1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com) and
6 modified by Brendan Kehoe (brendan@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING. If not, write to
22 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
23 Boston, MA 02110-1301, USA. */
26 /* High-level class interface. */
30 #include "coretypes.h"
39 #include "diagnostic.h"
43 #include "langhooks.h"
45 /* The various kinds of conversion. */
47 typedef enum conversion_kind {
61 /* The rank of the conversion. Order of the enumerals matters; better
62 conversions should come earlier in the list. */
64 typedef enum conversion_rank {
75 /* An implicit conversion sequence, in the sense of [over.best.ics].
76 The first conversion to be performed is at the end of the chain.
77 That conversion is always a cr_identity conversion. */
79 typedef struct conversion conversion;
81 /* The kind of conversion represented by this step. */
83 /* The rank of this conversion. */
85 BOOL_BITFIELD user_conv_p : 1;
86 BOOL_BITFIELD ellipsis_p : 1;
87 BOOL_BITFIELD this_p : 1;
88 BOOL_BITFIELD bad_p : 1;
89 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
90 temporary should be created to hold the result of the
92 BOOL_BITFIELD need_temporary_p : 1;
93 /* If KIND is ck_identity or ck_base_conv, true to indicate that the
94 copy constructor must be accessible, even though it is not being
96 BOOL_BITFIELD check_copy_constructor_p : 1;
97 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
98 from a pointer-to-derived to pointer-to-base is being performed. */
99 BOOL_BITFIELD base_p : 1;
100 /* The type of the expression resulting from the conversion. */
103 /* The next conversion in the chain. Since the conversions are
104 arranged from outermost to innermost, the NEXT conversion will
105 actually be performed before this conversion. This variant is
106 used only when KIND is neither ck_identity nor ck_ambig. */
108 /* The expression at the beginning of the conversion chain. This
109 variant is used only if KIND is ck_identity or ck_ambig. */
112 /* The function candidate corresponding to this conversion
113 sequence. This field is only used if KIND is ck_user. */
114 struct z_candidate *cand;
117 #define CONVERSION_RANK(NODE) \
118 ((NODE)->bad_p ? cr_bad \
119 : (NODE)->ellipsis_p ? cr_ellipsis \
120 : (NODE)->user_conv_p ? cr_user \
123 static struct obstack conversion_obstack;
124 static bool conversion_obstack_initialized;
126 static struct z_candidate * tourney (struct z_candidate *);
127 static int equal_functions (tree, tree);
128 static int joust (struct z_candidate *, struct z_candidate *, bool);
129 static int compare_ics (conversion *, conversion *);
130 static tree build_over_call (struct z_candidate *, int);
131 static tree build_java_interface_fn_ref (tree, tree);
132 #define convert_like(CONV, EXPR) \
133 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
134 /*issue_conversion_warnings=*/true, \
136 #define convert_like_with_context(CONV, EXPR, FN, ARGNO) \
137 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
138 /*issue_conversion_warnings=*/true, \
140 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
142 static void op_error (enum tree_code, enum tree_code, tree, tree,
144 static tree build_object_call (tree, tree);
145 static tree resolve_args (tree);
146 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
147 static void print_z_candidate (const char *, struct z_candidate *);
148 static void print_z_candidates (struct z_candidate *);
149 static tree build_this (tree);
150 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
151 static bool any_strictly_viable (struct z_candidate *);
152 static struct z_candidate *add_template_candidate
153 (struct z_candidate **, tree, tree, tree, tree, tree,
154 tree, tree, int, unification_kind_t);
155 static struct z_candidate *add_template_candidate_real
156 (struct z_candidate **, tree, tree, tree, tree, tree,
157 tree, tree, int, tree, unification_kind_t);
158 static struct z_candidate *add_template_conv_candidate
159 (struct z_candidate **, tree, tree, tree, tree, tree, tree);
160 static void add_builtin_candidates
161 (struct z_candidate **, enum tree_code, enum tree_code,
163 static void add_builtin_candidate
164 (struct z_candidate **, enum tree_code, enum tree_code,
165 tree, tree, tree, tree *, tree *, int);
166 static bool is_complete (tree);
167 static void build_builtin_candidate
168 (struct z_candidate **, tree, tree, tree, tree *, tree *,
170 static struct z_candidate *add_conv_candidate
171 (struct z_candidate **, tree, tree, tree, tree, tree);
172 static struct z_candidate *add_function_candidate
173 (struct z_candidate **, tree, tree, tree, tree, tree, int);
174 static conversion *implicit_conversion (tree, tree, tree, bool, int);
175 static conversion *standard_conversion (tree, tree, tree, bool, int);
176 static conversion *reference_binding (tree, tree, tree, int);
177 static conversion *build_conv (conversion_kind, tree, conversion *);
178 static bool is_subseq (conversion *, conversion *);
179 static tree maybe_handle_ref_bind (conversion **);
180 static void maybe_handle_implicit_object (conversion **);
181 static struct z_candidate *add_candidate
182 (struct z_candidate **, tree, tree, size_t,
183 conversion **, tree, tree, int);
184 static tree source_type (conversion *);
185 static void add_warning (struct z_candidate *, struct z_candidate *);
186 static bool reference_related_p (tree, tree);
187 static bool reference_compatible_p (tree, tree);
188 static conversion *convert_class_to_reference (tree, tree, tree);
189 static conversion *direct_reference_binding (tree, conversion *);
190 static bool promoted_arithmetic_type_p (tree);
191 static conversion *conditional_conversion (tree, tree);
192 static char *name_as_c_string (tree, tree, bool *);
193 static tree call_builtin_trap (void);
194 static tree prep_operand (tree);
195 static void add_candidates (tree, tree, tree, bool, tree, tree,
196 int, struct z_candidate **);
197 static conversion *merge_conversion_sequences (conversion *, conversion *);
198 static bool magic_varargs_p (tree);
199 typedef void (*diagnostic_fn_t) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
200 static tree build_temp (tree, tree, int, diagnostic_fn_t *);
201 static void check_constructor_callable (tree, tree);
203 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
204 NAME can take many forms... */
207 check_dtor_name (tree basetype, tree name)
209 /* Just accept something we've already complained about. */
210 if (name == error_mark_node)
213 if (TREE_CODE (name) == TYPE_DECL)
214 name = TREE_TYPE (name);
215 else if (TYPE_P (name))
217 else if (TREE_CODE (name) == IDENTIFIER_NODE)
219 if ((IS_AGGR_TYPE (basetype) && name == constructor_name (basetype))
220 || (TREE_CODE (basetype) == ENUMERAL_TYPE
221 && name == TYPE_IDENTIFIER (basetype)))
224 name = get_type_value (name);
230 template <class T> struct S { ~S(); };
234 NAME will be a class template. */
235 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
241 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
244 /* We want the address of a function or method. We avoid creating a
245 pointer-to-member function. */
248 build_addr_func (tree function)
250 tree type = TREE_TYPE (function);
252 /* We have to do these by hand to avoid real pointer to member
254 if (TREE_CODE (type) == METHOD_TYPE)
256 if (TREE_CODE (function) == OFFSET_REF)
258 tree object = build_address (TREE_OPERAND (function, 0));
259 return get_member_function_from_ptrfunc (&object,
260 TREE_OPERAND (function, 1));
262 function = build_address (function);
265 function = decay_conversion (function);
270 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
271 POINTER_TYPE to those. Note, pointer to member function types
272 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
273 two variants. build_call_a is the primitive taking an array of
274 arguments, while build_call_n is a wrapper that handles varargs. */
277 build_call_n (tree function, int n, ...)
280 return build_call_a (function, 0, NULL);
283 tree *argarray = (tree *) alloca (n * sizeof (tree));
288 for (i = 0; i < n; i++)
289 argarray[i] = va_arg (ap, tree);
291 return build_call_a (function, n, argarray);
296 build_call_a (tree function, int n, tree *argarray)
298 int is_constructor = 0;
305 function = build_addr_func (function);
307 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
308 fntype = TREE_TYPE (TREE_TYPE (function));
309 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
310 || TREE_CODE (fntype) == METHOD_TYPE);
311 result_type = TREE_TYPE (fntype);
313 if (TREE_CODE (function) == ADDR_EXPR
314 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
316 decl = TREE_OPERAND (function, 0);
317 if (!TREE_USED (decl))
319 /* We invoke build_call directly for several library
320 functions. These may have been declared normally if
321 we're building libgcc, so we can't just check
323 gcc_assert (DECL_ARTIFICIAL (decl)
324 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
332 /* We check both the decl and the type; a function may be known not to
333 throw without being declared throw(). */
334 nothrow = ((decl && TREE_NOTHROW (decl))
335 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
337 if (decl && TREE_THIS_VOLATILE (decl) && cfun)
338 current_function_returns_abnormally = 1;
340 if (decl && TREE_DEPRECATED (decl))
341 warn_deprecated_use (decl);
342 require_complete_eh_spec_types (fntype, decl);
344 if (decl && DECL_CONSTRUCTOR_P (decl))
347 /* Don't pass empty class objects by value. This is useful
348 for tags in STL, which are used to control overload resolution.
349 We don't need to handle other cases of copying empty classes. */
350 if (! decl || ! DECL_BUILT_IN (decl))
351 for (i = 0; i < n; i++)
352 if (is_empty_class (TREE_TYPE (argarray[i]))
353 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
355 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
356 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
360 function = build_call_array (result_type, function, n, argarray);
361 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
362 TREE_NOTHROW (function) = nothrow;
367 /* Build something of the form ptr->method (args)
368 or object.method (args). This can also build
369 calls to constructors, and find friends.
371 Member functions always take their class variable
374 INSTANCE is a class instance.
376 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
378 PARMS help to figure out what that NAME really refers to.
380 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
381 down to the real instance type to use for access checking. We need this
382 information to get protected accesses correct.
384 FLAGS is the logical disjunction of zero or more LOOKUP_
385 flags. See cp-tree.h for more info.
387 If this is all OK, calls build_function_call with the resolved
390 This function must also handle being called to perform
391 initialization, promotion/coercion of arguments, and
392 instantiation of default parameters.
394 Note that NAME may refer to an instance variable name. If
395 `operator()()' is defined for the type of that field, then we return
398 /* New overloading code. */
400 typedef struct z_candidate z_candidate;
402 typedef struct candidate_warning candidate_warning;
403 struct candidate_warning {
405 candidate_warning *next;
409 /* The FUNCTION_DECL that will be called if this candidate is
410 selected by overload resolution. */
412 /* The arguments to use when calling this function. */
414 /* The implicit conversion sequences for each of the arguments to
417 /* The number of implicit conversion sequences. */
419 /* If FN is a user-defined conversion, the standard conversion
420 sequence from the type returned by FN to the desired destination
422 conversion *second_conv;
424 /* If FN is a member function, the binfo indicating the path used to
425 qualify the name of FN at the call site. This path is used to
426 determine whether or not FN is accessible if it is selected by
427 overload resolution. The DECL_CONTEXT of FN will always be a
428 (possibly improper) base of this binfo. */
430 /* If FN is a non-static member function, the binfo indicating the
431 subobject to which the `this' pointer should be converted if FN
432 is selected by overload resolution. The type pointed to the by
433 the `this' pointer must correspond to the most derived class
434 indicated by the CONVERSION_PATH. */
435 tree conversion_path;
437 candidate_warning *warnings;
441 /* Returns true iff T is a null pointer constant in the sense of
445 null_ptr_cst_p (tree t)
449 A null pointer constant is an integral constant expression
450 (_expr.const_) rvalue of integer type that evaluates to zero. */
451 t = integral_constant_value (t);
454 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)) && integer_zerop (t))
457 if (!TREE_OVERFLOW (t))
463 /* Returns nonzero if PARMLIST consists of only default parms and/or
467 sufficient_parms_p (tree parmlist)
469 for (; parmlist && parmlist != void_list_node;
470 parmlist = TREE_CHAIN (parmlist))
471 if (!TREE_PURPOSE (parmlist))
476 /* Allocate N bytes of memory from the conversion obstack. The memory
477 is zeroed before being returned. */
480 conversion_obstack_alloc (size_t n)
483 if (!conversion_obstack_initialized)
485 gcc_obstack_init (&conversion_obstack);
486 conversion_obstack_initialized = true;
488 p = obstack_alloc (&conversion_obstack, n);
493 /* Dynamically allocate a conversion. */
496 alloc_conversion (conversion_kind kind)
499 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
504 #ifdef ENABLE_CHECKING
506 /* Make sure that all memory on the conversion obstack has been
510 validate_conversion_obstack (void)
512 if (conversion_obstack_initialized)
513 gcc_assert ((obstack_next_free (&conversion_obstack)
514 == obstack_base (&conversion_obstack)));
517 #endif /* ENABLE_CHECKING */
519 /* Dynamically allocate an array of N conversions. */
522 alloc_conversions (size_t n)
524 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
528 build_conv (conversion_kind code, tree type, conversion *from)
531 conversion_rank rank = CONVERSION_RANK (from);
533 /* We can't use buildl1 here because CODE could be USER_CONV, which
534 takes two arguments. In that case, the caller is responsible for
535 filling in the second argument. */
536 t = alloc_conversion (code);
559 t->user_conv_p = (code == ck_user || from->user_conv_p);
560 t->bad_p = from->bad_p;
565 /* Build a representation of the identity conversion from EXPR to
566 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
569 build_identity_conv (tree type, tree expr)
573 c = alloc_conversion (ck_identity);
580 /* Converting from EXPR to TYPE was ambiguous in the sense that there
581 were multiple user-defined conversions to accomplish the job.
582 Build a conversion that indicates that ambiguity. */
585 build_ambiguous_conv (tree type, tree expr)
589 c = alloc_conversion (ck_ambig);
597 strip_top_quals (tree t)
599 if (TREE_CODE (t) == ARRAY_TYPE)
601 return cp_build_qualified_type (t, 0);
604 /* Returns the standard conversion path (see [conv]) from type FROM to type
605 TO, if any. For proper handling of null pointer constants, you must
606 also pass the expression EXPR to convert from. If C_CAST_P is true,
607 this conversion is coming from a C-style cast. */
610 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
613 enum tree_code fcode, tcode;
615 bool fromref = false;
617 to = non_reference (to);
618 if (TREE_CODE (from) == REFERENCE_TYPE)
621 from = TREE_TYPE (from);
623 to = strip_top_quals (to);
624 from = strip_top_quals (from);
626 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
627 && expr && type_unknown_p (expr))
629 expr = instantiate_type (to, expr, tf_conv);
630 if (expr == error_mark_node)
632 from = TREE_TYPE (expr);
635 fcode = TREE_CODE (from);
636 tcode = TREE_CODE (to);
638 conv = build_identity_conv (from, expr);
639 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
641 from = type_decays_to (from);
642 fcode = TREE_CODE (from);
643 conv = build_conv (ck_lvalue, from, conv);
645 else if (fromref || (expr && lvalue_p (expr)))
650 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
653 from = strip_top_quals (bitfield_type);
654 fcode = TREE_CODE (from);
657 conv = build_conv (ck_rvalue, from, conv);
660 /* Allow conversion between `__complex__' data types. */
661 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
663 /* The standard conversion sequence to convert FROM to TO is
664 the standard conversion sequence to perform componentwise
666 conversion *part_conv = standard_conversion
667 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
671 conv = build_conv (part_conv->kind, to, conv);
672 conv->rank = part_conv->rank;
680 if (same_type_p (from, to))
683 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to))
684 && expr && null_ptr_cst_p (expr))
685 conv = build_conv (ck_std, to, conv);
686 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
687 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
689 /* For backwards brain damage compatibility, allow interconversion of
690 pointers and integers with a pedwarn. */
691 conv = build_conv (ck_std, to, conv);
694 else if (tcode == ENUMERAL_TYPE && fcode == INTEGER_TYPE)
696 /* For backwards brain damage compatibility, allow interconversion of
697 enums and integers with a pedwarn. */
698 conv = build_conv (ck_std, to, conv);
701 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
702 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
707 if (tcode == POINTER_TYPE
708 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
711 else if (VOID_TYPE_P (TREE_TYPE (to))
712 && !TYPE_PTRMEM_P (from)
713 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
715 from = build_pointer_type
716 (cp_build_qualified_type (void_type_node,
717 cp_type_quals (TREE_TYPE (from))));
718 conv = build_conv (ck_ptr, from, conv);
720 else if (TYPE_PTRMEM_P (from))
722 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
723 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
725 if (DERIVED_FROM_P (fbase, tbase)
726 && (same_type_ignoring_top_level_qualifiers_p
727 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
728 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
730 from = build_ptrmem_type (tbase,
731 TYPE_PTRMEM_POINTED_TO_TYPE (from));
732 conv = build_conv (ck_pmem, from, conv);
734 else if (!same_type_p (fbase, tbase))
737 else if (IS_AGGR_TYPE (TREE_TYPE (from))
738 && IS_AGGR_TYPE (TREE_TYPE (to))
741 An rvalue of type "pointer to cv D," where D is a
742 class type, can be converted to an rvalue of type
743 "pointer to cv B," where B is a base class (clause
744 _class.derived_) of D. If B is an inaccessible
745 (clause _class.access_) or ambiguous
746 (_class.member.lookup_) base class of D, a program
747 that necessitates this conversion is ill-formed.
748 Therefore, we use DERIVED_FROM_P, and do not check
749 access or uniqueness. */
750 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from))
751 /* If FROM is not yet complete, then we must be parsing
752 the body of a class. We know what's derived from
753 what, but we can't actually perform a
754 derived-to-base conversion. For example, in:
756 struct D : public B {
757 static const int i = sizeof((B*)(D*)0);
760 the D*-to-B* conversion is a reinterpret_cast, not a
762 && COMPLETE_TYPE_P (TREE_TYPE (from)))
765 cp_build_qualified_type (TREE_TYPE (to),
766 cp_type_quals (TREE_TYPE (from)));
767 from = build_pointer_type (from);
768 conv = build_conv (ck_ptr, from, conv);
772 if (tcode == POINTER_TYPE)
774 to_pointee = TREE_TYPE (to);
775 from_pointee = TREE_TYPE (from);
779 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
780 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
783 if (same_type_p (from, to))
785 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
786 /* In a C-style cast, we ignore CV-qualification because we
787 are allowed to perform a static_cast followed by a
789 conv = build_conv (ck_qual, to, conv);
790 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
791 conv = build_conv (ck_qual, to, conv);
792 else if (expr && string_conv_p (to, expr, 0))
793 /* converting from string constant to char *. */
794 conv = build_conv (ck_qual, to, conv);
795 else if (ptr_reasonably_similar (to_pointee, from_pointee))
797 conv = build_conv (ck_ptr, to, conv);
805 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
807 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
808 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
809 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
810 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
812 if (!DERIVED_FROM_P (fbase, tbase)
813 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
814 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
815 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
816 || cp_type_quals (fbase) != cp_type_quals (tbase))
819 from = cp_build_qualified_type (tbase, cp_type_quals (fbase));
820 from = build_method_type_directly (from,
822 TREE_CHAIN (TYPE_ARG_TYPES (fromfn)));
823 from = build_ptrmemfunc_type (build_pointer_type (from));
824 conv = build_conv (ck_pmem, from, conv);
827 else if (tcode == BOOLEAN_TYPE)
831 An rvalue of arithmetic, enumeration, pointer, or pointer to
832 member type can be converted to an rvalue of type bool. */
833 if (ARITHMETIC_TYPE_P (from)
834 || fcode == ENUMERAL_TYPE
835 || fcode == POINTER_TYPE
836 || TYPE_PTR_TO_MEMBER_P (from))
838 conv = build_conv (ck_std, to, conv);
839 if (fcode == POINTER_TYPE
840 || TYPE_PTRMEM_P (from)
841 || (TYPE_PTRMEMFUNC_P (from)
842 && conv->rank < cr_pbool))
843 conv->rank = cr_pbool;
849 /* We don't check for ENUMERAL_TYPE here because there are no standard
850 conversions to enum type. */
851 else if (tcode == INTEGER_TYPE || tcode == BOOLEAN_TYPE
852 || tcode == REAL_TYPE)
854 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE))
856 conv = build_conv (ck_std, to, conv);
858 /* Give this a better rank if it's a promotion. */
859 if (same_type_p (to, type_promotes_to (from))
860 && conv->u.next->rank <= cr_promotion)
861 conv->rank = cr_promotion;
863 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
864 && vector_types_convertible_p (from, to, false))
865 return build_conv (ck_std, to, conv);
866 else if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE)
867 && IS_AGGR_TYPE (to) && IS_AGGR_TYPE (from)
868 && is_properly_derived_from (from, to))
870 if (conv->kind == ck_rvalue)
872 conv = build_conv (ck_base, to, conv);
873 /* The derived-to-base conversion indicates the initialization
874 of a parameter with base type from an object of a derived
875 type. A temporary object is created to hold the result of
877 conv->need_temporary_p = true;
885 /* Returns nonzero if T1 is reference-related to T2. */
888 reference_related_p (tree t1, tree t2)
890 t1 = TYPE_MAIN_VARIANT (t1);
891 t2 = TYPE_MAIN_VARIANT (t2);
895 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
896 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
898 return (same_type_p (t1, t2)
899 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
900 && DERIVED_FROM_P (t1, t2)));
903 /* Returns nonzero if T1 is reference-compatible with T2. */
906 reference_compatible_p (tree t1, tree t2)
910 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
911 reference-related to T2 and cv1 is the same cv-qualification as,
912 or greater cv-qualification than, cv2. */
913 return (reference_related_p (t1, t2)
914 && at_least_as_qualified_p (t1, t2));
917 /* Determine whether or not the EXPR (of class type S) can be
918 converted to T as in [over.match.ref]. */
921 convert_class_to_reference (tree t, tree s, tree expr)
927 struct z_candidate *candidates;
928 struct z_candidate *cand;
931 conversions = lookup_conversions (s);
937 Assuming that "cv1 T" is the underlying type of the reference
938 being initialized, and "cv S" is the type of the initializer
939 expression, with S a class type, the candidate functions are
942 --The conversion functions of S and its base classes are
943 considered. Those that are not hidden within S and yield type
944 "reference to cv2 T2", where "cv1 T" is reference-compatible
945 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
947 The argument list has one argument, which is the initializer
952 /* Conceptually, we should take the address of EXPR and put it in
953 the argument list. Unfortunately, however, that can result in
954 error messages, which we should not issue now because we are just
955 trying to find a conversion operator. Therefore, we use NULL,
956 cast to the appropriate type. */
957 arglist = build_int_cst (build_pointer_type (s), 0);
958 arglist = build_tree_list (NULL_TREE, arglist);
960 reference_type = build_reference_type (t);
964 tree fns = TREE_VALUE (conversions);
966 for (; fns; fns = OVL_NEXT (fns))
968 tree f = OVL_CURRENT (fns);
969 tree t2 = TREE_TYPE (TREE_TYPE (f));
973 /* If this is a template function, try to get an exact
975 if (TREE_CODE (f) == TEMPLATE_DECL)
977 cand = add_template_candidate (&candidates,
983 TREE_PURPOSE (conversions),
989 /* Now, see if the conversion function really returns
990 an lvalue of the appropriate type. From the
991 point of view of unification, simply returning an
992 rvalue of the right type is good enough. */
994 t2 = TREE_TYPE (TREE_TYPE (f));
995 if (TREE_CODE (t2) != REFERENCE_TYPE
996 || !reference_compatible_p (t, TREE_TYPE (t2)))
998 candidates = candidates->next;
1003 else if (TREE_CODE (t2) == REFERENCE_TYPE
1004 && reference_compatible_p (t, TREE_TYPE (t2)))
1005 cand = add_function_candidate (&candidates, f, s, arglist,
1007 TREE_PURPOSE (conversions),
1012 conversion *identity_conv;
1013 /* Build a standard conversion sequence indicating the
1014 binding from the reference type returned by the
1015 function to the desired REFERENCE_TYPE. */
1017 = build_identity_conv (TREE_TYPE (TREE_TYPE
1018 (TREE_TYPE (cand->fn))),
1021 = (direct_reference_binding
1022 (reference_type, identity_conv));
1023 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1026 conversions = TREE_CHAIN (conversions);
1029 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1030 /* If none of the conversion functions worked out, let our caller
1035 cand = tourney (candidates);
1039 /* Now that we know that this is the function we're going to use fix
1040 the dummy first argument. */
1041 cand->args = tree_cons (NULL_TREE,
1043 TREE_CHAIN (cand->args));
1045 /* Build a user-defined conversion sequence representing the
1047 conv = build_conv (ck_user,
1048 TREE_TYPE (TREE_TYPE (cand->fn)),
1049 build_identity_conv (TREE_TYPE (expr), expr));
1052 /* Merge it with the standard conversion sequence from the
1053 conversion function's return type to the desired type. */
1054 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1056 if (cand->viable == -1)
1059 return cand->second_conv;
1062 /* A reference of the indicated TYPE is being bound directly to the
1063 expression represented by the implicit conversion sequence CONV.
1064 Return a conversion sequence for this binding. */
1067 direct_reference_binding (tree type, conversion *conv)
1071 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1072 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1074 t = TREE_TYPE (type);
1078 When a parameter of reference type binds directly
1079 (_dcl.init.ref_) to an argument expression, the implicit
1080 conversion sequence is the identity conversion, unless the
1081 argument expression has a type that is a derived class of the
1082 parameter type, in which case the implicit conversion sequence is
1083 a derived-to-base Conversion.
1085 If the parameter binds directly to the result of applying a
1086 conversion function to the argument expression, the implicit
1087 conversion sequence is a user-defined conversion sequence
1088 (_over.ics.user_), with the second standard conversion sequence
1089 either an identity conversion or, if the conversion function
1090 returns an entity of a type that is a derived class of the
1091 parameter type, a derived-to-base conversion. */
1092 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1094 /* Represent the derived-to-base conversion. */
1095 conv = build_conv (ck_base, t, conv);
1096 /* We will actually be binding to the base-class subobject in
1097 the derived class, so we mark this conversion appropriately.
1098 That way, convert_like knows not to generate a temporary. */
1099 conv->need_temporary_p = false;
1101 return build_conv (ck_ref_bind, type, conv);
1104 /* Returns the conversion path from type FROM to reference type TO for
1105 purposes of reference binding. For lvalue binding, either pass a
1106 reference type to FROM or an lvalue expression to EXPR. If the
1107 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1108 the conversion returned. */
1111 reference_binding (tree rto, tree rfrom, tree expr, int flags)
1113 conversion *conv = NULL;
1114 tree to = TREE_TYPE (rto);
1118 cp_lvalue_kind lvalue_p = clk_none;
1120 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1122 expr = instantiate_type (to, expr, tf_none);
1123 if (expr == error_mark_node)
1125 from = TREE_TYPE (expr);
1128 if (TREE_CODE (from) == REFERENCE_TYPE)
1130 /* Anything with reference type is an lvalue. */
1131 lvalue_p = clk_ordinary;
1132 from = TREE_TYPE (from);
1135 lvalue_p = real_lvalue_p (expr);
1137 /* Figure out whether or not the types are reference-related and
1138 reference compatible. We have do do this after stripping
1139 references from FROM. */
1140 related_p = reference_related_p (to, from);
1141 compatible_p = reference_compatible_p (to, from);
1143 if (lvalue_p && compatible_p)
1147 If the initializer expression
1149 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1150 is reference-compatible with "cv2 T2,"
1152 the reference is bound directly to the initializer expression
1154 conv = build_identity_conv (from, expr);
1155 conv = direct_reference_binding (rto, conv);
1156 if ((lvalue_p & clk_bitfield) != 0
1157 || ((lvalue_p & clk_packed) != 0 && !TYPE_PACKED (to)))
1158 /* For the purposes of overload resolution, we ignore the fact
1159 this expression is a bitfield or packed field. (In particular,
1160 [over.ics.ref] says specifically that a function with a
1161 non-const reference parameter is viable even if the
1162 argument is a bitfield.)
1164 However, when we actually call the function we must create
1165 a temporary to which to bind the reference. If the
1166 reference is volatile, or isn't const, then we cannot make
1167 a temporary, so we just issue an error when the conversion
1169 conv->need_temporary_p = true;
1173 else if (CLASS_TYPE_P (from) && !(flags & LOOKUP_NO_CONVERSION))
1177 If the initializer expression
1179 -- has a class type (i.e., T2 is a class type) can be
1180 implicitly converted to an lvalue of type "cv3 T3," where
1181 "cv1 T1" is reference-compatible with "cv3 T3". (this
1182 conversion is selected by enumerating the applicable
1183 conversion functions (_over.match.ref_) and choosing the
1184 best one through overload resolution. (_over.match_).
1186 the reference is bound to the lvalue result of the conversion
1187 in the second case. */
1188 conv = convert_class_to_reference (to, from, expr);
1193 /* From this point on, we conceptually need temporaries, even if we
1194 elide them. Only the cases above are "direct bindings". */
1195 if (flags & LOOKUP_NO_TEMP_BIND)
1200 When a parameter of reference type is not bound directly to an
1201 argument expression, the conversion sequence is the one required
1202 to convert the argument expression to the underlying type of the
1203 reference according to _over.best.ics_. Conceptually, this
1204 conversion sequence corresponds to copy-initializing a temporary
1205 of the underlying type with the argument expression. Any
1206 difference in top-level cv-qualification is subsumed by the
1207 initialization itself and does not constitute a conversion. */
1211 Otherwise, the reference shall be to a non-volatile const type. */
1212 if (!CP_TYPE_CONST_NON_VOLATILE_P (to))
1217 If the initializer expression is an rvalue, with T2 a class type,
1218 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1219 is bound in one of the following ways:
1221 -- The reference is bound to the object represented by the rvalue
1222 or to a sub-object within that object.
1226 We use the first alternative. The implicit conversion sequence
1227 is supposed to be same as we would obtain by generating a
1228 temporary. Fortunately, if the types are reference compatible,
1229 then this is either an identity conversion or the derived-to-base
1230 conversion, just as for direct binding. */
1231 if (CLASS_TYPE_P (from) && compatible_p)
1233 conv = build_identity_conv (from, expr);
1234 conv = direct_reference_binding (rto, conv);
1235 if (!(flags & LOOKUP_CONSTRUCTOR_CALLABLE))
1236 conv->u.next->check_copy_constructor_p = true;
1242 Otherwise, a temporary of type "cv1 T1" is created and
1243 initialized from the initializer expression using the rules for a
1244 non-reference copy initialization. If T1 is reference-related to
1245 T2, cv1 must be the same cv-qualification as, or greater
1246 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1247 if (related_p && !at_least_as_qualified_p (to, from))
1250 conv = implicit_conversion (to, from, expr, /*c_cast_p=*/false,
1255 conv = build_conv (ck_ref_bind, rto, conv);
1256 /* This reference binding, unlike those above, requires the
1257 creation of a temporary. */
1258 conv->need_temporary_p = true;
1263 /* Returns the implicit conversion sequence (see [over.ics]) from type
1264 FROM to type TO. The optional expression EXPR may affect the
1265 conversion. FLAGS are the usual overloading flags. Only
1266 LOOKUP_NO_CONVERSION is significant. If C_CAST_P is true, this
1267 conversion is coming from a C-style cast. */
1270 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1275 if (from == error_mark_node || to == error_mark_node
1276 || expr == error_mark_node)
1279 if (TREE_CODE (to) == REFERENCE_TYPE)
1280 conv = reference_binding (to, from, expr, flags);
1282 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1287 if (expr != NULL_TREE
1288 && (IS_AGGR_TYPE (from)
1289 || IS_AGGR_TYPE (to))
1290 && (flags & LOOKUP_NO_CONVERSION) == 0)
1292 struct z_candidate *cand;
1294 cand = build_user_type_conversion_1
1295 (to, expr, LOOKUP_ONLYCONVERTING);
1297 conv = cand->second_conv;
1299 /* We used to try to bind a reference to a temporary here, but that
1300 is now handled by the recursive call to this function at the end
1301 of reference_binding. */
1308 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1311 static struct z_candidate *
1312 add_candidate (struct z_candidate **candidates,
1314 size_t num_convs, conversion **convs,
1315 tree access_path, tree conversion_path,
1318 struct z_candidate *cand = (struct z_candidate *)
1319 conversion_obstack_alloc (sizeof (struct z_candidate));
1323 cand->convs = convs;
1324 cand->num_convs = num_convs;
1325 cand->access_path = access_path;
1326 cand->conversion_path = conversion_path;
1327 cand->viable = viable;
1328 cand->next = *candidates;
1334 /* Create an overload candidate for the function or method FN called with
1335 the argument list ARGLIST and add it to CANDIDATES. FLAGS is passed on
1336 to implicit_conversion.
1338 CTYPE, if non-NULL, is the type we want to pretend this function
1339 comes from for purposes of overload resolution. */
1341 static struct z_candidate *
1342 add_function_candidate (struct z_candidate **candidates,
1343 tree fn, tree ctype, tree arglist,
1344 tree access_path, tree conversion_path,
1347 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1350 tree parmnode, argnode;
1354 /* At this point we should not see any functions which haven't been
1355 explicitly declared, except for friend functions which will have
1356 been found using argument dependent lookup. */
1357 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1359 /* The `this', `in_chrg' and VTT arguments to constructors are not
1360 considered in overload resolution. */
1361 if (DECL_CONSTRUCTOR_P (fn))
1363 parmlist = skip_artificial_parms_for (fn, parmlist);
1364 orig_arglist = arglist;
1365 arglist = skip_artificial_parms_for (fn, arglist);
1368 orig_arglist = arglist;
1370 len = list_length (arglist);
1371 convs = alloc_conversions (len);
1373 /* 13.3.2 - Viable functions [over.match.viable]
1374 First, to be a viable function, a candidate function shall have enough
1375 parameters to agree in number with the arguments in the list.
1377 We need to check this first; otherwise, checking the ICSes might cause
1378 us to produce an ill-formed template instantiation. */
1380 parmnode = parmlist;
1381 for (i = 0; i < len; ++i)
1383 if (parmnode == NULL_TREE || parmnode == void_list_node)
1385 parmnode = TREE_CHAIN (parmnode);
1388 if (i < len && parmnode)
1391 /* Make sure there are default args for the rest of the parms. */
1392 else if (!sufficient_parms_p (parmnode))
1398 /* Second, for F to be a viable function, there shall exist for each
1399 argument an implicit conversion sequence that converts that argument
1400 to the corresponding parameter of F. */
1402 parmnode = parmlist;
1405 for (i = 0; i < len; ++i)
1407 tree arg = TREE_VALUE (argnode);
1408 tree argtype = lvalue_type (arg);
1412 if (parmnode == void_list_node)
1415 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1416 && ! DECL_CONSTRUCTOR_P (fn));
1420 tree parmtype = TREE_VALUE (parmnode);
1422 /* The type of the implicit object parameter ('this') for
1423 overload resolution is not always the same as for the
1424 function itself; conversion functions are considered to
1425 be members of the class being converted, and functions
1426 introduced by a using-declaration are considered to be
1427 members of the class that uses them.
1429 Since build_over_call ignores the ICS for the `this'
1430 parameter, we can just change the parm type. */
1431 if (ctype && is_this)
1434 = build_qualified_type (ctype,
1435 TYPE_QUALS (TREE_TYPE (parmtype)));
1436 parmtype = build_pointer_type (parmtype);
1439 t = implicit_conversion (parmtype, argtype, arg,
1440 /*c_cast_p=*/false, flags);
1444 t = build_identity_conv (argtype, arg);
1445 t->ellipsis_p = true;
1462 parmnode = TREE_CHAIN (parmnode);
1463 argnode = TREE_CHAIN (argnode);
1467 return add_candidate (candidates, fn, orig_arglist, len, convs,
1468 access_path, conversion_path, viable);
1471 /* Create an overload candidate for the conversion function FN which will
1472 be invoked for expression OBJ, producing a pointer-to-function which
1473 will in turn be called with the argument list ARGLIST, and add it to
1474 CANDIDATES. FLAGS is passed on to implicit_conversion.
1476 Actually, we don't really care about FN; we care about the type it
1477 converts to. There may be multiple conversion functions that will
1478 convert to that type, and we rely on build_user_type_conversion_1 to
1479 choose the best one; so when we create our candidate, we record the type
1480 instead of the function. */
1482 static struct z_candidate *
1483 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1484 tree arglist, tree access_path, tree conversion_path)
1486 tree totype = TREE_TYPE (TREE_TYPE (fn));
1487 int i, len, viable, flags;
1488 tree parmlist, parmnode, argnode;
1491 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1492 parmlist = TREE_TYPE (parmlist);
1493 parmlist = TYPE_ARG_TYPES (parmlist);
1495 len = list_length (arglist) + 1;
1496 convs = alloc_conversions (len);
1497 parmnode = parmlist;
1500 flags = LOOKUP_NORMAL;
1502 /* Don't bother looking up the same type twice. */
1503 if (*candidates && (*candidates)->fn == totype)
1506 for (i = 0; i < len; ++i)
1508 tree arg = i == 0 ? obj : TREE_VALUE (argnode);
1509 tree argtype = lvalue_type (arg);
1513 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1515 else if (parmnode == void_list_node)
1518 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1519 /*c_cast_p=*/false, flags);
1522 t = build_identity_conv (argtype, arg);
1523 t->ellipsis_p = true;
1537 parmnode = TREE_CHAIN (parmnode);
1538 argnode = TREE_CHAIN (argnode);
1544 if (!sufficient_parms_p (parmnode))
1547 return add_candidate (candidates, totype, arglist, len, convs,
1548 access_path, conversion_path, viable);
1552 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
1553 tree type1, tree type2, tree *args, tree *argtypes,
1565 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
1566 convs = alloc_conversions (num_convs);
1568 for (i = 0; i < 2; ++i)
1573 t = implicit_conversion (types[i], argtypes[i], args[i],
1574 /*c_cast_p=*/false, flags);
1578 /* We need something for printing the candidate. */
1579 t = build_identity_conv (types[i], NULL_TREE);
1586 /* For COND_EXPR we rearranged the arguments; undo that now. */
1589 convs[2] = convs[1];
1590 convs[1] = convs[0];
1591 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
1592 /*c_cast_p=*/false, flags);
1599 add_candidate (candidates, fnname, /*args=*/NULL_TREE,
1601 /*access_path=*/NULL_TREE,
1602 /*conversion_path=*/NULL_TREE,
1607 is_complete (tree t)
1609 return COMPLETE_TYPE_P (complete_type (t));
1612 /* Returns nonzero if TYPE is a promoted arithmetic type. */
1615 promoted_arithmetic_type_p (tree type)
1619 In this section, the term promoted integral type is used to refer
1620 to those integral types which are preserved by integral promotion
1621 (including e.g. int and long but excluding e.g. char).
1622 Similarly, the term promoted arithmetic type refers to promoted
1623 integral types plus floating types. */
1624 return ((INTEGRAL_TYPE_P (type)
1625 && same_type_p (type_promotes_to (type), type))
1626 || TREE_CODE (type) == REAL_TYPE);
1629 /* Create any builtin operator overload candidates for the operator in
1630 question given the converted operand types TYPE1 and TYPE2. The other
1631 args are passed through from add_builtin_candidates to
1632 build_builtin_candidate.
1634 TYPE1 and TYPE2 may not be permissible, and we must filter them.
1635 If CODE is requires candidates operands of the same type of the kind
1636 of which TYPE1 and TYPE2 are, we add both candidates
1637 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
1640 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
1641 enum tree_code code2, tree fnname, tree type1,
1642 tree type2, tree *args, tree *argtypes, int flags)
1646 case POSTINCREMENT_EXPR:
1647 case POSTDECREMENT_EXPR:
1648 args[1] = integer_zero_node;
1649 type2 = integer_type_node;
1658 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
1659 and VQ is either volatile or empty, there exist candidate operator
1660 functions of the form
1661 VQ T& operator++(VQ T&);
1662 T operator++(VQ T&, int);
1663 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
1664 type other than bool, and VQ is either volatile or empty, there exist
1665 candidate operator functions of the form
1666 VQ T& operator--(VQ T&);
1667 T operator--(VQ T&, int);
1668 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
1669 complete object type, and VQ is either volatile or empty, there exist
1670 candidate operator functions of the form
1671 T*VQ& operator++(T*VQ&);
1672 T*VQ& operator--(T*VQ&);
1673 T* operator++(T*VQ&, int);
1674 T* operator--(T*VQ&, int); */
1676 case POSTDECREMENT_EXPR:
1677 case PREDECREMENT_EXPR:
1678 if (TREE_CODE (type1) == BOOLEAN_TYPE)
1680 case POSTINCREMENT_EXPR:
1681 case PREINCREMENT_EXPR:
1682 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
1684 type1 = build_reference_type (type1);
1689 /* 7 For every cv-qualified or cv-unqualified complete object type T, there
1690 exist candidate operator functions of the form
1694 8 For every function type T, there exist candidate operator functions of
1696 T& operator*(T*); */
1699 if (TREE_CODE (type1) == POINTER_TYPE
1700 && (TYPE_PTROB_P (type1)
1701 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
1705 /* 9 For every type T, there exist candidate operator functions of the form
1708 10For every promoted arithmetic type T, there exist candidate operator
1709 functions of the form
1713 case UNARY_PLUS_EXPR: /* unary + */
1714 if (TREE_CODE (type1) == POINTER_TYPE)
1717 if (ARITHMETIC_TYPE_P (type1))
1721 /* 11For every promoted integral type T, there exist candidate operator
1722 functions of the form
1726 if (INTEGRAL_TYPE_P (type1))
1730 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
1731 is the same type as C2 or is a derived class of C2, T is a complete
1732 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
1733 there exist candidate operator functions of the form
1734 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
1735 where CV12 is the union of CV1 and CV2. */
1738 if (TREE_CODE (type1) == POINTER_TYPE
1739 && TYPE_PTR_TO_MEMBER_P (type2))
1741 tree c1 = TREE_TYPE (type1);
1742 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
1744 if (IS_AGGR_TYPE (c1) && DERIVED_FROM_P (c2, c1)
1745 && (TYPE_PTRMEMFUNC_P (type2)
1746 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
1751 /* 13For every pair of promoted arithmetic types L and R, there exist can-
1752 didate operator functions of the form
1757 bool operator<(L, R);
1758 bool operator>(L, R);
1759 bool operator<=(L, R);
1760 bool operator>=(L, R);
1761 bool operator==(L, R);
1762 bool operator!=(L, R);
1763 where LR is the result of the usual arithmetic conversions between
1766 14For every pair of types T and I, where T is a cv-qualified or cv-
1767 unqualified complete object type and I is a promoted integral type,
1768 there exist candidate operator functions of the form
1769 T* operator+(T*, I);
1770 T& operator[](T*, I);
1771 T* operator-(T*, I);
1772 T* operator+(I, T*);
1773 T& operator[](I, T*);
1775 15For every T, where T is a pointer to complete object type, there exist
1776 candidate operator functions of the form112)
1777 ptrdiff_t operator-(T, T);
1779 16For every pointer or enumeration type T, there exist candidate operator
1780 functions of the form
1781 bool operator<(T, T);
1782 bool operator>(T, T);
1783 bool operator<=(T, T);
1784 bool operator>=(T, T);
1785 bool operator==(T, T);
1786 bool operator!=(T, T);
1788 17For every pointer to member type T, there exist candidate operator
1789 functions of the form
1790 bool operator==(T, T);
1791 bool operator!=(T, T); */
1794 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
1796 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1798 type2 = ptrdiff_type_node;
1802 case TRUNC_DIV_EXPR:
1803 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1809 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1810 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
1812 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
1817 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
1829 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1831 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1833 if (TREE_CODE (type1) == ENUMERAL_TYPE
1834 && TREE_CODE (type2) == ENUMERAL_TYPE)
1836 if (TYPE_PTR_P (type1)
1837 && null_ptr_cst_p (args[1])
1838 && !uses_template_parms (type1))
1843 if (null_ptr_cst_p (args[0])
1844 && TYPE_PTR_P (type2)
1845 && !uses_template_parms (type2))
1853 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1856 if (INTEGRAL_TYPE_P (type1) && TYPE_PTROB_P (type2))
1858 type1 = ptrdiff_type_node;
1861 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1863 type2 = ptrdiff_type_node;
1868 /* 18For every pair of promoted integral types L and R, there exist candi-
1869 date operator functions of the form
1876 where LR is the result of the usual arithmetic conversions between
1879 case TRUNC_MOD_EXPR:
1885 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1889 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
1890 type, VQ is either volatile or empty, and R is a promoted arithmetic
1891 type, there exist candidate operator functions of the form
1892 VQ L& operator=(VQ L&, R);
1893 VQ L& operator*=(VQ L&, R);
1894 VQ L& operator/=(VQ L&, R);
1895 VQ L& operator+=(VQ L&, R);
1896 VQ L& operator-=(VQ L&, R);
1898 20For every pair T, VQ), where T is any type and VQ is either volatile
1899 or empty, there exist candidate operator functions of the form
1900 T*VQ& operator=(T*VQ&, T*);
1902 21For every pair T, VQ), where T is a pointer to member type and VQ is
1903 either volatile or empty, there exist candidate operator functions of
1905 VQ T& operator=(VQ T&, T);
1907 22For every triple T, VQ, I), where T is a cv-qualified or cv-
1908 unqualified complete object type, VQ is either volatile or empty, and
1909 I is a promoted integral type, there exist candidate operator func-
1911 T*VQ& operator+=(T*VQ&, I);
1912 T*VQ& operator-=(T*VQ&, I);
1914 23For every triple L, VQ, R), where L is an integral or enumeration
1915 type, VQ is either volatile or empty, and R is a promoted integral
1916 type, there exist candidate operator functions of the form
1918 VQ L& operator%=(VQ L&, R);
1919 VQ L& operator<<=(VQ L&, R);
1920 VQ L& operator>>=(VQ L&, R);
1921 VQ L& operator&=(VQ L&, R);
1922 VQ L& operator^=(VQ L&, R);
1923 VQ L& operator|=(VQ L&, R); */
1930 if (TYPE_PTROB_P (type1) && INTEGRAL_TYPE_P (type2))
1932 type2 = ptrdiff_type_node;
1936 case TRUNC_DIV_EXPR:
1937 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1941 case TRUNC_MOD_EXPR:
1947 if (INTEGRAL_TYPE_P (type1) && INTEGRAL_TYPE_P (type2))
1952 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
1954 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
1955 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
1956 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
1957 || ((TYPE_PTRMEMFUNC_P (type1)
1958 || TREE_CODE (type1) == POINTER_TYPE)
1959 && null_ptr_cst_p (args[1])))
1969 type1 = build_reference_type (type1);
1975 For every pair of promoted arithmetic types L and R, there
1976 exist candidate operator functions of the form
1978 LR operator?(bool, L, R);
1980 where LR is the result of the usual arithmetic conversions
1981 between types L and R.
1983 For every type T, where T is a pointer or pointer-to-member
1984 type, there exist candidate operator functions of the form T
1985 operator?(bool, T, T); */
1987 if (promoted_arithmetic_type_p (type1)
1988 && promoted_arithmetic_type_p (type2))
1992 /* Otherwise, the types should be pointers. */
1993 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
1994 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
1997 /* We don't check that the two types are the same; the logic
1998 below will actually create two candidates; one in which both
1999 parameter types are TYPE1, and one in which both parameter
2007 /* If we're dealing with two pointer types or two enumeral types,
2008 we need candidates for both of them. */
2009 if (type2 && !same_type_p (type1, type2)
2010 && TREE_CODE (type1) == TREE_CODE (type2)
2011 && (TREE_CODE (type1) == REFERENCE_TYPE
2012 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2013 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2014 || TYPE_PTRMEMFUNC_P (type1)
2015 || IS_AGGR_TYPE (type1)
2016 || TREE_CODE (type1) == ENUMERAL_TYPE))
2018 build_builtin_candidate
2019 (candidates, fnname, type1, type1, args, argtypes, flags);
2020 build_builtin_candidate
2021 (candidates, fnname, type2, type2, args, argtypes, flags);
2025 build_builtin_candidate
2026 (candidates, fnname, type1, type2, args, argtypes, flags);
2030 type_decays_to (tree type)
2032 if (TREE_CODE (type) == ARRAY_TYPE)
2033 return build_pointer_type (TREE_TYPE (type));
2034 if (TREE_CODE (type) == FUNCTION_TYPE)
2035 return build_pointer_type (type);
2039 /* There are three conditions of builtin candidates:
2041 1) bool-taking candidates. These are the same regardless of the input.
2042 2) pointer-pair taking candidates. These are generated for each type
2043 one of the input types converts to.
2044 3) arithmetic candidates. According to the standard, we should generate
2045 all of these, but I'm trying not to...
2047 Here we generate a superset of the possible candidates for this particular
2048 case. That is a subset of the full set the standard defines, plus some
2049 other cases which the standard disallows. add_builtin_candidate will
2050 filter out the invalid set. */
2053 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2054 enum tree_code code2, tree fnname, tree *args,
2059 tree type, argtypes[3];
2060 /* TYPES[i] is the set of possible builtin-operator parameter types
2061 we will consider for the Ith argument. These are represented as
2062 a TREE_LIST; the TREE_VALUE of each node is the potential
2066 for (i = 0; i < 3; ++i)
2069 argtypes[i] = lvalue_type (args[i]);
2071 argtypes[i] = NULL_TREE;
2076 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2077 and VQ is either volatile or empty, there exist candidate operator
2078 functions of the form
2079 VQ T& operator++(VQ T&); */
2081 case POSTINCREMENT_EXPR:
2082 case PREINCREMENT_EXPR:
2083 case POSTDECREMENT_EXPR:
2084 case PREDECREMENT_EXPR:
2089 /* 24There also exist candidate operator functions of the form
2090 bool operator!(bool);
2091 bool operator&&(bool, bool);
2092 bool operator||(bool, bool); */
2094 case TRUTH_NOT_EXPR:
2095 build_builtin_candidate
2096 (candidates, fnname, boolean_type_node,
2097 NULL_TREE, args, argtypes, flags);
2100 case TRUTH_ORIF_EXPR:
2101 case TRUTH_ANDIF_EXPR:
2102 build_builtin_candidate
2103 (candidates, fnname, boolean_type_node,
2104 boolean_type_node, args, argtypes, flags);
2126 types[0] = types[1] = NULL_TREE;
2128 for (i = 0; i < 2; ++i)
2132 else if (IS_AGGR_TYPE (argtypes[i]))
2136 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2139 convs = lookup_conversions (argtypes[i]);
2141 if (code == COND_EXPR)
2143 if (real_lvalue_p (args[i]))
2144 types[i] = tree_cons
2145 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2147 types[i] = tree_cons
2148 (NULL_TREE, TYPE_MAIN_VARIANT (argtypes[i]), types[i]);
2154 for (; convs; convs = TREE_CHAIN (convs))
2156 type = TREE_TYPE (TREE_TYPE (OVL_CURRENT (TREE_VALUE (convs))));
2159 && (TREE_CODE (type) != REFERENCE_TYPE
2160 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2163 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2164 types[i] = tree_cons (NULL_TREE, type, types[i]);
2166 type = non_reference (type);
2167 if (i != 0 || ! ref1)
2169 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2170 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2171 types[i] = tree_cons (NULL_TREE, type, types[i]);
2172 if (INTEGRAL_TYPE_P (type))
2173 type = type_promotes_to (type);
2176 if (! value_member (type, types[i]))
2177 types[i] = tree_cons (NULL_TREE, type, types[i]);
2182 if (code == COND_EXPR && real_lvalue_p (args[i]))
2183 types[i] = tree_cons
2184 (NULL_TREE, build_reference_type (argtypes[i]), types[i]);
2185 type = non_reference (argtypes[i]);
2186 if (i != 0 || ! ref1)
2188 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2189 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2190 types[i] = tree_cons (NULL_TREE, type, types[i]);
2191 if (INTEGRAL_TYPE_P (type))
2192 type = type_promotes_to (type);
2194 types[i] = tree_cons (NULL_TREE, type, types[i]);
2198 /* Run through the possible parameter types of both arguments,
2199 creating candidates with those parameter types. */
2200 for (; types[0]; types[0] = TREE_CHAIN (types[0]))
2203 for (type = types[1]; type; type = TREE_CHAIN (type))
2204 add_builtin_candidate
2205 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2206 TREE_VALUE (type), args, argtypes, flags);
2208 add_builtin_candidate
2209 (candidates, code, code2, fnname, TREE_VALUE (types[0]),
2210 NULL_TREE, args, argtypes, flags);
2215 /* If TMPL can be successfully instantiated as indicated by
2216 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2218 TMPL is the template. EXPLICIT_TARGS are any explicit template
2219 arguments. ARGLIST is the arguments provided at the call-site.
2220 The RETURN_TYPE is the desired type for conversion operators. If
2221 OBJ is NULL_TREE, FLAGS and CTYPE are as for add_function_candidate.
2222 If an OBJ is supplied, FLAGS and CTYPE are ignored, and OBJ is as for
2223 add_conv_candidate. */
2225 static struct z_candidate*
2226 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2227 tree ctype, tree explicit_targs, tree arglist,
2228 tree return_type, tree access_path,
2229 tree conversion_path, int flags, tree obj,
2230 unification_kind_t strict)
2232 int ntparms = DECL_NTPARMS (tmpl);
2233 tree targs = make_tree_vec (ntparms);
2234 tree args_without_in_chrg = arglist;
2235 struct z_candidate *cand;
2239 /* We don't do deduction on the in-charge parameter, the VTT
2240 parameter or 'this'. */
2241 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2242 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2244 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2245 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2246 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2247 args_without_in_chrg = TREE_CHAIN (args_without_in_chrg);
2249 i = fn_type_unification (tmpl, explicit_targs, targs,
2250 args_without_in_chrg,
2251 return_type, strict, flags);
2256 fn = instantiate_template (tmpl, targs, tf_none);
2257 if (fn == error_mark_node)
2262 A member function template is never instantiated to perform the
2263 copy of a class object to an object of its class type.
2265 It's a little unclear what this means; the standard explicitly
2266 does allow a template to be used to copy a class. For example,
2271 template <class T> A(const T&);
2274 void g () { A a (f ()); }
2276 the member template will be used to make the copy. The section
2277 quoted above appears in the paragraph that forbids constructors
2278 whose only parameter is (a possibly cv-qualified variant of) the
2279 class type, and a logical interpretation is that the intent was
2280 to forbid the instantiation of member templates which would then
2282 if (DECL_CONSTRUCTOR_P (fn) && list_length (arglist) == 2)
2284 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2285 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2290 if (obj != NULL_TREE)
2291 /* Aha, this is a conversion function. */
2292 cand = add_conv_candidate (candidates, fn, obj, access_path,
2293 conversion_path, arglist);
2295 cand = add_function_candidate (candidates, fn, ctype,
2296 arglist, access_path,
2297 conversion_path, flags);
2298 if (DECL_TI_TEMPLATE (fn) != tmpl)
2299 /* This situation can occur if a member template of a template
2300 class is specialized. Then, instantiate_template might return
2301 an instantiation of the specialization, in which case the
2302 DECL_TI_TEMPLATE field will point at the original
2303 specialization. For example:
2305 template <class T> struct S { template <class U> void f(U);
2306 template <> void f(int) {}; };
2310 Here, TMPL will be template <class U> S<double>::f(U).
2311 And, instantiate template will give us the specialization
2312 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2313 for this will point at template <class T> template <> S<T>::f(int),
2314 so that we can find the definition. For the purposes of
2315 overload resolution, however, we want the original TMPL. */
2316 cand->template_decl = tree_cons (tmpl, targs, NULL_TREE);
2318 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2324 static struct z_candidate *
2325 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2326 tree explicit_targs, tree arglist, tree return_type,
2327 tree access_path, tree conversion_path, int flags,
2328 unification_kind_t strict)
2331 add_template_candidate_real (candidates, tmpl, ctype,
2332 explicit_targs, arglist, return_type,
2333 access_path, conversion_path,
2334 flags, NULL_TREE, strict);
2338 static struct z_candidate *
2339 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2340 tree obj, tree arglist, tree return_type,
2341 tree access_path, tree conversion_path)
2344 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2345 arglist, return_type, access_path,
2346 conversion_path, 0, obj, DEDUCE_CONV);
2349 /* The CANDS are the set of candidates that were considered for
2350 overload resolution. Return the set of viable candidates. If none
2351 of the candidates were viable, set *ANY_VIABLE_P to true. STRICT_P
2352 is true if a candidate should be considered viable only if it is
2355 static struct z_candidate*
2356 splice_viable (struct z_candidate *cands,
2360 struct z_candidate *viable;
2361 struct z_candidate **last_viable;
2362 struct z_candidate **cand;
2365 last_viable = &viable;
2366 *any_viable_p = false;
2371 struct z_candidate *c = *cand;
2372 if (strict_p ? c->viable == 1 : c->viable)
2377 last_viable = &c->next;
2378 *any_viable_p = true;
2384 return viable ? viable : cands;
2388 any_strictly_viable (struct z_candidate *cands)
2390 for (; cands; cands = cands->next)
2391 if (cands->viable == 1)
2396 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2397 words, it is about to become the "this" pointer for a member
2398 function call. Take the address of the object. */
2401 build_this (tree obj)
2403 /* In a template, we are only concerned about the type of the
2404 expression, so we can take a shortcut. */
2405 if (processing_template_decl)
2406 return build_address (obj);
2408 return build_unary_op (ADDR_EXPR, obj, 0);
2411 /* Returns true iff functions are equivalent. Equivalent functions are
2412 not '==' only if one is a function-local extern function or if
2413 both are extern "C". */
2416 equal_functions (tree fn1, tree fn2)
2418 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2419 || DECL_EXTERN_C_FUNCTION_P (fn1))
2420 return decls_match (fn1, fn2);
2424 /* Print information about one overload candidate CANDIDATE. MSGSTR
2425 is the text to print before the candidate itself.
2427 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2428 to have been run through gettext by the caller. This wart makes
2429 life simpler in print_z_candidates and for the translators. */
2432 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2434 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2436 if (candidate->num_convs == 3)
2437 inform ("%s %D(%T, %T, %T) <built-in>", msgstr, candidate->fn,
2438 candidate->convs[0]->type,
2439 candidate->convs[1]->type,
2440 candidate->convs[2]->type);
2441 else if (candidate->num_convs == 2)
2442 inform ("%s %D(%T, %T) <built-in>", msgstr, candidate->fn,
2443 candidate->convs[0]->type,
2444 candidate->convs[1]->type);
2446 inform ("%s %D(%T) <built-in>", msgstr, candidate->fn,
2447 candidate->convs[0]->type);
2449 else if (TYPE_P (candidate->fn))
2450 inform ("%s %T <conversion>", msgstr, candidate->fn);
2451 else if (candidate->viable == -1)
2452 inform ("%s %+#D <near match>", msgstr, candidate->fn);
2454 inform ("%s %+#D", msgstr, candidate->fn);
2458 print_z_candidates (struct z_candidate *candidates)
2461 struct z_candidate *cand1;
2462 struct z_candidate **cand2;
2464 /* There may be duplicates in the set of candidates. We put off
2465 checking this condition as long as possible, since we have no way
2466 to eliminate duplicates from a set of functions in less than n^2
2467 time. Now we are about to emit an error message, so it is more
2468 permissible to go slowly. */
2469 for (cand1 = candidates; cand1; cand1 = cand1->next)
2471 tree fn = cand1->fn;
2472 /* Skip builtin candidates and conversion functions. */
2473 if (TREE_CODE (fn) != FUNCTION_DECL)
2475 cand2 = &cand1->next;
2478 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
2479 && equal_functions (fn, (*cand2)->fn))
2480 *cand2 = (*cand2)->next;
2482 cand2 = &(*cand2)->next;
2489 str = _("candidates are:");
2490 print_z_candidate (str, candidates);
2491 if (candidates->next)
2493 /* Indent successive candidates by the width of the translation
2494 of the above string. */
2495 size_t len = gcc_gettext_width (str) + 1;
2496 char *spaces = (char *) alloca (len);
2497 memset (spaces, ' ', len-1);
2498 spaces[len - 1] = '\0';
2500 candidates = candidates->next;
2503 print_z_candidate (spaces, candidates);
2504 candidates = candidates->next;
2510 /* USER_SEQ is a user-defined conversion sequence, beginning with a
2511 USER_CONV. STD_SEQ is the standard conversion sequence applied to
2512 the result of the conversion function to convert it to the final
2513 desired type. Merge the two sequences into a single sequence,
2514 and return the merged sequence. */
2517 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
2521 gcc_assert (user_seq->kind == ck_user);
2523 /* Find the end of the second conversion sequence. */
2525 while ((*t)->kind != ck_identity)
2526 t = &((*t)->u.next);
2528 /* Replace the identity conversion with the user conversion
2532 /* The entire sequence is a user-conversion sequence. */
2533 std_seq->user_conv_p = true;
2538 /* Returns the best overload candidate to perform the requested
2539 conversion. This function is used for three the overloading situations
2540 described in [over.match.copy], [over.match.conv], and [over.match.ref].
2541 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
2542 per [dcl.init.ref], so we ignore temporary bindings. */
2544 static struct z_candidate *
2545 build_user_type_conversion_1 (tree totype, tree expr, int flags)
2547 struct z_candidate *candidates, *cand;
2548 tree fromtype = TREE_TYPE (expr);
2549 tree ctors = NULL_TREE;
2550 tree conv_fns = NULL_TREE;
2551 conversion *conv = NULL;
2552 tree args = NULL_TREE;
2555 /* We represent conversion within a hierarchy using RVALUE_CONV and
2556 BASE_CONV, as specified by [over.best.ics]; these become plain
2557 constructor calls, as specified in [dcl.init]. */
2558 gcc_assert (!IS_AGGR_TYPE (fromtype) || !IS_AGGR_TYPE (totype)
2559 || !DERIVED_FROM_P (totype, fromtype));
2561 if (IS_AGGR_TYPE (totype))
2562 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
2564 if (IS_AGGR_TYPE (fromtype))
2565 conv_fns = lookup_conversions (fromtype);
2568 flags |= LOOKUP_NO_CONVERSION;
2574 ctors = BASELINK_FUNCTIONS (ctors);
2576 t = build_int_cst (build_pointer_type (totype), 0);
2577 args = build_tree_list (NULL_TREE, expr);
2578 /* We should never try to call the abstract or base constructor
2580 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
2581 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
2582 args = tree_cons (NULL_TREE, t, args);
2584 for (; ctors; ctors = OVL_NEXT (ctors))
2586 tree ctor = OVL_CURRENT (ctors);
2587 if (DECL_NONCONVERTING_P (ctor))
2590 if (TREE_CODE (ctor) == TEMPLATE_DECL)
2591 cand = add_template_candidate (&candidates, ctor, totype,
2592 NULL_TREE, args, NULL_TREE,
2593 TYPE_BINFO (totype),
2594 TYPE_BINFO (totype),
2598 cand = add_function_candidate (&candidates, ctor, totype,
2599 args, TYPE_BINFO (totype),
2600 TYPE_BINFO (totype),
2604 cand->second_conv = build_identity_conv (totype, NULL_TREE);
2608 args = build_tree_list (NULL_TREE, build_this (expr));
2610 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
2613 tree conversion_path = TREE_PURPOSE (conv_fns);
2614 int convflags = LOOKUP_NO_CONVERSION;
2616 /* If we are called to convert to a reference type, we are trying to
2617 find an lvalue binding, so don't even consider temporaries. If
2618 we don't find an lvalue binding, the caller will try again to
2619 look for a temporary binding. */
2620 if (TREE_CODE (totype) == REFERENCE_TYPE)
2621 convflags |= LOOKUP_NO_TEMP_BIND;
2623 for (fns = TREE_VALUE (conv_fns); fns; fns = OVL_NEXT (fns))
2625 tree fn = OVL_CURRENT (fns);
2627 /* [over.match.funcs] For conversion functions, the function
2628 is considered to be a member of the class of the implicit
2629 object argument for the purpose of defining the type of
2630 the implicit object parameter.
2632 So we pass fromtype as CTYPE to add_*_candidate. */
2634 if (TREE_CODE (fn) == TEMPLATE_DECL)
2635 cand = add_template_candidate (&candidates, fn, fromtype,
2638 TYPE_BINFO (fromtype),
2643 cand = add_function_candidate (&candidates, fn, fromtype,
2645 TYPE_BINFO (fromtype),
2652 = implicit_conversion (totype,
2653 TREE_TYPE (TREE_TYPE (cand->fn)),
2655 /*c_cast_p=*/false, convflags);
2657 cand->second_conv = ics;
2661 else if (candidates->viable == 1 && ics->bad_p)
2667 candidates = splice_viable (candidates, pedantic, &any_viable_p);
2671 cand = tourney (candidates);
2674 if (flags & LOOKUP_COMPLAIN)
2676 error ("conversion from %qT to %qT is ambiguous",
2678 print_z_candidates (candidates);
2681 cand = candidates; /* any one will do */
2682 cand->second_conv = build_ambiguous_conv (totype, expr);
2683 cand->second_conv->user_conv_p = true;
2684 if (!any_strictly_viable (candidates))
2685 cand->second_conv->bad_p = true;
2686 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
2687 ambiguous conversion is no worse than another user-defined
2693 /* Build the user conversion sequence. */
2696 (DECL_CONSTRUCTOR_P (cand->fn)
2697 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
2698 build_identity_conv (TREE_TYPE (expr), expr));
2701 /* Combine it with the second conversion sequence. */
2702 cand->second_conv = merge_conversion_sequences (conv,
2705 if (cand->viable == -1)
2706 cand->second_conv->bad_p = true;
2712 build_user_type_conversion (tree totype, tree expr, int flags)
2714 struct z_candidate *cand
2715 = build_user_type_conversion_1 (totype, expr, flags);
2719 if (cand->second_conv->kind == ck_ambig)
2720 return error_mark_node;
2721 expr = convert_like (cand->second_conv, expr);
2722 return convert_from_reference (expr);
2727 /* Do any initial processing on the arguments to a function call. */
2730 resolve_args (tree args)
2733 for (t = args; t; t = TREE_CHAIN (t))
2735 tree arg = TREE_VALUE (t);
2737 if (error_operand_p (arg))
2738 return error_mark_node;
2739 else if (VOID_TYPE_P (TREE_TYPE (arg)))
2741 error ("invalid use of void expression");
2742 return error_mark_node;
2744 else if (invalid_nonstatic_memfn_p (arg))
2745 return error_mark_node;
2750 /* Perform overload resolution on FN, which is called with the ARGS.
2752 Return the candidate function selected by overload resolution, or
2753 NULL if the event that overload resolution failed. In the case
2754 that overload resolution fails, *CANDIDATES will be the set of
2755 candidates considered, and ANY_VIABLE_P will be set to true or
2756 false to indicate whether or not any of the candidates were
2759 The ARGS should already have gone through RESOLVE_ARGS before this
2760 function is called. */
2762 static struct z_candidate *
2763 perform_overload_resolution (tree fn,
2765 struct z_candidate **candidates,
2768 struct z_candidate *cand;
2769 tree explicit_targs = NULL_TREE;
2770 int template_only = 0;
2773 *any_viable_p = true;
2775 /* Check FN and ARGS. */
2776 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
2777 || TREE_CODE (fn) == TEMPLATE_DECL
2778 || TREE_CODE (fn) == OVERLOAD
2779 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
2780 gcc_assert (!args || TREE_CODE (args) == TREE_LIST);
2782 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2784 explicit_targs = TREE_OPERAND (fn, 1);
2785 fn = TREE_OPERAND (fn, 0);
2789 /* Add the various candidate functions. */
2790 add_candidates (fn, args, explicit_targs, template_only,
2791 /*conversion_path=*/NULL_TREE,
2792 /*access_path=*/NULL_TREE,
2796 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
2800 cand = tourney (*candidates);
2804 /* Return an expression for a call to FN (a namespace-scope function,
2805 or a static member function) with the ARGS. */
2808 build_new_function_call (tree fn, tree args, bool koenig_p)
2810 struct z_candidate *candidates, *cand;
2815 args = resolve_args (args);
2816 if (args == error_mark_node)
2817 return error_mark_node;
2819 /* If this function was found without using argument dependent
2820 lookup, then we want to ignore any undeclared friend
2826 fn = remove_hidden_names (fn);
2829 error ("no matching function for call to %<%D(%A)%>",
2830 DECL_NAME (OVL_CURRENT (orig_fn)), args);
2831 return error_mark_node;
2835 /* Get the high-water mark for the CONVERSION_OBSTACK. */
2836 p = conversion_obstack_alloc (0);
2838 cand = perform_overload_resolution (fn, args, &candidates, &any_viable_p);
2842 if (!any_viable_p && candidates && ! candidates->next)
2843 return build_function_call (candidates->fn, args);
2844 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
2845 fn = TREE_OPERAND (fn, 0);
2847 error ("no matching function for call to %<%D(%A)%>",
2848 DECL_NAME (OVL_CURRENT (fn)), args);
2850 error ("call of overloaded %<%D(%A)%> is ambiguous",
2851 DECL_NAME (OVL_CURRENT (fn)), args);
2853 print_z_candidates (candidates);
2854 result = error_mark_node;
2857 result = build_over_call (cand, LOOKUP_NORMAL);
2859 /* Free all the conversions we allocated. */
2860 obstack_free (&conversion_obstack, p);
2865 /* Build a call to a global operator new. FNNAME is the name of the
2866 operator (either "operator new" or "operator new[]") and ARGS are
2867 the arguments provided. *SIZE points to the total number of bytes
2868 required by the allocation, and is updated if that is changed here.
2869 *COOKIE_SIZE is non-NULL if a cookie should be used. If this
2870 function determines that no cookie should be used, after all,
2871 *COOKIE_SIZE is set to NULL_TREE. If FN is non-NULL, it will be
2872 set, upon return, to the allocation function called. */
2875 build_operator_new_call (tree fnname, tree args,
2876 tree *size, tree *cookie_size,
2880 struct z_candidate *candidates;
2881 struct z_candidate *cand;
2886 args = tree_cons (NULL_TREE, *size, args);
2887 args = resolve_args (args);
2888 if (args == error_mark_node)
2895 If this lookup fails to find the name, or if the allocated type
2896 is not a class type, the allocation function's name is looked
2897 up in the global scope.
2899 we disregard block-scope declarations of "operator new". */
2900 fns = lookup_function_nonclass (fnname, args, /*block_p=*/false);
2902 /* Figure out what function is being called. */
2903 cand = perform_overload_resolution (fns, args, &candidates, &any_viable_p);
2905 /* If no suitable function could be found, issue an error message
2910 error ("no matching function for call to %<%D(%A)%>",
2911 DECL_NAME (OVL_CURRENT (fns)), args);
2913 error ("call of overloaded %<%D(%A)%> is ambiguous",
2914 DECL_NAME (OVL_CURRENT (fns)), args);
2916 print_z_candidates (candidates);
2917 return error_mark_node;
2920 /* If a cookie is required, add some extra space. Whether
2921 or not a cookie is required cannot be determined until
2922 after we know which function was called. */
2925 bool use_cookie = true;
2926 if (!abi_version_at_least (2))
2928 tree placement = TREE_CHAIN (args);
2929 /* In G++ 3.2, the check was implemented incorrectly; it
2930 looked at the placement expression, rather than the
2931 type of the function. */
2932 if (placement && !TREE_CHAIN (placement)
2933 && same_type_p (TREE_TYPE (TREE_VALUE (placement)),
2941 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
2942 /* Skip the size_t parameter. */
2943 arg_types = TREE_CHAIN (arg_types);
2944 /* Check the remaining parameters (if any). */
2946 && TREE_CHAIN (arg_types) == void_list_node
2947 && same_type_p (TREE_VALUE (arg_types),
2951 /* If we need a cookie, adjust the number of bytes allocated. */
2954 /* Update the total size. */
2955 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
2956 /* Update the argument list to reflect the adjusted size. */
2957 TREE_VALUE (args) = *size;
2960 *cookie_size = NULL_TREE;
2963 /* Tell our caller which function we decided to call. */
2967 /* Build the CALL_EXPR. */
2968 return build_over_call (cand, LOOKUP_NORMAL);
2972 build_object_call (tree obj, tree args)
2974 struct z_candidate *candidates = 0, *cand;
2975 tree fns, convs, mem_args = NULL_TREE;
2976 tree type = TREE_TYPE (obj);
2978 tree result = NULL_TREE;
2981 if (TYPE_PTRMEMFUNC_P (type))
2983 /* It's no good looking for an overloaded operator() on a
2984 pointer-to-member-function. */
2985 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
2986 return error_mark_node;
2989 if (TYPE_BINFO (type))
2991 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
2992 if (fns == error_mark_node)
2993 return error_mark_node;
2998 args = resolve_args (args);
3000 if (args == error_mark_node)
3001 return error_mark_node;
3003 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3004 p = conversion_obstack_alloc (0);
3008 tree base = BINFO_TYPE (BASELINK_BINFO (fns));
3009 mem_args = tree_cons (NULL_TREE, build_this (obj), args);
3011 for (fns = BASELINK_FUNCTIONS (fns); fns; fns = OVL_NEXT (fns))
3013 tree fn = OVL_CURRENT (fns);
3014 if (TREE_CODE (fn) == TEMPLATE_DECL)
3015 add_template_candidate (&candidates, fn, base, NULL_TREE,
3016 mem_args, NULL_TREE,
3019 LOOKUP_NORMAL, DEDUCE_CALL);
3021 add_function_candidate
3022 (&candidates, fn, base, mem_args, TYPE_BINFO (type),
3023 TYPE_BINFO (type), LOOKUP_NORMAL);
3027 convs = lookup_conversions (type);
3029 for (; convs; convs = TREE_CHAIN (convs))
3031 tree fns = TREE_VALUE (convs);
3032 tree totype = TREE_TYPE (TREE_TYPE (OVL_CURRENT (fns)));
3034 if ((TREE_CODE (totype) == POINTER_TYPE
3035 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3036 || (TREE_CODE (totype) == REFERENCE_TYPE
3037 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3038 || (TREE_CODE (totype) == REFERENCE_TYPE
3039 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3040 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3041 for (; fns; fns = OVL_NEXT (fns))
3043 tree fn = OVL_CURRENT (fns);
3044 if (TREE_CODE (fn) == TEMPLATE_DECL)
3045 add_template_conv_candidate
3046 (&candidates, fn, obj, args, totype,
3047 /*access_path=*/NULL_TREE,
3048 /*conversion_path=*/NULL_TREE);
3050 add_conv_candidate (&candidates, fn, obj, args,
3051 /*conversion_path=*/NULL_TREE,
3052 /*access_path=*/NULL_TREE);
3056 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3059 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj), args);
3060 print_z_candidates (candidates);
3061 result = error_mark_node;
3065 cand = tourney (candidates);
3068 error ("call of %<(%T) (%A)%> is ambiguous", TREE_TYPE (obj), args);
3069 print_z_candidates (candidates);
3070 result = error_mark_node;
3072 /* Since cand->fn will be a type, not a function, for a conversion
3073 function, we must be careful not to unconditionally look at
3075 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3076 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3077 result = build_over_call (cand, LOOKUP_NORMAL);
3080 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1);
3081 obj = convert_from_reference (obj);
3082 result = build_function_call (obj, args);
3086 /* Free all the conversions we allocated. */
3087 obstack_free (&conversion_obstack, p);
3093 op_error (enum tree_code code, enum tree_code code2,
3094 tree arg1, tree arg2, tree arg3, const char *problem)
3098 if (code == MODIFY_EXPR)
3099 opname = assignment_operator_name_info[code2].name;
3101 opname = operator_name_info[code].name;
3106 error ("%s for ternary %<operator?:%> in %<%E ? %E : %E%>",
3107 problem, arg1, arg2, arg3);
3110 case POSTINCREMENT_EXPR:
3111 case POSTDECREMENT_EXPR:
3112 error ("%s for %<operator%s%> in %<%E%s%>", problem, opname, arg1, opname);
3116 error ("%s for %<operator[]%> in %<%E[%E]%>", problem, arg1, arg2);
3121 error ("%s for %qs in %<%s %E%>", problem, opname, opname, arg1);
3126 error ("%s for %<operator%s%> in %<%E %s %E%>",
3127 problem, opname, arg1, opname, arg2);
3129 error ("%s for %<operator%s%> in %<%s%E%>",
3130 problem, opname, opname, arg1);
3135 /* Return the implicit conversion sequence that could be used to
3136 convert E1 to E2 in [expr.cond]. */
3139 conditional_conversion (tree e1, tree e2)
3141 tree t1 = non_reference (TREE_TYPE (e1));
3142 tree t2 = non_reference (TREE_TYPE (e2));
3148 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3149 implicitly converted (clause _conv_) to the type "reference to
3150 T2", subject to the constraint that in the conversion the
3151 reference must bind directly (_dcl.init.ref_) to E1. */
3152 if (real_lvalue_p (e2))
3154 conv = implicit_conversion (build_reference_type (t2),
3158 LOOKUP_NO_TEMP_BIND);
3165 If E1 and E2 have class type, and the underlying class types are
3166 the same or one is a base class of the other: E1 can be converted
3167 to match E2 if the class of T2 is the same type as, or a base
3168 class of, the class of T1, and the cv-qualification of T2 is the
3169 same cv-qualification as, or a greater cv-qualification than, the
3170 cv-qualification of T1. If the conversion is applied, E1 is
3171 changed to an rvalue of type T2 that still refers to the original
3172 source class object (or the appropriate subobject thereof). */
3173 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3174 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3176 if (good_base && at_least_as_qualified_p (t2, t1))
3178 conv = build_identity_conv (t1, e1);
3179 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3180 TYPE_MAIN_VARIANT (t2)))
3181 conv = build_conv (ck_base, t2, conv);
3183 conv = build_conv (ck_rvalue, t2, conv);
3192 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3193 converted to the type that expression E2 would have if E2 were
3194 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3195 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
3199 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
3200 arguments to the conditional expression. */
3203 build_conditional_expr (tree arg1, tree arg2, tree arg3)
3207 tree result = NULL_TREE;
3208 tree result_type = NULL_TREE;
3209 bool lvalue_p = true;
3210 struct z_candidate *candidates = 0;
3211 struct z_candidate *cand;
3214 /* As a G++ extension, the second argument to the conditional can be
3215 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
3216 c'.) If the second operand is omitted, make sure it is
3217 calculated only once. */
3221 pedwarn ("ISO C++ forbids omitting the middle term of a ?: expression");
3223 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
3224 if (real_lvalue_p (arg1))
3225 arg2 = arg1 = stabilize_reference (arg1);
3227 arg2 = arg1 = save_expr (arg1);
3232 The first expr ession is implicitly converted to bool (clause
3234 arg1 = perform_implicit_conversion (boolean_type_node, arg1);
3236 /* If something has already gone wrong, just pass that fact up the
3238 if (error_operand_p (arg1)
3239 || error_operand_p (arg2)
3240 || error_operand_p (arg3))
3241 return error_mark_node;
3245 If either the second or the third operand has type (possibly
3246 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
3247 array-to-pointer (_conv.array_), and function-to-pointer
3248 (_conv.func_) standard conversions are performed on the second
3249 and third operands. */
3250 arg2_type = unlowered_expr_type (arg2);
3251 arg3_type = unlowered_expr_type (arg3);
3252 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
3254 /* Do the conversions. We don't these for `void' type arguments
3255 since it can't have any effect and since decay_conversion
3256 does not handle that case gracefully. */
3257 if (!VOID_TYPE_P (arg2_type))
3258 arg2 = decay_conversion (arg2);
3259 if (!VOID_TYPE_P (arg3_type))
3260 arg3 = decay_conversion (arg3);
3261 arg2_type = TREE_TYPE (arg2);
3262 arg3_type = TREE_TYPE (arg3);
3266 One of the following shall hold:
3268 --The second or the third operand (but not both) is a
3269 throw-expression (_except.throw_); the result is of the
3270 type of the other and is an rvalue.
3272 --Both the second and the third operands have type void; the
3273 result is of type void and is an rvalue.
3275 We must avoid calling force_rvalue for expressions of type
3276 "void" because it will complain that their value is being
3278 if (TREE_CODE (arg2) == THROW_EXPR
3279 && TREE_CODE (arg3) != THROW_EXPR)
3281 if (!VOID_TYPE_P (arg3_type))
3282 arg3 = force_rvalue (arg3);
3283 arg3_type = TREE_TYPE (arg3);
3284 result_type = arg3_type;
3286 else if (TREE_CODE (arg2) != THROW_EXPR
3287 && TREE_CODE (arg3) == THROW_EXPR)
3289 if (!VOID_TYPE_P (arg2_type))
3290 arg2 = force_rvalue (arg2);
3291 arg2_type = TREE_TYPE (arg2);
3292 result_type = arg2_type;
3294 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
3295 result_type = void_type_node;
3298 if (VOID_TYPE_P (arg2_type))
3299 error ("second operand to the conditional operator "
3300 "is of type %<void%>, "
3301 "but the third operand is neither a throw-expression "
3302 "nor of type %<void%>");
3304 error ("third operand to the conditional operator "
3305 "is of type %<void%>, "
3306 "but the second operand is neither a throw-expression "
3307 "nor of type %<void%>");
3308 return error_mark_node;
3312 goto valid_operands;
3316 Otherwise, if the second and third operand have different types,
3317 and either has (possibly cv-qualified) class type, an attempt is
3318 made to convert each of those operands to the type of the other. */
3319 else if (!same_type_p (arg2_type, arg3_type)
3320 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3325 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3326 p = conversion_obstack_alloc (0);
3328 conv2 = conditional_conversion (arg2, arg3);
3329 conv3 = conditional_conversion (arg3, arg2);
3333 If both can be converted, or one can be converted but the
3334 conversion is ambiguous, the program is ill-formed. If
3335 neither can be converted, the operands are left unchanged and
3336 further checking is performed as described below. If exactly
3337 one conversion is possible, that conversion is applied to the
3338 chosen operand and the converted operand is used in place of
3339 the original operand for the remainder of this section. */
3340 if ((conv2 && !conv2->bad_p
3341 && conv3 && !conv3->bad_p)
3342 || (conv2 && conv2->kind == ck_ambig)
3343 || (conv3 && conv3->kind == ck_ambig))
3345 error ("operands to ?: have different types %qT and %qT",
3346 arg2_type, arg3_type);
3347 result = error_mark_node;
3349 else if (conv2 && (!conv2->bad_p || !conv3))
3351 arg2 = convert_like (conv2, arg2);
3352 arg2 = convert_from_reference (arg2);
3353 arg2_type = TREE_TYPE (arg2);
3354 /* Even if CONV2 is a valid conversion, the result of the
3355 conversion may be invalid. For example, if ARG3 has type
3356 "volatile X", and X does not have a copy constructor
3357 accepting a "volatile X&", then even if ARG2 can be
3358 converted to X, the conversion will fail. */
3359 if (error_operand_p (arg2))
3360 result = error_mark_node;
3362 else if (conv3 && (!conv3->bad_p || !conv2))
3364 arg3 = convert_like (conv3, arg3);
3365 arg3 = convert_from_reference (arg3);
3366 arg3_type = TREE_TYPE (arg3);
3367 if (error_operand_p (arg3))
3368 result = error_mark_node;
3371 /* Free all the conversions we allocated. */
3372 obstack_free (&conversion_obstack, p);
3377 /* If, after the conversion, both operands have class type,
3378 treat the cv-qualification of both operands as if it were the
3379 union of the cv-qualification of the operands.
3381 The standard is not clear about what to do in this
3382 circumstance. For example, if the first operand has type
3383 "const X" and the second operand has a user-defined
3384 conversion to "volatile X", what is the type of the second
3385 operand after this step? Making it be "const X" (matching
3386 the first operand) seems wrong, as that discards the
3387 qualification without actually performing a copy. Leaving it
3388 as "volatile X" seems wrong as that will result in the
3389 conditional expression failing altogether, even though,
3390 according to this step, the one operand could be converted to
3391 the type of the other. */
3392 if ((conv2 || conv3)
3393 && CLASS_TYPE_P (arg2_type)
3394 && TYPE_QUALS (arg2_type) != TYPE_QUALS (arg3_type))
3395 arg2_type = arg3_type =
3396 cp_build_qualified_type (arg2_type,
3397 TYPE_QUALS (arg2_type)
3398 | TYPE_QUALS (arg3_type));
3403 If the second and third operands are lvalues and have the same
3404 type, the result is of that type and is an lvalue. */
3405 if (real_lvalue_p (arg2)
3406 && real_lvalue_p (arg3)
3407 && same_type_p (arg2_type, arg3_type))
3409 result_type = arg2_type;
3410 goto valid_operands;
3415 Otherwise, the result is an rvalue. If the second and third
3416 operand do not have the same type, and either has (possibly
3417 cv-qualified) class type, overload resolution is used to
3418 determine the conversions (if any) to be applied to the operands
3419 (_over.match.oper_, _over.built_). */
3421 if (!same_type_p (arg2_type, arg3_type)
3422 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
3428 /* Rearrange the arguments so that add_builtin_candidate only has
3429 to know about two args. In build_builtin_candidates, the
3430 arguments are unscrambled. */
3434 add_builtin_candidates (&candidates,
3437 ansi_opname (COND_EXPR),
3443 If the overload resolution fails, the program is
3445 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3448 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3449 print_z_candidates (candidates);
3450 return error_mark_node;
3452 cand = tourney (candidates);
3455 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, "no match");
3456 print_z_candidates (candidates);
3457 return error_mark_node;
3462 Otherwise, the conversions thus determined are applied, and
3463 the converted operands are used in place of the original
3464 operands for the remainder of this section. */
3465 conv = cand->convs[0];
3466 arg1 = convert_like (conv, arg1);
3467 conv = cand->convs[1];
3468 arg2 = convert_like (conv, arg2);
3469 conv = cand->convs[2];
3470 arg3 = convert_like (conv, arg3);
3475 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
3476 and function-to-pointer (_conv.func_) standard conversions are
3477 performed on the second and third operands.
3479 We need to force the lvalue-to-rvalue conversion here for class types,
3480 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
3481 that isn't wrapped with a TARGET_EXPR plays havoc with exception
3484 arg2 = force_rvalue (arg2);
3485 if (!CLASS_TYPE_P (arg2_type))
3486 arg2_type = TREE_TYPE (arg2);
3488 arg3 = force_rvalue (arg3);
3489 if (!CLASS_TYPE_P (arg2_type))
3490 arg3_type = TREE_TYPE (arg3);
3492 if (arg2 == error_mark_node || arg3 == error_mark_node)
3493 return error_mark_node;
3497 After those conversions, one of the following shall hold:
3499 --The second and third operands have the same type; the result is of
3501 if (same_type_p (arg2_type, arg3_type))
3502 result_type = arg2_type;
3505 --The second and third operands have arithmetic or enumeration
3506 type; the usual arithmetic conversions are performed to bring
3507 them to a common type, and the result is of that type. */
3508 else if ((ARITHMETIC_TYPE_P (arg2_type)
3509 || TREE_CODE (arg2_type) == ENUMERAL_TYPE)
3510 && (ARITHMETIC_TYPE_P (arg3_type)
3511 || TREE_CODE (arg3_type) == ENUMERAL_TYPE))
3513 /* In this case, there is always a common type. */
3514 result_type = type_after_usual_arithmetic_conversions (arg2_type,
3517 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
3518 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
3519 warning (0, "enumeral mismatch in conditional expression: %qT vs %qT",
3520 arg2_type, arg3_type);
3521 else if (extra_warnings
3522 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
3523 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
3524 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
3525 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
3526 warning (0, "enumeral and non-enumeral type in conditional expression");
3528 arg2 = perform_implicit_conversion (result_type, arg2);
3529 arg3 = perform_implicit_conversion (result_type, arg3);
3533 --The second and third operands have pointer type, or one has
3534 pointer type and the other is a null pointer constant; pointer
3535 conversions (_conv.ptr_) and qualification conversions
3536 (_conv.qual_) are performed to bring them to their composite
3537 pointer type (_expr.rel_). The result is of the composite
3540 --The second and third operands have pointer to member type, or
3541 one has pointer to member type and the other is a null pointer
3542 constant; pointer to member conversions (_conv.mem_) and
3543 qualification conversions (_conv.qual_) are performed to bring
3544 them to a common type, whose cv-qualification shall match the
3545 cv-qualification of either the second or the third operand.
3546 The result is of the common type. */
3547 else if ((null_ptr_cst_p (arg2)
3548 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
3549 || (null_ptr_cst_p (arg3)
3550 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
3551 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
3552 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
3553 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
3555 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
3556 arg3, "conditional expression");
3557 if (result_type == error_mark_node)
3558 return error_mark_node;
3559 arg2 = perform_implicit_conversion (result_type, arg2);
3560 arg3 = perform_implicit_conversion (result_type, arg3);
3565 error ("operands to ?: have different types %qT and %qT",
3566 arg2_type, arg3_type);
3567 return error_mark_node;
3571 result = fold_if_not_in_template (build3 (COND_EXPR, result_type, arg1,
3573 /* We can't use result_type below, as fold might have returned a
3578 /* Expand both sides into the same slot, hopefully the target of
3579 the ?: expression. We used to check for TARGET_EXPRs here,
3580 but now we sometimes wrap them in NOP_EXPRs so the test would
3582 if (CLASS_TYPE_P (TREE_TYPE (result)))
3583 result = get_target_expr (result);
3584 /* If this expression is an rvalue, but might be mistaken for an
3585 lvalue, we must add a NON_LVALUE_EXPR. */
3586 result = rvalue (result);
3592 /* OPERAND is an operand to an expression. Perform necessary steps
3593 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
3597 prep_operand (tree operand)
3601 if (CLASS_TYPE_P (TREE_TYPE (operand))
3602 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
3603 /* Make sure the template type is instantiated now. */
3604 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
3610 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
3611 OVERLOAD) to the CANDIDATES, returning an updated list of
3612 CANDIDATES. The ARGS are the arguments provided to the call,
3613 without any implicit object parameter. The EXPLICIT_TARGS are
3614 explicit template arguments provided. TEMPLATE_ONLY is true if
3615 only template functions should be considered. CONVERSION_PATH,
3616 ACCESS_PATH, and FLAGS are as for add_function_candidate. */
3619 add_candidates (tree fns, tree args,
3620 tree explicit_targs, bool template_only,
3621 tree conversion_path, tree access_path,
3623 struct z_candidate **candidates)
3626 tree non_static_args;
3628 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
3629 /* Delay creating the implicit this parameter until it is needed. */
3630 non_static_args = NULL_TREE;
3637 fn = OVL_CURRENT (fns);
3638 /* Figure out which set of arguments to use. */
3639 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
3641 /* If this function is a non-static member, prepend the implicit
3642 object parameter. */
3643 if (!non_static_args)
3644 non_static_args = tree_cons (NULL_TREE,
3645 build_this (TREE_VALUE (args)),
3647 fn_args = non_static_args;
3650 /* Otherwise, just use the list of arguments provided. */
3653 if (TREE_CODE (fn) == TEMPLATE_DECL)
3654 add_template_candidate (candidates,
3664 else if (!template_only)
3665 add_function_candidate (candidates,
3672 fns = OVL_NEXT (fns);
3677 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
3680 struct z_candidate *candidates = 0, *cand;
3681 tree arglist, fnname;
3683 tree result = NULL_TREE;
3684 bool result_valid_p = false;
3685 enum tree_code code2 = NOP_EXPR;
3690 bool expl_eq_arg1 = false;
3692 if (error_operand_p (arg1)
3693 || error_operand_p (arg2)
3694 || error_operand_p (arg3))
3695 return error_mark_node;
3697 if (code == MODIFY_EXPR)
3699 code2 = TREE_CODE (arg3);
3701 fnname = ansi_assopname (code2);
3704 fnname = ansi_opname (code);
3706 arg1 = prep_operand (arg1);
3712 case VEC_DELETE_EXPR:
3714 /* Use build_op_new_call and build_op_delete_call instead. */
3718 return build_object_call (arg1, arg2);
3720 case TRUTH_ORIF_EXPR:
3721 case TRUTH_ANDIF_EXPR:
3722 case TRUTH_AND_EXPR:
3724 if (COMPARISON_CLASS_P (arg1))
3725 expl_eq_arg1 = true;
3730 arg2 = prep_operand (arg2);
3731 arg3 = prep_operand (arg3);
3733 if (code == COND_EXPR)
3735 if (arg2 == NULL_TREE
3736 || TREE_CODE (TREE_TYPE (arg2)) == VOID_TYPE
3737 || TREE_CODE (TREE_TYPE (arg3)) == VOID_TYPE
3738 || (! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))
3739 && ! IS_OVERLOAD_TYPE (TREE_TYPE (arg3))))
3742 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
3743 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
3746 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
3747 arg2 = integer_zero_node;
3749 arglist = NULL_TREE;
3751 arglist = tree_cons (NULL_TREE, arg3, arglist);
3753 arglist = tree_cons (NULL_TREE, arg2, arglist);
3754 arglist = tree_cons (NULL_TREE, arg1, arglist);
3756 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3757 p = conversion_obstack_alloc (0);
3759 /* Add namespace-scope operators to the list of functions to
3761 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
3762 arglist, NULL_TREE, false, NULL_TREE, NULL_TREE,
3763 flags, &candidates);
3764 /* Add class-member operators to the candidate set. */
3765 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
3769 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
3770 if (fns == error_mark_node)
3772 result = error_mark_node;
3773 goto user_defined_result_ready;
3776 add_candidates (BASELINK_FUNCTIONS (fns), arglist,
3778 BASELINK_BINFO (fns),
3779 TYPE_BINFO (TREE_TYPE (arg1)),
3780 flags, &candidates);
3783 /* Rearrange the arguments for ?: so that add_builtin_candidate only has
3784 to know about two args; a builtin candidate will always have a first
3785 parameter of type bool. We'll handle that in
3786 build_builtin_candidate. */
3787 if (code == COND_EXPR)
3797 args[2] = NULL_TREE;
3800 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
3806 /* For these, the built-in candidates set is empty
3807 [over.match.oper]/3. We don't want non-strict matches
3808 because exact matches are always possible with built-in
3809 operators. The built-in candidate set for COMPONENT_REF
3810 would be empty too, but since there are no such built-in
3811 operators, we accept non-strict matches for them. */
3816 strict_p = pedantic;
3820 candidates = splice_viable (candidates, strict_p, &any_viable_p);
3825 case POSTINCREMENT_EXPR:
3826 case POSTDECREMENT_EXPR:
3827 /* Look for an `operator++ (int)'. If they didn't have
3828 one, then we fall back to the old way of doing things. */
3829 if (flags & LOOKUP_COMPLAIN)
3830 pedwarn ("no %<%D(int)%> declared for postfix %qs, "
3831 "trying prefix operator instead",
3833 operator_name_info[code].name);
3834 if (code == POSTINCREMENT_EXPR)
3835 code = PREINCREMENT_EXPR;
3837 code = PREDECREMENT_EXPR;
3838 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
3842 /* The caller will deal with these. */
3847 result_valid_p = true;
3851 if (flags & LOOKUP_COMPLAIN)
3853 op_error (code, code2, arg1, arg2, arg3, "no match");
3854 print_z_candidates (candidates);
3856 result = error_mark_node;
3862 cand = tourney (candidates);
3865 if (flags & LOOKUP_COMPLAIN)
3867 op_error (code, code2, arg1, arg2, arg3, "ambiguous overload");
3868 print_z_candidates (candidates);
3870 result = error_mark_node;
3872 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
3875 *overloaded_p = true;
3877 result = build_over_call (cand, LOOKUP_NORMAL);
3881 /* Give any warnings we noticed during overload resolution. */
3884 struct candidate_warning *w;
3885 for (w = cand->warnings; w; w = w->next)
3886 joust (cand, w->loser, 1);
3889 /* Check for comparison of different enum types. */
3898 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
3899 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
3900 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
3901 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2))))
3903 warning (0, "comparison between %q#T and %q#T",
3904 TREE_TYPE (arg1), TREE_TYPE (arg2));
3911 /* We need to strip any leading REF_BIND so that bitfields
3912 don't cause errors. This should not remove any important
3913 conversions, because builtins don't apply to class
3914 objects directly. */
3915 conv = cand->convs[0];
3916 if (conv->kind == ck_ref_bind)
3917 conv = conv->u.next;
3918 arg1 = convert_like (conv, arg1);
3921 conv = cand->convs[1];
3922 if (conv->kind == ck_ref_bind)
3923 conv = conv->u.next;
3924 arg2 = convert_like (conv, arg2);
3928 conv = cand->convs[2];
3929 if (conv->kind == ck_ref_bind)
3930 conv = conv->u.next;
3931 arg3 = convert_like (conv, arg3);
3936 warn_logical_operator (code, arg1, arg2);
3937 expl_eq_arg1 = true;
3942 user_defined_result_ready:
3944 /* Free all the conversions we allocated. */
3945 obstack_free (&conversion_obstack, p);
3947 if (result || result_valid_p)
3954 return build_modify_expr (arg1, code2, arg2);
3957 return build_indirect_ref (arg1, "unary *");
3959 case TRUTH_ANDIF_EXPR:
3960 case TRUTH_ORIF_EXPR:
3961 case TRUTH_AND_EXPR:
3964 warn_logical_operator (code, arg1, arg2);
3968 case TRUNC_DIV_EXPR:
3979 case TRUNC_MOD_EXPR:
3983 return cp_build_binary_op (code, arg1, arg2);
3985 case UNARY_PLUS_EXPR:
3988 case TRUTH_NOT_EXPR:
3989 case PREINCREMENT_EXPR:
3990 case POSTINCREMENT_EXPR:
3991 case PREDECREMENT_EXPR:
3992 case POSTDECREMENT_EXPR:
3995 return build_unary_op (code, arg1, candidates != 0);
3998 return build_array_ref (arg1, arg2);
4001 return build_conditional_expr (arg1, arg2, arg3);
4004 return build_m_component_ref (build_indirect_ref (arg1, NULL), arg2);
4006 /* The caller will deal with these. */
4018 /* Build a call to operator delete. This has to be handled very specially,
4019 because the restrictions on what signatures match are different from all
4020 other call instances. For a normal delete, only a delete taking (void *)
4021 or (void *, size_t) is accepted. For a placement delete, only an exact
4022 match with the placement new is accepted.
4024 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
4025 ADDR is the pointer to be deleted.
4026 SIZE is the size of the memory block to be deleted.
4027 GLOBAL_P is true if the delete-expression should not consider
4028 class-specific delete operators.
4029 PLACEMENT is the corresponding placement new call, or NULL_TREE.
4030 If PLACEMENT is non-NULL, then ALLOC_FN is the allocation function
4031 called to perform the placement new. */
4034 build_op_delete_call (enum tree_code code, tree addr, tree size,
4035 bool global_p, tree placement,
4038 tree fn = NULL_TREE;
4039 tree fns, fnname, argtypes, type;
4042 if (addr == error_mark_node)
4043 return error_mark_node;
4045 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
4047 fnname = ansi_opname (code);
4049 if (CLASS_TYPE_P (type)
4050 && COMPLETE_TYPE_P (complete_type (type))
4054 If the result of the lookup is ambiguous or inaccessible, or if
4055 the lookup selects a placement deallocation function, the
4056 program is ill-formed.
4058 Therefore, we ask lookup_fnfields to complain about ambiguity. */
4060 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
4061 if (fns == error_mark_node)
4062 return error_mark_node;
4067 if (fns == NULL_TREE)
4068 fns = lookup_name_nonclass (fnname);
4070 /* Strip const and volatile from addr. */
4071 addr = cp_convert (ptr_type_node, addr);
4075 /* Get the parameter types for the allocation function that is
4077 gcc_assert (alloc_fn != NULL_TREE);
4078 argtypes = TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (alloc_fn)));
4082 /* First try it without the size argument. */
4083 argtypes = void_list_node;
4086 /* We make two tries at finding a matching `operator delete'. On
4087 the first pass, we look for a one-operator (or placement)
4088 operator delete. If we're not doing placement delete, then on
4089 the second pass we look for a two-argument delete. */
4090 for (pass = 0; pass < (placement ? 1 : 2); ++pass)
4092 /* Go through the `operator delete' functions looking for one
4093 with a matching type. */
4094 for (fn = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
4100 /* The first argument must be "void *". */
4101 t = TYPE_ARG_TYPES (TREE_TYPE (OVL_CURRENT (fn)));
4102 if (!same_type_p (TREE_VALUE (t), ptr_type_node))
4105 /* On the first pass, check the rest of the arguments. */
4111 if (!same_type_p (TREE_VALUE (a), TREE_VALUE (t)))
4119 /* On the second pass, the second argument must be
4122 && same_type_p (TREE_VALUE (t), size_type_node)
4123 && TREE_CHAIN (t) == void_list_node)
4127 /* If we found a match, we're done. */
4132 /* If we have a matching function, call it. */
4135 /* Make sure we have the actual function, and not an
4137 fn = OVL_CURRENT (fn);
4139 /* If the FN is a member function, make sure that it is
4141 if (DECL_CLASS_SCOPE_P (fn))
4142 perform_or_defer_access_check (TYPE_BINFO (type), fn, fn);
4146 /* The placement args might not be suitable for overload
4147 resolution at this point, so build the call directly. */
4148 int nargs = call_expr_nargs (placement);
4149 tree *argarray = (tree *) alloca (nargs * sizeof (tree));
4152 for (i = 1; i < nargs; i++)
4153 argarray[i] = CALL_EXPR_ARG (placement, i);
4155 return build_cxx_call (fn, nargs, argarray);
4161 args = tree_cons (NULL_TREE, addr, NULL_TREE);
4163 args = tree_cons (NULL_TREE, addr,
4164 build_tree_list (NULL_TREE, size));
4165 return build_function_call (fn, args);
4169 /* If we are doing placement delete we do nothing if we don't find a
4170 matching op delete. */
4174 error ("no suitable %<operator %s%> for %qT",
4175 operator_name_info[(int)code].name, type);
4176 return error_mark_node;
4179 /* If the current scope isn't allowed to access DECL along
4180 BASETYPE_PATH, give an error. The most derived class in
4181 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
4182 the declaration to use in the error diagnostic. */
4185 enforce_access (tree basetype_path, tree decl, tree diag_decl)
4187 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
4189 if (!accessible_p (basetype_path, decl, true))
4191 if (TREE_PRIVATE (decl))
4192 error ("%q+#D is private", diag_decl);
4193 else if (TREE_PROTECTED (decl))
4194 error ("%q+#D is protected", diag_decl);
4196 error ("%q+#D is inaccessible", diag_decl);
4197 error ("within this context");
4204 /* Check that a callable constructor to initialize a temporary of
4205 TYPE from an EXPR exists. */
4208 check_constructor_callable (tree type, tree expr)
4210 build_special_member_call (NULL_TREE,
4211 complete_ctor_identifier,
4212 build_tree_list (NULL_TREE, expr),
4214 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING
4215 | LOOKUP_NO_CONVERSION
4216 | LOOKUP_CONSTRUCTOR_CALLABLE);
4219 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
4220 bitwise or of LOOKUP_* values. If any errors are warnings are
4221 generated, set *DIAGNOSTIC_FN to "error" or "warning",
4222 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
4226 build_temp (tree expr, tree type, int flags,
4227 diagnostic_fn_t *diagnostic_fn)
4231 savew = warningcount, savee = errorcount;
4232 expr = build_special_member_call (NULL_TREE,
4233 complete_ctor_identifier,
4234 build_tree_list (NULL_TREE, expr),
4236 if (warningcount > savew)
4237 *diagnostic_fn = warning0;
4238 else if (errorcount > savee)
4239 *diagnostic_fn = error;
4241 *diagnostic_fn = NULL;
4245 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
4246 EXPR is implicitly converted to type TOTYPE.
4247 FN and ARGNUM are used for diagnostics. */
4250 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
4252 tree t = non_reference (totype);
4254 /* Issue warnings about peculiar, but valid, uses of NULL. */
4255 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
4258 warning (OPT_Wconversion, "passing NULL to non-pointer argument %P of %qD",
4261 warning (OPT_Wconversion, "converting to non-pointer type %qT from NULL", t);
4264 /* Issue warnings if "false" is converted to a NULL pointer */
4265 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
4266 warning (OPT_Wconversion,
4267 "converting %<false%> to pointer type for argument %P of %qD",
4271 /* Perform the conversions in CONVS on the expression EXPR. FN and
4272 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
4273 indicates the `this' argument of a method. INNER is nonzero when
4274 being called to continue a conversion chain. It is negative when a
4275 reference binding will be applied, positive otherwise. If
4276 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
4277 conversions will be emitted if appropriate. If C_CAST_P is true,
4278 this conversion is coming from a C-style cast; in that case,
4279 conversions to inaccessible bases are permitted. */
4282 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
4283 int inner, bool issue_conversion_warnings,
4286 tree totype = convs->type;
4287 diagnostic_fn_t diagnostic_fn;
4290 && convs->kind != ck_user
4291 && convs->kind != ck_ambig
4292 && convs->kind != ck_ref_bind)
4294 conversion *t = convs;
4295 for (; t; t = convs->u.next)
4297 if (t->kind == ck_user || !t->bad_p)
4299 expr = convert_like_real (t, expr, fn, argnum, 1,
4300 /*issue_conversion_warnings=*/false,
4301 /*c_cast_p=*/false);
4304 else if (t->kind == ck_ambig)
4305 return convert_like_real (t, expr, fn, argnum, 1,
4306 /*issue_conversion_warnings=*/false,
4307 /*c_cast_p=*/false);
4308 else if (t->kind == ck_identity)
4311 pedwarn ("invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
4313 pedwarn (" initializing argument %P of %qD", argnum, fn);
4314 return cp_convert (totype, expr);
4317 if (issue_conversion_warnings)
4318 conversion_null_warnings (totype, expr, fn, argnum);
4320 switch (convs->kind)
4324 struct z_candidate *cand = convs->cand;
4325 tree convfn = cand->fn;
4328 if (DECL_CONSTRUCTOR_P (convfn))
4330 tree t = build_int_cst (build_pointer_type (DECL_CONTEXT (convfn)),
4333 args = build_tree_list (NULL_TREE, expr);
4334 /* We should never try to call the abstract or base constructor
4336 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (convfn)
4337 && !DECL_HAS_VTT_PARM_P (convfn));
4338 args = tree_cons (NULL_TREE, t, args);
4341 args = build_this (expr);
4342 expr = build_over_call (cand, LOOKUP_NORMAL);
4344 /* If this is a constructor or a function returning an aggr type,
4345 we need to build up a TARGET_EXPR. */
4346 if (DECL_CONSTRUCTOR_P (convfn))
4347 expr = build_cplus_new (totype, expr);
4349 /* The result of the call is then used to direct-initialize the object
4350 that is the destination of the copy-initialization. [dcl.init]
4352 Note that this step is not reflected in the conversion sequence;
4353 it affects the semantics when we actually perform the
4354 conversion, but is not considered during overload resolution.
4356 If the target is a class, that means call a ctor. */
4357 if (IS_AGGR_TYPE (totype)
4358 && (inner >= 0 || !lvalue_p (expr)))
4362 /* Core issue 84, now a DR, says that we don't
4363 allow UDCs for these args (which deliberately
4364 breaks copy-init of an auto_ptr<Base> from an
4365 auto_ptr<Derived>). */
4366 LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING|LOOKUP_NO_CONVERSION,
4373 (" initializing argument %P of %qD from result of %qD",
4374 argnum, fn, convfn);
4377 (" initializing temporary from result of %qD", convfn);
4379 expr = build_cplus_new (totype, expr);
4384 if (type_unknown_p (expr))
4385 expr = instantiate_type (totype, expr, tf_warning_or_error);
4386 /* Convert a constant to its underlying value, unless we are
4387 about to bind it to a reference, in which case we need to
4388 leave it as an lvalue. */
4390 expr = decl_constant_value (expr);
4391 if (convs->check_copy_constructor_p)
4392 check_constructor_callable (totype, expr);
4395 /* Call build_user_type_conversion again for the error. */
4396 return build_user_type_conversion
4397 (totype, convs->u.expr, LOOKUP_NORMAL);
4403 expr = convert_like_real (convs->u.next, expr, fn, argnum,
4404 convs->kind == ck_ref_bind ? -1 : 1,
4405 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
4407 if (expr == error_mark_node)
4408 return error_mark_node;
4410 switch (convs->kind)
4413 expr = convert_bitfield_to_declared_type (expr);
4414 if (! IS_AGGR_TYPE (totype))
4416 /* Else fall through. */
4418 if (convs->kind == ck_base && !convs->need_temporary_p)
4420 /* We are going to bind a reference directly to a base-class
4421 subobject of EXPR. */
4422 if (convs->check_copy_constructor_p)
4423 check_constructor_callable (TREE_TYPE (expr), expr);
4424 /* Build an expression for `*((base*) &expr)'. */
4425 expr = build_unary_op (ADDR_EXPR, expr, 0);
4426 expr = convert_to_base (expr, build_pointer_type (totype),
4427 !c_cast_p, /*nonnull=*/true);
4428 expr = build_indirect_ref (expr, "implicit conversion");
4432 /* Copy-initialization where the cv-unqualified version of the source
4433 type is the same class as, or a derived class of, the class of the
4434 destination [is treated as direct-initialization]. [dcl.init] */
4435 expr = build_temp (expr, totype, LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING,
4437 if (diagnostic_fn && fn)
4438 diagnostic_fn (" initializing argument %P of %qD", argnum, fn);
4439 return build_cplus_new (totype, expr);
4443 tree ref_type = totype;
4445 /* If necessary, create a temporary. */
4446 if (convs->need_temporary_p || !lvalue_p (expr))
4448 tree type = convs->u.next->type;
4449 cp_lvalue_kind lvalue = real_lvalue_p (expr);
4451 if (!CP_TYPE_CONST_NON_VOLATILE_P (TREE_TYPE (ref_type)))
4453 /* If the reference is volatile or non-const, we
4454 cannot create a temporary. */
4455 if (lvalue & clk_bitfield)
4456 error ("cannot bind bitfield %qE to %qT",
4458 else if (lvalue & clk_packed)
4459 error ("cannot bind packed field %qE to %qT",
4462 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
4463 return error_mark_node;
4465 /* If the source is a packed field, and we must use a copy
4466 constructor, then building the target expr will require
4467 binding the field to the reference parameter to the
4468 copy constructor, and we'll end up with an infinite
4469 loop. If we can use a bitwise copy, then we'll be
4471 if ((lvalue & clk_packed)
4472 && CLASS_TYPE_P (type)
4473 && !TYPE_HAS_TRIVIAL_INIT_REF (type))
4475 error ("cannot bind packed field %qE to %qT",
4477 return error_mark_node;
4479 expr = build_target_expr_with_type (expr, type);
4482 /* Take the address of the thing to which we will bind the
4484 expr = build_unary_op (ADDR_EXPR, expr, 1);
4485 if (expr == error_mark_node)
4486 return error_mark_node;
4488 /* Convert it to a pointer to the type referred to by the
4489 reference. This will adjust the pointer if a derived to
4490 base conversion is being performed. */
4491 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
4493 /* Convert the pointer to the desired reference type. */
4494 return build_nop (ref_type, expr);
4498 return decay_conversion (expr);
4501 /* Warn about deprecated conversion if appropriate. */
4502 string_conv_p (totype, expr, 1);
4507 expr = convert_to_base (expr, totype, !c_cast_p,
4509 return build_nop (totype, expr);
4512 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
4519 if (issue_conversion_warnings)
4520 expr = convert_and_check (totype, expr);
4522 expr = convert (totype, expr);
4527 /* Build a call to __builtin_trap. */
4530 call_builtin_trap (void)
4532 tree fn = implicit_built_in_decls[BUILT_IN_TRAP];
4534 gcc_assert (fn != NULL);
4535 fn = build_call_n (fn, 0);
4539 /* ARG is being passed to a varargs function. Perform any conversions
4540 required. Return the converted value. */
4543 convert_arg_to_ellipsis (tree arg)
4547 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
4548 standard conversions are performed. */
4549 arg = decay_conversion (arg);
4552 If the argument has integral or enumeration type that is subject
4553 to the integral promotions (_conv.prom_), or a floating point
4554 type that is subject to the floating point promotion
4555 (_conv.fpprom_), the value of the argument is converted to the
4556 promoted type before the call. */
4557 if (TREE_CODE (TREE_TYPE (arg)) == REAL_TYPE
4558 && (TYPE_PRECISION (TREE_TYPE (arg))
4559 < TYPE_PRECISION (double_type_node)))
4560 arg = convert_to_real (double_type_node, arg);
4561 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (arg)))
4562 arg = perform_integral_promotions (arg);
4564 arg = require_complete_type (arg);
4566 if (arg != error_mark_node
4567 && !pod_type_p (TREE_TYPE (arg)))
4569 /* Undefined behavior [expr.call] 5.2.2/7. We used to just warn
4570 here and do a bitwise copy, but now cp_expr_size will abort if we
4572 If the call appears in the context of a sizeof expression,
4573 there is no need to emit a warning, since the expression won't be
4574 evaluated. We keep the builtin_trap just as a safety check. */
4575 if (!skip_evaluation)
4576 warning (0, "cannot pass objects of non-POD type %q#T through %<...%>; "
4577 "call will abort at runtime", TREE_TYPE (arg));
4578 arg = call_builtin_trap ();
4579 arg = build2 (COMPOUND_EXPR, integer_type_node, arg,
4586 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
4589 build_x_va_arg (tree expr, tree type)
4591 if (processing_template_decl)
4592 return build_min (VA_ARG_EXPR, type, expr);
4594 type = complete_type_or_else (type, NULL_TREE);
4596 if (expr == error_mark_node || !type)
4597 return error_mark_node;
4599 if (! pod_type_p (type))
4601 /* Remove reference types so we don't ICE later on. */
4602 tree type1 = non_reference (type);
4603 /* Undefined behavior [expr.call] 5.2.2/7. */
4604 warning (0, "cannot receive objects of non-POD type %q#T through %<...%>; "
4605 "call will abort at runtime", type);
4606 expr = convert (build_pointer_type (type1), null_node);
4607 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr),
4608 call_builtin_trap (), expr);
4609 expr = build_indirect_ref (expr, NULL);
4613 return build_va_arg (expr, type);
4616 /* TYPE has been given to va_arg. Apply the default conversions which
4617 would have happened when passed via ellipsis. Return the promoted
4618 type, or the passed type if there is no change. */
4621 cxx_type_promotes_to (tree type)
4625 /* Perform the array-to-pointer and function-to-pointer
4627 type = type_decays_to (type);
4629 promote = type_promotes_to (type);
4630 if (same_type_p (type, promote))
4636 /* ARG is a default argument expression being passed to a parameter of
4637 the indicated TYPE, which is a parameter to FN. Do any required
4638 conversions. Return the converted value. */
4641 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
4643 /* If the ARG is an unparsed default argument expression, the
4644 conversion cannot be performed. */
4645 if (TREE_CODE (arg) == DEFAULT_ARG)
4647 error ("the default argument for parameter %d of %qD has "
4648 "not yet been parsed",
4650 return error_mark_node;
4653 if (fn && DECL_TEMPLATE_INFO (fn))
4654 arg = tsubst_default_argument (fn, type, arg);
4656 arg = break_out_target_exprs (arg);
4658 if (TREE_CODE (arg) == CONSTRUCTOR)
4660 arg = digest_init (type, arg);
4661 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4662 "default argument", fn, parmnum);
4666 /* We must make a copy of ARG, in case subsequent processing
4667 alters any part of it. For example, during gimplification a
4668 cast of the form (T) &X::f (where "f" is a member function)
4669 will lead to replacing the PTRMEM_CST for &X::f with a
4670 VAR_DECL. We can avoid the copy for constants, since they
4671 are never modified in place. */
4672 if (!CONSTANT_CLASS_P (arg))
4673 arg = unshare_expr (arg);
4674 arg = convert_for_initialization (0, type, arg, LOOKUP_NORMAL,
4675 "default argument", fn, parmnum);
4676 arg = convert_for_arg_passing (type, arg);
4682 /* Returns the type which will really be used for passing an argument of
4686 type_passed_as (tree type)
4688 /* Pass classes with copy ctors by invisible reference. */
4689 if (TREE_ADDRESSABLE (type))
4691 type = build_reference_type (type);
4692 /* There are no other pointers to this temporary. */
4693 type = build_qualified_type (type, TYPE_QUAL_RESTRICT);
4695 else if (targetm.calls.promote_prototypes (type)
4696 && INTEGRAL_TYPE_P (type)
4697 && COMPLETE_TYPE_P (type)
4698 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4699 TYPE_SIZE (integer_type_node)))
4700 type = integer_type_node;
4705 /* Actually perform the appropriate conversion. */
4708 convert_for_arg_passing (tree type, tree val)
4710 if (val == error_mark_node)
4712 /* Pass classes with copy ctors by invisible reference. */
4713 else if (TREE_ADDRESSABLE (type))
4714 val = build1 (ADDR_EXPR, build_reference_type (type), val);
4715 else if (targetm.calls.promote_prototypes (type)
4716 && INTEGRAL_TYPE_P (type)
4717 && COMPLETE_TYPE_P (type)
4718 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
4719 TYPE_SIZE (integer_type_node)))
4720 val = perform_integral_promotions (val);
4721 if (warn_missing_format_attribute)
4723 tree rhstype = TREE_TYPE (val);
4724 const enum tree_code coder = TREE_CODE (rhstype);
4725 const enum tree_code codel = TREE_CODE (type);
4726 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
4728 && check_missing_format_attribute (type, rhstype))
4729 warning (OPT_Wmissing_format_attribute,
4730 "argument of function call might be a candidate for a format attribute");
4735 /* Returns true iff FN is a function with magic varargs, i.e. ones for
4736 which no conversions at all should be done. This is true for some
4737 builtins which don't act like normal functions. */
4740 magic_varargs_p (tree fn)
4742 if (DECL_BUILT_IN (fn))
4743 switch (DECL_FUNCTION_CODE (fn))
4745 case BUILT_IN_CLASSIFY_TYPE:
4746 case BUILT_IN_CONSTANT_P:
4747 case BUILT_IN_NEXT_ARG:
4748 case BUILT_IN_STDARG_START:
4749 case BUILT_IN_VA_START:
4758 /* Subroutine of the various build_*_call functions. Overload resolution
4759 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
4760 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
4761 bitmask of various LOOKUP_* flags which apply to the call itself. */
4764 build_over_call (struct z_candidate *cand, int flags)
4767 tree args = cand->args;
4768 conversion **convs = cand->convs;
4770 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
4779 /* In a template, there is no need to perform all of the work that
4780 is normally done. We are only interested in the type of the call
4781 expression, i.e., the return type of the function. Any semantic
4782 errors will be deferred until the template is instantiated. */
4783 if (processing_template_decl)
4787 return_type = TREE_TYPE (TREE_TYPE (fn));
4788 expr = build_call_list (return_type, fn, args);
4789 if (TREE_THIS_VOLATILE (fn) && cfun)
4790 current_function_returns_abnormally = 1;
4791 if (!VOID_TYPE_P (return_type))
4792 require_complete_type (return_type);
4793 return convert_from_reference (expr);
4796 /* Give any warnings we noticed during overload resolution. */
4799 struct candidate_warning *w;
4800 for (w = cand->warnings; w; w = w->next)
4801 joust (cand, w->loser, 1);
4804 if (DECL_FUNCTION_MEMBER_P (fn))
4806 /* If FN is a template function, two cases must be considered.
4811 template <class T> void f();
4813 template <class T> struct B {
4817 struct C : A, B<int> {
4819 using B<int>::g; // #2
4822 In case #1 where `A::f' is a member template, DECL_ACCESS is
4823 recorded in the primary template but not in its specialization.
4824 We check access of FN using its primary template.
4826 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
4827 because it is a member of class template B, DECL_ACCESS is
4828 recorded in the specialization `B<int>::g'. We cannot use its
4829 primary template because `B<T>::g' and `B<int>::g' may have
4830 different access. */
4831 if (DECL_TEMPLATE_INFO (fn)
4832 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
4833 perform_or_defer_access_check (cand->access_path,
4834 DECL_TI_TEMPLATE (fn), fn);
4836 perform_or_defer_access_check (cand->access_path, fn, fn);
4839 if (args && TREE_CODE (args) != TREE_LIST)
4840 args = build_tree_list (NULL_TREE, args);
4843 /* Find maximum size of vector to hold converted arguments. */
4844 parmlen = list_length (parm);
4845 nargs = list_length (args);
4846 if (parmlen > nargs)
4848 argarray = (tree *) alloca (nargs * sizeof (tree));
4850 /* The implicit parameters to a constructor are not considered by overload
4851 resolution, and must be of the proper type. */
4852 if (DECL_CONSTRUCTOR_P (fn))
4854 argarray[j++] = TREE_VALUE (arg);
4855 arg = TREE_CHAIN (arg);
4856 parm = TREE_CHAIN (parm);
4857 /* We should never try to call the abstract constructor. */
4858 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
4860 if (DECL_HAS_VTT_PARM_P (fn))
4862 argarray[j++] = TREE_VALUE (arg);
4863 arg = TREE_CHAIN (arg);
4864 parm = TREE_CHAIN (parm);
4867 /* Bypass access control for 'this' parameter. */
4868 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
4870 tree parmtype = TREE_VALUE (parm);
4871 tree argtype = TREE_TYPE (TREE_VALUE (arg));
4875 if (convs[i]->bad_p)
4876 pedwarn ("passing %qT as %<this%> argument of %q#D discards qualifiers",
4877 TREE_TYPE (argtype), fn);
4879 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
4880 X is called for an object that is not of type X, or of a type
4881 derived from X, the behavior is undefined.
4883 So we can assume that anything passed as 'this' is non-null, and
4884 optimize accordingly. */
4885 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
4886 /* Convert to the base in which the function was declared. */
4887 gcc_assert (cand->conversion_path != NULL_TREE);
4888 converted_arg = build_base_path (PLUS_EXPR,
4890 cand->conversion_path,
4892 /* Check that the base class is accessible. */
4893 if (!accessible_base_p (TREE_TYPE (argtype),
4894 BINFO_TYPE (cand->conversion_path), true))
4895 error ("%qT is not an accessible base of %qT",
4896 BINFO_TYPE (cand->conversion_path),
4897 TREE_TYPE (argtype));
4898 /* If fn was found by a using declaration, the conversion path
4899 will be to the derived class, not the base declaring fn. We
4900 must convert from derived to base. */
4901 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
4902 TREE_TYPE (parmtype), ba_unique, NULL);
4903 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
4906 argarray[j++] = converted_arg;
4907 parm = TREE_CHAIN (parm);
4908 arg = TREE_CHAIN (arg);
4914 parm = TREE_CHAIN (parm), arg = TREE_CHAIN (arg), ++i)
4916 tree type = TREE_VALUE (parm);
4920 /* Don't make a copy here if build_call is going to. */
4921 if (conv->kind == ck_rvalue
4922 && !TREE_ADDRESSABLE (complete_type (type)))
4923 conv = conv->u.next;
4925 val = convert_like_with_context
4926 (conv, TREE_VALUE (arg), fn, i - is_method);
4928 val = convert_for_arg_passing (type, val);
4929 argarray[j++] = val;
4932 /* Default arguments */
4933 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
4934 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
4935 TREE_PURPOSE (parm),
4938 for (; arg; arg = TREE_CHAIN (arg))
4940 tree a = TREE_VALUE (arg);
4941 if (magic_varargs_p (fn))
4942 /* Do no conversions for magic varargs. */;
4944 a = convert_arg_to_ellipsis (a);
4948 gcc_assert (j <= nargs);
4951 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
4952 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
4954 /* Avoid actually calling copy constructors and copy assignment operators,
4957 if (! flag_elide_constructors)
4958 /* Do things the hard way. */;
4959 else if (cand->num_convs == 1 && DECL_COPY_CONSTRUCTOR_P (fn))
4962 arg = argarray[num_artificial_parms_for (fn)];
4964 /* Pull out the real argument, disregarding const-correctness. */
4966 while (TREE_CODE (targ) == NOP_EXPR
4967 || TREE_CODE (targ) == NON_LVALUE_EXPR
4968 || TREE_CODE (targ) == CONVERT_EXPR)
4969 targ = TREE_OPERAND (targ, 0);
4970 if (TREE_CODE (targ) == ADDR_EXPR)
4972 targ = TREE_OPERAND (targ, 0);
4973 if (!same_type_ignoring_top_level_qualifiers_p
4974 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
4983 arg = build_indirect_ref (arg, 0);
4985 /* [class.copy]: the copy constructor is implicitly defined even if
4986 the implementation elided its use. */
4987 if (TYPE_HAS_COMPLEX_INIT_REF (DECL_CONTEXT (fn)))
4990 /* If we're creating a temp and we already have one, don't create a
4991 new one. If we're not creating a temp but we get one, use
4992 INIT_EXPR to collapse the temp into our target. Otherwise, if the
4993 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
4994 temp or an INIT_EXPR otherwise. */
4995 if (integer_zerop (TREE_VALUE (args)))
4997 if (TREE_CODE (arg) == TARGET_EXPR)
4999 else if (TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5000 return build_target_expr_with_type (arg, DECL_CONTEXT (fn));
5002 else if (TREE_CODE (arg) == TARGET_EXPR
5003 || TYPE_HAS_TRIVIAL_INIT_REF (DECL_CONTEXT (fn)))
5005 tree to = stabilize_reference
5006 (build_indirect_ref (TREE_VALUE (args), 0));
5008 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
5012 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
5014 && TYPE_HAS_TRIVIAL_ASSIGN_REF (DECL_CONTEXT (fn)))
5016 tree to = stabilize_reference
5017 (build_indirect_ref (argarray[0], 0));
5018 tree type = TREE_TYPE (to);
5019 tree as_base = CLASSTYPE_AS_BASE (type);
5022 if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
5024 arg = build_indirect_ref (arg, 0);
5025 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
5029 /* We must only copy the non-tail padding parts.
5030 Use __builtin_memcpy for the bitwise copy. */
5032 tree arg0, arg1, arg2, t;
5034 arg2 = TYPE_SIZE_UNIT (as_base);
5036 arg0 = build_unary_op (ADDR_EXPR, to, 0);
5037 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
5038 t = build_call_n (t, 3, arg0, arg1, arg2);
5040 t = convert (TREE_TYPE (arg0), t);
5041 val = build_indirect_ref (t, 0);
5049 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
5052 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
5055 gcc_assert (binfo && binfo != error_mark_node);
5057 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
5058 if (TREE_SIDE_EFFECTS (argarray[0]))
5059 argarray[0] = save_expr (argarray[0]);
5060 t = build_pointer_type (TREE_TYPE (fn));
5061 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
5062 fn = build_java_interface_fn_ref (fn, argarray[0]);
5064 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
5067 else if (DECL_INLINE (fn))
5068 fn = inline_conversion (fn);
5070 fn = build_addr_func (fn);
5072 return build_cxx_call (fn, nargs, argarray);
5075 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
5076 This function performs no overload resolution, conversion, or other
5077 high-level operations. */
5080 build_cxx_call (tree fn, int nargs, tree *argarray)
5084 fn = build_call_a (fn, nargs, argarray);
5086 /* If this call might throw an exception, note that fact. */
5087 fndecl = get_callee_fndecl (fn);
5088 if ((!fndecl || !TREE_NOTHROW (fndecl))
5089 && at_function_scope_p ()
5091 cp_function_chain->can_throw = 1;
5093 /* Some built-in function calls will be evaluated at compile-time in
5095 fn = fold_if_not_in_template (fn);
5097 if (VOID_TYPE_P (TREE_TYPE (fn)))
5100 fn = require_complete_type (fn);
5101 if (fn == error_mark_node)
5102 return error_mark_node;
5104 if (IS_AGGR_TYPE (TREE_TYPE (fn)))
5105 fn = build_cplus_new (TREE_TYPE (fn), fn);
5106 return convert_from_reference (fn);
5109 static GTY(()) tree java_iface_lookup_fn;
5111 /* Make an expression which yields the address of the Java interface
5112 method FN. This is achieved by generating a call to libjava's
5113 _Jv_LookupInterfaceMethodIdx(). */
5116 build_java_interface_fn_ref (tree fn, tree instance)
5118 tree lookup_fn, method, idx;
5119 tree klass_ref, iface, iface_ref;
5122 if (!java_iface_lookup_fn)
5124 tree endlink = build_void_list_node ();
5125 tree t = tree_cons (NULL_TREE, ptr_type_node,
5126 tree_cons (NULL_TREE, ptr_type_node,
5127 tree_cons (NULL_TREE, java_int_type_node,
5129 java_iface_lookup_fn
5130 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx",
5131 build_function_type (ptr_type_node, t),
5132 0, NOT_BUILT_IN, NULL, NULL_TREE);
5135 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
5136 This is the first entry in the vtable. */
5137 klass_ref = build_vtbl_ref (build_indirect_ref (instance, 0),
5140 /* Get the java.lang.Class pointer for the interface being called. */
5141 iface = DECL_CONTEXT (fn);
5142 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
5143 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
5144 || DECL_CONTEXT (iface_ref) != iface)
5146 error ("could not find class$ field in java interface type %qT",
5148 return error_mark_node;
5150 iface_ref = build_address (iface_ref);
5151 iface_ref = convert (build_pointer_type (iface), iface_ref);
5153 /* Determine the itable index of FN. */
5155 for (method = TYPE_METHODS (iface); method; method = TREE_CHAIN (method))
5157 if (!DECL_VIRTUAL_P (method))
5163 idx = build_int_cst (NULL_TREE, i);
5165 lookup_fn = build1 (ADDR_EXPR,
5166 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
5167 java_iface_lookup_fn);
5168 return build_call_nary (ptr_type_node, lookup_fn,
5169 3, klass_ref, iface_ref, idx);
5172 /* Returns the value to use for the in-charge parameter when making a
5173 call to a function with the indicated NAME.
5175 FIXME:Can't we find a neater way to do this mapping? */
5178 in_charge_arg_for_name (tree name)
5180 if (name == base_ctor_identifier
5181 || name == base_dtor_identifier)
5182 return integer_zero_node;
5183 else if (name == complete_ctor_identifier)
5184 return integer_one_node;
5185 else if (name == complete_dtor_identifier)
5186 return integer_two_node;
5187 else if (name == deleting_dtor_identifier)
5188 return integer_three_node;
5190 /* This function should only be called with one of the names listed
5196 /* Build a call to a constructor, destructor, or an assignment
5197 operator for INSTANCE, an expression with class type. NAME
5198 indicates the special member function to call; ARGS are the
5199 arguments. BINFO indicates the base of INSTANCE that is to be
5200 passed as the `this' parameter to the member function called.
5202 FLAGS are the LOOKUP_* flags to use when processing the call.
5204 If NAME indicates a complete object constructor, INSTANCE may be
5205 NULL_TREE. In this case, the caller will call build_cplus_new to
5206 store the newly constructed object into a VAR_DECL. */
5209 build_special_member_call (tree instance, tree name, tree args,
5210 tree binfo, int flags)
5213 /* The type of the subobject to be constructed or destroyed. */
5216 gcc_assert (name == complete_ctor_identifier
5217 || name == base_ctor_identifier
5218 || name == complete_dtor_identifier
5219 || name == base_dtor_identifier
5220 || name == deleting_dtor_identifier
5221 || name == ansi_assopname (NOP_EXPR));
5224 /* Resolve the name. */
5225 if (!complete_type_or_else (binfo, NULL_TREE))
5226 return error_mark_node;
5228 binfo = TYPE_BINFO (binfo);
5231 gcc_assert (binfo != NULL_TREE);
5233 class_type = BINFO_TYPE (binfo);
5235 /* Handle the special case where INSTANCE is NULL_TREE. */
5236 if (name == complete_ctor_identifier && !instance)
5238 instance = build_int_cst (build_pointer_type (class_type), 0);
5239 instance = build1 (INDIRECT_REF, class_type, instance);
5243 if (name == complete_dtor_identifier
5244 || name == base_dtor_identifier
5245 || name == deleting_dtor_identifier)
5246 gcc_assert (args == NULL_TREE);
5248 /* Convert to the base class, if necessary. */
5249 if (!same_type_ignoring_top_level_qualifiers_p
5250 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
5252 if (name != ansi_assopname (NOP_EXPR))
5253 /* For constructors and destructors, either the base is
5254 non-virtual, or it is virtual but we are doing the
5255 conversion from a constructor or destructor for the
5256 complete object. In either case, we can convert
5258 instance = convert_to_base_statically (instance, binfo);
5260 /* However, for assignment operators, we must convert
5261 dynamically if the base is virtual. */
5262 instance = build_base_path (PLUS_EXPR, instance,
5263 binfo, /*nonnull=*/1);
5267 gcc_assert (instance != NULL_TREE);
5269 fns = lookup_fnfields (binfo, name, 1);
5271 /* When making a call to a constructor or destructor for a subobject
5272 that uses virtual base classes, pass down a pointer to a VTT for
5274 if ((name == base_ctor_identifier
5275 || name == base_dtor_identifier)
5276 && CLASSTYPE_VBASECLASSES (class_type))
5281 /* If the current function is a complete object constructor
5282 or destructor, then we fetch the VTT directly.
5283 Otherwise, we look it up using the VTT we were given. */
5284 vtt = TREE_CHAIN (CLASSTYPE_VTABLES (current_class_type));
5285 vtt = decay_conversion (vtt);
5286 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
5287 build2 (EQ_EXPR, boolean_type_node,
5288 current_in_charge_parm, integer_zero_node),
5291 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
5292 sub_vtt = build2 (PLUS_EXPR, TREE_TYPE (vtt), vtt,
5293 BINFO_SUBVTT_INDEX (binfo));
5295 args = tree_cons (NULL_TREE, sub_vtt, args);
5298 return build_new_method_call (instance, fns, args,
5299 TYPE_BINFO (BINFO_TYPE (binfo)),
5300 flags, /*fn=*/NULL);
5303 /* Return the NAME, as a C string. The NAME indicates a function that
5304 is a member of TYPE. *FREE_P is set to true if the caller must
5305 free the memory returned.
5307 Rather than go through all of this, we should simply set the names
5308 of constructors and destructors appropriately, and dispense with
5309 ctor_identifier, dtor_identifier, etc. */
5312 name_as_c_string (tree name, tree type, bool *free_p)
5316 /* Assume that we will not allocate memory. */
5318 /* Constructors and destructors are special. */
5319 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5322 = (char *) IDENTIFIER_POINTER (constructor_name (type));
5323 /* For a destructor, add the '~'. */
5324 if (name == complete_dtor_identifier
5325 || name == base_dtor_identifier
5326 || name == deleting_dtor_identifier)
5328 pretty_name = concat ("~", pretty_name, NULL);
5329 /* Remember that we need to free the memory allocated. */
5333 else if (IDENTIFIER_TYPENAME_P (name))
5335 pretty_name = concat ("operator ",
5336 type_as_string (TREE_TYPE (name),
5337 TFF_PLAIN_IDENTIFIER),
5339 /* Remember that we need to free the memory allocated. */
5343 pretty_name = (char *) IDENTIFIER_POINTER (name);
5348 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
5349 be set, upon return, to the function called. */
5352 build_new_method_call (tree instance, tree fns, tree args,
5353 tree conversion_path, int flags,
5356 struct z_candidate *candidates = 0, *cand;
5357 tree explicit_targs = NULL_TREE;
5358 tree basetype = NULL_TREE;
5361 tree mem_args = NULL_TREE, instance_ptr;
5367 int template_only = 0;
5374 gcc_assert (instance != NULL_TREE);
5376 /* We don't know what function we're going to call, yet. */
5380 if (error_operand_p (instance)
5381 || error_operand_p (fns)
5382 || args == error_mark_node)
5383 return error_mark_node;
5385 if (!BASELINK_P (fns))
5387 error ("call to non-function %qD", fns);
5388 return error_mark_node;
5391 orig_instance = instance;
5395 /* Dismantle the baselink to collect all the information we need. */
5396 if (!conversion_path)
5397 conversion_path = BASELINK_BINFO (fns);
5398 access_binfo = BASELINK_ACCESS_BINFO (fns);
5399 optype = BASELINK_OPTYPE (fns);
5400 fns = BASELINK_FUNCTIONS (fns);
5401 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
5403 explicit_targs = TREE_OPERAND (fns, 1);
5404 fns = TREE_OPERAND (fns, 0);
5407 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
5408 || TREE_CODE (fns) == TEMPLATE_DECL
5409 || TREE_CODE (fns) == OVERLOAD);
5410 fn = get_first_fn (fns);
5411 name = DECL_NAME (fn);
5413 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
5414 gcc_assert (CLASS_TYPE_P (basetype));
5416 if (processing_template_decl)
5418 instance = build_non_dependent_expr (instance);
5419 args = build_non_dependent_args (orig_args);
5422 /* The USER_ARGS are the arguments we will display to users if an
5423 error occurs. The USER_ARGS should not include any
5424 compiler-generated arguments. The "this" pointer hasn't been
5425 added yet. However, we must remove the VTT pointer if this is a
5426 call to a base-class constructor or destructor. */
5428 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
5430 /* Callers should explicitly indicate whether they want to construct
5431 the complete object or just the part without virtual bases. */
5432 gcc_assert (name != ctor_identifier);
5433 /* Similarly for destructors. */
5434 gcc_assert (name != dtor_identifier);
5435 /* Remove the VTT pointer, if present. */
5436 if ((name == base_ctor_identifier || name == base_dtor_identifier)
5437 && CLASSTYPE_VBASECLASSES (basetype))
5438 user_args = TREE_CHAIN (user_args);
5441 /* Process the argument list. */
5442 args = resolve_args (args);
5443 if (args == error_mark_node)
5444 return error_mark_node;
5446 instance_ptr = build_this (instance);
5448 /* It's OK to call destructors on cv-qualified objects. Therefore,
5449 convert the INSTANCE_PTR to the unqualified type, if necessary. */
5450 if (DECL_DESTRUCTOR_P (fn))
5452 tree type = build_pointer_type (basetype);
5453 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
5454 instance_ptr = build_nop (type, instance_ptr);
5455 name = complete_dtor_identifier;
5458 class_type = (conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE);
5459 mem_args = tree_cons (NULL_TREE, instance_ptr, args);
5461 /* Get the high-water mark for the CONVERSION_OBSTACK. */
5462 p = conversion_obstack_alloc (0);
5464 for (fn = fns; fn; fn = OVL_NEXT (fn))
5466 tree t = OVL_CURRENT (fn);
5469 /* We can end up here for copy-init of same or base class. */
5470 if ((flags & LOOKUP_ONLYCONVERTING)
5471 && DECL_NONCONVERTING_P (t))
5474 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (t))
5475 this_arglist = mem_args;
5477 this_arglist = args;
5479 if (TREE_CODE (t) == TEMPLATE_DECL)
5480 /* A member template. */
5481 add_template_candidate (&candidates, t,
5484 this_arglist, optype,
5489 else if (! template_only)
5490 add_function_candidate (&candidates, t,
5498 candidates = splice_viable (candidates, pedantic, &any_viable_p);
5501 if (!COMPLETE_TYPE_P (basetype))
5502 cxx_incomplete_type_error (instance_ptr, basetype);
5508 pretty_name = name_as_c_string (name, basetype, &free_p);
5509 error ("no matching function for call to %<%T::%s(%A)%#V%>",
5510 basetype, pretty_name, user_args,
5511 TREE_TYPE (TREE_TYPE (instance_ptr)));
5515 print_z_candidates (candidates);
5516 call = error_mark_node;
5520 cand = tourney (candidates);
5526 pretty_name = name_as_c_string (name, basetype, &free_p);
5527 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
5529 print_z_candidates (candidates);
5532 call = error_mark_node;
5538 if (!(flags & LOOKUP_NONVIRTUAL)
5539 && DECL_PURE_VIRTUAL_P (fn)
5540 && instance == current_class_ref
5541 && (DECL_CONSTRUCTOR_P (current_function_decl)
5542 || DECL_DESTRUCTOR_P (current_function_decl)))
5543 /* This is not an error, it is runtime undefined
5545 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
5546 "abstract virtual %q#D called from constructor"
5547 : "abstract virtual %q#D called from destructor"),
5550 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
5551 && is_dummy_object (instance_ptr))
5553 error ("cannot call member function %qD without object",
5555 call = error_mark_node;
5559 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
5560 && resolves_to_fixed_type_p (instance, 0))
5561 flags |= LOOKUP_NONVIRTUAL;
5562 /* Now we know what function is being called. */
5565 /* Build the actual CALL_EXPR. */
5566 call = build_over_call (cand, flags);
5567 /* In an expression of the form `a->f()' where `f' turns
5568 out to be a static member function, `a' is
5569 none-the-less evaluated. */
5570 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
5571 && !is_dummy_object (instance_ptr)
5572 && TREE_SIDE_EFFECTS (instance_ptr))
5573 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
5574 instance_ptr, call);
5575 else if (call != error_mark_node
5576 && DECL_DESTRUCTOR_P (cand->fn)
5577 && !VOID_TYPE_P (TREE_TYPE (call)))
5578 /* An explicit call of the form "x->~X()" has type
5579 "void". However, on platforms where destructors
5580 return "this" (i.e., those where
5581 targetm.cxx.cdtor_returns_this is true), such calls
5582 will appear to have a return value of pointer type
5583 to the low-level call machinery. We do not want to
5584 change the low-level machinery, since we want to be
5585 able to optimize "delete f()" on such platforms as
5586 "operator delete(~X(f()))" (rather than generating
5587 "t = f(), ~X(t), operator delete (t)"). */
5588 call = build_nop (void_type_node, call);
5593 if (processing_template_decl && call != error_mark_node)
5594 call = (build_min_non_dep_call_list
5596 build_min_nt (COMPONENT_REF, orig_instance, orig_fns, NULL_TREE),
5599 /* Free all the conversions we allocated. */
5600 obstack_free (&conversion_obstack, p);
5605 /* Returns true iff standard conversion sequence ICS1 is a proper
5606 subsequence of ICS2. */
5609 is_subseq (conversion *ics1, conversion *ics2)
5611 /* We can assume that a conversion of the same code
5612 between the same types indicates a subsequence since we only get
5613 here if the types we are converting from are the same. */
5615 while (ics1->kind == ck_rvalue
5616 || ics1->kind == ck_lvalue)
5617 ics1 = ics1->u.next;
5621 while (ics2->kind == ck_rvalue
5622 || ics2->kind == ck_lvalue)
5623 ics2 = ics2->u.next;
5625 if (ics2->kind == ck_user
5626 || ics2->kind == ck_ambig
5627 || ics2->kind == ck_identity)
5628 /* At this point, ICS1 cannot be a proper subsequence of
5629 ICS2. We can get a USER_CONV when we are comparing the
5630 second standard conversion sequence of two user conversion
5634 ics2 = ics2->u.next;
5636 if (ics2->kind == ics1->kind
5637 && same_type_p (ics2->type, ics1->type)
5638 && same_type_p (ics2->u.next->type,
5639 ics1->u.next->type))
5644 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
5645 be any _TYPE nodes. */
5648 is_properly_derived_from (tree derived, tree base)
5650 if (!IS_AGGR_TYPE_CODE (TREE_CODE (derived))
5651 || !IS_AGGR_TYPE_CODE (TREE_CODE (base)))
5654 /* We only allow proper derivation here. The DERIVED_FROM_P macro
5655 considers every class derived from itself. */
5656 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
5657 && DERIVED_FROM_P (base, derived));
5660 /* We build the ICS for an implicit object parameter as a pointer
5661 conversion sequence. However, such a sequence should be compared
5662 as if it were a reference conversion sequence. If ICS is the
5663 implicit conversion sequence for an implicit object parameter,
5664 modify it accordingly. */
5667 maybe_handle_implicit_object (conversion **ics)
5671 /* [over.match.funcs]
5673 For non-static member functions, the type of the
5674 implicit object parameter is "reference to cv X"
5675 where X is the class of which the function is a
5676 member and cv is the cv-qualification on the member
5677 function declaration. */
5678 conversion *t = *ics;
5679 tree reference_type;
5681 /* The `this' parameter is a pointer to a class type. Make the
5682 implicit conversion talk about a reference to that same class
5684 reference_type = TREE_TYPE (t->type);
5685 reference_type = build_reference_type (reference_type);
5687 if (t->kind == ck_qual)
5689 if (t->kind == ck_ptr)
5691 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
5692 t = direct_reference_binding (reference_type, t);
5697 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
5698 and return the type to which the reference refers. Otherwise,
5699 leave *ICS unchanged and return NULL_TREE. */
5702 maybe_handle_ref_bind (conversion **ics)
5704 if ((*ics)->kind == ck_ref_bind)
5706 conversion *old_ics = *ics;
5707 tree type = TREE_TYPE (old_ics->type);
5708 *ics = old_ics->u.next;
5709 (*ics)->user_conv_p = old_ics->user_conv_p;
5710 (*ics)->bad_p = old_ics->bad_p;
5717 /* Compare two implicit conversion sequences according to the rules set out in
5718 [over.ics.rank]. Return values:
5720 1: ics1 is better than ics2
5721 -1: ics2 is better than ics1
5722 0: ics1 and ics2 are indistinguishable */
5725 compare_ics (conversion *ics1, conversion *ics2)
5731 tree deref_from_type1 = NULL_TREE;
5732 tree deref_from_type2 = NULL_TREE;
5733 tree deref_to_type1 = NULL_TREE;
5734 tree deref_to_type2 = NULL_TREE;
5735 conversion_rank rank1, rank2;
5737 /* REF_BINDING is nonzero if the result of the conversion sequence
5738 is a reference type. In that case TARGET_TYPE is the
5739 type referred to by the reference. */
5743 /* Handle implicit object parameters. */
5744 maybe_handle_implicit_object (&ics1);
5745 maybe_handle_implicit_object (&ics2);
5747 /* Handle reference parameters. */
5748 target_type1 = maybe_handle_ref_bind (&ics1);
5749 target_type2 = maybe_handle_ref_bind (&ics2);
5753 When comparing the basic forms of implicit conversion sequences (as
5754 defined in _over.best.ics_)
5756 --a standard conversion sequence (_over.ics.scs_) is a better
5757 conversion sequence than a user-defined conversion sequence
5758 or an ellipsis conversion sequence, and
5760 --a user-defined conversion sequence (_over.ics.user_) is a
5761 better conversion sequence than an ellipsis conversion sequence
5762 (_over.ics.ellipsis_). */
5763 rank1 = CONVERSION_RANK (ics1);
5764 rank2 = CONVERSION_RANK (ics2);
5768 else if (rank1 < rank2)
5771 if (rank1 == cr_bad)
5773 /* XXX Isn't this an extension? */
5774 /* Both ICS are bad. We try to make a decision based on what
5775 would have happened if they'd been good. */
5776 if (ics1->user_conv_p > ics2->user_conv_p
5777 || ics1->rank > ics2->rank)
5779 else if (ics1->user_conv_p < ics2->user_conv_p
5780 || ics1->rank < ics2->rank)
5783 /* We couldn't make up our minds; try to figure it out below. */
5786 if (ics1->ellipsis_p)
5787 /* Both conversions are ellipsis conversions. */
5790 /* User-defined conversion sequence U1 is a better conversion sequence
5791 than another user-defined conversion sequence U2 if they contain the
5792 same user-defined conversion operator or constructor and if the sec-
5793 ond standard conversion sequence of U1 is better than the second
5794 standard conversion sequence of U2. */
5796 if (ics1->user_conv_p)
5801 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
5802 if (t1->kind == ck_ambig)
5804 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
5805 if (t2->kind == ck_ambig)
5808 if (t1->cand->fn != t2->cand->fn)
5811 /* We can just fall through here, after setting up
5812 FROM_TYPE1 and FROM_TYPE2. */
5813 from_type1 = t1->type;
5814 from_type2 = t2->type;
5821 /* We're dealing with two standard conversion sequences.
5825 Standard conversion sequence S1 is a better conversion
5826 sequence than standard conversion sequence S2 if
5828 --S1 is a proper subsequence of S2 (comparing the conversion
5829 sequences in the canonical form defined by _over.ics.scs_,
5830 excluding any Lvalue Transformation; the identity
5831 conversion sequence is considered to be a subsequence of
5832 any non-identity conversion sequence */
5835 while (t1->kind != ck_identity)
5837 from_type1 = t1->type;
5840 while (t2->kind != ck_identity)
5842 from_type2 = t2->type;
5845 if (same_type_p (from_type1, from_type2))
5847 if (is_subseq (ics1, ics2))
5849 if (is_subseq (ics2, ics1))
5852 /* Otherwise, one sequence cannot be a subsequence of the other; they
5853 don't start with the same type. This can happen when comparing the
5854 second standard conversion sequence in two user-defined conversion
5861 --the rank of S1 is better than the rank of S2 (by the rules
5864 Standard conversion sequences are ordered by their ranks: an Exact
5865 Match is a better conversion than a Promotion, which is a better
5866 conversion than a Conversion.
5868 Two conversion sequences with the same rank are indistinguishable
5869 unless one of the following rules applies:
5871 --A conversion that is not a conversion of a pointer, or pointer
5872 to member, to bool is better than another conversion that is such
5875 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
5876 so that we do not have to check it explicitly. */
5877 if (ics1->rank < ics2->rank)
5879 else if (ics2->rank < ics1->rank)
5882 to_type1 = ics1->type;
5883 to_type2 = ics2->type;
5885 if (TYPE_PTR_P (from_type1)
5886 && TYPE_PTR_P (from_type2)
5887 && TYPE_PTR_P (to_type1)
5888 && TYPE_PTR_P (to_type2))
5890 deref_from_type1 = TREE_TYPE (from_type1);
5891 deref_from_type2 = TREE_TYPE (from_type2);
5892 deref_to_type1 = TREE_TYPE (to_type1);
5893 deref_to_type2 = TREE_TYPE (to_type2);
5895 /* The rules for pointers to members A::* are just like the rules
5896 for pointers A*, except opposite: if B is derived from A then
5897 A::* converts to B::*, not vice versa. For that reason, we
5898 switch the from_ and to_ variables here. */
5899 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
5900 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
5901 || (TYPE_PTRMEMFUNC_P (from_type1)
5902 && TYPE_PTRMEMFUNC_P (from_type2)
5903 && TYPE_PTRMEMFUNC_P (to_type1)
5904 && TYPE_PTRMEMFUNC_P (to_type2)))
5906 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
5907 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
5908 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
5909 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
5912 if (deref_from_type1 != NULL_TREE
5913 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type1))
5914 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_from_type2)))
5916 /* This was one of the pointer or pointer-like conversions.
5920 --If class B is derived directly or indirectly from class A,
5921 conversion of B* to A* is better than conversion of B* to
5922 void*, and conversion of A* to void* is better than
5923 conversion of B* to void*. */
5924 if (TREE_CODE (deref_to_type1) == VOID_TYPE
5925 && TREE_CODE (deref_to_type2) == VOID_TYPE)
5927 if (is_properly_derived_from (deref_from_type1,
5930 else if (is_properly_derived_from (deref_from_type2,
5934 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
5935 || TREE_CODE (deref_to_type2) == VOID_TYPE)
5937 if (same_type_p (deref_from_type1, deref_from_type2))
5939 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
5941 if (is_properly_derived_from (deref_from_type1,
5945 /* We know that DEREF_TO_TYPE1 is `void' here. */
5946 else if (is_properly_derived_from (deref_from_type1,
5951 else if (IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type1))
5952 && IS_AGGR_TYPE_CODE (TREE_CODE (deref_to_type2)))
5956 --If class B is derived directly or indirectly from class A
5957 and class C is derived directly or indirectly from B,
5959 --conversion of C* to B* is better than conversion of C* to
5962 --conversion of B* to A* is better than conversion of C* to
5964 if (same_type_p (deref_from_type1, deref_from_type2))
5966 if (is_properly_derived_from (deref_to_type1,
5969 else if (is_properly_derived_from (deref_to_type2,
5973 else if (same_type_p (deref_to_type1, deref_to_type2))
5975 if (is_properly_derived_from (deref_from_type2,
5978 else if (is_properly_derived_from (deref_from_type1,
5984 else if (CLASS_TYPE_P (non_reference (from_type1))
5985 && same_type_p (from_type1, from_type2))
5987 tree from = non_reference (from_type1);
5991 --binding of an expression of type C to a reference of type
5992 B& is better than binding an expression of type C to a
5993 reference of type A&
5995 --conversion of C to B is better than conversion of C to A, */
5996 if (is_properly_derived_from (from, to_type1)
5997 && is_properly_derived_from (from, to_type2))
5999 if (is_properly_derived_from (to_type1, to_type2))
6001 else if (is_properly_derived_from (to_type2, to_type1))
6005 else if (CLASS_TYPE_P (non_reference (to_type1))
6006 && same_type_p (to_type1, to_type2))
6008 tree to = non_reference (to_type1);
6012 --binding of an expression of type B to a reference of type
6013 A& is better than binding an expression of type C to a
6014 reference of type A&,
6016 --conversion of B to A is better than conversion of C to A */
6017 if (is_properly_derived_from (from_type1, to)
6018 && is_properly_derived_from (from_type2, to))
6020 if (is_properly_derived_from (from_type2, from_type1))
6022 else if (is_properly_derived_from (from_type1, from_type2))
6029 --S1 and S2 differ only in their qualification conversion and yield
6030 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
6031 qualification signature of type T1 is a proper subset of the cv-
6032 qualification signature of type T2 */
6033 if (ics1->kind == ck_qual
6034 && ics2->kind == ck_qual
6035 && same_type_p (from_type1, from_type2))
6036 return comp_cv_qual_signature (to_type1, to_type2);
6040 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
6041 types to which the references refer are the same type except for
6042 top-level cv-qualifiers, and the type to which the reference
6043 initialized by S2 refers is more cv-qualified than the type to
6044 which the reference initialized by S1 refers */
6046 if (target_type1 && target_type2
6047 && same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
6048 return comp_cv_qualification (target_type2, target_type1);
6050 /* Neither conversion sequence is better than the other. */
6054 /* The source type for this standard conversion sequence. */
6057 source_type (conversion *t)
6059 for (;; t = t->u.next)
6061 if (t->kind == ck_user
6062 || t->kind == ck_ambig
6063 || t->kind == ck_identity)
6069 /* Note a warning about preferring WINNER to LOSER. We do this by storing
6070 a pointer to LOSER and re-running joust to produce the warning if WINNER
6071 is actually used. */
6074 add_warning (struct z_candidate *winner, struct z_candidate *loser)
6076 candidate_warning *cw = (candidate_warning *)
6077 conversion_obstack_alloc (sizeof (candidate_warning));
6079 cw->next = winner->warnings;
6080 winner->warnings = cw;
6083 /* Compare two candidates for overloading as described in
6084 [over.match.best]. Return values:
6086 1: cand1 is better than cand2
6087 -1: cand2 is better than cand1
6088 0: cand1 and cand2 are indistinguishable */
6091 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
6094 int off1 = 0, off2 = 0;
6098 /* Candidates that involve bad conversions are always worse than those
6100 if (cand1->viable > cand2->viable)
6102 if (cand1->viable < cand2->viable)
6105 /* If we have two pseudo-candidates for conversions to the same type,
6106 or two candidates for the same function, arbitrarily pick one. */
6107 if (cand1->fn == cand2->fn
6108 && (IS_TYPE_OR_DECL_P (cand1->fn)))
6111 /* a viable function F1
6112 is defined to be a better function than another viable function F2 if
6113 for all arguments i, ICSi(F1) is not a worse conversion sequence than
6114 ICSi(F2), and then */
6116 /* for some argument j, ICSj(F1) is a better conversion sequence than
6119 /* For comparing static and non-static member functions, we ignore
6120 the implicit object parameter of the non-static function. The
6121 standard says to pretend that the static function has an object
6122 parm, but that won't work with operator overloading. */
6123 len = cand1->num_convs;
6124 if (len != cand2->num_convs)
6126 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
6127 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
6129 gcc_assert (static_1 != static_2);
6140 for (i = 0; i < len; ++i)
6142 conversion *t1 = cand1->convs[i + off1];
6143 conversion *t2 = cand2->convs[i + off2];
6144 int comp = compare_ics (t1, t2);
6149 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
6150 == cr_std + cr_promotion)
6151 && t1->kind == ck_std
6152 && t2->kind == ck_std
6153 && TREE_CODE (t1->type) == INTEGER_TYPE
6154 && TREE_CODE (t2->type) == INTEGER_TYPE
6155 && (TYPE_PRECISION (t1->type)
6156 == TYPE_PRECISION (t2->type))
6157 && (TYPE_UNSIGNED (t1->u.next->type)
6158 || (TREE_CODE (t1->u.next->type)
6161 tree type = t1->u.next->type;
6163 struct z_candidate *w, *l;
6165 type1 = t1->type, type2 = t2->type,
6166 w = cand1, l = cand2;
6168 type1 = t2->type, type2 = t1->type,
6169 w = cand2, l = cand1;
6173 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
6174 type, type1, type2);
6175 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
6181 if (winner && comp != winner)
6190 /* warn about confusing overload resolution for user-defined conversions,
6191 either between a constructor and a conversion op, or between two
6193 if (winner && warn_conversion && cand1->second_conv
6194 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
6195 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
6197 struct z_candidate *w, *l;
6198 bool give_warning = false;
6201 w = cand1, l = cand2;
6203 w = cand2, l = cand1;
6205 /* We don't want to complain about `X::operator T1 ()'
6206 beating `X::operator T2 () const', when T2 is a no less
6207 cv-qualified version of T1. */
6208 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
6209 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
6211 tree t = TREE_TYPE (TREE_TYPE (l->fn));
6212 tree f = TREE_TYPE (TREE_TYPE (w->fn));
6214 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
6219 if (!comp_ptr_ttypes (t, f))
6220 give_warning = true;
6223 give_warning = true;
6229 tree source = source_type (w->convs[0]);
6230 if (! DECL_CONSTRUCTOR_P (w->fn))
6231 source = TREE_TYPE (source);
6232 warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn);
6233 warning (OPT_Wconversion, " for conversion from %qT to %qT",
6234 source, w->second_conv->type);
6235 inform (" because conversion sequence for the argument is better");
6245 F1 is a non-template function and F2 is a template function
6248 if (!cand1->template_decl && cand2->template_decl)
6250 else if (cand1->template_decl && !cand2->template_decl)
6254 F1 and F2 are template functions and the function template for F1 is
6255 more specialized than the template for F2 according to the partial
6258 if (cand1->template_decl && cand2->template_decl)
6260 winner = more_specialized_fn
6261 (TI_TEMPLATE (cand1->template_decl),
6262 TI_TEMPLATE (cand2->template_decl),
6263 /* [temp.func.order]: The presence of unused ellipsis and default
6264 arguments has no effect on the partial ordering of function
6265 templates. add_function_candidate() will not have
6266 counted the "this" argument for constructors. */
6267 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
6273 the context is an initialization by user-defined conversion (see
6274 _dcl.init_ and _over.match.user_) and the standard conversion
6275 sequence from the return type of F1 to the destination type (i.e.,
6276 the type of the entity being initialized) is a better conversion
6277 sequence than the standard conversion sequence from the return type
6278 of F2 to the destination type. */
6280 if (cand1->second_conv)
6282 winner = compare_ics (cand1->second_conv, cand2->second_conv);
6287 /* Check whether we can discard a builtin candidate, either because we
6288 have two identical ones or matching builtin and non-builtin candidates.
6290 (Pedantically in the latter case the builtin which matched the user
6291 function should not be added to the overload set, but we spot it here.
6294 ... the builtin candidates include ...
6295 - do not have the same parameter type list as any non-template
6296 non-member candidate. */
6298 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
6299 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
6301 for (i = 0; i < len; ++i)
6302 if (!same_type_p (cand1->convs[i]->type,
6303 cand2->convs[i]->type))
6305 if (i == cand1->num_convs)
6307 if (cand1->fn == cand2->fn)
6308 /* Two built-in candidates; arbitrarily pick one. */
6310 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
6311 /* cand1 is built-in; prefer cand2. */
6314 /* cand2 is built-in; prefer cand1. */
6319 /* If the two functions are the same (this can happen with declarations
6320 in multiple scopes and arg-dependent lookup), arbitrarily choose one. */
6321 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
6322 && equal_functions (cand1->fn, cand2->fn))
6327 /* Extension: If the worst conversion for one candidate is worse than the
6328 worst conversion for the other, take the first. */
6331 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
6332 struct z_candidate *w = 0, *l = 0;
6334 for (i = 0; i < len; ++i)
6336 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
6337 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
6338 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
6339 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
6342 winner = 1, w = cand1, l = cand2;
6344 winner = -1, w = cand2, l = cand1;
6350 ISO C++ says that these are ambiguous, even \
6351 though the worst conversion for the first is better than \
6352 the worst conversion for the second:");
6353 print_z_candidate (_("candidate 1:"), w);
6354 print_z_candidate (_("candidate 2:"), l);
6362 gcc_assert (!winner);
6366 /* Given a list of candidates for overloading, find the best one, if any.
6367 This algorithm has a worst case of O(2n) (winner is last), and a best
6368 case of O(n/2) (totally ambiguous); much better than a sorting
6371 static struct z_candidate *
6372 tourney (struct z_candidate *candidates)
6374 struct z_candidate *champ = candidates, *challenger;
6376 int champ_compared_to_predecessor = 0;
6378 /* Walk through the list once, comparing each current champ to the next
6379 candidate, knocking out a candidate or two with each comparison. */
6381 for (challenger = champ->next; challenger; )
6383 fate = joust (champ, challenger, 0);
6385 challenger = challenger->next;
6390 champ = challenger->next;
6393 champ_compared_to_predecessor = 0;
6398 champ_compared_to_predecessor = 1;
6401 challenger = champ->next;
6405 /* Make sure the champ is better than all the candidates it hasn't yet
6406 been compared to. */
6408 for (challenger = candidates;
6410 && !(champ_compared_to_predecessor && challenger->next == champ);
6411 challenger = challenger->next)
6413 fate = joust (champ, challenger, 0);
6421 /* Returns nonzero if things of type FROM can be converted to TO. */
6424 can_convert (tree to, tree from)
6426 return can_convert_arg (to, from, NULL_TREE, LOOKUP_NORMAL);
6429 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
6432 can_convert_arg (tree to, tree from, tree arg, int flags)
6438 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6439 p = conversion_obstack_alloc (0);
6441 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6443 ok_p = (t && !t->bad_p);
6445 /* Free all the conversions we allocated. */
6446 obstack_free (&conversion_obstack, p);
6451 /* Like can_convert_arg, but allows dubious conversions as well. */
6454 can_convert_arg_bad (tree to, tree from, tree arg)
6459 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6460 p = conversion_obstack_alloc (0);
6461 /* Try to perform the conversion. */
6462 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
6464 /* Free all the conversions we allocated. */
6465 obstack_free (&conversion_obstack, p);
6470 /* Convert EXPR to TYPE. Return the converted expression.
6472 Note that we allow bad conversions here because by the time we get to
6473 this point we are committed to doing the conversion. If we end up
6474 doing a bad conversion, convert_like will complain. */
6477 perform_implicit_conversion (tree type, tree expr)
6482 if (error_operand_p (expr))
6483 return error_mark_node;
6485 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6486 p = conversion_obstack_alloc (0);
6488 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6493 error ("could not convert %qE to %qT", expr, type);
6494 expr = error_mark_node;
6496 else if (processing_template_decl)
6498 /* In a template, we are only concerned about determining the
6499 type of non-dependent expressions, so we do not have to
6500 perform the actual conversion. */
6501 if (TREE_TYPE (expr) != type)
6502 expr = build_nop (type, expr);
6505 expr = convert_like (conv, expr);
6507 /* Free all the conversions we allocated. */
6508 obstack_free (&conversion_obstack, p);
6513 /* Convert EXPR to TYPE (as a direct-initialization) if that is
6514 permitted. If the conversion is valid, the converted expression is
6515 returned. Otherwise, NULL_TREE is returned, except in the case
6516 that TYPE is a class type; in that case, an error is issued. If
6517 C_CAST_P is true, then this direction initialization is taking
6518 place as part of a static_cast being attempted as part of a C-style
6522 perform_direct_initialization_if_possible (tree type,
6529 if (type == error_mark_node || error_operand_p (expr))
6530 return error_mark_node;
6533 If the destination type is a (possibly cv-qualified) class type:
6535 -- If the initialization is direct-initialization ...,
6536 constructors are considered. ... If no constructor applies, or
6537 the overload resolution is ambiguous, the initialization is
6539 if (CLASS_TYPE_P (type))
6541 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
6542 build_tree_list (NULL_TREE, expr),
6543 type, LOOKUP_NORMAL);
6544 return build_cplus_new (type, expr);
6547 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6548 p = conversion_obstack_alloc (0);
6550 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
6553 if (!conv || conv->bad_p)
6556 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
6557 /*issue_conversion_warnings=*/false,
6560 /* Free all the conversions we allocated. */
6561 obstack_free (&conversion_obstack, p);
6566 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
6567 is being bound to a temporary. Create and return a new VAR_DECL
6568 with the indicated TYPE; this variable will store the value to
6569 which the reference is bound. */
6572 make_temporary_var_for_ref_to_temp (tree decl, tree type)
6576 /* Create the variable. */
6577 var = create_temporary_var (type);
6579 /* Register the variable. */
6580 if (TREE_STATIC (decl))
6582 /* Namespace-scope or local static; give it a mangled name. */
6585 TREE_STATIC (var) = 1;
6586 name = mangle_ref_init_variable (decl);
6587 DECL_NAME (var) = name;
6588 SET_DECL_ASSEMBLER_NAME (var, name);
6589 var = pushdecl_top_level (var);
6592 /* Create a new cleanup level if necessary. */
6593 maybe_push_cleanup_level (type);
6598 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
6599 initializing a variable of that TYPE. If DECL is non-NULL, it is
6600 the VAR_DECL being initialized with the EXPR. (In that case, the
6601 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
6602 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
6603 return, if *CLEANUP is no longer NULL, it will be an expression
6604 that should be pushed as a cleanup after the returned expression
6605 is used to initialize DECL.
6607 Return the converted expression. */
6610 initialize_reference (tree type, tree expr, tree decl, tree *cleanup)
6615 if (type == error_mark_node || error_operand_p (expr))
6616 return error_mark_node;
6618 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6619 p = conversion_obstack_alloc (0);
6621 conv = reference_binding (type, TREE_TYPE (expr), expr, LOOKUP_NORMAL);
6622 if (!conv || conv->bad_p)
6624 if (!(TYPE_QUALS (TREE_TYPE (type)) & TYPE_QUAL_CONST)
6625 && !real_lvalue_p (expr))
6626 error ("invalid initialization of non-const reference of "
6627 "type %qT from a temporary of type %qT",
6628 type, TREE_TYPE (expr));
6630 error ("invalid initialization of reference of type "
6631 "%qT from expression of type %qT", type,
6633 return error_mark_node;
6636 /* If DECL is non-NULL, then this special rule applies:
6640 The temporary to which the reference is bound or the temporary
6641 that is the complete object to which the reference is bound
6642 persists for the lifetime of the reference.
6644 The temporaries created during the evaluation of the expression
6645 initializing the reference, except the temporary to which the
6646 reference is bound, are destroyed at the end of the
6647 full-expression in which they are created.
6649 In that case, we store the converted expression into a new
6650 VAR_DECL in a new scope.
6652 However, we want to be careful not to create temporaries when
6653 they are not required. For example, given:
6656 struct D : public B {};
6660 there is no need to copy the return value from "f"; we can just
6661 extend its lifetime. Similarly, given:
6664 struct T { operator S(); };
6668 we can extend the lifetime of the return value of the conversion
6670 gcc_assert (conv->kind == ck_ref_bind);
6674 tree base_conv_type;
6676 /* Skip over the REF_BIND. */
6677 conv = conv->u.next;
6678 /* If the next conversion is a BASE_CONV, skip that too -- but
6679 remember that the conversion was required. */
6680 if (conv->kind == ck_base)
6682 if (conv->check_copy_constructor_p)
6683 check_constructor_callable (TREE_TYPE (expr), expr);
6684 base_conv_type = conv->type;
6685 conv = conv->u.next;
6688 base_conv_type = NULL_TREE;
6689 /* Perform the remainder of the conversion. */
6690 expr = convert_like_real (conv, expr,
6691 /*fn=*/NULL_TREE, /*argnum=*/0,
6693 /*issue_conversion_warnings=*/true,
6694 /*c_cast_p=*/false);
6695 if (error_operand_p (expr))
6696 expr = error_mark_node;
6699 if (!real_lvalue_p (expr))
6704 /* Create the temporary variable. */
6705 type = TREE_TYPE (expr);
6706 var = make_temporary_var_for_ref_to_temp (decl, type);
6707 layout_decl (var, 0);
6708 /* If the rvalue is the result of a function call it will be
6709 a TARGET_EXPR. If it is some other construct (such as a
6710 member access expression where the underlying object is
6711 itself the result of a function call), turn it into a
6712 TARGET_EXPR here. It is important that EXPR be a
6713 TARGET_EXPR below since otherwise the INIT_EXPR will
6714 attempt to make a bitwise copy of EXPR to initialize
6716 if (TREE_CODE (expr) != TARGET_EXPR)
6717 expr = get_target_expr (expr);
6718 /* Create the INIT_EXPR that will initialize the temporary
6720 init = build2 (INIT_EXPR, type, var, expr);
6721 if (at_function_scope_p ())
6723 add_decl_expr (var);
6724 *cleanup = cxx_maybe_build_cleanup (var);
6726 /* We must be careful to destroy the temporary only
6727 after its initialization has taken place. If the
6728 initialization throws an exception, then the
6729 destructor should not be run. We cannot simply
6730 transform INIT into something like:
6732 (INIT, ({ CLEANUP_STMT; }))
6734 because emit_local_var always treats the
6735 initializer as a full-expression. Thus, the
6736 destructor would run too early; it would run at the
6737 end of initializing the reference variable, rather
6738 than at the end of the block enclosing the
6741 The solution is to pass back a cleanup expression
6742 which the caller is responsible for attaching to
6743 the statement tree. */
6747 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
6748 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
6749 static_aggregates = tree_cons (NULL_TREE, var,
6752 /* Use its address to initialize the reference variable. */
6753 expr = build_address (var);
6755 expr = convert_to_base (expr,
6756 build_pointer_type (base_conv_type),
6757 /*check_access=*/true,
6759 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
6762 /* Take the address of EXPR. */
6763 expr = build_unary_op (ADDR_EXPR, expr, 0);
6764 /* If a BASE_CONV was required, perform it now. */
6766 expr = (perform_implicit_conversion
6767 (build_pointer_type (base_conv_type), expr));
6768 expr = build_nop (type, expr);
6772 /* Perform the conversion. */
6773 expr = convert_like (conv, expr);
6775 /* Free all the conversions we allocated. */
6776 obstack_free (&conversion_obstack, p);
6781 #include "gt-cp-call.h"