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, 2008, 2009, 2010
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 3, 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 COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
29 #include "coretypes.h"
36 #include "diagnostic-core.h"
40 #include "langhooks.h"
41 #include "c-family/c-objc.h"
43 /* The various kinds of conversion. */
45 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 /* True if this conversion would be permitted with a bending of
89 language standards, e.g. disregarding pointer qualifiers or
90 converting integers to pointers. */
91 BOOL_BITFIELD bad_p : 1;
92 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
93 temporary should be created to hold the result of the
95 BOOL_BITFIELD need_temporary_p : 1;
96 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
97 from a pointer-to-derived to pointer-to-base is being performed. */
98 BOOL_BITFIELD base_p : 1;
99 /* If KIND is ck_ref_bind, true when either an lvalue reference is
100 being bound to an lvalue expression or an rvalue reference is
101 being bound to an rvalue expression. If KIND is ck_rvalue,
102 true when we should treat an lvalue as an rvalue (12.8p33). If
103 KIND is ck_base, always false. */
104 BOOL_BITFIELD rvaluedness_matches_p: 1;
105 BOOL_BITFIELD check_narrowing: 1;
106 /* The type of the expression resulting from the conversion. */
109 /* The next conversion in the chain. Since the conversions are
110 arranged from outermost to innermost, the NEXT conversion will
111 actually be performed before this conversion. This variant is
112 used only when KIND is neither ck_identity nor ck_ambig. */
114 /* The expression at the beginning of the conversion chain. This
115 variant is used only if KIND is ck_identity or ck_ambig. */
117 /* The array of conversions for an initializer_list. */
120 /* The function candidate corresponding to this conversion
121 sequence. This field is only used if KIND is ck_user. */
122 struct z_candidate *cand;
125 #define CONVERSION_RANK(NODE) \
126 ((NODE)->bad_p ? cr_bad \
127 : (NODE)->ellipsis_p ? cr_ellipsis \
128 : (NODE)->user_conv_p ? cr_user \
131 #define BAD_CONVERSION_RANK(NODE) \
132 ((NODE)->ellipsis_p ? cr_ellipsis \
133 : (NODE)->user_conv_p ? cr_user \
136 static struct obstack conversion_obstack;
137 static bool conversion_obstack_initialized;
138 struct rejection_reason;
140 static struct z_candidate * tourney (struct z_candidate *);
141 static int equal_functions (tree, tree);
142 static int joust (struct z_candidate *, struct z_candidate *, bool);
143 static int compare_ics (conversion *, conversion *);
144 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
145 static tree build_java_interface_fn_ref (tree, tree);
146 #define convert_like(CONV, EXPR, COMPLAIN) \
147 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
148 /*issue_conversion_warnings=*/true, \
149 /*c_cast_p=*/false, (COMPLAIN))
150 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
151 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
152 /*issue_conversion_warnings=*/true, \
153 /*c_cast_p=*/false, (COMPLAIN))
154 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
155 bool, tsubst_flags_t);
156 static void op_error (enum tree_code, enum tree_code, tree, tree,
158 static VEC(tree,gc) *resolve_args (VEC(tree,gc) *);
159 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
160 static void print_z_candidate (const char *, struct z_candidate *);
161 static void print_z_candidates (location_t, struct z_candidate *);
162 static tree build_this (tree);
163 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
164 static bool any_strictly_viable (struct z_candidate *);
165 static struct z_candidate *add_template_candidate
166 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
167 tree, tree, tree, int, unification_kind_t);
168 static struct z_candidate *add_template_candidate_real
169 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
170 tree, tree, tree, int, tree, unification_kind_t);
171 static struct z_candidate *add_template_conv_candidate
172 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
174 static void add_builtin_candidates
175 (struct z_candidate **, enum tree_code, enum tree_code,
177 static void add_builtin_candidate
178 (struct z_candidate **, enum tree_code, enum tree_code,
179 tree, tree, tree, tree *, tree *, int);
180 static bool is_complete (tree);
181 static void build_builtin_candidate
182 (struct z_candidate **, tree, tree, tree, tree *, tree *,
184 static struct z_candidate *add_conv_candidate
185 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
187 static struct z_candidate *add_function_candidate
188 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
190 static conversion *implicit_conversion (tree, tree, tree, bool, int);
191 static conversion *standard_conversion (tree, tree, tree, bool, int);
192 static conversion *reference_binding (tree, tree, tree, bool, int);
193 static conversion *build_conv (conversion_kind, tree, conversion *);
194 static conversion *build_list_conv (tree, tree, int);
195 static bool is_subseq (conversion *, conversion *);
196 static conversion *maybe_handle_ref_bind (conversion **);
197 static void maybe_handle_implicit_object (conversion **);
198 static struct z_candidate *add_candidate
199 (struct z_candidate **, tree, tree, const VEC(tree,gc) *, size_t,
200 conversion **, tree, tree, int, struct rejection_reason *);
201 static tree source_type (conversion *);
202 static void add_warning (struct z_candidate *, struct z_candidate *);
203 static bool reference_compatible_p (tree, tree);
204 static conversion *convert_class_to_reference (tree, tree, tree, int);
205 static conversion *direct_reference_binding (tree, conversion *);
206 static bool promoted_arithmetic_type_p (tree);
207 static conversion *conditional_conversion (tree, tree);
208 static char *name_as_c_string (tree, tree, bool *);
209 static tree prep_operand (tree);
210 static void add_candidates (tree, tree, const VEC(tree,gc) *, tree, tree, bool,
211 tree, tree, int, struct z_candidate **);
212 static conversion *merge_conversion_sequences (conversion *, conversion *);
213 static bool magic_varargs_p (tree);
214 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
216 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
217 NAME can take many forms... */
220 check_dtor_name (tree basetype, tree name)
222 /* Just accept something we've already complained about. */
223 if (name == error_mark_node)
226 if (TREE_CODE (name) == TYPE_DECL)
227 name = TREE_TYPE (name);
228 else if (TYPE_P (name))
230 else if (TREE_CODE (name) == IDENTIFIER_NODE)
232 if ((MAYBE_CLASS_TYPE_P (basetype)
233 && name == constructor_name (basetype))
234 || (TREE_CODE (basetype) == ENUMERAL_TYPE
235 && name == TYPE_IDENTIFIER (basetype)))
238 name = get_type_value (name);
244 template <class T> struct S { ~S(); };
248 NAME will be a class template. */
249 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
253 if (!name || name == error_mark_node)
255 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
258 /* We want the address of a function or method. We avoid creating a
259 pointer-to-member function. */
262 build_addr_func (tree function)
264 tree type = TREE_TYPE (function);
266 /* We have to do these by hand to avoid real pointer to member
268 if (TREE_CODE (type) == METHOD_TYPE)
270 if (TREE_CODE (function) == OFFSET_REF)
272 tree object = build_address (TREE_OPERAND (function, 0));
273 return get_member_function_from_ptrfunc (&object,
274 TREE_OPERAND (function, 1));
276 function = build_address (function);
279 function = decay_conversion (function);
284 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
285 POINTER_TYPE to those. Note, pointer to member function types
286 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
287 two variants. build_call_a is the primitive taking an array of
288 arguments, while build_call_n is a wrapper that handles varargs. */
291 build_call_n (tree function, int n, ...)
294 return build_call_a (function, 0, NULL);
297 tree *argarray = XALLOCAVEC (tree, n);
302 for (i = 0; i < n; i++)
303 argarray[i] = va_arg (ap, tree);
305 return build_call_a (function, n, argarray);
310 build_call_a (tree function, int n, tree *argarray)
312 int is_constructor = 0;
319 function = build_addr_func (function);
321 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
322 fntype = TREE_TYPE (TREE_TYPE (function));
323 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
324 || TREE_CODE (fntype) == METHOD_TYPE);
325 result_type = TREE_TYPE (fntype);
326 /* An rvalue has no cv-qualifiers. */
327 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
328 result_type = cv_unqualified (result_type);
330 if (TREE_CODE (function) == ADDR_EXPR
331 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
333 decl = TREE_OPERAND (function, 0);
334 if (!TREE_USED (decl))
336 /* We invoke build_call directly for several library
337 functions. These may have been declared normally if
338 we're building libgcc, so we can't just check
340 gcc_assert (DECL_ARTIFICIAL (decl)
341 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
349 /* We check both the decl and the type; a function may be known not to
350 throw without being declared throw(). */
351 nothrow = ((decl && TREE_NOTHROW (decl))
352 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
354 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
355 current_function_returns_abnormally = 1;
357 if (decl && TREE_DEPRECATED (decl))
358 warn_deprecated_use (decl, NULL_TREE);
359 require_complete_eh_spec_types (fntype, decl);
361 if (decl && DECL_CONSTRUCTOR_P (decl))
364 /* Don't pass empty class objects by value. This is useful
365 for tags in STL, which are used to control overload resolution.
366 We don't need to handle other cases of copying empty classes. */
367 if (! decl || ! DECL_BUILT_IN (decl))
368 for (i = 0; i < n; i++)
369 if (is_empty_class (TREE_TYPE (argarray[i]))
370 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
372 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
373 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
377 function = build_call_array_loc (input_location,
378 result_type, function, n, argarray);
379 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
380 TREE_NOTHROW (function) = nothrow;
385 /* Build something of the form ptr->method (args)
386 or object.method (args). This can also build
387 calls to constructors, and find friends.
389 Member functions always take their class variable
392 INSTANCE is a class instance.
394 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
396 PARMS help to figure out what that NAME really refers to.
398 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
399 down to the real instance type to use for access checking. We need this
400 information to get protected accesses correct.
402 FLAGS is the logical disjunction of zero or more LOOKUP_
403 flags. See cp-tree.h for more info.
405 If this is all OK, calls build_function_call with the resolved
408 This function must also handle being called to perform
409 initialization, promotion/coercion of arguments, and
410 instantiation of default parameters.
412 Note that NAME may refer to an instance variable name. If
413 `operator()()' is defined for the type of that field, then we return
416 /* New overloading code. */
418 typedef struct z_candidate z_candidate;
420 typedef struct candidate_warning candidate_warning;
421 struct candidate_warning {
423 candidate_warning *next;
426 /* Information for providing diagnostics about why overloading failed. */
428 enum rejection_reason_code {
432 rr_bad_arg_conversion
435 struct conversion_info {
436 /* The index of the argument, 0-based. */
438 /* The type of the actual argument. */
440 /* The type of the formal argument. */
444 struct rejection_reason {
445 enum rejection_reason_code code;
447 /* Information about an arity mismatch. */
449 /* The expected number of arguments. */
451 /* The actual number of arguments in the call. */
453 /* Whether the call was a varargs call. */
456 /* Information about an argument conversion mismatch. */
457 struct conversion_info conversion;
458 /* Same, but for bad argument conversions. */
459 struct conversion_info bad_conversion;
464 /* The FUNCTION_DECL that will be called if this candidate is
465 selected by overload resolution. */
467 /* If not NULL_TREE, the first argument to use when calling this
470 /* The rest of the arguments to use when calling this function. If
471 there are no further arguments this may be NULL or it may be an
473 const VEC(tree,gc) *args;
474 /* The implicit conversion sequences for each of the arguments to
477 /* The number of implicit conversion sequences. */
479 /* If FN is a user-defined conversion, the standard conversion
480 sequence from the type returned by FN to the desired destination
482 conversion *second_conv;
484 struct rejection_reason *reason;
485 /* If FN is a member function, the binfo indicating the path used to
486 qualify the name of FN at the call site. This path is used to
487 determine whether or not FN is accessible if it is selected by
488 overload resolution. The DECL_CONTEXT of FN will always be a
489 (possibly improper) base of this binfo. */
491 /* If FN is a non-static member function, the binfo indicating the
492 subobject to which the `this' pointer should be converted if FN
493 is selected by overload resolution. The type pointed to the by
494 the `this' pointer must correspond to the most derived class
495 indicated by the CONVERSION_PATH. */
496 tree conversion_path;
499 candidate_warning *warnings;
503 /* Returns true iff T is a null pointer constant in the sense of
507 null_ptr_cst_p (tree t)
511 A null pointer constant is an integral constant expression
512 (_expr.const_) rvalue of integer type that evaluates to zero or
513 an rvalue of type std::nullptr_t. */
514 if (NULLPTR_TYPE_P (TREE_TYPE (t)))
516 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)))
518 if (cxx_dialect >= cxx0x)
520 t = fold_non_dependent_expr (t);
521 t = maybe_constant_value (t);
522 if (TREE_CONSTANT (t) && integer_zerop (t))
527 t = integral_constant_value (t);
529 if (integer_zerop (t) && !TREE_OVERFLOW (t))
536 /* Returns nonzero if PARMLIST consists of only default parms and/or
540 sufficient_parms_p (const_tree parmlist)
542 for (; parmlist && parmlist != void_list_node;
543 parmlist = TREE_CHAIN (parmlist))
544 if (!TREE_PURPOSE (parmlist))
549 /* Allocate N bytes of memory from the conversion obstack. The memory
550 is zeroed before being returned. */
553 conversion_obstack_alloc (size_t n)
556 if (!conversion_obstack_initialized)
558 gcc_obstack_init (&conversion_obstack);
559 conversion_obstack_initialized = true;
561 p = obstack_alloc (&conversion_obstack, n);
566 /* Allocate rejection reasons. */
568 static struct rejection_reason *
569 alloc_rejection (enum rejection_reason_code code)
571 struct rejection_reason *p;
572 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
577 static struct rejection_reason *
578 arity_rejection (tree first_arg, int expected, int actual)
580 struct rejection_reason *r = alloc_rejection (rr_arity);
581 int adjust = first_arg != NULL_TREE;
582 r->u.arity.expected = expected - adjust;
583 r->u.arity.actual = actual - adjust;
587 static struct rejection_reason *
588 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
590 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
591 int adjust = first_arg != NULL_TREE;
592 r->u.conversion.n_arg = n_arg - adjust;
593 r->u.conversion.from_type = from;
594 r->u.conversion.to_type = to;
598 static struct rejection_reason *
599 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
601 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
602 int adjust = first_arg != NULL_TREE;
603 r->u.bad_conversion.n_arg = n_arg - adjust;
604 r->u.bad_conversion.from_type = from;
605 r->u.bad_conversion.to_type = to;
609 /* Dynamically allocate a conversion. */
612 alloc_conversion (conversion_kind kind)
615 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
620 #ifdef ENABLE_CHECKING
622 /* Make sure that all memory on the conversion obstack has been
626 validate_conversion_obstack (void)
628 if (conversion_obstack_initialized)
629 gcc_assert ((obstack_next_free (&conversion_obstack)
630 == obstack_base (&conversion_obstack)));
633 #endif /* ENABLE_CHECKING */
635 /* Dynamically allocate an array of N conversions. */
638 alloc_conversions (size_t n)
640 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
644 build_conv (conversion_kind code, tree type, conversion *from)
647 conversion_rank rank = CONVERSION_RANK (from);
649 /* Note that the caller is responsible for filling in t->cand for
650 user-defined conversions. */
651 t = alloc_conversion (code);
674 t->user_conv_p = (code == ck_user || from->user_conv_p);
675 t->bad_p = from->bad_p;
680 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
681 specialization of std::initializer_list<T>, if such a conversion is
685 build_list_conv (tree type, tree ctor, int flags)
687 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
688 unsigned len = CONSTRUCTOR_NELTS (ctor);
689 conversion **subconvs = alloc_conversions (len);
694 /* Within a list-initialization we can have more user-defined
696 flags &= ~LOOKUP_NO_CONVERSION;
697 /* But no narrowing conversions. */
698 flags |= LOOKUP_NO_NARROWING;
700 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
703 = implicit_conversion (elttype, TREE_TYPE (val), val,
711 t = alloc_conversion (ck_list);
713 t->u.list = subconvs;
716 for (i = 0; i < len; ++i)
718 conversion *sub = subconvs[i];
719 if (sub->rank > t->rank)
721 if (sub->user_conv_p)
722 t->user_conv_p = true;
730 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
731 is a valid aggregate initializer for array type ATYPE. */
734 can_convert_array (tree atype, tree ctor, int flags)
737 tree elttype = TREE_TYPE (atype);
738 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
740 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
742 if (TREE_CODE (elttype) == ARRAY_TYPE
743 && TREE_CODE (val) == CONSTRUCTOR)
744 ok = can_convert_array (elttype, val, flags);
746 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags);
753 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
754 aggregate class, if such a conversion is possible. */
757 build_aggr_conv (tree type, tree ctor, int flags)
759 unsigned HOST_WIDE_INT i = 0;
761 tree field = next_initializable_field (TYPE_FIELDS (type));
762 tree empty_ctor = NULL_TREE;
764 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
766 tree ftype = TREE_TYPE (field);
770 if (i < CONSTRUCTOR_NELTS (ctor))
771 val = CONSTRUCTOR_ELT (ctor, i)->value;
774 if (empty_ctor == NULL_TREE)
775 empty_ctor = build_constructor (init_list_type_node, NULL);
780 if (TREE_CODE (ftype) == ARRAY_TYPE
781 && TREE_CODE (val) == CONSTRUCTOR)
782 ok = can_convert_array (ftype, val, flags);
784 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags);
789 if (TREE_CODE (type) == UNION_TYPE)
793 if (i < CONSTRUCTOR_NELTS (ctor))
796 c = alloc_conversion (ck_aggr);
799 c->user_conv_p = true;
804 /* Build a representation of the identity conversion from EXPR to
805 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
808 build_identity_conv (tree type, tree expr)
812 c = alloc_conversion (ck_identity);
819 /* Converting from EXPR to TYPE was ambiguous in the sense that there
820 were multiple user-defined conversions to accomplish the job.
821 Build a conversion that indicates that ambiguity. */
824 build_ambiguous_conv (tree type, tree expr)
828 c = alloc_conversion (ck_ambig);
836 strip_top_quals (tree t)
838 if (TREE_CODE (t) == ARRAY_TYPE)
840 return cp_build_qualified_type (t, 0);
843 /* Returns the standard conversion path (see [conv]) from type FROM to type
844 TO, if any. For proper handling of null pointer constants, you must
845 also pass the expression EXPR to convert from. If C_CAST_P is true,
846 this conversion is coming from a C-style cast. */
849 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
852 enum tree_code fcode, tcode;
854 bool fromref = false;
857 to = non_reference (to);
858 if (TREE_CODE (from) == REFERENCE_TYPE)
861 from = TREE_TYPE (from);
864 to = strip_top_quals (to);
865 from = strip_top_quals (from);
867 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
868 && expr && type_unknown_p (expr))
870 tsubst_flags_t tflags = tf_conv;
871 if (!(flags & LOOKUP_PROTECT))
872 tflags |= tf_no_access_control;
873 expr = instantiate_type (to, expr, tflags);
874 if (expr == error_mark_node)
876 from = TREE_TYPE (expr);
879 fcode = TREE_CODE (from);
880 tcode = TREE_CODE (to);
882 conv = build_identity_conv (from, expr);
883 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
885 from = type_decays_to (from);
886 fcode = TREE_CODE (from);
887 conv = build_conv (ck_lvalue, from, conv);
889 else if (fromref || (expr && lvalue_p (expr)))
894 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
897 from = strip_top_quals (bitfield_type);
898 fcode = TREE_CODE (from);
901 conv = build_conv (ck_rvalue, from, conv);
902 if (flags & LOOKUP_PREFER_RVALUE)
903 conv->rvaluedness_matches_p = true;
906 /* Allow conversion between `__complex__' data types. */
907 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
909 /* The standard conversion sequence to convert FROM to TO is
910 the standard conversion sequence to perform componentwise
912 conversion *part_conv = standard_conversion
913 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
917 conv = build_conv (part_conv->kind, to, conv);
918 conv->rank = part_conv->rank;
926 if (same_type_p (from, to))
928 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
929 conv->type = qualified_to;
934 A null pointer constant can be converted to a pointer type; ... A
935 null pointer constant of integral type can be converted to an
936 rvalue of type std::nullptr_t. */
937 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to)
938 || NULLPTR_TYPE_P (to))
939 && expr && null_ptr_cst_p (expr))
940 conv = build_conv (ck_std, to, conv);
941 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
942 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
944 /* For backwards brain damage compatibility, allow interconversion of
945 pointers and integers with a pedwarn. */
946 conv = build_conv (ck_std, to, conv);
949 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
951 /* For backwards brain damage compatibility, allow interconversion of
952 enums and integers with a pedwarn. */
953 conv = build_conv (ck_std, to, conv);
956 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
957 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
962 if (tcode == POINTER_TYPE
963 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
966 else if (VOID_TYPE_P (TREE_TYPE (to))
967 && !TYPE_PTRMEM_P (from)
968 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
970 tree nfrom = TREE_TYPE (from);
971 from = build_pointer_type
972 (cp_build_qualified_type (void_type_node,
973 cp_type_quals (nfrom)));
974 conv = build_conv (ck_ptr, from, conv);
976 else if (TYPE_PTRMEM_P (from))
978 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
979 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
981 if (DERIVED_FROM_P (fbase, tbase)
982 && (same_type_ignoring_top_level_qualifiers_p
983 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
984 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
986 from = build_ptrmem_type (tbase,
987 TYPE_PTRMEM_POINTED_TO_TYPE (from));
988 conv = build_conv (ck_pmem, from, conv);
990 else if (!same_type_p (fbase, tbase))
993 else if (CLASS_TYPE_P (TREE_TYPE (from))
994 && CLASS_TYPE_P (TREE_TYPE (to))
997 An rvalue of type "pointer to cv D," where D is a
998 class type, can be converted to an rvalue of type
999 "pointer to cv B," where B is a base class (clause
1000 _class.derived_) of D. If B is an inaccessible
1001 (clause _class.access_) or ambiguous
1002 (_class.member.lookup_) base class of D, a program
1003 that necessitates this conversion is ill-formed.
1004 Therefore, we use DERIVED_FROM_P, and do not check
1005 access or uniqueness. */
1006 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
1009 cp_build_qualified_type (TREE_TYPE (to),
1010 cp_type_quals (TREE_TYPE (from)));
1011 from = build_pointer_type (from);
1012 conv = build_conv (ck_ptr, from, conv);
1013 conv->base_p = true;
1016 if (tcode == POINTER_TYPE)
1018 to_pointee = TREE_TYPE (to);
1019 from_pointee = TREE_TYPE (from);
1023 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1024 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1027 if (same_type_p (from, to))
1029 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1030 /* In a C-style cast, we ignore CV-qualification because we
1031 are allowed to perform a static_cast followed by a
1033 conv = build_conv (ck_qual, to, conv);
1034 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1035 conv = build_conv (ck_qual, to, conv);
1036 else if (expr && string_conv_p (to, expr, 0))
1037 /* converting from string constant to char *. */
1038 conv = build_conv (ck_qual, to, conv);
1039 /* Allow conversions among compatible ObjC pointer types (base
1040 conversions have been already handled above). */
1041 else if (c_dialect_objc ()
1042 && objc_compare_types (to, from, -4, NULL_TREE))
1043 conv = build_conv (ck_ptr, to, conv);
1044 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1046 conv = build_conv (ck_ptr, to, conv);
1054 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1056 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1057 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1058 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
1059 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
1061 if (!DERIVED_FROM_P (fbase, tbase)
1062 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
1063 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
1064 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
1065 || cp_type_quals (fbase) != cp_type_quals (tbase))
1068 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase));
1069 from = build_ptrmemfunc_type (build_pointer_type (from));
1070 conv = build_conv (ck_pmem, from, conv);
1071 conv->base_p = true;
1073 else if (tcode == BOOLEAN_TYPE)
1077 An rvalue of arithmetic, unscoped enumeration, pointer, or
1078 pointer to member type can be converted to an rvalue of type
1079 bool. ... An rvalue of type std::nullptr_t can be converted
1080 to an rvalue of type bool; */
1081 if (ARITHMETIC_TYPE_P (from)
1082 || UNSCOPED_ENUM_P (from)
1083 || fcode == POINTER_TYPE
1084 || TYPE_PTR_TO_MEMBER_P (from)
1085 || NULLPTR_TYPE_P (from))
1087 conv = build_conv (ck_std, to, conv);
1088 if (fcode == POINTER_TYPE
1089 || TYPE_PTRMEM_P (from)
1090 || (TYPE_PTRMEMFUNC_P (from)
1091 && conv->rank < cr_pbool)
1092 || NULLPTR_TYPE_P (from))
1093 conv->rank = cr_pbool;
1099 /* We don't check for ENUMERAL_TYPE here because there are no standard
1100 conversions to enum type. */
1101 /* As an extension, allow conversion to complex type. */
1102 else if (ARITHMETIC_TYPE_P (to))
1104 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
1105 || SCOPED_ENUM_P (from))
1107 conv = build_conv (ck_std, to, conv);
1109 /* Give this a better rank if it's a promotion. */
1110 if (same_type_p (to, type_promotes_to (from))
1111 && conv->u.next->rank <= cr_promotion)
1112 conv->rank = cr_promotion;
1114 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1115 && vector_types_convertible_p (from, to, false))
1116 return build_conv (ck_std, to, conv);
1117 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1118 && is_properly_derived_from (from, to))
1120 if (conv->kind == ck_rvalue)
1121 conv = conv->u.next;
1122 conv = build_conv (ck_base, to, conv);
1123 /* The derived-to-base conversion indicates the initialization
1124 of a parameter with base type from an object of a derived
1125 type. A temporary object is created to hold the result of
1126 the conversion unless we're binding directly to a reference. */
1127 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1132 if (flags & LOOKUP_NO_NARROWING)
1133 conv->check_narrowing = true;
1138 /* Returns nonzero if T1 is reference-related to T2. */
1141 reference_related_p (tree t1, tree t2)
1143 if (t1 == error_mark_node || t2 == error_mark_node)
1146 t1 = TYPE_MAIN_VARIANT (t1);
1147 t2 = TYPE_MAIN_VARIANT (t2);
1151 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1152 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1154 return (same_type_p (t1, t2)
1155 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1156 && DERIVED_FROM_P (t1, t2)));
1159 /* Returns nonzero if T1 is reference-compatible with T2. */
1162 reference_compatible_p (tree t1, tree t2)
1166 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1167 reference-related to T2 and cv1 is the same cv-qualification as,
1168 or greater cv-qualification than, cv2. */
1169 return (reference_related_p (t1, t2)
1170 && at_least_as_qualified_p (t1, t2));
1173 /* Determine whether or not the EXPR (of class type S) can be
1174 converted to T as in [over.match.ref]. */
1177 convert_class_to_reference (tree reference_type, tree s, tree expr, int flags)
1183 struct z_candidate *candidates;
1184 struct z_candidate *cand;
1190 conversions = lookup_conversions (s);
1196 Assuming that "cv1 T" is the underlying type of the reference
1197 being initialized, and "cv S" is the type of the initializer
1198 expression, with S a class type, the candidate functions are
1199 selected as follows:
1201 --The conversion functions of S and its base classes are
1202 considered. Those that are not hidden within S and yield type
1203 "reference to cv2 T2", where "cv1 T" is reference-compatible
1204 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1206 The argument list has one argument, which is the initializer
1211 /* Conceptually, we should take the address of EXPR and put it in
1212 the argument list. Unfortunately, however, that can result in
1213 error messages, which we should not issue now because we are just
1214 trying to find a conversion operator. Therefore, we use NULL,
1215 cast to the appropriate type. */
1216 first_arg = build_int_cst (build_pointer_type (s), 0);
1218 t = TREE_TYPE (reference_type);
1220 /* We're performing a user-defined conversion to a desired type, so set
1221 this for the benefit of add_candidates. */
1222 flags |= LOOKUP_NO_CONVERSION;
1224 for (; conversions; conversions = TREE_CHAIN (conversions))
1226 tree fns = TREE_VALUE (conversions);
1227 tree binfo = TREE_PURPOSE (conversions);
1228 struct z_candidate *old_candidates = candidates;;
1230 add_candidates (fns, first_arg, NULL, reference_type,
1232 binfo, TYPE_BINFO (s),
1233 flags, &candidates);
1235 for (cand = candidates; cand != old_candidates; cand = cand->next)
1237 /* Now, see if the conversion function really returns
1238 an lvalue of the appropriate type. From the
1239 point of view of unification, simply returning an
1240 rvalue of the right type is good enough. */
1242 tree t2 = TREE_TYPE (TREE_TYPE (f));
1243 if (cand->viable == 0)
1244 /* Don't bother looking more closely. */;
1245 else if (TREE_CODE (t2) != REFERENCE_TYPE
1246 || !reference_compatible_p (t, TREE_TYPE (t2)))
1248 /* No need to set cand->reason here; this is most likely
1249 an ambiguous match. If it's not, either this candidate
1250 will win, or we will have identified a reason for it
1256 conversion *identity_conv;
1257 /* Build a standard conversion sequence indicating the
1258 binding from the reference type returned by the
1259 function to the desired REFERENCE_TYPE. */
1261 = build_identity_conv (TREE_TYPE (TREE_TYPE
1262 (TREE_TYPE (cand->fn))),
1265 = (direct_reference_binding
1266 (reference_type, identity_conv));
1267 cand->second_conv->rvaluedness_matches_p
1268 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1269 == TYPE_REF_IS_RVALUE (reference_type);
1270 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1272 /* Don't allow binding of lvalues to rvalue references. */
1273 if (TYPE_REF_IS_RVALUE (reference_type)
1274 && !TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn))))
1275 cand->second_conv->bad_p = true;
1280 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1281 /* If none of the conversion functions worked out, let our caller
1286 cand = tourney (candidates);
1290 /* Now that we know that this is the function we're going to use fix
1291 the dummy first argument. */
1292 gcc_assert (cand->first_arg == NULL_TREE
1293 || integer_zerop (cand->first_arg));
1294 cand->first_arg = build_this (expr);
1296 /* Build a user-defined conversion sequence representing the
1298 conv = build_conv (ck_user,
1299 TREE_TYPE (TREE_TYPE (cand->fn)),
1300 build_identity_conv (TREE_TYPE (expr), expr));
1303 if (cand->viable == -1)
1306 /* Merge it with the standard conversion sequence from the
1307 conversion function's return type to the desired type. */
1308 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1310 return cand->second_conv;
1313 /* A reference of the indicated TYPE is being bound directly to the
1314 expression represented by the implicit conversion sequence CONV.
1315 Return a conversion sequence for this binding. */
1318 direct_reference_binding (tree type, conversion *conv)
1322 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1323 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1325 t = TREE_TYPE (type);
1329 When a parameter of reference type binds directly
1330 (_dcl.init.ref_) to an argument expression, the implicit
1331 conversion sequence is the identity conversion, unless the
1332 argument expression has a type that is a derived class of the
1333 parameter type, in which case the implicit conversion sequence is
1334 a derived-to-base Conversion.
1336 If the parameter binds directly to the result of applying a
1337 conversion function to the argument expression, the implicit
1338 conversion sequence is a user-defined conversion sequence
1339 (_over.ics.user_), with the second standard conversion sequence
1340 either an identity conversion or, if the conversion function
1341 returns an entity of a type that is a derived class of the
1342 parameter type, a derived-to-base conversion. */
1343 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1345 /* Represent the derived-to-base conversion. */
1346 conv = build_conv (ck_base, t, conv);
1347 /* We will actually be binding to the base-class subobject in
1348 the derived class, so we mark this conversion appropriately.
1349 That way, convert_like knows not to generate a temporary. */
1350 conv->need_temporary_p = false;
1352 return build_conv (ck_ref_bind, type, conv);
1355 /* Returns the conversion path from type FROM to reference type TO for
1356 purposes of reference binding. For lvalue binding, either pass a
1357 reference type to FROM or an lvalue expression to EXPR. If the
1358 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1359 the conversion returned. If C_CAST_P is true, this
1360 conversion is coming from a C-style cast. */
1363 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1365 conversion *conv = NULL;
1366 tree to = TREE_TYPE (rto);
1371 cp_lvalue_kind is_lvalue = clk_none;
1373 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1375 expr = instantiate_type (to, expr, tf_none);
1376 if (expr == error_mark_node)
1378 from = TREE_TYPE (expr);
1381 if (TREE_CODE (from) == REFERENCE_TYPE)
1383 /* Anything with reference type is an lvalue. */
1384 is_lvalue = clk_ordinary;
1385 from = TREE_TYPE (from);
1388 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1390 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1391 conv = implicit_conversion (to, from, expr, c_cast_p,
1393 if (!CLASS_TYPE_P (to)
1394 && CONSTRUCTOR_NELTS (expr) == 1)
1396 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1397 if (error_operand_p (expr))
1399 from = TREE_TYPE (expr);
1403 if (is_lvalue == clk_none && expr)
1404 is_lvalue = real_lvalue_p (expr);
1407 if ((is_lvalue & clk_bitfield) != 0)
1408 tfrom = unlowered_expr_type (expr);
1410 /* Figure out whether or not the types are reference-related and
1411 reference compatible. We have do do this after stripping
1412 references from FROM. */
1413 related_p = reference_related_p (to, tfrom);
1414 /* If this is a C cast, first convert to an appropriately qualified
1415 type, so that we can later do a const_cast to the desired type. */
1416 if (related_p && c_cast_p
1417 && !at_least_as_qualified_p (to, tfrom))
1418 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1419 compatible_p = reference_compatible_p (to, tfrom);
1421 /* Directly bind reference when target expression's type is compatible with
1422 the reference and expression is an lvalue. In DR391, the wording in
1423 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1424 const and rvalue references to rvalues of compatible class type.
1425 We should also do direct bindings for non-class "rvalues" derived from
1426 rvalue references. */
1429 || (((CP_TYPE_CONST_NON_VOLATILE_P (to)
1430 && !(flags & LOOKUP_NO_TEMP_BIND))
1431 || TYPE_REF_IS_RVALUE (rto))
1432 && (CLASS_TYPE_P (from) || (expr && lvalue_p (expr))))))
1436 If the initializer expression
1438 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1439 is reference-compatible with "cv2 T2,"
1441 the reference is bound directly to the initializer expression
1445 If the initializer expression is an rvalue, with T2 a class type,
1446 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1447 is bound to the object represented by the rvalue or to a sub-object
1448 within that object. */
1450 conv = build_identity_conv (tfrom, expr);
1451 conv = direct_reference_binding (rto, conv);
1453 if (flags & LOOKUP_PREFER_RVALUE)
1454 /* The top-level caller requested that we pretend that the lvalue
1455 be treated as an rvalue. */
1456 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1458 conv->rvaluedness_matches_p
1459 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1461 if ((is_lvalue & clk_bitfield) != 0
1462 || ((is_lvalue & clk_packed) != 0 && !TYPE_PACKED (to)))
1463 /* For the purposes of overload resolution, we ignore the fact
1464 this expression is a bitfield or packed field. (In particular,
1465 [over.ics.ref] says specifically that a function with a
1466 non-const reference parameter is viable even if the
1467 argument is a bitfield.)
1469 However, when we actually call the function we must create
1470 a temporary to which to bind the reference. If the
1471 reference is volatile, or isn't const, then we cannot make
1472 a temporary, so we just issue an error when the conversion
1474 conv->need_temporary_p = true;
1476 /* Don't allow binding of lvalues to rvalue references. */
1477 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1478 && !(flags & LOOKUP_PREFER_RVALUE))
1483 /* [class.conv.fct] A conversion function is never used to convert a
1484 (possibly cv-qualified) object to the (possibly cv-qualified) same
1485 object type (or a reference to it), to a (possibly cv-qualified) base
1486 class of that type (or a reference to it).... */
1487 else if (CLASS_TYPE_P (from) && !related_p
1488 && !(flags & LOOKUP_NO_CONVERSION))
1492 If the initializer expression
1494 -- has a class type (i.e., T2 is a class type) can be
1495 implicitly converted to an lvalue of type "cv3 T3," where
1496 "cv1 T1" is reference-compatible with "cv3 T3". (this
1497 conversion is selected by enumerating the applicable
1498 conversion functions (_over.match.ref_) and choosing the
1499 best one through overload resolution. (_over.match_).
1501 the reference is bound to the lvalue result of the conversion
1502 in the second case. */
1503 conv = convert_class_to_reference (rto, from, expr, flags);
1508 /* From this point on, we conceptually need temporaries, even if we
1509 elide them. Only the cases above are "direct bindings". */
1510 if (flags & LOOKUP_NO_TEMP_BIND)
1515 When a parameter of reference type is not bound directly to an
1516 argument expression, the conversion sequence is the one required
1517 to convert the argument expression to the underlying type of the
1518 reference according to _over.best.ics_. Conceptually, this
1519 conversion sequence corresponds to copy-initializing a temporary
1520 of the underlying type with the argument expression. Any
1521 difference in top-level cv-qualification is subsumed by the
1522 initialization itself and does not constitute a conversion. */
1526 Otherwise, the reference shall be to a non-volatile const type.
1528 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1529 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1534 Otherwise, a temporary of type "cv1 T1" is created and
1535 initialized from the initializer expression using the rules for a
1536 non-reference copy initialization. If T1 is reference-related to
1537 T2, cv1 must be the same cv-qualification as, or greater
1538 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1539 if (related_p && !at_least_as_qualified_p (to, from))
1542 /* We're generating a temporary now, but don't bind any more in the
1543 conversion (specifically, don't slice the temporary returned by a
1544 conversion operator). */
1545 flags |= LOOKUP_NO_TEMP_BIND;
1547 /* Core issue 899: When [copy-]initializing a temporary to be bound
1548 to the first parameter of a copy constructor (12.8) called with
1549 a single argument in the context of direct-initialization,
1550 explicit conversion functions are also considered.
1552 So don't set LOOKUP_ONLYCONVERTING in that case. */
1553 if (!(flags & LOOKUP_COPY_PARM))
1554 flags |= LOOKUP_ONLYCONVERTING;
1557 conv = implicit_conversion (to, from, expr, c_cast_p,
1562 conv = build_conv (ck_ref_bind, rto, conv);
1563 /* This reference binding, unlike those above, requires the
1564 creation of a temporary. */
1565 conv->need_temporary_p = true;
1566 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1571 /* Returns the implicit conversion sequence (see [over.ics]) from type
1572 FROM to type TO. The optional expression EXPR may affect the
1573 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1574 true, this conversion is coming from a C-style cast. */
1577 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1582 if (from == error_mark_node || to == error_mark_node
1583 || expr == error_mark_node)
1586 if (TREE_CODE (to) == REFERENCE_TYPE)
1587 conv = reference_binding (to, from, expr, c_cast_p, flags);
1589 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1594 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1596 if (is_std_init_list (to))
1597 return build_list_conv (to, expr, flags);
1599 /* Allow conversion from an initializer-list with one element to a
1601 if (SCALAR_TYPE_P (to))
1603 int nelts = CONSTRUCTOR_NELTS (expr);
1607 elt = build_value_init (to, tf_none);
1608 else if (nelts == 1)
1609 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1611 elt = error_mark_node;
1613 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1617 conv->check_narrowing = true;
1618 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1619 /* Too many levels of braces, i.e. '{{1}}'. */
1626 if (expr != NULL_TREE
1627 && (MAYBE_CLASS_TYPE_P (from)
1628 || MAYBE_CLASS_TYPE_P (to))
1629 && (flags & LOOKUP_NO_CONVERSION) == 0)
1631 struct z_candidate *cand;
1632 int convflags = (flags & (LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING
1633 |LOOKUP_NO_NARROWING));
1635 if (CLASS_TYPE_P (to)
1636 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1637 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1638 return build_aggr_conv (to, expr, flags);
1640 cand = build_user_type_conversion_1 (to, expr, convflags);
1642 conv = cand->second_conv;
1644 /* We used to try to bind a reference to a temporary here, but that
1645 is now handled after the recursive call to this function at the end
1646 of reference_binding. */
1653 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1654 functions. ARGS will not be changed until a single candidate is
1657 static struct z_candidate *
1658 add_candidate (struct z_candidate **candidates,
1659 tree fn, tree first_arg, const VEC(tree,gc) *args,
1660 size_t num_convs, conversion **convs,
1661 tree access_path, tree conversion_path,
1662 int viable, struct rejection_reason *reason)
1664 struct z_candidate *cand = (struct z_candidate *)
1665 conversion_obstack_alloc (sizeof (struct z_candidate));
1668 cand->first_arg = first_arg;
1670 cand->convs = convs;
1671 cand->num_convs = num_convs;
1672 cand->access_path = access_path;
1673 cand->conversion_path = conversion_path;
1674 cand->viable = viable;
1675 cand->reason = reason;
1676 cand->next = *candidates;
1682 /* Return the number of remaining arguments in the parameter list
1683 beginning with ARG. */
1686 remaining_arguments (tree arg)
1690 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1691 arg = TREE_CHAIN (arg))
1697 /* Create an overload candidate for the function or method FN called
1698 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1699 FLAGS is passed on to implicit_conversion.
1701 This does not change ARGS.
1703 CTYPE, if non-NULL, is the type we want to pretend this function
1704 comes from for purposes of overload resolution. */
1706 static struct z_candidate *
1707 add_function_candidate (struct z_candidate **candidates,
1708 tree fn, tree ctype, tree first_arg,
1709 const VEC(tree,gc) *args, tree access_path,
1710 tree conversion_path, int flags)
1712 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1716 tree orig_first_arg = first_arg;
1719 struct rejection_reason *reason = NULL;
1721 /* At this point we should not see any functions which haven't been
1722 explicitly declared, except for friend functions which will have
1723 been found using argument dependent lookup. */
1724 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1726 /* The `this', `in_chrg' and VTT arguments to constructors are not
1727 considered in overload resolution. */
1728 if (DECL_CONSTRUCTOR_P (fn))
1730 parmlist = skip_artificial_parms_for (fn, parmlist);
1731 skip = num_artificial_parms_for (fn);
1732 if (skip > 0 && first_arg != NULL_TREE)
1735 first_arg = NULL_TREE;
1741 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0);
1742 convs = alloc_conversions (len);
1744 /* 13.3.2 - Viable functions [over.match.viable]
1745 First, to be a viable function, a candidate function shall have enough
1746 parameters to agree in number with the arguments in the list.
1748 We need to check this first; otherwise, checking the ICSes might cause
1749 us to produce an ill-formed template instantiation. */
1751 parmnode = parmlist;
1752 for (i = 0; i < len; ++i)
1754 if (parmnode == NULL_TREE || parmnode == void_list_node)
1756 parmnode = TREE_CHAIN (parmnode);
1759 if ((i < len && parmnode)
1760 || !sufficient_parms_p (parmnode))
1762 int remaining = remaining_arguments (parmnode);
1764 reason = arity_rejection (first_arg, i + remaining, len);
1766 /* When looking for a function from a subobject from an implicit
1767 copy/move constructor/operator=, don't consider anything that takes (a
1768 reference to) an unrelated type. See c++/44909 and core 1092. */
1769 else if (parmlist && (flags & LOOKUP_DEFAULTED))
1771 if (DECL_CONSTRUCTOR_P (fn))
1773 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
1774 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
1780 parmnode = chain_index (i-1, parmlist);
1781 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
1786 /* This only applies at the top level. */
1787 flags &= ~LOOKUP_DEFAULTED;
1793 /* Second, for F to be a viable function, there shall exist for each
1794 argument an implicit conversion sequence that converts that argument
1795 to the corresponding parameter of F. */
1797 parmnode = parmlist;
1799 for (i = 0; i < len; ++i)
1801 tree arg, argtype, to_type;
1805 if (parmnode == void_list_node)
1808 if (i == 0 && first_arg != NULL_TREE)
1811 arg = VEC_index (tree, args,
1812 i + skip - (first_arg != NULL_TREE ? 1 : 0));
1813 argtype = lvalue_type (arg);
1815 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1816 && ! DECL_CONSTRUCTOR_P (fn));
1820 tree parmtype = TREE_VALUE (parmnode);
1823 parmnode = TREE_CHAIN (parmnode);
1825 /* The type of the implicit object parameter ('this') for
1826 overload resolution is not always the same as for the
1827 function itself; conversion functions are considered to
1828 be members of the class being converted, and functions
1829 introduced by a using-declaration are considered to be
1830 members of the class that uses them.
1832 Since build_over_call ignores the ICS for the `this'
1833 parameter, we can just change the parm type. */
1834 if (ctype && is_this)
1836 parmtype = cp_build_qualified_type
1837 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
1838 parmtype = build_pointer_type (parmtype);
1841 /* Core issue 899: When [copy-]initializing a temporary to be bound
1842 to the first parameter of a copy constructor (12.8) called with
1843 a single argument in the context of direct-initialization,
1844 explicit conversion functions are also considered.
1846 So set LOOKUP_COPY_PARM to let reference_binding know that
1847 it's being called in that context. We generalize the above
1848 to handle move constructors and template constructors as well;
1849 the standardese should soon be updated similarly. */
1850 if (ctype && i == 0 && (len-skip == 1)
1851 && !(flags & LOOKUP_ONLYCONVERTING)
1852 && DECL_CONSTRUCTOR_P (fn)
1853 && parmtype != error_mark_node
1854 && (same_type_ignoring_top_level_qualifiers_p
1855 (non_reference (parmtype), ctype)))
1857 lflags |= LOOKUP_COPY_PARM;
1858 /* We allow user-defined conversions within init-lists, but
1859 not for the copy constructor. */
1860 if (flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1861 lflags |= LOOKUP_NO_CONVERSION;
1864 lflags |= LOOKUP_ONLYCONVERTING;
1866 t = implicit_conversion (parmtype, argtype, arg,
1867 /*c_cast_p=*/false, lflags);
1872 t = build_identity_conv (argtype, arg);
1873 t->ellipsis_p = true;
1884 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
1891 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type);
1896 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
1897 access_path, conversion_path, viable, reason);
1900 /* Create an overload candidate for the conversion function FN which will
1901 be invoked for expression OBJ, producing a pointer-to-function which
1902 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1903 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1904 passed on to implicit_conversion.
1906 Actually, we don't really care about FN; we care about the type it
1907 converts to. There may be multiple conversion functions that will
1908 convert to that type, and we rely on build_user_type_conversion_1 to
1909 choose the best one; so when we create our candidate, we record the type
1910 instead of the function. */
1912 static struct z_candidate *
1913 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1914 tree first_arg, const VEC(tree,gc) *arglist,
1915 tree access_path, tree conversion_path)
1917 tree totype = TREE_TYPE (TREE_TYPE (fn));
1918 int i, len, viable, flags;
1919 tree parmlist, parmnode;
1921 struct rejection_reason *reason;
1923 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1924 parmlist = TREE_TYPE (parmlist);
1925 parmlist = TYPE_ARG_TYPES (parmlist);
1927 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1;
1928 convs = alloc_conversions (len);
1929 parmnode = parmlist;
1931 flags = LOOKUP_IMPLICIT;
1934 /* Don't bother looking up the same type twice. */
1935 if (*candidates && (*candidates)->fn == totype)
1938 for (i = 0; i < len; ++i)
1940 tree arg, argtype, convert_type = NULL_TREE;
1945 else if (i == 1 && first_arg != NULL_TREE)
1948 arg = VEC_index (tree, arglist,
1949 i - (first_arg != NULL_TREE ? 1 : 0) - 1);
1950 argtype = lvalue_type (arg);
1954 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
1956 convert_type = totype;
1958 else if (parmnode == void_list_node)
1962 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
1963 /*c_cast_p=*/false, flags);
1964 convert_type = TREE_VALUE (parmnode);
1968 t = build_identity_conv (argtype, arg);
1969 t->ellipsis_p = true;
1970 convert_type = argtype;
1980 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type);
1987 parmnode = TREE_CHAIN (parmnode);
1991 || ! sufficient_parms_p (parmnode))
1993 int remaining = remaining_arguments (parmnode);
1995 reason = arity_rejection (NULL_TREE, i + remaining, len);
1998 return add_candidate (candidates, totype, first_arg, arglist, len, convs,
1999 access_path, conversion_path, viable, reason);
2003 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2004 tree type1, tree type2, tree *args, tree *argtypes,
2012 struct rejection_reason *reason = NULL;
2017 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2018 convs = alloc_conversions (num_convs);
2020 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2021 conversion ops are allowed. We handle that here by just checking for
2022 boolean_type_node because other operators don't ask for it. COND_EXPR
2023 also does contextual conversion to bool for the first operand, but we
2024 handle that in build_conditional_expr, and type1 here is operand 2. */
2025 if (type1 != boolean_type_node)
2026 flags |= LOOKUP_ONLYCONVERTING;
2028 for (i = 0; i < 2; ++i)
2033 t = implicit_conversion (types[i], argtypes[i], args[i],
2034 /*c_cast_p=*/false, flags);
2038 /* We need something for printing the candidate. */
2039 t = build_identity_conv (types[i], NULL_TREE);
2040 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2045 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2050 /* For COND_EXPR we rearranged the arguments; undo that now. */
2053 convs[2] = convs[1];
2054 convs[1] = convs[0];
2055 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2056 /*c_cast_p=*/false, flags);
2062 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2067 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2069 /*access_path=*/NULL_TREE,
2070 /*conversion_path=*/NULL_TREE,
2075 is_complete (tree t)
2077 return COMPLETE_TYPE_P (complete_type (t));
2080 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2083 promoted_arithmetic_type_p (tree type)
2087 In this section, the term promoted integral type is used to refer
2088 to those integral types which are preserved by integral promotion
2089 (including e.g. int and long but excluding e.g. char).
2090 Similarly, the term promoted arithmetic type refers to promoted
2091 integral types plus floating types. */
2092 return ((CP_INTEGRAL_TYPE_P (type)
2093 && same_type_p (type_promotes_to (type), type))
2094 || TREE_CODE (type) == REAL_TYPE);
2097 /* Create any builtin operator overload candidates for the operator in
2098 question given the converted operand types TYPE1 and TYPE2. The other
2099 args are passed through from add_builtin_candidates to
2100 build_builtin_candidate.
2102 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2103 If CODE is requires candidates operands of the same type of the kind
2104 of which TYPE1 and TYPE2 are, we add both candidates
2105 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2108 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2109 enum tree_code code2, tree fnname, tree type1,
2110 tree type2, tree *args, tree *argtypes, int flags)
2114 case POSTINCREMENT_EXPR:
2115 case POSTDECREMENT_EXPR:
2116 args[1] = integer_zero_node;
2117 type2 = integer_type_node;
2126 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2127 and VQ is either volatile or empty, there exist candidate operator
2128 functions of the form
2129 VQ T& operator++(VQ T&);
2130 T operator++(VQ T&, int);
2131 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2132 type other than bool, and VQ is either volatile or empty, there exist
2133 candidate operator functions of the form
2134 VQ T& operator--(VQ T&);
2135 T operator--(VQ T&, int);
2136 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2137 complete object type, and VQ is either volatile or empty, there exist
2138 candidate operator functions of the form
2139 T*VQ& operator++(T*VQ&);
2140 T*VQ& operator--(T*VQ&);
2141 T* operator++(T*VQ&, int);
2142 T* operator--(T*VQ&, int); */
2144 case POSTDECREMENT_EXPR:
2145 case PREDECREMENT_EXPR:
2146 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2148 case POSTINCREMENT_EXPR:
2149 case PREINCREMENT_EXPR:
2150 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2152 type1 = build_reference_type (type1);
2157 /* 7 For every cv-qualified or cv-unqualified object type T, there
2158 exist candidate operator functions of the form
2162 8 For every function type T, there exist candidate operator functions of
2164 T& operator*(T*); */
2167 if (TREE_CODE (type1) == POINTER_TYPE
2168 && !uses_template_parms (TREE_TYPE (type1))
2169 && (TYPE_PTROB_P (type1)
2170 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2174 /* 9 For every type T, there exist candidate operator functions of the form
2177 10For every promoted arithmetic type T, there exist candidate operator
2178 functions of the form
2182 case UNARY_PLUS_EXPR: /* unary + */
2183 if (TREE_CODE (type1) == POINTER_TYPE)
2186 if (ARITHMETIC_TYPE_P (type1))
2190 /* 11For every promoted integral type T, there exist candidate operator
2191 functions of the form
2195 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2199 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2200 is the same type as C2 or is a derived class of C2, T is a complete
2201 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2202 there exist candidate operator functions of the form
2203 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2204 where CV12 is the union of CV1 and CV2. */
2207 if (TREE_CODE (type1) == POINTER_TYPE
2208 && TYPE_PTR_TO_MEMBER_P (type2))
2210 tree c1 = TREE_TYPE (type1);
2211 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2213 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2214 && (TYPE_PTRMEMFUNC_P (type2)
2215 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2220 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2221 didate operator functions of the form
2226 bool operator<(L, R);
2227 bool operator>(L, R);
2228 bool operator<=(L, R);
2229 bool operator>=(L, R);
2230 bool operator==(L, R);
2231 bool operator!=(L, R);
2232 where LR is the result of the usual arithmetic conversions between
2235 14For every pair of types T and I, where T is a cv-qualified or cv-
2236 unqualified complete object type and I is a promoted integral type,
2237 there exist candidate operator functions of the form
2238 T* operator+(T*, I);
2239 T& operator[](T*, I);
2240 T* operator-(T*, I);
2241 T* operator+(I, T*);
2242 T& operator[](I, T*);
2244 15For every T, where T is a pointer to complete object type, there exist
2245 candidate operator functions of the form112)
2246 ptrdiff_t operator-(T, T);
2248 16For every pointer or enumeration type T, there exist candidate operator
2249 functions of the form
2250 bool operator<(T, T);
2251 bool operator>(T, T);
2252 bool operator<=(T, T);
2253 bool operator>=(T, T);
2254 bool operator==(T, T);
2255 bool operator!=(T, T);
2257 17For every pointer to member type T, there exist candidate operator
2258 functions of the form
2259 bool operator==(T, T);
2260 bool operator!=(T, T); */
2263 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2265 if (TYPE_PTROB_P (type1)
2266 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2268 type2 = ptrdiff_type_node;
2272 case TRUNC_DIV_EXPR:
2273 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2279 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2280 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
2282 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
2287 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
2299 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2301 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2303 if (TREE_CODE (type1) == ENUMERAL_TYPE
2304 && TREE_CODE (type2) == ENUMERAL_TYPE)
2306 if (TYPE_PTR_P (type1)
2307 && null_ptr_cst_p (args[1])
2308 && !uses_template_parms (type1))
2313 if (null_ptr_cst_p (args[0])
2314 && TYPE_PTR_P (type2)
2315 && !uses_template_parms (type2))
2323 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2326 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2328 type1 = ptrdiff_type_node;
2331 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2333 type2 = ptrdiff_type_node;
2338 /* 18For every pair of promoted integral types L and R, there exist candi-
2339 date operator functions of the form
2346 where LR is the result of the usual arithmetic conversions between
2349 case TRUNC_MOD_EXPR:
2355 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2359 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2360 type, VQ is either volatile or empty, and R is a promoted arithmetic
2361 type, there exist candidate operator functions of the form
2362 VQ L& operator=(VQ L&, R);
2363 VQ L& operator*=(VQ L&, R);
2364 VQ L& operator/=(VQ L&, R);
2365 VQ L& operator+=(VQ L&, R);
2366 VQ L& operator-=(VQ L&, R);
2368 20For every pair T, VQ), where T is any type and VQ is either volatile
2369 or empty, there exist candidate operator functions of the form
2370 T*VQ& operator=(T*VQ&, T*);
2372 21For every pair T, VQ), where T is a pointer to member type and VQ is
2373 either volatile or empty, there exist candidate operator functions of
2375 VQ T& operator=(VQ T&, T);
2377 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2378 unqualified complete object type, VQ is either volatile or empty, and
2379 I is a promoted integral type, there exist candidate operator func-
2381 T*VQ& operator+=(T*VQ&, I);
2382 T*VQ& operator-=(T*VQ&, I);
2384 23For every triple L, VQ, R), where L is an integral or enumeration
2385 type, VQ is either volatile or empty, and R is a promoted integral
2386 type, there exist candidate operator functions of the form
2388 VQ L& operator%=(VQ L&, R);
2389 VQ L& operator<<=(VQ L&, R);
2390 VQ L& operator>>=(VQ L&, R);
2391 VQ L& operator&=(VQ L&, R);
2392 VQ L& operator^=(VQ L&, R);
2393 VQ L& operator|=(VQ L&, R); */
2400 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2402 type2 = ptrdiff_type_node;
2406 case TRUNC_DIV_EXPR:
2407 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2411 case TRUNC_MOD_EXPR:
2417 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2422 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2424 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2425 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2426 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2427 || ((TYPE_PTRMEMFUNC_P (type1)
2428 || TREE_CODE (type1) == POINTER_TYPE)
2429 && null_ptr_cst_p (args[1])))
2439 type1 = build_reference_type (type1);
2445 For every pair of promoted arithmetic types L and R, there
2446 exist candidate operator functions of the form
2448 LR operator?(bool, L, R);
2450 where LR is the result of the usual arithmetic conversions
2451 between types L and R.
2453 For every type T, where T is a pointer or pointer-to-member
2454 type, there exist candidate operator functions of the form T
2455 operator?(bool, T, T); */
2457 if (promoted_arithmetic_type_p (type1)
2458 && promoted_arithmetic_type_p (type2))
2462 /* Otherwise, the types should be pointers. */
2463 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2464 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2467 /* We don't check that the two types are the same; the logic
2468 below will actually create two candidates; one in which both
2469 parameter types are TYPE1, and one in which both parameter
2477 /* If we're dealing with two pointer types or two enumeral types,
2478 we need candidates for both of them. */
2479 if (type2 && !same_type_p (type1, type2)
2480 && TREE_CODE (type1) == TREE_CODE (type2)
2481 && (TREE_CODE (type1) == REFERENCE_TYPE
2482 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2483 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2484 || TYPE_PTRMEMFUNC_P (type1)
2485 || MAYBE_CLASS_TYPE_P (type1)
2486 || TREE_CODE (type1) == ENUMERAL_TYPE))
2488 build_builtin_candidate
2489 (candidates, fnname, type1, type1, args, argtypes, flags);
2490 build_builtin_candidate
2491 (candidates, fnname, type2, type2, args, argtypes, flags);
2495 build_builtin_candidate
2496 (candidates, fnname, type1, type2, args, argtypes, flags);
2500 type_decays_to (tree type)
2502 if (TREE_CODE (type) == ARRAY_TYPE)
2503 return build_pointer_type (TREE_TYPE (type));
2504 if (TREE_CODE (type) == FUNCTION_TYPE)
2505 return build_pointer_type (type);
2506 if (!MAYBE_CLASS_TYPE_P (type))
2507 type = cv_unqualified (type);
2511 /* There are three conditions of builtin candidates:
2513 1) bool-taking candidates. These are the same regardless of the input.
2514 2) pointer-pair taking candidates. These are generated for each type
2515 one of the input types converts to.
2516 3) arithmetic candidates. According to the standard, we should generate
2517 all of these, but I'm trying not to...
2519 Here we generate a superset of the possible candidates for this particular
2520 case. That is a subset of the full set the standard defines, plus some
2521 other cases which the standard disallows. add_builtin_candidate will
2522 filter out the invalid set. */
2525 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2526 enum tree_code code2, tree fnname, tree *args,
2531 tree type, argtypes[3], t;
2532 /* TYPES[i] is the set of possible builtin-operator parameter types
2533 we will consider for the Ith argument. */
2534 VEC(tree,gc) *types[2];
2537 for (i = 0; i < 3; ++i)
2540 argtypes[i] = unlowered_expr_type (args[i]);
2542 argtypes[i] = NULL_TREE;
2547 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2548 and VQ is either volatile or empty, there exist candidate operator
2549 functions of the form
2550 VQ T& operator++(VQ T&); */
2552 case POSTINCREMENT_EXPR:
2553 case PREINCREMENT_EXPR:
2554 case POSTDECREMENT_EXPR:
2555 case PREDECREMENT_EXPR:
2560 /* 24There also exist candidate operator functions of the form
2561 bool operator!(bool);
2562 bool operator&&(bool, bool);
2563 bool operator||(bool, bool); */
2565 case TRUTH_NOT_EXPR:
2566 build_builtin_candidate
2567 (candidates, fnname, boolean_type_node,
2568 NULL_TREE, args, argtypes, flags);
2571 case TRUTH_ORIF_EXPR:
2572 case TRUTH_ANDIF_EXPR:
2573 build_builtin_candidate
2574 (candidates, fnname, boolean_type_node,
2575 boolean_type_node, args, argtypes, flags);
2597 types[0] = make_tree_vector ();
2598 types[1] = make_tree_vector ();
2600 for (i = 0; i < 2; ++i)
2604 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2608 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2611 convs = lookup_conversions (argtypes[i]);
2613 if (code == COND_EXPR)
2615 if (real_lvalue_p (args[i]))
2616 VEC_safe_push (tree, gc, types[i],
2617 build_reference_type (argtypes[i]));
2619 VEC_safe_push (tree, gc, types[i],
2620 TYPE_MAIN_VARIANT (argtypes[i]));
2626 for (; convs; convs = TREE_CHAIN (convs))
2628 type = TREE_TYPE (convs);
2631 && (TREE_CODE (type) != REFERENCE_TYPE
2632 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2635 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2636 VEC_safe_push (tree, gc, types[i], type);
2638 type = non_reference (type);
2639 if (i != 0 || ! ref1)
2641 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2642 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2643 VEC_safe_push (tree, gc, types[i], type);
2644 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2645 type = type_promotes_to (type);
2648 if (! vec_member (type, types[i]))
2649 VEC_safe_push (tree, gc, types[i], type);
2654 if (code == COND_EXPR && real_lvalue_p (args[i]))
2655 VEC_safe_push (tree, gc, types[i],
2656 build_reference_type (argtypes[i]));
2657 type = non_reference (argtypes[i]);
2658 if (i != 0 || ! ref1)
2660 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2661 if (enum_p && UNSCOPED_ENUM_P (type))
2662 VEC_safe_push (tree, gc, types[i], type);
2663 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2664 type = type_promotes_to (type);
2666 VEC_safe_push (tree, gc, types[i], type);
2670 /* Run through the possible parameter types of both arguments,
2671 creating candidates with those parameter types. */
2672 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t)
2677 if (!VEC_empty (tree, types[1]))
2678 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u)
2679 add_builtin_candidate
2680 (candidates, code, code2, fnname, t,
2681 u, args, argtypes, flags);
2683 add_builtin_candidate
2684 (candidates, code, code2, fnname, t,
2685 NULL_TREE, args, argtypes, flags);
2688 release_tree_vector (types[0]);
2689 release_tree_vector (types[1]);
2693 /* If TMPL can be successfully instantiated as indicated by
2694 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2696 TMPL is the template. EXPLICIT_TARGS are any explicit template
2697 arguments. ARGLIST is the arguments provided at the call-site.
2698 This does not change ARGLIST. The RETURN_TYPE is the desired type
2699 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2700 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2701 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2703 static struct z_candidate*
2704 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2705 tree ctype, tree explicit_targs, tree first_arg,
2706 const VEC(tree,gc) *arglist, tree return_type,
2707 tree access_path, tree conversion_path,
2708 int flags, tree obj, unification_kind_t strict)
2710 int ntparms = DECL_NTPARMS (tmpl);
2711 tree targs = make_tree_vec (ntparms);
2712 unsigned int len = VEC_length (tree, arglist);
2713 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
2714 unsigned int skip_without_in_chrg = 0;
2715 tree first_arg_without_in_chrg = first_arg;
2716 tree *args_without_in_chrg;
2717 unsigned int nargs_without_in_chrg;
2718 unsigned int ia, ix;
2720 struct z_candidate *cand;
2723 struct rejection_reason *reason = NULL;
2725 /* We don't do deduction on the in-charge parameter, the VTT
2726 parameter or 'this'. */
2727 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2729 if (first_arg_without_in_chrg != NULL_TREE)
2730 first_arg_without_in_chrg = NULL_TREE;
2732 ++skip_without_in_chrg;
2735 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2736 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2737 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2739 if (first_arg_without_in_chrg != NULL_TREE)
2740 first_arg_without_in_chrg = NULL_TREE;
2742 ++skip_without_in_chrg;
2745 if (len < skip_without_in_chrg)
2748 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
2749 + (len - skip_without_in_chrg));
2750 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
2752 if (first_arg_without_in_chrg != NULL_TREE)
2754 args_without_in_chrg[ia] = first_arg_without_in_chrg;
2757 for (ix = skip_without_in_chrg;
2758 VEC_iterate (tree, arglist, ix, arg);
2761 args_without_in_chrg[ia] = arg;
2764 gcc_assert (ia == nargs_without_in_chrg);
2766 i = fn_type_unification (tmpl, explicit_targs, targs,
2767 args_without_in_chrg,
2768 nargs_without_in_chrg,
2769 return_type, strict, flags);
2774 fn = instantiate_template (tmpl, targs, tf_none);
2775 if (fn == error_mark_node)
2780 A member function template is never instantiated to perform the
2781 copy of a class object to an object of its class type.
2783 It's a little unclear what this means; the standard explicitly
2784 does allow a template to be used to copy a class. For example,
2789 template <class T> A(const T&);
2792 void g () { A a (f ()); }
2794 the member template will be used to make the copy. The section
2795 quoted above appears in the paragraph that forbids constructors
2796 whose only parameter is (a possibly cv-qualified variant of) the
2797 class type, and a logical interpretation is that the intent was
2798 to forbid the instantiation of member templates which would then
2800 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
2802 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2803 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2808 if (obj != NULL_TREE)
2809 /* Aha, this is a conversion function. */
2810 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist,
2811 access_path, conversion_path);
2813 cand = add_function_candidate (candidates, fn, ctype,
2814 first_arg, arglist, access_path,
2815 conversion_path, flags);
2816 if (DECL_TI_TEMPLATE (fn) != tmpl)
2817 /* This situation can occur if a member template of a template
2818 class is specialized. Then, instantiate_template might return
2819 an instantiation of the specialization, in which case the
2820 DECL_TI_TEMPLATE field will point at the original
2821 specialization. For example:
2823 template <class T> struct S { template <class U> void f(U);
2824 template <> void f(int) {}; };
2828 Here, TMPL will be template <class U> S<double>::f(U).
2829 And, instantiate template will give us the specialization
2830 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2831 for this will point at template <class T> template <> S<T>::f(int),
2832 so that we can find the definition. For the purposes of
2833 overload resolution, however, we want the original TMPL. */
2834 cand->template_decl = build_template_info (tmpl, targs);
2836 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2837 cand->explicit_targs = explicit_targs;
2841 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
2842 access_path, conversion_path, 0, reason);
2846 static struct z_candidate *
2847 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2848 tree explicit_targs, tree first_arg,
2849 const VEC(tree,gc) *arglist, tree return_type,
2850 tree access_path, tree conversion_path, int flags,
2851 unification_kind_t strict)
2854 add_template_candidate_real (candidates, tmpl, ctype,
2855 explicit_targs, first_arg, arglist,
2856 return_type, access_path, conversion_path,
2857 flags, NULL_TREE, strict);
2861 static struct z_candidate *
2862 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2863 tree obj, tree first_arg,
2864 const VEC(tree,gc) *arglist,
2865 tree return_type, tree access_path,
2866 tree conversion_path)
2869 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2870 first_arg, arglist, return_type, access_path,
2871 conversion_path, 0, obj, DEDUCE_CONV);
2874 /* The CANDS are the set of candidates that were considered for
2875 overload resolution. Return the set of viable candidates, or CANDS
2876 if none are viable. If any of the candidates were viable, set
2877 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
2878 considered viable only if it is strictly viable. */
2880 static struct z_candidate*
2881 splice_viable (struct z_candidate *cands,
2885 struct z_candidate *viable;
2886 struct z_candidate **last_viable;
2887 struct z_candidate **cand;
2890 last_viable = &viable;
2891 *any_viable_p = false;
2896 struct z_candidate *c = *cand;
2897 if (strict_p ? c->viable == 1 : c->viable)
2902 last_viable = &c->next;
2903 *any_viable_p = true;
2909 return viable ? viable : cands;
2913 any_strictly_viable (struct z_candidate *cands)
2915 for (; cands; cands = cands->next)
2916 if (cands->viable == 1)
2921 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2922 words, it is about to become the "this" pointer for a member
2923 function call. Take the address of the object. */
2926 build_this (tree obj)
2928 /* In a template, we are only concerned about the type of the
2929 expression, so we can take a shortcut. */
2930 if (processing_template_decl)
2931 return build_address (obj);
2933 return cp_build_addr_expr (obj, tf_warning_or_error);
2936 /* Returns true iff functions are equivalent. Equivalent functions are
2937 not '==' only if one is a function-local extern function or if
2938 both are extern "C". */
2941 equal_functions (tree fn1, tree fn2)
2943 if (TREE_CODE (fn1) != TREE_CODE (fn2))
2945 if (TREE_CODE (fn1) == TEMPLATE_DECL)
2947 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2948 || DECL_EXTERN_C_FUNCTION_P (fn1))
2949 return decls_match (fn1, fn2);
2953 /* Print information about a candidate being rejected due to INFO. */
2956 print_conversion_rejection (location_t loc, struct conversion_info *info)
2958 if (info->n_arg == -1)
2959 /* Conversion of implicit `this' argument failed. */
2960 inform (loc, " no known conversion for implicit "
2961 "%<this%> parameter from %qT to %qT",
2962 info->from_type, info->to_type);
2964 inform (loc, " no known conversion for argument %d from %qT to %qT",
2965 info->n_arg+1, info->from_type, info->to_type);
2968 /* Print information about one overload candidate CANDIDATE. MSGSTR
2969 is the text to print before the candidate itself.
2971 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
2972 to have been run through gettext by the caller. This wart makes
2973 life simpler in print_z_candidates and for the translators. */
2976 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
2978 const char *msg = (msgstr == NULL
2980 : ACONCAT ((msgstr, " ", NULL)));
2981 location_t loc = location_of (candidate->fn);
2983 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
2985 if (candidate->num_convs == 3)
2986 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn,
2987 candidate->convs[0]->type,
2988 candidate->convs[1]->type,
2989 candidate->convs[2]->type);
2990 else if (candidate->num_convs == 2)
2991 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn,
2992 candidate->convs[0]->type,
2993 candidate->convs[1]->type);
2995 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn,
2996 candidate->convs[0]->type);
2998 else if (TYPE_P (candidate->fn))
2999 inform (input_location, "%s%T <conversion>", msg, candidate->fn);
3000 else if (candidate->viable == -1)
3001 inform (loc, "%s%#D <near match>", msg, candidate->fn);
3002 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn)))
3003 inform (loc, "%s%#D <deleted>", msg, candidate->fn);
3005 inform (loc, "%s%#D", msg, candidate->fn);
3006 /* Give the user some information about why this candidate failed. */
3007 if (candidate->reason != NULL)
3009 struct rejection_reason *r = candidate->reason;
3014 inform_n (loc, r->u.arity.expected,
3015 " candidate expects %d argument, %d provided",
3016 " candidate expects %d arguments, %d provided",
3017 r->u.arity.expected, r->u.arity.actual);
3019 case rr_arg_conversion:
3020 print_conversion_rejection (loc, &r->u.conversion);
3022 case rr_bad_arg_conversion:
3023 print_conversion_rejection (loc, &r->u.bad_conversion);
3027 /* This candidate didn't have any issues or we failed to
3028 handle a particular code. Either way... */
3035 print_z_candidates (location_t loc, struct z_candidate *candidates)
3037 struct z_candidate *cand1;
3038 struct z_candidate **cand2;
3044 /* Remove non-viable deleted candidates. */
3046 for (cand2 = &cand1; *cand2; )
3048 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3049 && !(*cand2)->viable
3050 && DECL_DELETED_FN ((*cand2)->fn))
3051 *cand2 = (*cand2)->next;
3053 cand2 = &(*cand2)->next;
3055 /* ...if there are any non-deleted ones. */
3059 /* There may be duplicates in the set of candidates. We put off
3060 checking this condition as long as possible, since we have no way
3061 to eliminate duplicates from a set of functions in less than n^2
3062 time. Now we are about to emit an error message, so it is more
3063 permissible to go slowly. */
3064 for (cand1 = candidates; cand1; cand1 = cand1->next)
3066 tree fn = cand1->fn;
3067 /* Skip builtin candidates and conversion functions. */
3070 cand2 = &cand1->next;
3073 if (DECL_P ((*cand2)->fn)
3074 && equal_functions (fn, (*cand2)->fn))
3075 *cand2 = (*cand2)->next;
3077 cand2 = &(*cand2)->next;
3081 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next)
3084 inform_n (loc, n_candidates, "candidate is:", "candidates are:");
3085 for (; candidates; candidates = candidates->next)
3086 print_z_candidate (NULL, candidates);
3089 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3090 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3091 the result of the conversion function to convert it to the final
3092 desired type. Merge the two sequences into a single sequence,
3093 and return the merged sequence. */
3096 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3100 gcc_assert (user_seq->kind == ck_user);
3102 /* Find the end of the second conversion sequence. */
3104 while ((*t)->kind != ck_identity)
3105 t = &((*t)->u.next);
3107 /* Replace the identity conversion with the user conversion
3111 /* The entire sequence is a user-conversion sequence. */
3112 std_seq->user_conv_p = true;
3117 /* Handle overload resolution for initializing an object of class type from
3118 an initializer list. First we look for a suitable constructor that
3119 takes a std::initializer_list; if we don't find one, we then look for a
3120 non-list constructor.
3122 Parameters are as for add_candidates, except that the arguments are in
3123 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and
3124 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3127 add_list_candidates (tree fns, tree first_arg,
3128 tree init_list, tree totype,
3129 tree explicit_targs, bool template_only,
3130 tree conversion_path, tree access_path,
3132 struct z_candidate **candidates)
3136 gcc_assert (*candidates == NULL);
3138 /* For list-initialization we consider explicit constructors, but
3139 give an error if one is selected. */
3140 flags &= ~LOOKUP_ONLYCONVERTING;
3141 /* And we don't allow narrowing conversions. We also use this flag to
3142 avoid the copy constructor call for copy-list-initialization. */
3143 flags |= LOOKUP_NO_NARROWING;
3145 /* Always use the default constructor if the list is empty (DR 990). */
3146 if (CONSTRUCTOR_NELTS (init_list) == 0
3147 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3149 /* If the class has a list ctor, try passing the list as a single
3150 argument first, but only consider list ctors. */
3151 else if (TYPE_HAS_LIST_CTOR (totype))
3153 flags |= LOOKUP_LIST_ONLY;
3154 args = make_tree_vector_single (init_list);
3155 add_candidates (fns, first_arg, args, NULL_TREE,
3156 explicit_targs, template_only, conversion_path,
3157 access_path, flags, candidates);
3158 if (any_strictly_viable (*candidates))
3162 args = ctor_to_vec (init_list);
3164 /* We aren't looking for list-ctors anymore. */
3165 flags &= ~LOOKUP_LIST_ONLY;
3166 /* We allow more user-defined conversions within an init-list. */
3167 flags &= ~LOOKUP_NO_CONVERSION;
3168 /* But not for the copy ctor. */
3169 flags |= LOOKUP_NO_COPY_CTOR_CONVERSION;
3171 add_candidates (fns, first_arg, args, NULL_TREE,
3172 explicit_targs, template_only, conversion_path,
3173 access_path, flags, candidates);
3176 /* Returns the best overload candidate to perform the requested
3177 conversion. This function is used for three the overloading situations
3178 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3179 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
3180 per [dcl.init.ref], so we ignore temporary bindings. */
3182 static struct z_candidate *
3183 build_user_type_conversion_1 (tree totype, tree expr, int flags)
3185 struct z_candidate *candidates, *cand;
3186 tree fromtype = TREE_TYPE (expr);
3187 tree ctors = NULL_TREE;
3188 tree conv_fns = NULL_TREE;
3189 conversion *conv = NULL;
3190 tree first_arg = NULL_TREE;
3191 VEC(tree,gc) *args = NULL;
3195 /* We represent conversion within a hierarchy using RVALUE_CONV and
3196 BASE_CONV, as specified by [over.best.ics]; these become plain
3197 constructor calls, as specified in [dcl.init]. */
3198 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3199 || !DERIVED_FROM_P (totype, fromtype));
3201 if (MAYBE_CLASS_TYPE_P (totype))
3202 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
3204 if (MAYBE_CLASS_TYPE_P (fromtype))
3206 tree to_nonref = non_reference (totype);
3207 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3208 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3209 && DERIVED_FROM_P (to_nonref, fromtype)))
3211 /* [class.conv.fct] A conversion function is never used to
3212 convert a (possibly cv-qualified) object to the (possibly
3213 cv-qualified) same object type (or a reference to it), to a
3214 (possibly cv-qualified) base class of that type (or a
3215 reference to it)... */
3218 conv_fns = lookup_conversions (fromtype);
3222 flags |= LOOKUP_NO_CONVERSION;
3223 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3224 flags |= LOOKUP_NO_NARROWING;
3226 /* It's OK to bind a temporary for converting constructor arguments, but
3227 not in converting the return value of a conversion operator. */
3228 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
3229 flags &= ~LOOKUP_NO_TEMP_BIND;
3233 int ctorflags = flags;
3234 ctors = BASELINK_FUNCTIONS (ctors);
3236 first_arg = build_int_cst (build_pointer_type (totype), 0);
3238 /* We should never try to call the abstract or base constructor
3240 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
3241 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
3243 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3245 /* List-initialization. */
3246 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE,
3247 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3248 ctorflags, &candidates);
3252 args = make_tree_vector_single (expr);
3253 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3254 TYPE_BINFO (totype), TYPE_BINFO (totype),
3255 ctorflags, &candidates);
3258 for (cand = candidates; cand; cand = cand->next)
3260 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3262 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3263 set, then this is copy-initialization. In that case, "The
3264 result of the call is then used to direct-initialize the
3265 object that is the destination of the copy-initialization."
3268 We represent this in the conversion sequence with an
3269 rvalue conversion, which means a constructor call. */
3270 if (TREE_CODE (totype) != REFERENCE_TYPE
3271 && !(convflags & LOOKUP_NO_TEMP_BIND))
3273 = build_conv (ck_rvalue, totype, cand->second_conv);
3278 first_arg = build_this (expr);
3280 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3282 tree conversion_path = TREE_PURPOSE (conv_fns);
3283 struct z_candidate *old_candidates;
3285 /* If we are called to convert to a reference type, we are trying to
3286 find an lvalue binding, so don't even consider temporaries. If
3287 we don't find an lvalue binding, the caller will try again to
3288 look for a temporary binding. */
3289 if (TREE_CODE (totype) == REFERENCE_TYPE)
3290 convflags |= LOOKUP_NO_TEMP_BIND;
3292 old_candidates = candidates;
3293 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3295 conversion_path, TYPE_BINFO (fromtype),
3296 flags, &candidates);
3298 for (cand = candidates; cand != old_candidates; cand = cand->next)
3301 = implicit_conversion (totype,
3302 TREE_TYPE (TREE_TYPE (cand->fn)),
3304 /*c_cast_p=*/false, convflags);
3306 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3307 copy-initialization. In that case, "The result of the
3308 call is then used to direct-initialize the object that is
3309 the destination of the copy-initialization." [dcl.init]
3311 We represent this in the conversion sequence with an
3312 rvalue conversion, which means a constructor call. But
3313 don't add a second rvalue conversion if there's already
3314 one there. Which there really shouldn't be, but it's
3315 harmless since we'd add it here anyway. */
3316 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3317 && !(convflags & LOOKUP_NO_TEMP_BIND))
3318 ics = build_conv (ck_rvalue, totype, ics);
3320 cand->second_conv = ics;
3324 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3326 cand->reason = arg_conversion_rejection (NULL_TREE, -1,
3329 else if (cand->viable == 1 && ics->bad_p)
3331 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3334 = bad_arg_conversion_rejection (NULL_TREE, -1,
3340 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3344 cand = tourney (candidates);
3347 if (flags & LOOKUP_COMPLAIN)
3349 error ("conversion from %qT to %qT is ambiguous",
3351 print_z_candidates (location_of (expr), candidates);
3354 cand = candidates; /* any one will do */
3355 cand->second_conv = build_ambiguous_conv (totype, expr);
3356 cand->second_conv->user_conv_p = true;
3357 if (!any_strictly_viable (candidates))
3358 cand->second_conv->bad_p = true;
3359 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3360 ambiguous conversion is no worse than another user-defined
3366 /* Build the user conversion sequence. */
3369 (DECL_CONSTRUCTOR_P (cand->fn)
3370 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
3371 build_identity_conv (TREE_TYPE (expr), expr));
3374 /* Remember that this was a list-initialization. */
3375 if (flags & LOOKUP_NO_NARROWING)
3376 conv->check_narrowing = true;
3378 /* Combine it with the second conversion sequence. */
3379 cand->second_conv = merge_conversion_sequences (conv,
3382 if (cand->viable == -1)
3383 cand->second_conv->bad_p = true;
3389 build_user_type_conversion (tree totype, tree expr, int flags)
3391 struct z_candidate *cand
3392 = build_user_type_conversion_1 (totype, expr, flags);
3396 if (cand->second_conv->kind == ck_ambig)
3397 return error_mark_node;
3398 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
3399 return convert_from_reference (expr);
3404 /* Subroutine of convert_nontype_argument.
3406 EXPR is an argument for a template non-type parameter of integral or
3407 enumeration type. Do any necessary conversions (that are permitted for
3408 non-type arguments) to convert it to the parameter type.
3410 If conversion is successful, returns the converted expression;
3411 otherwise, returns error_mark_node. */
3414 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain)
3420 if (error_operand_p (expr))
3421 return error_mark_node;
3423 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3425 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3426 p = conversion_obstack_alloc (0);
3428 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
3432 /* for a non-type template-parameter of integral or
3433 enumeration type, integral promotions (4.5) and integral
3434 conversions (4.7) are applied. */
3435 /* It should be sufficient to check the outermost conversion step, since
3436 there are no qualification conversions to integer type. */
3440 /* A conversion function is OK. If it isn't constexpr, we'll
3441 complain later that the argument isn't constant. */
3443 /* The lvalue-to-rvalue conversion is OK. */
3449 t = conv->u.next->type;
3450 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t))
3453 if (complain & tf_error)
3454 error ("conversion from %qT to %qT not considered for "
3455 "non-type template argument", t, type);
3456 /* and fall through. */
3464 expr = convert_like (conv, expr, complain);
3466 expr = error_mark_node;
3468 /* Free all the conversions we allocated. */
3469 obstack_free (&conversion_obstack, p);
3474 /* Do any initial processing on the arguments to a function call. */
3476 static VEC(tree,gc) *
3477 resolve_args (VEC(tree,gc) *args)
3482 FOR_EACH_VEC_ELT (tree, args, ix, arg)
3484 if (error_operand_p (arg))
3486 else if (VOID_TYPE_P (TREE_TYPE (arg)))
3488 error ("invalid use of void expression");
3491 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
3497 /* Perform overload resolution on FN, which is called with the ARGS.
3499 Return the candidate function selected by overload resolution, or
3500 NULL if the event that overload resolution failed. In the case
3501 that overload resolution fails, *CANDIDATES will be the set of
3502 candidates considered, and ANY_VIABLE_P will be set to true or
3503 false to indicate whether or not any of the candidates were
3506 The ARGS should already have gone through RESOLVE_ARGS before this
3507 function is called. */
3509 static struct z_candidate *
3510 perform_overload_resolution (tree fn,
3511 const VEC(tree,gc) *args,
3512 struct z_candidate **candidates,
3515 struct z_candidate *cand;
3516 tree explicit_targs = NULL_TREE;
3517 int template_only = 0;
3520 *any_viable_p = true;
3523 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
3524 || TREE_CODE (fn) == TEMPLATE_DECL
3525 || TREE_CODE (fn) == OVERLOAD
3526 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3528 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3530 explicit_targs = TREE_OPERAND (fn, 1);
3531 fn = TREE_OPERAND (fn, 0);
3535 /* Add the various candidate functions. */
3536 add_candidates (fn, NULL_TREE, args, NULL_TREE,
3537 explicit_targs, template_only,
3538 /*conversion_path=*/NULL_TREE,
3539 /*access_path=*/NULL_TREE,
3543 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3547 cand = tourney (*candidates);
3551 /* Print an error message about being unable to build a call to FN with
3552 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
3553 be located; CANDIDATES is a possibly empty list of such
3557 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p,
3558 struct z_candidate *candidates)
3560 tree name = DECL_NAME (OVL_CURRENT (fn));
3561 location_t loc = location_of (name);
3564 error_at (loc, "no matching function for call to %<%D(%A)%>",
3565 name, build_tree_list_vec (args));
3567 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
3568 name, build_tree_list_vec (args));
3570 print_z_candidates (loc, candidates);
3573 /* Return an expression for a call to FN (a namespace-scope function,
3574 or a static member function) with the ARGS. This may change
3578 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p,
3579 tsubst_flags_t complain)
3581 struct z_candidate *candidates, *cand;
3586 if (args != NULL && *args != NULL)
3588 *args = resolve_args (*args);
3590 return error_mark_node;
3593 /* If this function was found without using argument dependent
3594 lookup, then we want to ignore any undeclared friend
3600 fn = remove_hidden_names (fn);
3603 if (complain & tf_error)
3604 print_error_for_call_failure (orig_fn, *args, false, NULL);
3605 return error_mark_node;
3609 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3610 p = conversion_obstack_alloc (0);
3612 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p);
3616 if (complain & tf_error)
3618 if (!any_viable_p && candidates && ! candidates->next
3619 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
3620 return cp_build_function_call_vec (candidates->fn, args, complain);
3621 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3622 fn = TREE_OPERAND (fn, 0);
3623 print_error_for_call_failure (fn, *args, any_viable_p, candidates);
3625 result = error_mark_node;
3628 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3630 /* Free all the conversions we allocated. */
3631 obstack_free (&conversion_obstack, p);
3636 /* Build a call to a global operator new. FNNAME is the name of the
3637 operator (either "operator new" or "operator new[]") and ARGS are
3638 the arguments provided. This may change ARGS. *SIZE points to the
3639 total number of bytes required by the allocation, and is updated if
3640 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3641 be used. If this function determines that no cookie should be
3642 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3643 non-NULL, it will be set, upon return, to the allocation function
3647 build_operator_new_call (tree fnname, VEC(tree,gc) **args,
3648 tree *size, tree *cookie_size,
3652 struct z_candidate *candidates;
3653 struct z_candidate *cand;
3658 VEC_safe_insert (tree, gc, *args, 0, *size);
3659 *args = resolve_args (*args);
3661 return error_mark_node;
3667 If this lookup fails to find the name, or if the allocated type
3668 is not a class type, the allocation function's name is looked
3669 up in the global scope.
3671 we disregard block-scope declarations of "operator new". */
3672 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
3674 /* Figure out what function is being called. */
3675 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p);
3677 /* If no suitable function could be found, issue an error message
3681 print_error_for_call_failure (fns, *args, any_viable_p, candidates);
3682 return error_mark_node;
3685 /* If a cookie is required, add some extra space. Whether
3686 or not a cookie is required cannot be determined until
3687 after we know which function was called. */
3690 bool use_cookie = true;
3691 if (!abi_version_at_least (2))
3693 /* In G++ 3.2, the check was implemented incorrectly; it
3694 looked at the placement expression, rather than the
3695 type of the function. */
3696 if (VEC_length (tree, *args) == 2
3697 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)),
3705 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3706 /* Skip the size_t parameter. */
3707 arg_types = TREE_CHAIN (arg_types);
3708 /* Check the remaining parameters (if any). */
3710 && TREE_CHAIN (arg_types) == void_list_node
3711 && same_type_p (TREE_VALUE (arg_types),
3715 /* If we need a cookie, adjust the number of bytes allocated. */
3718 /* Update the total size. */
3719 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3720 /* Update the argument list to reflect the adjusted size. */
3721 VEC_replace (tree, *args, 0, *size);
3724 *cookie_size = NULL_TREE;
3727 /* Tell our caller which function we decided to call. */
3731 /* Build the CALL_EXPR. */
3732 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3735 /* Build a new call to operator(). This may change ARGS. */
3738 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain)
3740 struct z_candidate *candidates = 0, *cand;
3741 tree fns, convs, first_mem_arg = NULL_TREE;
3742 tree type = TREE_TYPE (obj);
3744 tree result = NULL_TREE;
3747 if (error_operand_p (obj))
3748 return error_mark_node;
3750 obj = prep_operand (obj);
3752 if (TYPE_PTRMEMFUNC_P (type))
3754 if (complain & tf_error)
3755 /* It's no good looking for an overloaded operator() on a
3756 pointer-to-member-function. */
3757 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3758 return error_mark_node;
3761 if (TYPE_BINFO (type))
3763 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3764 if (fns == error_mark_node)
3765 return error_mark_node;
3770 if (args != NULL && *args != NULL)
3772 *args = resolve_args (*args);
3774 return error_mark_node;
3777 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3778 p = conversion_obstack_alloc (0);
3782 first_mem_arg = build_this (obj);
3784 add_candidates (BASELINK_FUNCTIONS (fns),
3785 first_mem_arg, *args, NULL_TREE,
3787 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
3788 LOOKUP_NORMAL, &candidates);
3791 convs = lookup_conversions (type);
3793 for (; convs; convs = TREE_CHAIN (convs))
3795 tree fns = TREE_VALUE (convs);
3796 tree totype = TREE_TYPE (convs);
3798 if ((TREE_CODE (totype) == POINTER_TYPE
3799 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3800 || (TREE_CODE (totype) == REFERENCE_TYPE
3801 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3802 || (TREE_CODE (totype) == REFERENCE_TYPE
3803 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3804 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3805 for (; fns; fns = OVL_NEXT (fns))
3807 tree fn = OVL_CURRENT (fns);
3809 if (DECL_NONCONVERTING_P (fn))
3812 if (TREE_CODE (fn) == TEMPLATE_DECL)
3813 add_template_conv_candidate
3814 (&candidates, fn, obj, NULL_TREE, *args, totype,
3815 /*access_path=*/NULL_TREE,
3816 /*conversion_path=*/NULL_TREE);
3818 add_conv_candidate (&candidates, fn, obj, NULL_TREE,
3819 *args, /*conversion_path=*/NULL_TREE,
3820 /*access_path=*/NULL_TREE);
3824 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3827 if (complain & tf_error)
3829 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
3830 build_tree_list_vec (*args));
3831 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3833 result = error_mark_node;
3837 cand = tourney (candidates);
3840 if (complain & tf_error)
3842 error ("call of %<(%T) (%A)%> is ambiguous",
3843 TREE_TYPE (obj), build_tree_list_vec (*args));
3844 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3846 result = error_mark_node;
3848 /* Since cand->fn will be a type, not a function, for a conversion
3849 function, we must be careful not to unconditionally look at
3851 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3852 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3853 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3856 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
3858 obj = convert_from_reference (obj);
3859 result = cp_build_function_call_vec (obj, args, complain);
3863 /* Free all the conversions we allocated. */
3864 obstack_free (&conversion_obstack, p);
3870 op_error (enum tree_code code, enum tree_code code2,
3871 tree arg1, tree arg2, tree arg3, bool match)
3875 if (code == MODIFY_EXPR)
3876 opname = assignment_operator_name_info[code2].name;
3878 opname = operator_name_info[code].name;
3884 error ("ambiguous overload for ternary %<operator?:%> "
3885 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3887 error ("no match for ternary %<operator?:%> "
3888 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3891 case POSTINCREMENT_EXPR:
3892 case POSTDECREMENT_EXPR:
3894 error ("ambiguous overload for %<operator%s%> in %<%E%s%>",
3895 opname, arg1, opname);
3897 error ("no match for %<operator%s%> in %<%E%s%>",
3898 opname, arg1, opname);
3903 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>",
3906 error ("no match for %<operator[]%> in %<%E[%E]%>",
3913 error ("ambiguous overload for %qs in %<%s %E%>",
3914 opname, opname, arg1);
3916 error ("no match for %qs in %<%s %E%>",
3917 opname, opname, arg1);
3923 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>",
3924 opname, arg1, opname, arg2);
3926 error ("no match for %<operator%s%> in %<%E %s %E%>",
3927 opname, arg1, opname, arg2);
3930 error ("ambiguous overload for %<operator%s%> in %<%s%E%>",
3931 opname, opname, arg1);
3933 error ("no match for %<operator%s%> in %<%s%E%>",
3934 opname, opname, arg1);
3939 /* Return the implicit conversion sequence that could be used to
3940 convert E1 to E2 in [expr.cond]. */
3943 conditional_conversion (tree e1, tree e2)
3945 tree t1 = non_reference (TREE_TYPE (e1));
3946 tree t2 = non_reference (TREE_TYPE (e2));
3952 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
3953 implicitly converted (clause _conv_) to the type "reference to
3954 T2", subject to the constraint that in the conversion the
3955 reference must bind directly (_dcl.init.ref_) to E1. */
3956 if (real_lvalue_p (e2))
3958 conv = implicit_conversion (build_reference_type (t2),
3962 LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING);
3969 If E1 and E2 have class type, and the underlying class types are
3970 the same or one is a base class of the other: E1 can be converted
3971 to match E2 if the class of T2 is the same type as, or a base
3972 class of, the class of T1, and the cv-qualification of T2 is the
3973 same cv-qualification as, or a greater cv-qualification than, the
3974 cv-qualification of T1. If the conversion is applied, E1 is
3975 changed to an rvalue of type T2 that still refers to the original
3976 source class object (or the appropriate subobject thereof). */
3977 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
3978 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
3980 if (good_base && at_least_as_qualified_p (t2, t1))
3982 conv = build_identity_conv (t1, e1);
3983 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
3984 TYPE_MAIN_VARIANT (t2)))
3985 conv = build_conv (ck_base, t2, conv);
3987 conv = build_conv (ck_rvalue, t2, conv);
3996 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
3997 converted to the type that expression E2 would have if E2 were
3998 converted to an rvalue (or the type it has, if E2 is an rvalue). */
3999 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4003 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4004 arguments to the conditional expression. */
4007 build_conditional_expr (tree arg1, tree arg2, tree arg3,
4008 tsubst_flags_t complain)
4012 tree result = NULL_TREE;
4013 tree result_type = NULL_TREE;
4014 bool lvalue_p = true;
4015 struct z_candidate *candidates = 0;
4016 struct z_candidate *cand;
4019 /* As a G++ extension, the second argument to the conditional can be
4020 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4021 c'.) If the second operand is omitted, make sure it is
4022 calculated only once. */
4025 if (complain & tf_error)
4026 pedwarn (input_location, OPT_pedantic,
4027 "ISO C++ forbids omitting the middle term of a ?: expression");
4029 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4030 if (real_lvalue_p (arg1))
4031 arg2 = arg1 = stabilize_reference (arg1);
4033 arg2 = arg1 = save_expr (arg1);
4038 The first expression is implicitly converted to bool (clause
4040 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4043 /* If something has already gone wrong, just pass that fact up the
4045 if (error_operand_p (arg1)
4046 || error_operand_p (arg2)
4047 || error_operand_p (arg3))
4048 return error_mark_node;
4052 If either the second or the third operand has type (possibly
4053 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4054 array-to-pointer (_conv.array_), and function-to-pointer
4055 (_conv.func_) standard conversions are performed on the second
4056 and third operands. */
4057 arg2_type = unlowered_expr_type (arg2);
4058 arg3_type = unlowered_expr_type (arg3);
4059 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4061 /* Do the conversions. We don't these for `void' type arguments
4062 since it can't have any effect and since decay_conversion
4063 does not handle that case gracefully. */
4064 if (!VOID_TYPE_P (arg2_type))
4065 arg2 = decay_conversion (arg2);
4066 if (!VOID_TYPE_P (arg3_type))
4067 arg3 = decay_conversion (arg3);
4068 arg2_type = TREE_TYPE (arg2);
4069 arg3_type = TREE_TYPE (arg3);
4073 One of the following shall hold:
4075 --The second or the third operand (but not both) is a
4076 throw-expression (_except.throw_); the result is of the
4077 type of the other and is an rvalue.
4079 --Both the second and the third operands have type void; the
4080 result is of type void and is an rvalue.
4082 We must avoid calling force_rvalue for expressions of type
4083 "void" because it will complain that their value is being
4085 if (TREE_CODE (arg2) == THROW_EXPR
4086 && TREE_CODE (arg3) != THROW_EXPR)
4088 if (!VOID_TYPE_P (arg3_type))
4089 arg3 = force_rvalue (arg3);
4090 arg3_type = TREE_TYPE (arg3);
4091 result_type = arg3_type;
4093 else if (TREE_CODE (arg2) != THROW_EXPR
4094 && TREE_CODE (arg3) == THROW_EXPR)
4096 if (!VOID_TYPE_P (arg2_type))
4097 arg2 = force_rvalue (arg2);
4098 arg2_type = TREE_TYPE (arg2);
4099 result_type = arg2_type;
4101 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
4102 result_type = void_type_node;
4105 if (complain & tf_error)
4107 if (VOID_TYPE_P (arg2_type))
4108 error ("second operand to the conditional operator "
4109 "is of type %<void%>, "
4110 "but the third operand is neither a throw-expression "
4111 "nor of type %<void%>");
4113 error ("third operand to the conditional operator "
4114 "is of type %<void%>, "
4115 "but the second operand is neither a throw-expression "
4116 "nor of type %<void%>");
4118 return error_mark_node;
4122 goto valid_operands;
4126 Otherwise, if the second and third operand have different types,
4127 and either has (possibly cv-qualified) class type, an attempt is
4128 made to convert each of those operands to the type of the other. */
4129 else if (!same_type_p (arg2_type, arg3_type)
4130 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4135 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4136 p = conversion_obstack_alloc (0);
4138 conv2 = conditional_conversion (arg2, arg3);
4139 conv3 = conditional_conversion (arg3, arg2);
4143 If both can be converted, or one can be converted but the
4144 conversion is ambiguous, the program is ill-formed. If
4145 neither can be converted, the operands are left unchanged and
4146 further checking is performed as described below. If exactly
4147 one conversion is possible, that conversion is applied to the
4148 chosen operand and the converted operand is used in place of
4149 the original operand for the remainder of this section. */
4150 if ((conv2 && !conv2->bad_p
4151 && conv3 && !conv3->bad_p)
4152 || (conv2 && conv2->kind == ck_ambig)
4153 || (conv3 && conv3->kind == ck_ambig))
4155 error ("operands to ?: have different types %qT and %qT",
4156 arg2_type, arg3_type);
4157 result = error_mark_node;
4159 else if (conv2 && (!conv2->bad_p || !conv3))
4161 arg2 = convert_like (conv2, arg2, complain);
4162 arg2 = convert_from_reference (arg2);
4163 arg2_type = TREE_TYPE (arg2);
4164 /* Even if CONV2 is a valid conversion, the result of the
4165 conversion may be invalid. For example, if ARG3 has type
4166 "volatile X", and X does not have a copy constructor
4167 accepting a "volatile X&", then even if ARG2 can be
4168 converted to X, the conversion will fail. */
4169 if (error_operand_p (arg2))
4170 result = error_mark_node;
4172 else if (conv3 && (!conv3->bad_p || !conv2))
4174 arg3 = convert_like (conv3, arg3, complain);
4175 arg3 = convert_from_reference (arg3);
4176 arg3_type = TREE_TYPE (arg3);
4177 if (error_operand_p (arg3))
4178 result = error_mark_node;
4181 /* Free all the conversions we allocated. */
4182 obstack_free (&conversion_obstack, p);
4187 /* If, after the conversion, both operands have class type,
4188 treat the cv-qualification of both operands as if it were the
4189 union of the cv-qualification of the operands.
4191 The standard is not clear about what to do in this
4192 circumstance. For example, if the first operand has type
4193 "const X" and the second operand has a user-defined
4194 conversion to "volatile X", what is the type of the second
4195 operand after this step? Making it be "const X" (matching
4196 the first operand) seems wrong, as that discards the
4197 qualification without actually performing a copy. Leaving it
4198 as "volatile X" seems wrong as that will result in the
4199 conditional expression failing altogether, even though,
4200 according to this step, the one operand could be converted to
4201 the type of the other. */
4202 if ((conv2 || conv3)
4203 && CLASS_TYPE_P (arg2_type)
4204 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
4205 arg2_type = arg3_type =
4206 cp_build_qualified_type (arg2_type,
4207 cp_type_quals (arg2_type)
4208 | cp_type_quals (arg3_type));
4213 If the second and third operands are lvalues and have the same
4214 type, the result is of that type and is an lvalue. */
4215 if (real_lvalue_p (arg2)
4216 && real_lvalue_p (arg3)
4217 && same_type_p (arg2_type, arg3_type))
4219 result_type = arg2_type;
4220 arg2 = mark_lvalue_use (arg2);
4221 arg3 = mark_lvalue_use (arg3);
4222 goto valid_operands;
4227 Otherwise, the result is an rvalue. If the second and third
4228 operand do not have the same type, and either has (possibly
4229 cv-qualified) class type, overload resolution is used to
4230 determine the conversions (if any) to be applied to the operands
4231 (_over.match.oper_, _over.built_). */
4233 if (!same_type_p (arg2_type, arg3_type)
4234 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4240 /* Rearrange the arguments so that add_builtin_candidate only has
4241 to know about two args. In build_builtin_candidate, the
4242 arguments are unscrambled. */
4246 add_builtin_candidates (&candidates,
4249 ansi_opname (COND_EXPR),
4255 If the overload resolution fails, the program is
4257 candidates = splice_viable (candidates, pedantic, &any_viable_p);
4260 if (complain & tf_error)
4262 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4263 print_z_candidates (location_of (arg1), candidates);
4265 return error_mark_node;
4267 cand = tourney (candidates);
4270 if (complain & tf_error)
4272 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4273 print_z_candidates (location_of (arg1), candidates);
4275 return error_mark_node;
4280 Otherwise, the conversions thus determined are applied, and
4281 the converted operands are used in place of the original
4282 operands for the remainder of this section. */
4283 conv = cand->convs[0];
4284 arg1 = convert_like (conv, arg1, complain);
4285 conv = cand->convs[1];
4286 arg2 = convert_like (conv, arg2, complain);
4287 arg2_type = TREE_TYPE (arg2);
4288 conv = cand->convs[2];
4289 arg3 = convert_like (conv, arg3, complain);
4290 arg3_type = TREE_TYPE (arg3);
4295 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
4296 and function-to-pointer (_conv.func_) standard conversions are
4297 performed on the second and third operands.
4299 We need to force the lvalue-to-rvalue conversion here for class types,
4300 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
4301 that isn't wrapped with a TARGET_EXPR plays havoc with exception
4304 arg2 = force_rvalue (arg2);
4305 if (!CLASS_TYPE_P (arg2_type))
4306 arg2_type = TREE_TYPE (arg2);
4308 arg3 = force_rvalue (arg3);
4309 if (!CLASS_TYPE_P (arg3_type))
4310 arg3_type = TREE_TYPE (arg3);
4312 if (arg2 == error_mark_node || arg3 == error_mark_node)
4313 return error_mark_node;
4317 After those conversions, one of the following shall hold:
4319 --The second and third operands have the same type; the result is of
4321 if (same_type_p (arg2_type, arg3_type))
4322 result_type = arg2_type;
4325 --The second and third operands have arithmetic or enumeration
4326 type; the usual arithmetic conversions are performed to bring
4327 them to a common type, and the result is of that type. */
4328 else if ((ARITHMETIC_TYPE_P (arg2_type)
4329 || UNSCOPED_ENUM_P (arg2_type))
4330 && (ARITHMETIC_TYPE_P (arg3_type)
4331 || UNSCOPED_ENUM_P (arg3_type)))
4333 /* In this case, there is always a common type. */
4334 result_type = type_after_usual_arithmetic_conversions (arg2_type,
4336 do_warn_double_promotion (result_type, arg2_type, arg3_type,
4337 "implicit conversion from %qT to %qT to "
4338 "match other result of conditional",
4341 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
4342 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
4344 if (complain & tf_warning)
4346 "enumeral mismatch in conditional expression: %qT vs %qT",
4347 arg2_type, arg3_type);
4349 else if (extra_warnings
4350 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
4351 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
4352 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
4353 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
4355 if (complain & tf_warning)
4357 "enumeral and non-enumeral type in conditional expression");
4360 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4361 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4365 --The second and third operands have pointer type, or one has
4366 pointer type and the other is a null pointer constant; pointer
4367 conversions (_conv.ptr_) and qualification conversions
4368 (_conv.qual_) are performed to bring them to their composite
4369 pointer type (_expr.rel_). The result is of the composite
4372 --The second and third operands have pointer to member type, or
4373 one has pointer to member type and the other is a null pointer
4374 constant; pointer to member conversions (_conv.mem_) and
4375 qualification conversions (_conv.qual_) are performed to bring
4376 them to a common type, whose cv-qualification shall match the
4377 cv-qualification of either the second or the third operand.
4378 The result is of the common type. */
4379 else if ((null_ptr_cst_p (arg2)
4380 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
4381 || (null_ptr_cst_p (arg3)
4382 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
4383 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
4384 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
4385 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
4387 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
4388 arg3, CPO_CONDITIONAL_EXPR,
4390 if (result_type == error_mark_node)
4391 return error_mark_node;
4392 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4393 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4398 if (complain & tf_error)
4399 error ("operands to ?: have different types %qT and %qT",
4400 arg2_type, arg3_type);
4401 return error_mark_node;
4405 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3);
4406 if (!cp_unevaluated_operand)
4407 /* Avoid folding within decltype (c++/42013) and noexcept. */
4408 result = fold_if_not_in_template (result);
4410 /* We can't use result_type below, as fold might have returned a
4415 /* Expand both sides into the same slot, hopefully the target of
4416 the ?: expression. We used to check for TARGET_EXPRs here,
4417 but now we sometimes wrap them in NOP_EXPRs so the test would
4419 if (CLASS_TYPE_P (TREE_TYPE (result)))
4420 result = get_target_expr (result);
4421 /* If this expression is an rvalue, but might be mistaken for an
4422 lvalue, we must add a NON_LVALUE_EXPR. */
4423 result = rvalue (result);
4429 /* OPERAND is an operand to an expression. Perform necessary steps
4430 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4434 prep_operand (tree operand)
4438 if (CLASS_TYPE_P (TREE_TYPE (operand))
4439 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
4440 /* Make sure the template type is instantiated now. */
4441 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
4447 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4448 OVERLOAD) to the CANDIDATES, returning an updated list of
4449 CANDIDATES. The ARGS are the arguments provided to the call;
4450 if FIRST_ARG is non-null it is the implicit object argument,
4451 otherwise the first element of ARGS is used if needed. The
4452 EXPLICIT_TARGS are explicit template arguments provided.
4453 TEMPLATE_ONLY is true if only template functions should be
4454 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4455 add_function_candidate. */
4458 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args,
4460 tree explicit_targs, bool template_only,
4461 tree conversion_path, tree access_path,
4463 struct z_candidate **candidates)
4466 const VEC(tree,gc) *non_static_args;
4467 bool check_list_ctor;
4468 bool check_converting;
4469 unification_kind_t strict;
4475 /* Precalculate special handling of constructors and conversion ops. */
4476 fn = OVL_CURRENT (fns);
4477 if (DECL_CONV_FN_P (fn))
4479 check_list_ctor = false;
4480 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4481 if (flags & LOOKUP_NO_CONVERSION)
4482 /* We're doing return_type(x). */
4483 strict = DEDUCE_CONV;
4485 /* We're doing x.operator return_type(). */
4486 strict = DEDUCE_EXACT;
4487 /* [over.match.funcs] For conversion functions, the function
4488 is considered to be a member of the class of the implicit
4489 object argument for the purpose of defining the type of
4490 the implicit object parameter. */
4491 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg)));
4495 if (DECL_CONSTRUCTOR_P (fn))
4497 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY);
4498 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4502 check_list_ctor = false;
4503 check_converting = false;
4505 strict = DEDUCE_CALL;
4506 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
4510 non_static_args = args;
4512 /* Delay creating the implicit this parameter until it is needed. */
4513 non_static_args = NULL;
4515 for (; fns; fns = OVL_NEXT (fns))
4518 const VEC(tree,gc) *fn_args;
4520 fn = OVL_CURRENT (fns);
4522 if (check_converting && DECL_NONCONVERTING_P (fn))
4524 if (check_list_ctor && !is_list_ctor (fn))
4527 /* Figure out which set of arguments to use. */
4528 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
4530 /* If this function is a non-static member and we didn't get an
4531 implicit object argument, move it out of args. */
4532 if (first_arg == NULL_TREE)
4536 VEC(tree,gc) *tempvec
4537 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1);
4538 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix)
4539 VEC_quick_push (tree, tempvec, arg);
4540 non_static_args = tempvec;
4541 first_arg = build_this (VEC_index (tree, args, 0));
4544 fn_first_arg = first_arg;
4545 fn_args = non_static_args;
4549 /* Otherwise, just use the list of arguments provided. */
4550 fn_first_arg = NULL_TREE;
4554 if (TREE_CODE (fn) == TEMPLATE_DECL)
4555 add_template_candidate (candidates,
4566 else if (!template_only)
4567 add_function_candidate (candidates,
4578 /* Even unsigned enum types promote to signed int. We don't want to
4579 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4580 original argument and ARG is the argument after any conversions
4581 have been applied. We set TREE_NO_WARNING if we have added a cast
4582 from an unsigned enum type to a signed integer type. */
4585 avoid_sign_compare_warnings (tree orig_arg, tree arg)
4587 if (orig_arg != NULL_TREE
4590 && TREE_CODE (TREE_TYPE (orig_arg)) == ENUMERAL_TYPE
4591 && TYPE_UNSIGNED (TREE_TYPE (orig_arg))
4592 && INTEGRAL_TYPE_P (TREE_TYPE (arg))
4593 && !TYPE_UNSIGNED (TREE_TYPE (arg)))
4594 TREE_NO_WARNING (arg) = 1;
4598 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
4599 bool *overloaded_p, tsubst_flags_t complain)
4601 tree orig_arg1 = arg1;
4602 tree orig_arg2 = arg2;
4603 tree orig_arg3 = arg3;
4604 struct z_candidate *candidates = 0, *cand;
4605 VEC(tree,gc) *arglist;
4608 tree result = NULL_TREE;
4609 bool result_valid_p = false;
4610 enum tree_code code2 = NOP_EXPR;
4611 enum tree_code code_orig_arg1 = ERROR_MARK;
4612 enum tree_code code_orig_arg2 = ERROR_MARK;
4618 if (error_operand_p (arg1)
4619 || error_operand_p (arg2)
4620 || error_operand_p (arg3))
4621 return error_mark_node;
4623 if (code == MODIFY_EXPR)
4625 code2 = TREE_CODE (arg3);
4627 fnname = ansi_assopname (code2);
4630 fnname = ansi_opname (code);
4632 arg1 = prep_operand (arg1);
4638 case VEC_DELETE_EXPR:
4640 /* Use build_op_new_call and build_op_delete_call instead. */
4644 /* Use build_op_call instead. */
4647 case TRUTH_ORIF_EXPR:
4648 case TRUTH_ANDIF_EXPR:
4649 case TRUTH_AND_EXPR:
4651 /* These are saved for the sake of warn_logical_operator. */
4652 code_orig_arg1 = TREE_CODE (arg1);
4653 code_orig_arg2 = TREE_CODE (arg2);
4659 arg2 = prep_operand (arg2);
4660 arg3 = prep_operand (arg3);
4662 if (code == COND_EXPR)
4663 /* Use build_conditional_expr instead. */
4665 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
4666 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4669 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4670 arg2 = integer_zero_node;
4672 arglist = VEC_alloc (tree, gc, 3);
4673 VEC_quick_push (tree, arglist, arg1);
4674 if (arg2 != NULL_TREE)
4675 VEC_quick_push (tree, arglist, arg2);
4676 if (arg3 != NULL_TREE)
4677 VEC_quick_push (tree, arglist, arg3);
4679 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4680 p = conversion_obstack_alloc (0);
4682 /* Add namespace-scope operators to the list of functions to
4684 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4685 NULL_TREE, arglist, NULL_TREE,
4686 NULL_TREE, false, NULL_TREE, NULL_TREE,
4687 flags, &candidates);
4688 /* Add class-member operators to the candidate set. */
4689 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4693 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4694 if (fns == error_mark_node)
4696 result = error_mark_node;
4697 goto user_defined_result_ready;
4700 add_candidates (BASELINK_FUNCTIONS (fns),
4701 NULL_TREE, arglist, NULL_TREE,
4703 BASELINK_BINFO (fns),
4704 BASELINK_ACCESS_BINFO (fns),
4705 flags, &candidates);
4710 args[2] = NULL_TREE;
4712 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4718 /* For these, the built-in candidates set is empty
4719 [over.match.oper]/3. We don't want non-strict matches
4720 because exact matches are always possible with built-in
4721 operators. The built-in candidate set for COMPONENT_REF
4722 would be empty too, but since there are no such built-in
4723 operators, we accept non-strict matches for them. */
4728 strict_p = pedantic;
4732 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4737 case POSTINCREMENT_EXPR:
4738 case POSTDECREMENT_EXPR:
4739 /* Don't try anything fancy if we're not allowed to produce
4741 if (!(complain & tf_error))
4742 return error_mark_node;
4744 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4745 distinguish between prefix and postfix ++ and
4746 operator++() was used for both, so we allow this with
4748 if (flags & LOOKUP_COMPLAIN)
4750 const char *msg = (flag_permissive)
4751 ? G_("no %<%D(int)%> declared for postfix %qs,"
4752 " trying prefix operator instead")
4753 : G_("no %<%D(int)%> declared for postfix %qs");
4754 permerror (input_location, msg, fnname,
4755 operator_name_info[code].name);
4758 if (!flag_permissive)
4759 return error_mark_node;
4761 if (code == POSTINCREMENT_EXPR)
4762 code = PREINCREMENT_EXPR;
4764 code = PREDECREMENT_EXPR;
4765 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
4766 overloaded_p, complain);
4769 /* The caller will deal with these. */
4774 result_valid_p = true;
4778 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4780 /* If one of the arguments of the operator represents
4781 an invalid use of member function pointer, try to report
4782 a meaningful error ... */
4783 if (invalid_nonstatic_memfn_p (arg1, tf_error)
4784 || invalid_nonstatic_memfn_p (arg2, tf_error)
4785 || invalid_nonstatic_memfn_p (arg3, tf_error))
4786 /* We displayed the error message. */;
4789 /* ... Otherwise, report the more generic
4790 "no matching operator found" error */
4791 op_error (code, code2, arg1, arg2, arg3, FALSE);
4792 print_z_candidates (input_location, candidates);
4795 result = error_mark_node;
4801 cand = tourney (candidates);
4804 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4806 op_error (code, code2, arg1, arg2, arg3, TRUE);
4807 print_z_candidates (input_location, candidates);
4809 result = error_mark_node;
4811 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4814 *overloaded_p = true;
4816 if (resolve_args (arglist) == NULL)
4817 result = error_mark_node;
4819 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4823 /* Give any warnings we noticed during overload resolution. */
4824 if (cand->warnings && (complain & tf_warning))
4826 struct candidate_warning *w;
4827 for (w = cand->warnings; w; w = w->next)
4828 joust (cand, w->loser, 1);
4831 /* Check for comparison of different enum types. */
4840 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
4841 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
4842 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
4843 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
4844 && (complain & tf_warning))
4846 warning (OPT_Wenum_compare,
4847 "comparison between %q#T and %q#T",
4848 TREE_TYPE (arg1), TREE_TYPE (arg2));
4855 /* We need to strip any leading REF_BIND so that bitfields
4856 don't cause errors. This should not remove any important
4857 conversions, because builtins don't apply to class
4858 objects directly. */
4859 conv = cand->convs[0];
4860 if (conv->kind == ck_ref_bind)
4861 conv = conv->u.next;
4862 arg1 = convert_like (conv, arg1, complain);
4866 /* We need to call warn_logical_operator before
4867 converting arg2 to a boolean_type. */
4868 if (complain & tf_warning)
4869 warn_logical_operator (input_location, code, boolean_type_node,
4870 code_orig_arg1, arg1,
4871 code_orig_arg2, arg2);
4873 conv = cand->convs[1];
4874 if (conv->kind == ck_ref_bind)
4875 conv = conv->u.next;
4876 arg2 = convert_like (conv, arg2, complain);
4880 conv = cand->convs[2];
4881 if (conv->kind == ck_ref_bind)
4882 conv = conv->u.next;
4883 arg3 = convert_like (conv, arg3, complain);
4889 user_defined_result_ready:
4891 /* Free all the conversions we allocated. */
4892 obstack_free (&conversion_obstack, p);
4894 if (result || result_valid_p)
4898 avoid_sign_compare_warnings (orig_arg1, arg1);
4899 avoid_sign_compare_warnings (orig_arg2, arg2);
4900 avoid_sign_compare_warnings (orig_arg3, arg3);
4905 return cp_build_modify_expr (arg1, code2, arg2, complain);
4908 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
4910 case TRUTH_ANDIF_EXPR:
4911 case TRUTH_ORIF_EXPR:
4912 case TRUTH_AND_EXPR:
4914 warn_logical_operator (input_location, code, boolean_type_node,
4915 code_orig_arg1, arg1, code_orig_arg2, arg2);
4920 case TRUNC_DIV_EXPR:
4931 case TRUNC_MOD_EXPR:
4935 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
4937 case UNARY_PLUS_EXPR:
4940 case TRUTH_NOT_EXPR:
4941 case PREINCREMENT_EXPR:
4942 case POSTINCREMENT_EXPR:
4943 case PREDECREMENT_EXPR:
4944 case POSTDECREMENT_EXPR:
4947 return cp_build_unary_op (code, arg1, candidates != 0, complain);
4950 return cp_build_array_ref (input_location, arg1, arg2, complain);
4953 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL,
4957 /* The caller will deal with these. */
4969 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
4970 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
4973 non_placement_deallocation_fn_p (tree t)
4975 /* A template instance is never a usual deallocation function,
4976 regardless of its signature. */
4977 if (TREE_CODE (t) == TEMPLATE_DECL
4978 || primary_template_instantiation_p (t))
4981 /* If a class T has a member deallocation function named operator delete
4982 with exactly one parameter, then that function is a usual
4983 (non-placement) deallocation function. If class T does not declare
4984 such an operator delete but does declare a member deallocation
4985 function named operator delete with exactly two parameters, the second
4986 of which has type std::size_t (18.2), then this function is a usual
4987 deallocation function. */
4988 t = FUNCTION_ARG_CHAIN (t);
4989 if (t == void_list_node
4990 || (t && same_type_p (TREE_VALUE (t), size_type_node)
4991 && TREE_CHAIN (t) == void_list_node))
4996 /* Build a call to operator delete. This has to be handled very specially,
4997 because the restrictions on what signatures match are different from all
4998 other call instances. For a normal delete, only a delete taking (void *)
4999 or (void *, size_t) is accepted. For a placement delete, only an exact
5000 match with the placement new is accepted.
5002 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
5003 ADDR is the pointer to be deleted.
5004 SIZE is the size of the memory block to be deleted.
5005 GLOBAL_P is true if the delete-expression should not consider
5006 class-specific delete operators.
5007 PLACEMENT is the corresponding placement new call, or NULL_TREE.
5009 If this call to "operator delete" is being generated as part to
5010 deallocate memory allocated via a new-expression (as per [expr.new]
5011 which requires that if the initialization throws an exception then
5012 we call a deallocation function), then ALLOC_FN is the allocation
5016 build_op_delete_call (enum tree_code code, tree addr, tree size,
5017 bool global_p, tree placement,
5020 tree fn = NULL_TREE;
5021 tree fns, fnname, type, t;
5023 if (addr == error_mark_node)
5024 return error_mark_node;
5026 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
5028 fnname = ansi_opname (code);
5030 if (CLASS_TYPE_P (type)
5031 && COMPLETE_TYPE_P (complete_type (type))
5035 If the result of the lookup is ambiguous or inaccessible, or if
5036 the lookup selects a placement deallocation function, the
5037 program is ill-formed.
5039 Therefore, we ask lookup_fnfields to complain about ambiguity. */
5041 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
5042 if (fns == error_mark_node)
5043 return error_mark_node;
5048 if (fns == NULL_TREE)
5049 fns = lookup_name_nonclass (fnname);
5051 /* Strip const and volatile from addr. */
5052 addr = cp_convert (ptr_type_node, addr);
5056 /* "A declaration of a placement deallocation function matches the
5057 declaration of a placement allocation function if it has the same
5058 number of parameters and, after parameter transformations (8.3.5),
5059 all parameter types except the first are identical."
5061 So we build up the function type we want and ask instantiate_type
5062 to get it for us. */
5063 t = FUNCTION_ARG_CHAIN (alloc_fn);
5064 t = tree_cons (NULL_TREE, ptr_type_node, t);
5065 t = build_function_type (void_type_node, t);
5067 fn = instantiate_type (t, fns, tf_none);
5068 if (fn == error_mark_node)
5071 if (BASELINK_P (fn))
5072 fn = BASELINK_FUNCTIONS (fn);
5074 /* "If the lookup finds the two-parameter form of a usual deallocation
5075 function (3.7.4.2) and that function, considered as a placement
5076 deallocation function, would have been selected as a match for the
5077 allocation function, the program is ill-formed." */
5078 if (non_placement_deallocation_fn_p (fn))
5080 /* But if the class has an operator delete (void *), then that is
5081 the usual deallocation function, so we shouldn't complain
5082 about using the operator delete (void *, size_t). */
5083 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5084 t; t = OVL_NEXT (t))
5086 tree elt = OVL_CURRENT (t);
5087 if (non_placement_deallocation_fn_p (elt)
5088 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
5091 permerror (0, "non-placement deallocation function %q+D", fn);
5092 permerror (input_location, "selected for placement delete");
5097 /* "Any non-placement deallocation function matches a non-placement
5098 allocation function. If the lookup finds a single matching
5099 deallocation function, that function will be called; otherwise, no
5100 deallocation function will be called." */
5101 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5102 t; t = OVL_NEXT (t))
5104 tree elt = OVL_CURRENT (t);
5105 if (non_placement_deallocation_fn_p (elt))
5108 /* "If a class T has a member deallocation function named
5109 operator delete with exactly one parameter, then that
5110 function is a usual (non-placement) deallocation
5111 function. If class T does not declare such an operator
5112 delete but does declare a member deallocation function named
5113 operator delete with exactly two parameters, the second of
5114 which has type std::size_t (18.2), then this function is a
5115 usual deallocation function."
5117 So (void*) beats (void*, size_t). */
5118 if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
5123 /* If we have a matching function, call it. */
5126 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5128 /* If the FN is a member function, make sure that it is
5130 if (BASELINK_P (fns))
5131 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn);
5133 /* Core issue 901: It's ok to new a type with deleted delete. */
5134 if (DECL_DELETED_FN (fn) && alloc_fn)
5139 /* The placement args might not be suitable for overload
5140 resolution at this point, so build the call directly. */
5141 int nargs = call_expr_nargs (placement);
5142 tree *argarray = XALLOCAVEC (tree, nargs);
5145 for (i = 1; i < nargs; i++)
5146 argarray[i] = CALL_EXPR_ARG (placement, i);
5148 return build_cxx_call (fn, nargs, argarray);
5153 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2);
5154 VEC_quick_push (tree, args, addr);
5155 if (FUNCTION_ARG_CHAIN (fn) != void_list_node)
5156 VEC_quick_push (tree, args, size);
5157 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error);
5158 VEC_free (tree, gc, args);
5165 If no unambiguous matching deallocation function can be found,
5166 propagating the exception does not cause the object's memory to
5171 warning (0, "no corresponding deallocation function for %qD",
5176 error ("no suitable %<operator %s%> for %qT",
5177 operator_name_info[(int)code].name, type);
5178 return error_mark_node;
5181 /* If the current scope isn't allowed to access DECL along
5182 BASETYPE_PATH, give an error. The most derived class in
5183 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
5184 the declaration to use in the error diagnostic. */
5187 enforce_access (tree basetype_path, tree decl, tree diag_decl)
5189 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
5191 if (!accessible_p (basetype_path, decl, true))
5193 if (TREE_PRIVATE (decl))
5194 error ("%q+#D is private", diag_decl);
5195 else if (TREE_PROTECTED (decl))
5196 error ("%q+#D is protected", diag_decl);
5198 error ("%q+#D is inaccessible", diag_decl);
5199 error ("within this context");
5206 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
5207 bitwise or of LOOKUP_* values. If any errors are warnings are
5208 generated, set *DIAGNOSTIC_FN to "error" or "warning",
5209 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
5213 build_temp (tree expr, tree type, int flags,
5214 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
5219 savew = warningcount, savee = errorcount;
5220 args = make_tree_vector_single (expr);
5221 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
5222 &args, type, flags, complain);
5223 release_tree_vector (args);
5224 if (warningcount > savew)
5225 *diagnostic_kind = DK_WARNING;
5226 else if (errorcount > savee)
5227 *diagnostic_kind = DK_ERROR;
5229 *diagnostic_kind = DK_UNSPECIFIED;
5233 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
5234 EXPR is implicitly converted to type TOTYPE.
5235 FN and ARGNUM are used for diagnostics. */
5238 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
5240 tree t = non_reference (totype);
5242 /* Issue warnings about peculiar, but valid, uses of NULL. */
5243 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
5246 warning_at (input_location, OPT_Wconversion_null,
5247 "passing NULL to non-pointer argument %P of %qD",
5250 warning_at (input_location, OPT_Wconversion_null,
5251 "converting to non-pointer type %qT from NULL", t);
5254 /* Issue warnings if "false" is converted to a NULL pointer */
5255 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
5256 warning_at (input_location, OPT_Wconversion_null,
5257 "converting %<false%> to pointer type for argument %P of %qD",
5261 /* Perform the conversions in CONVS on the expression EXPR. FN and
5262 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
5263 indicates the `this' argument of a method. INNER is nonzero when
5264 being called to continue a conversion chain. It is negative when a
5265 reference binding will be applied, positive otherwise. If
5266 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
5267 conversions will be emitted if appropriate. If C_CAST_P is true,
5268 this conversion is coming from a C-style cast; in that case,
5269 conversions to inaccessible bases are permitted. */
5272 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
5273 int inner, bool issue_conversion_warnings,
5274 bool c_cast_p, tsubst_flags_t complain)
5276 tree totype = convs->type;
5277 diagnostic_t diag_kind;
5281 && convs->kind != ck_user
5282 && convs->kind != ck_list
5283 && convs->kind != ck_ambig
5284 && convs->kind != ck_ref_bind
5285 && convs->kind != ck_rvalue
5286 && convs->kind != ck_base)
5288 conversion *t = convs;
5290 /* Give a helpful error if this is bad because of excess braces. */
5291 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
5292 && SCALAR_TYPE_P (totype)
5293 && CONSTRUCTOR_NELTS (expr) > 0
5294 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
5295 permerror (input_location, "too many braces around initializer for %qT", totype);
5297 for (; t; t = convs->u.next)
5299 if (t->kind == ck_user || !t->bad_p)
5301 expr = convert_like_real (t, expr, fn, argnum, 1,
5302 /*issue_conversion_warnings=*/false,
5307 else if (t->kind == ck_ambig)
5308 return convert_like_real (t, expr, fn, argnum, 1,
5309 /*issue_conversion_warnings=*/false,
5312 else if (t->kind == ck_identity)
5315 if (complain & tf_error)
5317 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
5319 permerror (DECL_SOURCE_LOCATION (fn),
5320 " initializing argument %P of %qD", argnum, fn);
5323 return error_mark_node;
5325 return cp_convert (totype, expr);
5328 if (issue_conversion_warnings && (complain & tf_warning))
5329 conversion_null_warnings (totype, expr, fn, argnum);
5331 switch (convs->kind)
5335 struct z_candidate *cand = convs->cand;
5336 tree convfn = cand->fn;
5339 expr = mark_rvalue_use (expr);
5341 /* When converting from an init list we consider explicit
5342 constructors, but actually trying to call one is an error. */
5343 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
5344 /* Unless we're calling it for value-initialization from an
5345 empty list, since that is handled separately in 8.5.4. */
5346 && cand->num_convs > 0)
5348 if (complain & tf_error)
5349 error ("converting to %qT from initializer list would use "
5350 "explicit constructor %qD", totype, convfn);
5352 return error_mark_node;
5355 /* Set user_conv_p on the argument conversions, so rvalue/base
5356 handling knows not to allow any more UDCs. */
5357 for (i = 0; i < cand->num_convs; ++i)
5358 cand->convs[i]->user_conv_p = true;
5360 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
5362 /* If this is a constructor or a function returning an aggr type,
5363 we need to build up a TARGET_EXPR. */
5364 if (DECL_CONSTRUCTOR_P (convfn))
5366 expr = build_cplus_new (totype, expr);
5368 /* Remember that this was list-initialization. */
5369 if (convs->check_narrowing)
5370 TARGET_EXPR_LIST_INIT_P (expr) = true;
5376 expr = mark_rvalue_use (expr);
5377 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
5379 int nelts = CONSTRUCTOR_NELTS (expr);
5381 expr = build_value_init (totype, tf_warning_or_error);
5382 else if (nelts == 1)
5383 expr = CONSTRUCTOR_ELT (expr, 0)->value;
5388 if (type_unknown_p (expr))
5389 expr = instantiate_type (totype, expr, complain);
5390 /* Convert a constant to its underlying value, unless we are
5391 about to bind it to a reference, in which case we need to
5392 leave it as an lvalue. */
5395 expr = decl_constant_value (expr);
5396 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
5397 /* If __null has been converted to an integer type, we do not
5398 want to warn about uses of EXPR as an integer, rather than
5400 expr = build_int_cst (totype, 0);
5404 if (complain & tf_error)
5406 /* Call build_user_type_conversion again for the error. */
5407 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL);
5409 error (" initializing argument %P of %q+D", argnum, fn);
5411 return error_mark_node;
5415 /* Conversion to std::initializer_list<T>. */
5416 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
5417 tree new_ctor = build_constructor (init_list_type_node, NULL);
5418 unsigned len = CONSTRUCTOR_NELTS (expr);
5420 VEC(tree,gc) *parms;
5423 /* Convert all the elements. */
5424 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
5426 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
5427 1, false, false, complain);
5428 if (sub == error_mark_node)
5430 if (!BRACE_ENCLOSED_INITIALIZER_P (val))
5431 check_narrowing (TREE_TYPE (sub), val);
5432 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
5434 /* Build up the array. */
5435 elttype = cp_build_qualified_type
5436 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
5437 array = build_array_of_n_type (elttype, len);
5438 array = finish_compound_literal (array, new_ctor);
5440 parms = make_tree_vector ();
5441 VEC_safe_push (tree, gc, parms, decay_conversion (array));
5442 VEC_safe_push (tree, gc, parms, size_int (len));
5443 /* Call the private constructor. */
5444 push_deferring_access_checks (dk_no_check);
5445 new_ctor = build_special_member_call
5446 (NULL_TREE, complete_ctor_identifier, &parms, totype, 0, complain);
5447 release_tree_vector (parms);
5448 pop_deferring_access_checks ();
5449 return build_cplus_new (totype, new_ctor);
5453 return get_target_expr (digest_init (totype, expr));
5459 expr = convert_like_real (convs->u.next, expr, fn, argnum,
5460 convs->kind == ck_ref_bind ? -1 : 1,
5461 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
5464 if (expr == error_mark_node)
5465 return error_mark_node;
5467 switch (convs->kind)
5470 expr = decay_conversion (expr);
5471 if (! MAYBE_CLASS_TYPE_P (totype))
5473 /* Else fall through. */
5475 if (convs->kind == ck_base && !convs->need_temporary_p)
5477 /* We are going to bind a reference directly to a base-class
5478 subobject of EXPR. */
5479 /* Build an expression for `*((base*) &expr)'. */
5480 expr = cp_build_addr_expr (expr, complain);
5481 expr = convert_to_base (expr, build_pointer_type (totype),
5482 !c_cast_p, /*nonnull=*/true, complain);
5483 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain);
5487 /* Copy-initialization where the cv-unqualified version of the source
5488 type is the same class as, or a derived class of, the class of the
5489 destination [is treated as direct-initialization]. [dcl.init] */
5490 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
5491 if (convs->user_conv_p)
5492 /* This conversion is being done in the context of a user-defined
5493 conversion (i.e. the second step of copy-initialization), so
5494 don't allow any more. */
5495 flags |= LOOKUP_NO_CONVERSION;
5496 if (convs->rvaluedness_matches_p)
5497 flags |= LOOKUP_PREFER_RVALUE;
5498 if (TREE_CODE (expr) == TARGET_EXPR
5499 && TARGET_EXPR_LIST_INIT_P (expr))
5500 /* Copy-list-initialization doesn't actually involve a copy. */
5502 expr = build_temp (expr, totype, flags, &diag_kind, complain);
5503 if (diag_kind && fn)
5505 if ((complain & tf_error))
5506 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0,
5507 " initializing argument %P of %qD", argnum, fn);
5508 else if (diag_kind == DK_ERROR)
5509 return error_mark_node;
5511 return build_cplus_new (totype, expr);
5515 tree ref_type = totype;
5517 if (convs->bad_p && TYPE_REF_IS_RVALUE (ref_type)
5518 && real_lvalue_p (expr))
5520 if (complain & tf_error)
5522 error ("cannot bind %qT lvalue to %qT",
5523 TREE_TYPE (expr), totype);
5525 error (" initializing argument %P of %q+D", argnum, fn);
5527 return error_mark_node;
5530 /* If necessary, create a temporary.
5532 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5533 that need temporaries, even when their types are reference
5534 compatible with the type of reference being bound, so the
5535 upcoming call to cp_build_addr_expr doesn't fail. */
5536 if (convs->need_temporary_p
5537 || TREE_CODE (expr) == CONSTRUCTOR
5538 || TREE_CODE (expr) == VA_ARG_EXPR)
5540 /* Otherwise, a temporary of type "cv1 T1" is created and
5541 initialized from the initializer expression using the rules
5542 for a non-reference copy-initialization (8.5). */
5544 tree type = TREE_TYPE (ref_type);
5545 cp_lvalue_kind lvalue = real_lvalue_p (expr);
5547 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5548 (type, convs->u.next->type));
5549 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
5550 && !TYPE_REF_IS_RVALUE (ref_type))
5552 if (complain & tf_error)
5554 /* If the reference is volatile or non-const, we
5555 cannot create a temporary. */
5556 if (lvalue & clk_bitfield)
5557 error ("cannot bind bitfield %qE to %qT",
5559 else if (lvalue & clk_packed)
5560 error ("cannot bind packed field %qE to %qT",
5563 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
5565 return error_mark_node;
5567 /* If the source is a packed field, and we must use a copy
5568 constructor, then building the target expr will require
5569 binding the field to the reference parameter to the
5570 copy constructor, and we'll end up with an infinite
5571 loop. If we can use a bitwise copy, then we'll be
5573 if ((lvalue & clk_packed)
5574 && CLASS_TYPE_P (type)
5575 && type_has_nontrivial_copy_init (type))
5577 if (complain & tf_error)
5578 error ("cannot bind packed field %qE to %qT",
5580 return error_mark_node;
5582 if (lvalue & clk_bitfield)
5584 expr = convert_bitfield_to_declared_type (expr);
5585 expr = fold_convert (type, expr);
5587 expr = build_target_expr_with_type (expr, type);
5590 /* Take the address of the thing to which we will bind the
5592 expr = cp_build_addr_expr (expr, complain);
5593 if (expr == error_mark_node)
5594 return error_mark_node;
5596 /* Convert it to a pointer to the type referred to by the
5597 reference. This will adjust the pointer if a derived to
5598 base conversion is being performed. */
5599 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
5601 /* Convert the pointer to the desired reference type. */
5602 return build_nop (ref_type, expr);
5606 return decay_conversion (expr);
5609 /* Warn about deprecated conversion if appropriate. */
5610 string_conv_p (totype, expr, 1);
5615 expr = convert_to_base (expr, totype, !c_cast_p,
5616 /*nonnull=*/false, complain);
5617 return build_nop (totype, expr);
5620 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
5621 c_cast_p, complain);
5627 if (convs->check_narrowing)
5628 check_narrowing (totype, expr);
5630 if (issue_conversion_warnings && (complain & tf_warning))
5631 expr = convert_and_check (totype, expr);
5633 expr = convert (totype, expr);
5638 /* ARG is being passed to a varargs function. Perform any conversions
5639 required. Return the converted value. */
5642 convert_arg_to_ellipsis (tree arg)
5648 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5649 standard conversions are performed. */
5650 arg = decay_conversion (arg);
5651 arg_type = TREE_TYPE (arg);
5654 If the argument has integral or enumeration type that is subject
5655 to the integral promotions (_conv.prom_), or a floating point
5656 type that is subject to the floating point promotion
5657 (_conv.fpprom_), the value of the argument is converted to the
5658 promoted type before the call. */
5659 if (TREE_CODE (arg_type) == REAL_TYPE
5660 && (TYPE_PRECISION (arg_type)
5661 < TYPE_PRECISION (double_type_node))
5662 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
5664 if (warn_double_promotion && !c_inhibit_evaluation_warnings)
5665 warning (OPT_Wdouble_promotion,
5666 "implicit conversion from %qT to %qT when passing "
5667 "argument to function",
5668 arg_type, double_type_node);
5669 arg = convert_to_real (double_type_node, arg);
5671 else if (NULLPTR_TYPE_P (arg_type))
5672 arg = null_pointer_node;
5673 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
5674 arg = perform_integral_promotions (arg);
5676 arg = require_complete_type (arg);
5677 arg_type = TREE_TYPE (arg);
5679 if (arg != error_mark_node
5680 /* In a template (or ill-formed code), we can have an incomplete type
5681 even after require_complete_type, in which case we don't know
5682 whether it has trivial copy or not. */
5683 && COMPLETE_TYPE_P (arg_type)
5684 && (type_has_nontrivial_copy_init (arg_type)
5685 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
5687 /* [expr.call] 5.2.2/7:
5688 Passing a potentially-evaluated argument of class type (Clause 9)
5689 with a non-trivial copy constructor or a non-trivial destructor
5690 with no corresponding parameter is conditionally-supported, with
5691 implementation-defined semantics.
5693 We used to just warn here and do a bitwise copy, but now
5694 cp_expr_size will abort if we try to do that.
5696 If the call appears in the context of a sizeof expression,
5697 it is not potentially-evaluated. */
5698 if (cp_unevaluated_operand == 0)
5699 error ("cannot pass objects of non-trivially-copyable "
5700 "type %q#T through %<...%>", arg_type);
5706 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5709 build_x_va_arg (tree expr, tree type)
5711 if (processing_template_decl)
5712 return build_min (VA_ARG_EXPR, type, expr);
5714 type = complete_type_or_else (type, NULL_TREE);
5716 if (expr == error_mark_node || !type)
5717 return error_mark_node;
5719 expr = mark_lvalue_use (expr);
5721 if (type_has_nontrivial_copy_init (type)
5722 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
5723 || TREE_CODE (type) == REFERENCE_TYPE)
5725 /* Remove reference types so we don't ICE later on. */
5726 tree type1 = non_reference (type);
5727 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5728 error ("cannot receive objects of non-trivially-copyable type %q#T "
5729 "through %<...%>; ", type);
5730 expr = convert (build_pointer_type (type1), null_node);
5731 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error);
5735 return build_va_arg (input_location, expr, type);
5738 /* TYPE has been given to va_arg. Apply the default conversions which
5739 would have happened when passed via ellipsis. Return the promoted
5740 type, or the passed type if there is no change. */
5743 cxx_type_promotes_to (tree type)
5747 /* Perform the array-to-pointer and function-to-pointer
5749 type = type_decays_to (type);
5751 promote = type_promotes_to (type);
5752 if (same_type_p (type, promote))
5758 /* ARG is a default argument expression being passed to a parameter of
5759 the indicated TYPE, which is a parameter to FN. PARMNUM is the
5760 zero-based argument number. Do any required conversions. Return
5761 the converted value. */
5763 static GTY(()) VEC(tree,gc) *default_arg_context;
5765 push_defarg_context (tree fn)
5766 { VEC_safe_push (tree, gc, default_arg_context, fn); }
5768 pop_defarg_context (void)
5769 { VEC_pop (tree, default_arg_context); }
5772 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
5777 /* See through clones. */
5778 fn = DECL_ORIGIN (fn);
5780 /* Detect recursion. */
5781 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t)
5784 error ("recursive evaluation of default argument for %q#D", fn);
5785 return error_mark_node;
5788 /* If the ARG is an unparsed default argument expression, the
5789 conversion cannot be performed. */
5790 if (TREE_CODE (arg) == DEFAULT_ARG)
5792 error ("call to %qD uses the default argument for parameter %P, which "
5793 "is not yet defined", fn, parmnum);
5794 return error_mark_node;
5797 push_defarg_context (fn);
5799 if (fn && DECL_TEMPLATE_INFO (fn))
5800 arg = tsubst_default_argument (fn, type, arg);
5806 The names in the expression are bound, and the semantic
5807 constraints are checked, at the point where the default
5808 expressions appears.
5810 we must not perform access checks here. */
5811 push_deferring_access_checks (dk_no_check);
5812 arg = break_out_target_exprs (arg);
5813 if (TREE_CODE (arg) == CONSTRUCTOR)
5815 arg = digest_init (type, arg);
5816 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5817 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5818 tf_warning_or_error);
5822 /* We must make a copy of ARG, in case subsequent processing
5823 alters any part of it. For example, during gimplification a
5824 cast of the form (T) &X::f (where "f" is a member function)
5825 will lead to replacing the PTRMEM_CST for &X::f with a
5826 VAR_DECL. We can avoid the copy for constants, since they
5827 are never modified in place. */
5828 if (!CONSTANT_CLASS_P (arg))
5829 arg = unshare_expr (arg);
5830 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5831 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5832 tf_warning_or_error);
5833 arg = convert_for_arg_passing (type, arg);
5835 pop_deferring_access_checks();
5837 pop_defarg_context ();
5842 /* Returns the type which will really be used for passing an argument of
5846 type_passed_as (tree type)
5848 /* Pass classes with copy ctors by invisible reference. */
5849 if (TREE_ADDRESSABLE (type))
5851 type = build_reference_type (type);
5852 /* There are no other pointers to this temporary. */
5853 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
5855 else if (targetm.calls.promote_prototypes (type)
5856 && INTEGRAL_TYPE_P (type)
5857 && COMPLETE_TYPE_P (type)
5858 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5859 TYPE_SIZE (integer_type_node)))
5860 type = integer_type_node;
5865 /* Actually perform the appropriate conversion. */
5868 convert_for_arg_passing (tree type, tree val)
5872 /* If VAL is a bitfield, then -- since it has already been converted
5873 to TYPE -- it cannot have a precision greater than TYPE.
5875 If it has a smaller precision, we must widen it here. For
5876 example, passing "int f:3;" to a function expecting an "int" will
5877 not result in any conversion before this point.
5879 If the precision is the same we must not risk widening. For
5880 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5881 often have type "int", even though the C++ type for the field is
5882 "long long". If the value is being passed to a function
5883 expecting an "int", then no conversions will be required. But,
5884 if we call convert_bitfield_to_declared_type, the bitfield will
5885 be converted to "long long". */
5886 bitfield_type = is_bitfield_expr_with_lowered_type (val);
5888 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
5889 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
5891 if (val == error_mark_node)
5893 /* Pass classes with copy ctors by invisible reference. */
5894 else if (TREE_ADDRESSABLE (type))
5895 val = build1 (ADDR_EXPR, build_reference_type (type), val);
5896 else if (targetm.calls.promote_prototypes (type)
5897 && INTEGRAL_TYPE_P (type)
5898 && COMPLETE_TYPE_P (type)
5899 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5900 TYPE_SIZE (integer_type_node)))
5901 val = perform_integral_promotions (val);
5902 if (warn_missing_format_attribute)
5904 tree rhstype = TREE_TYPE (val);
5905 const enum tree_code coder = TREE_CODE (rhstype);
5906 const enum tree_code codel = TREE_CODE (type);
5907 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5909 && check_missing_format_attribute (type, rhstype))
5910 warning (OPT_Wmissing_format_attribute,
5911 "argument of function call might be a candidate for a format attribute");
5916 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5917 which no conversions at all should be done. This is true for some
5918 builtins which don't act like normal functions. */
5921 magic_varargs_p (tree fn)
5923 if (DECL_BUILT_IN (fn))
5924 switch (DECL_FUNCTION_CODE (fn))
5926 case BUILT_IN_CLASSIFY_TYPE:
5927 case BUILT_IN_CONSTANT_P:
5928 case BUILT_IN_NEXT_ARG:
5929 case BUILT_IN_VA_START:
5933 return lookup_attribute ("type generic",
5934 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
5940 /* Subroutine of the various build_*_call functions. Overload resolution
5941 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5942 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5943 bitmask of various LOOKUP_* flags which apply to the call itself. */
5946 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
5949 const VEC(tree,gc) *args = cand->args;
5950 tree first_arg = cand->first_arg;
5951 conversion **convs = cand->convs;
5953 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
5958 unsigned int arg_index = 0;
5962 bool already_used = false;
5964 /* In a template, there is no need to perform all of the work that
5965 is normally done. We are only interested in the type of the call
5966 expression, i.e., the return type of the function. Any semantic
5967 errors will be deferred until the template is instantiated. */
5968 if (processing_template_decl)
5972 const tree *argarray;
5975 return_type = TREE_TYPE (TREE_TYPE (fn));
5976 nargs = VEC_length (tree, args);
5977 if (first_arg == NULL_TREE)
5978 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args));
5986 alcarray = XALLOCAVEC (tree, nargs);
5987 alcarray[0] = first_arg;
5988 FOR_EACH_VEC_ELT (tree, args, ix, arg)
5989 alcarray[ix + 1] = arg;
5990 argarray = alcarray;
5992 expr = build_call_array_loc (input_location,
5993 return_type, build_addr_func (fn), nargs,
5995 if (TREE_THIS_VOLATILE (fn) && cfun)
5996 current_function_returns_abnormally = 1;
5997 return convert_from_reference (expr);
6000 /* Give any warnings we noticed during overload resolution. */
6001 if (cand->warnings && (complain & tf_warning))
6003 struct candidate_warning *w;
6004 for (w = cand->warnings; w; w = w->next)
6005 joust (cand, w->loser, 1);
6008 /* Make =delete work with SFINAE. */
6009 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
6010 return error_mark_node;
6012 if (DECL_FUNCTION_MEMBER_P (fn))
6015 /* If FN is a template function, two cases must be considered.
6020 template <class T> void f();
6022 template <class T> struct B {
6026 struct C : A, B<int> {
6028 using B<int>::g; // #2
6031 In case #1 where `A::f' is a member template, DECL_ACCESS is
6032 recorded in the primary template but not in its specialization.
6033 We check access of FN using its primary template.
6035 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
6036 because it is a member of class template B, DECL_ACCESS is
6037 recorded in the specialization `B<int>::g'. We cannot use its
6038 primary template because `B<T>::g' and `B<int>::g' may have
6039 different access. */
6040 if (DECL_TEMPLATE_INFO (fn)
6041 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
6042 access_fn = DECL_TI_TEMPLATE (fn);
6045 if (flags & LOOKUP_SPECULATIVE)
6047 if (!speculative_access_check (cand->access_path, access_fn, fn,
6048 !!(flags & LOOKUP_COMPLAIN)))
6049 return error_mark_node;
6052 perform_or_defer_access_check (cand->access_path, access_fn, fn);
6055 /* If we're checking for implicit delete, don't bother with argument
6057 if (flags & LOOKUP_SPECULATIVE)
6059 if (DECL_DELETED_FN (fn))
6061 if (flags & LOOKUP_COMPLAIN)
6063 return error_mark_node;
6065 if (cand->viable == 1)
6067 else if (!(flags & LOOKUP_COMPLAIN))
6068 /* Reject bad conversions now. */
6069 return error_mark_node;
6070 /* else continue to get conversion error. */
6073 /* Find maximum size of vector to hold converted arguments. */
6074 parmlen = list_length (parm);
6075 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0);
6076 if (parmlen > nargs)
6078 argarray = XALLOCAVEC (tree, nargs);
6080 /* The implicit parameters to a constructor are not considered by overload
6081 resolution, and must be of the proper type. */
6082 if (DECL_CONSTRUCTOR_P (fn))
6084 if (first_arg != NULL_TREE)
6086 argarray[j++] = first_arg;
6087 first_arg = NULL_TREE;
6091 argarray[j++] = VEC_index (tree, args, arg_index);
6094 parm = TREE_CHAIN (parm);
6095 /* We should never try to call the abstract constructor. */
6096 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
6098 if (DECL_HAS_VTT_PARM_P (fn))
6100 argarray[j++] = VEC_index (tree, args, arg_index);
6102 parm = TREE_CHAIN (parm);
6105 /* Bypass access control for 'this' parameter. */
6106 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6108 tree parmtype = TREE_VALUE (parm);
6109 tree arg = (first_arg != NULL_TREE
6111 : VEC_index (tree, args, arg_index));
6112 tree argtype = TREE_TYPE (arg);
6116 if (convs[i]->bad_p)
6118 if (complain & tf_error)
6119 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
6120 TREE_TYPE (argtype), fn);
6122 return error_mark_node;
6125 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
6126 X is called for an object that is not of type X, or of a type
6127 derived from X, the behavior is undefined.
6129 So we can assume that anything passed as 'this' is non-null, and
6130 optimize accordingly. */
6131 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
6132 /* Convert to the base in which the function was declared. */
6133 gcc_assert (cand->conversion_path != NULL_TREE);
6134 converted_arg = build_base_path (PLUS_EXPR,
6136 cand->conversion_path,
6138 /* Check that the base class is accessible. */
6139 if (!accessible_base_p (TREE_TYPE (argtype),
6140 BINFO_TYPE (cand->conversion_path), true))
6141 error ("%qT is not an accessible base of %qT",
6142 BINFO_TYPE (cand->conversion_path),
6143 TREE_TYPE (argtype));
6144 /* If fn was found by a using declaration, the conversion path
6145 will be to the derived class, not the base declaring fn. We
6146 must convert from derived to base. */
6147 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
6148 TREE_TYPE (parmtype), ba_unique, NULL);
6149 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
6152 argarray[j++] = converted_arg;
6153 parm = TREE_CHAIN (parm);
6154 if (first_arg != NULL_TREE)
6155 first_arg = NULL_TREE;
6162 gcc_assert (first_arg == NULL_TREE);
6163 for (; arg_index < VEC_length (tree, args) && parm;
6164 parm = TREE_CHAIN (parm), ++arg_index, ++i)
6166 tree type = TREE_VALUE (parm);
6167 tree arg = VEC_index (tree, args, arg_index);
6171 /* Don't make a copy here if build_call is going to. */
6172 if (conv->kind == ck_rvalue
6173 && COMPLETE_TYPE_P (complete_type (type))
6174 && !TREE_ADDRESSABLE (type))
6175 conv = conv->u.next;
6177 /* Warn about initializer_list deduction that isn't currently in the
6179 if (cxx_dialect > cxx98
6180 && flag_deduce_init_list
6181 && cand->template_decl
6182 && is_std_init_list (non_reference (type))
6183 && BRACE_ENCLOSED_INITIALIZER_P (arg))
6185 tree tmpl = TI_TEMPLATE (cand->template_decl);
6186 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
6187 tree patparm = get_pattern_parm (realparm, tmpl);
6188 tree pattype = TREE_TYPE (patparm);
6189 if (PACK_EXPANSION_P (pattype))
6190 pattype = PACK_EXPANSION_PATTERN (pattype);
6191 pattype = non_reference (pattype);
6193 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
6194 && (cand->explicit_targs == NULL_TREE
6195 || (TREE_VEC_LENGTH (cand->explicit_targs)
6196 <= TEMPLATE_TYPE_IDX (pattype))))
6198 pedwarn (input_location, 0, "deducing %qT as %qT",
6199 non_reference (TREE_TYPE (patparm)),
6200 non_reference (type));
6201 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
6202 pedwarn (input_location, 0,
6203 " (you can disable this with -fno-deduce-init-list)");
6207 val = convert_like_with_context (conv, arg, fn, i-is_method, complain);
6209 val = convert_for_arg_passing (type, val);
6210 if (val == error_mark_node)
6211 return error_mark_node;
6213 argarray[j++] = val;
6216 /* Default arguments */
6217 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
6218 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
6219 TREE_PURPOSE (parm),
6222 for (; arg_index < VEC_length (tree, args); ++arg_index)
6224 tree a = VEC_index (tree, args, arg_index);
6225 if (magic_varargs_p (fn))
6226 /* Do no conversions for magic varargs. */
6227 a = mark_type_use (a);
6229 a = convert_arg_to_ellipsis (a);
6233 gcc_assert (j <= nargs);
6236 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
6237 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
6239 /* Avoid actually calling copy constructors and copy assignment operators,
6242 if (! flag_elide_constructors)
6243 /* Do things the hard way. */;
6244 else if (cand->num_convs == 1
6245 && (DECL_COPY_CONSTRUCTOR_P (fn)
6246 || DECL_MOVE_CONSTRUCTOR_P (fn)))
6249 tree arg = argarray[num_artificial_parms_for (fn)];
6251 bool trivial = trivial_fn_p (fn);
6253 /* Pull out the real argument, disregarding const-correctness. */
6255 while (CONVERT_EXPR_P (targ)
6256 || TREE_CODE (targ) == NON_LVALUE_EXPR)
6257 targ = TREE_OPERAND (targ, 0);
6258 if (TREE_CODE (targ) == ADDR_EXPR)
6260 targ = TREE_OPERAND (targ, 0);
6261 if (!same_type_ignoring_top_level_qualifiers_p
6262 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
6271 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6273 /* [class.copy]: the copy constructor is implicitly defined even if
6274 the implementation elided its use. */
6275 if (!trivial || DECL_DELETED_FN (fn))
6278 already_used = true;
6281 /* If we're creating a temp and we already have one, don't create a
6282 new one. If we're not creating a temp but we get one, use
6283 INIT_EXPR to collapse the temp into our target. Otherwise, if the
6284 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
6285 temp or an INIT_EXPR otherwise. */
6287 if (integer_zerop (fa))
6289 if (TREE_CODE (arg) == TARGET_EXPR)
6292 return force_target_expr (DECL_CONTEXT (fn), arg);
6294 else if (TREE_CODE (arg) == TARGET_EXPR || trivial)
6296 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL,
6299 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
6303 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
6304 && trivial_fn_p (fn)
6305 && !DECL_DELETED_FN (fn))
6307 tree to = stabilize_reference
6308 (cp_build_indirect_ref (argarray[0], RO_NULL, complain));
6309 tree type = TREE_TYPE (to);
6310 tree as_base = CLASSTYPE_AS_BASE (type);
6311 tree arg = argarray[1];
6313 if (is_really_empty_class (type))
6315 /* Avoid copying empty classes. */
6316 val = build2 (COMPOUND_EXPR, void_type_node, to, arg);
6317 TREE_NO_WARNING (val) = 1;
6318 val = build2 (COMPOUND_EXPR, type, val, to);
6319 TREE_NO_WARNING (val) = 1;
6321 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
6323 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6324 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
6328 /* We must only copy the non-tail padding parts.
6329 Use __builtin_memcpy for the bitwise copy.
6330 FIXME fix 22488 so we can go back to using MODIFY_EXPR
6331 instead of an explicit call to memcpy. */
6333 tree arg0, arg1, arg2, t;
6334 tree test = NULL_TREE;
6336 arg2 = TYPE_SIZE_UNIT (as_base);
6338 arg0 = cp_build_addr_expr (to, complain);
6340 if (!can_trust_pointer_alignment ())
6342 /* If we can't be sure about pointer alignment, a call
6343 to __builtin_memcpy is expanded as a call to memcpy, which
6344 is invalid with identical args. Otherwise it is
6345 expanded as a block move, which should be safe. */
6346 arg0 = save_expr (arg0);
6347 arg1 = save_expr (arg1);
6348 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
6350 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
6351 t = build_call_n (t, 3, arg0, arg1, arg2);
6353 t = convert (TREE_TYPE (arg0), t);
6355 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
6356 val = cp_build_indirect_ref (t, RO_NULL, complain);
6357 TREE_NO_WARNING (val) = 1;
6362 /* FIXME handle trivial default constructor and destructor, too. */
6367 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
6370 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
6373 gcc_assert (binfo && binfo != error_mark_node);
6375 /* Warn about deprecated virtual functions now, since we're about
6376 to throw away the decl. */
6377 if (TREE_DEPRECATED (fn))
6378 warn_deprecated_use (fn, NULL_TREE);
6380 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
6381 if (TREE_SIDE_EFFECTS (argarray[0]))
6382 argarray[0] = save_expr (argarray[0]);
6383 t = build_pointer_type (TREE_TYPE (fn));
6384 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
6385 fn = build_java_interface_fn_ref (fn, argarray[0]);
6387 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
6391 fn = build_addr_func (fn);
6393 return build_cxx_call (fn, nargs, argarray);
6396 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
6397 This function performs no overload resolution, conversion, or other
6398 high-level operations. */
6401 build_cxx_call (tree fn, int nargs, tree *argarray)
6405 fn = build_call_a (fn, nargs, argarray);
6407 /* If this call might throw an exception, note that fact. */
6408 fndecl = get_callee_fndecl (fn);
6409 if ((!fndecl || !TREE_NOTHROW (fndecl))
6410 && at_function_scope_p ()
6412 && cp_function_chain)
6413 cp_function_chain->can_throw = 1;
6415 /* Check that arguments to builtin functions match the expectations. */
6417 && DECL_BUILT_IN (fndecl)
6418 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6419 && !check_builtin_function_arguments (fndecl, nargs, argarray))
6420 return error_mark_node;
6422 /* Some built-in function calls will be evaluated at compile-time in
6424 fn = fold_if_not_in_template (fn);
6426 if (VOID_TYPE_P (TREE_TYPE (fn)))
6429 fn = require_complete_type (fn);
6430 if (fn == error_mark_node)
6431 return error_mark_node;
6433 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
6434 fn = build_cplus_new (TREE_TYPE (fn), fn);
6435 return convert_from_reference (fn);
6438 static GTY(()) tree java_iface_lookup_fn;
6440 /* Make an expression which yields the address of the Java interface
6441 method FN. This is achieved by generating a call to libjava's
6442 _Jv_LookupInterfaceMethodIdx(). */
6445 build_java_interface_fn_ref (tree fn, tree instance)
6447 tree lookup_fn, method, idx;
6448 tree klass_ref, iface, iface_ref;
6451 if (!java_iface_lookup_fn)
6453 tree ftype = build_function_type_list (ptr_type_node,
6454 ptr_type_node, ptr_type_node,
6455 java_int_type_node, NULL_TREE);
6456 java_iface_lookup_fn
6457 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype,
6458 0, NOT_BUILT_IN, NULL, NULL_TREE);
6461 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
6462 This is the first entry in the vtable. */
6463 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL,
6464 tf_warning_or_error),
6467 /* Get the java.lang.Class pointer for the interface being called. */
6468 iface = DECL_CONTEXT (fn);
6469 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
6470 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
6471 || DECL_CONTEXT (iface_ref) != iface)
6473 error ("could not find class$ field in java interface type %qT",
6475 return error_mark_node;
6477 iface_ref = build_address (iface_ref);
6478 iface_ref = convert (build_pointer_type (iface), iface_ref);
6480 /* Determine the itable index of FN. */
6482 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method))
6484 if (!DECL_VIRTUAL_P (method))
6490 idx = build_int_cst (NULL_TREE, i);
6492 lookup_fn = build1 (ADDR_EXPR,
6493 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
6494 java_iface_lookup_fn);
6495 return build_call_nary (ptr_type_node, lookup_fn,
6496 3, klass_ref, iface_ref, idx);
6499 /* Returns the value to use for the in-charge parameter when making a
6500 call to a function with the indicated NAME.
6502 FIXME:Can't we find a neater way to do this mapping? */
6505 in_charge_arg_for_name (tree name)
6507 if (name == base_ctor_identifier
6508 || name == base_dtor_identifier)
6509 return integer_zero_node;
6510 else if (name == complete_ctor_identifier)
6511 return integer_one_node;
6512 else if (name == complete_dtor_identifier)
6513 return integer_two_node;
6514 else if (name == deleting_dtor_identifier)
6515 return integer_three_node;
6517 /* This function should only be called with one of the names listed
6523 /* Build a call to a constructor, destructor, or an assignment
6524 operator for INSTANCE, an expression with class type. NAME
6525 indicates the special member function to call; *ARGS are the
6526 arguments. ARGS may be NULL. This may change ARGS. BINFO
6527 indicates the base of INSTANCE that is to be passed as the `this'
6528 parameter to the member function called.
6530 FLAGS are the LOOKUP_* flags to use when processing the call.
6532 If NAME indicates a complete object constructor, INSTANCE may be
6533 NULL_TREE. In this case, the caller will call build_cplus_new to
6534 store the newly constructed object into a VAR_DECL. */
6537 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args,
6538 tree binfo, int flags, tsubst_flags_t complain)
6541 /* The type of the subobject to be constructed or destroyed. */
6543 VEC(tree,gc) *allocated = NULL;
6546 gcc_assert (name == complete_ctor_identifier
6547 || name == base_ctor_identifier
6548 || name == complete_dtor_identifier
6549 || name == base_dtor_identifier
6550 || name == deleting_dtor_identifier
6551 || name == ansi_assopname (NOP_EXPR));
6554 /* Resolve the name. */
6555 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
6556 return error_mark_node;
6558 binfo = TYPE_BINFO (binfo);
6561 gcc_assert (binfo != NULL_TREE);
6563 class_type = BINFO_TYPE (binfo);
6565 /* Handle the special case where INSTANCE is NULL_TREE. */
6566 if (name == complete_ctor_identifier && !instance)
6568 instance = build_int_cst (build_pointer_type (class_type), 0);
6569 instance = build1 (INDIRECT_REF, class_type, instance);
6573 if (name == complete_dtor_identifier
6574 || name == base_dtor_identifier
6575 || name == deleting_dtor_identifier)
6576 gcc_assert (args == NULL || VEC_empty (tree, *args));
6578 /* Convert to the base class, if necessary. */
6579 if (!same_type_ignoring_top_level_qualifiers_p
6580 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
6582 if (name != ansi_assopname (NOP_EXPR))
6583 /* For constructors and destructors, either the base is
6584 non-virtual, or it is virtual but we are doing the
6585 conversion from a constructor or destructor for the
6586 complete object. In either case, we can convert
6588 instance = convert_to_base_statically (instance, binfo);
6590 /* However, for assignment operators, we must convert
6591 dynamically if the base is virtual. */
6592 instance = build_base_path (PLUS_EXPR, instance,
6593 binfo, /*nonnull=*/1);
6597 gcc_assert (instance != NULL_TREE);
6599 fns = lookup_fnfields (binfo, name, 1);
6601 /* When making a call to a constructor or destructor for a subobject
6602 that uses virtual base classes, pass down a pointer to a VTT for
6604 if ((name == base_ctor_identifier
6605 || name == base_dtor_identifier)
6606 && CLASSTYPE_VBASECLASSES (class_type))
6611 /* If the current function is a complete object constructor
6612 or destructor, then we fetch the VTT directly.
6613 Otherwise, we look it up using the VTT we were given. */
6614 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
6615 vtt = decay_conversion (vtt);
6616 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
6617 build2 (EQ_EXPR, boolean_type_node,
6618 current_in_charge_parm, integer_zero_node),
6621 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
6622 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
6623 BINFO_SUBVTT_INDEX (binfo));
6627 allocated = make_tree_vector ();
6631 VEC_safe_insert (tree, gc, *args, 0, sub_vtt);
6634 ret = build_new_method_call (instance, fns, args,
6635 TYPE_BINFO (BINFO_TYPE (binfo)),
6639 if (allocated != NULL)
6640 release_tree_vector (allocated);
6645 /* Return the NAME, as a C string. The NAME indicates a function that
6646 is a member of TYPE. *FREE_P is set to true if the caller must
6647 free the memory returned.
6649 Rather than go through all of this, we should simply set the names
6650 of constructors and destructors appropriately, and dispense with
6651 ctor_identifier, dtor_identifier, etc. */
6654 name_as_c_string (tree name, tree type, bool *free_p)
6658 /* Assume that we will not allocate memory. */
6660 /* Constructors and destructors are special. */
6661 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6664 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))));
6665 /* For a destructor, add the '~'. */
6666 if (name == complete_dtor_identifier
6667 || name == base_dtor_identifier
6668 || name == deleting_dtor_identifier)
6670 pretty_name = concat ("~", pretty_name, NULL);
6671 /* Remember that we need to free the memory allocated. */
6675 else if (IDENTIFIER_TYPENAME_P (name))
6677 pretty_name = concat ("operator ",
6678 type_as_string_translate (TREE_TYPE (name),
6679 TFF_PLAIN_IDENTIFIER),
6681 /* Remember that we need to free the memory allocated. */
6685 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name)));
6690 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6691 be set, upon return, to the function called. ARGS may be NULL.
6692 This may change ARGS. */
6695 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args,
6696 tree conversion_path, int flags,
6697 tree *fn_p, tsubst_flags_t complain)
6699 struct z_candidate *candidates = 0, *cand;
6700 tree explicit_targs = NULL_TREE;
6701 tree basetype = NULL_TREE;
6704 tree first_mem_arg = NULL_TREE;
6707 bool skip_first_for_error;
6708 VEC(tree,gc) *user_args;
6711 int template_only = 0;
6715 VEC(tree,gc) *orig_args = NULL;
6718 gcc_assert (instance != NULL_TREE);
6720 /* We don't know what function we're going to call, yet. */
6724 if (error_operand_p (instance)
6725 || !fns || error_operand_p (fns))
6726 return error_mark_node;
6728 if (!BASELINK_P (fns))
6730 if (complain & tf_error)
6731 error ("call to non-function %qD", fns);
6732 return error_mark_node;
6735 orig_instance = instance;
6738 /* Dismantle the baselink to collect all the information we need. */
6739 if (!conversion_path)
6740 conversion_path = BASELINK_BINFO (fns);
6741 access_binfo = BASELINK_ACCESS_BINFO (fns);
6742 optype = BASELINK_OPTYPE (fns);
6743 fns = BASELINK_FUNCTIONS (fns);
6744 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
6746 explicit_targs = TREE_OPERAND (fns, 1);
6747 fns = TREE_OPERAND (fns, 0);
6750 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
6751 || TREE_CODE (fns) == TEMPLATE_DECL
6752 || TREE_CODE (fns) == OVERLOAD);
6753 fn = get_first_fn (fns);
6754 name = DECL_NAME (fn);
6756 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
6757 gcc_assert (CLASS_TYPE_P (basetype));
6759 if (processing_template_decl)
6761 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
6762 instance = build_non_dependent_expr (instance);
6764 make_args_non_dependent (*args);
6767 user_args = args == NULL ? NULL : *args;
6768 /* Under DR 147 A::A() is an invalid constructor call,
6769 not a functional cast. */
6770 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
6772 if (! (complain & tf_error))
6773 return error_mark_node;
6775 permerror (input_location,
6776 "cannot call constructor %<%T::%D%> directly",
6778 permerror (input_location, " for a function-style cast, remove the "
6779 "redundant %<::%D%>", name);
6780 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
6785 /* Figure out whether to skip the first argument for the error
6786 message we will display to users if an error occurs. We don't
6787 want to display any compiler-generated arguments. The "this"
6788 pointer hasn't been added yet. However, we must remove the VTT
6789 pointer if this is a call to a base-class constructor or
6791 skip_first_for_error = false;
6792 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6794 /* Callers should explicitly indicate whether they want to construct
6795 the complete object or just the part without virtual bases. */
6796 gcc_assert (name != ctor_identifier);
6797 /* Similarly for destructors. */
6798 gcc_assert (name != dtor_identifier);
6799 /* Remove the VTT pointer, if present. */
6800 if ((name == base_ctor_identifier || name == base_dtor_identifier)
6801 && CLASSTYPE_VBASECLASSES (basetype))
6802 skip_first_for_error = true;
6805 /* Process the argument list. */
6806 if (args != NULL && *args != NULL)
6808 *args = resolve_args (*args);
6810 return error_mark_node;
6813 instance_ptr = build_this (instance);
6815 /* It's OK to call destructors and constructors on cv-qualified objects.
6816 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6818 if (DECL_DESTRUCTOR_P (fn)
6819 || DECL_CONSTRUCTOR_P (fn))
6821 tree type = build_pointer_type (basetype);
6822 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
6823 instance_ptr = build_nop (type, instance_ptr);
6825 if (DECL_DESTRUCTOR_P (fn))
6826 name = complete_dtor_identifier;
6828 first_mem_arg = instance_ptr;
6830 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6831 p = conversion_obstack_alloc (0);
6833 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6834 initializer, not T({ }). */
6835 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args)
6836 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0))
6837 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0)))
6839 gcc_assert (VEC_length (tree, *args) == 1
6840 && !(flags & LOOKUP_ONLYCONVERTING));
6842 add_list_candidates (fns, first_mem_arg, VEC_index (tree, *args, 0),
6843 basetype, explicit_targs, template_only,
6844 conversion_path, access_binfo, flags, &candidates);
6848 add_candidates (fns, first_mem_arg, user_args, optype,
6849 explicit_targs, template_only, conversion_path,
6850 access_binfo, flags, &candidates);
6852 any_viable_p = false;
6853 candidates = splice_viable (candidates, pedantic, &any_viable_p);
6857 if (complain & tf_error)
6859 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
6860 cxx_incomplete_type_error (instance_ptr, basetype);
6862 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
6863 basetype, optype, build_tree_list_vec (user_args),
6864 TREE_TYPE (TREE_TYPE (instance_ptr)));
6871 pretty_name = name_as_c_string (name, basetype, &free_p);
6872 arglist = build_tree_list_vec (user_args);
6873 if (skip_first_for_error)
6874 arglist = TREE_CHAIN (arglist);
6875 error ("no matching function for call to %<%T::%s(%A)%#V%>",
6876 basetype, pretty_name, arglist,
6877 TREE_TYPE (TREE_TYPE (instance_ptr)));
6881 print_z_candidates (location_of (name), candidates);
6883 call = error_mark_node;
6887 cand = tourney (candidates);
6894 if (complain & tf_error)
6896 pretty_name = name_as_c_string (name, basetype, &free_p);
6897 arglist = build_tree_list_vec (user_args);
6898 if (skip_first_for_error)
6899 arglist = TREE_CHAIN (arglist);
6900 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
6902 print_z_candidates (location_of (name), candidates);
6906 call = error_mark_node;
6912 if (!(flags & LOOKUP_NONVIRTUAL)
6913 && DECL_PURE_VIRTUAL_P (fn)
6914 && instance == current_class_ref
6915 && (DECL_CONSTRUCTOR_P (current_function_decl)
6916 || DECL_DESTRUCTOR_P (current_function_decl))
6917 && (complain & tf_warning))
6918 /* This is not an error, it is runtime undefined
6920 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
6921 "pure virtual %q#D called from constructor"
6922 : "pure virtual %q#D called from destructor"),
6925 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
6926 && is_dummy_object (instance_ptr))
6928 if (complain & tf_error)
6929 error ("cannot call member function %qD without object",
6931 call = error_mark_node;
6935 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
6936 && resolves_to_fixed_type_p (instance, 0))
6937 flags |= LOOKUP_NONVIRTUAL;
6938 /* Now we know what function is being called. */
6941 /* Build the actual CALL_EXPR. */
6942 call = build_over_call (cand, flags, complain);
6943 /* In an expression of the form `a->f()' where `f' turns
6944 out to be a static member function, `a' is
6945 none-the-less evaluated. */
6946 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
6947 && !is_dummy_object (instance_ptr)
6948 && TREE_SIDE_EFFECTS (instance_ptr))
6949 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
6950 instance_ptr, call);
6951 else if (call != error_mark_node
6952 && DECL_DESTRUCTOR_P (cand->fn)
6953 && !VOID_TYPE_P (TREE_TYPE (call)))
6954 /* An explicit call of the form "x->~X()" has type
6955 "void". However, on platforms where destructors
6956 return "this" (i.e., those where
6957 targetm.cxx.cdtor_returns_this is true), such calls
6958 will appear to have a return value of pointer type
6959 to the low-level call machinery. We do not want to
6960 change the low-level machinery, since we want to be
6961 able to optimize "delete f()" on such platforms as
6962 "operator delete(~X(f()))" (rather than generating
6963 "t = f(), ~X(t), operator delete (t)"). */
6964 call = build_nop (void_type_node, call);
6969 if (processing_template_decl && call != error_mark_node)
6971 bool cast_to_void = false;
6973 if (TREE_CODE (call) == COMPOUND_EXPR)
6974 call = TREE_OPERAND (call, 1);
6975 else if (TREE_CODE (call) == NOP_EXPR)
6977 cast_to_void = true;
6978 call = TREE_OPERAND (call, 0);
6980 if (TREE_CODE (call) == INDIRECT_REF)
6981 call = TREE_OPERAND (call, 0);
6982 call = (build_min_non_dep_call_vec
6984 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
6985 orig_instance, orig_fns, NULL_TREE),
6987 call = convert_from_reference (call);
6989 call = build_nop (void_type_node, call);
6992 /* Free all the conversions we allocated. */
6993 obstack_free (&conversion_obstack, p);
6995 if (orig_args != NULL)
6996 release_tree_vector (orig_args);
7001 /* Returns true iff standard conversion sequence ICS1 is a proper
7002 subsequence of ICS2. */
7005 is_subseq (conversion *ics1, conversion *ics2)
7007 /* We can assume that a conversion of the same code
7008 between the same types indicates a subsequence since we only get
7009 here if the types we are converting from are the same. */
7011 while (ics1->kind == ck_rvalue
7012 || ics1->kind == ck_lvalue)
7013 ics1 = ics1->u.next;
7017 while (ics2->kind == ck_rvalue
7018 || ics2->kind == ck_lvalue)
7019 ics2 = ics2->u.next;
7021 if (ics2->kind == ck_user
7022 || ics2->kind == ck_ambig
7023 || ics2->kind == ck_aggr
7024 || ics2->kind == ck_list
7025 || ics2->kind == ck_identity)
7026 /* At this point, ICS1 cannot be a proper subsequence of
7027 ICS2. We can get a USER_CONV when we are comparing the
7028 second standard conversion sequence of two user conversion
7032 ics2 = ics2->u.next;
7034 if (ics2->kind == ics1->kind
7035 && same_type_p (ics2->type, ics1->type)
7036 && same_type_p (ics2->u.next->type,
7037 ics1->u.next->type))
7042 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
7043 be any _TYPE nodes. */
7046 is_properly_derived_from (tree derived, tree base)
7048 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
7051 /* We only allow proper derivation here. The DERIVED_FROM_P macro
7052 considers every class derived from itself. */
7053 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
7054 && DERIVED_FROM_P (base, derived));
7057 /* We build the ICS for an implicit object parameter as a pointer
7058 conversion sequence. However, such a sequence should be compared
7059 as if it were a reference conversion sequence. If ICS is the
7060 implicit conversion sequence for an implicit object parameter,
7061 modify it accordingly. */
7064 maybe_handle_implicit_object (conversion **ics)
7068 /* [over.match.funcs]
7070 For non-static member functions, the type of the
7071 implicit object parameter is "reference to cv X"
7072 where X is the class of which the function is a
7073 member and cv is the cv-qualification on the member
7074 function declaration. */
7075 conversion *t = *ics;
7076 tree reference_type;
7078 /* The `this' parameter is a pointer to a class type. Make the
7079 implicit conversion talk about a reference to that same class
7081 reference_type = TREE_TYPE (t->type);
7082 reference_type = build_reference_type (reference_type);
7084 if (t->kind == ck_qual)
7086 if (t->kind == ck_ptr)
7088 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
7089 t = direct_reference_binding (reference_type, t);
7091 t->rvaluedness_matches_p = 0;
7096 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
7097 and return the initial reference binding conversion. Otherwise,
7098 leave *ICS unchanged and return NULL. */
7101 maybe_handle_ref_bind (conversion **ics)
7103 if ((*ics)->kind == ck_ref_bind)
7105 conversion *old_ics = *ics;
7106 *ics = old_ics->u.next;
7107 (*ics)->user_conv_p = old_ics->user_conv_p;
7114 /* Compare two implicit conversion sequences according to the rules set out in
7115 [over.ics.rank]. Return values:
7117 1: ics1 is better than ics2
7118 -1: ics2 is better than ics1
7119 0: ics1 and ics2 are indistinguishable */
7122 compare_ics (conversion *ics1, conversion *ics2)
7128 tree deref_from_type1 = NULL_TREE;
7129 tree deref_from_type2 = NULL_TREE;
7130 tree deref_to_type1 = NULL_TREE;
7131 tree deref_to_type2 = NULL_TREE;
7132 conversion_rank rank1, rank2;
7134 /* REF_BINDING is nonzero if the result of the conversion sequence
7135 is a reference type. In that case REF_CONV is the reference
7136 binding conversion. */
7137 conversion *ref_conv1;
7138 conversion *ref_conv2;
7140 /* Handle implicit object parameters. */
7141 maybe_handle_implicit_object (&ics1);
7142 maybe_handle_implicit_object (&ics2);
7144 /* Handle reference parameters. */
7145 ref_conv1 = maybe_handle_ref_bind (&ics1);
7146 ref_conv2 = maybe_handle_ref_bind (&ics2);
7148 /* List-initialization sequence L1 is a better conversion sequence than
7149 list-initialization sequence L2 if L1 converts to
7150 std::initializer_list<X> for some X and L2 does not. */
7151 if (ics1->kind == ck_list && ics2->kind != ck_list)
7153 if (ics2->kind == ck_list && ics1->kind != ck_list)
7158 When comparing the basic forms of implicit conversion sequences (as
7159 defined in _over.best.ics_)
7161 --a standard conversion sequence (_over.ics.scs_) is a better
7162 conversion sequence than a user-defined conversion sequence
7163 or an ellipsis conversion sequence, and
7165 --a user-defined conversion sequence (_over.ics.user_) is a
7166 better conversion sequence than an ellipsis conversion sequence
7167 (_over.ics.ellipsis_). */
7168 rank1 = CONVERSION_RANK (ics1);
7169 rank2 = CONVERSION_RANK (ics2);
7173 else if (rank1 < rank2)
7176 if (rank1 == cr_bad)
7178 /* Both ICS are bad. We try to make a decision based on what would
7179 have happened if they'd been good. This is not an extension,
7180 we'll still give an error when we build up the call; this just
7181 helps us give a more helpful error message. */
7182 rank1 = BAD_CONVERSION_RANK (ics1);
7183 rank2 = BAD_CONVERSION_RANK (ics2);
7187 else if (rank1 < rank2)
7190 /* We couldn't make up our minds; try to figure it out below. */
7193 if (ics1->ellipsis_p)
7194 /* Both conversions are ellipsis conversions. */
7197 /* User-defined conversion sequence U1 is a better conversion sequence
7198 than another user-defined conversion sequence U2 if they contain the
7199 same user-defined conversion operator or constructor and if the sec-
7200 ond standard conversion sequence of U1 is better than the second
7201 standard conversion sequence of U2. */
7203 /* Handle list-conversion with the same code even though it isn't always
7204 ranked as a user-defined conversion and it doesn't have a second
7205 standard conversion sequence; it will still have the desired effect.
7206 Specifically, we need to do the reference binding comparison at the
7207 end of this function. */
7209 if (ics1->user_conv_p || ics1->kind == ck_list)
7214 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
7215 if (t1->kind == ck_ambig || t1->kind == ck_aggr
7216 || t1->kind == ck_list)
7218 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
7219 if (t2->kind == ck_ambig || t2->kind == ck_aggr
7220 || t2->kind == ck_list)
7223 if (t1->kind != t2->kind)
7225 else if (t1->kind == ck_user)
7227 if (t1->cand->fn != t2->cand->fn)
7232 /* For ambiguous or aggregate conversions, use the target type as
7233 a proxy for the conversion function. */
7234 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
7238 /* We can just fall through here, after setting up
7239 FROM_TYPE1 and FROM_TYPE2. */
7240 from_type1 = t1->type;
7241 from_type2 = t2->type;
7248 /* We're dealing with two standard conversion sequences.
7252 Standard conversion sequence S1 is a better conversion
7253 sequence than standard conversion sequence S2 if
7255 --S1 is a proper subsequence of S2 (comparing the conversion
7256 sequences in the canonical form defined by _over.ics.scs_,
7257 excluding any Lvalue Transformation; the identity
7258 conversion sequence is considered to be a subsequence of
7259 any non-identity conversion sequence */
7262 while (t1->kind != ck_identity)
7264 from_type1 = t1->type;
7267 while (t2->kind != ck_identity)
7269 from_type2 = t2->type;
7272 /* One sequence can only be a subsequence of the other if they start with
7273 the same type. They can start with different types when comparing the
7274 second standard conversion sequence in two user-defined conversion
7276 if (same_type_p (from_type1, from_type2))
7278 if (is_subseq (ics1, ics2))
7280 if (is_subseq (ics2, ics1))
7288 --the rank of S1 is better than the rank of S2 (by the rules
7291 Standard conversion sequences are ordered by their ranks: an Exact
7292 Match is a better conversion than a Promotion, which is a better
7293 conversion than a Conversion.
7295 Two conversion sequences with the same rank are indistinguishable
7296 unless one of the following rules applies:
7298 --A conversion that does not a convert a pointer, pointer to member,
7299 or std::nullptr_t to bool is better than one that does.
7301 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
7302 so that we do not have to check it explicitly. */
7303 if (ics1->rank < ics2->rank)
7305 else if (ics2->rank < ics1->rank)
7308 to_type1 = ics1->type;
7309 to_type2 = ics2->type;
7311 /* A conversion from scalar arithmetic type to complex is worse than a
7312 conversion between scalar arithmetic types. */
7313 if (same_type_p (from_type1, from_type2)
7314 && ARITHMETIC_TYPE_P (from_type1)
7315 && ARITHMETIC_TYPE_P (to_type1)
7316 && ARITHMETIC_TYPE_P (to_type2)
7317 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
7318 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
7320 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
7326 if (TYPE_PTR_P (from_type1)
7327 && TYPE_PTR_P (from_type2)
7328 && TYPE_PTR_P (to_type1)
7329 && TYPE_PTR_P (to_type2))
7331 deref_from_type1 = TREE_TYPE (from_type1);
7332 deref_from_type2 = TREE_TYPE (from_type2);
7333 deref_to_type1 = TREE_TYPE (to_type1);
7334 deref_to_type2 = TREE_TYPE (to_type2);
7336 /* The rules for pointers to members A::* are just like the rules
7337 for pointers A*, except opposite: if B is derived from A then
7338 A::* converts to B::*, not vice versa. For that reason, we
7339 switch the from_ and to_ variables here. */
7340 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
7341 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
7342 || (TYPE_PTRMEMFUNC_P (from_type1)
7343 && TYPE_PTRMEMFUNC_P (from_type2)
7344 && TYPE_PTRMEMFUNC_P (to_type1)
7345 && TYPE_PTRMEMFUNC_P (to_type2)))
7347 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
7348 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
7349 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
7350 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
7353 if (deref_from_type1 != NULL_TREE
7354 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
7355 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
7357 /* This was one of the pointer or pointer-like conversions.
7361 --If class B is derived directly or indirectly from class A,
7362 conversion of B* to A* is better than conversion of B* to
7363 void*, and conversion of A* to void* is better than
7364 conversion of B* to void*. */
7365 if (TREE_CODE (deref_to_type1) == VOID_TYPE
7366 && TREE_CODE (deref_to_type2) == VOID_TYPE)
7368 if (is_properly_derived_from (deref_from_type1,
7371 else if (is_properly_derived_from (deref_from_type2,
7375 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
7376 || TREE_CODE (deref_to_type2) == VOID_TYPE)
7378 if (same_type_p (deref_from_type1, deref_from_type2))
7380 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
7382 if (is_properly_derived_from (deref_from_type1,
7386 /* We know that DEREF_TO_TYPE1 is `void' here. */
7387 else if (is_properly_derived_from (deref_from_type1,
7392 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
7393 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
7397 --If class B is derived directly or indirectly from class A
7398 and class C is derived directly or indirectly from B,
7400 --conversion of C* to B* is better than conversion of C* to
7403 --conversion of B* to A* is better than conversion of C* to
7405 if (same_type_p (deref_from_type1, deref_from_type2))
7407 if (is_properly_derived_from (deref_to_type1,
7410 else if (is_properly_derived_from (deref_to_type2,
7414 else if (same_type_p (deref_to_type1, deref_to_type2))
7416 if (is_properly_derived_from (deref_from_type2,
7419 else if (is_properly_derived_from (deref_from_type1,
7425 else if (CLASS_TYPE_P (non_reference (from_type1))
7426 && same_type_p (from_type1, from_type2))
7428 tree from = non_reference (from_type1);
7432 --binding of an expression of type C to a reference of type
7433 B& is better than binding an expression of type C to a
7434 reference of type A&
7436 --conversion of C to B is better than conversion of C to A, */
7437 if (is_properly_derived_from (from, to_type1)
7438 && is_properly_derived_from (from, to_type2))
7440 if (is_properly_derived_from (to_type1, to_type2))
7442 else if (is_properly_derived_from (to_type2, to_type1))
7446 else if (CLASS_TYPE_P (non_reference (to_type1))
7447 && same_type_p (to_type1, to_type2))
7449 tree to = non_reference (to_type1);
7453 --binding of an expression of type B to a reference of type
7454 A& is better than binding an expression of type C to a
7455 reference of type A&,
7457 --conversion of B to A is better than conversion of C to A */
7458 if (is_properly_derived_from (from_type1, to)
7459 && is_properly_derived_from (from_type2, to))
7461 if (is_properly_derived_from (from_type2, from_type1))
7463 else if (is_properly_derived_from (from_type1, from_type2))
7470 --S1 and S2 differ only in their qualification conversion and yield
7471 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
7472 qualification signature of type T1 is a proper subset of the cv-
7473 qualification signature of type T2 */
7474 if (ics1->kind == ck_qual
7475 && ics2->kind == ck_qual
7476 && same_type_p (from_type1, from_type2))
7478 int result = comp_cv_qual_signature (to_type1, to_type2);
7485 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
7486 to an implicit object parameter, and either S1 binds an lvalue reference
7487 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
7488 reference to an rvalue and S2 binds an lvalue reference
7489 (C++0x draft standard, 13.3.3.2)
7491 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
7492 types to which the references refer are the same type except for
7493 top-level cv-qualifiers, and the type to which the reference
7494 initialized by S2 refers is more cv-qualified than the type to
7495 which the reference initialized by S1 refers */
7497 if (ref_conv1 && ref_conv2)
7499 if (!ref_conv1->this_p && !ref_conv2->this_p
7500 && (TYPE_REF_IS_RVALUE (ref_conv1->type)
7501 != TYPE_REF_IS_RVALUE (ref_conv2->type)))
7503 if (ref_conv1->rvaluedness_matches_p)
7505 if (ref_conv2->rvaluedness_matches_p)
7509 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
7510 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
7511 TREE_TYPE (ref_conv1->type));
7514 /* Neither conversion sequence is better than the other. */
7518 /* The source type for this standard conversion sequence. */
7521 source_type (conversion *t)
7523 for (;; t = t->u.next)
7525 if (t->kind == ck_user
7526 || t->kind == ck_ambig
7527 || t->kind == ck_identity)
7533 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7534 a pointer to LOSER and re-running joust to produce the warning if WINNER
7535 is actually used. */
7538 add_warning (struct z_candidate *winner, struct z_candidate *loser)
7540 candidate_warning *cw = (candidate_warning *)
7541 conversion_obstack_alloc (sizeof (candidate_warning));
7543 cw->next = winner->warnings;
7544 winner->warnings = cw;
7547 /* Compare two candidates for overloading as described in
7548 [over.match.best]. Return values:
7550 1: cand1 is better than cand2
7551 -1: cand2 is better than cand1
7552 0: cand1 and cand2 are indistinguishable */
7555 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
7558 int off1 = 0, off2 = 0;
7562 /* Candidates that involve bad conversions are always worse than those
7564 if (cand1->viable > cand2->viable)
7566 if (cand1->viable < cand2->viable)
7569 /* If we have two pseudo-candidates for conversions to the same type,
7570 or two candidates for the same function, arbitrarily pick one. */
7571 if (cand1->fn == cand2->fn
7572 && (IS_TYPE_OR_DECL_P (cand1->fn)))
7575 /* a viable function F1
7576 is defined to be a better function than another viable function F2 if
7577 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7578 ICSi(F2), and then */
7580 /* for some argument j, ICSj(F1) is a better conversion sequence than
7583 /* For comparing static and non-static member functions, we ignore
7584 the implicit object parameter of the non-static function. The
7585 standard says to pretend that the static function has an object
7586 parm, but that won't work with operator overloading. */
7587 len = cand1->num_convs;
7588 if (len != cand2->num_convs)
7590 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
7591 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
7593 gcc_assert (static_1 != static_2);
7604 for (i = 0; i < len; ++i)
7606 conversion *t1 = cand1->convs[i + off1];
7607 conversion *t2 = cand2->convs[i + off2];
7608 int comp = compare_ics (t1, t2);
7613 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
7614 == cr_std + cr_promotion)
7615 && t1->kind == ck_std
7616 && t2->kind == ck_std
7617 && TREE_CODE (t1->type) == INTEGER_TYPE
7618 && TREE_CODE (t2->type) == INTEGER_TYPE
7619 && (TYPE_PRECISION (t1->type)
7620 == TYPE_PRECISION (t2->type))
7621 && (TYPE_UNSIGNED (t1->u.next->type)
7622 || (TREE_CODE (t1->u.next->type)
7625 tree type = t1->u.next->type;
7627 struct z_candidate *w, *l;
7629 type1 = t1->type, type2 = t2->type,
7630 w = cand1, l = cand2;
7632 type1 = t2->type, type2 = t1->type,
7633 w = cand2, l = cand1;
7637 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
7638 type, type1, type2);
7639 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
7645 if (winner && comp != winner)
7654 /* warn about confusing overload resolution for user-defined conversions,
7655 either between a constructor and a conversion op, or between two
7657 if (winner && warn_conversion && cand1->second_conv
7658 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
7659 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
7661 struct z_candidate *w, *l;
7662 bool give_warning = false;
7665 w = cand1, l = cand2;
7667 w = cand2, l = cand1;
7669 /* We don't want to complain about `X::operator T1 ()'
7670 beating `X::operator T2 () const', when T2 is a no less
7671 cv-qualified version of T1. */
7672 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
7673 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
7675 tree t = TREE_TYPE (TREE_TYPE (l->fn));
7676 tree f = TREE_TYPE (TREE_TYPE (w->fn));
7678 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
7683 if (!comp_ptr_ttypes (t, f))
7684 give_warning = true;
7687 give_warning = true;
7693 tree source = source_type (w->convs[0]);
7694 if (! DECL_CONSTRUCTOR_P (w->fn))
7695 source = TREE_TYPE (source);
7696 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
7697 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
7698 source, w->second_conv->type))
7700 inform (input_location, " because conversion sequence for the argument is better");
7711 F1 is a non-template function and F2 is a template function
7714 if (!cand1->template_decl && cand2->template_decl)
7716 else if (cand1->template_decl && !cand2->template_decl)
7720 F1 and F2 are template functions and the function template for F1 is
7721 more specialized than the template for F2 according to the partial
7724 if (cand1->template_decl && cand2->template_decl)
7726 winner = more_specialized_fn
7727 (TI_TEMPLATE (cand1->template_decl),
7728 TI_TEMPLATE (cand2->template_decl),
7729 /* [temp.func.order]: The presence of unused ellipsis and default
7730 arguments has no effect on the partial ordering of function
7731 templates. add_function_candidate() will not have
7732 counted the "this" argument for constructors. */
7733 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
7739 the context is an initialization by user-defined conversion (see
7740 _dcl.init_ and _over.match.user_) and the standard conversion
7741 sequence from the return type of F1 to the destination type (i.e.,
7742 the type of the entity being initialized) is a better conversion
7743 sequence than the standard conversion sequence from the return type
7744 of F2 to the destination type. */
7746 if (cand1->second_conv)
7748 winner = compare_ics (cand1->second_conv, cand2->second_conv);
7753 /* Check whether we can discard a builtin candidate, either because we
7754 have two identical ones or matching builtin and non-builtin candidates.
7756 (Pedantically in the latter case the builtin which matched the user
7757 function should not be added to the overload set, but we spot it here.
7760 ... the builtin candidates include ...
7761 - do not have the same parameter type list as any non-template
7762 non-member candidate. */
7764 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
7765 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
7767 for (i = 0; i < len; ++i)
7768 if (!same_type_p (cand1->convs[i]->type,
7769 cand2->convs[i]->type))
7771 if (i == cand1->num_convs)
7773 if (cand1->fn == cand2->fn)
7774 /* Two built-in candidates; arbitrarily pick one. */
7776 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
7777 /* cand1 is built-in; prefer cand2. */
7780 /* cand2 is built-in; prefer cand1. */
7785 /* If the two function declarations represent the same function (this can
7786 happen with declarations in multiple scopes and arg-dependent lookup),
7787 arbitrarily choose one. But first make sure the default args we're
7789 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
7790 && equal_functions (cand1->fn, cand2->fn))
7792 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
7793 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
7795 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
7797 for (i = 0; i < len; ++i)
7799 /* Don't crash if the fn is variadic. */
7802 parms1 = TREE_CHAIN (parms1);
7803 parms2 = TREE_CHAIN (parms2);
7807 parms1 = TREE_CHAIN (parms1);
7809 parms2 = TREE_CHAIN (parms2);
7813 if (!cp_tree_equal (TREE_PURPOSE (parms1),
7814 TREE_PURPOSE (parms2)))
7818 permerror (input_location, "default argument mismatch in "
7819 "overload resolution");
7820 inform (input_location,
7821 " candidate 1: %q+#F", cand1->fn);
7822 inform (input_location,
7823 " candidate 2: %q+#F", cand2->fn);
7826 add_warning (cand1, cand2);
7829 parms1 = TREE_CHAIN (parms1);
7830 parms2 = TREE_CHAIN (parms2);
7838 /* Extension: If the worst conversion for one candidate is worse than the
7839 worst conversion for the other, take the first. */
7842 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
7843 struct z_candidate *w = 0, *l = 0;
7845 for (i = 0; i < len; ++i)
7847 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
7848 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
7849 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
7850 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
7853 winner = 1, w = cand1, l = cand2;
7855 winner = -1, w = cand2, l = cand1;
7858 /* Don't choose a deleted function over ambiguity. */
7859 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
7863 pedwarn (input_location, 0,
7864 "ISO C++ says that these are ambiguous, even "
7865 "though the worst conversion for the first is better than "
7866 "the worst conversion for the second:");
7867 print_z_candidate (_("candidate 1:"), w);
7868 print_z_candidate (_("candidate 2:"), l);
7876 gcc_assert (!winner);
7880 /* Given a list of candidates for overloading, find the best one, if any.
7881 This algorithm has a worst case of O(2n) (winner is last), and a best
7882 case of O(n/2) (totally ambiguous); much better than a sorting
7885 static struct z_candidate *
7886 tourney (struct z_candidate *candidates)
7888 struct z_candidate *champ = candidates, *challenger;
7890 int champ_compared_to_predecessor = 0;
7892 /* Walk through the list once, comparing each current champ to the next
7893 candidate, knocking out a candidate or two with each comparison. */
7895 for (challenger = champ->next; challenger; )
7897 fate = joust (champ, challenger, 0);
7899 challenger = challenger->next;
7904 champ = challenger->next;
7907 champ_compared_to_predecessor = 0;
7912 champ_compared_to_predecessor = 1;
7915 challenger = champ->next;
7919 /* Make sure the champ is better than all the candidates it hasn't yet
7920 been compared to. */
7922 for (challenger = candidates;
7924 && !(champ_compared_to_predecessor && challenger->next == champ);
7925 challenger = challenger->next)
7927 fate = joust (champ, challenger, 0);
7935 /* Returns nonzero if things of type FROM can be converted to TO. */
7938 can_convert (tree to, tree from)
7940 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT);
7943 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7946 can_convert_arg (tree to, tree from, tree arg, int flags)
7952 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7953 p = conversion_obstack_alloc (0);
7955 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
7957 ok_p = (t && !t->bad_p);
7959 /* Free all the conversions we allocated. */
7960 obstack_free (&conversion_obstack, p);
7965 /* Like can_convert_arg, but allows dubious conversions as well. */
7968 can_convert_arg_bad (tree to, tree from, tree arg, int flags)
7973 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7974 p = conversion_obstack_alloc (0);
7975 /* Try to perform the conversion. */
7976 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
7978 /* Free all the conversions we allocated. */
7979 obstack_free (&conversion_obstack, p);
7984 /* Convert EXPR to TYPE. Return the converted expression.
7986 Note that we allow bad conversions here because by the time we get to
7987 this point we are committed to doing the conversion. If we end up
7988 doing a bad conversion, convert_like will complain. */
7991 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags)
7996 if (error_operand_p (expr))
7997 return error_mark_node;
7999 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8000 p = conversion_obstack_alloc (0);
8002 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8008 if (complain & tf_error)
8010 /* If expr has unknown type, then it is an overloaded function.
8011 Call instantiate_type to get good error messages. */
8012 if (TREE_TYPE (expr) == unknown_type_node)
8013 instantiate_type (type, expr, complain);
8014 else if (invalid_nonstatic_memfn_p (expr, complain))
8015 /* We gave an error. */;
8017 error ("could not convert %qE to %qT", expr, type);
8019 expr = error_mark_node;
8021 else if (processing_template_decl)
8023 /* In a template, we are only concerned about determining the
8024 type of non-dependent expressions, so we do not have to
8025 perform the actual conversion. */
8026 if (TREE_TYPE (expr) != type)
8027 expr = build_nop (type, expr);
8030 expr = convert_like (conv, expr, complain);
8032 /* Free all the conversions we allocated. */
8033 obstack_free (&conversion_obstack, p);
8039 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
8041 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT);
8044 /* Convert EXPR to TYPE (as a direct-initialization) if that is
8045 permitted. If the conversion is valid, the converted expression is
8046 returned. Otherwise, NULL_TREE is returned, except in the case
8047 that TYPE is a class type; in that case, an error is issued. If
8048 C_CAST_P is true, then this direction initialization is taking
8049 place as part of a static_cast being attempted as part of a C-style
8053 perform_direct_initialization_if_possible (tree type,
8056 tsubst_flags_t complain)
8061 if (type == error_mark_node || error_operand_p (expr))
8062 return error_mark_node;
8065 If the destination type is a (possibly cv-qualified) class type:
8067 -- If the initialization is direct-initialization ...,
8068 constructors are considered. ... If no constructor applies, or
8069 the overload resolution is ambiguous, the initialization is
8071 if (CLASS_TYPE_P (type))
8073 VEC(tree,gc) *args = make_tree_vector_single (expr);
8074 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
8075 &args, type, LOOKUP_NORMAL, complain);
8076 release_tree_vector (args);
8077 return build_cplus_new (type, expr);
8080 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8081 p = conversion_obstack_alloc (0);
8083 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8086 if (!conv || conv->bad_p)
8089 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
8090 /*issue_conversion_warnings=*/false,
8094 /* Free all the conversions we allocated. */
8095 obstack_free (&conversion_obstack, p);
8100 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
8101 is being bound to a temporary. Create and return a new VAR_DECL
8102 with the indicated TYPE; this variable will store the value to
8103 which the reference is bound. */
8106 make_temporary_var_for_ref_to_temp (tree decl, tree type)
8110 /* Create the variable. */
8111 var = create_temporary_var (type);
8113 /* Register the variable. */
8114 if (TREE_STATIC (decl))
8116 /* Namespace-scope or local static; give it a mangled name. */
8119 TREE_STATIC (var) = 1;
8120 name = mangle_ref_init_variable (decl);
8121 DECL_NAME (var) = name;
8122 SET_DECL_ASSEMBLER_NAME (var, name);
8123 var = pushdecl_top_level (var);
8126 /* Create a new cleanup level if necessary. */
8127 maybe_push_cleanup_level (type);
8132 /* EXPR is the initializer for a variable DECL of reference or
8133 std::initializer_list type. Create, push and return a new VAR_DECL
8134 for the initializer so that it will live as long as DECL. Any
8135 cleanup for the new variable is returned through CLEANUP, and the
8136 code to initialize the new variable is returned through INITP. */
8139 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp)
8145 /* Create the temporary variable. */
8146 type = TREE_TYPE (expr);
8147 var = make_temporary_var_for_ref_to_temp (decl, type);
8148 layout_decl (var, 0);
8149 /* If the rvalue is the result of a function call it will be
8150 a TARGET_EXPR. If it is some other construct (such as a
8151 member access expression where the underlying object is
8152 itself the result of a function call), turn it into a
8153 TARGET_EXPR here. It is important that EXPR be a
8154 TARGET_EXPR below since otherwise the INIT_EXPR will
8155 attempt to make a bitwise copy of EXPR to initialize
8157 if (TREE_CODE (expr) != TARGET_EXPR)
8158 expr = get_target_expr (expr);
8160 /* If the initializer is constant, put it in DECL_INITIAL so we get
8161 static initialization and use in constant expressions. */
8162 init = maybe_constant_init (expr);
8163 if (TREE_CONSTANT (init))
8165 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
8167 /* 5.19 says that a constant expression can include an
8168 lvalue-rvalue conversion applied to "a glvalue of literal type
8169 that refers to a non-volatile temporary object initialized
8170 with a constant expression". Rather than try to communicate
8171 that this VAR_DECL is a temporary, just mark it constexpr.
8173 Currently this is only useful for initializer_list temporaries,
8174 since reference vars can't appear in constant expressions. */
8175 DECL_DECLARED_CONSTEXPR_P (var) = true;
8176 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
8177 TREE_CONSTANT (var) = true;
8179 DECL_INITIAL (var) = init;
8183 /* Create the INIT_EXPR that will initialize the temporary
8185 init = build2 (INIT_EXPR, type, var, expr);
8186 if (at_function_scope_p ())
8188 add_decl_expr (var);
8190 if (TREE_STATIC (var))
8191 init = add_stmt_to_compound (init, register_dtor_fn (var));
8193 *cleanup = cxx_maybe_build_cleanup (var);
8195 /* We must be careful to destroy the temporary only
8196 after its initialization has taken place. If the
8197 initialization throws an exception, then the
8198 destructor should not be run. We cannot simply
8199 transform INIT into something like:
8201 (INIT, ({ CLEANUP_STMT; }))
8203 because emit_local_var always treats the
8204 initializer as a full-expression. Thus, the
8205 destructor would run too early; it would run at the
8206 end of initializing the reference variable, rather
8207 than at the end of the block enclosing the
8210 The solution is to pass back a cleanup expression
8211 which the caller is responsible for attaching to
8212 the statement tree. */
8216 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
8217 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
8218 static_aggregates = tree_cons (NULL_TREE, var,
8226 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
8227 initializing a variable of that TYPE. If DECL is non-NULL, it is
8228 the VAR_DECL being initialized with the EXPR. (In that case, the
8229 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
8230 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
8231 return, if *CLEANUP is no longer NULL, it will be an expression
8232 that should be pushed as a cleanup after the returned expression
8233 is used to initialize DECL.
8235 Return the converted expression. */
8238 initialize_reference (tree type, tree expr, tree decl, tree *cleanup,
8239 tsubst_flags_t complain)
8244 if (type == error_mark_node || error_operand_p (expr))
8245 return error_mark_node;
8247 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8248 p = conversion_obstack_alloc (0);
8250 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
8252 if (!conv || conv->bad_p)
8254 if (complain & tf_error)
8256 if (!CP_TYPE_CONST_P (TREE_TYPE (type))
8257 && !TYPE_REF_IS_RVALUE (type)
8258 && !real_lvalue_p (expr))
8259 error ("invalid initialization of non-const reference of "
8260 "type %qT from an rvalue of type %qT",
8261 type, TREE_TYPE (expr));
8263 error ("invalid initialization of reference of type "
8264 "%qT from expression of type %qT", type,
8267 return error_mark_node;
8270 /* If DECL is non-NULL, then this special rule applies:
8274 The temporary to which the reference is bound or the temporary
8275 that is the complete object to which the reference is bound
8276 persists for the lifetime of the reference.
8278 The temporaries created during the evaluation of the expression
8279 initializing the reference, except the temporary to which the
8280 reference is bound, are destroyed at the end of the
8281 full-expression in which they are created.
8283 In that case, we store the converted expression into a new
8284 VAR_DECL in a new scope.
8286 However, we want to be careful not to create temporaries when
8287 they are not required. For example, given:
8290 struct D : public B {};
8294 there is no need to copy the return value from "f"; we can just
8295 extend its lifetime. Similarly, given:
8298 struct T { operator S(); };
8302 we can extend the lifetime of the return value of the conversion
8304 gcc_assert (conv->kind == ck_ref_bind);
8308 tree base_conv_type;
8310 /* Skip over the REF_BIND. */
8311 conv = conv->u.next;
8312 /* If the next conversion is a BASE_CONV, skip that too -- but
8313 remember that the conversion was required. */
8314 if (conv->kind == ck_base)
8316 base_conv_type = conv->type;
8317 conv = conv->u.next;
8320 base_conv_type = NULL_TREE;
8321 /* Perform the remainder of the conversion. */
8322 expr = convert_like_real (conv, expr,
8323 /*fn=*/NULL_TREE, /*argnum=*/0,
8325 /*issue_conversion_warnings=*/true,
8327 tf_warning_or_error);
8328 if (error_operand_p (expr))
8329 expr = error_mark_node;
8332 if (!lvalue_or_rvalue_with_address_p (expr))
8335 var = set_up_extended_ref_temp (decl, expr, cleanup, &init);
8336 /* Use its address to initialize the reference variable. */
8337 expr = build_address (var);
8339 expr = convert_to_base (expr,
8340 build_pointer_type (base_conv_type),
8341 /*check_access=*/true,
8342 /*nonnull=*/true, complain);
8344 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
8347 /* Take the address of EXPR. */
8348 expr = cp_build_addr_expr (expr, tf_warning_or_error);
8349 /* If a BASE_CONV was required, perform it now. */
8351 expr = (perform_implicit_conversion
8352 (build_pointer_type (base_conv_type), expr,
8353 tf_warning_or_error));
8354 expr = build_nop (type, expr);
8358 /* Perform the conversion. */
8359 expr = convert_like (conv, expr, tf_warning_or_error);
8361 /* Free all the conversions we allocated. */
8362 obstack_free (&conversion_obstack, p);
8367 /* Returns true iff TYPE is some variant of std::initializer_list. */
8370 is_std_init_list (tree type)
8372 /* Look through typedefs. */
8375 type = TYPE_MAIN_VARIANT (type);
8376 return (CLASS_TYPE_P (type)
8377 && CP_TYPE_CONTEXT (type) == std_node
8378 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
8381 /* Returns true iff DECL is a list constructor: i.e. a constructor which
8382 will accept an argument list of a single std::initializer_list<T>. */
8385 is_list_ctor (tree decl)
8387 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
8390 if (!args || args == void_list_node)
8393 arg = non_reference (TREE_VALUE (args));
8394 if (!is_std_init_list (arg))
8397 args = TREE_CHAIN (args);
8399 if (args && args != void_list_node && !TREE_PURPOSE (args))
8400 /* There are more non-defaulted parms. */
8406 #include "gt-cp-call.h"