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 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, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, 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 an 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, int);
173 static conversion *standard_conversion (tree, tree, tree);
174 static conversion *reference_binding (tree, tree, tree, 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 static tree build_temp (tree, tree, int, void (**)(const char *, ...));
198 static void check_constructor_callable (tree, tree);
200 /* Returns nonzero iff the destructor name specified in NAME
201 (a BIT_NOT_EXPR) matches BASETYPE. The operand of NAME can take many
205 check_dtor_name (tree basetype, tree name)
207 name = TREE_OPERAND (name, 0);
209 /* Just accept something we've already complained about. */
210 if (name == error_mark_node)
213 if (TREE_CODE (name) == TYPE_DECL)
214 name = TREE_TYPE (name);
215 else if (TYPE_P (name))
217 else if (TREE_CODE (name) == IDENTIFIER_NODE)
219 if ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
220 || (TREE_CODE (basetype) == ENUMERAL_TYPE
221 && name == TYPE_IDENTIFIER (basetype)))
224 name = get_type_value (name);
230 template <class T> struct S { ~S(); };
234 NAME will be a class template. */
235 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
239 if (name && TYPE_MAIN_VARIANT (basetype) == TYPE_MAIN_VARIANT (name))
244 /* We want the address of a function or method. We avoid creating a
245 pointer-to-member function. */
248 build_addr_func (tree function)
250 tree type = TREE_TYPE (function);
252 /* We have to do these by hand to avoid real pointer to member
254 if (TREE_CODE (type) == METHOD_TYPE)
256 if (TREE_CODE (function) == OFFSET_REF)
258 tree object = build_address (TREE_OPERAND (function, 0));
259 return get_member_function_from_ptrfunc (&object,
260 TREE_OPERAND (function, 1));
262 function = build_address (function);
265 function = decay_conversion (function);
270 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
271 POINTER_TYPE to those. Note, pointer to member function types
272 (TYPE_PTRMEMFUNC_P) must be handled by our callers. */
275 build_call (tree function, tree parms)
277 int is_constructor = 0;
284 function = build_addr_func (function);
286 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
288 sorry ("unable to call pointer to member function here");
289 return error_mark_node;
292 fntype = TREE_TYPE (TREE_TYPE (function));
293 result_type = TREE_TYPE (fntype);
295 if (TREE_CODE (function) == ADDR_EXPR
296 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
297 decl = TREE_OPERAND (function, 0);
301 /* We check both the decl and the type; a function may be known not to
302 throw without being declared throw(). */
303 nothrow = ((decl && TREE_NOTHROW (decl))
304 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
306 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
307 current_function_returns_abnormally = 1;
309 if (decl && TREE_DEPRECATED (decl))
310 warn_deprecated_use (decl);
311 require_complete_eh_spec_types (fntype, decl);
313 if (decl && DECL_CONSTRUCTOR_P (decl))
316 if (decl && ! TREE_USED (decl))
318 /* We invoke build_call directly for several library functions.
319 These may have been declared normally if we're building libgcc,
320 so we can't just check DECL_ARTIFICIAL. */
321 gcc_assert (DECL_ARTIFICIAL (decl)
322 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
327 /* Don't pass empty class objects by value. This is useful
328 for tags in STL, which are used to control overload resolution.
329 We don't need to handle other cases of copying empty classes. */
330 if (! decl || ! DECL_BUILT_IN (decl))
331 for (tmp = parms; tmp; tmp = TREE_CHAIN (tmp))
332 if (is_empty_class (TREE_TYPE (TREE_VALUE (tmp)))
333 && ! TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (tmp))))
335 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (TREE_VALUE (tmp)));
336 TREE_VALUE (tmp) = build2 (COMPOUND_EXPR, TREE_TYPE (t),
337 TREE_VALUE (tmp), t);
340 function = build3 (CALL_EXPR, result_type, function, parms, NULL_TREE);
341 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
342 TREE_NOTHROW (function) = nothrow;
347 /* Build something of the form ptr->method (args)
348 or object.method (args). This can also build
349 calls to constructors, and find friends.
351 Member functions always take their class variable
354 INSTANCE is a class instance.
356 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
358 PARMS help to figure out what that NAME really refers to.
360 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
361 down to the real instance type to use for access checking. We need this
362 information to get protected accesses correct.
364 FLAGS is the logical disjunction of zero or more LOOKUP_
365 flags. See cp-tree.h for more info.
367 If this is all OK, calls build_function_call with the resolved
370 This function must also handle being called to perform
371 initialization, promotion/coercion of arguments, and
372 instantiation of default parameters.
374 Note that NAME may refer to an instance variable name. If
375 `operator()()' is defined for the type of that field, then we return
378 /* New overloading code. */
380 typedef struct z_candidate z_candidate;
382 typedef struct candidate_warning candidate_warning;
383 struct candidate_warning {
385 candidate_warning *next;
389 /* The FUNCTION_DECL that will be called if this candidate is
390 selected by overload resolution. */
392 /* The arguments to use when calling this function. */
394 /* The implicit conversion sequences for each of the arguments to
397 /* The number of implicit conversion sequences. */
399 /* If FN is a user-defined conversion, the standard conversion
400 sequence from the type returned by FN to the desired destination
402 conversion *second_conv;
404 /* If FN is a member function, the binfo indicating the path used to
405 qualify the name of FN at the call site. This path is used to
406 determine whether or not FN is accessible if it is selected by
407 overload resolution. The DECL_CONTEXT of FN will always be a
408 (possibly improper) base of this binfo. */
410 /* If FN is a non-static member function, the binfo indicating the
411 subobject to which the `this' pointer should be converted if FN
412 is selected by overload resolution. The type pointed to the by
413 the `this' pointer must correspond to the most derived class
414 indicated by the CONVERSION_PATH. */
415 tree conversion_path;
417 candidate_warning *warnings;
421 /* Returns true iff T is a null pointer constant in the sense of
425 null_ptr_cst_p (tree t)
429 A null pointer constant is an integral constant expression
430 (_expr.const_) rvalue of integer type that evaluates to zero. */
431 if (DECL_INTEGRAL_CONSTANT_VAR_P (t))
432 t = decl_constant_value (t);
434 || (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t)))
439 /* Returns nonzero if PARMLIST consists of only default parms and/or
443 sufficient_parms_p (tree parmlist)
445 for (; parmlist && parmlist != void_list_node;
446 parmlist = TREE_CHAIN (parmlist))
447 if (!TREE_PURPOSE (parmlist))
452 /* Allocate N bytes of memory from the conversion obstack. The memory
453 is zeroed before being returned. */
456 conversion_obstack_alloc (size_t n)
459 if (!conversion_obstack_initialized)
461 gcc_obstack_init (&conversion_obstack);
462 conversion_obstack_initialized = true;
464 p = obstack_alloc (&conversion_obstack, n);
469 /* Dynamically allocate a conversion. */
472 alloc_conversion (conversion_kind kind)
475 c = conversion_obstack_alloc (sizeof (conversion));
480 #ifdef ENABLE_CHECKING
482 /* Make sure that all memory on the conversion obstack has been
486 validate_conversion_obstack (void)
488 if (conversion_obstack_initialized)
489 gcc_assert ((obstack_next_free (&conversion_obstack)
490 == obstack_base (&conversion_obstack)));
493 #endif /* ENABLE_CHECKING */
495 /* Dynamically allocate an array of N conversions. */
498 alloc_conversions (size_t n)
500 return conversion_obstack_alloc (n * sizeof (conversion *));
504 build_conv (conversion_kind code, tree type, conversion *from)
507 conversion_rank rank = CONVERSION_RANK (from);
509 /* We can't use buildl1 here because CODE could be USER_CONV, which
510 takes two arguments. In that case, the caller is responsible for
511 filling in the second argument. */
512 t = alloc_conversion (code);
535 t->user_conv_p = (code == ck_user || from->user_conv_p);
536 t->bad_p = from->bad_p;
541 /* Build a representation of the identity conversion from EXPR to
542 itself. The TYPE should match the the type of EXPR, if EXPR is
546 build_identity_conv (tree type, tree expr)
550 c = alloc_conversion (ck_identity);
557 /* Converting from EXPR to TYPE was ambiguous in the sense that there
558 were multiple user-defined conversions to accomplish the job.
559 Build a conversion that indicates that ambiguity. */
562 build_ambiguous_conv (tree type, tree expr)
566 c = alloc_conversion (ck_ambig);
574 strip_top_quals (tree t)
576 if (TREE_CODE (t) == ARRAY_TYPE)
578 return cp_build_qualified_type (t, 0);
581 /* Returns the standard conversion path (see [conv]) from type FROM to type
582 TO, if any. For proper handling of null pointer constants, you must
583 also pass the expression EXPR to convert from. */
586 standard_conversion (tree to, tree from, tree expr)
588 enum tree_code fcode, tcode;
590 bool fromref = false;
592 to = non_reference (to);
593 if (TREE_CODE (from) == REFERENCE_TYPE)
596 from = TREE_TYPE (from);
598 to = strip_top_quals (to);
599 from = strip_top_quals (from);
601 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
602 && expr && type_unknown_p (expr))
604 expr = instantiate_type (to, expr, tf_conv);
605 if (expr == error_mark_node)
607 from = TREE_TYPE (expr);
610 fcode = TREE_CODE (from);
611 tcode = TREE_CODE (to);
613 conv = build_identity_conv (from, expr);
614 if (fcode == FUNCTION_TYPE)
616 from = build_pointer_type (from);
617 fcode = TREE_CODE (from);
618 conv = build_conv (ck_lvalue, from, conv);
620 else if (fcode == ARRAY_TYPE)
622 from = build_pointer_type (TREE_TYPE (from));
623 fcode = TREE_CODE (from);
624 conv = build_conv (ck_lvalue, from, conv);
626 else if (fromref || (expr && lvalue_p (expr)))
627 conv = build_conv (ck_rvalue, from, conv);
629 /* Allow conversion between `__complex__' data types. */
630 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
632 /* The standard conversion sequence to convert FROM to TO is
633 the standard conversion sequence to perform componentwise
635 conversion *part_conv = standard_conversion
636 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE);
640 conv = build_conv (part_conv->kind, to, conv);
641 conv->rank = part_conv->rank;
649 if (same_type_p (from, to))
652 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
653 && expr && null_ptr_cst_p (expr))
654 conv = build_conv (ck_std, to, conv);
655 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
656 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
658 /* For backwards brain damage compatibility, allow interconversion of
659 pointers and integers with a pedwarn. */
660 conv = build_conv (ck_std, to, conv);
663 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
665 /* For backwards brain damage compatibility, allow interconversion of
666 enums and integers with a pedwarn. */
667 conv = build_conv (ck_std, to, conv);
670 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
671 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
676 if (tcode == POINTER_TYPE
677 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
680 else if (VOID_TYPE_P (TREE_TYPE (to))
681 && !TYPE_PTRMEM_P (from)
682 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
684 from = build_pointer_type
685 (cp_build_qualified_type (void_type_node,
686 cp_type_quals (TREE_TYPE (from))));
687 conv = build_conv (ck_ptr, from, conv);
689 else if (TYPE_PTRMEM_P (from))
691 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
692 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
694 if (DERIVED_FROM_P (fbase, tbase)
695 && (same_type_ignoring_top_level_qualifiers_p
696 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
697 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
699 from = build_ptrmem_type (tbase,
700 TYPE_PTRMEM_POINTED_TO_TYPE (from));
701 conv = build_conv (ck_pmem, from, conv);
703 else if (!same_type_p (fbase, tbase))
706 else if (IS_AGGR_TYPE (TREE_TYPE (from))
707 && IS_AGGR_TYPE (TREE_TYPE (to))
710 An rvalue of type "pointer to cv D," where D is a
711 class type, can be converted to an rvalue of type
712 "pointer to cv B," where B is a base class (clause
713 _class.derived_) of D. If B is an inaccessible
714 (clause _class.access_) or ambiguous
715 (_class.member.lookup_) base class of D, a program
716 that necessitates this conversion is ill-formed.
717 Therefore, we use DERIVED_FROM_P, and do not check
718 access or uniqueness. */
719 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
722 cp_build_qualified_type (TREE_TYPE (to),
723 cp_type_quals (TREE_TYPE (from)));
724 from = build_pointer_type (from);
725 conv = build_conv (ck_ptr, from, conv);
729 if (tcode == POINTER_TYPE)
731 to_pointee = TREE_TYPE (to);
732 from_pointee = TREE_TYPE (from);
736 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
737 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
740 if (same_type_p (from, to))
742 else if (comp_ptr_ttypes (to_pointee, from_pointee))
743 conv = build_conv (ck_qual, to, conv);
744 else if (expr && string_conv_p (to, expr, 0))
745 /* converting from string constant to char *. */
746 conv = build_conv (ck_qual, to, conv);
747 else if (ptr_reasonably_similar (to_pointee, from_pointee))
749 conv = build_conv (ck_ptr, to, conv);
757 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
759 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
760 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
761 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
762 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
764 if (!DERIVED_FROM_P (fbase, tbase)
765 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
766 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
767 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
768 || cp_type_quals (fbase) != cp_type_quals (tbase))
771 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
772 from = build_method_type_directly (from,
774 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
775 from = build_ptrmemfunc_type (build_pointer_type (from));
776 conv = build_conv (ck_pmem, from, conv);
779 else if (tcode == BOOLEAN_TYPE)
783 An rvalue of arithmetic, enumeration, pointer, or pointer to
784 member type can be converted to an rvalue of type bool. */
785 if (ARITHMETIC_TYPE_P (from)
786 || fcode == ENUMERAL_TYPE
787 || fcode == POINTER_TYPE
788 || TYPE_PTR_TO_MEMBER_P (from))
790 conv = build_conv (ck_std, to, conv);
791 if (fcode == POINTER_TYPE
792 || TYPE_PTRMEM_P (from)
793 || (TYPE_PTRMEMFUNC_P (from)
794 && conv->rank < cr_pbool))
795 conv->rank = cr_pbool;
801 /* We don't check for ENUMERAL_TYPE here because there are no standard
802 conversions to enum type. */
803 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
804 || tcode == REAL_TYPE)
806 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
808 conv = build_conv (ck_std, to, conv);
810 /* Give this a better rank if it's a promotion. */
811 if (same_type_p (to, type_promotes_to (from))
812 && conv->u.next->rank <= cr_promotion)
813 conv->rank = cr_promotion;
815 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
816 && vector_types_convertible_p (from, to))
817 return build_conv (ck_std, to, conv);
818 else if (IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
819 && is_properly_derived_from (from, to))
821 if (conv->kind == ck_rvalue)
823 conv = build_conv (ck_base, to, conv);
824 /* The derived-to-base conversion indicates the initialization
825 of a parameter with base type from an object of a derived
826 type. A temporary object is created to hold the result of
828 conv->need_temporary_p = true;
836 /* Returns nonzero if T1 is reference-related to T2. */
839 reference_related_p (tree t1, tree t2)
841 t1 = TYPE_MAIN_VARIANT (t1);
842 t2 = TYPE_MAIN_VARIANT (t2);
846 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
847 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
849 return (same_type_p (t1, t2)
850 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
851 && DERIVED_FROM_P (t1, t2)));
854 /* Returns nonzero if T1 is reference-compatible with T2. */
857 reference_compatible_p (tree t1, tree t2)
861 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
862 reference-related to T2 and cv1 is the same cv-qualification as,
863 or greater cv-qualification than, cv2. */
864 return (reference_related_p (t1, t2)
865 && at_least_as_qualified_p (t1, t2));
868 /* Determine whether or not the EXPR (of class type S) can be
869 converted to T as in [over.match.ref]. */
872 convert_class_to_reference (tree t, tree s, tree expr)
878 struct z_candidate *candidates;
879 struct z_candidate *cand;
882 conversions = lookup_conversions (s);
888 Assuming that "cv1 T" is the underlying type of the reference
889 being initialized, and "cv S" is the type of the initializer
890 expression, with S a class type, the candidate functions are
893 --The conversion functions of S and its base classes are
894 considered. Those that are not hidden within S and yield type
895 "reference to cv2 T2", where "cv1 T" is reference-compatible
896 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
898 The argument list has one argument, which is the initializer
903 /* Conceptually, we should take the address of EXPR and put it in
904 the argument list. Unfortunately, however, that can result in
905 error messages, which we should not issue now because we are just
906 trying to find a conversion operator. Therefore, we use NULL,
907 cast to the appropriate type. */
908 arglist = build_int_cst (build_pointer_type (s), 0);
909 arglist = build_tree_list (NULL_TREE, arglist);
911 reference_type = build_reference_type (t);
915 tree fns = TREE_VALUE (conversions);
917 for (; fns; fns = OVL_NEXT (fns))
919 tree f = OVL_CURRENT (fns);
920 tree t2 = TREE_TYPE (TREE_TYPE (f));
924 /* If this is a template function, try to get an exact
926 if (TREE_CODE (f) == TEMPLATE_DECL)
928 cand = add_template_candidate (&candidates,
934 TREE_PURPOSE (conversions),
940 /* Now, see if the conversion function really returns
941 an lvalue of the appropriate type. From the
942 point of view of unification, simply returning an
943 rvalue of the right type is good enough. */
945 t2 = TREE_TYPE (TREE_TYPE (f));
946 if (TREE_CODE (t2) != REFERENCE_TYPE
947 || !reference_compatible_p (t, TREE_TYPE (t2)))
949 candidates = candidates->next;
954 else if (TREE_CODE (t2) == REFERENCE_TYPE
955 && reference_compatible_p (t, TREE_TYPE (t2)))
956 cand = add_function_candidate (&candidates, f, s, arglist,
958 TREE_PURPOSE (conversions),
963 conversion *identity_conv;
964 /* Build a standard conversion sequence indicating the
965 binding from the reference type returned by the
966 function to the desired REFERENCE_TYPE. */
968 = build_identity_conv (TREE_TYPE (TREE_TYPE
969 (TREE_TYPE (cand->fn))),
972 = (direct_reference_binding
973 (reference_type, identity_conv));
974 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
977 conversions = TREE_CHAIN (conversions);
980 candidates = splice_viable (candidates, pedantic, &any_viable_p);
981 /* If none of the conversion functions worked out, let our caller
986 cand = tourney (candidates);
990 /* Now that we know that this is the function we're going to use fix
991 the dummy first argument. */
992 cand->args = tree_cons (NULL_TREE,
994 TREE_CHAIN (cand->args));
996 /* Build a user-defined conversion sequence representing the
998 conv = build_conv (ck_user,
999 TREE_TYPE (TREE_TYPE (cand->fn)),
1000 build_identity_conv (TREE_TYPE (expr), expr));
1003 /* Merge it with the standard conversion sequence from the
1004 conversion function's return type to the desired type. */
1005 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1007 if (cand->viable == -1)
1010 return cand->second_conv;
1013 /* A reference of the indicated TYPE is being bound directly to the
1014 expression represented by the implicit conversion sequence CONV.
1015 Return a conversion sequence for this binding. */
1018 direct_reference_binding (tree type, conversion *conv)
1022 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1023 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1025 t = TREE_TYPE (type);
1029 When a parameter of reference type binds directly
1030 (_dcl.init.ref_) to an argument expression, the implicit
1031 conversion sequence is the identity conversion, unless the
1032 argument expression has a type that is a derived class of the
1033 parameter type, in which case the implicit conversion sequence is
1034 a derived-to-base Conversion.
1036 If the parameter binds directly to the result of applying a
1037 conversion function to the argument expression, the implicit
1038 conversion sequence is a user-defined conversion sequence
1039 (_over.ics.user_), with the second standard conversion sequence
1040 either an identity conversion or, if the conversion function
1041 returns an entity of a type that is a derived class of the
1042 parameter type, a derived-to-base conversion. */
1043 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1045 /* Represent the derived-to-base conversion. */
1046 conv = build_conv (ck_base, t, conv);
1047 /* We will actually be binding to the base-class subobject in
1048 the derived class, so we mark this conversion appropriately.
1049 That way, convert_like knows not to generate a temporary. */
1050 conv->need_temporary_p = false;
1052 return build_conv (ck_ref_bind, type, conv);
1055 /* Returns the conversion path from type FROM to reference type TO for
1056 purposes of reference binding. For lvalue binding, either pass a
1057 reference type to FROM or an lvalue expression to EXPR. If the
1058 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1059 the conversion returned. */
1062 reference_binding (tree rto, tree rfrom, tree expr, int flags)
1064 conversion *conv = NULL;
1065 tree to = TREE_TYPE (rto);
1069 cp_lvalue_kind lvalue_p = clk_none;
1071 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1073 expr = instantiate_type (to, expr, tf_none);
1074 if (expr == error_mark_node)
1076 from = TREE_TYPE (expr);
1079 if (TREE_CODE (from) == REFERENCE_TYPE)
1081 /* Anything with reference type is an lvalue. */
1082 lvalue_p = clk_ordinary;
1083 from = TREE_TYPE (from);
1086 lvalue_p = real_lvalue_p (expr);
1088 /* Figure out whether or not the types are reference-related and
1089 reference compatible. We have do do this after stripping
1090 references from FROM. */
1091 related_p = reference_related_p (to, from);
1092 compatible_p = reference_compatible_p (to, from);
1094 if (lvalue_p && compatible_p)
1098 If the initializer expression
1100 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1101 is reference-compatible with "cv2 T2,"
1103 the reference is bound directly to the initializer expression
1105 conv = build_identity_conv (from, expr);
1106 conv = direct_reference_binding (rto, conv);
1107 if ((lvalue_p & clk_bitfield) != 0
1108 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1109 /* For the purposes of overload resolution, we ignore the fact
1110 this expression is a bitfield or packed field. (In particular,
1111 [over.ics.ref] says specifically that a function with a
1112 non-const reference parameter is viable even if the
1113 argument is a bitfield.)
1115 However, when we actually call the function we must create
1116 a temporary to which to bind the reference. If the
1117 reference is volatile, or isn't const, then we cannot make
1118 a temporary, so we just issue an error when the conversion
1120 conv->need_temporary_p = true;
1124 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1128 If the initializer expression
1130 -- has a class type (i.e., T2 is a class type) can be
1131 implicitly converted to an lvalue of type "cv3 T3," where
1132 "cv1 T1" is reference-compatible with "cv3 T3". (this
1133 conversion is selected by enumerating the applicable
1134 conversion functions (_over.match.ref_) and choosing the
1135 best one through overload resolution. (_over.match_).
1137 the reference is bound to the lvalue result of the conversion
1138 in the second case. */
1139 conv = convert_class_to_reference (to, from, expr);
1144 /* From this point on, we conceptually need temporaries, even if we
1145 elide them. Only the cases above are "direct bindings". */
1146 if (flags & LOOKUP_NO_TEMP_BIND)
1151 When a parameter of reference type is not bound directly to an
1152 argument expression, the conversion sequence is the one required
1153 to convert the argument expression to the underlying type of the
1154 reference according to _over.best.ics_. Conceptually, this
1155 conversion sequence corresponds to copy-initializing a temporary
1156 of the underlying type with the argument expression. Any
1157 difference in top-level cv-qualification is subsumed by the
1158 initialization itself and does not constitute a conversion. */
1162 Otherwise, the reference shall be to a non-volatile const type. */
1163 if (!CP_TYPE_CONST_NON_VOLATILE_P (to))
1168 If the initializer expression is an rvalue, with T2 a class type,
1169 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1170 is bound in one of the following ways:
1172 -- The reference is bound to the object represented by the rvalue
1173 or to a sub-object within that object.
1177 We use the first alternative. The implicit conversion sequence
1178 is supposed to be same as we would obtain by generating a
1179 temporary. Fortunately, if the types are reference compatible,
1180 then this is either an identity conversion or the derived-to-base
1181 conversion, just as for direct binding. */
1182 if (CLASS_TYPE_P (from) && compatible_p)
1184 conv = build_identity_conv (from, expr);
1185 conv = direct_reference_binding (rto, conv);
1186 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1187 conv->u.next->check_copy_constructor_p = true;
1193 Otherwise, a temporary of type "cv1 T1" is created and
1194 initialized from the initializer expression using the rules for a
1195 non-reference copy initialization. If T1 is reference-related to
1196 T2, cv1 must be the same cv-qualification as, or greater
1197 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1198 if (related_p && !at_least_as_qualified_p (to, from))
1201 conv = implicit_conversion (to, from, expr, flags);
1205 conv = build_conv (ck_ref_bind, rto, conv);
1206 /* This reference binding, unlike those above, requires the
1207 creation of a temporary. */
1208 conv->need_temporary_p = true;
1213 /* Returns the implicit conversion sequence (see [over.ics]) from type FROM
1214 to type TO. The optional expression EXPR may affect the conversion.
1215 FLAGS are the usual overloading flags. Only LOOKUP_NO_CONVERSION is
1219 implicit_conversion (tree to, tree from, tree expr, int flags)
1223 if (from == error_mark_node || to == error_mark_node
1224 || expr == error_mark_node)
1227 if (TREE_CODE (to) == REFERENCE_TYPE)
1228 conv = reference_binding (to, from, expr, flags);
1230 conv = standard_conversion (to, from, expr);
1235 if (expr != NULL_TREE
1236 && (IS_AGGR_TYPE (from)
1237 || IS_AGGR_TYPE (to))
1238 && (flags & LOOKUP_NO_CONVERSION) == 0)
1240 struct z_candidate *cand;
1242 cand = build_user_type_conversion_1
1243 (to, expr, LOOKUP_ONLYCONVERTING);
1245 conv = cand->second_conv;
1247 /* We used to try to bind a reference to a temporary here, but that
1248 is now handled by the recursive call to this function at the end
1249 of reference_binding. */
1256 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1259 static struct z_candidate *
1260 add_candidate (struct z_candidate **candidates,
1262 size_t num_convs, conversion **convs,
1263 tree access_path, tree conversion_path,
1266 struct z_candidate *cand
1267 = conversion_obstack_alloc (sizeof (struct z_candidate));
1271 cand->convs = convs;
1272 cand->num_convs = num_convs;
1273 cand->access_path = access_path;
1274 cand->conversion_path = conversion_path;
1275 cand->viable = viable;
1276 cand->next = *candidates;
1282 /* Create an overload candidate for the function or method FN called with
1283 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1284 to implicit_conversion.
1286 CTYPE, if non-NULL, is the type we want to pretend this function
1287 comes from for purposes of overload resolution. */
1289 static struct z_candidate *
1290 add_function_candidate (struct z_candidate **candidates,
1291 tree fn, tree ctype, tree arglist,
1292 tree access_path, tree conversion_path,
1295 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1298 tree parmnode, argnode;
1302 /* Built-in functions that haven't been declared don't really
1304 if (DECL_ANTICIPATED (fn))
1307 /* The `this', `in_chrg' and VTT arguments to constructors are not
1308 considered in overload resolution. */
1309 if (DECL_CONSTRUCTOR_P (fn))
1311 parmlist = skip_artificial_parms_for (fn, parmlist);
1312 orig_arglist = arglist;
1313 arglist = skip_artificial_parms_for (fn, arglist);
1316 orig_arglist = arglist;
1318 len = list_length (arglist);
1319 convs = alloc_conversions (len);
1321 /* 13.3.2 - Viable functions [over.match.viable]
1322 First, to be a viable function, a candidate function shall have enough
1323 parameters to agree in number with the arguments in the list.
1325 We need to check this first; otherwise, checking the ICSes might cause
1326 us to produce an ill-formed template instantiation. */
1328 parmnode = parmlist;
1329 for (i = 0; i < len; ++i)
1331 if (parmnode == NULL_TREE || parmnode == void_list_node)
1333 parmnode = TREE_CHAIN (parmnode);
1336 if (i < len && parmnode)
1339 /* Make sure there are default args for the rest of the parms. */
1340 else if (!sufficient_parms_p (parmnode))
1346 /* Second, for F to be a viable function, there shall exist for each
1347 argument an implicit conversion sequence that converts that argument
1348 to the corresponding parameter of F. */
1350 parmnode = parmlist;
1353 for (i = 0; i < len; ++i)
1355 tree arg = TREE_VALUE (argnode);
1356 tree argtype = lvalue_type (arg);
1360 if (parmnode == void_list_node)
1363 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1364 && ! DECL_CONSTRUCTOR_P (fn));
1368 tree parmtype = TREE_VALUE (parmnode);
1370 /* The type of the implicit object parameter ('this') for
1371 overload resolution is not always the same as for the
1372 function itself; conversion functions are considered to
1373 be members of the class being converted, and functions
1374 introduced by a using-declaration are considered to be
1375 members of the class that uses them.
1377 Since build_over_call ignores the ICS for the `this'
1378 parameter, we can just change the parm type. */
1379 if (ctype && is_this)
1382 = build_qualified_type (ctype,
1383 TYPE_QUALS (TREE_TYPE (parmtype)));
1384 parmtype = build_pointer_type (parmtype);
1387 t = implicit_conversion (parmtype, argtype, arg, flags);
1391 t = build_identity_conv (argtype, arg);
1392 t->ellipsis_p = true;
1409 parmnode = TREE_CHAIN (parmnode);
1410 argnode = TREE_CHAIN (argnode);
1414 return add_candidate (candidates, fn, orig_arglist, len, convs,
1415 access_path, conversion_path, viable);
1418 /* Create an overload candidate for the conversion function FN which will
1419 be invoked for expression OBJ, producing a pointer-to-function which
1420 will in turn be called with the argument list ARGLIST, and add it to
1421 CANDIDATES. FLAGS is passed on to implicit_conversion.
1423 Actually, we don't really care about FN; we care about the type it
1424 converts to. There may be multiple conversion functions that will
1425 convert to that type, and we rely on build_user_type_conversion_1 to
1426 choose the best one; so when we create our candidate, we record the type
1427 instead of the function. */
1429 static struct z_candidate *
1430 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1431 tree arglist, tree access_path, tree conversion_path)
1433 tree totype = TREE_TYPE (TREE_TYPE (fn));
1434 int i, len, viable, flags;
1435 tree parmlist, parmnode, argnode;
1438 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1439 parmlist = TREE_TYPE (parmlist);
1440 parmlist = TYPE_ARG_TYPES (parmlist);
1442 len = list_length (arglist) + 1;
1443 convs = alloc_conversions (len);
1444 parmnode = parmlist;
1447 flags = LOOKUP_NORMAL;
1449 /* Don't bother looking up the same type twice. */
1450 if (*candidates && (*candidates)->fn == totype)
1453 for (i = 0; i < len; ++i)
1455 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1456 tree argtype = lvalue_type (arg);
1460 t = implicit_conversion (totype, argtype, arg, flags);
1461 else if (parmnode == void_list_node)
1464 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, flags);
1467 t = build_identity_conv (argtype, arg);
1468 t->ellipsis_p = true;
1482 parmnode = TREE_CHAIN (parmnode);
1483 argnode = TREE_CHAIN (argnode);
1489 if (!sufficient_parms_p (parmnode))
1492 return add_candidate (candidates, totype, arglist, len, convs,
1493 access_path, conversion_path, viable);
1497 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1498 tree type1, tree type2, tree *args, tree *argtypes,
1510 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1511 convs = alloc_conversions (num_convs);
1513 for (i = 0; i < 2; ++i)
1518 t = implicit_conversion (types[i], argtypes[i], args[i], flags);
1522 /* We need something for printing the candidate. */
1523 t = build_identity_conv (types[i], NULL_TREE);
1530 /* For COND_EXPR we rearranged the arguments; undo that now. */
1533 convs[2] = convs[1];
1534 convs[1] = convs[0];
1535 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], flags);
1542 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1544 /*access_path=*/NULL_TREE,
1545 /*conversion_path=*/NULL_TREE,
1550 is_complete (tree t)
1552 return COMPLETE_TYPE_P (complete_type (t));
1555 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1558 promoted_arithmetic_type_p (tree type)
1562 In this section, the term promoted integral type is used to refer
1563 to those integral types which are preserved by integral promotion
1564 (including e.g. int and long but excluding e.g. char).
1565 Similarly, the term promoted arithmetic type refers to promoted
1566 integral types plus floating types. */
1567 return ((INTEGRAL_TYPE_P (type)
1568 && same_type_p (type_promotes_to (type), type))
1569 || TREE_CODE (type) == REAL_TYPE);
1572 /* Create any builtin operator overload candidates for the operator in
1573 question given the converted operand types TYPE1 and TYPE2. The other
1574 args are passed through from add_builtin_candidates to
1575 build_builtin_candidate.
1577 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1578 If CODE is requires candidates operands of the same type of the kind
1579 of which TYPE1 and TYPE2 are, we add both candidates
1580 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1583 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1584 enum tree_code code2, tree fnname, tree type1,
1585 tree type2, tree *args, tree *argtypes, int flags)
1589 case POSTINCREMENT_EXPR:
1590 case POSTDECREMENT_EXPR:
1591 args[1] = integer_zero_node;
1592 type2 = integer_type_node;
1601 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1602 and VQ is either volatile or empty, there exist candidate operator
1603 functions of the form
1604 VQ T& operator++(VQ T&);
1605 T operator++(VQ T&, int);
1606 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1607 type other than bool, and VQ is either volatile or empty, there exist
1608 candidate operator functions of the form
1609 VQ T& operator--(VQ T&);
1610 T operator--(VQ T&, int);
1611 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1612 complete object type, and VQ is either volatile or empty, there exist
1613 candidate operator functions of the form
1614 T*VQ& operator++(T*VQ&);
1615 T*VQ& operator--(T*VQ&);
1616 T* operator++(T*VQ&, int);
1617 T* operator--(T*VQ&, int); */
1619 case POSTDECREMENT_EXPR:
1620 case PREDECREMENT_EXPR:
1621 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1623 case POSTINCREMENT_EXPR:
1624 case PREINCREMENT_EXPR:
1625 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1627 type1 = build_reference_type (type1);
1632 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1633 exist candidate operator functions of the form
1637 8 For every function type T, there exist candidate operator functions of
1639 T& operator*(T*); */
1642 if (TREE_CODE (type1) == POINTER_TYPE
1643 && (TYPE_PTROB_P (type1)
1644 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1648 /* 9 For every type T, there exist candidate operator functions of the form
1651 10For every promoted arithmetic type T, there exist candidate operator
1652 functions of the form
1656 case CONVERT_EXPR: /* unary + */
1657 if (TREE_CODE (type1) == POINTER_TYPE)
1660 if (ARITHMETIC_TYPE_P (type1))
1664 /* 11For every promoted integral type T, there exist candidate operator
1665 functions of the form
1669 if (INTEGRAL_TYPE_P (type1))
1673 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1674 is the same type as C2 or is a derived class of C2, T is a complete
1675 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1676 there exist candidate operator functions of the form
1677 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1678 where CV12 is the union of CV1 and CV2. */
1681 if (TREE_CODE (type1) == POINTER_TYPE
1682 && TYPE_PTR_TO_MEMBER_P (type2))
1684 tree c1 = TREE_TYPE (type1);
1685 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1687 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1688 && (TYPE_PTRMEMFUNC_P (type2)
1689 || is_complete (TREE_TYPE (TREE_TYPE (type2)))))
1694 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1695 didate operator functions of the form
1700 bool operator<(L, R);
1701 bool operator>(L, R);
1702 bool operator<=(L, R);
1703 bool operator>=(L, R);
1704 bool operator==(L, R);
1705 bool operator!=(L, R);
1706 where LR is the result of the usual arithmetic conversions between
1709 14For every pair of types T and I, where T is a cv-qualified or cv-
1710 unqualified complete object type and I is a promoted integral type,
1711 there exist candidate operator functions of the form
1712 T* operator+(T*, I);
1713 T& operator[](T*, I);
1714 T* operator-(T*, I);
1715 T* operator+(I, T*);
1716 T& operator[](I, T*);
1718 15For every T, where T is a pointer to complete object type, there exist
1719 candidate operator functions of the form112)
1720 ptrdiff_t operator-(T, T);
1722 16For every pointer or enumeration type T, there exist candidate operator
1723 functions of the form
1724 bool operator<(T, T);
1725 bool operator>(T, T);
1726 bool operator<=(T, T);
1727 bool operator>=(T, T);
1728 bool operator==(T, T);
1729 bool operator!=(T, T);
1731 17For every pointer to member type T, there exist candidate operator
1732 functions of the form
1733 bool operator==(T, T);
1734 bool operator!=(T, T); */
1737 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1739 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1741 type2 = ptrdiff_type_node;
1745 case TRUNC_DIV_EXPR:
1746 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1752 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1753 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1755 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1760 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1772 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1774 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1776 if (TREE_CODE (type1) == ENUMERAL_TYPE && TREE_CODE (type2) == ENUMERAL_TYPE)
1778 if (TYPE_PTR_P (type1) && null_ptr_cst_p (args[1]))
1783 if (null_ptr_cst_p (args[0]) && TYPE_PTR_P (type2))
1791 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1794 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1796 type1 = ptrdiff_type_node;
1799 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1801 type2 = ptrdiff_type_node;
1806 /* 18For every pair of promoted integral types L and R, there exist candi-
1807 date operator functions of the form
1814 where LR is the result of the usual arithmetic conversions between
1817 case TRUNC_MOD_EXPR:
1823 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1827 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1828 type, VQ is either volatile or empty, and R is a promoted arithmetic
1829 type, there exist candidate operator functions of the form
1830 VQ L& operator=(VQ L&, R);
1831 VQ L& operator*=(VQ L&, R);
1832 VQ L& operator/=(VQ L&, R);
1833 VQ L& operator+=(VQ L&, R);
1834 VQ L& operator-=(VQ L&, R);
1836 20For every pair T, VQ), where T is any type and VQ is either volatile
1837 or empty, there exist candidate operator functions of the form
1838 T*VQ& operator=(T*VQ&, T*);
1840 21For every pair T, VQ), where T is a pointer to member type and VQ is
1841 either volatile or empty, there exist candidate operator functions of
1843 VQ T& operator=(VQ T&, T);
1845 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1846 unqualified complete object type, VQ is either volatile or empty, and
1847 I is a promoted integral type, there exist candidate operator func-
1849 T*VQ& operator+=(T*VQ&, I);
1850 T*VQ& operator-=(T*VQ&, I);
1852 23For every triple L, VQ, R), where L is an integral or enumeration
1853 type, VQ is either volatile or empty, and R is a promoted integral
1854 type, there exist candidate operator functions of the form
1856 VQ L& operator%=(VQ L&, R);
1857 VQ L& operator<<=(VQ L&, R);
1858 VQ L& operator>>=(VQ L&, R);
1859 VQ L& operator&=(VQ L&, R);
1860 VQ L& operator^=(VQ L&, R);
1861 VQ L& operator|=(VQ L&, R); */
1868 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1870 type2 = ptrdiff_type_node;
1874 case TRUNC_DIV_EXPR:
1875 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1879 case TRUNC_MOD_EXPR:
1885 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1890 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1892 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1893 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1894 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1895 || ((TYPE_PTRMEMFUNC_P (type1)
1896 || TREE_CODE (type1) == POINTER_TYPE)
1897 && null_ptr_cst_p (args[1])))
1907 type1 = build_reference_type (type1);
1913 For every pair of promoted arithmetic types L and R, there
1914 exist candidate operator functions of the form
1916 LR operator?(bool, L, R);
1918 where LR is the result of the usual arithmetic conversions
1919 between types L and R.
1921 For every type T, where T is a pointer or pointer-to-member
1922 type, there exist candidate operator functions of the form T
1923 operator?(bool, T, T); */
1925 if (promoted_arithmetic_type_p (type1)
1926 && promoted_arithmetic_type_p (type2))
1930 /* Otherwise, the types should be pointers. */
1931 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
1932 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
1935 /* We don't check that the two types are the same; the logic
1936 below will actually create two candidates; one in which both
1937 parameter types are TYPE1, and one in which both parameter
1945 /* If we're dealing with two pointer types or two enumeral types,
1946 we need candidates for both of them. */
1947 if (type2 && !same_type_p (type1, type2)
1948 && TREE_CODE (type1) == TREE_CODE (type2)
1949 && (TREE_CODE (type1) == REFERENCE_TYPE
1950 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1951 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1952 || TYPE_PTRMEMFUNC_P (type1)
1953 || IS_AGGR_TYPE (type1)
1954 || TREE_CODE (type1) == ENUMERAL_TYPE))
1956 build_builtin_candidate
1957 (candidates, fnname, type1, type1, args, argtypes, flags);
1958 build_builtin_candidate
1959 (candidates, fnname, type2, type2, args, argtypes, flags);
1963 build_builtin_candidate
1964 (candidates, fnname, type1, type2, args, argtypes, flags);
1968 type_decays_to (tree type)
1970 if (TREE_CODE (type) == ARRAY_TYPE)
1971 return build_pointer_type (TREE_TYPE (type));
1972 if (TREE_CODE (type) == FUNCTION_TYPE)
1973 return build_pointer_type (type);
1977 /* There are three conditions of builtin candidates:
1979 1) bool-taking candidates. These are the same regardless of the input.
1980 2) pointer-pair taking candidates. These are generated for each type
1981 one of the input types converts to.
1982 3) arithmetic candidates. According to the standard, we should generate
1983 all of these, but I'm trying not to...
1985 Here we generate a superset of the possible candidates for this particular
1986 case. That is a subset of the full set the standard defines, plus some
1987 other cases which the standard disallows. add_builtin_candidate will
1988 filter out the invalid set. */
1991 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
1992 enum tree_code code2, tree fnname, tree *args,
1997 tree type, argtypes[3];
1998 /* TYPES[i] is the set of possible builtin-operator parameter types
1999 we will consider for the Ith argument. These are represented as
2000 a TREE_LIST; the TREE_VALUE of each node is the potential
2004 for (i = 0; i < 3; ++i)
2007 argtypes[i] = lvalue_type (args[i]);
2009 argtypes[i] = NULL_TREE;
2014 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2015 and VQ is either volatile or empty, there exist candidate operator
2016 functions of the form
2017 VQ T& operator++(VQ T&); */
2019 case POSTINCREMENT_EXPR:
2020 case PREINCREMENT_EXPR:
2021 case POSTDECREMENT_EXPR:
2022 case PREDECREMENT_EXPR:
2027 /* 24There also exist candidate operator functions of the form
2028 bool operator!(bool);
2029 bool operator&&(bool, bool);
2030 bool operator||(bool, bool); */
2032 case TRUTH_NOT_EXPR:
2033 build_builtin_candidate
2034 (candidates, fnname, boolean_type_node,
2035 NULL_TREE, args, argtypes, flags);
2038 case TRUTH_ORIF_EXPR:
2039 case TRUTH_ANDIF_EXPR:
2040 build_builtin_candidate
2041 (candidates, fnname, boolean_type_node,
2042 boolean_type_node, args, argtypes, flags);
2064 types[0] = types[1] = NULL_TREE;
2066 for (i = 0; i < 2; ++i)
2070 else if (IS_AGGR_TYPE (argtypes[i]))
2074 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2077 convs = lookup_conversions (argtypes[i]);
2079 if (code == COND_EXPR)
2081 if (real_lvalue_p (args[i]))
2082 types[i] = tree_cons
2083 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2085 types[i] = tree_cons
2086 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2092 for (; convs; convs = TREE_CHAIN (convs))
2094 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2097 && (TREE_CODE (type) != REFERENCE_TYPE
2098 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2101 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2102 types[i] = tree_cons (NULL_TREE, type, types[i]);
2104 type = non_reference (type);
2105 if (i != 0 || ! ref1)
2107 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2108 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2109 types[i] = tree_cons (NULL_TREE, type, types[i]);
2110 if (INTEGRAL_TYPE_P (type))
2111 type = type_promotes_to (type);
2114 if (! value_member (type, types[i]))
2115 types[i] = tree_cons (NULL_TREE, type, types[i]);
2120 if (code == COND_EXPR && real_lvalue_p (args[i]))
2121 types[i] = tree_cons
2122 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2123 type = non_reference (argtypes[i]);
2124 if (i != 0 || ! ref1)
2126 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2127 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2128 types[i] = tree_cons (NULL_TREE, type, types[i]);
2129 if (INTEGRAL_TYPE_P (type))
2130 type = type_promotes_to (type);
2132 types[i] = tree_cons (NULL_TREE, type, types[i]);
2136 /* Run through the possible parameter types of both arguments,
2137 creating candidates with those parameter types. */
2138 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2141 for (type = types[1]; type; type = TREE_CHAIN (type))
2142 add_builtin_candidate
2143 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2144 TREE_VALUE (type), args, argtypes, flags);
2146 add_builtin_candidate
2147 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2148 NULL_TREE, args, argtypes, flags);
2155 /* If TMPL can be successfully instantiated as indicated by
2156 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2158 TMPL is the template. EXPLICIT_TARGS are any explicit template
2159 arguments. ARGLIST is the arguments provided at the call-site.
2160 The RETURN_TYPE is the desired type for conversion operators. If
2161 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2162 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2163 add_conv_candidate. */
2165 static struct z_candidate*
2166 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2167 tree ctype, tree explicit_targs, tree arglist,
2168 tree return_type, tree access_path,
2169 tree conversion_path, int flags, tree obj,
2170 unification_kind_t strict)
2172 int ntparms = DECL_NTPARMS (tmpl);
2173 tree targs = make_tree_vec (ntparms);
2174 tree args_without_in_chrg = arglist;
2175 struct z_candidate *cand;
2179 /* We don't do deduction on the in-charge parameter, the VTT
2180 parameter or 'this'. */
2181 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2182 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2184 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2185 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2186 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2187 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2189 i = fn_type_unification (tmpl, explicit_targs, targs,
2190 args_without_in_chrg,
2191 return_type, strict, -1);
2196 fn = instantiate_template (tmpl, targs, tf_none);
2197 if (fn == error_mark_node)
2202 A member function template is never instantiated to perform the
2203 copy of a class object to an object of its class type.
2205 It's a little unclear what this means; the standard explicitly
2206 does allow a template to be used to copy a class. For example,
2211 template <class T> A(const T&);
2214 void g () { A a (f ()); }
2216 the member template will be used to make the copy. The section
2217 quoted above appears in the paragraph that forbids constructors
2218 whose only parameter is (a possibly cv-qualified variant of) the
2219 class type, and a logical interpretation is that the intent was
2220 to forbid the instantiation of member templates which would then
2222 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2224 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2225 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2230 if (obj != NULL_TREE)
2231 /* Aha, this is a conversion function. */
2232 cand = add_conv_candidate (candidates, fn, obj, access_path,
2233 conversion_path, arglist);
2235 cand = add_function_candidate (candidates, fn, ctype,
2236 arglist, access_path,
2237 conversion_path, flags);
2238 if (DECL_TI_TEMPLATE (fn) != tmpl)
2239 /* This situation can occur if a member template of a template
2240 class is specialized. Then, instantiate_template might return
2241 an instantiation of the specialization, in which case the
2242 DECL_TI_TEMPLATE field will point at the original
2243 specialization. For example:
2245 template <class T> struct S { template <class U> void f(U);
2246 template <> void f(int) {}; };
2250 Here, TMPL will be template <class U> S<double>::f(U).
2251 And, instantiate template will give us the specialization
2252 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2253 for this will point at template <class T> template <> S<T>::f(int),
2254 so that we can find the definition. For the purposes of
2255 overload resolution, however, we want the original TMPL. */
2256 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2258 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2264 static struct z_candidate *
2265 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2266 tree explicit_targs, tree arglist, tree return_type,
2267 tree access_path, tree conversion_path, int flags,
2268 unification_kind_t strict)
2271 add_template_candidate_real (candidates, tmpl, ctype,
2272 explicit_targs, arglist, return_type,
2273 access_path, conversion_path,
2274 flags, NULL_TREE, strict);
2278 static struct z_candidate *
2279 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2280 tree obj, tree arglist, tree return_type,
2281 tree access_path, tree conversion_path)
2284 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2285 arglist, return_type, access_path,
2286 conversion_path, 0, obj, DEDUCE_CONV);
2289 /* The CANDS are the set of candidates that were considered for
2290 overload resolution. Return the set of viable candidates. If none
2291 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2292 is true if a candidate should be considered viable only if it is
2295 static struct z_candidate*
2296 splice_viable (struct z_candidate *cands,
2300 struct z_candidate *viable;
2301 struct z_candidate **last_viable;
2302 struct z_candidate **cand;
2305 last_viable = &viable;
2306 *any_viable_p = false;
2311 struct z_candidate *c = *cand;
2312 if (strict_p ? c->viable == 1 : c->viable)
2317 last_viable = &c->next;
2318 *any_viable_p = true;
2324 return viable ? viable : cands;
2328 any_strictly_viable (struct z_candidate *cands)
2330 for (; cands; cands = cands->next)
2331 if (cands->viable == 1)
2337 build_this (tree obj)
2339 /* Fix this to work on non-lvalues. */
2340 return build_unary_op (ADDR_EXPR, obj, 0);
2343 /* Returns true iff functions are equivalent. Equivalent functions are
2344 not '==' only if one is a function-local extern function or if
2345 both are extern "C". */
2348 equal_functions (tree fn1, tree fn2)
2350 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2351 || DECL_EXTERN_C_FUNCTION_P (fn1))
2352 return decls_match (fn1, fn2);
2356 /* Print information about one overload candidate CANDIDATE. MSGSTR
2357 is the text to print before the candidate itself.
2359 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2360 to have been run through gettext by the caller. This wart makes
2361 life simpler in print_z_candidates and for the translators. */
2364 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2366 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2368 if (candidate->num_convs == 3)
2369 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2370 candidate->convs[0]->type,
2371 candidate->convs[1]->type,
2372 candidate->convs[2]->type);
2373 else if (candidate->num_convs == 2)
2374 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2375 candidate->convs[0]->type,
2376 candidate->convs[1]->type);
2378 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2379 candidate->convs[0]->type);
2381 else if (TYPE_P (candidate->fn))
2382 inform ("%s %T <conversion>", msgstr, candidate->fn);
2383 else if (candidate->viable == -1)
2384 inform ("%J%s %+#D <near match>", candidate->fn, msgstr, candidate->fn);
2386 inform ("%J%s %+#D", candidate->fn, msgstr, candidate->fn);
2390 print_z_candidates (struct z_candidate *candidates)
2393 struct z_candidate *cand1;
2394 struct z_candidate **cand2;
2396 /* There may be duplicates in the set of candidates. We put off
2397 checking this condition as long as possible, since we have no way
2398 to eliminate duplicates from a set of functions in less than n^2
2399 time. Now we are about to emit an error message, so it is more
2400 permissible to go slowly. */
2401 for (cand1 = candidates; cand1; cand1 = cand1->next)
2403 tree fn = cand1->fn;
2404 /* Skip builtin candidates and conversion functions. */
2405 if (TREE_CODE (fn) != FUNCTION_DECL)
2407 cand2 = &cand1->next;
2410 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2411 && equal_functions (fn, (*cand2)->fn))
2412 *cand2 = (*cand2)->next;
2414 cand2 = &(*cand2)->next;
2421 str = _("candidates are:");
2422 print_z_candidate (str, candidates);
2423 if (candidates->next)
2425 /* Indent successive candidates by the width of the translation
2426 of the above string. */
2427 size_t len = gcc_gettext_width (str) + 1;
2428 char *spaces = alloca (len);
2429 memset (spaces, ' ', len-1);
2430 spaces[len - 1] = '\0';
2432 candidates = candidates->next;
2435 print_z_candidate (spaces, candidates);
2436 candidates = candidates->next;
2442 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2443 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2444 the result of the conversion function to convert it to the final
2445 desired type. Merge the the two sequences into a single sequence,
2446 and return the merged sequence. */
2449 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2453 gcc_assert (user_seq->kind == ck_user);
2455 /* Find the end of the second conversion sequence. */
2457 while ((*t)->kind != ck_identity)
2458 t = &((*t)->u.next);
2460 /* Replace the identity conversion with the user conversion
2464 /* The entire sequence is a user-conversion sequence. */
2465 std_seq->user_conv_p = true;
2470 /* Returns the best overload candidate to perform the requested
2471 conversion. This function is used for three the overloading situations
2472 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2473 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2474 per [dcl.init.ref], so we ignore temporary bindings. */
2476 static struct z_candidate *
2477 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2479 struct z_candidate *candidates, *cand;
2480 tree fromtype = TREE_TYPE (expr);
2481 tree ctors = NULL_TREE;
2482 tree conv_fns = NULL_TREE;
2483 conversion *conv = NULL;
2484 tree args = NULL_TREE;
2487 /* We represent conversion within a hierarchy using RVALUE_CONV and
2488 BASE_CONV, as specified by [over.best.ics]; these become plain
2489 constructor calls, as specified in [dcl.init]. */
2490 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2491 || !DERIVED_FROM_P (totype, fromtype));
2493 if (IS_AGGR_TYPE (totype))
2494 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2496 if (IS_AGGR_TYPE (fromtype))
2497 conv_fns = lookup_conversions (fromtype);
2500 flags |= LOOKUP_NO_CONVERSION;
2506 ctors = BASELINK_FUNCTIONS (ctors);
2508 t = build_int_cst (build_pointer_type (totype), 0);
2509 args = build_tree_list (NULL_TREE, expr);
2510 /* We should never try to call the abstract or base constructor
2512 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2513 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2514 args = tree_cons (NULL_TREE, t, args);
2516 for (; ctors; ctors = OVL_NEXT (ctors))
2518 tree ctor = OVL_CURRENT (ctors);
2519 if (DECL_NONCONVERTING_P (ctor))
2522 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2523 cand = add_template_candidate (&candidates, ctor, totype,
2524 NULL_TREE, args, NULL_TREE,
2525 TYPE_BINFO (totype),
2526 TYPE_BINFO (totype),
2530 cand = add_function_candidate (&candidates, ctor, totype,
2531 args, TYPE_BINFO (totype),
2532 TYPE_BINFO (totype),
2536 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2540 args = build_tree_list (NULL_TREE, build_this (expr));
2542 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2545 tree conversion_path = TREE_PURPOSE (conv_fns);
2546 int convflags = LOOKUP_NO_CONVERSION;
2548 /* If we are called to convert to a reference type, we are trying to
2549 find an lvalue binding, so don't even consider temporaries. If
2550 we don't find an lvalue binding, the caller will try again to
2551 look for a temporary binding. */
2552 if (TREE_CODE (totype) == REFERENCE_TYPE)
2553 convflags |= LOOKUP_NO_TEMP_BIND;
2555 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2557 tree fn = OVL_CURRENT (fns);
2559 /* [over.match.funcs] For conversion functions, the function
2560 is considered to be a member of the class of the implicit
2561 object argument for the purpose of defining the type of
2562 the implicit object parameter.
2564 So we pass fromtype as CTYPE to add_*_candidate. */
2566 if (TREE_CODE (fn) == TEMPLATE_DECL)
2567 cand = add_template_candidate (&candidates, fn, fromtype,
2570 TYPE_BINFO (fromtype),
2575 cand = add_function_candidate (&candidates, fn, fromtype,
2577 TYPE_BINFO (fromtype),
2584 = implicit_conversion (totype,
2585 TREE_TYPE (TREE_TYPE (cand->fn)),
2588 cand->second_conv = ics;
2592 else if (candidates->viable == 1 && ics->bad_p)
2598 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2602 cand = tourney (candidates);
2605 if (flags & LOOKUP_COMPLAIN)
2607 error ("conversion from %qT to %qT is ambiguous",
2609 print_z_candidates (candidates);
2612 cand = candidates; /* any one will do */
2613 cand->second_conv = build_ambiguous_conv (totype, expr);
2614 cand->second_conv->user_conv_p = true;
2615 if (!any_strictly_viable (candidates))
2616 cand->second_conv->bad_p = true;
2617 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2618 ambiguous conversion is no worse than another user-defined
2624 /* Build the user conversion sequence. */
2627 (DECL_CONSTRUCTOR_P (cand->fn)
2628 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2629 build_identity_conv (TREE_TYPE (expr), expr));
2632 /* Combine it with the second conversion sequence. */
2633 cand->second_conv = merge_conversion_sequences (conv,
2636 if (cand->viable == -1)
2637 cand->second_conv->bad_p = true;
2643 build_user_type_conversion (tree totype, tree expr, int flags)
2645 struct z_candidate *cand
2646 = build_user_type_conversion_1 (totype, expr, flags);
2650 if (cand->second_conv->kind == ck_ambig)
2651 return error_mark_node;
2652 return convert_from_reference (convert_like (cand->second_conv, expr));
2657 /* Do any initial processing on the arguments to a function call. */
2660 resolve_args (tree args)
2663 for (t = args; t; t = TREE_CHAIN (t))
2665 tree arg = TREE_VALUE (t);
2667 if (arg == error_mark_node)
2668 return error_mark_node;
2669 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2671 error ("invalid use of void expression");
2672 return error_mark_node;
2674 arg = convert_from_reference (arg);
2675 TREE_VALUE (t) = arg;
2680 /* Perform overload resolution on FN, which is called with the ARGS.
2682 Return the candidate function selected by overload resolution, or
2683 NULL if the event that overload resolution failed. In the case
2684 that overload resolution fails, *CANDIDATES will be the set of
2685 candidates considered, and ANY_VIABLE_P will be set to true or
2686 false to indicate whether or not any of the candidates were
2689 The ARGS should already have gone through RESOLVE_ARGS before this
2690 function is called. */
2692 static struct z_candidate *
2693 perform_overload_resolution (tree fn,
2695 struct z_candidate **candidates,
2698 struct z_candidate *cand;
2699 tree explicit_targs = NULL_TREE;
2700 int template_only = 0;
2703 *any_viable_p = true;
2705 /* Check FN and ARGS. */
2706 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2707 || TREE_CODE (fn) == TEMPLATE_DECL
2708 || TREE_CODE (fn) == OVERLOAD
2709 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2710 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2712 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2714 explicit_targs = TREE_OPERAND (fn, 1);
2715 fn = TREE_OPERAND (fn, 0);
2719 /* Add the various candidate functions. */
2720 add_candidates (fn, args, explicit_targs, template_only,
2721 /*conversion_path=*/NULL_TREE,
2722 /*access_path=*/NULL_TREE,
2726 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2730 cand = tourney (*candidates);
2734 /* Return an expression for a call to FN (a namespace-scope function,
2735 or a static member function) with the ARGS. */
2738 build_new_function_call (tree fn, tree args)
2740 struct z_candidate *candidates, *cand;
2745 args = resolve_args (args);
2746 if (args == error_mark_node)
2747 return error_mark_node;
2749 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2750 p = conversion_obstack_alloc (0);
2752 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2756 if (!any_viable_p && candidates && ! candidates->next)
2757 return build_function_call (candidates->fn, args);
2758 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2759 fn = TREE_OPERAND (fn, 0);
2761 error ("no matching function for call to %<%D(%A)%>",
2762 DECL_NAME (OVL_CURRENT (fn)), args);
2764 error ("call of overloaded %<%D(%A)%> is ambiguous",
2765 DECL_NAME (OVL_CURRENT (fn)), args);
2767 print_z_candidates (candidates);
2768 result = error_mark_node;
2771 result = build_over_call (cand, LOOKUP_NORMAL);
2773 /* Free all the conversions we allocated. */
2774 obstack_free (&conversion_obstack, p);
2779 /* Build a call to a global operator new. FNNAME is the name of the
2780 operator (either "operator new" or "operator new[]") and ARGS are
2781 the arguments provided. *SIZE points to the total number of bytes
2782 required by the allocation, and is updated if that is changed here.
2783 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2784 function determines that no cookie should be used, after all,
2785 *COOKIE_SIZE is set to NULL_TREE. */
2788 build_operator_new_call (tree fnname, tree args, tree *size, tree *cookie_size)
2791 struct z_candidate *candidates;
2792 struct z_candidate *cand;
2795 args = tree_cons (NULL_TREE, *size, args);
2796 args = resolve_args (args);
2797 if (args == error_mark_node)
2804 If this lookup fails to find the name, or if the allocated type
2805 is not a class type, the allocation function's name is looked
2806 up in the global scope.
2808 we disregard block-scope declarations of "operator new". */
2809 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2811 /* Figure out what function is being called. */
2812 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2814 /* If no suitable function could be found, issue an error message
2819 error ("no matching function for call to %<%D(%A)%>",
2820 DECL_NAME (OVL_CURRENT (fns)), args);
2822 error ("call of overloaded %<%D(%A)%> is ambiguous",
2823 DECL_NAME (OVL_CURRENT (fns)), args);
2825 print_z_candidates (candidates);
2826 return error_mark_node;
2829 /* If a cookie is required, add some extra space. Whether
2830 or not a cookie is required cannot be determined until
2831 after we know which function was called. */
2834 bool use_cookie = true;
2835 if (!abi_version_at_least (2))
2837 tree placement = TREE_CHAIN (args);
2838 /* In G++ 3.2, the check was implemented incorrectly; it
2839 looked at the placement expression, rather than the
2840 type of the function. */
2841 if (placement && !TREE_CHAIN (placement)
2842 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2850 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2851 /* Skip the size_t parameter. */
2852 arg_types = TREE_CHAIN (arg_types);
2853 /* Check the remaining parameters (if any). */
2855 && TREE_CHAIN (arg_types) == void_list_node
2856 && same_type_p (TREE_VALUE (arg_types),
2860 /* If we need a cookie, adjust the number of bytes allocated. */
2863 /* Update the total size. */
2864 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2865 /* Update the argument list to reflect the adjusted size. */
2866 TREE_VALUE (args) = *size;
2869 *cookie_size = NULL_TREE;
2872 /* Build the CALL_EXPR. */
2873 return build_over_call (cand, LOOKUP_NORMAL);
2877 build_object_call (tree obj, tree args)
2879 struct z_candidate *candidates = 0, *cand;
2880 tree fns, convs, mem_args = NULL_TREE;
2881 tree type = TREE_TYPE (obj);
2883 tree result = NULL_TREE;
2886 if (TYPE_PTRMEMFUNC_P (type))
2888 /* It's no good looking for an overloaded operator() on a
2889 pointer-to-member-function. */
2890 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
2891 return error_mark_node;
2894 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
2895 if (fns == error_mark_node)
2896 return error_mark_node;
2898 args = resolve_args (args);
2900 if (args == error_mark_node)
2901 return error_mark_node;
2903 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2904 p = conversion_obstack_alloc (0);
2908 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
2909 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
2911 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
2913 tree fn = OVL_CURRENT (fns);
2914 if (TREE_CODE (fn) == TEMPLATE_DECL)
2915 add_template_candidate (&candidates, fn, base, NULL_TREE,
2916 mem_args, NULL_TREE,
2919 LOOKUP_NORMAL, DEDUCE_CALL);
2921 add_function_candidate
2922 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
2923 TYPE_BINFO (type), LOOKUP_NORMAL);
2927 convs = lookup_conversions (type);
2929 for (; convs; convs = TREE_CHAIN (convs))
2931 tree fns = TREE_VALUE (convs);
2932 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
2934 if ((TREE_CODE (totype) == POINTER_TYPE
2935 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
2936 || (TREE_CODE (totype) == REFERENCE_TYPE
2937 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
2938 || (TREE_CODE (totype) == REFERENCE_TYPE
2939 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
2940 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
2941 for (; fns; fns = OVL_NEXT (fns))
2943 tree fn = OVL_CURRENT (fns);
2944 if (TREE_CODE (fn) == TEMPLATE_DECL)
2945 add_template_conv_candidate
2946 (&candidates, fn, obj, args, totype,
2947 /*access_path=*/NULL_TREE,
2948 /*conversion_path=*/NULL_TREE);
2950 add_conv_candidate (&candidates, fn, obj, args,
2951 /*conversion_path=*/NULL_TREE,
2952 /*access_path=*/NULL_TREE);
2956 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2959 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
2960 print_z_candidates (candidates);
2961 result = error_mark_node;
2965 cand = tourney (candidates);
2968 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
2969 print_z_candidates (candidates);
2970 result = error_mark_node;
2972 /* Since cand->fn will be a type, not a function, for a conversion
2973 function, we must be careful not to unconditionally look at
2975 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
2976 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
2977 result = build_over_call (cand, LOOKUP_NORMAL);
2980 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
2981 result = build_function_call (obj, args);
2985 /* Free all the conversions we allocated. */
2986 obstack_free (&conversion_obstack, p);
2992 op_error (enum tree_code code, enum tree_code code2,
2993 tree arg1, tree arg2, tree arg3, const char *problem)
2997 if (code == MODIFY_EXPR)
2998 opname = assignment_operator_name_info[code2].name;
3000 opname = operator_name_info[code].name;
3005 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3006 problem, arg1, arg2, arg3);
3009 case POSTINCREMENT_EXPR:
3010 case POSTDECREMENT_EXPR:
3011 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3015 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3020 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3025 error ("%s for %<operator%s%> in %<%E %s %E%>",
3026 problem, opname, arg1, opname, arg2);
3028 error ("%s for %<operator%s%> in %<%s%E%>",
3029 problem, opname, opname, arg1);
3034 /* Return the implicit conversion sequence that could be used to
3035 convert E1 to E2 in [expr.cond]. */
3038 conditional_conversion (tree e1, tree e2)
3040 tree t1 = non_reference (TREE_TYPE (e1));
3041 tree t2 = non_reference (TREE_TYPE (e2));
3047 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3048 implicitly converted (clause _conv_) to the type "reference to
3049 T2", subject to the constraint that in the conversion the
3050 reference must bind directly (_dcl.init.ref_) to E1. */
3051 if (real_lvalue_p (e2))
3053 conv = implicit_conversion (build_reference_type (t2),
3056 LOOKUP_NO_TEMP_BIND);
3063 If E1 and E2 have class type, and the underlying class types are
3064 the same or one is a base class of the other: E1 can be converted
3065 to match E2 if the class of T2 is the same type as, or a base
3066 class of, the class of T1, and the cv-qualification of T2 is the
3067 same cv-qualification as, or a greater cv-qualification than, the
3068 cv-qualification of T1. If the conversion is applied, E1 is
3069 changed to an rvalue of type T2 that still refers to the original
3070 source class object (or the appropriate subobject thereof). */
3071 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3072 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3074 if (good_base && at_least_as_qualified_p (t2, t1))
3076 conv = build_identity_conv (t1, e1);
3077 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3078 TYPE_MAIN_VARIANT (t2)))
3079 conv = build_conv (ck_base, t2, conv);
3081 conv = build_conv (ck_rvalue, t2, conv);
3090 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3091 converted to the type that expression E2 would have if E2 were
3092 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3093 return implicit_conversion (t2, t1, e1, LOOKUP_NORMAL);
3096 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3097 arguments to the conditional expression. */
3100 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3104 tree result = NULL_TREE;
3105 tree result_type = NULL_TREE;
3106 bool lvalue_p = true;
3107 struct z_candidate *candidates = 0;
3108 struct z_candidate *cand;
3111 /* As a G++ extension, the second argument to the conditional can be
3112 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3113 c'.) If the second operand is omitted, make sure it is
3114 calculated only once. */
3118 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3120 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3121 if (real_lvalue_p (arg1))
3122 arg2 = arg1 = stabilize_reference (arg1);
3124 arg2 = arg1 = save_expr (arg1);
3129 The first expr ession is implicitly converted to bool (clause
3131 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3133 /* If something has already gone wrong, just pass that fact up the
3135 if (error_operand_p (arg1)
3136 || error_operand_p (arg2)
3137 || error_operand_p (arg3))
3138 return error_mark_node;
3142 If either the second or the third operand has type (possibly
3143 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3144 array-to-pointer (_conv.array_), and function-to-pointer
3145 (_conv.func_) standard conversions are performed on the second
3146 and third operands. */
3147 arg2_type = TREE_TYPE (arg2);
3148 arg3_type = TREE_TYPE (arg3);
3149 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3151 /* Do the conversions. We don't these for `void' type arguments
3152 since it can't have any effect and since decay_conversion
3153 does not handle that case gracefully. */
3154 if (!VOID_TYPE_P (arg2_type))
3155 arg2 = decay_conversion (arg2);
3156 if (!VOID_TYPE_P (arg3_type))
3157 arg3 = decay_conversion (arg3);
3158 arg2_type = TREE_TYPE (arg2);
3159 arg3_type = TREE_TYPE (arg3);
3163 One of the following shall hold:
3165 --The second or the third operand (but not both) is a
3166 throw-expression (_except.throw_); the result is of the
3167 type of the other and is an rvalue.
3169 --Both the second and the third operands have type void; the
3170 result is of type void and is an rvalue.
3172 We must avoid calling force_rvalue for expressions of type
3173 "void" because it will complain that their value is being
3175 if (TREE_CODE (arg2) == THROW_EXPR
3176 && TREE_CODE (arg3) != THROW_EXPR)
3178 if (!VOID_TYPE_P (arg3_type))
3179 arg3 = force_rvalue (arg3);
3180 arg3_type = TREE_TYPE (arg3);
3181 result_type = arg3_type;
3183 else if (TREE_CODE (arg2) != THROW_EXPR
3184 && TREE_CODE (arg3) == THROW_EXPR)
3186 if (!VOID_TYPE_P (arg2_type))
3187 arg2 = force_rvalue (arg2);
3188 arg2_type = TREE_TYPE (arg2);
3189 result_type = arg2_type;
3191 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3192 result_type = void_type_node;
3195 error ("%qE has type %<void%> and is not a throw-expression",
3196 VOID_TYPE_P (arg2_type) ? arg2 : arg3);
3197 return error_mark_node;
3201 goto valid_operands;
3205 Otherwise, if the second and third operand have different types,
3206 and either has (possibly cv-qualified) class type, an attempt is
3207 made to convert each of those operands to the type of the other. */
3208 else if (!same_type_p (arg2_type, arg3_type)
3209 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3214 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3215 p = conversion_obstack_alloc (0);
3217 conv2 = conditional_conversion (arg2, arg3);
3218 conv3 = conditional_conversion (arg3, arg2);
3222 If both can be converted, or one can be converted but the
3223 conversion is ambiguous, the program is ill-formed. If
3224 neither can be converted, the operands are left unchanged and
3225 further checking is performed as described below. If exactly
3226 one conversion is possible, that conversion is applied to the
3227 chosen operand and the converted operand is used in place of
3228 the original operand for the remainder of this section. */
3229 if ((conv2 && !conv2->bad_p
3230 && conv3 && !conv3->bad_p)
3231 || (conv2 && conv2->kind == ck_ambig)
3232 || (conv3 && conv3->kind == ck_ambig))
3234 error ("operands to ?: have different types");
3235 result = error_mark_node;
3237 else if (conv2 && !conv2->bad_p)
3239 arg2 = convert_like (conv2, arg2);
3240 arg2 = convert_from_reference (arg2);
3241 arg2_type = TREE_TYPE (arg2);
3243 else if (conv3 && !conv3->bad_p)
3245 arg3 = convert_like (conv3, arg3);
3246 arg3 = convert_from_reference (arg3);
3247 arg3_type = TREE_TYPE (arg3);
3250 /* Free all the conversions we allocated. */
3251 obstack_free (&conversion_obstack, p);
3256 /* If, after the conversion, both operands have class type,
3257 treat the cv-qualification of both operands as if it were the
3258 union of the cv-qualification of the operands.
3260 The standard is not clear about what to do in this
3261 circumstance. For example, if the first operand has type
3262 "const X" and the second operand has a user-defined
3263 conversion to "volatile X", what is the type of the second
3264 operand after this step? Making it be "const X" (matching
3265 the first operand) seems wrong, as that discards the
3266 qualification without actually performing a copy. Leaving it
3267 as "volatile X" seems wrong as that will result in the
3268 conditional expression failing altogether, even though,
3269 according to this step, the one operand could be converted to
3270 the type of the other. */
3271 if ((conv2 || conv3)
3272 && CLASS_TYPE_P (arg2_type)
3273 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3274 arg2_type = arg3_type =
3275 cp_build_qualified_type (arg2_type,
3276 TYPE_QUALS (arg2_type)
3277 | TYPE_QUALS (arg3_type));
3282 If the second and third operands are lvalues and have the same
3283 type, the result is of that type and is an lvalue. */
3284 if (real_lvalue_p (arg2)
3285 && real_lvalue_p (arg3)
3286 && same_type_p (arg2_type, arg3_type))
3288 result_type = arg2_type;
3289 goto valid_operands;
3294 Otherwise, the result is an rvalue. If the second and third
3295 operand do not have the same type, and either has (possibly
3296 cv-qualified) class type, overload resolution is used to
3297 determine the conversions (if any) to be applied to the operands
3298 (_over.match.oper_, _over.built_). */
3300 if (!same_type_p (arg2_type, arg3_type)
3301 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3307 /* Rearrange the arguments so that add_builtin_candidate only has
3308 to know about two args. In build_builtin_candidates, the
3309 arguments are unscrambled. */
3313 add_builtin_candidates (&candidates,
3316 ansi_opname (COND_EXPR),
3322 If the overload resolution fails, the program is
3324 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3327 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3328 print_z_candidates (candidates);
3329 return error_mark_node;
3331 cand = tourney (candidates);
3334 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3335 print_z_candidates (candidates);
3336 return error_mark_node;
3341 Otherwise, the conversions thus determined are applied, and
3342 the converted operands are used in place of the original
3343 operands for the remainder of this section. */
3344 conv = cand->convs[0];
3345 arg1 = convert_like (conv, arg1);
3346 conv = cand->convs[1];
3347 arg2 = convert_like (conv, arg2);
3348 conv = cand->convs[2];
3349 arg3 = convert_like (conv, arg3);
3354 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3355 and function-to-pointer (_conv.func_) standard conversions are
3356 performed on the second and third operands.
3358 We need to force the lvalue-to-rvalue conversion here for class types,
3359 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3360 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3363 arg2 = force_rvalue (arg2);
3364 if (!CLASS_TYPE_P (arg2_type))
3365 arg2_type = TREE_TYPE (arg2);
3367 arg3 = force_rvalue (arg3);
3368 if (!CLASS_TYPE_P (arg2_type))
3369 arg3_type = TREE_TYPE (arg3);
3371 if (arg2 == error_mark_node || arg3 == error_mark_node)
3372 return error_mark_node;
3376 After those conversions, one of the following shall hold:
3378 --The second and third operands have the same type; the result is of
3380 if (same_type_p (arg2_type, arg3_type))
3381 result_type = arg2_type;
3384 --The second and third operands have arithmetic or enumeration
3385 type; the usual arithmetic conversions are performed to bring
3386 them to a common type, and the result is of that type. */
3387 else if ((ARITHMETIC_TYPE_P (arg2_type)
3388 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3389 && (ARITHMETIC_TYPE_P (arg3_type)
3390 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3392 /* In this case, there is always a common type. */
3393 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3396 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3397 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3398 warning ("enumeral mismatch in conditional expression: %qT vs %qT",
3399 arg2_type, arg3_type);
3400 else if (extra_warnings
3401 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3402 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3403 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3404 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3405 warning ("enumeral and non-enumeral type in conditional expression");
3407 arg2 = perform_implicit_conversion (result_type, arg2);
3408 arg3 = perform_implicit_conversion (result_type, arg3);
3412 --The second and third operands have pointer type, or one has
3413 pointer type and the other is a null pointer constant; pointer
3414 conversions (_conv.ptr_) and qualification conversions
3415 (_conv.qual_) are performed to bring them to their composite
3416 pointer type (_expr.rel_). The result is of the composite
3419 --The second and third operands have pointer to member type, or
3420 one has pointer to member type and the other is a null pointer
3421 constant; pointer to member conversions (_conv.mem_) and
3422 qualification conversions (_conv.qual_) are performed to bring
3423 them to a common type, whose cv-qualification shall match the
3424 cv-qualification of either the second or the third operand.
3425 The result is of the common type. */
3426 else if ((null_ptr_cst_p (arg2)
3427 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3428 || (null_ptr_cst_p (arg3)
3429 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3430 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3431 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3432 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3434 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3435 arg3, "conditional expression");
3436 if (result_type == error_mark_node)
3437 return error_mark_node;
3438 arg2 = perform_implicit_conversion (result_type, arg2);
3439 arg3 = perform_implicit_conversion (result_type, arg3);
3444 error ("operands to ?: have different types");
3445 return error_mark_node;
3449 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3451 /* We can't use result_type below, as fold might have returned a
3454 /* Expand both sides into the same slot, hopefully the target of the
3455 ?: expression. We used to check for TARGET_EXPRs here, but now we
3456 sometimes wrap them in NOP_EXPRs so the test would fail. */
3457 if (!lvalue_p && CLASS_TYPE_P (TREE_TYPE (result)))
3458 result = get_target_expr (result);
3460 /* If this expression is an rvalue, but might be mistaken for an
3461 lvalue, we must add a NON_LVALUE_EXPR. */
3462 if (!lvalue_p && real_lvalue_p (result))
3463 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
3468 /* OPERAND is an operand to an expression. Perform necessary steps
3469 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3473 prep_operand (tree operand)
3477 operand = convert_from_reference (operand);
3478 if (CLASS_TYPE_P (TREE_TYPE (operand))
3479 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3480 /* Make sure the template type is instantiated now. */
3481 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3487 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3488 OVERLOAD) to the CANDIDATES, returning an updated list of
3489 CANDIDATES. The ARGS are the arguments provided to the call,
3490 without any implicit object parameter. The EXPLICIT_TARGS are
3491 explicit template arguments provided. TEMPLATE_ONLY is true if
3492 only template functions should be considered. CONVERSION_PATH,
3493 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3496 add_candidates (tree fns, tree args,
3497 tree explicit_targs, bool template_only,
3498 tree conversion_path, tree access_path,
3500 struct z_candidate **candidates)
3503 tree non_static_args;
3505 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3506 /* Delay creating the implicit this parameter until it is needed. */
3507 non_static_args = NULL_TREE;
3514 fn = OVL_CURRENT (fns);
3515 /* Figure out which set of arguments to use. */
3516 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3518 /* If this function is a non-static member, prepend the implicit
3519 object parameter. */
3520 if (!non_static_args)
3521 non_static_args = tree_cons (NULL_TREE,
3522 build_this (TREE_VALUE (args)),
3524 fn_args = non_static_args;
3527 /* Otherwise, just use the list of arguments provided. */
3530 if (TREE_CODE (fn) == TEMPLATE_DECL)
3531 add_template_candidate (candidates,
3541 else if (!template_only)
3542 add_function_candidate (candidates,
3549 fns = OVL_NEXT (fns);
3554 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3557 struct z_candidate *candidates = 0, *cand;
3558 tree arglist, fnname;
3560 tree result = NULL_TREE;
3561 bool result_valid_p = false;
3562 enum tree_code code2 = NOP_EXPR;
3568 if (error_operand_p (arg1)
3569 || error_operand_p (arg2)
3570 || error_operand_p (arg3))
3571 return error_mark_node;
3573 if (code == MODIFY_EXPR)
3575 code2 = TREE_CODE (arg3);
3577 fnname = ansi_assopname (code2);
3580 fnname = ansi_opname (code);
3582 arg1 = prep_operand (arg1);
3588 case VEC_DELETE_EXPR:
3590 /* Use build_op_new_call and build_op_delete_call instead. */
3594 return build_object_call (arg1, arg2);
3600 arg2 = prep_operand (arg2);
3601 arg3 = prep_operand (arg3);
3603 if (code == COND_EXPR)
3605 if (arg2 == NULL_TREE
3606 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3607 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3608 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3609 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3612 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3613 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3616 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3617 arg2 = integer_zero_node;
3619 arglist = NULL_TREE;
3621 arglist = tree_cons (NULL_TREE, arg3, arglist);
3623 arglist = tree_cons (NULL_TREE, arg2, arglist);
3624 arglist = tree_cons (NULL_TREE, arg1, arglist);
3626 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3627 p = conversion_obstack_alloc (0);
3629 /* Add namespace-scope operators to the list of functions to
3631 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3632 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3633 flags, &candidates);
3634 /* Add class-member operators to the candidate set. */
3635 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3639 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3640 if (fns == error_mark_node)
3642 result = error_mark_node;
3643 goto user_defined_result_ready;
3646 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3648 BASELINK_BINFO (fns),
3649 TYPE_BINFO (TREE_TYPE (arg1)),
3650 flags, &candidates);
3653 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3654 to know about two args; a builtin candidate will always have a first
3655 parameter of type bool. We'll handle that in
3656 build_builtin_candidate. */
3657 if (code == COND_EXPR)
3667 args[2] = NULL_TREE;
3670 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3676 /* For these, the built-in candidates set is empty
3677 [over.match.oper]/3. We don't want non-strict matches
3678 because exact matches are always possible with built-in
3679 operators. The built-in candidate set for COMPONENT_REF
3680 would be empty too, but since there are no such built-in
3681 operators, we accept non-strict matches for them. */
3686 strict_p = pedantic;
3690 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3695 case POSTINCREMENT_EXPR:
3696 case POSTDECREMENT_EXPR:
3697 /* Look for an `operator++ (int)'. If they didn't have
3698 one, then we fall back to the old way of doing things. */
3699 if (flags & LOOKUP_COMPLAIN)
3700 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3701 "trying prefix operator instead",
3703 operator_name_info[code].name);
3704 if (code == POSTINCREMENT_EXPR)
3705 code = PREINCREMENT_EXPR;
3707 code = PREDECREMENT_EXPR;
3708 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3712 /* The caller will deal with these. */
3717 result_valid_p = true;
3721 if (flags & LOOKUP_COMPLAIN)
3723 op_error (code, code2, arg1, arg2, arg3, "no match");
3724 print_z_candidates (candidates);
3726 result = error_mark_node;
3732 cand = tourney (candidates);
3735 if (flags & LOOKUP_COMPLAIN)
3737 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3738 print_z_candidates (candidates);
3740 result = error_mark_node;
3742 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3745 *overloaded_p = true;
3748 && fnname == ansi_assopname (NOP_EXPR)
3749 && DECL_ARTIFICIAL (cand->fn)
3751 && ! candidates->next->next)
3753 warning ("using synthesized %q#D for copy assignment",
3755 cp_warning_at (" where cfront would use %q#D",
3757 ? candidates->next->fn
3761 result = build_over_call (cand, LOOKUP_NORMAL);
3765 /* Give any warnings we noticed during overload resolution. */
3768 struct candidate_warning *w;
3769 for (w = cand->warnings; w; w = w->next)
3770 joust (cand, w->loser, 1);
3773 /* Check for comparison of different enum types. */
3782 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3783 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3784 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3785 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3787 warning ("comparison between %q#T and %q#T",
3788 TREE_TYPE (arg1), TREE_TYPE (arg2));
3795 /* We need to strip any leading REF_BIND so that bitfields
3796 don't cause errors. This should not remove any important
3797 conversions, because builtins don't apply to class
3798 objects directly. */
3799 conv = cand->convs[0];
3800 if (conv->kind == ck_ref_bind)
3801 conv = conv->u.next;
3802 arg1 = convert_like (conv, arg1);
3805 conv = cand->convs[1];
3806 if (conv->kind == ck_ref_bind)
3807 conv = conv->u.next;
3808 arg2 = convert_like (conv, arg2);
3812 conv = cand->convs[2];
3813 if (conv->kind == ck_ref_bind)
3814 conv = conv->u.next;
3815 arg3 = convert_like (conv, arg3);
3820 user_defined_result_ready:
3822 /* Free all the conversions we allocated. */
3823 obstack_free (&conversion_obstack, p);
3825 if (result || result_valid_p)
3832 return build_modify_expr (arg1, code2, arg2);
3835 return build_indirect_ref (arg1, "unary *");
3840 case TRUNC_DIV_EXPR:
3851 case TRUNC_MOD_EXPR:
3855 case TRUTH_ANDIF_EXPR:
3856 case TRUTH_ORIF_EXPR:
3857 return cp_build_binary_op (code, arg1, arg2);
3862 case TRUTH_NOT_EXPR:
3863 case PREINCREMENT_EXPR:
3864 case POSTINCREMENT_EXPR:
3865 case PREDECREMENT_EXPR:
3866 case POSTDECREMENT_EXPR:
3869 return build_unary_op (code, arg1, candidates != 0);
3872 return build_array_ref (arg1, arg2);
3875 return build_conditional_expr (arg1, arg2, arg3);
3878 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
3880 /* The caller will deal with these. */
3892 /* Build a call to operator delete. This has to be handled very specially,
3893 because the restrictions on what signatures match are different from all
3894 other call instances. For a normal delete, only a delete taking (void *)
3895 or (void *, size_t) is accepted. For a placement delete, only an exact
3896 match with the placement new is accepted.
3898 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
3899 ADDR is the pointer to be deleted.
3900 SIZE is the size of the memory block to be deleted.
3901 GLOBAL_P is true if the delete-expression should not consider
3902 class-specific delete operators.
3903 PLACEMENT is the corresponding placement new call, or NULL_TREE. */
3906 build_op_delete_call (enum tree_code code, tree addr, tree size,
3907 bool global_p, tree placement)
3909 tree fn = NULL_TREE;
3910 tree fns, fnname, argtypes, args, type;
3913 if (addr == error_mark_node)
3914 return error_mark_node;
3916 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
3918 fnname = ansi_opname (code);
3920 if (IS_AGGR_TYPE (type) && !global_p)
3923 If the result of the lookup is ambiguous or inaccessible, or if
3924 the lookup selects a placement deallocation function, the
3925 program is ill-formed.
3927 Therefore, we ask lookup_fnfields to complain about ambiguity. */
3929 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
3930 if (fns == error_mark_node)
3931 return error_mark_node;
3936 if (fns == NULL_TREE)
3937 fns = lookup_name_nonclass (fnname);
3944 /* Find the allocation function that is being called. */
3945 call_expr = placement;
3946 /* Extract the function. */
3947 alloc_fn = get_callee_fndecl (call_expr);
3948 gcc_assert (alloc_fn != NULL_TREE);
3949 /* Then the second parm type. */
3950 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
3951 /* Also the second argument. */
3952 args = TREE_CHAIN (TREE_OPERAND (call_expr, 1));
3956 /* First try it without the size argument. */
3957 argtypes = void_list_node;
3961 /* Strip const and volatile from addr. */
3962 addr = cp_convert (ptr_type_node, addr);
3964 /* We make two tries at finding a matching `operator delete'. On
3965 the first pass, we look for a one-operator (or placement)
3966 operator delete. If we're not doing placement delete, then on
3967 the second pass we look for a two-argument delete. */
3968 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
3970 /* Go through the `operator delete' functions looking for one
3971 with a matching type. */
3972 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
3978 /* The first argument must be "void *". */
3979 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
3980 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
3983 /* On the first pass, check the rest of the arguments. */
3989 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
3997 /* On the second pass, the second argument must be
4000 && same_type_p (TREE_VALUE (t), sizetype)
4001 && TREE_CHAIN (t) == void_list_node)
4005 /* If we found a match, we're done. */
4010 /* If we have a matching function, call it. */
4013 /* Make sure we have the actual function, and not an
4015 fn = OVL_CURRENT (fn);
4017 /* If the FN is a member function, make sure that it is
4019 if (DECL_CLASS_SCOPE_P (fn))
4020 perform_or_defer_access_check (TYPE_BINFO (type), fn);
4023 args = tree_cons (NULL_TREE, addr, args);
4025 args = tree_cons (NULL_TREE, addr,
4026 build_tree_list (NULL_TREE, size));
4030 /* The placement args might not be suitable for overload
4031 resolution at this point, so build the call directly. */
4033 return build_cxx_call (fn, args);
4036 return build_function_call (fn, args);
4039 /* If we are doing placement delete we do nothing if we don't find a
4040 matching op delete. */
4044 error ("no suitable %<operator %s> for %qT",
4045 operator_name_info[(int)code].name, type);
4046 return error_mark_node;
4049 /* If the current scope isn't allowed to access DECL along
4050 BASETYPE_PATH, give an error. The most derived class in
4051 BASETYPE_PATH is the one used to qualify DECL. */
4054 enforce_access (tree basetype_path, tree decl)
4056 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4058 if (!accessible_p (basetype_path, decl, true))
4060 if (TREE_PRIVATE (decl))
4061 cp_error_at ("%q+#D is private", decl);
4062 else if (TREE_PROTECTED (decl))
4063 cp_error_at ("%q+#D is protected", decl);
4065 cp_error_at ("%q+#D is inaccessible", decl);
4066 error ("within this context");
4073 /* Check that a callable constructor to initialize a temporary of
4074 TYPE from an EXPR exists. */
4077 check_constructor_callable (tree type, tree expr)
4079 build_special_member_call (NULL_TREE,
4080 complete_ctor_identifier,
4081 build_tree_list (NULL_TREE, expr),
4083 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4084 | LOOKUP_CONSTRUCTOR_CALLABLE);
4087 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4088 bitwise or of LOOKUP_* values. If any errors are warnings are
4089 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4090 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4094 build_temp (tree expr, tree type, int flags,
4095 void (**diagnostic_fn)(const char *, ...))
4099 savew = warningcount, savee = errorcount;
4100 expr = build_special_member_call (NULL_TREE,
4101 complete_ctor_identifier,
4102 build_tree_list (NULL_TREE, expr),
4104 if (warningcount > savew)
4105 *diagnostic_fn = warning;
4106 else if (errorcount > savee)
4107 *diagnostic_fn = error;
4109 *diagnostic_fn = NULL;
4114 /* Perform the conversions in CONVS on the expression EXPR. FN and
4115 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4116 indicates the `this' argument of a method. INNER is nonzero when
4117 being called to continue a conversion chain. It is negative when a
4118 reference binding will be applied, positive otherwise. If
4119 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4120 conversions will be emitted if appropriate. If C_CAST_P is true,
4121 this conversion is coming from a C-style cast; in that case,
4122 conversions to inaccessible bases are permitted. */
4125 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4126 int inner, bool issue_conversion_warnings,
4129 tree totype = convs->type;
4130 void (*diagnostic_fn)(const char *, ...);
4133 && convs->kind != ck_user
4134 && convs->kind != ck_ambig
4135 && convs->kind != ck_ref_bind)
4137 conversion *t = convs;
4138 for (; t; t = convs->u.next)
4140 if (t->kind == ck_user || !t->bad_p)
4142 expr = convert_like_real (t, expr, fn, argnum, 1,
4143 /*issue_conversion_warnings=*/false,
4144 /*c_cast_p=*/false);
4147 else if (t->kind == ck_ambig)
4148 return convert_like_real (t, expr, fn, argnum, 1,
4149 /*issue_conversion_warnings=*/false,
4150 /*c_cast_p=*/false);
4151 else if (t->kind == ck_identity)
4154 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4156 pedwarn (" initializing argument %P of %qD", argnum, fn);
4157 return cp_convert (totype, expr);
4160 if (issue_conversion_warnings)
4161 expr = dubious_conversion_warnings
4162 (totype, expr, "converting", fn, argnum);
4163 switch (convs->kind)
4167 struct z_candidate *cand = convs->cand;
4168 tree convfn = cand->fn;
4171 if (DECL_CONSTRUCTOR_P (convfn))
4173 tree t = build_int_cst (build_pointer_type (DECL_CONTEXT (convfn)),
4176 args = build_tree_list (NULL_TREE, expr);
4177 /* We should never try to call the abstract or base constructor
4179 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (convfn)
4180 && !DECL_HAS_VTT_PARM_P (convfn));
4181 args = tree_cons (NULL_TREE, t, args);
4184 args = build_this (expr);
4185 expr = build_over_call (cand, LOOKUP_NORMAL);
4187 /* If this is a constructor or a function returning an aggr type,
4188 we need to build up a TARGET_EXPR. */
4189 if (DECL_CONSTRUCTOR_P (convfn))
4190 expr = build_cplus_new (totype, expr);
4192 /* The result of the call is then used to direct-initialize the object
4193 that is the destination of the copy-initialization. [dcl.init]
4195 Note that this step is not reflected in the conversion sequence;
4196 it affects the semantics when we actually perform the
4197 conversion, but is not considered during overload resolution.
4199 If the target is a class, that means call a ctor. */
4200 if (IS_AGGR_TYPE (totype)
4201 && (inner >= 0 || !lvalue_p (expr)))
4205 /* Core issue 84, now a DR, says that we don't
4206 allow UDCs for these args (which deliberately
4207 breaks copy-init of an auto_ptr<Base> from an
4208 auto_ptr<Derived>). */
4209 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4216 (" initializing argument %P of %qD from result of %qD",
4217 argnum, fn, convfn);
4220 (" initializing temporary from result of %qD", convfn);
4222 expr = build_cplus_new (totype, expr);
4227 if (type_unknown_p (expr))
4228 expr = instantiate_type (totype, expr, tf_error | tf_warning);
4229 /* Convert a non-array constant variable to its underlying value, unless we
4230 are about to bind it to a reference, in which case we need to
4231 leave it as an lvalue. */
4233 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
4234 expr = decl_constant_value (expr);
4235 if (convs->check_copy_constructor_p)
4236 check_constructor_callable (totype, expr);
4239 /* Call build_user_type_conversion again for the error. */
4240 return build_user_type_conversion
4241 (totype, convs->u.expr, LOOKUP_NORMAL);
4247 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4248 convs->kind == ck_ref_bind ? -1 : 1,
4249 /*issue_conversion_warnings=*/false,
4251 if (expr == error_mark_node)
4252 return error_mark_node;
4254 switch (convs->kind)
4257 if (! IS_AGGR_TYPE (totype))
4259 /* Else fall through. */
4261 if (convs->kind == ck_base && !convs->need_temporary_p)
4263 /* We are going to bind a reference directly to a base-class
4264 subobject of EXPR. */
4265 if (convs->check_copy_constructor_p)
4266 check_constructor_callable (TREE_TYPE (expr), expr);
4267 /* Build an expression for `*((base*) &expr)'. */
4268 expr = build_unary_op (ADDR_EXPR, expr, 0);
4269 expr = convert_to_base (expr, build_pointer_type (totype),
4270 !c_cast_p, /*nonnull=*/true);
4271 expr = build_indirect_ref (expr, "implicit conversion");
4275 /* Copy-initialization where the cv-unqualified version of the source
4276 type is the same class as, or a derived class of, the class of the
4277 destination [is treated as direct-initialization]. [dcl.init] */
4278 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4280 if (diagnostic_fn && fn)
4281 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4282 return build_cplus_new (totype, expr);
4286 tree ref_type = totype;
4288 /* If necessary, create a temporary. */
4289 if (convs->need_temporary_p || !lvalue_p (expr))
4291 tree type = convs->u.next->type;
4293 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
4295 /* If the reference is volatile or non-const, we
4296 cannot create a temporary. */
4297 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4299 if (lvalue & clk_bitfield)
4300 error ("cannot bind bitfield %qE to %qT",
4302 else if (lvalue & clk_packed)
4303 error ("cannot bind packed field %qE to %qT",
4306 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4307 return error_mark_node;
4309 expr = build_target_expr_with_type (expr, type);
4312 /* Take the address of the thing to which we will bind the
4314 expr = build_unary_op (ADDR_EXPR, expr, 1);
4315 if (expr == error_mark_node)
4316 return error_mark_node;
4318 /* Convert it to a pointer to the type referred to by the
4319 reference. This will adjust the pointer if a derived to
4320 base conversion is being performed. */
4321 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4323 /* Convert the pointer to the desired reference type. */
4324 return build_nop (ref_type, expr);
4328 return decay_conversion (expr);
4331 /* Warn about deprecated conversion if appropriate. */
4332 string_conv_p (totype, expr, 1);
4337 expr = convert_to_base (expr, totype, !c_cast_p,
4339 return build_nop (totype, expr);
4342 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4348 return ocp_convert (totype, expr, CONV_IMPLICIT,
4349 LOOKUP_NORMAL|LOOKUP_NO_CONVERSION);
4352 /* Build a call to __builtin_trap. */
4355 call_builtin_trap (void)
4357 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4359 gcc_assert (fn != NULL);
4360 fn = build_call (fn, NULL_TREE);
4364 /* ARG is being passed to a varargs function. Perform any conversions
4365 required. Return the converted value. */
4368 convert_arg_to_ellipsis (tree arg)
4372 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4373 standard conversions are performed. */
4374 arg = decay_conversion (arg);
4377 If the argument has integral or enumeration type that is subject
4378 to the integral promotions (_conv.prom_), or a floating point
4379 type that is subject to the floating point promotion
4380 (_conv.fpprom_), the value of the argument is converted to the
4381 promoted type before the call. */
4382 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4383 && (TYPE_PRECISION (TREE_TYPE (arg))
4384 < TYPE_PRECISION (double_type_node)))
4385 arg = convert_to_real (double_type_node, arg);
4386 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4387 arg = perform_integral_promotions (arg);
4389 arg = require_complete_type (arg);
4391 if (arg != error_mark_node
4392 && !pod_type_p (TREE_TYPE (arg)))
4394 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4395 here and do a bitwise copy, but now cp_expr_size will abort if we
4397 If the call appears in the context of a sizeof expression,
4398 there is no need to emit a warning, since the expression won't be
4399 evaluated. We keep the builtin_trap just as a safety check. */
4400 if (!skip_evaluation)
4401 warning ("cannot pass objects of non-POD type %q#T through %<...%>; "
4402 "call will abort at runtime", TREE_TYPE (arg));
4403 arg = call_builtin_trap ();
4404 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4411 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4414 build_x_va_arg (tree expr, tree type)
4416 if (processing_template_decl)
4417 return build_min (VA_ARG_EXPR, type, expr);
4419 type = complete_type_or_else (type, NULL_TREE);
4421 if (expr == error_mark_node || !type)
4422 return error_mark_node;
4424 if (! pod_type_p (type))
4426 /* Undefined behavior [expr.call] 5.2.2/7. */
4427 warning ("cannot receive objects of non-POD type %q#T through %<...%>; "
4428 "call will abort at runtime", type);
4429 expr = convert (build_pointer_type (type), null_node);
4430 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4431 call_builtin_trap (), expr);
4432 expr = build_indirect_ref (expr, NULL);
4436 return build_va_arg (expr, type);
4439 /* TYPE has been given to va_arg. Apply the default conversions which
4440 would have happened when passed via ellipsis. Return the promoted
4441 type, or the passed type if there is no change. */
4444 cxx_type_promotes_to (tree type)
4448 /* Perform the array-to-pointer and function-to-pointer
4450 type = type_decays_to (type);
4452 promote = type_promotes_to (type);
4453 if (same_type_p (type, promote))
4459 /* ARG is a default argument expression being passed to a parameter of
4460 the indicated TYPE, which is a parameter to FN. Do any required
4461 conversions. Return the converted value. */
4464 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4466 /* If the ARG is an unparsed default argument expression, the
4467 conversion cannot be performed. */
4468 if (TREE_CODE (arg) == DEFAULT_ARG)
4470 error ("the default argument for parameter %d of %qD has "
4471 "not yet been parsed",
4473 return error_mark_node;
4476 if (fn && DECL_TEMPLATE_INFO (fn))
4477 arg = tsubst_default_argument (fn, type, arg);
4479 arg = break_out_target_exprs (arg);
4481 if (TREE_CODE (arg) == CONSTRUCTOR)
4483 arg = digest_init (type, arg, 0);
4484 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4485 "default argument", fn, parmnum);
4489 /* This could get clobbered by the following call. */
4490 if (TREE_HAS_CONSTRUCTOR (arg))
4491 arg = copy_node (arg);
4493 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4494 "default argument", fn, parmnum);
4495 arg = convert_for_arg_passing (type, arg);
4501 /* Returns the type which will really be used for passing an argument of
4505 type_passed_as (tree type)
4507 /* Pass classes with copy ctors by invisible reference. */
4508 if (TREE_ADDRESSABLE (type))
4510 type = build_reference_type (type);
4511 /* There are no other pointers to this temporary. */
4512 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4514 else if (targetm.calls.promote_prototypes (type)
4515 && INTEGRAL_TYPE_P (type)
4516 && COMPLETE_TYPE_P (type)
4517 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4518 TYPE_SIZE (integer_type_node)))
4519 type = integer_type_node;
4524 /* Actually perform the appropriate conversion. */
4527 convert_for_arg_passing (tree type, tree val)
4529 if (val == error_mark_node)
4531 /* Pass classes with copy ctors by invisible reference. */
4532 else if (TREE_ADDRESSABLE (type))
4533 val = build1 (ADDR_EXPR, build_reference_type (type), val);
4534 else if (targetm.calls.promote_prototypes (type)
4535 && INTEGRAL_TYPE_P (type)
4536 && COMPLETE_TYPE_P (type)
4537 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4538 TYPE_SIZE (integer_type_node)))
4539 val = perform_integral_promotions (val);
4543 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4544 which no conversions at all should be done. This is true for some
4545 builtins which don't act like normal functions. */
4548 magic_varargs_p (tree fn)
4550 if (DECL_BUILT_IN (fn))
4551 switch (DECL_FUNCTION_CODE (fn))
4553 case BUILT_IN_CLASSIFY_TYPE:
4554 case BUILT_IN_CONSTANT_P:
4555 case BUILT_IN_NEXT_ARG:
4556 case BUILT_IN_STDARG_START:
4557 case BUILT_IN_VA_START:
4566 /* Subroutine of the various build_*_call functions. Overload resolution
4567 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4568 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4569 bitmask of various LOOKUP_* flags which apply to the call itself. */
4572 build_over_call (struct z_candidate *cand, int flags)
4575 tree args = cand->args;
4576 conversion **convs = cand->convs;
4578 tree converted_args = NULL_TREE;
4579 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4584 /* In a template, there is no need to perform all of the work that
4585 is normally done. We are only interested in the type of the call
4586 expression, i.e., the return type of the function. Any semantic
4587 errors will be deferred until the template is instantiated. */
4588 if (processing_template_decl)
4592 return_type = TREE_TYPE (TREE_TYPE (fn));
4593 expr = build3 (CALL_EXPR, return_type, fn, args, NULL_TREE);
4594 if (TREE_THIS_VOLATILE (fn) && cfun)
4595 current_function_returns_abnormally = 1;
4596 if (!VOID_TYPE_P (return_type))
4597 require_complete_type (return_type);
4598 return convert_from_reference (expr);
4601 /* Give any warnings we noticed during overload resolution. */
4604 struct candidate_warning *w;
4605 for (w = cand->warnings; w; w = w->next)
4606 joust (cand, w->loser, 1);
4609 if (DECL_FUNCTION_MEMBER_P (fn))
4611 /* If FN is a template function, two cases must be considered.
4616 template <class T> void f();
4618 template <class T> struct B {
4622 struct C : A, B<int> {
4624 using B<int>::g; // #2
4627 In case #1 where `A::f' is a member template, DECL_ACCESS is
4628 recorded in the primary template but not in its specialization.
4629 We check access of FN using its primary template.
4631 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4632 because it is a member of class template B, DECL_ACCESS is
4633 recorded in the specialization `B<int>::g'. We cannot use its
4634 primary template because `B<T>::g' and `B<int>::g' may have
4635 different access. */
4636 if (DECL_TEMPLATE_INFO (fn)
4637 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4638 perform_or_defer_access_check (cand->access_path,
4639 DECL_TI_TEMPLATE (fn));
4641 perform_or_defer_access_check (cand->access_path, fn);
4644 if (args && TREE_CODE (args) != TREE_LIST)
4645 args = build_tree_list (NULL_TREE, args);
4648 /* The implicit parameters to a constructor are not considered by overload
4649 resolution, and must be of the proper type. */
4650 if (DECL_CONSTRUCTOR_P (fn))
4652 converted_args = tree_cons (NULL_TREE, TREE_VALUE (arg), converted_args);
4653 arg = TREE_CHAIN (arg);
4654 parm = TREE_CHAIN (parm);
4655 /* We should never try to call the abstract constructor. */
4656 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4658 if (DECL_HAS_VTT_PARM_P (fn))
4660 converted_args = tree_cons
4661 (NULL_TREE, TREE_VALUE (arg), converted_args);
4662 arg = TREE_CHAIN (arg);
4663 parm = TREE_CHAIN (parm);
4666 /* Bypass access control for 'this' parameter. */
4667 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4669 tree parmtype = TREE_VALUE (parm);
4670 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4674 if (convs[i]->bad_p)
4675 pedwarn ("passing %qT as %<this%> argument of %q#D discards qualifiers",
4676 TREE_TYPE (argtype), fn);
4678 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4679 X is called for an object that is not of type X, or of a type
4680 derived from X, the behavior is undefined.
4682 So we can assume that anything passed as 'this' is non-null, and
4683 optimize accordingly. */
4684 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4685 /* Convert to the base in which the function was declared. */
4686 gcc_assert (cand->conversion_path != NULL_TREE);
4687 converted_arg = build_base_path (PLUS_EXPR,
4689 cand->conversion_path,
4691 /* Check that the base class is accessible. */
4692 if (!accessible_base_p (TREE_TYPE (argtype),
4693 BINFO_TYPE (cand->conversion_path), true))
4694 error ("%qT is not an accessible base of %qT",
4695 BINFO_TYPE (cand->conversion_path),
4696 TREE_TYPE (argtype));
4697 /* If fn was found by a using declaration, the conversion path
4698 will be to the derived class, not the base declaring fn. We
4699 must convert from derived to base. */
4700 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4701 TREE_TYPE (parmtype), ba_unique, NULL);
4702 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4705 converted_args = tree_cons (NULL_TREE, converted_arg, converted_args);
4706 parm = TREE_CHAIN (parm);
4707 arg = TREE_CHAIN (arg);
4713 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4715 tree type = TREE_VALUE (parm);
4718 val = convert_like_with_context
4719 (conv, TREE_VALUE (arg), fn, i - is_method);
4721 val = convert_for_arg_passing (type, val);
4722 converted_args = tree_cons (NULL_TREE, val, converted_args);
4725 /* Default arguments */
4726 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
4728 = tree_cons (NULL_TREE,
4729 convert_default_arg (TREE_VALUE (parm),
4730 TREE_PURPOSE (parm),
4735 for (; arg; arg = TREE_CHAIN (arg))
4737 tree a = TREE_VALUE (arg);
4738 if (magic_varargs_p (fn))
4739 /* Do no conversions for magic varargs. */;
4741 a = convert_arg_to_ellipsis (a);
4742 converted_args = tree_cons (NULL_TREE, a, converted_args);
4745 converted_args = nreverse (converted_args);
4747 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
4750 /* Avoid actually calling copy constructors and copy assignment operators,
4753 if (! flag_elide_constructors)
4754 /* Do things the hard way. */;
4755 else if (cand->num_convs == 1 && DECL_COPY_CONSTRUCTOR_P (fn))
4758 arg = skip_artificial_parms_for (fn, converted_args);
4759 arg = TREE_VALUE (arg);
4761 /* Pull out the real argument, disregarding const-correctness. */
4763 while (TREE_CODE (targ) == NOP_EXPR
4764 || TREE_CODE (targ) == NON_LVALUE_EXPR
4765 || TREE_CODE (targ) == CONVERT_EXPR)
4766 targ = TREE_OPERAND (targ, 0);
4767 if (TREE_CODE (targ) == ADDR_EXPR)
4769 targ = TREE_OPERAND (targ, 0);
4770 if (!same_type_ignoring_top_level_qualifiers_p
4771 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
4780 arg = build_indirect_ref (arg, 0);
4782 /* [class.copy]: the copy constructor is implicitly defined even if
4783 the implementation elided its use. */
4784 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
4787 /* If we're creating a temp and we already have one, don't create a
4788 new one. If we're not creating a temp but we get one, use
4789 INIT_EXPR to collapse the temp into our target. Otherwise, if the
4790 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
4791 temp or an INIT_EXPR otherwise. */
4792 if (integer_zerop (TREE_VALUE (args)))
4794 if (TREE_CODE (arg) == TARGET_EXPR)
4796 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4797 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
4799 else if (TREE_CODE (arg) == TARGET_EXPR
4800 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4802 tree to = stabilize_reference
4803 (build_indirect_ref (TREE_VALUE (args), 0));
4805 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
4809 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
4811 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
4813 tree to = stabilize_reference
4814 (build_indirect_ref (TREE_VALUE (converted_args), 0));
4815 tree type = TREE_TYPE (to);
4816 tree as_base = CLASSTYPE_AS_BASE (type);
4818 arg = TREE_VALUE (TREE_CHAIN (converted_args));
4819 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
4821 arg = build_indirect_ref (arg, 0);
4822 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
4826 /* We must only copy the non-tail padding parts.
4827 Use __builtin_memcpy for the bitwise copy. */
4831 args = tree_cons (NULL, TYPE_SIZE_UNIT (as_base), NULL);
4832 args = tree_cons (NULL, arg, args);
4833 t = build_unary_op (ADDR_EXPR, to, 0);
4834 args = tree_cons (NULL, t, args);
4835 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
4836 t = build_call (t, args);
4838 t = convert (TREE_TYPE (TREE_VALUE (args)), t);
4839 val = build_indirect_ref (t, 0);
4847 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
4849 tree t, *p = &TREE_VALUE (converted_args);
4850 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (*p)),
4853 gcc_assert (binfo && binfo != error_mark_node);
4855 *p = build_base_path (PLUS_EXPR, *p, binfo, 1);
4856 if (TREE_SIDE_EFFECTS (*p))
4857 *p = save_expr (*p);
4858 t = build_pointer_type (TREE_TYPE (fn));
4859 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
4860 fn = build_java_interface_fn_ref (fn, *p);
4862 fn = build_vfn_ref (*p, DECL_VINDEX (fn));
4865 else if (DECL_INLINE (fn))
4866 fn = inline_conversion (fn);
4868 fn = build_addr_func (fn);
4870 return build_cxx_call (fn, converted_args);
4873 /* Build and return a call to FN, using ARGS. This function performs
4874 no overload resolution, conversion, or other high-level
4878 build_cxx_call (tree fn, tree args)
4882 fn = build_call (fn, args);
4884 /* If this call might throw an exception, note that fact. */
4885 fndecl = get_callee_fndecl (fn);
4886 if ((!fndecl || !TREE_NOTHROW (fndecl))
4887 && at_function_scope_p ()
4889 cp_function_chain->can_throw = 1;
4891 /* Some built-in function calls will be evaluated at compile-time in
4893 fn = fold_if_not_in_template (fn);
4895 if (VOID_TYPE_P (TREE_TYPE (fn)))
4898 fn = require_complete_type (fn);
4899 if (fn == error_mark_node)
4900 return error_mark_node;
4902 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
4903 fn = build_cplus_new (TREE_TYPE (fn), fn);
4904 return convert_from_reference (fn);
4907 static GTY(()) tree java_iface_lookup_fn;
4909 /* Make an expression which yields the address of the Java interface
4910 method FN. This is achieved by generating a call to libjava's
4911 _Jv_LookupInterfaceMethodIdx(). */
4914 build_java_interface_fn_ref (tree fn, tree instance)
4916 tree lookup_args, lookup_fn, method, idx;
4917 tree klass_ref, iface, iface_ref;
4920 if (!java_iface_lookup_fn)
4922 tree endlink = build_void_list_node ();
4923 tree t = tree_cons (NULL_TREE, ptr_type_node,
4924 tree_cons (NULL_TREE, ptr_type_node,
4925 tree_cons (NULL_TREE, java_int_type_node,
4927 java_iface_lookup_fn
4928 = builtin_function ("_Jv_LookupInterfaceMethodIdx",
4929 build_function_type (ptr_type_node, t),
4930 0, NOT_BUILT_IN, NULL, NULL_TREE);
4933 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
4934 This is the first entry in the vtable. */
4935 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
4938 /* Get the java.lang.Class pointer for the interface being called. */
4939 iface = DECL_CONTEXT (fn);
4940 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
4941 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
4942 || DECL_CONTEXT (iface_ref) != iface)
4944 error ("could not find class$ field in java interface type %qT",
4946 return error_mark_node;
4948 iface_ref = build_address (iface_ref);
4949 iface_ref = convert (build_pointer_type (iface), iface_ref);
4951 /* Determine the itable index of FN. */
4953 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
4955 if (!DECL_VIRTUAL_P (method))
4961 idx = build_int_cst (NULL_TREE, i);
4963 lookup_args = tree_cons (NULL_TREE, klass_ref,
4964 tree_cons (NULL_TREE, iface_ref,
4965 build_tree_list (NULL_TREE, idx)));
4966 lookup_fn = build1 (ADDR_EXPR,
4967 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
4968 java_iface_lookup_fn);
4969 return build3 (CALL_EXPR, ptr_type_node, lookup_fn, lookup_args, NULL_TREE);
4972 /* Returns the value to use for the in-charge parameter when making a
4973 call to a function with the indicated NAME.
4975 FIXME:Can't we find a neater way to do this mapping? */
4978 in_charge_arg_for_name (tree name)
4980 if (name == base_ctor_identifier
4981 || name == base_dtor_identifier)
4982 return integer_zero_node;
4983 else if (name == complete_ctor_identifier)
4984 return integer_one_node;
4985 else if (name == complete_dtor_identifier)
4986 return integer_two_node;
4987 else if (name == deleting_dtor_identifier)
4988 return integer_three_node;
4990 /* This function should only be called with one of the names listed
4996 /* Build a call to a constructor, destructor, or an assignment
4997 operator for INSTANCE, an expression with class type. NAME
4998 indicates the special member function to call; ARGS are the
4999 arguments. BINFO indicates the base of INSTANCE that is to be
5000 passed as the `this' parameter to the member function called.
5002 FLAGS are the LOOKUP_* flags to use when processing the call.
5004 If NAME indicates a complete object constructor, INSTANCE may be
5005 NULL_TREE. In this case, the caller will call build_cplus_new to
5006 store the newly constructed object into a VAR_DECL. */
5009 build_special_member_call (tree instance, tree name, tree args,
5010 tree binfo, int flags)
5013 /* The type of the subobject to be constructed or destroyed. */
5016 gcc_assert (name == complete_ctor_identifier
5017 || name == base_ctor_identifier
5018 || name == complete_dtor_identifier
5019 || name == base_dtor_identifier
5020 || name == deleting_dtor_identifier
5021 || name == ansi_assopname (NOP_EXPR));
5024 /* Resolve the name. */
5025 if (!complete_type_or_else (binfo, NULL_TREE))
5026 return error_mark_node;
5028 binfo = TYPE_BINFO (binfo);
5031 gcc_assert (binfo != NULL_TREE);
5033 class_type = BINFO_TYPE (binfo);
5035 /* Handle the special case where INSTANCE is NULL_TREE. */
5036 if (name == complete_ctor_identifier && !instance)
5038 instance = build_int_cst (build_pointer_type (class_type), 0);
5039 instance = build1 (INDIRECT_REF, class_type, instance);
5043 if (name == complete_dtor_identifier
5044 || name == base_dtor_identifier
5045 || name == deleting_dtor_identifier)
5046 gcc_assert (args == NULL_TREE);
5048 /* Convert to the base class, if necessary. */
5049 if (!same_type_ignoring_top_level_qualifiers_p
5050 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5052 if (name != ansi_assopname (NOP_EXPR))
5053 /* For constructors and destructors, either the base is
5054 non-virtual, or it is virtual but we are doing the
5055 conversion from a constructor or destructor for the
5056 complete object. In either case, we can convert
5058 instance = convert_to_base_statically (instance, binfo);
5060 /* However, for assignment operators, we must convert
5061 dynamically if the base is virtual. */
5062 instance = build_base_path (PLUS_EXPR, instance,
5063 binfo, /*nonnull=*/1);
5067 gcc_assert (instance != NULL_TREE);
5069 fns = lookup_fnfields (binfo, name, 1);
5071 /* When making a call to a constructor or destructor for a subobject
5072 that uses virtual base classes, pass down a pointer to a VTT for
5074 if ((name == base_ctor_identifier
5075 || name == base_dtor_identifier)
5076 && CLASSTYPE_VBASECLASSES (class_type))
5081 /* If the current function is a complete object constructor
5082 or destructor, then we fetch the VTT directly.
5083 Otherwise, we look it up using the VTT we were given. */
5084 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5085 vtt = decay_conversion (vtt);
5086 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5087 build2 (EQ_EXPR, boolean_type_node,
5088 current_in_charge_parm, integer_zero_node),
5091 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5092 sub_vtt = build2 (PLUS_EXPR, TREE_TYPE (vtt), vtt,
5093 BINFO_SUBVTT_INDEX (binfo));
5095 args = tree_cons (NULL_TREE, sub_vtt, args);
5098 return build_new_method_call (instance, fns, args,
5099 TYPE_BINFO (BINFO_TYPE (binfo)),
5103 /* Return the NAME, as a C string. The NAME indicates a function that
5104 is a member of TYPE. *FREE_P is set to true if the caller must
5105 free the memory returned.
5107 Rather than go through all of this, we should simply set the names
5108 of constructors and destructors appropriately, and dispense with
5109 ctor_identifier, dtor_identifier, etc. */
5112 name_as_c_string (tree name, tree type, bool *free_p)
5116 /* Assume that we will not allocate memory. */
5118 /* Constructors and destructors are special. */
5119 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5122 = (char *) IDENTIFIER_POINTER (constructor_name (type));
5123 /* For a destructor, add the '~'. */
5124 if (name == complete_dtor_identifier
5125 || name == base_dtor_identifier
5126 || name == deleting_dtor_identifier)
5128 pretty_name = concat ("~", pretty_name, NULL);
5129 /* Remember that we need to free the memory allocated. */
5133 else if (IDENTIFIER_TYPENAME_P (name))
5135 pretty_name = concat ("operator ",
5136 type_as_string (TREE_TYPE (name),
5137 TFF_PLAIN_IDENTIFIER),
5139 /* Remember that we need to free the memory allocated. */
5143 pretty_name = (char *) IDENTIFIER_POINTER (name);
5148 /* Build a call to "INSTANCE.FN (ARGS)". */
5151 build_new_method_call (tree instance, tree fns, tree args,
5152 tree conversion_path, int flags)
5154 struct z_candidate *candidates = 0, *cand;
5155 tree explicit_targs = NULL_TREE;
5156 tree basetype = NULL_TREE;
5159 tree mem_args = NULL_TREE, instance_ptr;
5165 int template_only = 0;
5172 gcc_assert (instance != NULL_TREE);
5174 if (error_operand_p (instance)
5175 || error_operand_p (fns)
5176 || args == error_mark_node)
5177 return error_mark_node;
5179 orig_instance = instance;
5183 if (processing_template_decl)
5185 instance = build_non_dependent_expr (instance);
5186 if (!BASELINK_P (fns)
5187 && TREE_CODE (fns) != PSEUDO_DTOR_EXPR
5188 && TREE_TYPE (fns) != unknown_type_node)
5189 fns = build_non_dependent_expr (fns);
5190 args = build_non_dependent_args (orig_args);
5193 /* Process the argument list. */
5195 args = resolve_args (args);
5196 if (args == error_mark_node)
5197 return error_mark_node;
5199 if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5200 instance = convert_from_reference (instance);
5201 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5202 instance_ptr = build_this (instance);
5204 if (!BASELINK_P (fns))
5206 error ("call to non-function %qD", fns);
5207 return error_mark_node;
5210 if (!conversion_path)
5211 conversion_path = BASELINK_BINFO (fns);
5212 access_binfo = BASELINK_ACCESS_BINFO (fns);
5213 optype = BASELINK_OPTYPE (fns);
5214 fns = BASELINK_FUNCTIONS (fns);
5216 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5218 explicit_targs = TREE_OPERAND (fns, 1);
5219 fns = TREE_OPERAND (fns, 0);
5223 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5224 || TREE_CODE (fns) == TEMPLATE_DECL
5225 || TREE_CODE (fns) == OVERLOAD);
5227 /* XXX this should be handled before we get here. */
5228 if (! IS_AGGR_TYPE (basetype))
5230 if ((flags & LOOKUP_COMPLAIN) && basetype != error_mark_node)
5231 error ("request for member %qD in %qE, which is of non-aggregate "
5233 fns, instance, basetype);
5235 return error_mark_node;
5238 fn = get_first_fn (fns);
5239 name = DECL_NAME (fn);
5241 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5243 /* Callers should explicitly indicate whether they want to construct
5244 the complete object or just the part without virtual bases. */
5245 gcc_assert (name != ctor_identifier);
5246 /* Similarly for destructors. */
5247 gcc_assert (name != dtor_identifier);
5250 /* It's OK to call destructors on cv-qualified objects. Therefore,
5251 convert the INSTANCE_PTR to the unqualified type, if necessary. */
5252 if (DECL_DESTRUCTOR_P (fn))
5254 tree type = build_pointer_type (basetype);
5255 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5256 instance_ptr = build_nop (type, instance_ptr);
5259 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5260 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5262 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5263 p = conversion_obstack_alloc (0);
5265 for (fn = fns; fn; fn = OVL_NEXT (fn))
5267 tree t = OVL_CURRENT (fn);
5270 /* We can end up here for copy-init of same or base class. */
5271 if ((flags & LOOKUP_ONLYCONVERTING)
5272 && DECL_NONCONVERTING_P (t))
5275 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5276 this_arglist = mem_args;
5278 this_arglist = args;
5280 if (TREE_CODE (t) == TEMPLATE_DECL)
5281 /* A member template. */
5282 add_template_candidate (&candidates, t,
5285 this_arglist, optype,
5290 else if (! template_only)
5291 add_function_candidate (&candidates, t,
5299 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5302 if (!COMPLETE_TYPE_P (basetype))
5303 cxx_incomplete_type_error (instance_ptr, basetype);
5309 pretty_name = name_as_c_string (name, basetype, &free_p);
5310 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5311 basetype, pretty_name, user_args,
5312 TREE_TYPE (TREE_TYPE (instance_ptr)));
5316 print_z_candidates (candidates);
5317 call = error_mark_node;
5321 cand = tourney (candidates);
5327 pretty_name = name_as_c_string (name, basetype, &free_p);
5328 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5330 print_z_candidates (candidates);
5333 call = error_mark_node;
5337 if (!(flags & LOOKUP_NONVIRTUAL)
5338 && DECL_PURE_VIRTUAL_P (cand->fn)
5339 && instance == current_class_ref
5340 && (DECL_CONSTRUCTOR_P (current_function_decl)
5341 || DECL_DESTRUCTOR_P (current_function_decl)))
5342 /* This is not an error, it is runtime undefined
5344 warning ((DECL_CONSTRUCTOR_P (current_function_decl) ?
5345 "abstract virtual %q#D called from constructor"
5346 : "abstract virtual %q#D called from destructor"),
5349 if (TREE_CODE (TREE_TYPE (cand->fn)) == METHOD_TYPE
5350 && is_dummy_object (instance_ptr))
5352 error ("cannot call member function %qD without object",
5354 call = error_mark_node;
5358 if (DECL_VINDEX (cand->fn) && ! (flags & LOOKUP_NONVIRTUAL)
5359 && resolves_to_fixed_type_p (instance, 0))
5360 flags |= LOOKUP_NONVIRTUAL;
5362 call = build_over_call (cand, flags);
5364 /* In an expression of the form `a->f()' where `f' turns
5365 out to be a static member function, `a' is
5366 none-the-less evaluated. */
5367 if (TREE_CODE (TREE_TYPE (cand->fn)) != METHOD_TYPE
5368 && !is_dummy_object (instance_ptr)
5369 && TREE_SIDE_EFFECTS (instance))
5370 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5376 if (processing_template_decl && call != error_mark_node)
5377 call = (build_min_non_dep
5379 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5380 orig_args, NULL_TREE));
5382 /* Free all the conversions we allocated. */
5383 obstack_free (&conversion_obstack, p);
5388 /* Returns true iff standard conversion sequence ICS1 is a proper
5389 subsequence of ICS2. */
5392 is_subseq (conversion *ics1, conversion *ics2)
5394 /* We can assume that a conversion of the same code
5395 between the same types indicates a subsequence since we only get
5396 here if the types we are converting from are the same. */
5398 while (ics1->kind == ck_rvalue
5399 || ics1->kind == ck_lvalue)
5400 ics1 = ics1->u.next;
5404 while (ics2->kind == ck_rvalue
5405 || ics2->kind == ck_lvalue)
5406 ics2 = ics2->u.next;
5408 if (ics2->kind == ck_user
5409 || ics2->kind == ck_ambig
5410 || ics2->kind == ck_identity)
5411 /* At this point, ICS1 cannot be a proper subsequence of
5412 ICS2. We can get a USER_CONV when we are comparing the
5413 second standard conversion sequence of two user conversion
5417 ics2 = ics2->u.next;
5419 if (ics2->kind == ics1->kind
5420 && same_type_p (ics2->type, ics1->type)
5421 && same_type_p (ics2->u.next->type,
5422 ics1->u.next->type))
5427 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5428 be any _TYPE nodes. */
5431 is_properly_derived_from (tree derived, tree base)
5433 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5434 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5437 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5438 considers every class derived from itself. */
5439 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5440 && DERIVED_FROM_P (base, derived));
5443 /* We build the ICS for an implicit object parameter as a pointer
5444 conversion sequence. However, such a sequence should be compared
5445 as if it were a reference conversion sequence. If ICS is the
5446 implicit conversion sequence for an implicit object parameter,
5447 modify it accordingly. */
5450 maybe_handle_implicit_object (conversion **ics)
5454 /* [over.match.funcs]
5456 For non-static member functions, the type of the
5457 implicit object parameter is "reference to cv X"
5458 where X is the class of which the function is a
5459 member and cv is the cv-qualification on the member
5460 function declaration. */
5461 conversion *t = *ics;
5462 tree reference_type;
5464 /* The `this' parameter is a pointer to a class type. Make the
5465 implicit conversion talk about a reference to that same class
5467 reference_type = TREE_TYPE (t->type);
5468 reference_type = build_reference_type (reference_type);
5470 if (t->kind == ck_qual)
5472 if (t->kind == ck_ptr)
5474 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5475 t = direct_reference_binding (reference_type, t);
5480 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5481 and return the type to which the reference refers. Otherwise,
5482 leave *ICS unchanged and return NULL_TREE. */
5485 maybe_handle_ref_bind (conversion **ics)
5487 if ((*ics)->kind == ck_ref_bind)
5489 conversion *old_ics = *ics;
5490 tree type = TREE_TYPE (old_ics->type);
5491 *ics = old_ics->u.next;
5492 (*ics)->user_conv_p = old_ics->user_conv_p;
5493 (*ics)->bad_p = old_ics->bad_p;
5500 /* Compare two implicit conversion sequences according to the rules set out in
5501 [over.ics.rank]. Return values:
5503 1: ics1 is better than ics2
5504 -1: ics2 is better than ics1
5505 0: ics1 and ics2 are indistinguishable */
5508 compare_ics (conversion *ics1, conversion *ics2)
5514 tree deref_from_type1 = NULL_TREE;
5515 tree deref_from_type2 = NULL_TREE;
5516 tree deref_to_type1 = NULL_TREE;
5517 tree deref_to_type2 = NULL_TREE;
5518 conversion_rank rank1, rank2;
5520 /* REF_BINDING is nonzero if the result of the conversion sequence
5521 is a reference type. In that case TARGET_TYPE is the
5522 type referred to by the reference. */
5526 /* Handle implicit object parameters. */
5527 maybe_handle_implicit_object (&ics1);
5528 maybe_handle_implicit_object (&ics2);
5530 /* Handle reference parameters. */
5531 target_type1 = maybe_handle_ref_bind (&ics1);
5532 target_type2 = maybe_handle_ref_bind (&ics2);
5536 When comparing the basic forms of implicit conversion sequences (as
5537 defined in _over.best.ics_)
5539 --a standard conversion sequence (_over.ics.scs_) is a better
5540 conversion sequence than a user-defined conversion sequence
5541 or an ellipsis conversion sequence, and
5543 --a user-defined conversion sequence (_over.ics.user_) is a
5544 better conversion sequence than an ellipsis conversion sequence
5545 (_over.ics.ellipsis_). */
5546 rank1 = CONVERSION_RANK (ics1);
5547 rank2 = CONVERSION_RANK (ics2);
5551 else if (rank1 < rank2)
5554 if (rank1 == cr_bad)
5556 /* XXX Isn't this an extension? */
5557 /* Both ICS are bad. We try to make a decision based on what
5558 would have happened if they'd been good. */
5559 if (ics1->user_conv_p > ics2->user_conv_p
5560 || ics1->rank > ics2->rank)
5562 else if (ics1->user_conv_p < ics2->user_conv_p
5563 || ics1->rank < ics2->rank)
5566 /* We couldn't make up our minds; try to figure it out below. */
5569 if (ics1->ellipsis_p)
5570 /* Both conversions are ellipsis conversions. */
5573 /* User-defined conversion sequence U1 is a better conversion sequence
5574 than another user-defined conversion sequence U2 if they contain the
5575 same user-defined conversion operator or constructor and if the sec-
5576 ond standard conversion sequence of U1 is better than the second
5577 standard conversion sequence of U2. */
5579 if (ics1->user_conv_p)
5584 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5585 if (t1->kind == ck_ambig)
5587 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5588 if (t2->kind == ck_ambig)
5591 if (t1->cand->fn != t2->cand->fn)
5594 /* We can just fall through here, after setting up
5595 FROM_TYPE1 and FROM_TYPE2. */
5596 from_type1 = t1->type;
5597 from_type2 = t2->type;
5604 /* We're dealing with two standard conversion sequences.
5608 Standard conversion sequence S1 is a better conversion
5609 sequence than standard conversion sequence S2 if
5611 --S1 is a proper subsequence of S2 (comparing the conversion
5612 sequences in the canonical form defined by _over.ics.scs_,
5613 excluding any Lvalue Transformation; the identity
5614 conversion sequence is considered to be a subsequence of
5615 any non-identity conversion sequence */
5618 while (t1->kind != ck_identity)
5620 from_type1 = t1->type;
5623 while (t2->kind != ck_identity)
5625 from_type2 = t2->type;
5628 if (same_type_p (from_type1, from_type2))
5630 if (is_subseq (ics1, ics2))
5632 if (is_subseq (ics2, ics1))
5635 /* Otherwise, one sequence cannot be a subsequence of the other; they
5636 don't start with the same type. This can happen when comparing the
5637 second standard conversion sequence in two user-defined conversion
5644 --the rank of S1 is better than the rank of S2 (by the rules
5647 Standard conversion sequences are ordered by their ranks: an Exact
5648 Match is a better conversion than a Promotion, which is a better
5649 conversion than a Conversion.
5651 Two conversion sequences with the same rank are indistinguishable
5652 unless one of the following rules applies:
5654 --A conversion that is not a conversion of a pointer, or pointer
5655 to member, to bool is better than another conversion that is such
5658 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5659 so that we do not have to check it explicitly. */
5660 if (ics1->rank < ics2->rank)
5662 else if (ics2->rank < ics1->rank)
5665 to_type1 = ics1->type;
5666 to_type2 = ics2->type;
5668 if (TYPE_PTR_P (from_type1)
5669 && TYPE_PTR_P (from_type2)
5670 && TYPE_PTR_P (to_type1)
5671 && TYPE_PTR_P (to_type2))
5673 deref_from_type1 = TREE_TYPE (from_type1);
5674 deref_from_type2 = TREE_TYPE (from_type2);
5675 deref_to_type1 = TREE_TYPE (to_type1);
5676 deref_to_type2 = TREE_TYPE (to_type2);
5678 /* The rules for pointers to members A::* are just like the rules
5679 for pointers A*, except opposite: if B is derived from A then
5680 A::* converts to B::*, not vice versa. For that reason, we
5681 switch the from_ and to_ variables here. */
5682 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5683 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5684 || (TYPE_PTRMEMFUNC_P (from_type1)
5685 && TYPE_PTRMEMFUNC_P (from_type2)
5686 && TYPE_PTRMEMFUNC_P (to_type1)
5687 && TYPE_PTRMEMFUNC_P (to_type2)))
5689 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5690 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5691 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5692 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5695 if (deref_from_type1 != NULL_TREE
5696 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5697 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5699 /* This was one of the pointer or pointer-like conversions.
5703 --If class B is derived directly or indirectly from class A,
5704 conversion of B* to A* is better than conversion of B* to
5705 void*, and conversion of A* to void* is better than
5706 conversion of B* to void*. */
5707 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5708 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5710 if (is_properly_derived_from (deref_from_type1,
5713 else if (is_properly_derived_from (deref_from_type2,
5717 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
5718 || TREE_CODE (deref_to_type2) == VOID_TYPE)
5720 if (same_type_p (deref_from_type1, deref_from_type2))
5722 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
5724 if (is_properly_derived_from (deref_from_type1,
5728 /* We know that DEREF_TO_TYPE1 is `void' here. */
5729 else if (is_properly_derived_from (deref_from_type1,
5734 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
5735 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
5739 --If class B is derived directly or indirectly from class A
5740 and class C is derived directly or indirectly from B,
5742 --conversion of C* to B* is better than conversion of C* to
5745 --conversion of B* to A* is better than conversion of C* to
5747 if (same_type_p (deref_from_type1, deref_from_type2))
5749 if (is_properly_derived_from (deref_to_type1,
5752 else if (is_properly_derived_from (deref_to_type2,
5756 else if (same_type_p (deref_to_type1, deref_to_type2))
5758 if (is_properly_derived_from (deref_from_type2,
5761 else if (is_properly_derived_from (deref_from_type1,
5767 else if (CLASS_TYPE_P (non_reference (from_type1))
5768 && same_type_p (from_type1, from_type2))
5770 tree from = non_reference (from_type1);
5774 --binding of an expression of type C to a reference of type
5775 B& is better than binding an expression of type C to a
5776 reference of type A&
5778 --conversion of C to B is better than conversion of C to A, */
5779 if (is_properly_derived_from (from, to_type1)
5780 && is_properly_derived_from (from, to_type2))
5782 if (is_properly_derived_from (to_type1, to_type2))
5784 else if (is_properly_derived_from (to_type2, to_type1))
5788 else if (CLASS_TYPE_P (non_reference (to_type1))
5789 && same_type_p (to_type1, to_type2))
5791 tree to = non_reference (to_type1);
5795 --binding of an expression of type B to a reference of type
5796 A& is better than binding an expression of type C to a
5797 reference of type A&,
5799 --conversion of B to A is better than conversion of C to A */
5800 if (is_properly_derived_from (from_type1, to)
5801 && is_properly_derived_from (from_type2, to))
5803 if (is_properly_derived_from (from_type2, from_type1))
5805 else if (is_properly_derived_from (from_type1, from_type2))
5812 --S1 and S2 differ only in their qualification conversion and yield
5813 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
5814 qualification signature of type T1 is a proper subset of the cv-
5815 qualification signature of type T2 */
5816 if (ics1->kind == ck_qual
5817 && ics2->kind == ck_qual
5818 && same_type_p (from_type1, from_type2))
5819 return comp_cv_qual_signature (to_type1, to_type2);
5823 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
5824 types to which the references refer are the same type except for
5825 top-level cv-qualifiers, and the type to which the reference
5826 initialized by S2 refers is more cv-qualified than the type to
5827 which the reference initialized by S1 refers */
5829 if (target_type1 && target_type2
5830 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
5831 return comp_cv_qualification (target_type2, target_type1);
5833 /* Neither conversion sequence is better than the other. */
5837 /* The source type for this standard conversion sequence. */
5840 source_type (conversion *t)
5842 for (;; t = t->u.next)
5844 if (t->kind == ck_user
5845 || t->kind == ck_ambig
5846 || t->kind == ck_identity)
5852 /* Note a warning about preferring WINNER to LOSER. We do this by storing
5853 a pointer to LOSER and re-running joust to produce the warning if WINNER
5854 is actually used. */
5857 add_warning (struct z_candidate *winner, struct z_candidate *loser)
5859 candidate_warning *cw;
5861 cw = conversion_obstack_alloc (sizeof (candidate_warning));
5863 cw->next = winner->warnings;
5864 winner->warnings = cw;
5867 /* Compare two candidates for overloading as described in
5868 [over.match.best]. Return values:
5870 1: cand1 is better than cand2
5871 -1: cand2 is better than cand1
5872 0: cand1 and cand2 are indistinguishable */
5875 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
5878 int off1 = 0, off2 = 0;
5882 /* Candidates that involve bad conversions are always worse than those
5884 if (cand1->viable > cand2->viable)
5886 if (cand1->viable < cand2->viable)
5889 /* If we have two pseudo-candidates for conversions to the same type,
5890 or two candidates for the same function, arbitrarily pick one. */
5891 if (cand1->fn == cand2->fn
5892 && (IS_TYPE_OR_DECL_P (cand1->fn)))
5895 /* a viable function F1
5896 is defined to be a better function than another viable function F2 if
5897 for all arguments i, ICSi(F1) is not a worse conversion sequence than
5898 ICSi(F2), and then */
5900 /* for some argument j, ICSj(F1) is a better conversion sequence than
5903 /* For comparing static and non-static member functions, we ignore
5904 the implicit object parameter of the non-static function. The
5905 standard says to pretend that the static function has an object
5906 parm, but that won't work with operator overloading. */
5907 len = cand1->num_convs;
5908 if (len != cand2->num_convs)
5910 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
5911 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
5913 gcc_assert (static_1 != static_2);
5924 for (i = 0; i < len; ++i)
5926 conversion *t1 = cand1->convs[i + off1];
5927 conversion *t2 = cand2->convs[i + off2];
5928 int comp = compare_ics (t1, t2);
5933 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
5934 == cr_std + cr_promotion)
5935 && t1->kind == ck_std
5936 && t2->kind == ck_std
5937 && TREE_CODE (t1->type) == INTEGER_TYPE
5938 && TREE_CODE (t2->type) == INTEGER_TYPE
5939 && (TYPE_PRECISION (t1->type)
5940 == TYPE_PRECISION (t2->type))
5941 && (TYPE_UNSIGNED (t1->u.next->type)
5942 || (TREE_CODE (t1->u.next->type)
5945 tree type = t1->u.next->type;
5947 struct z_candidate *w, *l;
5949 type1 = t1->type, type2 = t2->type,
5950 w = cand1, l = cand2;
5952 type1 = t2->type, type2 = t1->type,
5953 w = cand2, l = cand1;
5957 warning ("passing %qT chooses %qT over %qT",
5958 type, type1, type2);
5959 warning (" in call to %qD", w->fn);
5965 if (winner && comp != winner)
5974 /* warn about confusing overload resolution for user-defined conversions,
5975 either between a constructor and a conversion op, or between two
5977 if (winner && warn_conversion && cand1->second_conv
5978 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
5979 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
5981 struct z_candidate *w, *l;
5982 bool give_warning = false;
5985 w = cand1, l = cand2;
5987 w = cand2, l = cand1;
5989 /* We don't want to complain about `X::operator T1 ()'
5990 beating `X::operator T2 () const', when T2 is a no less
5991 cv-qualified version of T1. */
5992 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
5993 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
5995 tree t = TREE_TYPE (TREE_TYPE (l->fn));
5996 tree f = TREE_TYPE (TREE_TYPE (w->fn));
5998 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6003 if (!comp_ptr_ttypes (t, f))
6004 give_warning = true;
6007 give_warning = true;
6013 tree source = source_type (w->convs[0]);
6014 if (! DECL_CONSTRUCTOR_P (w->fn))
6015 source = TREE_TYPE (source);
6016 warning ("choosing %qD over %qD", w->fn, l->fn);
6017 warning (" for conversion from %qT to %qT",
6018 source, w->second_conv->type);
6019 warning (" because conversion sequence for the argument is better");
6029 F1 is a non-template function and F2 is a template function
6032 if (!cand1->template_decl && cand2->template_decl)
6034 else if (cand1->template_decl && !cand2->template_decl)
6038 F1 and F2 are template functions and the function template for F1 is
6039 more specialized than the template for F2 according to the partial
6042 if (cand1->template_decl && cand2->template_decl)
6044 winner = more_specialized
6045 (TI_TEMPLATE (cand1->template_decl),
6046 TI_TEMPLATE (cand2->template_decl),
6048 /* Tell the deduction code how many real function arguments
6049 we saw, not counting the implicit 'this' argument. But,
6050 add_function_candidate() suppresses the "this" argument
6053 [temp.func.order]: The presence of unused ellipsis and default
6054 arguments has no effect on the partial ordering of function
6057 - (DECL_NONSTATIC_MEMBER_FUNCTION_P (cand1->fn)
6058 - DECL_CONSTRUCTOR_P (cand1->fn)));
6064 the context is an initialization by user-defined conversion (see
6065 _dcl.init_ and _over.match.user_) and the standard conversion
6066 sequence from the return type of F1 to the destination type (i.e.,
6067 the type of the entity being initialized) is a better conversion
6068 sequence than the standard conversion sequence from the return type
6069 of F2 to the destination type. */
6071 if (cand1->second_conv)
6073 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6078 /* Check whether we can discard a builtin candidate, either because we
6079 have two identical ones or matching builtin and non-builtin candidates.
6081 (Pedantically in the latter case the builtin which matched the user
6082 function should not be added to the overload set, but we spot it here.
6085 ... the builtin candidates include ...
6086 - do not have the same parameter type list as any non-template
6087 non-member candidate. */
6089 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6090 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6092 for (i = 0; i < len; ++i)
6093 if (!same_type_p (cand1->convs[i]->type,
6094 cand2->convs[i]->type))
6096 if (i == cand1->num_convs)
6098 if (cand1->fn == cand2->fn)
6099 /* Two built-in candidates; arbitrarily pick one. */
6101 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6102 /* cand1 is built-in; prefer cand2. */
6105 /* cand2 is built-in; prefer cand1. */
6110 /* If the two functions are the same (this can happen with declarations
6111 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6112 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6113 && equal_functions (cand1->fn, cand2->fn))
6118 /* Extension: If the worst conversion for one candidate is worse than the
6119 worst conversion for the other, take the first. */
6122 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6123 struct z_candidate *w = 0, *l = 0;
6125 for (i = 0; i < len; ++i)
6127 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6128 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6129 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6130 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6133 winner = 1, w = cand1, l = cand2;
6135 winner = -1, w = cand2, l = cand1;
6141 ISO C++ says that these are ambiguous, even \
6142 though the worst conversion for the first is better than \
6143 the worst conversion for the second:");
6144 print_z_candidate (_("candidate 1:"), w);
6145 print_z_candidate (_("candidate 2:"), l);
6153 gcc_assert (!winner);
6157 /* Given a list of candidates for overloading, find the best one, if any.
6158 This algorithm has a worst case of O(2n) (winner is last), and a best
6159 case of O(n/2) (totally ambiguous); much better than a sorting
6162 static struct z_candidate *
6163 tourney (struct z_candidate *candidates)
6165 struct z_candidate *champ = candidates, *challenger;
6167 int champ_compared_to_predecessor = 0;
6169 /* Walk through the list once, comparing each current champ to the next
6170 candidate, knocking out a candidate or two with each comparison. */
6172 for (challenger = champ->next; challenger; )
6174 fate = joust (champ, challenger, 0);
6176 challenger = challenger->next;
6181 champ = challenger->next;
6184 champ_compared_to_predecessor = 0;
6189 champ_compared_to_predecessor = 1;
6192 challenger = champ->next;
6196 /* Make sure the champ is better than all the candidates it hasn't yet
6197 been compared to. */
6199 for (challenger = candidates;
6201 && !(champ_compared_to_predecessor && challenger->next == champ);
6202 challenger = challenger->next)
6204 fate = joust (champ, challenger, 0);
6212 /* Returns nonzero if things of type FROM can be converted to TO. */
6215 can_convert (tree to, tree from)
6217 return can_convert_arg (to, from, NULL_TREE);
6220 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6223 can_convert_arg (tree to, tree from, tree arg)
6229 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6230 p = conversion_obstack_alloc (0);
6232 t = implicit_conversion (to, from, arg, LOOKUP_NORMAL);
6233 ok_p = (t && !t->bad_p);
6235 /* Free all the conversions we allocated. */
6236 obstack_free (&conversion_obstack, p);
6241 /* Like can_convert_arg, but allows dubious conversions as well. */
6244 can_convert_arg_bad (tree to, tree from, tree arg)
6249 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6250 p = conversion_obstack_alloc (0);
6251 /* Try to perform the conversion. */
6252 t = implicit_conversion (to, from, arg, LOOKUP_NORMAL);
6253 /* Free all the conversions we allocated. */
6254 obstack_free (&conversion_obstack, p);
6259 /* Convert EXPR to TYPE. Return the converted expression.
6261 Note that we allow bad conversions here because by the time we get to
6262 this point we are committed to doing the conversion. If we end up
6263 doing a bad conversion, convert_like will complain. */
6266 perform_implicit_conversion (tree type, tree expr)
6271 if (error_operand_p (expr))
6272 return error_mark_node;
6274 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6275 p = conversion_obstack_alloc (0);
6277 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6281 error ("could not convert %qE to %qT", expr, type);
6282 expr = error_mark_node;
6285 expr = convert_like (conv, expr);
6287 /* Free all the conversions we allocated. */
6288 obstack_free (&conversion_obstack, p);
6293 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6294 permitted. If the conversion is valid, the converted expression is
6295 returned. Otherwise, NULL_TREE is returned, except in the case
6296 that TYPE is a class type; in that case, an error is issued. If
6297 C_CAST_P is true, then this direction initialization is taking
6298 place as part of a static_cast being attempted as part of a C-style
6302 perform_direct_initialization_if_possible (tree type,
6309 if (type == error_mark_node || error_operand_p (expr))
6310 return error_mark_node;
6313 If the destination type is a (possibly cv-qualified) class type:
6315 -- If the initialization is direct-initialization ...,
6316 constructors are considered. ... If no constructor applies, or
6317 the overload resolution is ambiguous, the initialization is
6319 if (CLASS_TYPE_P (type))
6321 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6322 build_tree_list (NULL_TREE, expr),
6323 type, LOOKUP_NORMAL);
6324 return build_cplus_new (type, expr);
6327 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6328 p = conversion_obstack_alloc (0);
6330 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6332 if (!conv || conv->bad_p)
6335 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6336 /*issue_conversion_warnings=*/false,
6339 /* Free all the conversions we allocated. */
6340 obstack_free (&conversion_obstack, p);
6345 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6346 is being bound to a temporary. Create and return a new VAR_DECL
6347 with the indicated TYPE; this variable will store the value to
6348 which the reference is bound. */
6351 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6355 /* Create the variable. */
6356 var = build_decl (VAR_DECL, NULL_TREE, type);
6357 DECL_ARTIFICIAL (var) = 1;
6358 TREE_USED (var) = 1;
6360 /* Register the variable. */
6361 if (TREE_STATIC (decl))
6363 /* Namespace-scope or local static; give it a mangled name. */
6366 TREE_STATIC (var) = 1;
6367 name = mangle_ref_init_variable (decl);
6368 DECL_NAME (var) = name;
6369 SET_DECL_ASSEMBLER_NAME (var, name);
6370 var = pushdecl_top_level (var);
6374 /* Create a new cleanup level if necessary. */
6375 maybe_push_cleanup_level (type);
6376 /* Don't push unnamed temps. Do set DECL_CONTEXT, though. */
6377 DECL_CONTEXT (var) = current_function_decl;
6383 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6384 initializing a variable of that TYPE. If DECL is non-NULL, it is
6385 the VAR_DECL being initialized with the EXPR. (In that case, the
6386 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6387 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6388 return, if *CLEANUP is no longer NULL, it will be an expression
6389 that should be pushed as a cleanup after the returned expression
6390 is used to initialize DECL.
6392 Return the converted expression. */
6395 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6400 if (type == error_mark_node || error_operand_p (expr))
6401 return error_mark_node;
6403 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6404 p = conversion_obstack_alloc (0);
6406 conv = reference_binding (type, TREE_TYPE (expr), expr, LOOKUP_NORMAL);
6407 if (!conv || conv->bad_p)
6409 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6410 && !real_lvalue_p (expr))
6411 error ("invalid initialization of non-const reference of "
6412 "type %qT from a temporary of type %qT",
6413 type, TREE_TYPE (expr));
6415 error ("invalid initialization of reference of type "
6416 "%qT from expression of type %qT", type,
6418 return error_mark_node;
6421 /* If DECL is non-NULL, then this special rule applies:
6425 The temporary to which the reference is bound or the temporary
6426 that is the complete object to which the reference is bound
6427 persists for the lifetime of the reference.
6429 The temporaries created during the evaluation of the expression
6430 initializing the reference, except the temporary to which the
6431 reference is bound, are destroyed at the end of the
6432 full-expression in which they are created.
6434 In that case, we store the converted expression into a new
6435 VAR_DECL in a new scope.
6437 However, we want to be careful not to create temporaries when
6438 they are not required. For example, given:
6441 struct D : public B {};
6445 there is no need to copy the return value from "f"; we can just
6446 extend its lifetime. Similarly, given:
6449 struct T { operator S(); };
6453 we can extend the lifetime of the return value of the conversion
6455 gcc_assert (conv->kind == ck_ref_bind);
6459 tree base_conv_type;
6461 /* Skip over the REF_BIND. */
6462 conv = conv->u.next;
6463 /* If the next conversion is a BASE_CONV, skip that too -- but
6464 remember that the conversion was required. */
6465 if (conv->kind == ck_base)
6467 if (conv->check_copy_constructor_p)
6468 check_constructor_callable (TREE_TYPE (expr), expr);
6469 base_conv_type = conv->type;
6470 conv = conv->u.next;
6473 base_conv_type = NULL_TREE;
6474 /* Perform the remainder of the conversion. */
6475 expr = convert_like_real (conv, expr,
6476 /*fn=*/NULL_TREE, /*argnum=*/0,
6478 /*issue_conversion_warnings=*/true,
6479 /*c_cast_p=*/false);
6480 if (!real_lvalue_p (expr))
6485 /* Create the temporary variable. */
6486 type = TREE_TYPE (expr);
6487 var = make_temporary_var_for_ref_to_temp (decl, type);
6488 layout_decl (var, 0);
6489 /* If the rvalue is the result of a function call it will be
6490 a TARGET_EXPR. If it is some other construct (such as a
6491 member access expression where the underlying object is
6492 itself the result of a function call), turn it into a
6493 TARGET_EXPR here. It is important that EXPR be a
6494 TARGET_EXPR below since otherwise the INIT_EXPR will
6495 attempt to make a bitwise copy of EXPR to initialize
6497 if (TREE_CODE (expr) != TARGET_EXPR)
6498 expr = get_target_expr (expr);
6499 /* Create the INIT_EXPR that will initialize the temporary
6501 init = build2 (INIT_EXPR, type, var, expr);
6502 if (at_function_scope_p ())
6504 add_decl_expr (var);
6505 *cleanup = cxx_maybe_build_cleanup (var);
6507 /* We must be careful to destroy the temporary only
6508 after its initialization has taken place. If the
6509 initialization throws an exception, then the
6510 destructor should not be run. We cannot simply
6511 transform INIT into something like:
6513 (INIT, ({ CLEANUP_STMT; }))
6515 because emit_local_var always treats the
6516 initializer as a full-expression. Thus, the
6517 destructor would run too early; it would run at the
6518 end of initializing the reference variable, rather
6519 than at the end of the block enclosing the
6522 The solution is to pass back a cleanup expression
6523 which the caller is responsible for attaching to
6524 the statement tree. */
6528 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6529 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6530 static_aggregates = tree_cons (NULL_TREE, var,
6533 /* Use its address to initialize the reference variable. */
6534 expr = build_address (var);
6536 expr = convert_to_base (expr,
6537 build_pointer_type (base_conv_type),
6538 /*check_access=*/true,
6540 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6543 /* Take the address of EXPR. */
6544 expr = build_unary_op (ADDR_EXPR, expr, 0);
6545 /* If a BASE_CONV was required, perform it now. */
6547 expr = (perform_implicit_conversion
6548 (build_pointer_type (base_conv_type), expr));
6549 expr = build_nop (type, expr);
6552 /* Perform the conversion. */
6553 expr = convert_like (conv, expr);
6555 /* Free all the conversions we allocated. */
6556 obstack_free (&conversion_obstack, p);
6561 #include "gt-cp-call.h"