 add_function_candidate (&candidates, t,
5506 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5509 if (!COMPLETE_TYPE_P (basetype))
5510 cxx_incomplete_type_error (instance_ptr, basetype);
5516 pretty_name = name_as_c_string (name, basetype, &free_p);
5517 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5518 basetype, pretty_name, user_args,
5519 TREE_TYPE (TREE_TYPE (instance_ptr)));
5523 print_z_candidates (candidates);
5524 call = error_mark_node;
5528 cand = tourney (candidates);
5534 pretty_name = name_as_c_string (name, basetype, &free_p);
5535 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5537 print_z_candidates (candidates);
5540 call = error_mark_node;
5546 if (!(flags & LOOKUP_NONVIRTUAL)
5547 && DECL_PURE_VIRTUAL_P (fn)
5548 && instance == current_class_ref
5549 && (DECL_CONSTRUCTOR_P (current_function_decl)
5550 || DECL_DESTRUCTOR_P (current_function_decl)))
5551 /* This is not an error, it is runtime undefined
5553 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
5554 "abstract virtual %q#D called from constructor"
5555 : "abstract virtual %q#D called from destructor"),
5558 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
5559 && is_dummy_object (instance_ptr))
5561 error ("cannot call member function %qD without object",
5563 call = error_mark_node;
5567 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
5568 && resolves_to_fixed_type_p (instance, 0))
5569 flags |= LOOKUP_NONVIRTUAL;
5570 /* Now we know what function is being called. */
5573 /* Build the actual CALL_EXPR. */
5574 call = build_over_call (cand, flags);
5575 /* In an expression of the form `a->f()' where `f' turns
5576 out to be a static member function, `a' is
5577 none-the-less evaluated. */
5578 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
5579 && !is_dummy_object (instance_ptr)
5580 && TREE_SIDE_EFFECTS (instance_ptr))
5581 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5582 instance_ptr, call);
5583 else if (call != error_mark_node
5584 && DECL_DESTRUCTOR_P (cand->fn)
5585 && !VOID_TYPE_P (TREE_TYPE (call)))
5586 /* An explicit call of the form "x->~X()" has type
5587 "void". However, on platforms where destructors
5588 return "this" (i.e., those where
5589 targetm.cxx.cdtor_returns_this is true), such calls
5590 will appear to have a return value of pointer type
5591 to the low-level call machinery. We do not want to
5592 change the low-level machinery, since we want to be
5593 able to optimize "delete f()" on such platforms as
5594 "operator delete(~X(f()))" (rather than generating
5595 "t = f(), ~X(t), operator delete (t)"). */
5596 call = build_nop (void_type_node, call);
5601 if (processing_template_decl && call != error_mark_node)
5602 call = (build_min_non_dep
5604 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5605 orig_args, NULL_TREE));
5607 /* Free all the conversions we allocated. */
5608 obstack_free (&conversion_obstack, p);
5613 /* Returns true iff standard conversion sequence ICS1 is a proper
5614 subsequence of ICS2. */
5617 is_subseq (conversion *ics1, conversion *ics2)
5619 /* We can assume that a conversion of the same code
5620 between the same types indicates a subsequence since we only get
5621 here if the types we are converting from are the same. */
5623 while (ics1->kind == ck_rvalue
5624 || ics1->kind == ck_lvalue)
5625 ics1 = ics1->u.next;
5629 while (ics2->kind == ck_rvalue
5630 || ics2->kind == ck_lvalue)
5631 ics2 = ics2->u.next;
5633 if (ics2->kind == ck_user
5634 || ics2->kind == ck_ambig
5635 || ics2->kind == ck_identity)
5636 /* At this point, ICS1 cannot be a proper subsequence of
5637 ICS2. We can get a USER_CONV when we are comparing the
5638 second standard conversion sequence of two user conversion
5642 ics2 = ics2->u.next;
5644 if (ics2->kind == ics1->kind
5645 && same_type_p (ics2->type, ics1->type)
5646 && same_type_p (ics2->u.next->type,
5647 ics1->u.next->type))
5652 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5653 be any _TYPE nodes. */
5656 is_properly_derived_from (tree derived, tree base)
5658 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5659 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5662 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5663 considers every class derived from itself. */
5664 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5665 && DERIVED_FROM_P (base, derived));
5668 /* We build the ICS for an implicit object parameter as a pointer
5669 conversion sequence. However, such a sequence should be compared
5670 as if it were a reference conversion sequence. If ICS is the
5671 implicit conversion sequence for an implicit object parameter,
5672 modify it accordingly. */
5675 maybe_handle_implicit_object (conversion **ics)
5679 /* [over.match.funcs]
5681 For non-static member functions, the type of the
5682 implicit object parameter is "reference to cv X"
5683 where X is the class of which the function is a
5684 member and cv is the cv-qualification on the member
5685 function declaration. */
5686 conversion *t = *ics;
5687 tree reference_type;
5689 /* The `this' parameter is a pointer to a class type. Make the
5690 implicit conversion talk about a reference to that same class
5692 reference_type = TREE_TYPE (t->type);
5693 reference_type = build_reference_type (reference_type);
5695 if (t->kind == ck_qual)
5697 if (t->kind == ck_ptr)
5699 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5700 t = direct_reference_binding (reference_type, t);
5705 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5706 and return the type to which the reference refers. Otherwise,
5707 leave *ICS unchanged and return NULL_TREE. */
5710 maybe_handle_ref_bind (conversion **ics)
5712 if ((*ics)->kind == ck_ref_bind)
5714 conversion *old_ics = *ics;
5715 tree type = TREE_TYPE (old_ics->type);
5716 *ics = old_ics->u.next;
5717 (*ics)->user_conv_p = old_ics->user_conv_p;
5718 (*ics)->bad_p = old_ics->bad_p;
5725 /* Compare two implicit conversion sequences according to the rules set out in
5726 [over.ics.rank]. Return values:
5728 1: ics1 is better than ics2
5729 -1: ics2 is better than ics1
5730 0: ics1 and ics2 are indistinguishable */
5733 compare_ics (conversion *ics1, conversion *ics2)
5739 tree deref_from_type1 = NULL_TREE;
5740 tree deref_from_type2 = NULL_TREE;
5741 tree deref_to_type1 = NULL_TREE;
5742 tree deref_to_type2 = NULL_TREE;
5743 conversion_rank rank1, rank2;
5745 /* REF_BINDING is nonzero if the result of the conversion sequence
5746 is a reference type. In that case TARGET_TYPE is the
5747 type referred to by the reference. */
5751 /* Handle implicit object parameters. */
5752 maybe_handle_implicit_object (&ics1);
5753 maybe_handle_implicit_object (&ics2);
5755 /* Handle reference parameters. */
5756 target_type1 = maybe_handle_ref_bind (&ics1);
5757 target_type2 = maybe_handle_ref_bind (&ics2);
5761 When comparing the basic forms of implicit conversion sequences (as
5762 defined in _over.best.ics_)
5764 --a standard conversion sequence (_over.ics.scs_) is a better
5765 conversion sequence than a user-defined conversion sequence
5766 or an ellipsis conversion sequence, and
5768 --a user-defined conversion sequence (_over.ics.user_) is a
5769 better conversion sequence than an ellipsis conversion sequence
5770 (_over.ics.ellipsis_). */
5771 rank1 = CONVERSION_RANK (ics1);
5772 rank2 = CONVERSION_RANK (ics2);
5776 else if (rank1 < rank2)
5779 if (rank1 == cr_bad)
5781 /* XXX Isn't this an extension? */
5782 /* Both ICS are bad. We try to make a decision based on what
5783 would have happened if they'd been good. */
5784 if (ics1->user_conv_p > ics2->user_conv_p
5785 || ics1->rank > ics2->rank)
5787 else if (ics1->user_conv_p < ics2->user_conv_p
5788 || ics1->rank < ics2->rank)
5791 /* We couldn't make up our minds; try to figure it out below. */
5794 if (ics1->ellipsis_p)
5795 /* Both conversions are ellipsis conversions. */
5798 /* User-defined conversion sequence U1 is a better conversion sequence
5799 than another user-defined conversion sequence U2 if they contain the
5800 same user-defined conversion operator or constructor and if the sec-
5801 ond standard conversion sequence of U1 is better than the second
5802 standard conversion sequence of U2. */
5804 if (ics1->user_conv_p)
5809 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5810 if (t1->kind == ck_ambig)
5812 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5813 if (t2->kind == ck_ambig)
5816 if (t1->cand->fn != t2->cand->fn)
5819 /* We can just fall through here, after setting up
5820 FROM_TYPE1 and FROM_TYPE2. */
5821 from_type1 = t1->type;
5822 from_type2 = t2->type;
5829 /* We're dealing with two standard conversion sequences.
5833 Standard conversion sequence S1 is a better conversion
5834 sequence than standard conversion sequence S2 if
5836 --S1 is a proper subsequence of S2 (comparing the conversion
5837 sequences in the canonical form defined by _over.ics.scs_,
5838 excluding any Lvalue Transformation; the identity
5839 conversion sequence is considered to be a subsequence of
5840 any non-identity conversion sequence */
5843 while (t1->kind != ck_identity)
5845 from_type1 = t1->type;
5848 while (t2->kind != ck_identity)
5850 from_type2 = t2->type;
5853 if (same_type_p (from_type1, from_type2))
5855 if (is_subseq (ics1, ics2))
5857 if (is_subseq (ics2, ics1))
5860 /* Otherwise, one sequence cannot be a subsequence of the other; they
5861 don't start with the same type. This can happen when comparing the
5862 second standard conversion sequence in two user-defined conversion
5869 --the rank of S1 is better than the rank of S2 (by the rules
5872 Standard conversion sequences are ordered by their ranks: an Exact
5873 Match is a better conversion than a Promotion, which is a better
5874 conversion than a Conversion.
5876 Two conversion sequences with the same rank are indistinguishable
5877 unless one of the following rules applies:
5879 --A conversion that is not a conversion of a pointer, or pointer
5880 to member, to bool is better than another conversion that is such
5883 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5884 so that we do not have to check it explicitly. */
5885 if (ics1->rank < ics2->rank)
5887 else if (ics2->rank < ics1->rank)
5890 to_type1 = ics1->type;
5891 to_type2 = ics2->type;
5893 if (TYPE_PTR_P (from_type1)
5894 && TYPE_PTR_P (from_type2)
5895 && TYPE_PTR_P (to_type1)
5896 && TYPE_PTR_P (to_type2))
5898 deref_from_type1 = TREE_TYPE (from_type1);
5899 deref_from_type2 = TREE_TYPE (from_type2);
5900 deref_to_type1 = TREE_TYPE (to_type1);
5901 deref_to_type2 = TREE_TYPE (to_type2);
5903 /* The rules for pointers to members A::* are just like the rules
5904 for pointers A*, except opposite: if B is derived from A then
5905 A::* converts to B::*, not vice versa. For that reason, we
5906 switch the from_ and to_ variables here. */
5907 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5908 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5909 || (TYPE_PTRMEMFUNC_P (from_type1)
5910 && TYPE_PTRMEMFUNC_P (from_type2)
5911 && TYPE_PTRMEMFUNC_P (to_type1)
5912 && TYPE_PTRMEMFUNC_P (to_type2)))
5914 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5915 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5916 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5917 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5920 if (deref_from_type1 != NULL_TREE
5921 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5922 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5924 /* This was one of the pointer or pointer-like conversions.
5928 --If class B is derived directly or indirectly from class A,
5929 conversion of B* to A* is better than conversion of B* to
5930 void*, and conversion of A* to void* is better than
5931 conversion of B* to void*. */
5932 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5933 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5935 if (is_properly_derived_from (deref_from_type1,
5938 else if (is_properly_derived_from (deref_from_type2,
5942 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
5943 || TREE_CODE (deref_to_type2) == VOID_TYPE)
5945 if (same_type_p (deref_from_type1, deref_from_type2))
5947 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
5949 if (is_properly_derived_from (deref_from_type1,
5953 /* We know that DEREF_TO_TYPE1 is `void' here. */
5954 else if (is_properly_derived_from (deref_from_type1,
5959 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
5960 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
5964 --If class B is derived directly or indirectly from class A
5965 and class C is derived directly or indirectly from B,
5967 --conversion of C* to B* is better than conversion of C* to
5970 --conversion of B* to A* is better than conversion of C* to
5972 if (same_type_p (deref_from_type1, deref_from_type2))
5974 if (is_properly_derived_from (deref_to_type1,
5977 else if (is_properly_derived_from (deref_to_type2,
5981 else if (same_type_p (deref_to_type1, deref_to_type2))
5983 if (is_properly_derived_from (deref_from_type2,
5986 else if (is_properly_derived_from (deref_from_type1,
5992 else if (CLASS_TYPE_P (non_reference (from_type1))
5993 && same_type_p (from_type1, from_type2))
5995 tree from = non_reference (from_type1);
5999 --binding of an expression of type C to a reference of type
6000 B& is better than binding an expression of type C to a
6001 reference of type A&
6003 --conversion of C to B is better than conversion of C to A, */
6004 if (is_properly_derived_from (from, to_type1)
6005 && is_properly_derived_from (from, to_type2))
6007 if (is_properly_derived_from (to_type1, to_type2))
6009 else if (is_properly_derived_from (to_type2, to_type1))
6013 else if (CLASS_TYPE_P (non_reference (to_type1))
6014 && same_type_p (to_type1, to_type2))
6016 tree to = non_reference (to_type1);
6020 --binding of an expression of type B to a reference of type
6021 A& is better than binding an expression of type C to a
6022 reference of type A&,
6024 --conversion of B to A is better than conversion of C to A */
6025 if (is_properly_derived_from (from_type1, to)
6026 && is_properly_derived_from (from_type2, to))
6028 if (is_properly_derived_from (from_type2, from_type1))
6030 else if (is_properly_derived_from (from_type1, from_type2))
6037 --S1 and S2 differ only in their qualification conversion and yield
6038 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6039 qualification signature of type T1 is a proper subset of the cv-
6040 qualification signature of type T2 */
6041 if (ics1->kind == ck_qual
6042 && ics2->kind == ck_qual
6043 && same_type_p (from_type1, from_type2))
6044 return comp_cv_qual_signature (to_type1, to_type2);
6048 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6049 types to which the references refer are the same type except for
6050 top-level cv-qualifiers, and the type to which the reference
6051 initialized by S2 refers is more cv-qualified than the type to
6052 which the reference initialized by S1 refers */
6054 if (target_type1 && target_type2
6055 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
6056 return comp_cv_qualification (target_type2, target_type1);
6058 /* Neither conversion sequence is better than the other. */
6062 /* The source type for this standard conversion sequence. */
6065 source_type (conversion *t)
6067 for (;; t = t->u.next)
6069 if (t->kind == ck_user
6070 || t->kind == ck_ambig
6071 || t->kind == ck_identity)
6077 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6078 a pointer to LOSER and re-running joust to produce the warning if WINNER
6079 is actually used. */
6082 add_warning (struct z_candidate *winner, struct z_candidate *loser)
6084 candidate_warning *cw = (candidate_warning *)
6085 conversion_obstack_alloc (sizeof (candidate_warning));
6087 cw->next = winner->warnings;
6088 winner->warnings = cw;
6091 /* Compare two candidates for overloading as described in
6092 [over.match.best]. Return values:
6094 1: cand1 is better than cand2
6095 -1: cand2 is better than cand1
6096 0: cand1 and cand2 are indistinguishable */
6099 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
6102 int off1 = 0, off2 = 0;
6106 /* Candidates that involve bad conversions are always worse than those
6108 if (cand1->viable > cand2->viable)
6110 if (cand1->viable < cand2->viable)
6113 /* If we have two pseudo-candidates for conversions to the same type,
6114 or two candidates for the same function, arbitrarily pick one. */
6115 if (cand1->fn == cand2->fn
6116 && (IS_TYPE_OR_DECL_P (cand1->fn)))
6119 /* a viable function F1
6120 is defined to be a better function than another viable function F2 if
6121 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6122 ICSi(F2), and then */
6124 /* for some argument j, ICSj(F1) is a better conversion sequence than
6127 /* For comparing static and non-static member functions, we ignore
6128 the implicit object parameter of the non-static function. The
6129 standard says to pretend that the static function has an object
6130 parm, but that won't work with operator overloading. */
6131 len = cand1->num_convs;
6132 if (len != cand2->num_convs)
6134 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
6135 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
6137 gcc_assert (static_1 != static_2);
6148 for (i = 0; i < len; ++i)
6150 conversion *t1 = cand1->convs[i + off1];
6151 conversion *t2 = cand2->convs[i + off2];
6152 int comp = compare_ics (t1, t2);
6157 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
6158 == cr_std + cr_promotion)
6159 && t1->kind == ck_std
6160 && t2->kind == ck_std
6161 && TREE_CODE (t1->type) == INTEGER_TYPE
6162 && TREE_CODE (t2->type) == INTEGER_TYPE
6163 && (TYPE_PRECISION (t1->type)
6164 == TYPE_PRECISION (t2->type))
6165 && (TYPE_UNSIGNED (t1->u.next->type)
6166 || (TREE_CODE (t1->u.next->type)
6169 tree type = t1->u.next->type;
6171 struct z_candidate *w, *l;
6173 type1 = t1->type, type2 = t2->type,
6174 w = cand1, l = cand2;
6176 type1 = t2->type, type2 = t1->type,
6177 w = cand2, l = cand1;
6181 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
6182 type, type1, type2);
6183 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
6189 if (winner && comp != winner)
6198 /* warn about confusing overload resolution for user-defined conversions,
6199 either between a constructor and a conversion op, or between two
6201 if (winner && warn_conversion && cand1->second_conv
6202 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
6203 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
6205 struct z_candidate *w, *l;
6206 bool give_warning = false;
6209 w = cand1, l = cand2;
6211 w = cand2, l = cand1;
6213 /* We don't want to complain about `X::operator T1 ()'
6214 beating `X::operator T2 () const', when T2 is a no less
6215 cv-qualified version of T1. */
6216 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
6217 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
6219 tree t = TREE_TYPE (TREE_TYPE (l->fn));
6220 tree f = TREE_TYPE (TREE_TYPE (w->fn));
6222 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6227 if (!comp_ptr_ttypes (t, f))
6228 give_warning = true;
6231 give_warning = true;
6237 tree source = source_type (w->convs[0]);
6238 if (! DECL_CONSTRUCTOR_P (w->fn))
6239 source = TREE_TYPE (source);
6240 warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn);
6241 warning (OPT_Wconversion, " for conversion from %qT to %qT",
6242 source, w->second_conv->type);
6243 inform (" because conversion sequence for the argument is better");
6253 F1 is a non-template function and F2 is a template function
6256 if (!cand1->template_decl && cand2->template_decl)
6258 else if (cand1->template_decl && !cand2->template_decl)
6262 F1 and F2 are template functions and the function template for F1 is
6263 more specialized than the template for F2 according to the partial
6266 if (cand1->template_decl && cand2->template_decl)
6268 winner = more_specialized_fn
6269 (TI_TEMPLATE (cand1->template_decl),
6270 TI_TEMPLATE (cand2->template_decl),
6271 /* [temp.func.order]: The presence of unused ellipsis and default
6272 arguments has no effect on the partial ordering of function
6273 templates. add_function_candidate() will not have
6274 counted the "this" argument for constructors. */
6275 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
6281 the context is an initialization by user-defined conversion (see
6282 _dcl.init_ and _over.match.user_) and the standard conversion
6283 sequence from the return type of F1 to the destination type (i.e.,
6284 the type of the entity being initialized) is a better conversion
6285 sequence than the standard conversion sequence from the return type
6286 of F2 to the destination type. */
6288 if (cand1->second_conv)
6290 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6295 /* Check whether we can discard a builtin candidate, either because we
6296 have two identical ones or matching builtin and non-builtin candidates.
6298 (Pedantically in the latter case the builtin which matched the user
6299 function should not be added to the overload set, but we spot it here.
6302 ... the builtin candidates include ...
6303 - do not have the same parameter type list as any non-template
6304 non-member candidate. */
6306 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6307 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6309 for (i = 0; i < len; ++i)
6310 if (!same_type_p (cand1->convs[i]->type,
6311 cand2->convs[i]->type))
6313 if (i == cand1->num_convs)
6315 if (cand1->fn == cand2->fn)
6316 /* Two built-in candidates; arbitrarily pick one. */
6318 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6319 /* cand1 is built-in; prefer cand2. */
6322 /* cand2 is built-in; prefer cand1. */
6327 /* If the two functions are the same (this can happen with declarations
6328 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6329 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6330 && equal_functions (cand1->fn, cand2->fn))
6335 /* Extension: If the worst conversion for one candidate is worse than the
6336 worst conversion for the other, take the first. */
6339 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6340 struct z_candidate *w = 0, *l = 0;
6342 for (i = 0; i < len; ++i)
6344 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6345 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6346 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6347 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6350 winner = 1, w = cand1, l = cand2;
6352 winner = -1, w = cand2, l = cand1;
6358 ISO C++ says that these are ambiguous, even \
6359 though the worst conversion for the first is better than \
6360 the worst conversion for the second:");
6361 print_z_candidate (_("candidate 1:"), w);
6362 print_z_candidate (_("candidate 2:"), l);
6370 gcc_assert (!winner);
6374 /* Given a list of candidates for overloading, find the best one, if any.
6375 This algorithm has a worst case of O(2n) (winner is last), and a best
6376 case of O(n/2) (totally ambiguous); much better than a sorting
6379 static struct z_candidate *
6380 tourney (struct z_candidate *candidates)
6382 struct z_candidate *champ = candidates, *challenger;
6384 int champ_compared_to_predecessor = 0;
6386 /* Walk through the list once, comparing each current champ to the next
6387 candidate, knocking out a candidate or two with each comparison. */
6389 for (challenger = champ->next; challenger; )
6391 fate = joust (champ, challenger, 0);
6393 challenger = challenger->next;
6398 champ = challenger->next;
6401 champ_compared_to_predecessor = 0;
6406 champ_compared_to_predecessor = 1;
6409 challenger = champ->next;
6413 /* Make sure the champ is better than all the candidates it hasn't yet
6414 been compared to. */
6416 for (challenger = candidates;
6418 && !(champ_compared_to_predecessor && challenger->next == champ);
6419 challenger = challenger->next)
6421 fate = joust (champ, challenger, 0);
6429 /* Returns nonzero if things of type FROM can be converted to TO. */
6432 can_convert (tree to, tree from)
6434 return can_convert_arg (to, from, NULL_TREE, LOOKUP_NORMAL);
6437 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6440 can_convert_arg (tree to, tree from, tree arg, int flags)
6446 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6447 p = conversion_obstack_alloc (0);
6449 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6451 ok_p = (t && !t->bad_p);
6453 /* Free all the conversions we allocated. */
6454 obstack_free (&conversion_obstack, p);
6459 /* Like can_convert_arg, but allows dubious conversions as well. */
6462 can_convert_arg_bad (tree to, tree from, tree arg)
6467 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6468 p = conversion_obstack_alloc (0);
6469 /* Try to perform the conversion. */
6470 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6472 /* Free all the conversions we allocated. */
6473 obstack_free (&conversion_obstack, p);
6478 /* Convert EXPR to TYPE. Return the converted expression.
6480 Note that we allow bad conversions here because by the time we get to
6481 this point we are committed to doing the conversion. If we end up
6482 doing a bad conversion, convert_like will complain. */
6485 perform_implicit_conversion (tree type, tree expr)
6490 if (error_operand_p (expr))
6491 return error_mark_node;
6493 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6494 p = conversion_obstack_alloc (0);
6496 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6501 error ("could not convert %qE to %qT", expr, type);
6502 expr = error_mark_node;
6504 else if (processing_template_decl)
6506 /* In a template, we are only concerned about determining the
6507 type of non-dependent expressions, so we do not have to
6508 perform the actual conversion. */
6509 if (TREE_TYPE (expr) != type)
6510 expr = build_nop (type, expr);
6513 expr = convert_like (conv, expr);
6515 /* Free all the conversions we allocated. */
6516 obstack_free (&conversion_obstack, p);
6521 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6522 permitted. If the conversion is valid, the converted expression is
6523 returned. Otherwise, NULL_TREE is returned, except in the case
6524 that TYPE is a class type; in that case, an error is issued. If
6525 C_CAST_P is true, then this direction initialization is taking
6526 place as part of a static_cast being attempted as part of a C-style
6530 perform_direct_initialization_if_possible (tree type,
6537 if (type == error_mark_node || error_operand_p (expr))
6538 return error_mark_node;
6541 If the destination type is a (possibly cv-qualified) class type:
6543 -- If the initialization is direct-initialization ...,
6544 constructors are considered. ... If no constructor applies, or
6545 the overload resolution is ambiguous, the initialization is
6547 if (CLASS_TYPE_P (type))
6549 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6550 build_tree_list (NULL_TREE, expr),
6551 type, LOOKUP_NORMAL);
6552 return build_cplus_new (type, expr);
6555 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6556 p = conversion_obstack_alloc (0);
6558 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6561 if (!conv || conv->bad_p)
6564 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6565 /*issue_conversion_warnings=*/false,
6568 /* Free all the conversions we allocated. */
6569 obstack_free (&conversion_obstack, p);
6574 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6575 is being bound to a temporary. Create and return a new VAR_DECL
6576 with the indicated TYPE; this variable will store the value to
6577 which the reference is bound. */
6580 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6584 /* Create the variable. */
6585 var = create_temporary_var (type);
6587 /* Register the variable. */
6588 if (TREE_STATIC (decl))
6590 /* Namespace-scope or local static; give it a mangled name. */
6593 TREE_STATIC (var) = 1;
6594 name = mangle_ref_init_variable (decl);
6595 DECL_NAME (var) = name;
6596 SET_DECL_ASSEMBLER_NAME (var, name);
6597 var = pushdecl_top_level (var);
6600 /* Create a new cleanup level if necessary. */
6601 maybe_push_cleanup_level (type);
6606 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6607 initializing a variable of that TYPE. If DECL is non-NULL, it is
6608 the VAR_DECL being initialized with the EXPR. (In that case, the
6609 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6610 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6611 return, if *CLEANUP is no longer NULL, it will be an expression
6612 that should be pushed as a cleanup after the returned expression
6613 is used to initialize DECL.
6615 Return the converted expression. */
6618 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6623 if (type == error_mark_node || error_operand_p (expr))
6624 return error_mark_node;
6626 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6627 p = conversion_obstack_alloc (0);
6629 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
6631 if (!conv || conv->bad_p)
6633 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6634 && !real_lvalue_p (expr))
6635 error ("invalid initialization of non-const reference of "
6636 "type %qT from a temporary of type %qT",
6637 type, TREE_TYPE (expr));
6639 error ("invalid initialization of reference of type "
6640 "%qT from expression of type %qT", type,
6642 return error_mark_node;
6645 /* If DECL is non-NULL, then this special rule applies:
6649 The temporary to which the reference is bound or the temporary
6650 that is the complete object to which the reference is bound
6651 persists for the lifetime of the reference.
6653 The temporaries created during the evaluation of the expression
6654 initializing the reference, except the temporary to which the
6655 reference is bound, are destroyed at the end of the
6656 full-expression in which they are created.
6658 In that case, we store the converted expression into a new
6659 VAR_DECL in a new scope.
6661 However, we want to be careful not to create temporaries when
6662 they are not required. For example, given:
6665 struct D : public B {};
6669 there is no need to copy the return value from "f"; we can just
6670 extend its lifetime. Similarly, given:
6673 struct T { operator S(); };
6677 we can extend the lifetime of the return value of the conversion
6679 gcc_assert (conv->kind == ck_ref_bind);
6683 tree base_conv_type;
6685 /* Skip over the REF_BIND. */
6686 conv = conv->u.next;
6687 /* If the next conversion is a BASE_CONV, skip that too -- but
6688 remember that the conversion was required. */
6689 if (conv->kind == ck_base)
6691 if (conv->check_copy_constructor_p)
6692 check_constructor_callable (TREE_TYPE (expr), expr);
6693 base_conv_type = conv->type;
6694 conv = conv->u.next;
6697 base_conv_type = NULL_TREE;
6698 /* Perform the remainder of the conversion. */
6699 expr = convert_like_real (conv, expr,
6700 /*fn=*/NULL_TREE, /*argnum=*/0,
6702 /*issue_conversion_warnings=*/true,
6703 /*c_cast_p=*/false);
6704 if (error_operand_p (expr))
6705 expr = error_mark_node;
6708 if (!real_lvalue_p (expr))
6713 /* Create the temporary variable. */
6714 type = TREE_TYPE (expr);
6715 var = make_temporary_var_for_ref_to_temp (decl, type);
6716 layout_decl (var, 0);
6717 /* If the rvalue is the result of a function call it will be
6718 a TARGET_EXPR. If it is some other construct (such as a
6719 member access expression where the underlying object is
6720 itself the result of a function call), turn it into a
6721 TARGET_EXPR here. It is important that EXPR be a
6722 TARGET_EXPR below since otherwise the INIT_EXPR will
6723 attempt to make a bitwise copy of EXPR to initialize
6725 if (TREE_CODE (expr) != TARGET_EXPR)
6726 expr = get_target_expr (expr);
6727 /* Create the INIT_EXPR that will initialize the temporary
6729 init = build2 (INIT_EXPR, type, var, expr);
6730 if (at_function_scope_p ())
6732 add_decl_expr (var);
6733 *cleanup = cxx_maybe_build_cleanup (var);
6735 /* We must be careful to destroy the temporary only
6736 after its initialization has taken place. If the
6737 initialization throws an exception, then the
6738 destructor should not be run. We cannot simply
6739 transform INIT into something like:
6741 (INIT, ({ CLEANUP_STMT; }))
6743 because emit_local_var always treats the
6744 initializer as a full-expression. Thus, the
6745 destructor would run too early; it would run at the
6746 end of initializing the reference variable, rather
6747 than at the end of the block enclosing the
6750 The solution is to pass back a cleanup expression
6751 which the caller is responsible for attaching to
6752 the statement tree. */
6756 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6757 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6758 static_aggregates = tree_cons (NULL_TREE, var,
6761 /* Use its address to initialize the reference variable. */
6762 expr = build_address (var);
6764 expr = convert_to_base (expr,
6765 build_pointer_type (base_conv_type),
6766 /*check_access=*/true,
6768 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6771 /* Take the address of EXPR. */
6772 expr = build_unary_op (ADDR_EXPR, expr, 0);
6773 /* If a BASE_CONV was required, perform it now. */
6775 expr = (perform_implicit_conversion
6776 (build_pointer_type (base_conv_type), expr));
6777 expr = build_nop (type, expr);
6781 /* Perform the conversion. */
6782 expr = convert_like (conv, expr);
6784 /* Free all the conversions we allocated. */
6785 obstack_free (&conversion_obstack, p);
6790 #include "gt-cp-call.h"