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 /* The type of the expression resulting from the conversion. */
98 /* The next conversion in the chain. Since the conversions are
99 arranged from outermost to innermost, the NEXT conversion will
100 actually be performed before this conversion. This variant is
101 used only when KIND is neither ck_identity nor ck_ambig. */
103 /* The expression at the beginning of the conversion chain. This
104 variant is used only if KIND is ck_identity or ck_ambig. */
107 /* The function candidate corresponding to this conversion
108 sequence. This field is only used if KIND is ck_user. */
109 struct z_candidate *cand;
112 #define CONVERSION_RANK(NODE) \
113 ((NODE)->bad_p ? cr_bad \
114 : (NODE)->ellipsis_p ? cr_ellipsis \
115 : (NODE)->user_conv_p ? cr_user \
118 static struct obstack conversion_obstack;
119 static bool conversion_obstack_initialized;
121 static struct z_candidate * tourney (struct z_candidate *);
122 static int equal_functions (tree, tree);
123 static int joust (struct z_candidate *, struct z_candidate *, bool);
124 static int compare_ics (conversion *, conversion *);
125 static tree build_over_call (struct z_candidate *, int);
126 static tree build_java_interface_fn_ref (tree, tree);
127 #define convert_like(CONV, EXPR) \
128 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
129 /*issue_conversion_warnings=*/true)
130 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
131 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
132 /*issue_conversion_warnings=*/true)
133 static tree convert_like_real (conversion *, tree, tree, int, int, bool);
134 static void op_error (enum tree_code, enum tree_code, tree, tree,
136 static tree build_object_call (tree, tree);
137 static tree resolve_args (tree);
138 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
139 static void print_z_candidate (const char *, struct z_candidate *);
140 static void print_z_candidates (struct z_candidate *);
141 static tree build_this (tree);
142 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
143 static bool any_strictly_viable (struct z_candidate *);
144 static struct z_candidate *add_template_candidate
145 (struct z_candidate **, tree, tree, tree, tree, tree,
146 tree, tree, int, unification_kind_t);
147 static struct z_candidate *add_template_candidate_real
148 (struct z_candidate **, tree, tree, tree, tree, tree,
149 tree, tree, int, tree, unification_kind_t);
150 static struct z_candidate *add_template_conv_candidate
151 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
152 static void add_builtin_candidates
153 (struct z_candidate **, enum tree_code, enum tree_code,
155 static void add_builtin_candidate
156 (struct z_candidate **, enum tree_code, enum tree_code,
157 tree, tree, tree, tree *, tree *, int);
158 static bool is_complete (tree);
159 static void build_builtin_candidate
160 (struct z_candidate **, tree, tree, tree, tree *, tree *,
162 static struct z_candidate *add_conv_candidate
163 (struct z_candidate **, tree, tree, tree, tree, tree);
164 static struct z_candidate *add_function_candidate
165 (struct z_candidate **, tree, tree, tree, tree, tree, int);
166 static conversion *implicit_conversion (tree, tree, tree, int);
167 static conversion *standard_conversion (tree, tree, tree);
168 static conversion *reference_binding (tree, tree, tree, int);
169 static conversion *build_conv (conversion_kind, tree, conversion *);
170 static bool is_subseq (conversion *, conversion *);
171 static tree maybe_handle_ref_bind (conversion **);
172 static void maybe_handle_implicit_object (conversion **);
173 static struct z_candidate *add_candidate
174 (struct z_candidate **, tree, tree, size_t,
175 conversion **, tree, tree, int);
176 static tree source_type (conversion *);
177 static void add_warning (struct z_candidate *, struct z_candidate *);
178 static bool reference_related_p (tree, tree);
179 static bool reference_compatible_p (tree, tree);
180 static conversion *convert_class_to_reference (tree, tree, tree);
181 static conversion *direct_reference_binding (tree, conversion *);
182 static bool promoted_arithmetic_type_p (tree);
183 static conversion *conditional_conversion (tree, tree);
184 static char *name_as_c_string (tree, tree, bool *);
185 static tree call_builtin_trap (void);
186 static tree prep_operand (tree);
187 static void add_candidates (tree, tree, tree, bool, tree, tree,
188 int, struct z_candidate **);
189 static conversion *merge_conversion_sequences (conversion *, conversion *);
190 static bool magic_varargs_p (tree);
191 static tree build_temp (tree, tree, int, void (**)(const char *, ...));
192 static void check_constructor_callable (tree, tree);
194 /* Returns nonzero iff the destructor name specified in NAME
195 (a BIT_NOT_EXPR) matches BASETYPE. The operand of NAME can take many
199 check_dtor_name (tree basetype, tree name)
201 name = TREE_OPERAND (name, 0);
203 /* Just accept something we've already complained about. */
204 if (name == error_mark_node)
207 if (TREE_CODE (name) == TYPE_DECL)
208 name = TREE_TYPE (name);
209 else if (TYPE_P (name))
211 else if (TREE_CODE (name) == IDENTIFIER_NODE)
213 if ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
214 || (TREE_CODE (basetype) == ENUMERAL_TYPE
215 && name == TYPE_IDENTIFIER (basetype)))
218 name = get_type_value (name);
224 template <class T> struct S { ~S(); };
228 NAME will be a class template. */
229 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
233 if (name && TYPE_MAIN_VARIANT (basetype) == TYPE_MAIN_VARIANT (name))
238 /* We want the address of a function or method. We avoid creating a
239 pointer-to-member function. */
242 build_addr_func (tree function)
244 tree type = TREE_TYPE (function);
246 /* We have to do these by hand to avoid real pointer to member
248 if (TREE_CODE (type) == METHOD_TYPE)
250 if (TREE_CODE (function) == OFFSET_REF)
252 tree object = build_address (TREE_OPERAND (function, 0));
253 return get_member_function_from_ptrfunc (&object,
254 TREE_OPERAND (function, 1));
256 function = build_address (function);
259 function = decay_conversion (function);
264 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
265 POINTER_TYPE to those. Note, pointer to member function types
266 (TYPE_PTRMEMFUNC_P) must be handled by our callers. */
269 build_call (tree function, tree parms)
271 int is_constructor = 0;
278 function = build_addr_func (function);
280 if (TYPE_PTRMEMFUNC_P (TREE_TYPE (function)))
282 sorry ("unable to call pointer to member function here");
283 return error_mark_node;
286 fntype = TREE_TYPE (TREE_TYPE (function));
287 result_type = TREE_TYPE (fntype);
289 if (TREE_CODE (function) == ADDR_EXPR
290 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
291 decl = TREE_OPERAND (function, 0);
295 /* We check both the decl and the type; a function may be known not to
296 throw without being declared throw(). */
297 nothrow = ((decl && TREE_NOTHROW (decl))
298 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
300 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
301 current_function_returns_abnormally = 1;
303 if (decl && TREE_DEPRECATED (decl))
304 warn_deprecated_use (decl);
305 require_complete_eh_spec_types (fntype, decl);
307 if (decl && DECL_CONSTRUCTOR_P (decl))
310 if (decl && ! TREE_USED (decl))
312 /* We invoke build_call directly for several library functions.
313 These may have been declared normally if we're building libgcc,
314 so we can't just check DECL_ARTIFICIAL. */
315 gcc_assert (DECL_ARTIFICIAL (decl)
316 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
321 /* Don't pass empty class objects by value. This is useful
322 for tags in STL, which are used to control overload resolution.
323 We don't need to handle other cases of copying empty classes. */
324 if (! decl || ! DECL_BUILT_IN (decl))
325 for (tmp = parms; tmp; tmp = TREE_CHAIN (tmp))
326 if (is_empty_class (TREE_TYPE (TREE_VALUE (tmp)))
327 && ! TREE_ADDRESSABLE (TREE_TYPE (TREE_VALUE (tmp))))
329 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (TREE_VALUE (tmp)));
330 TREE_VALUE (tmp) = build2 (COMPOUND_EXPR, TREE_TYPE (t),
331 TREE_VALUE (tmp), t);
334 function = build3 (CALL_EXPR, result_type, function, parms, NULL_TREE);
335 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
336 TREE_NOTHROW (function) = nothrow;
341 /* Build something of the form ptr->method (args)
342 or object.method (args). This can also build
343 calls to constructors, and find friends.
345 Member functions always take their class variable
348 INSTANCE is a class instance.
350 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
352 PARMS help to figure out what that NAME really refers to.
354 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
355 down to the real instance type to use for access checking. We need this
356 information to get protected accesses correct.
358 FLAGS is the logical disjunction of zero or more LOOKUP_
359 flags. See cp-tree.h for more info.
361 If this is all OK, calls build_function_call with the resolved
364 This function must also handle being called to perform
365 initialization, promotion/coercion of arguments, and
366 instantiation of default parameters.
368 Note that NAME may refer to an instance variable name. If
369 `operator()()' is defined for the type of that field, then we return
372 /* New overloading code. */
374 typedef struct z_candidate z_candidate;
376 typedef struct candidate_warning candidate_warning;
377 struct candidate_warning {
379 candidate_warning *next;
383 /* The FUNCTION_DECL that will be called if this candidate is
384 selected by overload resolution. */
386 /* The arguments to use when calling this function. */
388 /* The implicit conversion sequences for each of the arguments to
391 /* The number of implicit conversion sequences. */
393 /* If FN is a user-defined conversion, the standard conversion
394 sequence from the type returned by FN to the desired destination
396 conversion *second_conv;
398 /* If FN is a member function, the binfo indicating the path used to
399 qualify the name of FN at the call site. This path is used to
400 determine whether or not FN is accessible if it is selected by
401 overload resolution. The DECL_CONTEXT of FN will always be a
402 (possibly improper) base of this binfo. */
404 /* If FN is a non-static member function, the binfo indicating the
405 subobject to which the `this' pointer should be converted if FN
406 is selected by overload resolution. The type pointed to the by
407 the `this' pointer must correspond to the most derived class
408 indicated by the CONVERSION_PATH. */
409 tree conversion_path;
411 candidate_warning *warnings;
415 /* Returns true iff T is a null pointer constant in the sense of
419 null_ptr_cst_p (tree t)
423 A null pointer constant is an integral constant expression
424 (_expr.const_) rvalue of integer type that evaluates to zero. */
425 if (DECL_INTEGRAL_CONSTANT_VAR_P (t))
426 t = decl_constant_value (t);
428 || (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t)))
433 /* Returns nonzero if PARMLIST consists of only default parms and/or
437 sufficient_parms_p (tree parmlist)
439 for (; parmlist && parmlist != void_list_node;
440 parmlist = TREE_CHAIN (parmlist))
441 if (!TREE_PURPOSE (parmlist))
446 /* Allocate N bytes of memory from the conversion obstack. The memory
447 is zeroed before being returned. */
450 conversion_obstack_alloc (size_t n)
453 if (!conversion_obstack_initialized)
455 gcc_obstack_init (&conversion_obstack);
456 conversion_obstack_initialized = true;
458 p = obstack_alloc (&conversion_obstack, n);
463 /* Dynamically allocate a conversion. */
466 alloc_conversion (conversion_kind kind)
469 c = conversion_obstack_alloc (sizeof (conversion));
474 #ifdef ENABLE_CHECKING
476 /* Make sure that all memory on the conversion obstack has been
480 validate_conversion_obstack (void)
482 if (conversion_obstack_initialized)
483 gcc_assert ((obstack_next_free (&conversion_obstack)
484 == obstack_base (&conversion_obstack)));
487 #endif /* ENABLE_CHECKING */
489 /* Dynamically allocate an array of N conversions. */
492 alloc_conversions (size_t n)
494 return conversion_obstack_alloc (n * sizeof (conversion *));
498 build_conv (conversion_kind code, tree type, conversion *from)
501 conversion_rank rank = CONVERSION_RANK (from);
503 /* We can't use buildl1 here because CODE could be USER_CONV, which
504 takes two arguments. In that case, the caller is responsible for
505 filling in the second argument. */
506 t = alloc_conversion (code);
529 t->user_conv_p = (code == ck_user || from->user_conv_p);
530 t->bad_p = from->bad_p;
534 /* Build a representation of the identity conversion from EXPR to
535 itself. The TYPE should match the the type of EXPR, if EXPR is
539 build_identity_conv (tree type, tree expr)
543 c = alloc_conversion (ck_identity);
550 /* Converting from EXPR to TYPE was ambiguous in the sense that there
551 were multiple user-defined conversions to accomplish the job.
552 Build a conversion that indicates that ambiguity. */
555 build_ambiguous_conv (tree type, tree expr)
559 c = alloc_conversion (ck_ambig);
567 strip_top_quals (tree t)
569 if (TREE_CODE (t) == ARRAY_TYPE)
571 return cp_build_qualified_type (t, 0);
574 /* Returns the standard conversion path (see [conv]) from type FROM to type
575 TO, if any. For proper handling of null pointer constants, you must
576 also pass the expression EXPR to convert from. */
579 standard_conversion (tree to, tree from, tree expr)
581 enum tree_code fcode, tcode;
583 bool fromref = false;
585 to = non_reference (to);
586 if (TREE_CODE (from) == REFERENCE_TYPE)
589 from = TREE_TYPE (from);
591 to = strip_top_quals (to);
592 from = strip_top_quals (from);
594 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
595 && expr && type_unknown_p (expr))
597 expr = instantiate_type (to, expr, tf_conv);
598 if (expr == error_mark_node)
600 from = TREE_TYPE (expr);
603 fcode = TREE_CODE (from);
604 tcode = TREE_CODE (to);
606 conv = build_identity_conv (from, expr);
607 if (fcode == FUNCTION_TYPE)
609 from = build_pointer_type (from);
610 fcode = TREE_CODE (from);
611 conv = build_conv (ck_lvalue, from, conv);
613 else if (fcode == ARRAY_TYPE)
615 from = build_pointer_type (TREE_TYPE (from));
616 fcode = TREE_CODE (from);
617 conv = build_conv (ck_lvalue, from, conv);
619 else if (fromref || (expr && lvalue_p (expr)))
620 conv = build_conv (ck_rvalue, from, conv);
622 /* Allow conversion between `__complex__' data types. */
623 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
625 /* The standard conversion sequence to convert FROM to TO is
626 the standard conversion sequence to perform componentwise
628 conversion *part_conv = standard_conversion
629 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE);
633 conv = build_conv (part_conv->kind, to, conv);
634 conv->rank = part_conv->rank;
642 if (same_type_p (from, to))
645 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
646 && expr && null_ptr_cst_p (expr))
647 conv = build_conv (ck_std, to, conv);
648 else if (tcode == POINTER_TYPE && fcode == POINTER_TYPE
649 && TREE_CODE (TREE_TYPE (to)) == VECTOR_TYPE
650 && TREE_CODE (TREE_TYPE (from)) == VECTOR_TYPE
651 && vector_types_convertible_p (TREE_TYPE (to), TREE_TYPE (from)))
652 conv = build_conv (ck_std, to, conv);
653 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
654 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
656 /* For backwards brain damage compatibility, allow interconversion of
657 pointers and integers with a pedwarn. */
658 conv = build_conv (ck_std, to, conv);
661 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
663 /* For backwards brain damage compatibility, allow interconversion of
664 enums and integers with a pedwarn. */
665 conv = build_conv (ck_std, to, conv);
668 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
669 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
674 if (tcode == POINTER_TYPE
675 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
678 else if (VOID_TYPE_P (TREE_TYPE (to))
679 && !TYPE_PTRMEM_P (from)
680 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
682 from = build_pointer_type
683 (cp_build_qualified_type (void_type_node,
684 cp_type_quals (TREE_TYPE (from))));
685 conv = build_conv (ck_ptr, from, conv);
687 else if (TYPE_PTRMEM_P (from))
689 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
690 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
692 if (DERIVED_FROM_P (fbase, tbase)
693 && (same_type_ignoring_top_level_qualifiers_p
694 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
695 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
697 from = build_ptrmem_type (tbase,
698 TYPE_PTRMEM_POINTED_TO_TYPE (from));
699 conv = build_conv (ck_pmem, from, conv);
701 else if (!same_type_p (fbase, tbase))
704 else if (IS_AGGR_TYPE (TREE_TYPE (from))
705 && IS_AGGR_TYPE (TREE_TYPE (to))
708 An rvalue of type "pointer to cv D," where D is a
709 class type, can be converted to an rvalue of type
710 "pointer to cv B," where B is a base class (clause
711 _class.derived_) of D. If B is an inaccessible
712 (clause _class.access_) or ambiguous
713 (_class.member.lookup_) base class of D, a program
714 that necessitates this conversion is ill-formed. */
715 /* Therefore, we use DERIVED_FROM_P, and not
716 ACCESSIBLY_UNIQUELY_DERIVED_FROM_P, in this test. */
717 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
720 cp_build_qualified_type (TREE_TYPE (to),
721 cp_type_quals (TREE_TYPE (from)));
722 from = build_pointer_type (from);
723 conv = build_conv (ck_ptr, from, conv);
726 if (tcode == POINTER_TYPE)
728 to_pointee = TREE_TYPE (to);
729 from_pointee = TREE_TYPE (from);
733 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
734 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
737 if (same_type_p (from, to))
739 else if (comp_ptr_ttypes (to_pointee, from_pointee))
740 conv = build_conv (ck_qual, to, conv);
741 else if (expr && string_conv_p (to, expr, 0))
742 /* converting from string constant to char *. */
743 conv = build_conv (ck_qual, to, conv);
744 else if (ptr_reasonably_similar (to_pointee, from_pointee))
746 conv = build_conv (ck_ptr, to, conv);
754 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
756 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
757 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
758 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
759 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
761 if (!DERIVED_FROM_P (fbase, tbase)
762 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
763 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
764 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
765 || cp_type_quals (fbase) != cp_type_quals (tbase))
768 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
769 from = build_method_type_directly (from,
771 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
772 from = build_ptrmemfunc_type (build_pointer_type (from));
773 conv = build_conv (ck_pmem, from, conv);
775 else if (tcode == BOOLEAN_TYPE)
779 An rvalue of arithmetic, enumeration, pointer, or pointer to
780 member type can be converted to an rvalue of type bool. */
781 if (ARITHMETIC_TYPE_P (from)
782 || fcode == ENUMERAL_TYPE
783 || fcode == POINTER_TYPE
784 || TYPE_PTR_TO_MEMBER_P (from))
786 conv = build_conv (ck_std, to, conv);
787 if (fcode == POINTER_TYPE
788 || TYPE_PTRMEM_P (from)
789 || (TYPE_PTRMEMFUNC_P (from)
790 && conv->rank < cr_pbool))
791 conv->rank = cr_pbool;
797 /* We don't check for ENUMERAL_TYPE here because there are no standard
798 conversions to enum type. */
799 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
800 || tcode == REAL_TYPE)
802 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
804 conv = build_conv (ck_std, to, conv);
806 /* Give this a better rank if it's a promotion. */
807 if (same_type_p (to, type_promotes_to (from))
808 && conv->u.next->rank <= cr_promotion)
809 conv->rank = cr_promotion;
811 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
812 && vector_types_convertible_p (from, to))
813 return build_conv (ck_std, to, conv);
814 else if (IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
815 && is_properly_derived_from (from, to))
817 if (conv->kind == ck_rvalue)
819 conv = build_conv (ck_base, to, conv);
820 /* The derived-to-base conversion indicates the initialization
821 of a parameter with base type from an object of a derived
822 type. A temporary object is created to hold the result of
824 conv->need_temporary_p = true;
832 /* Returns nonzero if T1 is reference-related to T2. */
835 reference_related_p (tree t1, tree t2)
837 t1 = TYPE_MAIN_VARIANT (t1);
838 t2 = TYPE_MAIN_VARIANT (t2);
842 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
843 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
845 return (same_type_p (t1, t2)
846 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
847 && DERIVED_FROM_P (t1, t2)));
850 /* Returns nonzero if T1 is reference-compatible with T2. */
853 reference_compatible_p (tree t1, tree t2)
857 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
858 reference-related to T2 and cv1 is the same cv-qualification as,
859 or greater cv-qualification than, cv2. */
860 return (reference_related_p (t1, t2)
861 && at_least_as_qualified_p (t1, t2));
864 /* Determine whether or not the EXPR (of class type S) can be
865 converted to T as in [over.match.ref]. */
868 convert_class_to_reference (tree t, tree s, tree expr)
874 struct z_candidate *candidates;
875 struct z_candidate *cand;
878 conversions = lookup_conversions (s);
884 Assuming that "cv1 T" is the underlying type of the reference
885 being initialized, and "cv S" is the type of the initializer
886 expression, with S a class type, the candidate functions are
889 --The conversion functions of S and its base classes are
890 considered. Those that are not hidden within S and yield type
891 "reference to cv2 T2", where "cv1 T" is reference-compatible
892 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
894 The argument list has one argument, which is the initializer
899 /* Conceptually, we should take the address of EXPR and put it in
900 the argument list. Unfortunately, however, that can result in
901 error messages, which we should not issue now because we are just
902 trying to find a conversion operator. Therefore, we use NULL,
903 cast to the appropriate type. */
904 arglist = build_int_cst (build_pointer_type (s), 0);
905 arglist = build_tree_list (NULL_TREE, arglist);
907 reference_type = build_reference_type (t);
911 tree fns = TREE_VALUE (conversions);
913 for (; fns; fns = OVL_NEXT (fns))
915 tree f = OVL_CURRENT (fns);
916 tree t2 = TREE_TYPE (TREE_TYPE (f));
920 /* If this is a template function, try to get an exact
922 if (TREE_CODE (f) == TEMPLATE_DECL)
924 cand = add_template_candidate (&candidates,
930 TREE_PURPOSE (conversions),
936 /* Now, see if the conversion function really returns
937 an lvalue of the appropriate type. From the
938 point of view of unification, simply returning an
939 rvalue of the right type is good enough. */
941 t2 = TREE_TYPE (TREE_TYPE (f));
942 if (TREE_CODE (t2) != REFERENCE_TYPE
943 || !reference_compatible_p (t, TREE_TYPE (t2)))
945 candidates = candidates->next;
950 else if (TREE_CODE (t2) == REFERENCE_TYPE
951 && reference_compatible_p (t, TREE_TYPE (t2)))
952 cand = add_function_candidate (&candidates, f, s, arglist,
954 TREE_PURPOSE (conversions),
959 conversion *identity_conv;
960 /* Build a standard conversion sequence indicating the
961 binding from the reference type returned by the
962 function to the desired REFERENCE_TYPE. */
964 = build_identity_conv (TREE_TYPE (TREE_TYPE
965 (TREE_TYPE (cand->fn))),
968 = (direct_reference_binding
969 (reference_type, identity_conv));
970 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
973 conversions = TREE_CHAIN (conversions);
976 candidates = splice_viable (candidates, pedantic, &any_viable_p);
977 /* If none of the conversion functions worked out, let our caller
982 cand = tourney (candidates);
986 /* Now that we know that this is the function we're going to use fix
987 the dummy first argument. */
988 cand->args = tree_cons (NULL_TREE,
990 TREE_CHAIN (cand->args));
992 /* Build a user-defined conversion sequence representing the
994 conv = build_conv (ck_user,
995 TREE_TYPE (TREE_TYPE (cand->fn)),
996 build_identity_conv (TREE_TYPE (expr), expr));
999 /* Merge it with the standard conversion sequence from the
1000 conversion function's return type to the desired type. */
1001 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1003 if (cand->viable == -1)
1006 return cand->second_conv;
1009 /* A reference of the indicated TYPE is being bound directly to the
1010 expression represented by the implicit conversion sequence CONV.
1011 Return a conversion sequence for this binding. */
1014 direct_reference_binding (tree type, conversion *conv)
1018 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1019 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1021 t = TREE_TYPE (type);
1025 When a parameter of reference type binds directly
1026 (_dcl.init.ref_) to an argument expression, the implicit
1027 conversion sequence is the identity conversion, unless the
1028 argument expression has a type that is a derived class of the
1029 parameter type, in which case the implicit conversion sequence is
1030 a derived-to-base Conversion.
1032 If the parameter binds directly to the result of applying a
1033 conversion function to the argument expression, the implicit
1034 conversion sequence is a user-defined conversion sequence
1035 (_over.ics.user_), with the second standard conversion sequence
1036 either an identity conversion or, if the conversion function
1037 returns an entity of a type that is a derived class of the
1038 parameter type, a derived-to-base conversion. */
1039 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1041 /* Represent the derived-to-base conversion. */
1042 conv = build_conv (ck_base, t, conv);
1043 /* We will actually be binding to the base-class subobject in
1044 the derived class, so we mark this conversion appropriately.
1045 That way, convert_like knows not to generate a temporary. */
1046 conv->need_temporary_p = false;
1048 return build_conv (ck_ref_bind, type, conv);
1051 /* Returns the conversion path from type FROM to reference type TO for
1052 purposes of reference binding. For lvalue binding, either pass a
1053 reference type to FROM or an lvalue expression to EXPR. If the
1054 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1055 the conversion returned. */
1058 reference_binding (tree rto, tree rfrom, tree expr, int flags)
1060 conversion *conv = NULL;
1061 tree to = TREE_TYPE (rto);
1065 cp_lvalue_kind lvalue_p = clk_none;
1067 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1069 expr = instantiate_type (to, expr, tf_none);
1070 if (expr == error_mark_node)
1072 from = TREE_TYPE (expr);
1075 if (TREE_CODE (from) == REFERENCE_TYPE)
1077 /* Anything with reference type is an lvalue. */
1078 lvalue_p = clk_ordinary;
1079 from = TREE_TYPE (from);
1082 lvalue_p = real_lvalue_p (expr);
1084 /* Figure out whether or not the types are reference-related and
1085 reference compatible. We have do do this after stripping
1086 references from FROM. */
1087 related_p = reference_related_p (to, from);
1088 compatible_p = reference_compatible_p (to, from);
1090 if (lvalue_p && compatible_p)
1094 If the initializer expression
1096 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1097 is reference-compatible with "cv2 T2,"
1099 the reference is bound directly to the initializer expression
1101 conv = build_identity_conv (from, expr);
1102 conv = direct_reference_binding (rto, conv);
1103 if ((lvalue_p & clk_bitfield) != 0
1104 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1105 /* For the purposes of overload resolution, we ignore the fact
1106 this expression is a bitfield or packed field. (In particular,
1107 [over.ics.ref] says specifically that a function with a
1108 non-const reference parameter is viable even if the
1109 argument is a bitfield.)
1111 However, when we actually call the function we must create
1112 a temporary to which to bind the reference. If the
1113 reference is volatile, or isn't const, then we cannot make
1114 a temporary, so we just issue an error when the conversion
1116 conv->need_temporary_p = true;
1120 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1124 If the initializer expression
1126 -- has a class type (i.e., T2 is a class type) can be
1127 implicitly converted to an lvalue of type "cv3 T3," where
1128 "cv1 T1" is reference-compatible with "cv3 T3". (this
1129 conversion is selected by enumerating the applicable
1130 conversion functions (_over.match.ref_) and choosing the
1131 best one through overload resolution. (_over.match_).
1133 the reference is bound to the lvalue result of the conversion
1134 in the second case. */
1135 conv = convert_class_to_reference (to, from, expr);
1140 /* From this point on, we conceptually need temporaries, even if we
1141 elide them. Only the cases above are "direct bindings". */
1142 if (flags & LOOKUP_NO_TEMP_BIND)
1147 When a parameter of reference type is not bound directly to an
1148 argument expression, the conversion sequence is the one required
1149 to convert the argument expression to the underlying type of the
1150 reference according to _over.best.ics_. Conceptually, this
1151 conversion sequence corresponds to copy-initializing a temporary
1152 of the underlying type with the argument expression. Any
1153 difference in top-level cv-qualification is subsumed by the
1154 initialization itself and does not constitute a conversion. */
1158 Otherwise, the reference shall be to a non-volatile const type. */
1159 if (!CP_TYPE_CONST_NON_VOLATILE_P (to))
1164 If the initializer expression is an rvalue, with T2 a class type,
1165 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1166 is bound in one of the following ways:
1168 -- The reference is bound to the object represented by the rvalue
1169 or to a sub-object within that object.
1173 We use the first alternative. The implicit conversion sequence
1174 is supposed to be same as we would obtain by generating a
1175 temporary. Fortunately, if the types are reference compatible,
1176 then this is either an identity conversion or the derived-to-base
1177 conversion, just as for direct binding. */
1178 if (CLASS_TYPE_P (from) && compatible_p)
1180 conv = build_identity_conv (from, expr);
1181 conv = direct_reference_binding (rto, conv);
1182 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1183 conv->u.next->check_copy_constructor_p = true;
1189 Otherwise, a temporary of type "cv1 T1" is created and
1190 initialized from the initializer expression using the rules for a
1191 non-reference copy initialization. If T1 is reference-related to
1192 T2, cv1 must be the same cv-qualification as, or greater
1193 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1194 if (related_p && !at_least_as_qualified_p (to, from))
1197 conv = implicit_conversion (to, from, expr, flags);
1201 conv = build_conv (ck_ref_bind, rto, conv);
1202 /* This reference binding, unlike those above, requires the
1203 creation of a temporary. */
1204 conv->need_temporary_p = true;
1209 /* Returns the implicit conversion sequence (see [over.ics]) from type FROM
1210 to type TO. The optional expression EXPR may affect the conversion.
1211 FLAGS are the usual overloading flags. Only LOOKUP_NO_CONVERSION is
1215 implicit_conversion (tree to, tree from, tree expr, int flags)
1219 if (from == error_mark_node || to == error_mark_node
1220 || expr == error_mark_node)
1223 if (TREE_CODE (to) == REFERENCE_TYPE)
1224 conv = reference_binding (to, from, expr, flags);
1226 conv = standard_conversion (to, from, expr);
1231 if (expr != NULL_TREE
1232 && (IS_AGGR_TYPE (from)
1233 || IS_AGGR_TYPE (to))
1234 && (flags & LOOKUP_NO_CONVERSION) == 0)
1236 struct z_candidate *cand;
1238 cand = build_user_type_conversion_1
1239 (to, expr, LOOKUP_ONLYCONVERTING);
1241 conv = cand->second_conv;
1243 /* We used to try to bind a reference to a temporary here, but that
1244 is now handled by the recursive call to this function at the end
1245 of reference_binding. */
1252 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1255 static struct z_candidate *
1256 add_candidate (struct z_candidate **candidates,
1258 size_t num_convs, conversion **convs,
1259 tree access_path, tree conversion_path,
1262 struct z_candidate *cand
1263 = conversion_obstack_alloc (sizeof (struct z_candidate));
1267 cand->convs = convs;
1268 cand->num_convs = num_convs;
1269 cand->access_path = access_path;
1270 cand->conversion_path = conversion_path;
1271 cand->viable = viable;
1272 cand->next = *candidates;
1278 /* Create an overload candidate for the function or method FN called with
1279 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1280 to implicit_conversion.
1282 CTYPE, if non-NULL, is the type we want to pretend this function
1283 comes from for purposes of overload resolution. */
1285 static struct z_candidate *
1286 add_function_candidate (struct z_candidate **candidates,
1287 tree fn, tree ctype, tree arglist,
1288 tree access_path, tree conversion_path,
1291 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1294 tree parmnode, argnode;
1298 /* Built-in functions that haven't been declared don't really
1300 if (DECL_ANTICIPATED (fn))
1303 /* The `this', `in_chrg' and VTT arguments to constructors are not
1304 considered in overload resolution. */
1305 if (DECL_CONSTRUCTOR_P (fn))
1307 parmlist = skip_artificial_parms_for (fn, parmlist);
1308 orig_arglist = arglist;
1309 arglist = skip_artificial_parms_for (fn, arglist);
1312 orig_arglist = arglist;
1314 len = list_length (arglist);
1315 convs = alloc_conversions (len);
1317 /* 13.3.2 - Viable functions [over.match.viable]
1318 First, to be a viable function, a candidate function shall have enough
1319 parameters to agree in number with the arguments in the list.
1321 We need to check this first; otherwise, checking the ICSes might cause
1322 us to produce an ill-formed template instantiation. */
1324 parmnode = parmlist;
1325 for (i = 0; i < len; ++i)
1327 if (parmnode == NULL_TREE || parmnode == void_list_node)
1329 parmnode = TREE_CHAIN (parmnode);
1332 if (i < len && parmnode)
1335 /* Make sure there are default args for the rest of the parms. */
1336 else if (!sufficient_parms_p (parmnode))
1342 /* Second, for F to be a viable function, there shall exist for each
1343 argument an implicit conversion sequence that converts that argument
1344 to the corresponding parameter of F. */
1346 parmnode = parmlist;
1349 for (i = 0; i < len; ++i)
1351 tree arg = TREE_VALUE (argnode);
1352 tree argtype = lvalue_type (arg);
1356 if (parmnode == void_list_node)
1359 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1360 && ! DECL_CONSTRUCTOR_P (fn));
1364 tree parmtype = TREE_VALUE (parmnode);
1366 /* The type of the implicit object parameter ('this') for
1367 overload resolution is not always the same as for the
1368 function itself; conversion functions are considered to
1369 be members of the class being converted, and functions
1370 introduced by a using-declaration are considered to be
1371 members of the class that uses them.
1373 Since build_over_call ignores the ICS for the `this'
1374 parameter, we can just change the parm type. */
1375 if (ctype && is_this)
1378 = build_qualified_type (ctype,
1379 TYPE_QUALS (TREE_TYPE (parmtype)));
1380 parmtype = build_pointer_type (parmtype);
1383 t = implicit_conversion (parmtype, argtype, arg, flags);
1387 t = build_identity_conv (argtype, arg);
1388 t->ellipsis_p = true;
1405 parmnode = TREE_CHAIN (parmnode);
1406 argnode = TREE_CHAIN (argnode);
1410 return add_candidate (candidates, fn, orig_arglist, len, convs,
1411 access_path, conversion_path, viable);
1414 /* Create an overload candidate for the conversion function FN which will
1415 be invoked for expression OBJ, producing a pointer-to-function which
1416 will in turn be called with the argument list ARGLIST, and add it to
1417 CANDIDATES. FLAGS is passed on to implicit_conversion.
1419 Actually, we don't really care about FN; we care about the type it
1420 converts to. There may be multiple conversion functions that will
1421 convert to that type, and we rely on build_user_type_conversion_1 to
1422 choose the best one; so when we create our candidate, we record the type
1423 instead of the function. */
1425 static struct z_candidate *
1426 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1427 tree arglist, tree access_path, tree conversion_path)
1429 tree totype = TREE_TYPE (TREE_TYPE (fn));
1430 int i, len, viable, flags;
1431 tree parmlist, parmnode, argnode;
1434 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1435 parmlist = TREE_TYPE (parmlist);
1436 parmlist = TYPE_ARG_TYPES (parmlist);
1438 len = list_length (arglist) + 1;
1439 convs = alloc_conversions (len);
1440 parmnode = parmlist;
1443 flags = LOOKUP_NORMAL;
1445 /* Don't bother looking up the same type twice. */
1446 if (*candidates && (*candidates)->fn == totype)
1449 for (i = 0; i < len; ++i)
1451 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1452 tree argtype = lvalue_type (arg);
1456 t = implicit_conversion (totype, argtype, arg, flags);
1457 else if (parmnode == void_list_node)
1460 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg, flags);
1463 t = build_identity_conv (argtype, arg);
1464 t->ellipsis_p = true;
1478 parmnode = TREE_CHAIN (parmnode);
1479 argnode = TREE_CHAIN (argnode);
1485 if (!sufficient_parms_p (parmnode))
1488 return add_candidate (candidates, totype, arglist, len, convs,
1489 access_path, conversion_path, viable);
1493 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1494 tree type1, tree type2, tree *args, tree *argtypes,
1506 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1507 convs = alloc_conversions (num_convs);
1509 for (i = 0; i < 2; ++i)
1514 t = implicit_conversion (types[i], argtypes[i], args[i], flags);
1518 /* We need something for printing the candidate. */
1519 t = build_identity_conv (types[i], NULL_TREE);
1526 /* For COND_EXPR we rearranged the arguments; undo that now. */
1529 convs[2] = convs[1];
1530 convs[1] = convs[0];
1531 t = implicit_conversion (boolean_type_node, argtypes[2], args[2], flags);
1538 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1540 /*access_path=*/NULL_TREE,
1541 /*conversion_path=*/NULL_TREE,
1546 is_complete (tree t)
1548 return COMPLETE_TYPE_P (complete_type (t));
1551 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1554 promoted_arithmetic_type_p (tree type)
1558 In this section, the term promoted integral type is used to refer
1559 to those integral types which are preserved by integral promotion
1560 (including e.g. int and long but excluding e.g. char).
1561 Similarly, the term promoted arithmetic type refers to promoted
1562 integral types plus floating types. */
1563 return ((INTEGRAL_TYPE_P (type)
1564 && same_type_p (type_promotes_to (type), type))
1565 || TREE_CODE (type) == REAL_TYPE);
1568 /* Create any builtin operator overload candidates for the operator in
1569 question given the converted operand types TYPE1 and TYPE2. The other
1570 args are passed through from add_builtin_candidates to
1571 build_builtin_candidate.
1573 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1574 If CODE is requires candidates operands of the same type of the kind
1575 of which TYPE1 and TYPE2 are, we add both candidates
1576 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1579 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1580 enum tree_code code2, tree fnname, tree type1,
1581 tree type2, tree *args, tree *argtypes, int flags)
1585 case POSTINCREMENT_EXPR:
1586 case POSTDECREMENT_EXPR:
1587 args[1] = integer_zero_node;
1588 type2 = integer_type_node;
1597 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1598 and VQ is either volatile or empty, there exist candidate operator
1599 functions of the form
1600 VQ T& operator++(VQ T&);
1601 T operator++(VQ T&, int);
1602 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1603 type other than bool, and VQ is either volatile or empty, there exist
1604 candidate operator functions of the form
1605 VQ T& operator--(VQ T&);
1606 T operator--(VQ T&, int);
1607 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1608 complete object type, and VQ is either volatile or empty, there exist
1609 candidate operator functions of the form
1610 T*VQ& operator++(T*VQ&);
1611 T*VQ& operator--(T*VQ&);
1612 T* operator++(T*VQ&, int);
1613 T* operator--(T*VQ&, int); */
1615 case POSTDECREMENT_EXPR:
1616 case PREDECREMENT_EXPR:
1617 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1619 case POSTINCREMENT_EXPR:
1620 case PREINCREMENT_EXPR:
1621 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1623 type1 = build_reference_type (type1);
1628 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1629 exist candidate operator functions of the form
1633 8 For every function type T, there exist candidate operator functions of
1635 T& operator*(T*); */
1638 if (TREE_CODE (type1) == POINTER_TYPE
1639 && (TYPE_PTROB_P (type1)
1640 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1644 /* 9 For every type T, there exist candidate operator functions of the form
1647 10For every promoted arithmetic type T, there exist candidate operator
1648 functions of the form
1652 case CONVERT_EXPR: /* unary + */
1653 if (TREE_CODE (type1) == POINTER_TYPE)
1656 if (ARITHMETIC_TYPE_P (type1))
1660 /* 11For every promoted integral type T, there exist candidate operator
1661 functions of the form
1665 if (INTEGRAL_TYPE_P (type1))
1669 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1670 is the same type as C2 or is a derived class of C2, T is a complete
1671 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1672 there exist candidate operator functions of the form
1673 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1674 where CV12 is the union of CV1 and CV2. */
1677 if (TREE_CODE (type1) == POINTER_TYPE
1678 && TYPE_PTR_TO_MEMBER_P (type2))
1680 tree c1 = TREE_TYPE (type1);
1681 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1683 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1684 && (TYPE_PTRMEMFUNC_P (type2)
1685 || is_complete (TREE_TYPE (TREE_TYPE (type2)))))
1690 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1691 didate operator functions of the form
1696 bool operator<(L, R);
1697 bool operator>(L, R);
1698 bool operator<=(L, R);
1699 bool operator>=(L, R);
1700 bool operator==(L, R);
1701 bool operator!=(L, R);
1702 where LR is the result of the usual arithmetic conversions between
1705 14For every pair of types T and I, where T is a cv-qualified or cv-
1706 unqualified complete object type and I is a promoted integral type,
1707 there exist candidate operator functions of the form
1708 T* operator+(T*, I);
1709 T& operator[](T*, I);
1710 T* operator-(T*, I);
1711 T* operator+(I, T*);
1712 T& operator[](I, T*);
1714 15For every T, where T is a pointer to complete object type, there exist
1715 candidate operator functions of the form112)
1716 ptrdiff_t operator-(T, T);
1718 16For every pointer or enumeration type T, there exist candidate operator
1719 functions of the form
1720 bool operator<(T, T);
1721 bool operator>(T, T);
1722 bool operator<=(T, T);
1723 bool operator>=(T, T);
1724 bool operator==(T, T);
1725 bool operator!=(T, T);
1727 17For every pointer to member type T, there exist candidate operator
1728 functions of the form
1729 bool operator==(T, T);
1730 bool operator!=(T, T); */
1733 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1735 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1737 type2 = ptrdiff_type_node;
1741 case TRUNC_DIV_EXPR:
1742 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1748 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1749 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1751 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1756 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1768 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1770 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1772 if (TREE_CODE (type1) == ENUMERAL_TYPE && TREE_CODE (type2) == ENUMERAL_TYPE)
1774 if (TYPE_PTR_P (type1) && null_ptr_cst_p (args[1]))
1779 if (null_ptr_cst_p (args[0]) && TYPE_PTR_P (type2))
1787 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1790 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1792 type1 = ptrdiff_type_node;
1795 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1797 type2 = ptrdiff_type_node;
1802 /* 18For every pair of promoted integral types L and R, there exist candi-
1803 date operator functions of the form
1810 where LR is the result of the usual arithmetic conversions between
1813 case TRUNC_MOD_EXPR:
1819 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1823 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1824 type, VQ is either volatile or empty, and R is a promoted arithmetic
1825 type, there exist candidate operator functions of the form
1826 VQ L& operator=(VQ L&, R);
1827 VQ L& operator*=(VQ L&, R);
1828 VQ L& operator/=(VQ L&, R);
1829 VQ L& operator+=(VQ L&, R);
1830 VQ L& operator-=(VQ L&, R);
1832 20For every pair T, VQ), where T is any type and VQ is either volatile
1833 or empty, there exist candidate operator functions of the form
1834 T*VQ& operator=(T*VQ&, T*);
1836 21For every pair T, VQ), where T is a pointer to member type and VQ is
1837 either volatile or empty, there exist candidate operator functions of
1839 VQ T& operator=(VQ T&, T);
1841 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1842 unqualified complete object type, VQ is either volatile or empty, and
1843 I is a promoted integral type, there exist candidate operator func-
1845 T*VQ& operator+=(T*VQ&, I);
1846 T*VQ& operator-=(T*VQ&, I);
1848 23For every triple L, VQ, R), where L is an integral or enumeration
1849 type, VQ is either volatile or empty, and R is a promoted integral
1850 type, there exist candidate operator functions of the form
1852 VQ L& operator%=(VQ L&, R);
1853 VQ L& operator<<=(VQ L&, R);
1854 VQ L& operator>>=(VQ L&, R);
1855 VQ L& operator&=(VQ L&, R);
1856 VQ L& operator^=(VQ L&, R);
1857 VQ L& operator|=(VQ L&, R); */
1864 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1866 type2 = ptrdiff_type_node;
1870 case TRUNC_DIV_EXPR:
1871 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1875 case TRUNC_MOD_EXPR:
1881 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1886 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1888 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1889 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1890 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1891 || ((TYPE_PTRMEMFUNC_P (type1)
1892 || TREE_CODE (type1) == POINTER_TYPE)
1893 && null_ptr_cst_p (args[1])))
1903 type1 = build_reference_type (type1);
1909 For every pair of promoted arithmetic types L and R, there
1910 exist candidate operator functions of the form
1912 LR operator?(bool, L, R);
1914 where LR is the result of the usual arithmetic conversions
1915 between types L and R.
1917 For every type T, where T is a pointer or pointer-to-member
1918 type, there exist candidate operator functions of the form T
1919 operator?(bool, T, T); */
1921 if (promoted_arithmetic_type_p (type1)
1922 && promoted_arithmetic_type_p (type2))
1926 /* Otherwise, the types should be pointers. */
1927 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
1928 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
1931 /* We don't check that the two types are the same; the logic
1932 below will actually create two candidates; one in which both
1933 parameter types are TYPE1, and one in which both parameter
1941 /* If we're dealing with two pointer types or two enumeral types,
1942 we need candidates for both of them. */
1943 if (type2 && !same_type_p (type1, type2)
1944 && TREE_CODE (type1) == TREE_CODE (type2)
1945 && (TREE_CODE (type1) == REFERENCE_TYPE
1946 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1947 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1948 || TYPE_PTRMEMFUNC_P (type1)
1949 || IS_AGGR_TYPE (type1)
1950 || TREE_CODE (type1) == ENUMERAL_TYPE))
1952 build_builtin_candidate
1953 (candidates, fnname, type1, type1, args, argtypes, flags);
1954 build_builtin_candidate
1955 (candidates, fnname, type2, type2, args, argtypes, flags);
1959 build_builtin_candidate
1960 (candidates, fnname, type1, type2, args, argtypes, flags);
1964 type_decays_to (tree type)
1966 if (TREE_CODE (type) == ARRAY_TYPE)
1967 return build_pointer_type (TREE_TYPE (type));
1968 if (TREE_CODE (type) == FUNCTION_TYPE)
1969 return build_pointer_type (type);
1973 /* There are three conditions of builtin candidates:
1975 1) bool-taking candidates. These are the same regardless of the input.
1976 2) pointer-pair taking candidates. These are generated for each type
1977 one of the input types converts to.
1978 3) arithmetic candidates. According to the standard, we should generate
1979 all of these, but I'm trying not to...
1981 Here we generate a superset of the possible candidates for this particular
1982 case. That is a subset of the full set the standard defines, plus some
1983 other cases which the standard disallows. add_builtin_candidate will
1984 filter out the invalid set. */
1987 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
1988 enum tree_code code2, tree fnname, tree *args,
1993 tree type, argtypes[3];
1994 /* TYPES[i] is the set of possible builtin-operator parameter types
1995 we will consider for the Ith argument. These are represented as
1996 a TREE_LIST; the TREE_VALUE of each node is the potential
2000 for (i = 0; i < 3; ++i)
2003 argtypes[i] = lvalue_type (args[i]);
2005 argtypes[i] = NULL_TREE;
2010 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2011 and VQ is either volatile or empty, there exist candidate operator
2012 functions of the form
2013 VQ T& operator++(VQ T&); */
2015 case POSTINCREMENT_EXPR:
2016 case PREINCREMENT_EXPR:
2017 case POSTDECREMENT_EXPR:
2018 case PREDECREMENT_EXPR:
2023 /* 24There also exist candidate operator functions of the form
2024 bool operator!(bool);
2025 bool operator&&(bool, bool);
2026 bool operator||(bool, bool); */
2028 case TRUTH_NOT_EXPR:
2029 build_builtin_candidate
2030 (candidates, fnname, boolean_type_node,
2031 NULL_TREE, args, argtypes, flags);
2034 case TRUTH_ORIF_EXPR:
2035 case TRUTH_ANDIF_EXPR:
2036 build_builtin_candidate
2037 (candidates, fnname, boolean_type_node,
2038 boolean_type_node, args, argtypes, flags);
2060 types[0] = types[1] = NULL_TREE;
2062 for (i = 0; i < 2; ++i)
2066 else if (IS_AGGR_TYPE (argtypes[i]))
2070 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2073 convs = lookup_conversions (argtypes[i]);
2075 if (code == COND_EXPR)
2077 if (real_lvalue_p (args[i]))
2078 types[i] = tree_cons
2079 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2081 types[i] = tree_cons
2082 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2088 for (; convs; convs = TREE_CHAIN (convs))
2090 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2093 && (TREE_CODE (type) != REFERENCE_TYPE
2094 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2097 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2098 types[i] = tree_cons (NULL_TREE, type, types[i]);
2100 type = non_reference (type);
2101 if (i != 0 || ! ref1)
2103 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2104 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2105 types[i] = tree_cons (NULL_TREE, type, types[i]);
2106 if (INTEGRAL_TYPE_P (type))
2107 type = type_promotes_to (type);
2110 if (! value_member (type, types[i]))
2111 types[i] = tree_cons (NULL_TREE, type, types[i]);
2116 if (code == COND_EXPR && real_lvalue_p (args[i]))
2117 types[i] = tree_cons
2118 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2119 type = non_reference (argtypes[i]);
2120 if (i != 0 || ! ref1)
2122 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2123 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2124 types[i] = tree_cons (NULL_TREE, type, types[i]);
2125 if (INTEGRAL_TYPE_P (type))
2126 type = type_promotes_to (type);
2128 types[i] = tree_cons (NULL_TREE, type, types[i]);
2132 /* Run through the possible parameter types of both arguments,
2133 creating candidates with those parameter types. */
2134 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2137 for (type = types[1]; type; type = TREE_CHAIN (type))
2138 add_builtin_candidate
2139 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2140 TREE_VALUE (type), args, argtypes, flags);
2142 add_builtin_candidate
2143 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2144 NULL_TREE, args, argtypes, flags);
2151 /* If TMPL can be successfully instantiated as indicated by
2152 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2154 TMPL is the template. EXPLICIT_TARGS are any explicit template
2155 arguments. ARGLIST is the arguments provided at the call-site.
2156 The RETURN_TYPE is the desired type for conversion operators. If
2157 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2158 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2159 add_conv_candidate. */
2161 static struct z_candidate*
2162 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2163 tree ctype, tree explicit_targs, tree arglist,
2164 tree return_type, tree access_path,
2165 tree conversion_path, int flags, tree obj,
2166 unification_kind_t strict)
2168 int ntparms = DECL_NTPARMS (tmpl);
2169 tree targs = make_tree_vec (ntparms);
2170 tree args_without_in_chrg = arglist;
2171 struct z_candidate *cand;
2175 /* We don't do deduction on the in-charge parameter, the VTT
2176 parameter or 'this'. */
2177 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2178 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2180 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2181 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2182 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2183 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2185 i = fn_type_unification (tmpl, explicit_targs, targs,
2186 args_without_in_chrg,
2187 return_type, strict, -1);
2192 fn = instantiate_template (tmpl, targs, tf_none);
2193 if (fn == error_mark_node)
2198 A member function template is never instantiated to perform the
2199 copy of a class object to an object of its class type.
2201 It's a little unclear what this means; the standard explicitly
2202 does allow a template to be used to copy a class. For example,
2207 template <class T> A(const T&);
2210 void g () { A a (f ()); }
2212 the member template will be used to make the copy. The section
2213 quoted above appears in the paragraph that forbids constructors
2214 whose only parameter is (a possibly cv-qualified variant of) the
2215 class type, and a logical interpretation is that the intent was
2216 to forbid the instantiation of member templates which would then
2218 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2220 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2221 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2226 if (obj != NULL_TREE)
2227 /* Aha, this is a conversion function. */
2228 cand = add_conv_candidate (candidates, fn, obj, access_path,
2229 conversion_path, arglist);
2231 cand = add_function_candidate (candidates, fn, ctype,
2232 arglist, access_path,
2233 conversion_path, flags);
2234 if (DECL_TI_TEMPLATE (fn) != tmpl)
2235 /* This situation can occur if a member template of a template
2236 class is specialized. Then, instantiate_template might return
2237 an instantiation of the specialization, in which case the
2238 DECL_TI_TEMPLATE field will point at the original
2239 specialization. For example:
2241 template <class T> struct S { template <class U> void f(U);
2242 template <> void f(int) {}; };
2246 Here, TMPL will be template <class U> S<double>::f(U).
2247 And, instantiate template will give us the specialization
2248 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2249 for this will point at template <class T> template <> S<T>::f(int),
2250 so that we can find the definition. For the purposes of
2251 overload resolution, however, we want the original TMPL. */
2252 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2254 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2260 static struct z_candidate *
2261 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2262 tree explicit_targs, tree arglist, tree return_type,
2263 tree access_path, tree conversion_path, int flags,
2264 unification_kind_t strict)
2267 add_template_candidate_real (candidates, tmpl, ctype,
2268 explicit_targs, arglist, return_type,
2269 access_path, conversion_path,
2270 flags, NULL_TREE, strict);
2274 static struct z_candidate *
2275 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2276 tree obj, tree arglist, tree return_type,
2277 tree access_path, tree conversion_path)
2280 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2281 arglist, return_type, access_path,
2282 conversion_path, 0, obj, DEDUCE_CONV);
2285 /* The CANDS are the set of candidates that were considered for
2286 overload resolution. Return the set of viable candidates. If none
2287 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2288 is true if a candidate should be considered viable only if it is
2291 static struct z_candidate*
2292 splice_viable (struct z_candidate *cands,
2296 struct z_candidate *viable;
2297 struct z_candidate **last_viable;
2298 struct z_candidate **cand;
2301 last_viable = &viable;
2302 *any_viable_p = false;
2307 struct z_candidate *c = *cand;
2308 if (strict_p ? c->viable == 1 : c->viable)
2313 last_viable = &c->next;
2314 *any_viable_p = true;
2320 return viable ? viable : cands;
2324 any_strictly_viable (struct z_candidate *cands)
2326 for (; cands; cands = cands->next)
2327 if (cands->viable == 1)
2333 build_this (tree obj)
2335 /* Fix this to work on non-lvalues. */
2336 return build_unary_op (ADDR_EXPR, obj, 0);
2339 /* Returns true iff functions are equivalent. Equivalent functions are
2340 not '==' only if one is a function-local extern function or if
2341 both are extern "C". */
2344 equal_functions (tree fn1, tree fn2)
2346 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2347 || DECL_EXTERN_C_FUNCTION_P (fn1))
2348 return decls_match (fn1, fn2);
2352 /* Print information about one overload candidate CANDIDATE. MSGSTR
2353 is the text to print before the candidate itself.
2355 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2356 to have been run through gettext by the caller. This wart makes
2357 life simpler in print_z_candidates and for the translators. */
2360 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2362 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2364 if (candidate->num_convs == 3)
2365 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2366 candidate->convs[0]->type,
2367 candidate->convs[1]->type,
2368 candidate->convs[2]->type);
2369 else if (candidate->num_convs == 2)
2370 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2371 candidate->convs[0]->type,
2372 candidate->convs[1]->type);
2374 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2375 candidate->convs[0]->type);
2377 else if (TYPE_P (candidate->fn))
2378 inform ("%s %T <conversion>", msgstr, candidate->fn);
2379 else if (candidate->viable == -1)
2380 inform ("%J%s %+#D <near match>", candidate->fn, msgstr, candidate->fn);
2382 inform ("%J%s %+#D", candidate->fn, msgstr, candidate->fn);
2386 print_z_candidates (struct z_candidate *candidates)
2389 struct z_candidate *cand1;
2390 struct z_candidate **cand2;
2392 /* There may be duplicates in the set of candidates. We put off
2393 checking this condition as long as possible, since we have no way
2394 to eliminate duplicates from a set of functions in less than n^2
2395 time. Now we are about to emit an error message, so it is more
2396 permissible to go slowly. */
2397 for (cand1 = candidates; cand1; cand1 = cand1->next)
2399 tree fn = cand1->fn;
2400 /* Skip builtin candidates and conversion functions. */
2401 if (TREE_CODE (fn) != FUNCTION_DECL)
2403 cand2 = &cand1->next;
2406 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2407 && equal_functions (fn, (*cand2)->fn))
2408 *cand2 = (*cand2)->next;
2410 cand2 = &(*cand2)->next;
2417 str = _("candidates are:");
2418 print_z_candidate (str, candidates);
2419 if (candidates->next)
2421 /* Indent successive candidates by the width of the translation
2422 of the above string. */
2423 size_t len = gcc_gettext_width (str) + 1;
2424 char *spaces = alloca (len);
2425 memset (spaces, ' ', len-1);
2426 spaces[len - 1] = '\0';
2428 candidates = candidates->next;
2431 print_z_candidate (spaces, candidates);
2432 candidates = candidates->next;
2438 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2439 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2440 the result of the conversion function to convert it to the final
2441 desired type. Merge the the two sequences into a single sequence,
2442 and return the merged sequence. */
2445 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2449 gcc_assert (user_seq->kind == ck_user);
2451 /* Find the end of the second conversion sequence. */
2453 while ((*t)->kind != ck_identity)
2454 t = &((*t)->u.next);
2456 /* Replace the identity conversion with the user conversion
2460 /* The entire sequence is a user-conversion sequence. */
2461 std_seq->user_conv_p = true;
2466 /* Returns the best overload candidate to perform the requested
2467 conversion. This function is used for three the overloading situations
2468 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2469 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2470 per [dcl.init.ref], so we ignore temporary bindings. */
2472 static struct z_candidate *
2473 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2475 struct z_candidate *candidates, *cand;
2476 tree fromtype = TREE_TYPE (expr);
2477 tree ctors = NULL_TREE;
2478 tree conv_fns = NULL_TREE;
2479 conversion *conv = NULL;
2480 tree args = NULL_TREE;
2483 /* We represent conversion within a hierarchy using RVALUE_CONV and
2484 BASE_CONV, as specified by [over.best.ics]; these become plain
2485 constructor calls, as specified in [dcl.init]. */
2486 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2487 || !DERIVED_FROM_P (totype, fromtype));
2489 if (IS_AGGR_TYPE (totype))
2490 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2492 if (IS_AGGR_TYPE (fromtype))
2493 conv_fns = lookup_conversions (fromtype);
2496 flags |= LOOKUP_NO_CONVERSION;
2502 ctors = BASELINK_FUNCTIONS (ctors);
2504 t = build_int_cst (build_pointer_type (totype), 0);
2505 args = build_tree_list (NULL_TREE, expr);
2506 /* We should never try to call the abstract or base constructor
2508 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2509 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2510 args = tree_cons (NULL_TREE, t, args);
2512 for (; ctors; ctors = OVL_NEXT (ctors))
2514 tree ctor = OVL_CURRENT (ctors);
2515 if (DECL_NONCONVERTING_P (ctor))
2518 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2519 cand = add_template_candidate (&candidates, ctor, totype,
2520 NULL_TREE, args, NULL_TREE,
2521 TYPE_BINFO (totype),
2522 TYPE_BINFO (totype),
2526 cand = add_function_candidate (&candidates, ctor, totype,
2527 args, TYPE_BINFO (totype),
2528 TYPE_BINFO (totype),
2532 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2536 args = build_tree_list (NULL_TREE, build_this (expr));
2538 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2541 tree conversion_path = TREE_PURPOSE (conv_fns);
2542 int convflags = LOOKUP_NO_CONVERSION;
2544 /* If we are called to convert to a reference type, we are trying to
2545 find an lvalue binding, so don't even consider temporaries. If
2546 we don't find an lvalue binding, the caller will try again to
2547 look for a temporary binding. */
2548 if (TREE_CODE (totype) == REFERENCE_TYPE)
2549 convflags |= LOOKUP_NO_TEMP_BIND;
2551 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2553 tree fn = OVL_CURRENT (fns);
2555 /* [over.match.funcs] For conversion functions, the function
2556 is considered to be a member of the class of the implicit
2557 object argument for the purpose of defining the type of
2558 the implicit object parameter.
2560 So we pass fromtype as CTYPE to add_*_candidate. */
2562 if (TREE_CODE (fn) == TEMPLATE_DECL)
2563 cand = add_template_candidate (&candidates, fn, fromtype,
2566 TYPE_BINFO (fromtype),
2571 cand = add_function_candidate (&candidates, fn, fromtype,
2573 TYPE_BINFO (fromtype),
2580 = implicit_conversion (totype,
2581 TREE_TYPE (TREE_TYPE (cand->fn)),
2584 cand->second_conv = ics;
2588 else if (candidates->viable == 1 && ics->bad_p)
2594 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2598 cand = tourney (candidates);
2601 if (flags & LOOKUP_COMPLAIN)
2603 error ("conversion from %qT to %qT is ambiguous",
2605 print_z_candidates (candidates);
2608 cand = candidates; /* any one will do */
2609 cand->second_conv = build_ambiguous_conv (totype, expr);
2610 cand->second_conv->user_conv_p = true;
2611 if (!any_strictly_viable (candidates))
2612 cand->second_conv->bad_p = true;
2613 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2614 ambiguous conversion is no worse than another user-defined
2620 /* Build the user conversion sequence. */
2623 (DECL_CONSTRUCTOR_P (cand->fn)
2624 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2625 build_identity_conv (TREE_TYPE (expr), expr));
2628 /* Combine it with the second conversion sequence. */
2629 cand->second_conv = merge_conversion_sequences (conv,
2632 if (cand->viable == -1)
2633 cand->second_conv->bad_p = true;
2639 build_user_type_conversion (tree totype, tree expr, int flags)
2641 struct z_candidate *cand
2642 = build_user_type_conversion_1 (totype, expr, flags);
2646 if (cand->second_conv->kind == ck_ambig)
2647 return error_mark_node;
2648 return convert_from_reference (convert_like (cand->second_conv, expr));
2653 /* Do any initial processing on the arguments to a function call. */
2656 resolve_args (tree args)
2659 for (t = args; t; t = TREE_CHAIN (t))
2661 tree arg = TREE_VALUE (t);
2663 if (arg == error_mark_node)
2664 return error_mark_node;
2665 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2667 error ("invalid use of void expression");
2668 return error_mark_node;
2670 arg = convert_from_reference (arg);
2671 TREE_VALUE (t) = arg;
2676 /* Perform overload resolution on FN, which is called with the ARGS.
2678 Return the candidate function selected by overload resolution, or
2679 NULL if the event that overload resolution failed. In the case
2680 that overload resolution fails, *CANDIDATES will be the set of
2681 candidates considered, and ANY_VIABLE_P will be set to true or
2682 false to indicate whether or not any of the candidates were
2685 The ARGS should already have gone through RESOLVE_ARGS before this
2686 function is called. */
2688 static struct z_candidate *
2689 perform_overload_resolution (tree fn,
2691 struct z_candidate **candidates,
2694 struct z_candidate *cand;
2695 tree explicit_targs = NULL_TREE;
2696 int template_only = 0;
2699 *any_viable_p = true;
2701 /* Check FN and ARGS. */
2702 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2703 || TREE_CODE (fn) == TEMPLATE_DECL
2704 || TREE_CODE (fn) == OVERLOAD
2705 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2706 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2708 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2710 explicit_targs = TREE_OPERAND (fn, 1);
2711 fn = TREE_OPERAND (fn, 0);
2715 /* Add the various candidate functions. */
2716 add_candidates (fn, args, explicit_targs, template_only,
2717 /*conversion_path=*/NULL_TREE,
2718 /*access_path=*/NULL_TREE,
2722 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2726 cand = tourney (*candidates);
2730 /* Return an expression for a call to FN (a namespace-scope function,
2731 or a static member function) with the ARGS. */
2734 build_new_function_call (tree fn, tree args)
2736 struct z_candidate *candidates, *cand;
2741 args = resolve_args (args);
2742 if (args == error_mark_node)
2743 return error_mark_node;
2745 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2746 p = conversion_obstack_alloc (0);
2748 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2752 if (!any_viable_p && candidates && ! candidates->next)
2753 return build_function_call (candidates->fn, args);
2754 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2755 fn = TREE_OPERAND (fn, 0);
2757 error ("no matching function for call to %<%D(%A)%>",
2758 DECL_NAME (OVL_CURRENT (fn)), args);
2760 error ("call of overloaded %<%D(%A)%> is ambiguous",
2761 DECL_NAME (OVL_CURRENT (fn)), args);
2763 print_z_candidates (candidates);
2764 result = error_mark_node;
2767 result = build_over_call (cand, LOOKUP_NORMAL);
2769 /* Free all the conversions we allocated. */
2770 obstack_free (&conversion_obstack, p);
2775 /* Build a call to a global operator new. FNNAME is the name of the
2776 operator (either "operator new" or "operator new[]") and ARGS are
2777 the arguments provided. *SIZE points to the total number of bytes
2778 required by the allocation, and is updated if that is changed here.
2779 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2780 function determines that no cookie should be used, after all,
2781 *COOKIE_SIZE is set to NULL_TREE. */
2784 build_operator_new_call (tree fnname, tree args, tree *size, tree *cookie_size)
2787 struct z_candidate *candidates;
2788 struct z_candidate *cand;
2791 args = tree_cons (NULL_TREE, *size, args);
2792 args = resolve_args (args);
2793 if (args == error_mark_node)
2800 If this lookup fails to find the name, or if the allocated type
2801 is not a class type, the allocation function's name is looked
2802 up in the global scope.
2804 we disregard block-scope declarations of "operator new". */
2805 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2807 /* Figure out what function is being called. */
2808 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2810 /* If no suitable function could be found, issue an error message
2815 error ("no matching function for call to %<%D(%A)%>",
2816 DECL_NAME (OVL_CURRENT (fns)), args);
2818 error ("call of overloaded %<%D(%A)%> is ambiguous",
2819 DECL_NAME (OVL_CURRENT (fns)), args);
2821 print_z_candidates (candidates);
2822 return error_mark_node;
2825 /* If a cookie is required, add some extra space. Whether
2826 or not a cookie is required cannot be determined until
2827 after we know which function was called. */
2830 bool use_cookie = true;
2831 if (!abi_version_at_least (2))
2833 tree placement = TREE_CHAIN (args);
2834 /* In G++ 3.2, the check was implemented incorrectly; it
2835 looked at the placement expression, rather than the
2836 type of the function. */
2837 if (placement && !TREE_CHAIN (placement)
2838 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2846 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2847 /* Skip the size_t parameter. */
2848 arg_types = TREE_CHAIN (arg_types);
2849 /* Check the remaining parameters (if any). */
2851 && TREE_CHAIN (arg_types) == void_list_node
2852 && same_type_p (TREE_VALUE (arg_types),
2856 /* If we need a cookie, adjust the number of bytes allocated. */
2859 /* Update the total size. */
2860 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2861 /* Update the argument list to reflect the adjusted size. */
2862 TREE_VALUE (args) = *size;
2865 *cookie_size = NULL_TREE;
2868 /* Build the CALL_EXPR. */
2869 return build_over_call (cand, LOOKUP_NORMAL);
2873 build_object_call (tree obj, tree args)
2875 struct z_candidate *candidates = 0, *cand;
2876 tree fns, convs, mem_args = NULL_TREE;
2877 tree type = TREE_TYPE (obj);
2879 tree result = NULL_TREE;
2882 if (TYPE_PTRMEMFUNC_P (type))
2884 /* It's no good looking for an overloaded operator() on a
2885 pointer-to-member-function. */
2886 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
2887 return error_mark_node;
2890 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
2891 if (fns == error_mark_node)
2892 return error_mark_node;
2894 args = resolve_args (args);
2896 if (args == error_mark_node)
2897 return error_mark_node;
2899 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2900 p = conversion_obstack_alloc (0);
2904 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
2905 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
2907 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
2909 tree fn = OVL_CURRENT (fns);
2910 if (TREE_CODE (fn) == TEMPLATE_DECL)
2911 add_template_candidate (&candidates, fn, base, NULL_TREE,
2912 mem_args, NULL_TREE,
2915 LOOKUP_NORMAL, DEDUCE_CALL);
2917 add_function_candidate
2918 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
2919 TYPE_BINFO (type), LOOKUP_NORMAL);
2923 convs = lookup_conversions (type);
2925 for (; convs; convs = TREE_CHAIN (convs))
2927 tree fns = TREE_VALUE (convs);
2928 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
2930 if ((TREE_CODE (totype) == POINTER_TYPE
2931 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
2932 || (TREE_CODE (totype) == REFERENCE_TYPE
2933 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
2934 || (TREE_CODE (totype) == REFERENCE_TYPE
2935 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
2936 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
2937 for (; fns; fns = OVL_NEXT (fns))
2939 tree fn = OVL_CURRENT (fns);
2940 if (TREE_CODE (fn) == TEMPLATE_DECL)
2941 add_template_conv_candidate
2942 (&candidates, fn, obj, args, totype,
2943 /*access_path=*/NULL_TREE,
2944 /*conversion_path=*/NULL_TREE);
2946 add_conv_candidate (&candidates, fn, obj, args,
2947 /*conversion_path=*/NULL_TREE,
2948 /*access_path=*/NULL_TREE);
2952 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2955 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
2956 print_z_candidates (candidates);
2957 result = error_mark_node;
2961 cand = tourney (candidates);
2964 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
2965 print_z_candidates (candidates);
2966 result = error_mark_node;
2968 /* Since cand->fn will be a type, not a function, for a conversion
2969 function, we must be careful not to unconditionally look at
2971 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
2972 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
2973 result = build_over_call (cand, LOOKUP_NORMAL);
2976 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
2977 result = build_function_call (obj, args);
2981 /* Free all the conversions we allocated. */
2982 obstack_free (&conversion_obstack, p);
2988 op_error (enum tree_code code, enum tree_code code2,
2989 tree arg1, tree arg2, tree arg3, const char *problem)
2993 if (code == MODIFY_EXPR)
2994 opname = assignment_operator_name_info[code2].name;
2996 opname = operator_name_info[code].name;
3001 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3002 problem, arg1, arg2, arg3);
3005 case POSTINCREMENT_EXPR:
3006 case POSTDECREMENT_EXPR:
3007 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3011 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3016 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3021 error ("%s for %<operator%s%> in %<%E %s %E%>",
3022 problem, opname, arg1, opname, arg2);
3024 error ("%s for %<operator%s%> in %<%s%E%>",
3025 problem, opname, opname, arg1);
3030 /* Return the implicit conversion sequence that could be used to
3031 convert E1 to E2 in [expr.cond]. */
3034 conditional_conversion (tree e1, tree e2)
3036 tree t1 = non_reference (TREE_TYPE (e1));
3037 tree t2 = non_reference (TREE_TYPE (e2));
3043 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3044 implicitly converted (clause _conv_) to the type "reference to
3045 T2", subject to the constraint that in the conversion the
3046 reference must bind directly (_dcl.init.ref_) to E1. */
3047 if (real_lvalue_p (e2))
3049 conv = implicit_conversion (build_reference_type (t2),
3052 LOOKUP_NO_TEMP_BIND);
3059 If E1 and E2 have class type, and the underlying class types are
3060 the same or one is a base class of the other: E1 can be converted
3061 to match E2 if the class of T2 is the same type as, or a base
3062 class of, the class of T1, and the cv-qualification of T2 is the
3063 same cv-qualification as, or a greater cv-qualification than, the
3064 cv-qualification of T1. If the conversion is applied, E1 is
3065 changed to an rvalue of type T2 that still refers to the original
3066 source class object (or the appropriate subobject thereof). */
3067 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3068 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3070 if (good_base && at_least_as_qualified_p (t2, t1))
3072 conv = build_identity_conv (t1, e1);
3073 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3074 TYPE_MAIN_VARIANT (t2)))
3075 conv = build_conv (ck_base, t2, conv);
3077 conv = build_conv (ck_rvalue, t2, conv);
3086 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3087 converted to the type that expression E2 would have if E2 were
3088 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3089 return implicit_conversion (t2, t1, e1, LOOKUP_NORMAL);
3092 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3093 arguments to the conditional expression. */
3096 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3100 tree result = NULL_TREE;
3101 tree result_type = NULL_TREE;
3102 bool lvalue_p = true;
3103 struct z_candidate *candidates = 0;
3104 struct z_candidate *cand;
3107 /* As a G++ extension, the second argument to the conditional can be
3108 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3109 c'.) If the second operand is omitted, make sure it is
3110 calculated only once. */
3114 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3116 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3117 if (real_lvalue_p (arg1))
3118 arg2 = arg1 = stabilize_reference (arg1);
3120 arg2 = arg1 = save_expr (arg1);
3125 The first expr ession is implicitly converted to bool (clause
3127 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3129 /* If something has already gone wrong, just pass that fact up the
3131 if (error_operand_p (arg1)
3132 || error_operand_p (arg2)
3133 || error_operand_p (arg3))
3134 return error_mark_node;
3138 If either the second or the third operand has type (possibly
3139 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3140 array-to-pointer (_conv.array_), and function-to-pointer
3141 (_conv.func_) standard conversions are performed on the second
3142 and third operands. */
3143 arg2_type = TREE_TYPE (arg2);
3144 arg3_type = TREE_TYPE (arg3);
3145 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3147 /* Do the conversions. We don't these for `void' type arguments
3148 since it can't have any effect and since decay_conversion
3149 does not handle that case gracefully. */
3150 if (!VOID_TYPE_P (arg2_type))
3151 arg2 = decay_conversion (arg2);
3152 if (!VOID_TYPE_P (arg3_type))
3153 arg3 = decay_conversion (arg3);
3154 arg2_type = TREE_TYPE (arg2);
3155 arg3_type = TREE_TYPE (arg3);
3159 One of the following shall hold:
3161 --The second or the third operand (but not both) is a
3162 throw-expression (_except.throw_); the result is of the
3163 type of the other and is an rvalue.
3165 --Both the second and the third operands have type void; the
3166 result is of type void and is an rvalue.
3168 We must avoid calling force_rvalue for expressions of type
3169 "void" because it will complain that their value is being
3171 if (TREE_CODE (arg2) == THROW_EXPR
3172 && TREE_CODE (arg3) != THROW_EXPR)
3174 if (!VOID_TYPE_P (arg3_type))
3175 arg3 = force_rvalue (arg3);
3176 arg3_type = TREE_TYPE (arg3);
3177 result_type = arg3_type;
3179 else if (TREE_CODE (arg2) != THROW_EXPR
3180 && TREE_CODE (arg3) == THROW_EXPR)
3182 if (!VOID_TYPE_P (arg2_type))
3183 arg2 = force_rvalue (arg2);
3184 arg2_type = TREE_TYPE (arg2);
3185 result_type = arg2_type;
3187 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3188 result_type = void_type_node;
3191 error ("%qE has type %<void%> and is not a throw-expression",
3192 VOID_TYPE_P (arg2_type) ? arg2 : arg3);
3193 return error_mark_node;
3197 goto valid_operands;
3201 Otherwise, if the second and third operand have different types,
3202 and either has (possibly cv-qualified) class type, an attempt is
3203 made to convert each of those operands to the type of the other. */
3204 else if (!same_type_p (arg2_type, arg3_type)
3205 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3210 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3211 p = conversion_obstack_alloc (0);
3213 conv2 = conditional_conversion (arg2, arg3);
3214 conv3 = conditional_conversion (arg3, arg2);
3218 If both can be converted, or one can be converted but the
3219 conversion is ambiguous, the program is ill-formed. If
3220 neither can be converted, the operands are left unchanged and
3221 further checking is performed as described below. If exactly
3222 one conversion is possible, that conversion is applied to the
3223 chosen operand and the converted operand is used in place of
3224 the original operand for the remainder of this section. */
3225 if ((conv2 && !conv2->bad_p
3226 && conv3 && !conv3->bad_p)
3227 || (conv2 && conv2->kind == ck_ambig)
3228 || (conv3 && conv3->kind == ck_ambig))
3230 error ("operands to ?: have different types");
3231 result = error_mark_node;
3233 else if (conv2 && !conv2->bad_p)
3235 arg2 = convert_like (conv2, arg2);
3236 arg2 = convert_from_reference (arg2);
3237 arg2_type = TREE_TYPE (arg2);
3239 else if (conv3 && !conv3->bad_p)
3241 arg3 = convert_like (conv3, arg3);
3242 arg3 = convert_from_reference (arg3);
3243 arg3_type = TREE_TYPE (arg3);
3246 /* Free all the conversions we allocated. */
3247 obstack_free (&conversion_obstack, p);
3252 /* If, after the conversion, both operands have class type,
3253 treat the cv-qualification of both operands as if it were the
3254 union of the cv-qualification of the operands.
3256 The standard is not clear about what to do in this
3257 circumstance. For example, if the first operand has type
3258 "const X" and the second operand has a user-defined
3259 conversion to "volatile X", what is the type of the second
3260 operand after this step? Making it be "const X" (matching
3261 the first operand) seems wrong, as that discards the
3262 qualification without actually performing a copy. Leaving it
3263 as "volatile X" seems wrong as that will result in the
3264 conditional expression failing altogether, even though,
3265 according to this step, the one operand could be converted to
3266 the type of the other. */
3267 if ((conv2 || conv3)
3268 && CLASS_TYPE_P (arg2_type)
3269 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3270 arg2_type = arg3_type =
3271 cp_build_qualified_type (arg2_type,
3272 TYPE_QUALS (arg2_type)
3273 | TYPE_QUALS (arg3_type));
3278 If the second and third operands are lvalues and have the same
3279 type, the result is of that type and is an lvalue. */
3280 if (real_lvalue_p (arg2)
3281 && real_lvalue_p (arg3)
3282 && same_type_p (arg2_type, arg3_type))
3284 result_type = arg2_type;
3285 goto valid_operands;
3290 Otherwise, the result is an rvalue. If the second and third
3291 operand do not have the same type, and either has (possibly
3292 cv-qualified) class type, overload resolution is used to
3293 determine the conversions (if any) to be applied to the operands
3294 (_over.match.oper_, _over.built_). */
3296 if (!same_type_p (arg2_type, arg3_type)
3297 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3303 /* Rearrange the arguments so that add_builtin_candidate only has
3304 to know about two args. In build_builtin_candidates, the
3305 arguments are unscrambled. */
3309 add_builtin_candidates (&candidates,
3312 ansi_opname (COND_EXPR),
3318 If the overload resolution fails, the program is
3320 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3323 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3324 print_z_candidates (candidates);
3325 return error_mark_node;
3327 cand = tourney (candidates);
3330 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3331 print_z_candidates (candidates);
3332 return error_mark_node;
3337 Otherwise, the conversions thus determined are applied, and
3338 the converted operands are used in place of the original
3339 operands for the remainder of this section. */
3340 conv = cand->convs[0];
3341 arg1 = convert_like (conv, arg1);
3342 conv = cand->convs[1];
3343 arg2 = convert_like (conv, arg2);
3344 conv = cand->convs[2];
3345 arg3 = convert_like (conv, arg3);
3350 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3351 and function-to-pointer (_conv.func_) standard conversions are
3352 performed on the second and third operands.
3354 We need to force the lvalue-to-rvalue conversion here for class types,
3355 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3356 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3359 arg2 = force_rvalue (arg2);
3360 if (!CLASS_TYPE_P (arg2_type))
3361 arg2_type = TREE_TYPE (arg2);
3363 arg3 = force_rvalue (arg3);
3364 if (!CLASS_TYPE_P (arg2_type))
3365 arg3_type = TREE_TYPE (arg3);
3367 if (arg2 == error_mark_node || arg3 == error_mark_node)
3368 return error_mark_node;
3372 After those conversions, one of the following shall hold:
3374 --The second and third operands have the same type; the result is of
3376 if (same_type_p (arg2_type, arg3_type))
3377 result_type = arg2_type;
3380 --The second and third operands have arithmetic or enumeration
3381 type; the usual arithmetic conversions are performed to bring
3382 them to a common type, and the result is of that type. */
3383 else if ((ARITHMETIC_TYPE_P (arg2_type)
3384 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3385 && (ARITHMETIC_TYPE_P (arg3_type)
3386 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3388 /* In this case, there is always a common type. */
3389 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3392 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3393 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3394 warning ("enumeral mismatch in conditional expression: `%T' vs `%T'",
3395 arg2_type, arg3_type);
3396 else if (extra_warnings
3397 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3398 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3399 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3400 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3401 warning ("enumeral and non-enumeral type in conditional expression");
3403 arg2 = perform_implicit_conversion (result_type, arg2);
3404 arg3 = perform_implicit_conversion (result_type, arg3);
3408 --The second and third operands have pointer type, or one has
3409 pointer type and the other is a null pointer constant; pointer
3410 conversions (_conv.ptr_) and qualification conversions
3411 (_conv.qual_) are performed to bring them to their composite
3412 pointer type (_expr.rel_). The result is of the composite
3415 --The second and third operands have pointer to member type, or
3416 one has pointer to member type and the other is a null pointer
3417 constant; pointer to member conversions (_conv.mem_) and
3418 qualification conversions (_conv.qual_) are performed to bring
3419 them to a common type, whose cv-qualification shall match the
3420 cv-qualification of either the second or the third operand.
3421 The result is of the common type. */
3422 else if ((null_ptr_cst_p (arg2)
3423 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3424 || (null_ptr_cst_p (arg3)
3425 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3426 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3427 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3428 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3430 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3431 arg3, "conditional expression");
3432 if (result_type == error_mark_node)
3433 return error_mark_node;
3434 arg2 = perform_implicit_conversion (result_type, arg2);
3435 arg3 = perform_implicit_conversion (result_type, arg3);
3440 error ("operands to ?: have different types");
3441 return error_mark_node;
3445 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3447 /* We can't use result_type below, as fold might have returned a
3450 /* Expand both sides into the same slot, hopefully the target of the
3451 ?: expression. We used to check for TARGET_EXPRs here, but now we
3452 sometimes wrap them in NOP_EXPRs so the test would fail. */
3453 if (!lvalue_p && CLASS_TYPE_P (TREE_TYPE (result)))
3454 result = get_target_expr (result);
3456 /* If this expression is an rvalue, but might be mistaken for an
3457 lvalue, we must add a NON_LVALUE_EXPR. */
3458 if (!lvalue_p && real_lvalue_p (result))
3459 result = build1 (NON_LVALUE_EXPR, TREE_TYPE (result), result);
3464 /* OPERAND is an operand to an expression. Perform necessary steps
3465 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3469 prep_operand (tree operand)
3473 operand = convert_from_reference (operand);
3474 if (CLASS_TYPE_P (TREE_TYPE (operand))
3475 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3476 /* Make sure the template type is instantiated now. */
3477 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3483 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3484 OVERLOAD) to the CANDIDATES, returning an updated list of
3485 CANDIDATES. The ARGS are the arguments provided to the call,
3486 without any implicit object parameter. The EXPLICIT_TARGS are
3487 explicit template arguments provided. TEMPLATE_ONLY is true if
3488 only template functions should be considered. CONVERSION_PATH,
3489 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3492 add_candidates (tree fns, tree args,
3493 tree explicit_targs, bool template_only,
3494 tree conversion_path, tree access_path,
3496 struct z_candidate **candidates)
3499 tree non_static_args;
3501 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3502 /* Delay creating the implicit this parameter until it is needed. */
3503 non_static_args = NULL_TREE;
3510 fn = OVL_CURRENT (fns);
3511 /* Figure out which set of arguments to use. */
3512 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3514 /* If this function is a non-static member, prepend the implicit
3515 object parameter. */
3516 if (!non_static_args)
3517 non_static_args = tree_cons (NULL_TREE,
3518 build_this (TREE_VALUE (args)),
3520 fn_args = non_static_args;
3523 /* Otherwise, just use the list of arguments provided. */
3526 if (TREE_CODE (fn) == TEMPLATE_DECL)
3527 add_template_candidate (candidates,
3537 else if (!template_only)
3538 add_function_candidate (candidates,
3545 fns = OVL_NEXT (fns);
3550 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3553 struct z_candidate *candidates = 0, *cand;
3554 tree arglist, fnname;
3556 tree result = NULL_TREE;
3557 bool result_valid_p = false;
3558 enum tree_code code2 = NOP_EXPR;
3564 if (error_operand_p (arg1)
3565 || error_operand_p (arg2)
3566 || error_operand_p (arg3))
3567 return error_mark_node;
3569 if (code == MODIFY_EXPR)
3571 code2 = TREE_CODE (arg3);
3573 fnname = ansi_assopname (code2);
3576 fnname = ansi_opname (code);
3578 arg1 = prep_operand (arg1);
3584 case VEC_DELETE_EXPR:
3586 /* Use build_op_new_call and build_op_delete_call instead. */
3590 return build_object_call (arg1, arg2);
3596 arg2 = prep_operand (arg2);
3597 arg3 = prep_operand (arg3);
3599 if (code == COND_EXPR)
3601 if (arg2 == NULL_TREE
3602 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3603 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3604 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3605 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3608 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3609 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3612 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3613 arg2 = integer_zero_node;
3615 arglist = NULL_TREE;
3617 arglist = tree_cons (NULL_TREE, arg3, arglist);
3619 arglist = tree_cons (NULL_TREE, arg2, arglist);
3620 arglist = tree_cons (NULL_TREE, arg1, arglist);
3622 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3623 p = conversion_obstack_alloc (0);
3625 /* Add namespace-scope operators to the list of functions to
3627 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3628 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3629 flags, &candidates);
3630 /* Add class-member operators to the candidate set. */
3631 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3635 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3636 if (fns == error_mark_node)
3638 result = error_mark_node;
3639 goto user_defined_result_ready;
3642 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3644 BASELINK_BINFO (fns),
3645 TYPE_BINFO (TREE_TYPE (arg1)),
3646 flags, &candidates);
3649 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3650 to know about two args; a builtin candidate will always have a first
3651 parameter of type bool. We'll handle that in
3652 build_builtin_candidate. */
3653 if (code == COND_EXPR)
3663 args[2] = NULL_TREE;
3666 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3672 /* For these, the built-in candidates set is empty
3673 [over.match.oper]/3. We don't want non-strict matches
3674 because exact matches are always possible with built-in
3675 operators. The built-in candidate set for COMPONENT_REF
3676 would be empty too, but since there are no such built-in
3677 operators, we accept non-strict matches for them. */
3682 strict_p = pedantic;
3686 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3691 case POSTINCREMENT_EXPR:
3692 case POSTDECREMENT_EXPR:
3693 /* Look for an `operator++ (int)'. If they didn't have
3694 one, then we fall back to the old way of doing things. */
3695 if (flags & LOOKUP_COMPLAIN)
3696 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3697 "trying prefix operator instead",
3699 operator_name_info[code].name);
3700 if (code == POSTINCREMENT_EXPR)
3701 code = PREINCREMENT_EXPR;
3703 code = PREDECREMENT_EXPR;
3704 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3708 /* The caller will deal with these. */
3713 result_valid_p = true;
3717 if (flags & LOOKUP_COMPLAIN)
3719 op_error (code, code2, arg1, arg2, arg3, "no match");
3720 print_z_candidates (candidates);
3722 result = error_mark_node;
3728 cand = tourney (candidates);
3731 if (flags & LOOKUP_COMPLAIN)
3733 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3734 print_z_candidates (candidates);
3736 result = error_mark_node;
3738 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3741 *overloaded_p = true;
3744 && fnname == ansi_assopname (NOP_EXPR)
3745 && DECL_ARTIFICIAL (cand->fn)
3747 && ! candidates->next->next)
3749 warning ("using synthesized %q#D for copy assignment",
3751 cp_warning_at (" where cfront would use %q#D",
3753 ? candidates->next->fn
3757 result = build_over_call (cand, LOOKUP_NORMAL);
3761 /* Give any warnings we noticed during overload resolution. */
3764 struct candidate_warning *w;
3765 for (w = cand->warnings; w; w = w->next)
3766 joust (cand, w->loser, 1);
3769 /* Check for comparison of different enum types. */
3778 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3779 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3780 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3781 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3783 warning ("comparison between %q#T and %q#T",
3784 TREE_TYPE (arg1), TREE_TYPE (arg2));
3791 /* We need to strip any leading REF_BIND so that bitfields
3792 don't cause errors. This should not remove any important
3793 conversions, because builtins don't apply to class
3794 objects directly. */
3795 conv = cand->convs[0];
3796 if (conv->kind == ck_ref_bind)
3797 conv = conv->u.next;
3798 arg1 = convert_like (conv, arg1);
3801 conv = cand->convs[1];
3802 if (conv->kind == ck_ref_bind)
3803 conv = conv->u.next;
3804 arg2 = convert_like (conv, arg2);
3808 conv = cand->convs[2];
3809 if (conv->kind == ck_ref_bind)
3810 conv = conv->u.next;
3811 arg3 = convert_like (conv, arg3);
3816 user_defined_result_ready:
3818 /* Free all the conversions we allocated. */
3819 obstack_free (&conversion_obstack, p);
3821 if (result || result_valid_p)
3828 return build_modify_expr (arg1, code2, arg2);
3831 return build_indirect_ref (arg1, "unary *");
3836 case TRUNC_DIV_EXPR:
3847 case TRUNC_MOD_EXPR:
3851 case TRUTH_ANDIF_EXPR:
3852 case TRUTH_ORIF_EXPR:
3853 return cp_build_binary_op (code, arg1, arg2);
3858 case TRUTH_NOT_EXPR:
3859 case PREINCREMENT_EXPR:
3860 case POSTINCREMENT_EXPR:
3861 case PREDECREMENT_EXPR:
3862 case POSTDECREMENT_EXPR:
3865 return build_unary_op (code, arg1, candidates != 0);
3868 return build_array_ref (arg1, arg2);
3871 return build_conditional_expr (arg1, arg2, arg3);
3874 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
3876 /* The caller will deal with these. */
3888 /* Build a call to operator delete. This has to be handled very specially,
3889 because the restrictions on what signatures match are different from all
3890 other call instances. For a normal delete, only a delete taking (void *)
3891 or (void *, size_t) is accepted. For a placement delete, only an exact
3892 match with the placement new is accepted.
3894 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
3895 ADDR is the pointer to be deleted.
3896 SIZE is the size of the memory block to be deleted.
3897 GLOBAL_P is true if the delete-expression should not consider
3898 class-specific delete operators.
3899 PLACEMENT is the corresponding placement new call, or NULL_TREE. */
3902 build_op_delete_call (enum tree_code code, tree addr, tree size,
3903 bool global_p, tree placement)
3905 tree fn = NULL_TREE;
3906 tree fns, fnname, argtypes, args, type;
3909 if (addr == error_mark_node)
3910 return error_mark_node;
3912 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
3914 fnname = ansi_opname (code);
3916 if (IS_AGGR_TYPE (type) && !global_p)
3919 If the result of the lookup is ambiguous or inaccessible, or if
3920 the lookup selects a placement deallocation function, the
3921 program is ill-formed.
3923 Therefore, we ask lookup_fnfields to complain about ambiguity. */
3925 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
3926 if (fns == error_mark_node)
3927 return error_mark_node;
3932 if (fns == NULL_TREE)
3933 fns = lookup_name_nonclass (fnname);
3940 /* Find the allocation function that is being called. */
3941 call_expr = placement;
3942 /* Extract the function. */
3943 alloc_fn = get_callee_fndecl (call_expr);
3944 gcc_assert (alloc_fn != NULL_TREE);
3945 /* Then the second parm type. */
3946 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
3947 /* Also the second argument. */
3948 args = TREE_CHAIN (TREE_OPERAND (call_expr, 1));
3952 /* First try it without the size argument. */
3953 argtypes = void_list_node;
3957 /* Strip const and volatile from addr. */
3958 addr = cp_convert (ptr_type_node, addr);
3960 /* We make two tries at finding a matching `operator delete'. On
3961 the first pass, we look for a one-operator (or placement)
3962 operator delete. If we're not doing placement delete, then on
3963 the second pass we look for a two-argument delete. */
3964 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
3966 /* Go through the `operator delete' functions looking for one
3967 with a matching type. */
3968 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
3974 /* The first argument must be "void *". */
3975 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
3976 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
3979 /* On the first pass, check the rest of the arguments. */
3985 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
3993 /* On the second pass, the second argument must be
3996 && same_type_p (TREE_VALUE (t), sizetype)
3997 && TREE_CHAIN (t) == void_list_node)
4001 /* If we found a match, we're done. */
4006 /* If we have a matching function, call it. */
4009 /* Make sure we have the actual function, and not an
4011 fn = OVL_CURRENT (fn);
4013 /* If the FN is a member function, make sure that it is
4015 if (DECL_CLASS_SCOPE_P (fn))
4016 perform_or_defer_access_check (TYPE_BINFO (type), fn);
4019 args = tree_cons (NULL_TREE, addr, args);
4021 args = tree_cons (NULL_TREE, addr,
4022 build_tree_list (NULL_TREE, size));
4026 /* The placement args might not be suitable for overload
4027 resolution at this point, so build the call directly. */
4029 return build_cxx_call (fn, args);
4032 return build_function_call (fn, args);
4035 /* If we are doing placement delete we do nothing if we don't find a
4036 matching op delete. */
4040 error ("no suitable %<operator %s> for %qT",
4041 operator_name_info[(int)code].name, type);
4042 return error_mark_node;
4045 /* If the current scope isn't allowed to access DECL along
4046 BASETYPE_PATH, give an error. The most derived class in
4047 BASETYPE_PATH is the one used to qualify DECL. */
4050 enforce_access (tree basetype_path, tree decl)
4052 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4054 if (!accessible_p (basetype_path, decl))
4056 if (TREE_PRIVATE (decl))
4057 cp_error_at ("%q+#D is private", decl);
4058 else if (TREE_PROTECTED (decl))
4059 cp_error_at ("%q+#D is protected", decl);
4061 cp_error_at ("%q+#D is inaccessible", decl);
4062 error ("within this context");
4069 /* Check that a callable constructor to initialize a temporary of
4070 TYPE from an EXPR exists. */
4073 check_constructor_callable (tree type, tree expr)
4075 build_special_member_call (NULL_TREE,
4076 complete_ctor_identifier,
4077 build_tree_list (NULL_TREE, expr),
4079 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4080 | LOOKUP_CONSTRUCTOR_CALLABLE);
4083 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4084 bitwise or of LOOKUP_* values. If any errors are warnings are
4085 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4086 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4090 build_temp (tree expr, tree type, int flags,
4091 void (**diagnostic_fn)(const char *, ...))
4095 savew = warningcount, savee = errorcount;
4096 expr = build_special_member_call (NULL_TREE,
4097 complete_ctor_identifier,
4098 build_tree_list (NULL_TREE, expr),
4100 if (warningcount > savew)
4101 *diagnostic_fn = warning;
4102 else if (errorcount > savee)
4103 *diagnostic_fn = error;
4105 *diagnostic_fn = NULL;
4110 /* Perform the conversions in CONVS on the expression EXPR. FN and
4111 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4112 indicates the `this' argument of a method. INNER is nonzero when
4113 being called to continue a conversion chain. It is negative when a
4114 reference binding will be applied, positive otherwise. If
4115 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4116 conversions will be emitted if appropriate. */
4119 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4120 int inner, bool issue_conversion_warnings)
4122 tree totype = convs->type;
4123 void (*diagnostic_fn)(const char *, ...);
4126 && convs->kind != ck_user
4127 && convs->kind != ck_ambig
4128 && convs->kind != ck_ref_bind)
4130 conversion *t = convs;
4131 for (; t; t = convs->u.next)
4133 if (t->kind == ck_user || !t->bad_p)
4135 expr = convert_like_real (t, expr, fn, argnum, 1,
4136 /*issue_conversion_warnings=*/false);
4139 else if (t->kind == ck_ambig)
4140 return convert_like_real (t, expr, fn, argnum, 1,
4141 /*issue_conversion_warnings=*/false);
4142 else if (t->kind == ck_identity)
4145 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4147 pedwarn (" initializing argument %P of %qD", argnum, fn);
4148 return cp_convert (totype, expr);
4151 if (issue_conversion_warnings)
4152 expr = dubious_conversion_warnings
4153 (totype, expr, "converting", fn, argnum);
4154 switch (convs->kind)
4158 struct z_candidate *cand = convs->cand;
4159 tree convfn = cand->fn;
4162 if (DECL_CONSTRUCTOR_P (convfn))
4164 tree t = build_int_cst (build_pointer_type (DECL_CONTEXT (convfn)),
4167 args = build_tree_list (NULL_TREE, expr);
4168 /* We should never try to call the abstract or base constructor
4170 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (convfn)
4171 && !DECL_HAS_VTT_PARM_P (convfn));
4172 args = tree_cons (NULL_TREE, t, args);
4175 args = build_this (expr);
4176 expr = build_over_call (cand, LOOKUP_NORMAL);
4178 /* If this is a constructor or a function returning an aggr type,
4179 we need to build up a TARGET_EXPR. */
4180 if (DECL_CONSTRUCTOR_P (convfn))
4181 expr = build_cplus_new (totype, expr);
4183 /* The result of the call is then used to direct-initialize the object
4184 that is the destination of the copy-initialization. [dcl.init]
4186 Note that this step is not reflected in the conversion sequence;
4187 it affects the semantics when we actually perform the
4188 conversion, but is not considered during overload resolution.
4190 If the target is a class, that means call a ctor. */
4191 if (IS_AGGR_TYPE (totype)
4192 && (inner >= 0 || !lvalue_p (expr)))
4196 /* Core issue 84, now a DR, says that we don't
4197 allow UDCs for these args (which deliberately
4198 breaks copy-init of an auto_ptr<Base> from an
4199 auto_ptr<Derived>). */
4200 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4207 (" initializing argument %P of %qD from result of %qD",
4208 argnum, fn, convfn);
4211 (" initializing temporary from result of %qD", convfn);
4213 expr = build_cplus_new (totype, expr);
4218 if (type_unknown_p (expr))
4219 expr = instantiate_type (totype, expr, tf_error | tf_warning);
4220 /* Convert a non-array constant variable to its underlying value, unless we
4221 are about to bind it to a reference, in which case we need to
4222 leave it as an lvalue. */
4224 && TREE_CODE (TREE_TYPE (expr)) != ARRAY_TYPE)
4225 expr = decl_constant_value (expr);
4226 if (convs->check_copy_constructor_p)
4227 check_constructor_callable (totype, expr);
4230 /* Call build_user_type_conversion again for the error. */
4231 return build_user_type_conversion
4232 (totype, convs->u.expr, LOOKUP_NORMAL);
4238 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4239 convs->kind == ck_ref_bind ? -1 : 1,
4240 /*issue_conversion_warnings=*/false);
4241 if (expr == error_mark_node)
4242 return error_mark_node;
4244 switch (convs->kind)
4247 if (! IS_AGGR_TYPE (totype))
4249 /* Else fall through. */
4251 if (convs->kind == ck_base && !convs->need_temporary_p)
4253 /* We are going to bind a reference directly to a base-class
4254 subobject of EXPR. */
4255 if (convs->check_copy_constructor_p)
4256 check_constructor_callable (TREE_TYPE (expr), expr);
4257 /* Build an expression for `*((base*) &expr)'. */
4258 expr = build_unary_op (ADDR_EXPR, expr, 0);
4259 expr = perform_implicit_conversion (build_pointer_type (totype),
4261 expr = build_indirect_ref (expr, "implicit conversion");
4265 /* Copy-initialization where the cv-unqualified version of the source
4266 type is the same class as, or a derived class of, the class of the
4267 destination [is treated as direct-initialization]. [dcl.init] */
4268 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4270 if (diagnostic_fn && fn)
4271 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4272 return build_cplus_new (totype, expr);
4276 tree ref_type = totype;
4278 /* If necessary, create a temporary. */
4279 if (convs->need_temporary_p || !lvalue_p (expr))
4281 tree type = convs->u.next->type;
4283 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
4285 /* If the reference is volatile or non-const, we
4286 cannot create a temporary. */
4287 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4289 if (lvalue & clk_bitfield)
4290 error ("cannot bind bitfield %qE to %qT",
4292 else if (lvalue & clk_packed)
4293 error ("cannot bind packed field %qE to %qT",
4296 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4297 return error_mark_node;
4299 expr = build_target_expr_with_type (expr, type);
4302 /* Take the address of the thing to which we will bind the
4304 expr = build_unary_op (ADDR_EXPR, expr, 1);
4305 if (expr == error_mark_node)
4306 return error_mark_node;
4308 /* Convert it to a pointer to the type referred to by the
4309 reference. This will adjust the pointer if a derived to
4310 base conversion is being performed. */
4311 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4313 /* Convert the pointer to the desired reference type. */
4314 return build_nop (ref_type, expr);
4318 return decay_conversion (expr);
4321 /* Warn about deprecated conversion if appropriate. */
4322 string_conv_p (totype, expr, 1);
4328 return ocp_convert (totype, expr, CONV_IMPLICIT,
4329 LOOKUP_NORMAL|LOOKUP_NO_CONVERSION);
4332 /* Build a call to __builtin_trap. */
4335 call_builtin_trap (void)
4337 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4339 gcc_assert (fn != NULL);
4340 fn = build_call (fn, NULL_TREE);
4344 /* ARG is being passed to a varargs function. Perform any conversions
4345 required. Return the converted value. */
4348 convert_arg_to_ellipsis (tree arg)
4352 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4353 standard conversions are performed. */
4354 arg = decay_conversion (arg);
4357 If the argument has integral or enumeration type that is subject
4358 to the integral promotions (_conv.prom_), or a floating point
4359 type that is subject to the floating point promotion
4360 (_conv.fpprom_), the value of the argument is converted to the
4361 promoted type before the call. */
4362 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4363 && (TYPE_PRECISION (TREE_TYPE (arg))
4364 < TYPE_PRECISION (double_type_node)))
4365 arg = convert_to_real (double_type_node, arg);
4366 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4367 arg = perform_integral_promotions (arg);
4369 arg = require_complete_type (arg);
4371 if (arg != error_mark_node
4372 && !pod_type_p (TREE_TYPE (arg)))
4374 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4375 here and do a bitwise copy, but now cp_expr_size will abort if we
4377 If the call appears in the context of a sizeof expression,
4378 there is no need to emit a warning, since the expression won't be
4379 evaluated. We keep the builtin_trap just as a safety check. */
4380 if (!skip_evaluation)
4381 warning ("cannot pass objects of non-POD type %q#T through %<...%>; "
4382 "call will abort at runtime", TREE_TYPE (arg));
4383 arg = call_builtin_trap ();
4384 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4391 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4394 build_x_va_arg (tree expr, tree type)
4396 if (processing_template_decl)
4397 return build_min (VA_ARG_EXPR, type, expr);
4399 type = complete_type_or_else (type, NULL_TREE);
4401 if (expr == error_mark_node || !type)
4402 return error_mark_node;
4404 if (! pod_type_p (type))
4406 /* Undefined behavior [expr.call] 5.2.2/7. */
4407 warning ("cannot receive objects of non-POD type %q#T' through %<...%>; "
4408 "call will abort at runtime", type);
4409 expr = convert (build_pointer_type (type), null_node);
4410 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4411 call_builtin_trap (), expr);
4412 expr = build_indirect_ref (expr, NULL);
4416 return build_va_arg (expr, type);
4419 /* TYPE has been given to va_arg. Apply the default conversions which
4420 would have happened when passed via ellipsis. Return the promoted
4421 type, or the passed type if there is no change. */
4424 cxx_type_promotes_to (tree type)
4428 /* Perform the array-to-pointer and function-to-pointer
4430 type = type_decays_to (type);
4432 promote = type_promotes_to (type);
4433 if (same_type_p (type, promote))
4439 /* ARG is a default argument expression being passed to a parameter of
4440 the indicated TYPE, which is a parameter to FN. Do any required
4441 conversions. Return the converted value. */
4444 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4446 /* If the ARG is an unparsed default argument expression, the
4447 conversion cannot be performed. */
4448 if (TREE_CODE (arg) == DEFAULT_ARG)
4450 error ("the default argument for parameter %d of %qD has "
4451 "not yet been parsed",
4453 return error_mark_node;
4456 if (fn && DECL_TEMPLATE_INFO (fn))
4457 arg = tsubst_default_argument (fn, type, arg);
4459 arg = break_out_target_exprs (arg);
4461 if (TREE_CODE (arg) == CONSTRUCTOR)
4463 arg = digest_init (type, arg, 0);
4464 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4465 "default argument", fn, parmnum);
4469 /* This could get clobbered by the following call. */
4470 if (TREE_HAS_CONSTRUCTOR (arg))
4471 arg = copy_node (arg);
4473 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4474 "default argument", fn, parmnum);
4475 arg = convert_for_arg_passing (type, arg);
4481 /* Returns the type which will really be used for passing an argument of
4485 type_passed_as (tree type)
4487 /* Pass classes with copy ctors by invisible reference. */
4488 if (TREE_ADDRESSABLE (type))
4490 type = build_reference_type (type);
4491 /* There are no other pointers to this temporary. */
4492 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4494 else if (targetm.calls.promote_prototypes (type)
4495 && INTEGRAL_TYPE_P (type)
4496 && COMPLETE_TYPE_P (type)
4497 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4498 TYPE_SIZE (integer_type_node)))
4499 type = integer_type_node;
4504 /* Actually perform the appropriate conversion. */
4507 convert_for_arg_passing (tree type, tree val)
4509 if (val == error_mark_node)
4511 /* Pass classes with copy ctors by invisible reference. */
4512 else if (TREE_ADDRESSABLE (type))
4513 val = build1 (ADDR_EXPR, build_reference_type (type), val);
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 val = perform_integral_promotions (val);
4523 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4524 which no conversions at all should be done. This is true for some
4525 builtins which don't act like normal functions. */
4528 magic_varargs_p (tree fn)
4530 if (DECL_BUILT_IN (fn))
4531 switch (DECL_FUNCTION_CODE (fn))
4533 case BUILT_IN_CLASSIFY_TYPE:
4534 case BUILT_IN_CONSTANT_P:
4535 case BUILT_IN_NEXT_ARG:
4536 case BUILT_IN_STDARG_START:
4537 case BUILT_IN_VA_START:
4546 /* Subroutine of the various build_*_call functions. Overload resolution
4547 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4548 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4549 bitmask of various LOOKUP_* flags which apply to the call itself. */
4552 build_over_call (struct z_candidate *cand, int flags)
4555 tree args = cand->args;
4556 conversion **convs = cand->convs;
4558 tree converted_args = NULL_TREE;
4559 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4564 /* In a template, there is no need to perform all of the work that
4565 is normally done. We are only interested in the type of the call
4566 expression, i.e., the return type of the function. Any semantic
4567 errors will be deferred until the template is instantiated. */
4568 if (processing_template_decl)
4572 return_type = TREE_TYPE (TREE_TYPE (fn));
4573 expr = build3 (CALL_EXPR, return_type, fn, args, NULL_TREE);
4574 if (TREE_THIS_VOLATILE (fn) && cfun)
4575 current_function_returns_abnormally = 1;
4576 if (!VOID_TYPE_P (return_type))
4577 require_complete_type (return_type);
4578 return convert_from_reference (expr);
4581 /* Give any warnings we noticed during overload resolution. */
4584 struct candidate_warning *w;
4585 for (w = cand->warnings; w; w = w->next)
4586 joust (cand, w->loser, 1);
4589 if (DECL_FUNCTION_MEMBER_P (fn))
4591 /* If FN is a template function, two cases must be considered.
4596 template <class T> void f();
4598 template <class T> struct B {
4602 struct C : A, B<int> {
4604 using B<int>::g; // #2
4607 In case #1 where `A::f' is a member template, DECL_ACCESS is
4608 recorded in the primary template but not in its specialization.
4609 We check access of FN using its primary template.
4611 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4612 because it is a member of class template B, DECL_ACCESS is
4613 recorded in the specialization `B<int>::g'. We cannot use its
4614 primary template because `B<T>::g' and `B<int>::g' may have
4615 different access. */
4616 if (DECL_TEMPLATE_INFO (fn)
4617 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4618 perform_or_defer_access_check (cand->access_path,
4619 DECL_TI_TEMPLATE (fn));
4621 perform_or_defer_access_check (cand->access_path, fn);
4624 if (args && TREE_CODE (args) != TREE_LIST)
4625 args = build_tree_list (NULL_TREE, args);
4628 /* The implicit parameters to a constructor are not considered by overload
4629 resolution, and must be of the proper type. */
4630 if (DECL_CONSTRUCTOR_P (fn))
4632 converted_args = tree_cons (NULL_TREE, TREE_VALUE (arg), converted_args);
4633 arg = TREE_CHAIN (arg);
4634 parm = TREE_CHAIN (parm);
4635 /* We should never try to call the abstract constructor. */
4636 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4638 if (DECL_HAS_VTT_PARM_P (fn))
4640 converted_args = tree_cons
4641 (NULL_TREE, TREE_VALUE (arg), converted_args);
4642 arg = TREE_CHAIN (arg);
4643 parm = TREE_CHAIN (parm);
4646 /* Bypass access control for 'this' parameter. */
4647 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4649 tree parmtype = TREE_VALUE (parm);
4650 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4654 if (convs[i]->bad_p)
4655 pedwarn ("passing `%T' as `this' argument of `%#D' discards qualifiers",
4656 TREE_TYPE (argtype), fn);
4658 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4659 X is called for an object that is not of type X, or of a type
4660 derived from X, the behavior is undefined.
4662 So we can assume that anything passed as 'this' is non-null, and
4663 optimize accordingly. */
4664 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4665 /* Convert to the base in which the function was declared. */
4666 gcc_assert (cand->conversion_path != NULL_TREE);
4667 converted_arg = build_base_path (PLUS_EXPR,
4669 cand->conversion_path,
4671 /* Check that the base class is accessible. */
4672 if (!accessible_base_p (TREE_TYPE (argtype),
4673 BINFO_TYPE (cand->conversion_path)))
4674 error ("%qT is not an accessible base of %qT",
4675 BINFO_TYPE (cand->conversion_path),
4676 TREE_TYPE (argtype));
4677 /* If fn was found by a using declaration, the conversion path
4678 will be to the derived class, not the base declaring fn. We
4679 must convert from derived to base. */
4680 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4681 TREE_TYPE (parmtype), ba_ignore, NULL);
4682 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4685 converted_args = tree_cons (NULL_TREE, converted_arg, converted_args);
4686 parm = TREE_CHAIN (parm);
4687 arg = TREE_CHAIN (arg);
4693 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4695 tree type = TREE_VALUE (parm);
4698 val = convert_like_with_context
4699 (conv, TREE_VALUE (arg), fn, i - is_method);
4701 val = convert_for_arg_passing (type, val);
4702 converted_args = tree_cons (NULL_TREE, val, converted_args);
4705 /* Default arguments */
4706 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
4708 = tree_cons (NULL_TREE,
4709 convert_default_arg (TREE_VALUE (parm),
4710 TREE_PURPOSE (parm),
4715 for (; arg; arg = TREE_CHAIN (arg))
4717 tree a = TREE_VALUE (arg);
4718 if (magic_varargs_p (fn))
4719 /* Do no conversions for magic varargs. */;
4721 a = convert_arg_to_ellipsis (a);
4722 converted_args = tree_cons (NULL_TREE, a, converted_args);
4725 converted_args = nreverse (converted_args);
4727 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
4730 /* Avoid actually calling copy constructors and copy assignment operators,
4733 if (! flag_elide_constructors)
4734 /* Do things the hard way. */;
4735 else if (cand->num_convs == 1 && DECL_COPY_CONSTRUCTOR_P (fn))
4738 arg = skip_artificial_parms_for (fn, converted_args);
4739 arg = TREE_VALUE (arg);
4741 /* Pull out the real argument, disregarding const-correctness. */
4743 while (TREE_CODE (targ) == NOP_EXPR
4744 || TREE_CODE (targ) == NON_LVALUE_EXPR
4745 || TREE_CODE (targ) == CONVERT_EXPR)
4746 targ = TREE_OPERAND (targ, 0);
4747 if (TREE_CODE (targ) == ADDR_EXPR)
4749 targ = TREE_OPERAND (targ, 0);
4750 if (!same_type_ignoring_top_level_qualifiers_p
4751 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
4760 arg = build_indirect_ref (arg, 0);
4762 /* [class.copy]: the copy constructor is implicitly defined even if
4763 the implementation elided its use. */
4764 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
4767 /* If we're creating a temp and we already have one, don't create a
4768 new one. If we're not creating a temp but we get one, use
4769 INIT_EXPR to collapse the temp into our target. Otherwise, if the
4770 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
4771 temp or an INIT_EXPR otherwise. */
4772 if (integer_zerop (TREE_VALUE (args)))
4774 if (TREE_CODE (arg) == TARGET_EXPR)
4776 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4777 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
4779 else if (TREE_CODE (arg) == TARGET_EXPR
4780 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
4782 tree to = stabilize_reference
4783 (build_indirect_ref (TREE_VALUE (args), 0));
4785 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
4789 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
4791 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
4793 tree to = stabilize_reference
4794 (build_indirect_ref (TREE_VALUE (converted_args), 0));
4795 tree type = TREE_TYPE (to);
4796 tree as_base = CLASSTYPE_AS_BASE (type);
4798 arg = TREE_VALUE (TREE_CHAIN (converted_args));
4799 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
4801 arg = build_indirect_ref (arg, 0);
4802 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
4806 /* We must only copy the non-tail padding parts.
4807 Use __builtin_memcpy for the bitwise copy. */
4811 args = tree_cons (NULL, TYPE_SIZE_UNIT (as_base), NULL);
4812 args = tree_cons (NULL, arg, args);
4813 t = build_unary_op (ADDR_EXPR, to, 0);
4814 args = tree_cons (NULL, t, args);
4815 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
4816 t = build_call (t, args);
4818 t = convert (TREE_TYPE (TREE_VALUE (args)), t);
4819 val = build_indirect_ref (t, 0);
4827 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
4829 tree t, *p = &TREE_VALUE (converted_args);
4830 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (*p)),
4833 gcc_assert (binfo && binfo != error_mark_node);
4835 *p = build_base_path (PLUS_EXPR, *p, binfo, 1);
4836 if (TREE_SIDE_EFFECTS (*p))
4837 *p = save_expr (*p);
4838 t = build_pointer_type (TREE_TYPE (fn));
4839 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
4840 fn = build_java_interface_fn_ref (fn, *p);
4842 fn = build_vfn_ref (*p, DECL_VINDEX (fn));
4845 else if (DECL_INLINE (fn))
4846 fn = inline_conversion (fn);
4848 fn = build_addr_func (fn);
4850 return build_cxx_call (fn, converted_args);
4853 /* Build and return a call to FN, using ARGS. This function performs
4854 no overload resolution, conversion, or other high-level
4858 build_cxx_call (tree fn, tree args)
4862 fn = build_call (fn, args);
4864 /* If this call might throw an exception, note that fact. */
4865 fndecl = get_callee_fndecl (fn);
4866 if ((!fndecl || !TREE_NOTHROW (fndecl))
4867 && at_function_scope_p ()
4869 cp_function_chain->can_throw = 1;
4871 /* Some built-in function calls will be evaluated at compile-time in
4873 fn = fold_if_not_in_template (fn);
4875 if (VOID_TYPE_P (TREE_TYPE (fn)))
4878 fn = require_complete_type (fn);
4879 if (fn == error_mark_node)
4880 return error_mark_node;
4882 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
4883 fn = build_cplus_new (TREE_TYPE (fn), fn);
4884 return convert_from_reference (fn);
4887 static GTY(()) tree java_iface_lookup_fn;
4889 /* Make an expression which yields the address of the Java interface
4890 method FN. This is achieved by generating a call to libjava's
4891 _Jv_LookupInterfaceMethodIdx(). */
4894 build_java_interface_fn_ref (tree fn, tree instance)
4896 tree lookup_args, lookup_fn, method, idx;
4897 tree klass_ref, iface, iface_ref;
4900 if (!java_iface_lookup_fn)
4902 tree endlink = build_void_list_node ();
4903 tree t = tree_cons (NULL_TREE, ptr_type_node,
4904 tree_cons (NULL_TREE, ptr_type_node,
4905 tree_cons (NULL_TREE, java_int_type_node,
4907 java_iface_lookup_fn
4908 = builtin_function ("_Jv_LookupInterfaceMethodIdx",
4909 build_function_type (ptr_type_node, t),
4910 0, NOT_BUILT_IN, NULL, NULL_TREE);
4913 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
4914 This is the first entry in the vtable. */
4915 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
4918 /* Get the java.lang.Class pointer for the interface being called. */
4919 iface = DECL_CONTEXT (fn);
4920 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
4921 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
4922 || DECL_CONTEXT (iface_ref) != iface)
4924 error ("could not find class$ field in java interface type %qT",
4926 return error_mark_node;
4928 iface_ref = build_address (iface_ref);
4929 iface_ref = convert (build_pointer_type (iface), iface_ref);
4931 /* Determine the itable index of FN. */
4933 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
4935 if (!DECL_VIRTUAL_P (method))
4941 idx = build_int_cst (NULL_TREE, i);
4943 lookup_args = tree_cons (NULL_TREE, klass_ref,
4944 tree_cons (NULL_TREE, iface_ref,
4945 build_tree_list (NULL_TREE, idx)));
4946 lookup_fn = build1 (ADDR_EXPR,
4947 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
4948 java_iface_lookup_fn);
4949 return build3 (CALL_EXPR, ptr_type_node, lookup_fn, lookup_args, NULL_TREE);
4952 /* Returns the value to use for the in-charge parameter when making a
4953 call to a function with the indicated NAME.
4955 FIXME:Can't we find a neater way to do this mapping? */
4958 in_charge_arg_for_name (tree name)
4960 if (name == base_ctor_identifier
4961 || name == base_dtor_identifier)
4962 return integer_zero_node;
4963 else if (name == complete_ctor_identifier)
4964 return integer_one_node;
4965 else if (name == complete_dtor_identifier)
4966 return integer_two_node;
4967 else if (name == deleting_dtor_identifier)
4968 return integer_three_node;
4970 /* This function should only be called with one of the names listed
4976 /* Build a call to a constructor, destructor, or an assignment
4977 operator for INSTANCE, an expression with class type. NAME
4978 indicates the special member function to call; ARGS are the
4979 arguments. BINFO indicates the base of INSTANCE that is to be
4980 passed as the `this' parameter to the member function called.
4982 FLAGS are the LOOKUP_* flags to use when processing the call.
4984 If NAME indicates a complete object constructor, INSTANCE may be
4985 NULL_TREE. In this case, the caller will call build_cplus_new to
4986 store the newly constructed object into a VAR_DECL. */
4989 build_special_member_call (tree instance, tree name, tree args,
4990 tree binfo, int flags)
4993 /* The type of the subobject to be constructed or destroyed. */
4996 gcc_assert (name == complete_ctor_identifier
4997 || name == base_ctor_identifier
4998 || name == complete_dtor_identifier
4999 || name == base_dtor_identifier
5000 || name == deleting_dtor_identifier
5001 || name == ansi_assopname (NOP_EXPR));
5004 /* Resolve the name. */
5005 if (!complete_type_or_else (binfo, NULL_TREE))
5006 return error_mark_node;
5008 binfo = TYPE_BINFO (binfo);
5011 gcc_assert (binfo != NULL_TREE);
5013 class_type = BINFO_TYPE (binfo);
5015 /* Handle the special case where INSTANCE is NULL_TREE. */
5016 if (name == complete_ctor_identifier && !instance)
5018 instance = build_int_cst (build_pointer_type (class_type), 0);
5019 instance = build1 (INDIRECT_REF, class_type, instance);
5023 if (name == complete_dtor_identifier
5024 || name == base_dtor_identifier
5025 || name == deleting_dtor_identifier)
5026 gcc_assert (args == NULL_TREE);
5028 /* Convert to the base class, if necessary. */
5029 if (!same_type_ignoring_top_level_qualifiers_p
5030 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5032 if (name != ansi_assopname (NOP_EXPR))
5033 /* For constructors and destructors, either the base is
5034 non-virtual, or it is virtual but we are doing the
5035 conversion from a constructor or destructor for the
5036 complete object. In either case, we can convert
5038 instance = convert_to_base_statically (instance, binfo);
5040 /* However, for assignment operators, we must convert
5041 dynamically if the base is virtual. */
5042 instance = build_base_path (PLUS_EXPR, instance,
5043 binfo, /*nonnull=*/1);
5047 gcc_assert (instance != NULL_TREE);
5049 fns = lookup_fnfields (binfo, name, 1);
5051 /* When making a call to a constructor or destructor for a subobject
5052 that uses virtual base classes, pass down a pointer to a VTT for
5054 if ((name == base_ctor_identifier
5055 || name == base_dtor_identifier)
5056 && CLASSTYPE_VBASECLASSES (class_type))
5061 /* If the current function is a complete object constructor
5062 or destructor, then we fetch the VTT directly.
5063 Otherwise, we look it up using the VTT we were given. */
5064 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5065 vtt = decay_conversion (vtt);
5066 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5067 build2 (EQ_EXPR, boolean_type_node,
5068 current_in_charge_parm, integer_zero_node),
5071 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5072 sub_vtt = build2 (PLUS_EXPR, TREE_TYPE (vtt), vtt,
5073 BINFO_SUBVTT_INDEX (binfo));
5075 args = tree_cons (NULL_TREE, sub_vtt, args);
5078 return build_new_method_call (instance, fns, args,
5079 TYPE_BINFO (BINFO_TYPE (binfo)),
5083 /* Return the NAME, as a C string. The NAME indicates a function that
5084 is a member of TYPE. *FREE_P is set to true if the caller must
5085 free the memory returned.
5087 Rather than go through all of this, we should simply set the names
5088 of constructors and destructors appropriately, and dispense with
5089 ctor_identifier, dtor_identifier, etc. */
5092 name_as_c_string (tree name, tree type, bool *free_p)
5096 /* Assume that we will not allocate memory. */
5098 /* Constructors and destructors are special. */
5099 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5102 = (char *) IDENTIFIER_POINTER (constructor_name (type));
5103 /* For a destructor, add the '~'. */
5104 if (name == complete_dtor_identifier
5105 || name == base_dtor_identifier
5106 || name == deleting_dtor_identifier)
5108 pretty_name = concat ("~", pretty_name, NULL);
5109 /* Remember that we need to free the memory allocated. */
5113 else if (IDENTIFIER_TYPENAME_P (name))
5115 pretty_name = concat ("operator ",
5116 type_as_string (TREE_TYPE (name),
5117 TFF_PLAIN_IDENTIFIER),
5119 /* Remember that we need to free the memory allocated. */
5123 pretty_name = (char *) IDENTIFIER_POINTER (name);
5128 /* Build a call to "INSTANCE.FN (ARGS)". */
5131 build_new_method_call (tree instance, tree fns, tree args,
5132 tree conversion_path, int flags)
5134 struct z_candidate *candidates = 0, *cand;
5135 tree explicit_targs = NULL_TREE;
5136 tree basetype = NULL_TREE;
5139 tree mem_args = NULL_TREE, instance_ptr;
5145 int template_only = 0;
5152 gcc_assert (instance != NULL_TREE);
5154 if (error_operand_p (instance)
5155 || error_operand_p (fns)
5156 || args == error_mark_node)
5157 return error_mark_node;
5159 orig_instance = instance;
5163 if (processing_template_decl)
5165 instance = build_non_dependent_expr (instance);
5166 if (!BASELINK_P (fns)
5167 && TREE_CODE (fns) != PSEUDO_DTOR_EXPR
5168 && TREE_TYPE (fns) != unknown_type_node)
5169 fns = build_non_dependent_expr (fns);
5170 args = build_non_dependent_args (orig_args);
5173 /* Process the argument list. */
5175 args = resolve_args (args);
5176 if (args == error_mark_node)
5177 return error_mark_node;
5179 if (TREE_CODE (TREE_TYPE (instance)) == REFERENCE_TYPE)
5180 instance = convert_from_reference (instance);
5181 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5182 instance_ptr = build_this (instance);
5184 if (!BASELINK_P (fns))
5186 error ("call to non-function %qD", fns);
5187 return error_mark_node;
5190 if (!conversion_path)
5191 conversion_path = BASELINK_BINFO (fns);
5192 access_binfo = BASELINK_ACCESS_BINFO (fns);
5193 optype = BASELINK_OPTYPE (fns);
5194 fns = BASELINK_FUNCTIONS (fns);
5196 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5198 explicit_targs = TREE_OPERAND (fns, 1);
5199 fns = TREE_OPERAND (fns, 0);
5203 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5204 || TREE_CODE (fns) == TEMPLATE_DECL
5205 || TREE_CODE (fns) == OVERLOAD);
5207 /* XXX this should be handled before we get here. */
5208 if (! IS_AGGR_TYPE (basetype))
5210 if ((flags & LOOKUP_COMPLAIN) && basetype != error_mark_node)
5211 error ("request for member %qD in %qE, which is of non-aggregate "
5213 fns, instance, basetype);
5215 return error_mark_node;
5218 fn = get_first_fn (fns);
5219 name = DECL_NAME (fn);
5221 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5223 /* Callers should explicitly indicate whether they want to construct
5224 the complete object or just the part without virtual bases. */
5225 gcc_assert (name != ctor_identifier);
5226 /* Similarly for destructors. */
5227 gcc_assert (name != dtor_identifier);
5230 /* It's OK to call destructors on cv-qualified objects. Therefore,
5231 convert the INSTANCE_PTR to the unqualified type, if necessary. */
5232 if (DECL_DESTRUCTOR_P (fn))
5234 tree type = build_pointer_type (basetype);
5235 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5236 instance_ptr = build_nop (type, instance_ptr);
5239 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5240 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5242 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5243 p = conversion_obstack_alloc (0);
5245 for (fn = fns; fn; fn = OVL_NEXT (fn))
5247 tree t = OVL_CURRENT (fn);
5250 /* We can end up here for copy-init of same or base class. */
5251 if ((flags & LOOKUP_ONLYCONVERTING)
5252 && DECL_NONCONVERTING_P (t))
5255 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5256 this_arglist = mem_args;
5258 this_arglist = args;
5260 if (TREE_CODE (t) == TEMPLATE_DECL)
5261 /* A member template. */
5262 add_template_candidate (&candidates, t,
5265 this_arglist, optype,
5270 else if (! template_only)
5271 add_function_candidate (&candidates, t,
5279 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5282 if (!COMPLETE_TYPE_P (basetype))
5283 cxx_incomplete_type_error (instance_ptr, basetype);
5289 pretty_name = name_as_c_string (name, basetype, &free_p);
5290 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5291 basetype, pretty_name, user_args,
5292 TREE_TYPE (TREE_TYPE (instance_ptr)));
5296 print_z_candidates (candidates);
5297 call = error_mark_node;
5301 cand = tourney (candidates);
5307 pretty_name = name_as_c_string (name, basetype, &free_p);
5308 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5310 print_z_candidates (candidates);
5313 call = error_mark_node;
5317 if (!(flags & LOOKUP_NONVIRTUAL)
5318 && DECL_PURE_VIRTUAL_P (cand->fn)
5319 && instance == current_class_ref
5320 && (DECL_CONSTRUCTOR_P (current_function_decl)
5321 || DECL_DESTRUCTOR_P (current_function_decl)))
5322 /* This is not an error, it is runtime undefined
5324 warning ((DECL_CONSTRUCTOR_P (current_function_decl) ?
5325 "abstract virtual %q#D called from constructor"
5326 : "abstract virtual %q#D called from destructor"),
5329 if (TREE_CODE (TREE_TYPE (cand->fn)) == METHOD_TYPE
5330 && is_dummy_object (instance_ptr))
5332 error ("cannot call member function %qD without object",
5334 call = error_mark_node;
5338 if (DECL_VINDEX (cand->fn) && ! (flags & LOOKUP_NONVIRTUAL)
5339 && resolves_to_fixed_type_p (instance, 0))
5340 flags |= LOOKUP_NONVIRTUAL;
5342 call = build_over_call (cand, flags);
5344 /* In an expression of the form `a->f()' where `f' turns
5345 out to be a static member function, `a' is
5346 none-the-less evaluated. */
5347 if (TREE_CODE (TREE_TYPE (cand->fn)) != METHOD_TYPE
5348 && !is_dummy_object (instance_ptr)
5349 && TREE_SIDE_EFFECTS (instance))
5350 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5356 if (processing_template_decl && call != error_mark_node)
5357 call = (build_min_non_dep
5359 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5360 orig_args, NULL_TREE));
5362 /* Free all the conversions we allocated. */
5363 obstack_free (&conversion_obstack, p);
5368 /* Returns true iff standard conversion sequence ICS1 is a proper
5369 subsequence of ICS2. */
5372 is_subseq (conversion *ics1, conversion *ics2)
5374 /* We can assume that a conversion of the same code
5375 between the same types indicates a subsequence since we only get
5376 here if the types we are converting from are the same. */
5378 while (ics1->kind == ck_rvalue
5379 || ics1->kind == ck_lvalue)
5380 ics1 = ics1->u.next;
5384 while (ics2->kind == ck_rvalue
5385 || ics2->kind == ck_lvalue)
5386 ics2 = ics2->u.next;
5388 if (ics2->kind == ck_user
5389 || ics2->kind == ck_ambig
5390 || ics2->kind == ck_identity)
5391 /* At this point, ICS1 cannot be a proper subsequence of
5392 ICS2. We can get a USER_CONV when we are comparing the
5393 second standard conversion sequence of two user conversion
5397 ics2 = ics2->u.next;
5399 if (ics2->kind == ics1->kind
5400 && same_type_p (ics2->type, ics1->type)
5401 && same_type_p (ics2->u.next->type,
5402 ics1->u.next->type))
5407 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5408 be any _TYPE nodes. */
5411 is_properly_derived_from (tree derived, tree base)
5413 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5414 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5417 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5418 considers every class derived from itself. */
5419 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5420 && DERIVED_FROM_P (base, derived));
5423 /* We build the ICS for an implicit object parameter as a pointer
5424 conversion sequence. However, such a sequence should be compared
5425 as if it were a reference conversion sequence. If ICS is the
5426 implicit conversion sequence for an implicit object parameter,
5427 modify it accordingly. */
5430 maybe_handle_implicit_object (conversion **ics)
5434 /* [over.match.funcs]
5436 For non-static member functions, the type of the
5437 implicit object parameter is "reference to cv X"
5438 where X is the class of which the function is a
5439 member and cv is the cv-qualification on the member
5440 function declaration. */
5441 conversion *t = *ics;
5442 tree reference_type;
5444 /* The `this' parameter is a pointer to a class type. Make the
5445 implicit conversion talk about a reference to that same class
5447 reference_type = TREE_TYPE (t->type);
5448 reference_type = build_reference_type (reference_type);
5450 if (t->kind == ck_qual)
5452 if (t->kind == ck_ptr)
5454 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5455 t = direct_reference_binding (reference_type, t);
5460 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5461 and return the type to which the reference refers. Otherwise,
5462 leave *ICS unchanged and return NULL_TREE. */
5465 maybe_handle_ref_bind (conversion **ics)
5467 if ((*ics)->kind == ck_ref_bind)
5469 conversion *old_ics = *ics;
5470 tree type = TREE_TYPE (old_ics->type);
5471 *ics = old_ics->u.next;
5472 (*ics)->user_conv_p = old_ics->user_conv_p;
5473 (*ics)->bad_p = old_ics->bad_p;
5480 /* Compare two implicit conversion sequences according to the rules set out in
5481 [over.ics.rank]. Return values:
5483 1: ics1 is better than ics2
5484 -1: ics2 is better than ics1
5485 0: ics1 and ics2 are indistinguishable */
5488 compare_ics (conversion *ics1, conversion *ics2)
5494 tree deref_from_type1 = NULL_TREE;
5495 tree deref_from_type2 = NULL_TREE;
5496 tree deref_to_type1 = NULL_TREE;
5497 tree deref_to_type2 = NULL_TREE;
5498 conversion_rank rank1, rank2;
5500 /* REF_BINDING is nonzero if the result of the conversion sequence
5501 is a reference type. In that case TARGET_TYPE is the
5502 type referred to by the reference. */
5506 /* Handle implicit object parameters. */
5507 maybe_handle_implicit_object (&ics1);
5508 maybe_handle_implicit_object (&ics2);
5510 /* Handle reference parameters. */
5511 target_type1 = maybe_handle_ref_bind (&ics1);
5512 target_type2 = maybe_handle_ref_bind (&ics2);
5516 When comparing the basic forms of implicit conversion sequences (as
5517 defined in _over.best.ics_)
5519 --a standard conversion sequence (_over.ics.scs_) is a better
5520 conversion sequence than a user-defined conversion sequence
5521 or an ellipsis conversion sequence, and
5523 --a user-defined conversion sequence (_over.ics.user_) is a
5524 better conversion sequence than an ellipsis conversion sequence
5525 (_over.ics.ellipsis_). */
5526 rank1 = CONVERSION_RANK (ics1);
5527 rank2 = CONVERSION_RANK (ics2);
5531 else if (rank1 < rank2)
5534 if (rank1 == cr_bad)
5536 /* XXX Isn't this an extension? */
5537 /* Both ICS are bad. We try to make a decision based on what
5538 would have happened if they'd been good. */
5539 if (ics1->user_conv_p > ics2->user_conv_p
5540 || ics1->rank > ics2->rank)
5542 else if (ics1->user_conv_p < ics2->user_conv_p
5543 || ics1->rank < ics2->rank)
5546 /* We couldn't make up our minds; try to figure it out below. */
5549 if (ics1->ellipsis_p)
5550 /* Both conversions are ellipsis conversions. */
5553 /* User-defined conversion sequence U1 is a better conversion sequence
5554 than another user-defined conversion sequence U2 if they contain the
5555 same user-defined conversion operator or constructor and if the sec-
5556 ond standard conversion sequence of U1 is better than the second
5557 standard conversion sequence of U2. */
5559 if (ics1->user_conv_p)
5564 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5565 if (t1->kind == ck_ambig)
5567 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5568 if (t2->kind == ck_ambig)
5571 if (t1->cand->fn != t2->cand->fn)
5574 /* We can just fall through here, after setting up
5575 FROM_TYPE1 and FROM_TYPE2. */
5576 from_type1 = t1->type;
5577 from_type2 = t2->type;
5584 /* We're dealing with two standard conversion sequences.
5588 Standard conversion sequence S1 is a better conversion
5589 sequence than standard conversion sequence S2 if
5591 --S1 is a proper subsequence of S2 (comparing the conversion
5592 sequences in the canonical form defined by _over.ics.scs_,
5593 excluding any Lvalue Transformation; the identity
5594 conversion sequence is considered to be a subsequence of
5595 any non-identity conversion sequence */
5598 while (t1->kind != ck_identity)
5600 from_type1 = t1->type;
5603 while (t2->kind != ck_identity)
5605 from_type2 = t2->type;
5608 if (same_type_p (from_type1, from_type2))
5610 if (is_subseq (ics1, ics2))
5612 if (is_subseq (ics2, ics1))
5615 /* Otherwise, one sequence cannot be a subsequence of the other; they
5616 don't start with the same type. This can happen when comparing the
5617 second standard conversion sequence in two user-defined conversion
5624 --the rank of S1 is better than the rank of S2 (by the rules
5627 Standard conversion sequences are ordered by their ranks: an Exact
5628 Match is a better conversion than a Promotion, which is a better
5629 conversion than a Conversion.
5631 Two conversion sequences with the same rank are indistinguishable
5632 unless one of the following rules applies:
5634 --A conversion that is not a conversion of a pointer, or pointer
5635 to member, to bool is better than another conversion that is such
5638 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5639 so that we do not have to check it explicitly. */
5640 if (ics1->rank < ics2->rank)
5642 else if (ics2->rank < ics1->rank)
5645 to_type1 = ics1->type;
5646 to_type2 = ics2->type;
5648 if (TYPE_PTR_P (from_type1)
5649 && TYPE_PTR_P (from_type2)
5650 && TYPE_PTR_P (to_type1)
5651 && TYPE_PTR_P (to_type2))
5653 deref_from_type1 = TREE_TYPE (from_type1);
5654 deref_from_type2 = TREE_TYPE (from_type2);
5655 deref_to_type1 = TREE_TYPE (to_type1);
5656 deref_to_type2 = TREE_TYPE (to_type2);
5658 /* The rules for pointers to members A::* are just like the rules
5659 for pointers A*, except opposite: if B is derived from A then
5660 A::* converts to B::*, not vice versa. For that reason, we
5661 switch the from_ and to_ variables here. */
5662 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5663 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5664 || (TYPE_PTRMEMFUNC_P (from_type1)
5665 && TYPE_PTRMEMFUNC_P (from_type2)
5666 && TYPE_PTRMEMFUNC_P (to_type1)
5667 && TYPE_PTRMEMFUNC_P (to_type2)))
5669 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5670 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5671 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5672 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5675 if (deref_from_type1 != NULL_TREE
5676 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5677 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5679 /* This was one of the pointer or pointer-like conversions.
5683 --If class B is derived directly or indirectly from class A,
5684 conversion of B* to A* is better than conversion of B* to
5685 void*, and conversion of A* to void* is better than
5686 conversion of B* to void*. */
5687 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5688 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5690 if (is_properly_derived_from (deref_from_type1,
5693 else if (is_properly_derived_from (deref_from_type2,
5697 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
5698 || TREE_CODE (deref_to_type2) == VOID_TYPE)
5700 if (same_type_p (deref_from_type1, deref_from_type2))
5702 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
5704 if (is_properly_derived_from (deref_from_type1,
5708 /* We know that DEREF_TO_TYPE1 is `void' here. */
5709 else if (is_properly_derived_from (deref_from_type1,
5714 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
5715 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
5719 --If class B is derived directly or indirectly from class A
5720 and class C is derived directly or indirectly from B,
5722 --conversion of C* to B* is better than conversion of C* to
5725 --conversion of B* to A* is better than conversion of C* to
5727 if (same_type_p (deref_from_type1, deref_from_type2))
5729 if (is_properly_derived_from (deref_to_type1,
5732 else if (is_properly_derived_from (deref_to_type2,
5736 else if (same_type_p (deref_to_type1, deref_to_type2))
5738 if (is_properly_derived_from (deref_from_type2,
5741 else if (is_properly_derived_from (deref_from_type1,
5747 else if (CLASS_TYPE_P (non_reference (from_type1))
5748 && same_type_p (from_type1, from_type2))
5750 tree from = non_reference (from_type1);
5754 --binding of an expression of type C to a reference of type
5755 B& is better than binding an expression of type C to a
5756 reference of type A&
5758 --conversion of C to B is better than conversion of C to A, */
5759 if (is_properly_derived_from (from, to_type1)
5760 && is_properly_derived_from (from, to_type2))
5762 if (is_properly_derived_from (to_type1, to_type2))
5764 else if (is_properly_derived_from (to_type2, to_type1))
5768 else if (CLASS_TYPE_P (non_reference (to_type1))
5769 && same_type_p (to_type1, to_type2))
5771 tree to = non_reference (to_type1);
5775 --binding of an expression of type B to a reference of type
5776 A& is better than binding an expression of type C to a
5777 reference of type A&,
5779 --conversion of B to A is better than conversion of C to A */
5780 if (is_properly_derived_from (from_type1, to)
5781 && is_properly_derived_from (from_type2, to))
5783 if (is_properly_derived_from (from_type2, from_type1))
5785 else if (is_properly_derived_from (from_type1, from_type2))
5792 --S1 and S2 differ only in their qualification conversion and yield
5793 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
5794 qualification signature of type T1 is a proper subset of the cv-
5795 qualification signature of type T2 */
5796 if (ics1->kind == ck_qual
5797 && ics2->kind == ck_qual
5798 && same_type_p (from_type1, from_type2))
5799 return comp_cv_qual_signature (to_type1, to_type2);
5803 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
5804 types to which the references refer are the same type except for
5805 top-level cv-qualifiers, and the type to which the reference
5806 initialized by S2 refers is more cv-qualified than the type to
5807 which the reference initialized by S1 refers */
5809 if (target_type1 && target_type2
5810 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
5811 return comp_cv_qualification (target_type2, target_type1);
5813 /* Neither conversion sequence is better than the other. */
5817 /* The source type for this standard conversion sequence. */
5820 source_type (conversion *t)
5822 for (;; t = t->u.next)
5824 if (t->kind == ck_user
5825 || t->kind == ck_ambig
5826 || t->kind == ck_identity)
5832 /* Note a warning about preferring WINNER to LOSER. We do this by storing
5833 a pointer to LOSER and re-running joust to produce the warning if WINNER
5834 is actually used. */
5837 add_warning (struct z_candidate *winner, struct z_candidate *loser)
5839 candidate_warning *cw;
5841 cw = conversion_obstack_alloc (sizeof (candidate_warning));
5843 cw->next = winner->warnings;
5844 winner->warnings = cw;
5847 /* Compare two candidates for overloading as described in
5848 [over.match.best]. Return values:
5850 1: cand1 is better than cand2
5851 -1: cand2 is better than cand1
5852 0: cand1 and cand2 are indistinguishable */
5855 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
5858 int off1 = 0, off2 = 0;
5862 /* Candidates that involve bad conversions are always worse than those
5864 if (cand1->viable > cand2->viable)
5866 if (cand1->viable < cand2->viable)
5869 /* If we have two pseudo-candidates for conversions to the same type,
5870 or two candidates for the same function, arbitrarily pick one. */
5871 if (cand1->fn == cand2->fn
5872 && (IS_TYPE_OR_DECL_P (cand1->fn)))
5875 /* a viable function F1
5876 is defined to be a better function than another viable function F2 if
5877 for all arguments i, ICSi(F1) is not a worse conversion sequence than
5878 ICSi(F2), and then */
5880 /* for some argument j, ICSj(F1) is a better conversion sequence than
5883 /* For comparing static and non-static member functions, we ignore
5884 the implicit object parameter of the non-static function. The
5885 standard says to pretend that the static function has an object
5886 parm, but that won't work with operator overloading. */
5887 len = cand1->num_convs;
5888 if (len != cand2->num_convs)
5890 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
5891 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
5893 gcc_assert (static_1 != static_2);
5904 for (i = 0; i < len; ++i)
5906 conversion *t1 = cand1->convs[i + off1];
5907 conversion *t2 = cand2->convs[i + off2];
5908 int comp = compare_ics (t1, t2);
5913 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
5914 == cr_std + cr_promotion)
5915 && t1->kind == ck_std
5916 && t2->kind == ck_std
5917 && TREE_CODE (t1->type) == INTEGER_TYPE
5918 && TREE_CODE (t2->type) == INTEGER_TYPE
5919 && (TYPE_PRECISION (t1->type)
5920 == TYPE_PRECISION (t2->type))
5921 && (TYPE_UNSIGNED (t1->u.next->type)
5922 || (TREE_CODE (t1->u.next->type)
5925 tree type = t1->u.next->type;
5927 struct z_candidate *w, *l;
5929 type1 = t1->type, type2 = t2->type,
5930 w = cand1, l = cand2;
5932 type1 = t2->type, type2 = t1->type,
5933 w = cand2, l = cand1;
5937 warning ("passing %qT chooses %qT over %qT",
5938 type, type1, type2);
5939 warning (" in call to %qD", w->fn);
5945 if (winner && comp != winner)
5954 /* warn about confusing overload resolution for user-defined conversions,
5955 either between a constructor and a conversion op, or between two
5957 if (winner && warn_conversion && cand1->second_conv
5958 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
5959 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
5961 struct z_candidate *w, *l;
5962 bool give_warning = false;
5965 w = cand1, l = cand2;
5967 w = cand2, l = cand1;
5969 /* We don't want to complain about `X::operator T1 ()'
5970 beating `X::operator T2 () const', when T2 is a no less
5971 cv-qualified version of T1. */
5972 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
5973 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
5975 tree t = TREE_TYPE (TREE_TYPE (l->fn));
5976 tree f = TREE_TYPE (TREE_TYPE (w->fn));
5978 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
5983 if (!comp_ptr_ttypes (t, f))
5984 give_warning = true;
5987 give_warning = true;
5993 tree source = source_type (w->convs[0]);
5994 if (! DECL_CONSTRUCTOR_P (w->fn))
5995 source = TREE_TYPE (source);
5996 warning ("choosing %qD over %qD", w->fn, l->fn);
5997 warning (" for conversion from %qT to %qT",
5998 source, w->second_conv->type);
5999 warning (" because conversion sequence for the argument is better");
6009 F1 is a non-template function and F2 is a template function
6012 if (!cand1->template_decl && cand2->template_decl)
6014 else if (cand1->template_decl && !cand2->template_decl)
6018 F1 and F2 are template functions and the function template for F1 is
6019 more specialized than the template for F2 according to the partial
6022 if (cand1->template_decl && cand2->template_decl)
6024 winner = more_specialized
6025 (TI_TEMPLATE (cand1->template_decl),
6026 TI_TEMPLATE (cand2->template_decl),
6028 /* Tell the deduction code how many real function arguments
6029 we saw, not counting the implicit 'this' argument. But,
6030 add_function_candidate() suppresses the "this" argument
6033 [temp.func.order]: The presence of unused ellipsis and default
6034 arguments has no effect on the partial ordering of function
6037 - (DECL_NONSTATIC_MEMBER_FUNCTION_P (cand1->fn)
6038 - DECL_CONSTRUCTOR_P (cand1->fn)));
6044 the context is an initialization by user-defined conversion (see
6045 _dcl.init_ and _over.match.user_) and the standard conversion
6046 sequence from the return type of F1 to the destination type (i.e.,
6047 the type of the entity being initialized) is a better conversion
6048 sequence than the standard conversion sequence from the return type
6049 of F2 to the destination type. */
6051 if (cand1->second_conv)
6053 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6058 /* Check whether we can discard a builtin candidate, either because we
6059 have two identical ones or matching builtin and non-builtin candidates.
6061 (Pedantically in the latter case the builtin which matched the user
6062 function should not be added to the overload set, but we spot it here.
6065 ... the builtin candidates include ...
6066 - do not have the same parameter type list as any non-template
6067 non-member candidate. */
6069 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6070 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6072 for (i = 0; i < len; ++i)
6073 if (!same_type_p (cand1->convs[i]->type,
6074 cand2->convs[i]->type))
6076 if (i == cand1->num_convs)
6078 if (cand1->fn == cand2->fn)
6079 /* Two built-in candidates; arbitrarily pick one. */
6081 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6082 /* cand1 is built-in; prefer cand2. */
6085 /* cand2 is built-in; prefer cand1. */
6090 /* If the two functions are the same (this can happen with declarations
6091 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6092 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6093 && equal_functions (cand1->fn, cand2->fn))
6098 /* Extension: If the worst conversion for one candidate is worse than the
6099 worst conversion for the other, take the first. */
6102 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6103 struct z_candidate *w = 0, *l = 0;
6105 for (i = 0; i < len; ++i)
6107 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6108 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6109 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6110 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6113 winner = 1, w = cand1, l = cand2;
6115 winner = -1, w = cand2, l = cand1;
6121 ISO C++ says that these are ambiguous, even \
6122 though the worst conversion for the first is better than \
6123 the worst conversion for the second:");
6124 print_z_candidate (_("candidate 1:"), w);
6125 print_z_candidate (_("candidate 2:"), l);
6133 gcc_assert (!winner);
6137 /* Given a list of candidates for overloading, find the best one, if any.
6138 This algorithm has a worst case of O(2n) (winner is last), and a best
6139 case of O(n/2) (totally ambiguous); much better than a sorting
6142 static struct z_candidate *
6143 tourney (struct z_candidate *candidates)
6145 struct z_candidate *champ = candidates, *challenger;
6147 int champ_compared_to_predecessor = 0;
6149 /* Walk through the list once, comparing each current champ to the next
6150 candidate, knocking out a candidate or two with each comparison. */
6152 for (challenger = champ->next; challenger; )
6154 fate = joust (champ, challenger, 0);
6156 challenger = challenger->next;
6161 champ = challenger->next;
6164 champ_compared_to_predecessor = 0;
6169 champ_compared_to_predecessor = 1;
6172 challenger = champ->next;
6176 /* Make sure the champ is better than all the candidates it hasn't yet
6177 been compared to. */
6179 for (challenger = candidates;
6181 && !(champ_compared_to_predecessor && challenger->next == champ);
6182 challenger = challenger->next)
6184 fate = joust (champ, challenger, 0);
6192 /* Returns nonzero if things of type FROM can be converted to TO. */
6195 can_convert (tree to, tree from)
6197 return can_convert_arg (to, from, NULL_TREE);
6200 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6203 can_convert_arg (tree to, tree from, tree arg)
6209 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6210 p = conversion_obstack_alloc (0);
6212 t = implicit_conversion (to, from, arg, LOOKUP_NORMAL);
6213 ok_p = (t && !t->bad_p);
6215 /* Free all the conversions we allocated. */
6216 obstack_free (&conversion_obstack, p);
6221 /* Like can_convert_arg, but allows dubious conversions as well. */
6224 can_convert_arg_bad (tree to, tree from, tree arg)
6229 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6230 p = conversion_obstack_alloc (0);
6231 /* Try to perform the conversion. */
6232 t = implicit_conversion (to, from, arg, LOOKUP_NORMAL);
6233 /* Free all the conversions we allocated. */
6234 obstack_free (&conversion_obstack, p);
6239 /* Convert EXPR to TYPE. Return the converted expression.
6241 Note that we allow bad conversions here because by the time we get to
6242 this point we are committed to doing the conversion. If we end up
6243 doing a bad conversion, convert_like will complain. */
6246 perform_implicit_conversion (tree type, tree expr)
6251 if (error_operand_p (expr))
6252 return error_mark_node;
6254 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6255 p = conversion_obstack_alloc (0);
6257 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6261 error ("could not convert %qE to %qT", expr, type);
6262 expr = error_mark_node;
6265 expr = convert_like (conv, expr);
6267 /* Free all the conversions we allocated. */
6268 obstack_free (&conversion_obstack, p);
6273 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6274 permitted. If the conversion is valid, the converted expression is
6275 returned. Otherwise, NULL_TREE is returned, except in the case
6276 that TYPE is a class type; in that case, an error is issued. */
6279 perform_direct_initialization_if_possible (tree type, tree expr)
6284 if (type == error_mark_node || error_operand_p (expr))
6285 return error_mark_node;
6288 If the destination type is a (possibly cv-qualified) class type:
6290 -- If the initialization is direct-initialization ...,
6291 constructors are considered. ... If no constructor applies, or
6292 the overload resolution is ambiguous, the initialization is
6294 if (CLASS_TYPE_P (type))
6296 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6297 build_tree_list (NULL_TREE, expr),
6298 type, LOOKUP_NORMAL);
6299 return build_cplus_new (type, expr);
6302 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6303 p = conversion_obstack_alloc (0);
6305 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6307 if (!conv || conv->bad_p)
6310 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6311 /*issue_conversion_warnings=*/false);
6313 /* Free all the conversions we allocated. */
6314 obstack_free (&conversion_obstack, p);
6319 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6320 is being bound to a temporary. Create and return a new VAR_DECL
6321 with the indicated TYPE; this variable will store the value to
6322 which the reference is bound. */
6325 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6329 /* Create the variable. */
6330 var = build_decl (VAR_DECL, NULL_TREE, type);
6331 DECL_ARTIFICIAL (var) = 1;
6332 TREE_USED (var) = 1;
6334 /* Register the variable. */
6335 if (TREE_STATIC (decl))
6337 /* Namespace-scope or local static; give it a mangled name. */
6340 TREE_STATIC (var) = 1;
6341 name = mangle_ref_init_variable (decl);
6342 DECL_NAME (var) = name;
6343 SET_DECL_ASSEMBLER_NAME (var, name);
6344 var = pushdecl_top_level (var);
6348 /* Create a new cleanup level if necessary. */
6349 maybe_push_cleanup_level (type);
6350 /* Don't push unnamed temps. Do set DECL_CONTEXT, though. */
6351 DECL_CONTEXT (var) = current_function_decl;
6357 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6358 initializing a variable of that TYPE. If DECL is non-NULL, it is
6359 the VAR_DECL being initialized with the EXPR. (In that case, the
6360 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6361 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6362 return, if *CLEANUP is no longer NULL, it will be an expression
6363 that should be pushed as a cleanup after the returned expression
6364 is used to initialize DECL.
6366 Return the converted expression. */
6369 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6374 if (type == error_mark_node || error_operand_p (expr))
6375 return error_mark_node;
6377 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6378 p = conversion_obstack_alloc (0);
6380 conv = reference_binding (type, TREE_TYPE (expr), expr, LOOKUP_NORMAL);
6381 if (!conv || conv->bad_p)
6383 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6384 && !real_lvalue_p (expr))
6385 error ("invalid initialization of non-const reference of "
6386 "type %qT from a temporary of type %qT",
6387 type, TREE_TYPE (expr));
6389 error ("invalid initialization of reference of type "
6390 "%qT from expression of type %qT", type,
6392 return error_mark_node;
6395 /* If DECL is non-NULL, then this special rule applies:
6399 The temporary to which the reference is bound or the temporary
6400 that is the complete object to which the reference is bound
6401 persists for the lifetime of the reference.
6403 The temporaries created during the evaluation of the expression
6404 initializing the reference, except the temporary to which the
6405 reference is bound, are destroyed at the end of the
6406 full-expression in which they are created.
6408 In that case, we store the converted expression into a new
6409 VAR_DECL in a new scope.
6411 However, we want to be careful not to create temporaries when
6412 they are not required. For example, given:
6415 struct D : public B {};
6419 there is no need to copy the return value from "f"; we can just
6420 extend its lifetime. Similarly, given:
6423 struct T { operator S(); };
6427 we can extend the lifetime of the return value of the conversion
6429 gcc_assert (conv->kind == ck_ref_bind);
6433 tree base_conv_type;
6435 /* Skip over the REF_BIND. */
6436 conv = conv->u.next;
6437 /* If the next conversion is a BASE_CONV, skip that too -- but
6438 remember that the conversion was required. */
6439 if (conv->kind == ck_base && conv->need_temporary_p)
6441 if (conv->check_copy_constructor_p)
6442 check_constructor_callable (TREE_TYPE (expr), expr);
6443 base_conv_type = conv->type;
6444 conv = conv->u.next;
6447 base_conv_type = NULL_TREE;
6448 /* Perform the remainder of the conversion. */
6449 expr = convert_like_real (conv, expr,
6450 /*fn=*/NULL_TREE, /*argnum=*/0,
6452 /*issue_conversion_warnings=*/true);
6453 if (!real_lvalue_p (expr))
6458 /* Create the temporary variable. */
6459 type = TREE_TYPE (expr);
6460 var = make_temporary_var_for_ref_to_temp (decl, type);
6461 layout_decl (var, 0);
6462 /* If the rvalue is the result of a function call it will be
6463 a TARGET_EXPR. If it is some other construct (such as a
6464 member access expression where the underlying object is
6465 itself the result of a function call), turn it into a
6466 TARGET_EXPR here. It is important that EXPR be a
6467 TARGET_EXPR below since otherwise the INIT_EXPR will
6468 attempt to make a bitwise copy of EXPR to initialize
6470 if (TREE_CODE (expr) != TARGET_EXPR)
6471 expr = get_target_expr (expr);
6472 /* Create the INIT_EXPR that will initialize the temporary
6474 init = build2 (INIT_EXPR, type, var, expr);
6475 if (at_function_scope_p ())
6477 add_decl_expr (var);
6478 *cleanup = cxx_maybe_build_cleanup (var);
6480 /* We must be careful to destroy the temporary only
6481 after its initialization has taken place. If the
6482 initialization throws an exception, then the
6483 destructor should not be run. We cannot simply
6484 transform INIT into something like:
6486 (INIT, ({ CLEANUP_STMT; }))
6488 because emit_local_var always treats the
6489 initializer as a full-expression. Thus, the
6490 destructor would run too early; it would run at the
6491 end of initializing the reference variable, rather
6492 than at the end of the block enclosing the
6495 The solution is to pass back a cleanup expression
6496 which the caller is responsible for attaching to
6497 the statement tree. */
6501 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6502 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6503 static_aggregates = tree_cons (NULL_TREE, var,
6506 /* Use its address to initialize the reference variable. */
6507 expr = build_address (var);
6508 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6511 /* Take the address of EXPR. */
6512 expr = build_unary_op (ADDR_EXPR, expr, 0);
6513 /* If a BASE_CONV was required, perform it now. */
6515 expr = (perform_implicit_conversion
6516 (build_pointer_type (base_conv_type), expr));
6517 expr = build_nop (type, expr);
6520 /* Perform the conversion. */
6521 expr = convert_like (conv, expr);
6523 /* Free all the conversions we allocated. */
6524 obstack_free (&conversion_obstack, p);
6529 #include "gt-cp-call.h"