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 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
805 array type, if such a conversion is possible. */
808 build_array_conv (tree type, tree ctor, int flags)
811 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
812 tree elttype = TREE_TYPE (type);
817 enum conversion_rank rank = cr_exact;
819 if (TYPE_DOMAIN (type))
821 unsigned HOST_WIDE_INT alen = tree_low_cst (array_type_nelts_top (type), 1);
826 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
829 = implicit_conversion (elttype, TREE_TYPE (val), val,
834 if (sub->rank > rank)
836 if (sub->user_conv_p)
842 c = alloc_conversion (ck_aggr);
845 c->user_conv_p = user;
851 /* Build a representation of the identity conversion from EXPR to
852 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
855 build_identity_conv (tree type, tree expr)
859 c = alloc_conversion (ck_identity);
866 /* Converting from EXPR to TYPE was ambiguous in the sense that there
867 were multiple user-defined conversions to accomplish the job.
868 Build a conversion that indicates that ambiguity. */
871 build_ambiguous_conv (tree type, tree expr)
875 c = alloc_conversion (ck_ambig);
883 strip_top_quals (tree t)
885 if (TREE_CODE (t) == ARRAY_TYPE)
887 return cp_build_qualified_type (t, 0);
890 /* Returns the standard conversion path (see [conv]) from type FROM to type
891 TO, if any. For proper handling of null pointer constants, you must
892 also pass the expression EXPR to convert from. If C_CAST_P is true,
893 this conversion is coming from a C-style cast. */
896 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
899 enum tree_code fcode, tcode;
901 bool fromref = false;
904 to = non_reference (to);
905 if (TREE_CODE (from) == REFERENCE_TYPE)
908 from = TREE_TYPE (from);
911 to = strip_top_quals (to);
912 from = strip_top_quals (from);
914 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
915 && expr && type_unknown_p (expr))
917 tsubst_flags_t tflags = tf_conv;
918 if (!(flags & LOOKUP_PROTECT))
919 tflags |= tf_no_access_control;
920 expr = instantiate_type (to, expr, tflags);
921 if (expr == error_mark_node)
923 from = TREE_TYPE (expr);
926 fcode = TREE_CODE (from);
927 tcode = TREE_CODE (to);
929 conv = build_identity_conv (from, expr);
930 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
932 from = type_decays_to (from);
933 fcode = TREE_CODE (from);
934 conv = build_conv (ck_lvalue, from, conv);
936 else if (fromref || (expr && lvalue_p (expr)))
941 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
944 from = strip_top_quals (bitfield_type);
945 fcode = TREE_CODE (from);
948 conv = build_conv (ck_rvalue, from, conv);
949 if (flags & LOOKUP_PREFER_RVALUE)
950 conv->rvaluedness_matches_p = true;
953 /* Allow conversion between `__complex__' data types. */
954 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
956 /* The standard conversion sequence to convert FROM to TO is
957 the standard conversion sequence to perform componentwise
959 conversion *part_conv = standard_conversion
960 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
964 conv = build_conv (part_conv->kind, to, conv);
965 conv->rank = part_conv->rank;
973 if (same_type_p (from, to))
975 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
976 conv->type = qualified_to;
981 A null pointer constant can be converted to a pointer type; ... A
982 null pointer constant of integral type can be converted to an
983 rvalue of type std::nullptr_t. */
984 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to)
985 || NULLPTR_TYPE_P (to))
986 && expr && null_ptr_cst_p (expr))
987 conv = build_conv (ck_std, to, conv);
988 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
989 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
991 /* For backwards brain damage compatibility, allow interconversion of
992 pointers and integers with a pedwarn. */
993 conv = build_conv (ck_std, to, conv);
996 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
998 /* For backwards brain damage compatibility, allow interconversion of
999 enums and integers with a pedwarn. */
1000 conv = build_conv (ck_std, to, conv);
1003 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1004 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
1009 if (tcode == POINTER_TYPE
1010 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
1013 else if (VOID_TYPE_P (TREE_TYPE (to))
1014 && !TYPE_PTRMEM_P (from)
1015 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
1017 tree nfrom = TREE_TYPE (from);
1018 from = build_pointer_type
1019 (cp_build_qualified_type (void_type_node,
1020 cp_type_quals (nfrom)));
1021 conv = build_conv (ck_ptr, from, conv);
1023 else if (TYPE_PTRMEM_P (from))
1025 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1026 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1028 if (DERIVED_FROM_P (fbase, tbase)
1029 && (same_type_ignoring_top_level_qualifiers_p
1030 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
1031 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
1033 from = build_ptrmem_type (tbase,
1034 TYPE_PTRMEM_POINTED_TO_TYPE (from));
1035 conv = build_conv (ck_pmem, from, conv);
1037 else if (!same_type_p (fbase, tbase))
1040 else if (CLASS_TYPE_P (TREE_TYPE (from))
1041 && CLASS_TYPE_P (TREE_TYPE (to))
1044 An rvalue of type "pointer to cv D," where D is a
1045 class type, can be converted to an rvalue of type
1046 "pointer to cv B," where B is a base class (clause
1047 _class.derived_) of D. If B is an inaccessible
1048 (clause _class.access_) or ambiguous
1049 (_class.member.lookup_) base class of D, a program
1050 that necessitates this conversion is ill-formed.
1051 Therefore, we use DERIVED_FROM_P, and do not check
1052 access or uniqueness. */
1053 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
1056 cp_build_qualified_type (TREE_TYPE (to),
1057 cp_type_quals (TREE_TYPE (from)));
1058 from = build_pointer_type (from);
1059 conv = build_conv (ck_ptr, from, conv);
1060 conv->base_p = true;
1063 if (tcode == POINTER_TYPE)
1065 to_pointee = TREE_TYPE (to);
1066 from_pointee = TREE_TYPE (from);
1070 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1071 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1074 if (same_type_p (from, to))
1076 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1077 /* In a C-style cast, we ignore CV-qualification because we
1078 are allowed to perform a static_cast followed by a
1080 conv = build_conv (ck_qual, to, conv);
1081 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1082 conv = build_conv (ck_qual, to, conv);
1083 else if (expr && string_conv_p (to, expr, 0))
1084 /* converting from string constant to char *. */
1085 conv = build_conv (ck_qual, to, conv);
1086 /* Allow conversions among compatible ObjC pointer types (base
1087 conversions have been already handled above). */
1088 else if (c_dialect_objc ()
1089 && objc_compare_types (to, from, -4, NULL_TREE))
1090 conv = build_conv (ck_ptr, to, conv);
1091 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1093 conv = build_conv (ck_ptr, to, conv);
1101 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1103 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1104 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1105 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
1106 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
1108 if (!DERIVED_FROM_P (fbase, tbase)
1109 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
1110 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
1111 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
1112 || cp_type_quals (fbase) != cp_type_quals (tbase))
1115 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase));
1116 from = build_ptrmemfunc_type (build_pointer_type (from));
1117 conv = build_conv (ck_pmem, from, conv);
1118 conv->base_p = true;
1120 else if (tcode == BOOLEAN_TYPE)
1124 An rvalue of arithmetic, unscoped enumeration, pointer, or
1125 pointer to member type can be converted to an rvalue of type
1126 bool. ... An rvalue of type std::nullptr_t can be converted
1127 to an rvalue of type bool; */
1128 if (ARITHMETIC_TYPE_P (from)
1129 || UNSCOPED_ENUM_P (from)
1130 || fcode == POINTER_TYPE
1131 || TYPE_PTR_TO_MEMBER_P (from)
1132 || NULLPTR_TYPE_P (from))
1134 conv = build_conv (ck_std, to, conv);
1135 if (fcode == POINTER_TYPE
1136 || TYPE_PTRMEM_P (from)
1137 || (TYPE_PTRMEMFUNC_P (from)
1138 && conv->rank < cr_pbool)
1139 || NULLPTR_TYPE_P (from))
1140 conv->rank = cr_pbool;
1146 /* We don't check for ENUMERAL_TYPE here because there are no standard
1147 conversions to enum type. */
1148 /* As an extension, allow conversion to complex type. */
1149 else if (ARITHMETIC_TYPE_P (to))
1151 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
1152 || SCOPED_ENUM_P (from))
1154 conv = build_conv (ck_std, to, conv);
1156 /* Give this a better rank if it's a promotion. */
1157 if (same_type_p (to, type_promotes_to (from))
1158 && conv->u.next->rank <= cr_promotion)
1159 conv->rank = cr_promotion;
1161 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1162 && vector_types_convertible_p (from, to, false))
1163 return build_conv (ck_std, to, conv);
1164 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1165 && is_properly_derived_from (from, to))
1167 if (conv->kind == ck_rvalue)
1168 conv = conv->u.next;
1169 conv = build_conv (ck_base, to, conv);
1170 /* The derived-to-base conversion indicates the initialization
1171 of a parameter with base type from an object of a derived
1172 type. A temporary object is created to hold the result of
1173 the conversion unless we're binding directly to a reference. */
1174 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1179 if (flags & LOOKUP_NO_NARROWING)
1180 conv->check_narrowing = true;
1185 /* Returns nonzero if T1 is reference-related to T2. */
1188 reference_related_p (tree t1, tree t2)
1190 if (t1 == error_mark_node || t2 == error_mark_node)
1193 t1 = TYPE_MAIN_VARIANT (t1);
1194 t2 = TYPE_MAIN_VARIANT (t2);
1198 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1199 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1201 return (same_type_p (t1, t2)
1202 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1203 && DERIVED_FROM_P (t1, t2)));
1206 /* Returns nonzero if T1 is reference-compatible with T2. */
1209 reference_compatible_p (tree t1, tree t2)
1213 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1214 reference-related to T2 and cv1 is the same cv-qualification as,
1215 or greater cv-qualification than, cv2. */
1216 return (reference_related_p (t1, t2)
1217 && at_least_as_qualified_p (t1, t2));
1220 /* Determine whether or not the EXPR (of class type S) can be
1221 converted to T as in [over.match.ref]. */
1224 convert_class_to_reference (tree reference_type, tree s, tree expr, int flags)
1230 struct z_candidate *candidates;
1231 struct z_candidate *cand;
1237 conversions = lookup_conversions (s);
1243 Assuming that "cv1 T" is the underlying type of the reference
1244 being initialized, and "cv S" is the type of the initializer
1245 expression, with S a class type, the candidate functions are
1246 selected as follows:
1248 --The conversion functions of S and its base classes are
1249 considered. Those that are not hidden within S and yield type
1250 "reference to cv2 T2", where "cv1 T" is reference-compatible
1251 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1253 The argument list has one argument, which is the initializer
1258 /* Conceptually, we should take the address of EXPR and put it in
1259 the argument list. Unfortunately, however, that can result in
1260 error messages, which we should not issue now because we are just
1261 trying to find a conversion operator. Therefore, we use NULL,
1262 cast to the appropriate type. */
1263 first_arg = build_int_cst (build_pointer_type (s), 0);
1265 t = TREE_TYPE (reference_type);
1267 /* We're performing a user-defined conversion to a desired type, so set
1268 this for the benefit of add_candidates. */
1269 flags |= LOOKUP_NO_CONVERSION;
1271 for (; conversions; conversions = TREE_CHAIN (conversions))
1273 tree fns = TREE_VALUE (conversions);
1274 tree binfo = TREE_PURPOSE (conversions);
1275 struct z_candidate *old_candidates = candidates;;
1277 add_candidates (fns, first_arg, NULL, reference_type,
1279 binfo, TYPE_BINFO (s),
1280 flags, &candidates);
1282 for (cand = candidates; cand != old_candidates; cand = cand->next)
1284 /* Now, see if the conversion function really returns
1285 an lvalue of the appropriate type. From the
1286 point of view of unification, simply returning an
1287 rvalue of the right type is good enough. */
1289 tree t2 = TREE_TYPE (TREE_TYPE (f));
1290 if (cand->viable == 0)
1291 /* Don't bother looking more closely. */;
1292 else if (TREE_CODE (t2) != REFERENCE_TYPE
1293 || !reference_compatible_p (t, TREE_TYPE (t2)))
1295 /* No need to set cand->reason here; this is most likely
1296 an ambiguous match. If it's not, either this candidate
1297 will win, or we will have identified a reason for it
1303 conversion *identity_conv;
1304 /* Build a standard conversion sequence indicating the
1305 binding from the reference type returned by the
1306 function to the desired REFERENCE_TYPE. */
1308 = build_identity_conv (TREE_TYPE (TREE_TYPE
1309 (TREE_TYPE (cand->fn))),
1312 = (direct_reference_binding
1313 (reference_type, identity_conv));
1314 cand->second_conv->rvaluedness_matches_p
1315 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1316 == TYPE_REF_IS_RVALUE (reference_type);
1317 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1319 /* Don't allow binding of lvalues to rvalue references. */
1320 if (TYPE_REF_IS_RVALUE (reference_type)
1321 && !TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn))))
1322 cand->second_conv->bad_p = true;
1327 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1328 /* If none of the conversion functions worked out, let our caller
1333 cand = tourney (candidates);
1337 /* Now that we know that this is the function we're going to use fix
1338 the dummy first argument. */
1339 gcc_assert (cand->first_arg == NULL_TREE
1340 || integer_zerop (cand->first_arg));
1341 cand->first_arg = build_this (expr);
1343 /* Build a user-defined conversion sequence representing the
1345 conv = build_conv (ck_user,
1346 TREE_TYPE (TREE_TYPE (cand->fn)),
1347 build_identity_conv (TREE_TYPE (expr), expr));
1350 if (cand->viable == -1)
1353 /* Merge it with the standard conversion sequence from the
1354 conversion function's return type to the desired type. */
1355 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1357 return cand->second_conv;
1360 /* A reference of the indicated TYPE is being bound directly to the
1361 expression represented by the implicit conversion sequence CONV.
1362 Return a conversion sequence for this binding. */
1365 direct_reference_binding (tree type, conversion *conv)
1369 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1370 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1372 t = TREE_TYPE (type);
1376 When a parameter of reference type binds directly
1377 (_dcl.init.ref_) to an argument expression, the implicit
1378 conversion sequence is the identity conversion, unless the
1379 argument expression has a type that is a derived class of the
1380 parameter type, in which case the implicit conversion sequence is
1381 a derived-to-base Conversion.
1383 If the parameter binds directly to the result of applying a
1384 conversion function to the argument expression, the implicit
1385 conversion sequence is a user-defined conversion sequence
1386 (_over.ics.user_), with the second standard conversion sequence
1387 either an identity conversion or, if the conversion function
1388 returns an entity of a type that is a derived class of the
1389 parameter type, a derived-to-base conversion. */
1390 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1392 /* Represent the derived-to-base conversion. */
1393 conv = build_conv (ck_base, t, conv);
1394 /* We will actually be binding to the base-class subobject in
1395 the derived class, so we mark this conversion appropriately.
1396 That way, convert_like knows not to generate a temporary. */
1397 conv->need_temporary_p = false;
1399 return build_conv (ck_ref_bind, type, conv);
1402 /* Returns the conversion path from type FROM to reference type TO for
1403 purposes of reference binding. For lvalue binding, either pass a
1404 reference type to FROM or an lvalue expression to EXPR. If the
1405 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1406 the conversion returned. If C_CAST_P is true, this
1407 conversion is coming from a C-style cast. */
1410 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1412 conversion *conv = NULL;
1413 tree to = TREE_TYPE (rto);
1418 cp_lvalue_kind is_lvalue = clk_none;
1420 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1422 expr = instantiate_type (to, expr, tf_none);
1423 if (expr == error_mark_node)
1425 from = TREE_TYPE (expr);
1428 if (TREE_CODE (from) == REFERENCE_TYPE)
1430 /* Anything with reference type is an lvalue. */
1431 is_lvalue = clk_ordinary;
1432 from = TREE_TYPE (from);
1435 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1437 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1438 conv = implicit_conversion (to, from, expr, c_cast_p,
1440 if (!CLASS_TYPE_P (to)
1441 && CONSTRUCTOR_NELTS (expr) == 1)
1443 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1444 if (error_operand_p (expr))
1446 from = TREE_TYPE (expr);
1450 if (is_lvalue == clk_none && expr)
1451 is_lvalue = real_lvalue_p (expr);
1454 if ((is_lvalue & clk_bitfield) != 0)
1455 tfrom = unlowered_expr_type (expr);
1457 /* Figure out whether or not the types are reference-related and
1458 reference compatible. We have do do this after stripping
1459 references from FROM. */
1460 related_p = reference_related_p (to, tfrom);
1461 /* If this is a C cast, first convert to an appropriately qualified
1462 type, so that we can later do a const_cast to the desired type. */
1463 if (related_p && c_cast_p
1464 && !at_least_as_qualified_p (to, tfrom))
1465 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1466 compatible_p = reference_compatible_p (to, tfrom);
1468 /* Directly bind reference when target expression's type is compatible with
1469 the reference and expression is an lvalue. In DR391, the wording in
1470 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1471 const and rvalue references to rvalues of compatible class type.
1472 We should also do direct bindings for non-class "rvalues" derived from
1473 rvalue references. */
1476 || (((CP_TYPE_CONST_NON_VOLATILE_P (to)
1477 && !(flags & LOOKUP_NO_TEMP_BIND))
1478 || TYPE_REF_IS_RVALUE (rto))
1479 && (CLASS_TYPE_P (from)
1480 || TREE_CODE (from) == ARRAY_TYPE
1481 || (expr && lvalue_p (expr))))))
1485 If the initializer expression
1487 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1488 is reference-compatible with "cv2 T2,"
1490 the reference is bound directly to the initializer expression
1494 If the initializer expression is an rvalue, with T2 a class type,
1495 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1496 is bound to the object represented by the rvalue or to a sub-object
1497 within that object. */
1499 conv = build_identity_conv (tfrom, expr);
1500 conv = direct_reference_binding (rto, conv);
1502 if (flags & LOOKUP_PREFER_RVALUE)
1503 /* The top-level caller requested that we pretend that the lvalue
1504 be treated as an rvalue. */
1505 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1507 conv->rvaluedness_matches_p
1508 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1510 if ((is_lvalue & clk_bitfield) != 0
1511 || ((is_lvalue & clk_packed) != 0 && !TYPE_PACKED (to)))
1512 /* For the purposes of overload resolution, we ignore the fact
1513 this expression is a bitfield or packed field. (In particular,
1514 [over.ics.ref] says specifically that a function with a
1515 non-const reference parameter is viable even if the
1516 argument is a bitfield.)
1518 However, when we actually call the function we must create
1519 a temporary to which to bind the reference. If the
1520 reference is volatile, or isn't const, then we cannot make
1521 a temporary, so we just issue an error when the conversion
1523 conv->need_temporary_p = true;
1525 /* Don't allow binding of lvalues to rvalue references. */
1526 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1527 && !(flags & LOOKUP_PREFER_RVALUE))
1532 /* [class.conv.fct] A conversion function is never used to convert a
1533 (possibly cv-qualified) object to the (possibly cv-qualified) same
1534 object type (or a reference to it), to a (possibly cv-qualified) base
1535 class of that type (or a reference to it).... */
1536 else if (CLASS_TYPE_P (from) && !related_p
1537 && !(flags & LOOKUP_NO_CONVERSION))
1541 If the initializer expression
1543 -- has a class type (i.e., T2 is a class type) can be
1544 implicitly converted to an lvalue of type "cv3 T3," where
1545 "cv1 T1" is reference-compatible with "cv3 T3". (this
1546 conversion is selected by enumerating the applicable
1547 conversion functions (_over.match.ref_) and choosing the
1548 best one through overload resolution. (_over.match_).
1550 the reference is bound to the lvalue result of the conversion
1551 in the second case. */
1552 conv = convert_class_to_reference (rto, from, expr, flags);
1557 /* From this point on, we conceptually need temporaries, even if we
1558 elide them. Only the cases above are "direct bindings". */
1559 if (flags & LOOKUP_NO_TEMP_BIND)
1564 When a parameter of reference type is not bound directly to an
1565 argument expression, the conversion sequence is the one required
1566 to convert the argument expression to the underlying type of the
1567 reference according to _over.best.ics_. Conceptually, this
1568 conversion sequence corresponds to copy-initializing a temporary
1569 of the underlying type with the argument expression. Any
1570 difference in top-level cv-qualification is subsumed by the
1571 initialization itself and does not constitute a conversion. */
1575 Otherwise, the reference shall be to a non-volatile const type.
1577 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1578 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1583 Otherwise, a temporary of type "cv1 T1" is created and
1584 initialized from the initializer expression using the rules for a
1585 non-reference copy initialization. If T1 is reference-related to
1586 T2, cv1 must be the same cv-qualification as, or greater
1587 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1588 if (related_p && !at_least_as_qualified_p (to, from))
1591 /* We're generating a temporary now, but don't bind any more in the
1592 conversion (specifically, don't slice the temporary returned by a
1593 conversion operator). */
1594 flags |= LOOKUP_NO_TEMP_BIND;
1596 /* Core issue 899: When [copy-]initializing a temporary to be bound
1597 to the first parameter of a copy constructor (12.8) called with
1598 a single argument in the context of direct-initialization,
1599 explicit conversion functions are also considered.
1601 So don't set LOOKUP_ONLYCONVERTING in that case. */
1602 if (!(flags & LOOKUP_COPY_PARM))
1603 flags |= LOOKUP_ONLYCONVERTING;
1606 conv = implicit_conversion (to, from, expr, c_cast_p,
1611 conv = build_conv (ck_ref_bind, rto, conv);
1612 /* This reference binding, unlike those above, requires the
1613 creation of a temporary. */
1614 conv->need_temporary_p = true;
1615 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1620 /* Returns the implicit conversion sequence (see [over.ics]) from type
1621 FROM to type TO. The optional expression EXPR may affect the
1622 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1623 true, this conversion is coming from a C-style cast. */
1626 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1631 if (from == error_mark_node || to == error_mark_node
1632 || expr == error_mark_node)
1635 if (TREE_CODE (to) == REFERENCE_TYPE)
1636 conv = reference_binding (to, from, expr, c_cast_p, flags);
1638 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1643 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1645 if (is_std_init_list (to))
1646 return build_list_conv (to, expr, flags);
1648 /* Allow conversion from an initializer-list with one element to a
1650 if (SCALAR_TYPE_P (to))
1652 int nelts = CONSTRUCTOR_NELTS (expr);
1656 elt = build_value_init (to, tf_none);
1657 else if (nelts == 1)
1658 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1660 elt = error_mark_node;
1662 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1666 conv->check_narrowing = true;
1667 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1668 /* Too many levels of braces, i.e. '{{1}}'. */
1673 else if (TREE_CODE (to) == ARRAY_TYPE)
1674 return build_array_conv (to, expr, flags);
1677 if (expr != NULL_TREE
1678 && (MAYBE_CLASS_TYPE_P (from)
1679 || MAYBE_CLASS_TYPE_P (to))
1680 && (flags & LOOKUP_NO_CONVERSION) == 0)
1682 struct z_candidate *cand;
1683 int convflags = (flags & (LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING
1684 |LOOKUP_NO_NARROWING));
1686 if (CLASS_TYPE_P (to)
1687 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1688 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1689 return build_aggr_conv (to, expr, flags);
1691 cand = build_user_type_conversion_1 (to, expr, convflags);
1693 conv = cand->second_conv;
1695 /* We used to try to bind a reference to a temporary here, but that
1696 is now handled after the recursive call to this function at the end
1697 of reference_binding. */
1704 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1705 functions. ARGS will not be changed until a single candidate is
1708 static struct z_candidate *
1709 add_candidate (struct z_candidate **candidates,
1710 tree fn, tree first_arg, const VEC(tree,gc) *args,
1711 size_t num_convs, conversion **convs,
1712 tree access_path, tree conversion_path,
1713 int viable, struct rejection_reason *reason)
1715 struct z_candidate *cand = (struct z_candidate *)
1716 conversion_obstack_alloc (sizeof (struct z_candidate));
1719 cand->first_arg = first_arg;
1721 cand->convs = convs;
1722 cand->num_convs = num_convs;
1723 cand->access_path = access_path;
1724 cand->conversion_path = conversion_path;
1725 cand->viable = viable;
1726 cand->reason = reason;
1727 cand->next = *candidates;
1733 /* Return the number of remaining arguments in the parameter list
1734 beginning with ARG. */
1737 remaining_arguments (tree arg)
1741 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1742 arg = TREE_CHAIN (arg))
1748 /* Create an overload candidate for the function or method FN called
1749 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1750 FLAGS is passed on to implicit_conversion.
1752 This does not change ARGS.
1754 CTYPE, if non-NULL, is the type we want to pretend this function
1755 comes from for purposes of overload resolution. */
1757 static struct z_candidate *
1758 add_function_candidate (struct z_candidate **candidates,
1759 tree fn, tree ctype, tree first_arg,
1760 const VEC(tree,gc) *args, tree access_path,
1761 tree conversion_path, int flags)
1763 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1767 tree orig_first_arg = first_arg;
1770 struct rejection_reason *reason = NULL;
1772 /* At this point we should not see any functions which haven't been
1773 explicitly declared, except for friend functions which will have
1774 been found using argument dependent lookup. */
1775 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1777 /* The `this', `in_chrg' and VTT arguments to constructors are not
1778 considered in overload resolution. */
1779 if (DECL_CONSTRUCTOR_P (fn))
1781 parmlist = skip_artificial_parms_for (fn, parmlist);
1782 skip = num_artificial_parms_for (fn);
1783 if (skip > 0 && first_arg != NULL_TREE)
1786 first_arg = NULL_TREE;
1792 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0);
1793 convs = alloc_conversions (len);
1795 /* 13.3.2 - Viable functions [over.match.viable]
1796 First, to be a viable function, a candidate function shall have enough
1797 parameters to agree in number with the arguments in the list.
1799 We need to check this first; otherwise, checking the ICSes might cause
1800 us to produce an ill-formed template instantiation. */
1802 parmnode = parmlist;
1803 for (i = 0; i < len; ++i)
1805 if (parmnode == NULL_TREE || parmnode == void_list_node)
1807 parmnode = TREE_CHAIN (parmnode);
1810 if ((i < len && parmnode)
1811 || !sufficient_parms_p (parmnode))
1813 int remaining = remaining_arguments (parmnode);
1815 reason = arity_rejection (first_arg, i + remaining, len);
1817 /* When looking for a function from a subobject from an implicit
1818 copy/move constructor/operator=, don't consider anything that takes (a
1819 reference to) an unrelated type. See c++/44909 and core 1092. */
1820 else if (parmlist && (flags & LOOKUP_DEFAULTED))
1822 if (DECL_CONSTRUCTOR_P (fn))
1824 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
1825 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
1831 parmnode = chain_index (i-1, parmlist);
1832 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
1837 /* This only applies at the top level. */
1838 flags &= ~LOOKUP_DEFAULTED;
1844 /* Second, for F to be a viable function, there shall exist for each
1845 argument an implicit conversion sequence that converts that argument
1846 to the corresponding parameter of F. */
1848 parmnode = parmlist;
1850 for (i = 0; i < len; ++i)
1852 tree arg, argtype, to_type;
1856 if (parmnode == void_list_node)
1859 if (i == 0 && first_arg != NULL_TREE)
1862 arg = VEC_index (tree, args,
1863 i + skip - (first_arg != NULL_TREE ? 1 : 0));
1864 argtype = lvalue_type (arg);
1866 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1867 && ! DECL_CONSTRUCTOR_P (fn));
1871 tree parmtype = TREE_VALUE (parmnode);
1874 parmnode = TREE_CHAIN (parmnode);
1876 /* The type of the implicit object parameter ('this') for
1877 overload resolution is not always the same as for the
1878 function itself; conversion functions are considered to
1879 be members of the class being converted, and functions
1880 introduced by a using-declaration are considered to be
1881 members of the class that uses them.
1883 Since build_over_call ignores the ICS for the `this'
1884 parameter, we can just change the parm type. */
1885 if (ctype && is_this)
1887 parmtype = cp_build_qualified_type
1888 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
1889 parmtype = build_pointer_type (parmtype);
1892 /* Core issue 899: When [copy-]initializing a temporary to be bound
1893 to the first parameter of a copy constructor (12.8) called with
1894 a single argument in the context of direct-initialization,
1895 explicit conversion functions are also considered.
1897 So set LOOKUP_COPY_PARM to let reference_binding know that
1898 it's being called in that context. We generalize the above
1899 to handle move constructors and template constructors as well;
1900 the standardese should soon be updated similarly. */
1901 if (ctype && i == 0 && (len-skip == 1)
1902 && !(flags & LOOKUP_ONLYCONVERTING)
1903 && DECL_CONSTRUCTOR_P (fn)
1904 && parmtype != error_mark_node
1905 && (same_type_ignoring_top_level_qualifiers_p
1906 (non_reference (parmtype), ctype)))
1908 lflags |= LOOKUP_COPY_PARM;
1909 /* We allow user-defined conversions within init-lists, but
1910 not for the copy constructor. */
1911 if (flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1912 lflags |= LOOKUP_NO_CONVERSION;
1915 lflags |= LOOKUP_ONLYCONVERTING;
1917 t = implicit_conversion (parmtype, argtype, arg,
1918 /*c_cast_p=*/false, lflags);
1923 t = build_identity_conv (argtype, arg);
1924 t->ellipsis_p = true;
1935 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
1942 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type);
1947 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
1948 access_path, conversion_path, viable, reason);
1951 /* Create an overload candidate for the conversion function FN which will
1952 be invoked for expression OBJ, producing a pointer-to-function which
1953 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1954 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1955 passed on to implicit_conversion.
1957 Actually, we don't really care about FN; we care about the type it
1958 converts to. There may be multiple conversion functions that will
1959 convert to that type, and we rely on build_user_type_conversion_1 to
1960 choose the best one; so when we create our candidate, we record the type
1961 instead of the function. */
1963 static struct z_candidate *
1964 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1965 tree first_arg, const VEC(tree,gc) *arglist,
1966 tree access_path, tree conversion_path)
1968 tree totype = TREE_TYPE (TREE_TYPE (fn));
1969 int i, len, viable, flags;
1970 tree parmlist, parmnode;
1972 struct rejection_reason *reason;
1974 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1975 parmlist = TREE_TYPE (parmlist);
1976 parmlist = TYPE_ARG_TYPES (parmlist);
1978 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1;
1979 convs = alloc_conversions (len);
1980 parmnode = parmlist;
1982 flags = LOOKUP_IMPLICIT;
1985 /* Don't bother looking up the same type twice. */
1986 if (*candidates && (*candidates)->fn == totype)
1989 for (i = 0; i < len; ++i)
1991 tree arg, argtype, convert_type = NULL_TREE;
1996 else if (i == 1 && first_arg != NULL_TREE)
1999 arg = VEC_index (tree, arglist,
2000 i - (first_arg != NULL_TREE ? 1 : 0) - 1);
2001 argtype = lvalue_type (arg);
2005 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
2007 convert_type = totype;
2009 else if (parmnode == void_list_node)
2013 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2014 /*c_cast_p=*/false, flags);
2015 convert_type = TREE_VALUE (parmnode);
2019 t = build_identity_conv (argtype, arg);
2020 t->ellipsis_p = true;
2021 convert_type = argtype;
2031 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type);
2038 parmnode = TREE_CHAIN (parmnode);
2042 || ! sufficient_parms_p (parmnode))
2044 int remaining = remaining_arguments (parmnode);
2046 reason = arity_rejection (NULL_TREE, i + remaining, len);
2049 return add_candidate (candidates, totype, first_arg, arglist, len, convs,
2050 access_path, conversion_path, viable, reason);
2054 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2055 tree type1, tree type2, tree *args, tree *argtypes,
2063 struct rejection_reason *reason = NULL;
2068 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2069 convs = alloc_conversions (num_convs);
2071 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2072 conversion ops are allowed. We handle that here by just checking for
2073 boolean_type_node because other operators don't ask for it. COND_EXPR
2074 also does contextual conversion to bool for the first operand, but we
2075 handle that in build_conditional_expr, and type1 here is operand 2. */
2076 if (type1 != boolean_type_node)
2077 flags |= LOOKUP_ONLYCONVERTING;
2079 for (i = 0; i < 2; ++i)
2084 t = implicit_conversion (types[i], argtypes[i], args[i],
2085 /*c_cast_p=*/false, flags);
2089 /* We need something for printing the candidate. */
2090 t = build_identity_conv (types[i], NULL_TREE);
2091 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2096 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2101 /* For COND_EXPR we rearranged the arguments; undo that now. */
2104 convs[2] = convs[1];
2105 convs[1] = convs[0];
2106 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2107 /*c_cast_p=*/false, flags);
2113 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2118 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2120 /*access_path=*/NULL_TREE,
2121 /*conversion_path=*/NULL_TREE,
2126 is_complete (tree t)
2128 return COMPLETE_TYPE_P (complete_type (t));
2131 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2134 promoted_arithmetic_type_p (tree type)
2138 In this section, the term promoted integral type is used to refer
2139 to those integral types which are preserved by integral promotion
2140 (including e.g. int and long but excluding e.g. char).
2141 Similarly, the term promoted arithmetic type refers to promoted
2142 integral types plus floating types. */
2143 return ((CP_INTEGRAL_TYPE_P (type)
2144 && same_type_p (type_promotes_to (type), type))
2145 || TREE_CODE (type) == REAL_TYPE);
2148 /* Create any builtin operator overload candidates for the operator in
2149 question given the converted operand types TYPE1 and TYPE2. The other
2150 args are passed through from add_builtin_candidates to
2151 build_builtin_candidate.
2153 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2154 If CODE is requires candidates operands of the same type of the kind
2155 of which TYPE1 and TYPE2 are, we add both candidates
2156 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2159 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2160 enum tree_code code2, tree fnname, tree type1,
2161 tree type2, tree *args, tree *argtypes, int flags)
2165 case POSTINCREMENT_EXPR:
2166 case POSTDECREMENT_EXPR:
2167 args[1] = integer_zero_node;
2168 type2 = integer_type_node;
2177 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2178 and VQ is either volatile or empty, there exist candidate operator
2179 functions of the form
2180 VQ T& operator++(VQ T&);
2181 T operator++(VQ T&, int);
2182 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2183 type other than bool, and VQ is either volatile or empty, there exist
2184 candidate operator functions of the form
2185 VQ T& operator--(VQ T&);
2186 T operator--(VQ T&, int);
2187 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2188 complete object type, and VQ is either volatile or empty, there exist
2189 candidate operator functions of the form
2190 T*VQ& operator++(T*VQ&);
2191 T*VQ& operator--(T*VQ&);
2192 T* operator++(T*VQ&, int);
2193 T* operator--(T*VQ&, int); */
2195 case POSTDECREMENT_EXPR:
2196 case PREDECREMENT_EXPR:
2197 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2199 case POSTINCREMENT_EXPR:
2200 case PREINCREMENT_EXPR:
2201 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2203 type1 = build_reference_type (type1);
2208 /* 7 For every cv-qualified or cv-unqualified object type T, there
2209 exist candidate operator functions of the form
2213 8 For every function type T, there exist candidate operator functions of
2215 T& operator*(T*); */
2218 if (TREE_CODE (type1) == POINTER_TYPE
2219 && !uses_template_parms (TREE_TYPE (type1))
2220 && (TYPE_PTROB_P (type1)
2221 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2225 /* 9 For every type T, there exist candidate operator functions of the form
2228 10For every promoted arithmetic type T, there exist candidate operator
2229 functions of the form
2233 case UNARY_PLUS_EXPR: /* unary + */
2234 if (TREE_CODE (type1) == POINTER_TYPE)
2237 if (ARITHMETIC_TYPE_P (type1))
2241 /* 11For every promoted integral type T, there exist candidate operator
2242 functions of the form
2246 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2250 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2251 is the same type as C2 or is a derived class of C2, T is a complete
2252 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2253 there exist candidate operator functions of the form
2254 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2255 where CV12 is the union of CV1 and CV2. */
2258 if (TREE_CODE (type1) == POINTER_TYPE
2259 && TYPE_PTR_TO_MEMBER_P (type2))
2261 tree c1 = TREE_TYPE (type1);
2262 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2264 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2265 && (TYPE_PTRMEMFUNC_P (type2)
2266 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2271 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2272 didate operator functions of the form
2277 bool operator<(L, R);
2278 bool operator>(L, R);
2279 bool operator<=(L, R);
2280 bool operator>=(L, R);
2281 bool operator==(L, R);
2282 bool operator!=(L, R);
2283 where LR is the result of the usual arithmetic conversions between
2286 14For every pair of types T and I, where T is a cv-qualified or cv-
2287 unqualified complete object type and I is a promoted integral type,
2288 there exist candidate operator functions of the form
2289 T* operator+(T*, I);
2290 T& operator[](T*, I);
2291 T* operator-(T*, I);
2292 T* operator+(I, T*);
2293 T& operator[](I, T*);
2295 15For every T, where T is a pointer to complete object type, there exist
2296 candidate operator functions of the form112)
2297 ptrdiff_t operator-(T, T);
2299 16For every pointer or enumeration type T, there exist candidate operator
2300 functions of the form
2301 bool operator<(T, T);
2302 bool operator>(T, T);
2303 bool operator<=(T, T);
2304 bool operator>=(T, T);
2305 bool operator==(T, T);
2306 bool operator!=(T, T);
2308 17For every pointer to member type T, there exist candidate operator
2309 functions of the form
2310 bool operator==(T, T);
2311 bool operator!=(T, T); */
2314 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2316 if (TYPE_PTROB_P (type1)
2317 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2319 type2 = ptrdiff_type_node;
2323 case TRUNC_DIV_EXPR:
2324 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2330 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2331 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
2333 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
2338 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
2350 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2352 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2354 if (TREE_CODE (type1) == ENUMERAL_TYPE
2355 && TREE_CODE (type2) == ENUMERAL_TYPE)
2357 if (TYPE_PTR_P (type1)
2358 && null_ptr_cst_p (args[1])
2359 && !uses_template_parms (type1))
2364 if (null_ptr_cst_p (args[0])
2365 && TYPE_PTR_P (type2)
2366 && !uses_template_parms (type2))
2374 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2377 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2379 type1 = ptrdiff_type_node;
2382 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2384 type2 = ptrdiff_type_node;
2389 /* 18For every pair of promoted integral types L and R, there exist candi-
2390 date operator functions of the form
2397 where LR is the result of the usual arithmetic conversions between
2400 case TRUNC_MOD_EXPR:
2406 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2410 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2411 type, VQ is either volatile or empty, and R is a promoted arithmetic
2412 type, there exist candidate operator functions of the form
2413 VQ L& operator=(VQ L&, R);
2414 VQ L& operator*=(VQ L&, R);
2415 VQ L& operator/=(VQ L&, R);
2416 VQ L& operator+=(VQ L&, R);
2417 VQ L& operator-=(VQ L&, R);
2419 20For every pair T, VQ), where T is any type and VQ is either volatile
2420 or empty, there exist candidate operator functions of the form
2421 T*VQ& operator=(T*VQ&, T*);
2423 21For every pair T, VQ), where T is a pointer to member type and VQ is
2424 either volatile or empty, there exist candidate operator functions of
2426 VQ T& operator=(VQ T&, T);
2428 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2429 unqualified complete object type, VQ is either volatile or empty, and
2430 I is a promoted integral type, there exist candidate operator func-
2432 T*VQ& operator+=(T*VQ&, I);
2433 T*VQ& operator-=(T*VQ&, I);
2435 23For every triple L, VQ, R), where L is an integral or enumeration
2436 type, VQ is either volatile or empty, and R is a promoted integral
2437 type, there exist candidate operator functions of the form
2439 VQ L& operator%=(VQ L&, R);
2440 VQ L& operator<<=(VQ L&, R);
2441 VQ L& operator>>=(VQ L&, R);
2442 VQ L& operator&=(VQ L&, R);
2443 VQ L& operator^=(VQ L&, R);
2444 VQ L& operator|=(VQ L&, R); */
2451 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2453 type2 = ptrdiff_type_node;
2457 case TRUNC_DIV_EXPR:
2458 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2462 case TRUNC_MOD_EXPR:
2468 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2473 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2475 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2476 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2477 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2478 || ((TYPE_PTRMEMFUNC_P (type1)
2479 || TREE_CODE (type1) == POINTER_TYPE)
2480 && null_ptr_cst_p (args[1])))
2490 type1 = build_reference_type (type1);
2496 For every pair of promoted arithmetic types L and R, there
2497 exist candidate operator functions of the form
2499 LR operator?(bool, L, R);
2501 where LR is the result of the usual arithmetic conversions
2502 between types L and R.
2504 For every type T, where T is a pointer or pointer-to-member
2505 type, there exist candidate operator functions of the form T
2506 operator?(bool, T, T); */
2508 if (promoted_arithmetic_type_p (type1)
2509 && promoted_arithmetic_type_p (type2))
2513 /* Otherwise, the types should be pointers. */
2514 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2515 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2518 /* We don't check that the two types are the same; the logic
2519 below will actually create two candidates; one in which both
2520 parameter types are TYPE1, and one in which both parameter
2528 /* If we're dealing with two pointer types or two enumeral types,
2529 we need candidates for both of them. */
2530 if (type2 && !same_type_p (type1, type2)
2531 && TREE_CODE (type1) == TREE_CODE (type2)
2532 && (TREE_CODE (type1) == REFERENCE_TYPE
2533 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2534 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2535 || TYPE_PTRMEMFUNC_P (type1)
2536 || MAYBE_CLASS_TYPE_P (type1)
2537 || TREE_CODE (type1) == ENUMERAL_TYPE))
2539 build_builtin_candidate
2540 (candidates, fnname, type1, type1, args, argtypes, flags);
2541 build_builtin_candidate
2542 (candidates, fnname, type2, type2, args, argtypes, flags);
2546 build_builtin_candidate
2547 (candidates, fnname, type1, type2, args, argtypes, flags);
2551 type_decays_to (tree type)
2553 if (TREE_CODE (type) == ARRAY_TYPE)
2554 return build_pointer_type (TREE_TYPE (type));
2555 if (TREE_CODE (type) == FUNCTION_TYPE)
2556 return build_pointer_type (type);
2557 if (!MAYBE_CLASS_TYPE_P (type))
2558 type = cv_unqualified (type);
2562 /* There are three conditions of builtin candidates:
2564 1) bool-taking candidates. These are the same regardless of the input.
2565 2) pointer-pair taking candidates. These are generated for each type
2566 one of the input types converts to.
2567 3) arithmetic candidates. According to the standard, we should generate
2568 all of these, but I'm trying not to...
2570 Here we generate a superset of the possible candidates for this particular
2571 case. That is a subset of the full set the standard defines, plus some
2572 other cases which the standard disallows. add_builtin_candidate will
2573 filter out the invalid set. */
2576 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2577 enum tree_code code2, tree fnname, tree *args,
2582 tree type, argtypes[3], t;
2583 /* TYPES[i] is the set of possible builtin-operator parameter types
2584 we will consider for the Ith argument. */
2585 VEC(tree,gc) *types[2];
2588 for (i = 0; i < 3; ++i)
2591 argtypes[i] = unlowered_expr_type (args[i]);
2593 argtypes[i] = NULL_TREE;
2598 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2599 and VQ is either volatile or empty, there exist candidate operator
2600 functions of the form
2601 VQ T& operator++(VQ T&); */
2603 case POSTINCREMENT_EXPR:
2604 case PREINCREMENT_EXPR:
2605 case POSTDECREMENT_EXPR:
2606 case PREDECREMENT_EXPR:
2611 /* 24There also exist candidate operator functions of the form
2612 bool operator!(bool);
2613 bool operator&&(bool, bool);
2614 bool operator||(bool, bool); */
2616 case TRUTH_NOT_EXPR:
2617 build_builtin_candidate
2618 (candidates, fnname, boolean_type_node,
2619 NULL_TREE, args, argtypes, flags);
2622 case TRUTH_ORIF_EXPR:
2623 case TRUTH_ANDIF_EXPR:
2624 build_builtin_candidate
2625 (candidates, fnname, boolean_type_node,
2626 boolean_type_node, args, argtypes, flags);
2648 types[0] = make_tree_vector ();
2649 types[1] = make_tree_vector ();
2651 for (i = 0; i < 2; ++i)
2655 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2659 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2662 convs = lookup_conversions (argtypes[i]);
2664 if (code == COND_EXPR)
2666 if (real_lvalue_p (args[i]))
2667 VEC_safe_push (tree, gc, types[i],
2668 build_reference_type (argtypes[i]));
2670 VEC_safe_push (tree, gc, types[i],
2671 TYPE_MAIN_VARIANT (argtypes[i]));
2677 for (; convs; convs = TREE_CHAIN (convs))
2679 type = TREE_TYPE (convs);
2682 && (TREE_CODE (type) != REFERENCE_TYPE
2683 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2686 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2687 VEC_safe_push (tree, gc, types[i], type);
2689 type = non_reference (type);
2690 if (i != 0 || ! ref1)
2692 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2693 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2694 VEC_safe_push (tree, gc, types[i], type);
2695 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2696 type = type_promotes_to (type);
2699 if (! vec_member (type, types[i]))
2700 VEC_safe_push (tree, gc, types[i], type);
2705 if (code == COND_EXPR && real_lvalue_p (args[i]))
2706 VEC_safe_push (tree, gc, types[i],
2707 build_reference_type (argtypes[i]));
2708 type = non_reference (argtypes[i]);
2709 if (i != 0 || ! ref1)
2711 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2712 if (enum_p && UNSCOPED_ENUM_P (type))
2713 VEC_safe_push (tree, gc, types[i], type);
2714 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2715 type = type_promotes_to (type);
2717 VEC_safe_push (tree, gc, types[i], type);
2721 /* Run through the possible parameter types of both arguments,
2722 creating candidates with those parameter types. */
2723 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t)
2728 if (!VEC_empty (tree, types[1]))
2729 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u)
2730 add_builtin_candidate
2731 (candidates, code, code2, fnname, t,
2732 u, args, argtypes, flags);
2734 add_builtin_candidate
2735 (candidates, code, code2, fnname, t,
2736 NULL_TREE, args, argtypes, flags);
2739 release_tree_vector (types[0]);
2740 release_tree_vector (types[1]);
2744 /* If TMPL can be successfully instantiated as indicated by
2745 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2747 TMPL is the template. EXPLICIT_TARGS are any explicit template
2748 arguments. ARGLIST is the arguments provided at the call-site.
2749 This does not change ARGLIST. The RETURN_TYPE is the desired type
2750 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2751 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2752 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2754 static struct z_candidate*
2755 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2756 tree ctype, tree explicit_targs, tree first_arg,
2757 const VEC(tree,gc) *arglist, tree return_type,
2758 tree access_path, tree conversion_path,
2759 int flags, tree obj, unification_kind_t strict)
2761 int ntparms = DECL_NTPARMS (tmpl);
2762 tree targs = make_tree_vec (ntparms);
2763 unsigned int len = VEC_length (tree, arglist);
2764 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
2765 unsigned int skip_without_in_chrg = 0;
2766 tree first_arg_without_in_chrg = first_arg;
2767 tree *args_without_in_chrg;
2768 unsigned int nargs_without_in_chrg;
2769 unsigned int ia, ix;
2771 struct z_candidate *cand;
2774 struct rejection_reason *reason = NULL;
2776 /* We don't do deduction on the in-charge parameter, the VTT
2777 parameter or 'this'. */
2778 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2780 if (first_arg_without_in_chrg != NULL_TREE)
2781 first_arg_without_in_chrg = NULL_TREE;
2783 ++skip_without_in_chrg;
2786 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2787 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2788 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2790 if (first_arg_without_in_chrg != NULL_TREE)
2791 first_arg_without_in_chrg = NULL_TREE;
2793 ++skip_without_in_chrg;
2796 if (len < skip_without_in_chrg)
2799 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
2800 + (len - skip_without_in_chrg));
2801 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
2803 if (first_arg_without_in_chrg != NULL_TREE)
2805 args_without_in_chrg[ia] = first_arg_without_in_chrg;
2808 for (ix = skip_without_in_chrg;
2809 VEC_iterate (tree, arglist, ix, arg);
2812 args_without_in_chrg[ia] = arg;
2815 gcc_assert (ia == nargs_without_in_chrg);
2817 i = fn_type_unification (tmpl, explicit_targs, targs,
2818 args_without_in_chrg,
2819 nargs_without_in_chrg,
2820 return_type, strict, flags);
2825 fn = instantiate_template (tmpl, targs, tf_none);
2826 if (fn == error_mark_node)
2831 A member function template is never instantiated to perform the
2832 copy of a class object to an object of its class type.
2834 It's a little unclear what this means; the standard explicitly
2835 does allow a template to be used to copy a class. For example,
2840 template <class T> A(const T&);
2843 void g () { A a (f ()); }
2845 the member template will be used to make the copy. The section
2846 quoted above appears in the paragraph that forbids constructors
2847 whose only parameter is (a possibly cv-qualified variant of) the
2848 class type, and a logical interpretation is that the intent was
2849 to forbid the instantiation of member templates which would then
2851 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
2853 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2854 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2859 if (obj != NULL_TREE)
2860 /* Aha, this is a conversion function. */
2861 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist,
2862 access_path, conversion_path);
2864 cand = add_function_candidate (candidates, fn, ctype,
2865 first_arg, arglist, access_path,
2866 conversion_path, flags);
2867 if (DECL_TI_TEMPLATE (fn) != tmpl)
2868 /* This situation can occur if a member template of a template
2869 class is specialized. Then, instantiate_template might return
2870 an instantiation of the specialization, in which case the
2871 DECL_TI_TEMPLATE field will point at the original
2872 specialization. For example:
2874 template <class T> struct S { template <class U> void f(U);
2875 template <> void f(int) {}; };
2879 Here, TMPL will be template <class U> S<double>::f(U).
2880 And, instantiate template will give us the specialization
2881 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2882 for this will point at template <class T> template <> S<T>::f(int),
2883 so that we can find the definition. For the purposes of
2884 overload resolution, however, we want the original TMPL. */
2885 cand->template_decl = build_template_info (tmpl, targs);
2887 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2888 cand->explicit_targs = explicit_targs;
2892 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
2893 access_path, conversion_path, 0, reason);
2897 static struct z_candidate *
2898 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2899 tree explicit_targs, tree first_arg,
2900 const VEC(tree,gc) *arglist, tree return_type,
2901 tree access_path, tree conversion_path, int flags,
2902 unification_kind_t strict)
2905 add_template_candidate_real (candidates, tmpl, ctype,
2906 explicit_targs, first_arg, arglist,
2907 return_type, access_path, conversion_path,
2908 flags, NULL_TREE, strict);
2912 static struct z_candidate *
2913 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2914 tree obj, tree first_arg,
2915 const VEC(tree,gc) *arglist,
2916 tree return_type, tree access_path,
2917 tree conversion_path)
2920 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2921 first_arg, arglist, return_type, access_path,
2922 conversion_path, 0, obj, DEDUCE_CONV);
2925 /* The CANDS are the set of candidates that were considered for
2926 overload resolution. Return the set of viable candidates, or CANDS
2927 if none are viable. If any of the candidates were viable, set
2928 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
2929 considered viable only if it is strictly viable. */
2931 static struct z_candidate*
2932 splice_viable (struct z_candidate *cands,
2936 struct z_candidate *viable;
2937 struct z_candidate **last_viable;
2938 struct z_candidate **cand;
2941 last_viable = &viable;
2942 *any_viable_p = false;
2947 struct z_candidate *c = *cand;
2948 if (strict_p ? c->viable == 1 : c->viable)
2953 last_viable = &c->next;
2954 *any_viable_p = true;
2960 return viable ? viable : cands;
2964 any_strictly_viable (struct z_candidate *cands)
2966 for (; cands; cands = cands->next)
2967 if (cands->viable == 1)
2972 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2973 words, it is about to become the "this" pointer for a member
2974 function call. Take the address of the object. */
2977 build_this (tree obj)
2979 /* In a template, we are only concerned about the type of the
2980 expression, so we can take a shortcut. */
2981 if (processing_template_decl)
2982 return build_address (obj);
2984 return cp_build_addr_expr (obj, tf_warning_or_error);
2987 /* Returns true iff functions are equivalent. Equivalent functions are
2988 not '==' only if one is a function-local extern function or if
2989 both are extern "C". */
2992 equal_functions (tree fn1, tree fn2)
2994 if (TREE_CODE (fn1) != TREE_CODE (fn2))
2996 if (TREE_CODE (fn1) == TEMPLATE_DECL)
2998 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
2999 || DECL_EXTERN_C_FUNCTION_P (fn1))
3000 return decls_match (fn1, fn2);
3004 /* Print information about a candidate being rejected due to INFO. */
3007 print_conversion_rejection (location_t loc, struct conversion_info *info)
3009 if (info->n_arg == -1)
3010 /* Conversion of implicit `this' argument failed. */
3011 inform (loc, " no known conversion for implicit "
3012 "%<this%> parameter from %qT to %qT",
3013 info->from_type, info->to_type);
3015 inform (loc, " no known conversion for argument %d from %qT to %qT",
3016 info->n_arg+1, info->from_type, info->to_type);
3019 /* Print information about one overload candidate CANDIDATE. MSGSTR
3020 is the text to print before the candidate itself.
3022 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3023 to have been run through gettext by the caller. This wart makes
3024 life simpler in print_z_candidates and for the translators. */
3027 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
3029 const char *msg = (msgstr == NULL
3031 : ACONCAT ((msgstr, " ", NULL)));
3032 location_t loc = location_of (candidate->fn);
3034 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
3036 if (candidate->num_convs == 3)
3037 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn,
3038 candidate->convs[0]->type,
3039 candidate->convs[1]->type,
3040 candidate->convs[2]->type);
3041 else if (candidate->num_convs == 2)
3042 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn,
3043 candidate->convs[0]->type,
3044 candidate->convs[1]->type);
3046 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn,
3047 candidate->convs[0]->type);
3049 else if (TYPE_P (candidate->fn))
3050 inform (input_location, "%s%T <conversion>", msg, candidate->fn);
3051 else if (candidate->viable == -1)
3052 inform (loc, "%s%#D <near match>", msg, candidate->fn);
3053 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn)))
3054 inform (loc, "%s%#D <deleted>", msg, candidate->fn);
3056 inform (loc, "%s%#D", msg, candidate->fn);
3057 /* Give the user some information about why this candidate failed. */
3058 if (candidate->reason != NULL)
3060 struct rejection_reason *r = candidate->reason;
3065 inform_n (loc, r->u.arity.expected,
3066 " candidate expects %d argument, %d provided",
3067 " candidate expects %d arguments, %d provided",
3068 r->u.arity.expected, r->u.arity.actual);
3070 case rr_arg_conversion:
3071 print_conversion_rejection (loc, &r->u.conversion);
3073 case rr_bad_arg_conversion:
3074 print_conversion_rejection (loc, &r->u.bad_conversion);
3078 /* This candidate didn't have any issues or we failed to
3079 handle a particular code. Either way... */
3086 print_z_candidates (location_t loc, struct z_candidate *candidates)
3088 struct z_candidate *cand1;
3089 struct z_candidate **cand2;
3095 /* Remove non-viable deleted candidates. */
3097 for (cand2 = &cand1; *cand2; )
3099 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3100 && !(*cand2)->viable
3101 && DECL_DELETED_FN ((*cand2)->fn))
3102 *cand2 = (*cand2)->next;
3104 cand2 = &(*cand2)->next;
3106 /* ...if there are any non-deleted ones. */
3110 /* There may be duplicates in the set of candidates. We put off
3111 checking this condition as long as possible, since we have no way
3112 to eliminate duplicates from a set of functions in less than n^2
3113 time. Now we are about to emit an error message, so it is more
3114 permissible to go slowly. */
3115 for (cand1 = candidates; cand1; cand1 = cand1->next)
3117 tree fn = cand1->fn;
3118 /* Skip builtin candidates and conversion functions. */
3121 cand2 = &cand1->next;
3124 if (DECL_P ((*cand2)->fn)
3125 && equal_functions (fn, (*cand2)->fn))
3126 *cand2 = (*cand2)->next;
3128 cand2 = &(*cand2)->next;
3132 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next)
3135 inform_n (loc, n_candidates, "candidate is:", "candidates are:");
3136 for (; candidates; candidates = candidates->next)
3137 print_z_candidate (NULL, candidates);
3140 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3141 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3142 the result of the conversion function to convert it to the final
3143 desired type. Merge the two sequences into a single sequence,
3144 and return the merged sequence. */
3147 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3151 gcc_assert (user_seq->kind == ck_user);
3153 /* Find the end of the second conversion sequence. */
3155 while ((*t)->kind != ck_identity)
3156 t = &((*t)->u.next);
3158 /* Replace the identity conversion with the user conversion
3162 /* The entire sequence is a user-conversion sequence. */
3163 std_seq->user_conv_p = true;
3168 /* Handle overload resolution for initializing an object of class type from
3169 an initializer list. First we look for a suitable constructor that
3170 takes a std::initializer_list; if we don't find one, we then look for a
3171 non-list constructor.
3173 Parameters are as for add_candidates, except that the arguments are in
3174 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and
3175 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3178 add_list_candidates (tree fns, tree first_arg,
3179 tree init_list, tree totype,
3180 tree explicit_targs, bool template_only,
3181 tree conversion_path, tree access_path,
3183 struct z_candidate **candidates)
3187 gcc_assert (*candidates == NULL);
3189 /* For list-initialization we consider explicit constructors, but
3190 give an error if one is selected. */
3191 flags &= ~LOOKUP_ONLYCONVERTING;
3192 /* And we don't allow narrowing conversions. We also use this flag to
3193 avoid the copy constructor call for copy-list-initialization. */
3194 flags |= LOOKUP_NO_NARROWING;
3196 /* Always use the default constructor if the list is empty (DR 990). */
3197 if (CONSTRUCTOR_NELTS (init_list) == 0
3198 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3200 /* If the class has a list ctor, try passing the list as a single
3201 argument first, but only consider list ctors. */
3202 else if (TYPE_HAS_LIST_CTOR (totype))
3204 flags |= LOOKUP_LIST_ONLY;
3205 args = make_tree_vector_single (init_list);
3206 add_candidates (fns, first_arg, args, NULL_TREE,
3207 explicit_targs, template_only, conversion_path,
3208 access_path, flags, candidates);
3209 if (any_strictly_viable (*candidates))
3213 args = ctor_to_vec (init_list);
3215 /* We aren't looking for list-ctors anymore. */
3216 flags &= ~LOOKUP_LIST_ONLY;
3217 /* We allow more user-defined conversions within an init-list. */
3218 flags &= ~LOOKUP_NO_CONVERSION;
3219 /* But not for the copy ctor. */
3220 flags |= LOOKUP_NO_COPY_CTOR_CONVERSION;
3222 add_candidates (fns, first_arg, args, NULL_TREE,
3223 explicit_targs, template_only, conversion_path,
3224 access_path, flags, candidates);
3227 /* Returns the best overload candidate to perform the requested
3228 conversion. This function is used for three the overloading situations
3229 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3230 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
3231 per [dcl.init.ref], so we ignore temporary bindings. */
3233 static struct z_candidate *
3234 build_user_type_conversion_1 (tree totype, tree expr, int flags)
3236 struct z_candidate *candidates, *cand;
3237 tree fromtype = TREE_TYPE (expr);
3238 tree ctors = NULL_TREE;
3239 tree conv_fns = NULL_TREE;
3240 conversion *conv = NULL;
3241 tree first_arg = NULL_TREE;
3242 VEC(tree,gc) *args = NULL;
3246 /* We represent conversion within a hierarchy using RVALUE_CONV and
3247 BASE_CONV, as specified by [over.best.ics]; these become plain
3248 constructor calls, as specified in [dcl.init]. */
3249 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3250 || !DERIVED_FROM_P (totype, fromtype));
3252 if (MAYBE_CLASS_TYPE_P (totype))
3253 ctors = lookup_fnfields (totype, complete_ctor_identifier, 0);
3255 if (MAYBE_CLASS_TYPE_P (fromtype))
3257 tree to_nonref = non_reference (totype);
3258 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3259 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3260 && DERIVED_FROM_P (to_nonref, fromtype)))
3262 /* [class.conv.fct] A conversion function is never used to
3263 convert a (possibly cv-qualified) object to the (possibly
3264 cv-qualified) same object type (or a reference to it), to a
3265 (possibly cv-qualified) base class of that type (or a
3266 reference to it)... */
3269 conv_fns = lookup_conversions (fromtype);
3273 flags |= LOOKUP_NO_CONVERSION;
3274 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3275 flags |= LOOKUP_NO_NARROWING;
3277 /* It's OK to bind a temporary for converting constructor arguments, but
3278 not in converting the return value of a conversion operator. */
3279 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
3280 flags &= ~LOOKUP_NO_TEMP_BIND;
3284 int ctorflags = flags;
3285 ctors = BASELINK_FUNCTIONS (ctors);
3287 first_arg = build_int_cst (build_pointer_type (totype), 0);
3289 /* We should never try to call the abstract or base constructor
3291 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
3292 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
3294 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3296 /* List-initialization. */
3297 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE,
3298 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3299 ctorflags, &candidates);
3303 args = make_tree_vector_single (expr);
3304 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3305 TYPE_BINFO (totype), TYPE_BINFO (totype),
3306 ctorflags, &candidates);
3309 for (cand = candidates; cand; cand = cand->next)
3311 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3313 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3314 set, then this is copy-initialization. In that case, "The
3315 result of the call is then used to direct-initialize the
3316 object that is the destination of the copy-initialization."
3319 We represent this in the conversion sequence with an
3320 rvalue conversion, which means a constructor call. */
3321 if (TREE_CODE (totype) != REFERENCE_TYPE
3322 && !(convflags & LOOKUP_NO_TEMP_BIND))
3324 = build_conv (ck_rvalue, totype, cand->second_conv);
3329 first_arg = build_this (expr);
3331 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3333 tree conversion_path = TREE_PURPOSE (conv_fns);
3334 struct z_candidate *old_candidates;
3336 /* If we are called to convert to a reference type, we are trying to
3337 find an lvalue binding, so don't even consider temporaries. If
3338 we don't find an lvalue binding, the caller will try again to
3339 look for a temporary binding. */
3340 if (TREE_CODE (totype) == REFERENCE_TYPE)
3341 convflags |= LOOKUP_NO_TEMP_BIND;
3343 old_candidates = candidates;
3344 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3346 conversion_path, TYPE_BINFO (fromtype),
3347 flags, &candidates);
3349 for (cand = candidates; cand != old_candidates; cand = cand->next)
3352 = implicit_conversion (totype,
3353 TREE_TYPE (TREE_TYPE (cand->fn)),
3355 /*c_cast_p=*/false, convflags);
3357 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3358 copy-initialization. In that case, "The result of the
3359 call is then used to direct-initialize the object that is
3360 the destination of the copy-initialization." [dcl.init]
3362 We represent this in the conversion sequence with an
3363 rvalue conversion, which means a constructor call. But
3364 don't add a second rvalue conversion if there's already
3365 one there. Which there really shouldn't be, but it's
3366 harmless since we'd add it here anyway. */
3367 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3368 && !(convflags & LOOKUP_NO_TEMP_BIND))
3369 ics = build_conv (ck_rvalue, totype, ics);
3371 cand->second_conv = ics;
3375 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3377 cand->reason = arg_conversion_rejection (NULL_TREE, -1,
3380 else if (cand->viable == 1 && ics->bad_p)
3382 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3385 = bad_arg_conversion_rejection (NULL_TREE, -1,
3391 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3395 cand = tourney (candidates);
3398 if (flags & LOOKUP_COMPLAIN)
3400 error ("conversion from %qT to %qT is ambiguous",
3402 print_z_candidates (location_of (expr), candidates);
3405 cand = candidates; /* any one will do */
3406 cand->second_conv = build_ambiguous_conv (totype, expr);
3407 cand->second_conv->user_conv_p = true;
3408 if (!any_strictly_viable (candidates))
3409 cand->second_conv->bad_p = true;
3410 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3411 ambiguous conversion is no worse than another user-defined
3417 /* Build the user conversion sequence. */
3420 (DECL_CONSTRUCTOR_P (cand->fn)
3421 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
3422 build_identity_conv (TREE_TYPE (expr), expr));
3425 /* Remember that this was a list-initialization. */
3426 if (flags & LOOKUP_NO_NARROWING)
3427 conv->check_narrowing = true;
3429 /* Combine it with the second conversion sequence. */
3430 cand->second_conv = merge_conversion_sequences (conv,
3433 if (cand->viable == -1)
3434 cand->second_conv->bad_p = true;
3440 build_user_type_conversion (tree totype, tree expr, int flags)
3442 struct z_candidate *cand
3443 = build_user_type_conversion_1 (totype, expr, flags);
3447 if (cand->second_conv->kind == ck_ambig)
3448 return error_mark_node;
3449 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
3450 return convert_from_reference (expr);
3455 /* Subroutine of convert_nontype_argument.
3457 EXPR is an argument for a template non-type parameter of integral or
3458 enumeration type. Do any necessary conversions (that are permitted for
3459 non-type arguments) to convert it to the parameter type.
3461 If conversion is successful, returns the converted expression;
3462 otherwise, returns error_mark_node. */
3465 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain)
3471 if (error_operand_p (expr))
3472 return error_mark_node;
3474 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3476 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3477 p = conversion_obstack_alloc (0);
3479 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
3483 /* for a non-type template-parameter of integral or
3484 enumeration type, integral promotions (4.5) and integral
3485 conversions (4.7) are applied. */
3486 /* It should be sufficient to check the outermost conversion step, since
3487 there are no qualification conversions to integer type. */
3491 /* A conversion function is OK. If it isn't constexpr, we'll
3492 complain later that the argument isn't constant. */
3494 /* The lvalue-to-rvalue conversion is OK. */
3500 t = conv->u.next->type;
3501 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t))
3504 if (complain & tf_error)
3505 error ("conversion from %qT to %qT not considered for "
3506 "non-type template argument", t, type);
3507 /* and fall through. */
3515 expr = convert_like (conv, expr, complain);
3517 expr = error_mark_node;
3519 /* Free all the conversions we allocated. */
3520 obstack_free (&conversion_obstack, p);
3525 /* Do any initial processing on the arguments to a function call. */
3527 static VEC(tree,gc) *
3528 resolve_args (VEC(tree,gc) *args)
3533 FOR_EACH_VEC_ELT (tree, args, ix, arg)
3535 if (error_operand_p (arg))
3537 else if (VOID_TYPE_P (TREE_TYPE (arg)))
3539 error ("invalid use of void expression");
3542 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
3548 /* Perform overload resolution on FN, which is called with the ARGS.
3550 Return the candidate function selected by overload resolution, or
3551 NULL if the event that overload resolution failed. In the case
3552 that overload resolution fails, *CANDIDATES will be the set of
3553 candidates considered, and ANY_VIABLE_P will be set to true or
3554 false to indicate whether or not any of the candidates were
3557 The ARGS should already have gone through RESOLVE_ARGS before this
3558 function is called. */
3560 static struct z_candidate *
3561 perform_overload_resolution (tree fn,
3562 const VEC(tree,gc) *args,
3563 struct z_candidate **candidates,
3566 struct z_candidate *cand;
3567 tree explicit_targs = NULL_TREE;
3568 int template_only = 0;
3571 *any_viable_p = true;
3574 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
3575 || TREE_CODE (fn) == TEMPLATE_DECL
3576 || TREE_CODE (fn) == OVERLOAD
3577 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3579 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3581 explicit_targs = TREE_OPERAND (fn, 1);
3582 fn = TREE_OPERAND (fn, 0);
3586 /* Add the various candidate functions. */
3587 add_candidates (fn, NULL_TREE, args, NULL_TREE,
3588 explicit_targs, template_only,
3589 /*conversion_path=*/NULL_TREE,
3590 /*access_path=*/NULL_TREE,
3594 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3598 cand = tourney (*candidates);
3602 /* Print an error message about being unable to build a call to FN with
3603 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
3604 be located; CANDIDATES is a possibly empty list of such
3608 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p,
3609 struct z_candidate *candidates)
3611 tree name = DECL_NAME (OVL_CURRENT (fn));
3612 location_t loc = location_of (name);
3615 error_at (loc, "no matching function for call to %<%D(%A)%>",
3616 name, build_tree_list_vec (args));
3618 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
3619 name, build_tree_list_vec (args));
3621 print_z_candidates (loc, candidates);
3624 /* Return an expression for a call to FN (a namespace-scope function,
3625 or a static member function) with the ARGS. This may change
3629 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p,
3630 tsubst_flags_t complain)
3632 struct z_candidate *candidates, *cand;
3637 if (args != NULL && *args != NULL)
3639 *args = resolve_args (*args);
3641 return error_mark_node;
3644 /* If this function was found without using argument dependent
3645 lookup, then we want to ignore any undeclared friend
3651 fn = remove_hidden_names (fn);
3654 if (complain & tf_error)
3655 print_error_for_call_failure (orig_fn, *args, false, NULL);
3656 return error_mark_node;
3660 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3661 p = conversion_obstack_alloc (0);
3663 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p);
3667 if (complain & tf_error)
3669 if (!any_viable_p && candidates && ! candidates->next
3670 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
3671 return cp_build_function_call_vec (candidates->fn, args, complain);
3672 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3673 fn = TREE_OPERAND (fn, 0);
3674 print_error_for_call_failure (fn, *args, any_viable_p, candidates);
3676 result = error_mark_node;
3679 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3681 /* Free all the conversions we allocated. */
3682 obstack_free (&conversion_obstack, p);
3687 /* Build a call to a global operator new. FNNAME is the name of the
3688 operator (either "operator new" or "operator new[]") and ARGS are
3689 the arguments provided. This may change ARGS. *SIZE points to the
3690 total number of bytes required by the allocation, and is updated if
3691 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3692 be used. If this function determines that no cookie should be
3693 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3694 non-NULL, it will be set, upon return, to the allocation function
3698 build_operator_new_call (tree fnname, VEC(tree,gc) **args,
3699 tree *size, tree *cookie_size,
3703 struct z_candidate *candidates;
3704 struct z_candidate *cand;
3709 VEC_safe_insert (tree, gc, *args, 0, *size);
3710 *args = resolve_args (*args);
3712 return error_mark_node;
3718 If this lookup fails to find the name, or if the allocated type
3719 is not a class type, the allocation function's name is looked
3720 up in the global scope.
3722 we disregard block-scope declarations of "operator new". */
3723 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
3725 /* Figure out what function is being called. */
3726 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p);
3728 /* If no suitable function could be found, issue an error message
3732 print_error_for_call_failure (fns, *args, any_viable_p, candidates);
3733 return error_mark_node;
3736 /* If a cookie is required, add some extra space. Whether
3737 or not a cookie is required cannot be determined until
3738 after we know which function was called. */
3741 bool use_cookie = true;
3742 if (!abi_version_at_least (2))
3744 /* In G++ 3.2, the check was implemented incorrectly; it
3745 looked at the placement expression, rather than the
3746 type of the function. */
3747 if (VEC_length (tree, *args) == 2
3748 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)),
3756 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3757 /* Skip the size_t parameter. */
3758 arg_types = TREE_CHAIN (arg_types);
3759 /* Check the remaining parameters (if any). */
3761 && TREE_CHAIN (arg_types) == void_list_node
3762 && same_type_p (TREE_VALUE (arg_types),
3766 /* If we need a cookie, adjust the number of bytes allocated. */
3769 /* Update the total size. */
3770 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3771 /* Update the argument list to reflect the adjusted size. */
3772 VEC_replace (tree, *args, 0, *size);
3775 *cookie_size = NULL_TREE;
3778 /* Tell our caller which function we decided to call. */
3782 /* Build the CALL_EXPR. */
3783 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3786 /* Build a new call to operator(). This may change ARGS. */
3789 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain)
3791 struct z_candidate *candidates = 0, *cand;
3792 tree fns, convs, first_mem_arg = NULL_TREE;
3793 tree type = TREE_TYPE (obj);
3795 tree result = NULL_TREE;
3798 if (error_operand_p (obj))
3799 return error_mark_node;
3801 obj = prep_operand (obj);
3803 if (TYPE_PTRMEMFUNC_P (type))
3805 if (complain & tf_error)
3806 /* It's no good looking for an overloaded operator() on a
3807 pointer-to-member-function. */
3808 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3809 return error_mark_node;
3812 if (TYPE_BINFO (type))
3814 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3815 if (fns == error_mark_node)
3816 return error_mark_node;
3821 if (args != NULL && *args != NULL)
3823 *args = resolve_args (*args);
3825 return error_mark_node;
3828 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3829 p = conversion_obstack_alloc (0);
3833 first_mem_arg = build_this (obj);
3835 add_candidates (BASELINK_FUNCTIONS (fns),
3836 first_mem_arg, *args, NULL_TREE,
3838 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
3839 LOOKUP_NORMAL, &candidates);
3842 convs = lookup_conversions (type);
3844 for (; convs; convs = TREE_CHAIN (convs))
3846 tree fns = TREE_VALUE (convs);
3847 tree totype = TREE_TYPE (convs);
3849 if ((TREE_CODE (totype) == POINTER_TYPE
3850 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3851 || (TREE_CODE (totype) == REFERENCE_TYPE
3852 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3853 || (TREE_CODE (totype) == REFERENCE_TYPE
3854 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3855 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3856 for (; fns; fns = OVL_NEXT (fns))
3858 tree fn = OVL_CURRENT (fns);
3860 if (DECL_NONCONVERTING_P (fn))
3863 if (TREE_CODE (fn) == TEMPLATE_DECL)
3864 add_template_conv_candidate
3865 (&candidates, fn, obj, NULL_TREE, *args, totype,
3866 /*access_path=*/NULL_TREE,
3867 /*conversion_path=*/NULL_TREE);
3869 add_conv_candidate (&candidates, fn, obj, NULL_TREE,
3870 *args, /*conversion_path=*/NULL_TREE,
3871 /*access_path=*/NULL_TREE);
3875 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3878 if (complain & tf_error)
3880 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
3881 build_tree_list_vec (*args));
3882 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3884 result = error_mark_node;
3888 cand = tourney (candidates);
3891 if (complain & tf_error)
3893 error ("call of %<(%T) (%A)%> is ambiguous",
3894 TREE_TYPE (obj), build_tree_list_vec (*args));
3895 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3897 result = error_mark_node;
3899 /* Since cand->fn will be a type, not a function, for a conversion
3900 function, we must be careful not to unconditionally look at
3902 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3903 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3904 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3907 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
3909 obj = convert_from_reference (obj);
3910 result = cp_build_function_call_vec (obj, args, complain);
3914 /* Free all the conversions we allocated. */
3915 obstack_free (&conversion_obstack, p);
3921 op_error (enum tree_code code, enum tree_code code2,
3922 tree arg1, tree arg2, tree arg3, bool match)
3926 if (code == MODIFY_EXPR)
3927 opname = assignment_operator_name_info[code2].name;
3929 opname = operator_name_info[code].name;
3935 error ("ambiguous overload for ternary %<operator?:%> "
3936 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3938 error ("no match for ternary %<operator?:%> "
3939 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3942 case POSTINCREMENT_EXPR:
3943 case POSTDECREMENT_EXPR:
3945 error ("ambiguous overload for %<operator%s%> in %<%E%s%>",
3946 opname, arg1, opname);
3948 error ("no match for %<operator%s%> in %<%E%s%>",
3949 opname, arg1, opname);
3954 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>",
3957 error ("no match for %<operator[]%> in %<%E[%E]%>",
3964 error ("ambiguous overload for %qs in %<%s %E%>",
3965 opname, opname, arg1);
3967 error ("no match for %qs in %<%s %E%>",
3968 opname, opname, arg1);
3974 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>",
3975 opname, arg1, opname, arg2);
3977 error ("no match for %<operator%s%> in %<%E %s %E%>",
3978 opname, arg1, opname, arg2);
3981 error ("ambiguous overload for %<operator%s%> in %<%s%E%>",
3982 opname, opname, arg1);
3984 error ("no match for %<operator%s%> in %<%s%E%>",
3985 opname, opname, arg1);
3990 /* Return the implicit conversion sequence that could be used to
3991 convert E1 to E2 in [expr.cond]. */
3994 conditional_conversion (tree e1, tree e2)
3996 tree t1 = non_reference (TREE_TYPE (e1));
3997 tree t2 = non_reference (TREE_TYPE (e2));
4003 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4004 implicitly converted (clause _conv_) to the type "reference to
4005 T2", subject to the constraint that in the conversion the
4006 reference must bind directly (_dcl.init.ref_) to E1. */
4007 if (real_lvalue_p (e2))
4009 conv = implicit_conversion (build_reference_type (t2),
4013 LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING);
4020 If E1 and E2 have class type, and the underlying class types are
4021 the same or one is a base class of the other: E1 can be converted
4022 to match E2 if the class of T2 is the same type as, or a base
4023 class of, the class of T1, and the cv-qualification of T2 is the
4024 same cv-qualification as, or a greater cv-qualification than, the
4025 cv-qualification of T1. If the conversion is applied, E1 is
4026 changed to an rvalue of type T2 that still refers to the original
4027 source class object (or the appropriate subobject thereof). */
4028 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4029 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4031 if (good_base && at_least_as_qualified_p (t2, t1))
4033 conv = build_identity_conv (t1, e1);
4034 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4035 TYPE_MAIN_VARIANT (t2)))
4036 conv = build_conv (ck_base, t2, conv);
4038 conv = build_conv (ck_rvalue, t2, conv);
4047 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4048 converted to the type that expression E2 would have if E2 were
4049 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4050 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4054 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4055 arguments to the conditional expression. */
4058 build_conditional_expr (tree arg1, tree arg2, tree arg3,
4059 tsubst_flags_t complain)
4063 tree result = NULL_TREE;
4064 tree result_type = NULL_TREE;
4065 bool lvalue_p = true;
4066 struct z_candidate *candidates = 0;
4067 struct z_candidate *cand;
4070 /* As a G++ extension, the second argument to the conditional can be
4071 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4072 c'.) If the second operand is omitted, make sure it is
4073 calculated only once. */
4076 if (complain & tf_error)
4077 pedwarn (input_location, OPT_pedantic,
4078 "ISO C++ forbids omitting the middle term of a ?: expression");
4080 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4081 if (real_lvalue_p (arg1))
4082 arg2 = arg1 = stabilize_reference (arg1);
4084 arg2 = arg1 = save_expr (arg1);
4089 The first expression is implicitly converted to bool (clause
4091 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4094 /* If something has already gone wrong, just pass that fact up the
4096 if (error_operand_p (arg1)
4097 || error_operand_p (arg2)
4098 || error_operand_p (arg3))
4099 return error_mark_node;
4103 If either the second or the third operand has type (possibly
4104 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4105 array-to-pointer (_conv.array_), and function-to-pointer
4106 (_conv.func_) standard conversions are performed on the second
4107 and third operands. */
4108 arg2_type = unlowered_expr_type (arg2);
4109 arg3_type = unlowered_expr_type (arg3);
4110 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4112 /* Do the conversions. We don't these for `void' type arguments
4113 since it can't have any effect and since decay_conversion
4114 does not handle that case gracefully. */
4115 if (!VOID_TYPE_P (arg2_type))
4116 arg2 = decay_conversion (arg2);
4117 if (!VOID_TYPE_P (arg3_type))
4118 arg3 = decay_conversion (arg3);
4119 arg2_type = TREE_TYPE (arg2);
4120 arg3_type = TREE_TYPE (arg3);
4124 One of the following shall hold:
4126 --The second or the third operand (but not both) is a
4127 throw-expression (_except.throw_); the result is of the
4128 type of the other and is an rvalue.
4130 --Both the second and the third operands have type void; the
4131 result is of type void and is an rvalue.
4133 We must avoid calling force_rvalue for expressions of type
4134 "void" because it will complain that their value is being
4136 if (TREE_CODE (arg2) == THROW_EXPR
4137 && TREE_CODE (arg3) != THROW_EXPR)
4139 if (!VOID_TYPE_P (arg3_type))
4140 arg3 = force_rvalue (arg3);
4141 arg3_type = TREE_TYPE (arg3);
4142 result_type = arg3_type;
4144 else if (TREE_CODE (arg2) != THROW_EXPR
4145 && TREE_CODE (arg3) == THROW_EXPR)
4147 if (!VOID_TYPE_P (arg2_type))
4148 arg2 = force_rvalue (arg2);
4149 arg2_type = TREE_TYPE (arg2);
4150 result_type = arg2_type;
4152 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
4153 result_type = void_type_node;
4156 if (complain & tf_error)
4158 if (VOID_TYPE_P (arg2_type))
4159 error ("second operand to the conditional operator "
4160 "is of type %<void%>, "
4161 "but the third operand is neither a throw-expression "
4162 "nor of type %<void%>");
4164 error ("third operand to the conditional operator "
4165 "is of type %<void%>, "
4166 "but the second operand is neither a throw-expression "
4167 "nor of type %<void%>");
4169 return error_mark_node;
4173 goto valid_operands;
4177 Otherwise, if the second and third operand have different types,
4178 and either has (possibly cv-qualified) class type, an attempt is
4179 made to convert each of those operands to the type of the other. */
4180 else if (!same_type_p (arg2_type, arg3_type)
4181 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4186 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4187 p = conversion_obstack_alloc (0);
4189 conv2 = conditional_conversion (arg2, arg3);
4190 conv3 = conditional_conversion (arg3, arg2);
4194 If both can be converted, or one can be converted but the
4195 conversion is ambiguous, the program is ill-formed. If
4196 neither can be converted, the operands are left unchanged and
4197 further checking is performed as described below. If exactly
4198 one conversion is possible, that conversion is applied to the
4199 chosen operand and the converted operand is used in place of
4200 the original operand for the remainder of this section. */
4201 if ((conv2 && !conv2->bad_p
4202 && conv3 && !conv3->bad_p)
4203 || (conv2 && conv2->kind == ck_ambig)
4204 || (conv3 && conv3->kind == ck_ambig))
4206 error ("operands to ?: have different types %qT and %qT",
4207 arg2_type, arg3_type);
4208 result = error_mark_node;
4210 else if (conv2 && (!conv2->bad_p || !conv3))
4212 arg2 = convert_like (conv2, arg2, complain);
4213 arg2 = convert_from_reference (arg2);
4214 arg2_type = TREE_TYPE (arg2);
4215 /* Even if CONV2 is a valid conversion, the result of the
4216 conversion may be invalid. For example, if ARG3 has type
4217 "volatile X", and X does not have a copy constructor
4218 accepting a "volatile X&", then even if ARG2 can be
4219 converted to X, the conversion will fail. */
4220 if (error_operand_p (arg2))
4221 result = error_mark_node;
4223 else if (conv3 && (!conv3->bad_p || !conv2))
4225 arg3 = convert_like (conv3, arg3, complain);
4226 arg3 = convert_from_reference (arg3);
4227 arg3_type = TREE_TYPE (arg3);
4228 if (error_operand_p (arg3))
4229 result = error_mark_node;
4232 /* Free all the conversions we allocated. */
4233 obstack_free (&conversion_obstack, p);
4238 /* If, after the conversion, both operands have class type,
4239 treat the cv-qualification of both operands as if it were the
4240 union of the cv-qualification of the operands.
4242 The standard is not clear about what to do in this
4243 circumstance. For example, if the first operand has type
4244 "const X" and the second operand has a user-defined
4245 conversion to "volatile X", what is the type of the second
4246 operand after this step? Making it be "const X" (matching
4247 the first operand) seems wrong, as that discards the
4248 qualification without actually performing a copy. Leaving it
4249 as "volatile X" seems wrong as that will result in the
4250 conditional expression failing altogether, even though,
4251 according to this step, the one operand could be converted to
4252 the type of the other. */
4253 if ((conv2 || conv3)
4254 && CLASS_TYPE_P (arg2_type)
4255 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
4256 arg2_type = arg3_type =
4257 cp_build_qualified_type (arg2_type,
4258 cp_type_quals (arg2_type)
4259 | cp_type_quals (arg3_type));
4264 If the second and third operands are lvalues and have the same
4265 type, the result is of that type and is an lvalue. */
4266 if (real_lvalue_p (arg2)
4267 && real_lvalue_p (arg3)
4268 && same_type_p (arg2_type, arg3_type))
4270 result_type = arg2_type;
4271 arg2 = mark_lvalue_use (arg2);
4272 arg3 = mark_lvalue_use (arg3);
4273 goto valid_operands;
4278 Otherwise, the result is an rvalue. If the second and third
4279 operand do not have the same type, and either has (possibly
4280 cv-qualified) class type, overload resolution is used to
4281 determine the conversions (if any) to be applied to the operands
4282 (_over.match.oper_, _over.built_). */
4284 if (!same_type_p (arg2_type, arg3_type)
4285 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4291 /* Rearrange the arguments so that add_builtin_candidate only has
4292 to know about two args. In build_builtin_candidate, the
4293 arguments are unscrambled. */
4297 add_builtin_candidates (&candidates,
4300 ansi_opname (COND_EXPR),
4306 If the overload resolution fails, the program is
4308 candidates = splice_viable (candidates, pedantic, &any_viable_p);
4311 if (complain & tf_error)
4313 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4314 print_z_candidates (location_of (arg1), candidates);
4316 return error_mark_node;
4318 cand = tourney (candidates);
4321 if (complain & tf_error)
4323 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4324 print_z_candidates (location_of (arg1), candidates);
4326 return error_mark_node;
4331 Otherwise, the conversions thus determined are applied, and
4332 the converted operands are used in place of the original
4333 operands for the remainder of this section. */
4334 conv = cand->convs[0];
4335 arg1 = convert_like (conv, arg1, complain);
4336 conv = cand->convs[1];
4337 arg2 = convert_like (conv, arg2, complain);
4338 arg2_type = TREE_TYPE (arg2);
4339 conv = cand->convs[2];
4340 arg3 = convert_like (conv, arg3, complain);
4341 arg3_type = TREE_TYPE (arg3);
4346 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
4347 and function-to-pointer (_conv.func_) standard conversions are
4348 performed on the second and third operands.
4350 We need to force the lvalue-to-rvalue conversion here for class types,
4351 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
4352 that isn't wrapped with a TARGET_EXPR plays havoc with exception
4355 arg2 = force_rvalue (arg2);
4356 if (!CLASS_TYPE_P (arg2_type))
4357 arg2_type = TREE_TYPE (arg2);
4359 arg3 = force_rvalue (arg3);
4360 if (!CLASS_TYPE_P (arg3_type))
4361 arg3_type = TREE_TYPE (arg3);
4363 if (arg2 == error_mark_node || arg3 == error_mark_node)
4364 return error_mark_node;
4368 After those conversions, one of the following shall hold:
4370 --The second and third operands have the same type; the result is of
4372 if (same_type_p (arg2_type, arg3_type))
4373 result_type = arg2_type;
4376 --The second and third operands have arithmetic or enumeration
4377 type; the usual arithmetic conversions are performed to bring
4378 them to a common type, and the result is of that type. */
4379 else if ((ARITHMETIC_TYPE_P (arg2_type)
4380 || UNSCOPED_ENUM_P (arg2_type))
4381 && (ARITHMETIC_TYPE_P (arg3_type)
4382 || UNSCOPED_ENUM_P (arg3_type)))
4384 /* In this case, there is always a common type. */
4385 result_type = type_after_usual_arithmetic_conversions (arg2_type,
4387 do_warn_double_promotion (result_type, arg2_type, arg3_type,
4388 "implicit conversion from %qT to %qT to "
4389 "match other result of conditional",
4392 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
4393 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
4395 if (complain & tf_warning)
4397 "enumeral mismatch in conditional expression: %qT vs %qT",
4398 arg2_type, arg3_type);
4400 else if (extra_warnings
4401 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
4402 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
4403 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
4404 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
4406 if (complain & tf_warning)
4408 "enumeral and non-enumeral type in conditional expression");
4411 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4412 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4416 --The second and third operands have pointer type, or one has
4417 pointer type and the other is a null pointer constant; pointer
4418 conversions (_conv.ptr_) and qualification conversions
4419 (_conv.qual_) are performed to bring them to their composite
4420 pointer type (_expr.rel_). The result is of the composite
4423 --The second and third operands have pointer to member type, or
4424 one has pointer to member type and the other is a null pointer
4425 constant; pointer to member conversions (_conv.mem_) and
4426 qualification conversions (_conv.qual_) are performed to bring
4427 them to a common type, whose cv-qualification shall match the
4428 cv-qualification of either the second or the third operand.
4429 The result is of the common type. */
4430 else if ((null_ptr_cst_p (arg2)
4431 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
4432 || (null_ptr_cst_p (arg3)
4433 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
4434 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
4435 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
4436 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
4438 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
4439 arg3, CPO_CONDITIONAL_EXPR,
4441 if (result_type == error_mark_node)
4442 return error_mark_node;
4443 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4444 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4449 if (complain & tf_error)
4450 error ("operands to ?: have different types %qT and %qT",
4451 arg2_type, arg3_type);
4452 return error_mark_node;
4456 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3);
4457 if (!cp_unevaluated_operand)
4458 /* Avoid folding within decltype (c++/42013) and noexcept. */
4459 result = fold_if_not_in_template (result);
4461 /* We can't use result_type below, as fold might have returned a
4466 /* Expand both sides into the same slot, hopefully the target of
4467 the ?: expression. We used to check for TARGET_EXPRs here,
4468 but now we sometimes wrap them in NOP_EXPRs so the test would
4470 if (CLASS_TYPE_P (TREE_TYPE (result)))
4471 result = get_target_expr (result);
4472 /* If this expression is an rvalue, but might be mistaken for an
4473 lvalue, we must add a NON_LVALUE_EXPR. */
4474 result = rvalue (result);
4480 /* OPERAND is an operand to an expression. Perform necessary steps
4481 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4485 prep_operand (tree operand)
4489 if (CLASS_TYPE_P (TREE_TYPE (operand))
4490 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
4491 /* Make sure the template type is instantiated now. */
4492 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
4498 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4499 OVERLOAD) to the CANDIDATES, returning an updated list of
4500 CANDIDATES. The ARGS are the arguments provided to the call;
4501 if FIRST_ARG is non-null it is the implicit object argument,
4502 otherwise the first element of ARGS is used if needed. The
4503 EXPLICIT_TARGS are explicit template arguments provided.
4504 TEMPLATE_ONLY is true if only template functions should be
4505 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4506 add_function_candidate. */
4509 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args,
4511 tree explicit_targs, bool template_only,
4512 tree conversion_path, tree access_path,
4514 struct z_candidate **candidates)
4517 const VEC(tree,gc) *non_static_args;
4518 bool check_list_ctor;
4519 bool check_converting;
4520 unification_kind_t strict;
4526 /* Precalculate special handling of constructors and conversion ops. */
4527 fn = OVL_CURRENT (fns);
4528 if (DECL_CONV_FN_P (fn))
4530 check_list_ctor = false;
4531 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4532 if (flags & LOOKUP_NO_CONVERSION)
4533 /* We're doing return_type(x). */
4534 strict = DEDUCE_CONV;
4536 /* We're doing x.operator return_type(). */
4537 strict = DEDUCE_EXACT;
4538 /* [over.match.funcs] For conversion functions, the function
4539 is considered to be a member of the class of the implicit
4540 object argument for the purpose of defining the type of
4541 the implicit object parameter. */
4542 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg)));
4546 if (DECL_CONSTRUCTOR_P (fn))
4548 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY);
4549 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4553 check_list_ctor = false;
4554 check_converting = false;
4556 strict = DEDUCE_CALL;
4557 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
4561 non_static_args = args;
4563 /* Delay creating the implicit this parameter until it is needed. */
4564 non_static_args = NULL;
4566 for (; fns; fns = OVL_NEXT (fns))
4569 const VEC(tree,gc) *fn_args;
4571 fn = OVL_CURRENT (fns);
4573 if (check_converting && DECL_NONCONVERTING_P (fn))
4575 if (check_list_ctor && !is_list_ctor (fn))
4578 /* Figure out which set of arguments to use. */
4579 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
4581 /* If this function is a non-static member and we didn't get an
4582 implicit object argument, move it out of args. */
4583 if (first_arg == NULL_TREE)
4587 VEC(tree,gc) *tempvec
4588 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1);
4589 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix)
4590 VEC_quick_push (tree, tempvec, arg);
4591 non_static_args = tempvec;
4592 first_arg = build_this (VEC_index (tree, args, 0));
4595 fn_first_arg = first_arg;
4596 fn_args = non_static_args;
4600 /* Otherwise, just use the list of arguments provided. */
4601 fn_first_arg = NULL_TREE;
4605 if (TREE_CODE (fn) == TEMPLATE_DECL)
4606 add_template_candidate (candidates,
4617 else if (!template_only)
4618 add_function_candidate (candidates,
4629 /* Even unsigned enum types promote to signed int. We don't want to
4630 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4631 original argument and ARG is the argument after any conversions
4632 have been applied. We set TREE_NO_WARNING if we have added a cast
4633 from an unsigned enum type to a signed integer type. */
4636 avoid_sign_compare_warnings (tree orig_arg, tree arg)
4638 if (orig_arg != NULL_TREE
4641 && TREE_CODE (TREE_TYPE (orig_arg)) == ENUMERAL_TYPE
4642 && TYPE_UNSIGNED (TREE_TYPE (orig_arg))
4643 && INTEGRAL_TYPE_P (TREE_TYPE (arg))
4644 && !TYPE_UNSIGNED (TREE_TYPE (arg)))
4645 TREE_NO_WARNING (arg) = 1;
4649 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
4650 bool *overloaded_p, tsubst_flags_t complain)
4652 tree orig_arg1 = arg1;
4653 tree orig_arg2 = arg2;
4654 tree orig_arg3 = arg3;
4655 struct z_candidate *candidates = 0, *cand;
4656 VEC(tree,gc) *arglist;
4659 tree result = NULL_TREE;
4660 bool result_valid_p = false;
4661 enum tree_code code2 = NOP_EXPR;
4662 enum tree_code code_orig_arg1 = ERROR_MARK;
4663 enum tree_code code_orig_arg2 = ERROR_MARK;
4669 if (error_operand_p (arg1)
4670 || error_operand_p (arg2)
4671 || error_operand_p (arg3))
4672 return error_mark_node;
4674 if (code == MODIFY_EXPR)
4676 code2 = TREE_CODE (arg3);
4678 fnname = ansi_assopname (code2);
4681 fnname = ansi_opname (code);
4683 arg1 = prep_operand (arg1);
4689 case VEC_DELETE_EXPR:
4691 /* Use build_op_new_call and build_op_delete_call instead. */
4695 /* Use build_op_call instead. */
4698 case TRUTH_ORIF_EXPR:
4699 case TRUTH_ANDIF_EXPR:
4700 case TRUTH_AND_EXPR:
4702 /* These are saved for the sake of warn_logical_operator. */
4703 code_orig_arg1 = TREE_CODE (arg1);
4704 code_orig_arg2 = TREE_CODE (arg2);
4710 arg2 = prep_operand (arg2);
4711 arg3 = prep_operand (arg3);
4713 if (code == COND_EXPR)
4714 /* Use build_conditional_expr instead. */
4716 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
4717 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4720 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4721 arg2 = integer_zero_node;
4723 arglist = VEC_alloc (tree, gc, 3);
4724 VEC_quick_push (tree, arglist, arg1);
4725 if (arg2 != NULL_TREE)
4726 VEC_quick_push (tree, arglist, arg2);
4727 if (arg3 != NULL_TREE)
4728 VEC_quick_push (tree, arglist, arg3);
4730 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4731 p = conversion_obstack_alloc (0);
4733 /* Add namespace-scope operators to the list of functions to
4735 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4736 NULL_TREE, arglist, NULL_TREE,
4737 NULL_TREE, false, NULL_TREE, NULL_TREE,
4738 flags, &candidates);
4739 /* Add class-member operators to the candidate set. */
4740 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4744 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4745 if (fns == error_mark_node)
4747 result = error_mark_node;
4748 goto user_defined_result_ready;
4751 add_candidates (BASELINK_FUNCTIONS (fns),
4752 NULL_TREE, arglist, NULL_TREE,
4754 BASELINK_BINFO (fns),
4755 BASELINK_ACCESS_BINFO (fns),
4756 flags, &candidates);
4761 args[2] = NULL_TREE;
4763 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4769 /* For these, the built-in candidates set is empty
4770 [over.match.oper]/3. We don't want non-strict matches
4771 because exact matches are always possible with built-in
4772 operators. The built-in candidate set for COMPONENT_REF
4773 would be empty too, but since there are no such built-in
4774 operators, we accept non-strict matches for them. */
4779 strict_p = pedantic;
4783 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4788 case POSTINCREMENT_EXPR:
4789 case POSTDECREMENT_EXPR:
4790 /* Don't try anything fancy if we're not allowed to produce
4792 if (!(complain & tf_error))
4793 return error_mark_node;
4795 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4796 distinguish between prefix and postfix ++ and
4797 operator++() was used for both, so we allow this with
4799 if (flags & LOOKUP_COMPLAIN)
4801 const char *msg = (flag_permissive)
4802 ? G_("no %<%D(int)%> declared for postfix %qs,"
4803 " trying prefix operator instead")
4804 : G_("no %<%D(int)%> declared for postfix %qs");
4805 permerror (input_location, msg, fnname,
4806 operator_name_info[code].name);
4809 if (!flag_permissive)
4810 return error_mark_node;
4812 if (code == POSTINCREMENT_EXPR)
4813 code = PREINCREMENT_EXPR;
4815 code = PREDECREMENT_EXPR;
4816 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
4817 overloaded_p, complain);
4820 /* The caller will deal with these. */
4825 result_valid_p = true;
4829 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4831 /* If one of the arguments of the operator represents
4832 an invalid use of member function pointer, try to report
4833 a meaningful error ... */
4834 if (invalid_nonstatic_memfn_p (arg1, tf_error)
4835 || invalid_nonstatic_memfn_p (arg2, tf_error)
4836 || invalid_nonstatic_memfn_p (arg3, tf_error))
4837 /* We displayed the error message. */;
4840 /* ... Otherwise, report the more generic
4841 "no matching operator found" error */
4842 op_error (code, code2, arg1, arg2, arg3, FALSE);
4843 print_z_candidates (input_location, candidates);
4846 result = error_mark_node;
4852 cand = tourney (candidates);
4855 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4857 op_error (code, code2, arg1, arg2, arg3, TRUE);
4858 print_z_candidates (input_location, candidates);
4860 result = error_mark_node;
4862 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4865 *overloaded_p = true;
4867 if (resolve_args (arglist) == NULL)
4868 result = error_mark_node;
4870 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4874 /* Give any warnings we noticed during overload resolution. */
4875 if (cand->warnings && (complain & tf_warning))
4877 struct candidate_warning *w;
4878 for (w = cand->warnings; w; w = w->next)
4879 joust (cand, w->loser, 1);
4882 /* Check for comparison of different enum types. */
4891 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
4892 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
4893 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
4894 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
4895 && (complain & tf_warning))
4897 warning (OPT_Wenum_compare,
4898 "comparison between %q#T and %q#T",
4899 TREE_TYPE (arg1), TREE_TYPE (arg2));
4906 /* We need to strip any leading REF_BIND so that bitfields
4907 don't cause errors. This should not remove any important
4908 conversions, because builtins don't apply to class
4909 objects directly. */
4910 conv = cand->convs[0];
4911 if (conv->kind == ck_ref_bind)
4912 conv = conv->u.next;
4913 arg1 = convert_like (conv, arg1, complain);
4917 /* We need to call warn_logical_operator before
4918 converting arg2 to a boolean_type. */
4919 if (complain & tf_warning)
4920 warn_logical_operator (input_location, code, boolean_type_node,
4921 code_orig_arg1, arg1,
4922 code_orig_arg2, arg2);
4924 conv = cand->convs[1];
4925 if (conv->kind == ck_ref_bind)
4926 conv = conv->u.next;
4927 arg2 = convert_like (conv, arg2, complain);
4931 conv = cand->convs[2];
4932 if (conv->kind == ck_ref_bind)
4933 conv = conv->u.next;
4934 arg3 = convert_like (conv, arg3, complain);
4940 user_defined_result_ready:
4942 /* Free all the conversions we allocated. */
4943 obstack_free (&conversion_obstack, p);
4945 if (result || result_valid_p)
4949 avoid_sign_compare_warnings (orig_arg1, arg1);
4950 avoid_sign_compare_warnings (orig_arg2, arg2);
4951 avoid_sign_compare_warnings (orig_arg3, arg3);
4956 return cp_build_modify_expr (arg1, code2, arg2, complain);
4959 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
4961 case TRUTH_ANDIF_EXPR:
4962 case TRUTH_ORIF_EXPR:
4963 case TRUTH_AND_EXPR:
4965 warn_logical_operator (input_location, code, boolean_type_node,
4966 code_orig_arg1, arg1, code_orig_arg2, arg2);
4971 case TRUNC_DIV_EXPR:
4982 case TRUNC_MOD_EXPR:
4986 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
4988 case UNARY_PLUS_EXPR:
4991 case TRUTH_NOT_EXPR:
4992 case PREINCREMENT_EXPR:
4993 case POSTINCREMENT_EXPR:
4994 case PREDECREMENT_EXPR:
4995 case POSTDECREMENT_EXPR:
4998 return cp_build_unary_op (code, arg1, candidates != 0, complain);
5001 return cp_build_array_ref (input_location, arg1, arg2, complain);
5004 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL,
5008 /* The caller will deal with these. */
5020 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
5021 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
5024 non_placement_deallocation_fn_p (tree t)
5026 /* A template instance is never a usual deallocation function,
5027 regardless of its signature. */
5028 if (TREE_CODE (t) == TEMPLATE_DECL
5029 || primary_template_instantiation_p (t))
5032 /* If a class T has a member deallocation function named operator delete
5033 with exactly one parameter, then that function is a usual
5034 (non-placement) deallocation function. If class T does not declare
5035 such an operator delete but does declare a member deallocation
5036 function named operator delete with exactly two parameters, the second
5037 of which has type std::size_t (18.2), then this function is a usual
5038 deallocation function. */
5039 t = FUNCTION_ARG_CHAIN (t);
5040 if (t == void_list_node
5041 || (t && same_type_p (TREE_VALUE (t), size_type_node)
5042 && TREE_CHAIN (t) == void_list_node))
5047 /* Build a call to operator delete. This has to be handled very specially,
5048 because the restrictions on what signatures match are different from all
5049 other call instances. For a normal delete, only a delete taking (void *)
5050 or (void *, size_t) is accepted. For a placement delete, only an exact
5051 match with the placement new is accepted.
5053 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
5054 ADDR is the pointer to be deleted.
5055 SIZE is the size of the memory block to be deleted.
5056 GLOBAL_P is true if the delete-expression should not consider
5057 class-specific delete operators.
5058 PLACEMENT is the corresponding placement new call, or NULL_TREE.
5060 If this call to "operator delete" is being generated as part to
5061 deallocate memory allocated via a new-expression (as per [expr.new]
5062 which requires that if the initialization throws an exception then
5063 we call a deallocation function), then ALLOC_FN is the allocation
5067 build_op_delete_call (enum tree_code code, tree addr, tree size,
5068 bool global_p, tree placement,
5071 tree fn = NULL_TREE;
5072 tree fns, fnname, type, t;
5074 if (addr == error_mark_node)
5075 return error_mark_node;
5077 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
5079 fnname = ansi_opname (code);
5081 if (CLASS_TYPE_P (type)
5082 && COMPLETE_TYPE_P (complete_type (type))
5086 If the result of the lookup is ambiguous or inaccessible, or if
5087 the lookup selects a placement deallocation function, the
5088 program is ill-formed.
5090 Therefore, we ask lookup_fnfields to complain about ambiguity. */
5092 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
5093 if (fns == error_mark_node)
5094 return error_mark_node;
5099 if (fns == NULL_TREE)
5100 fns = lookup_name_nonclass (fnname);
5102 /* Strip const and volatile from addr. */
5103 addr = cp_convert (ptr_type_node, addr);
5107 /* "A declaration of a placement deallocation function matches the
5108 declaration of a placement allocation function if it has the same
5109 number of parameters and, after parameter transformations (8.3.5),
5110 all parameter types except the first are identical."
5112 So we build up the function type we want and ask instantiate_type
5113 to get it for us. */
5114 t = FUNCTION_ARG_CHAIN (alloc_fn);
5115 t = tree_cons (NULL_TREE, ptr_type_node, t);
5116 t = build_function_type (void_type_node, t);
5118 fn = instantiate_type (t, fns, tf_none);
5119 if (fn == error_mark_node)
5122 if (BASELINK_P (fn))
5123 fn = BASELINK_FUNCTIONS (fn);
5125 /* "If the lookup finds the two-parameter form of a usual deallocation
5126 function (3.7.4.2) and that function, considered as a placement
5127 deallocation function, would have been selected as a match for the
5128 allocation function, the program is ill-formed." */
5129 if (non_placement_deallocation_fn_p (fn))
5131 /* But if the class has an operator delete (void *), then that is
5132 the usual deallocation function, so we shouldn't complain
5133 about using the operator delete (void *, size_t). */
5134 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5135 t; t = OVL_NEXT (t))
5137 tree elt = OVL_CURRENT (t);
5138 if (non_placement_deallocation_fn_p (elt)
5139 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
5142 permerror (0, "non-placement deallocation function %q+D", fn);
5143 permerror (input_location, "selected for placement delete");
5148 /* "Any non-placement deallocation function matches a non-placement
5149 allocation function. If the lookup finds a single matching
5150 deallocation function, that function will be called; otherwise, no
5151 deallocation function will be called." */
5152 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5153 t; t = OVL_NEXT (t))
5155 tree elt = OVL_CURRENT (t);
5156 if (non_placement_deallocation_fn_p (elt))
5159 /* "If a class T has a member deallocation function named
5160 operator delete with exactly one parameter, then that
5161 function is a usual (non-placement) deallocation
5162 function. If class T does not declare such an operator
5163 delete but does declare a member deallocation function named
5164 operator delete with exactly two parameters, the second of
5165 which has type std::size_t (18.2), then this function is a
5166 usual deallocation function."
5168 So (void*) beats (void*, size_t). */
5169 if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
5174 /* If we have a matching function, call it. */
5177 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5179 /* If the FN is a member function, make sure that it is
5181 if (BASELINK_P (fns))
5182 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn);
5184 /* Core issue 901: It's ok to new a type with deleted delete. */
5185 if (DECL_DELETED_FN (fn) && alloc_fn)
5190 /* The placement args might not be suitable for overload
5191 resolution at this point, so build the call directly. */
5192 int nargs = call_expr_nargs (placement);
5193 tree *argarray = XALLOCAVEC (tree, nargs);
5196 for (i = 1; i < nargs; i++)
5197 argarray[i] = CALL_EXPR_ARG (placement, i);
5199 return build_cxx_call (fn, nargs, argarray);
5204 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2);
5205 VEC_quick_push (tree, args, addr);
5206 if (FUNCTION_ARG_CHAIN (fn) != void_list_node)
5207 VEC_quick_push (tree, args, size);
5208 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error);
5209 VEC_free (tree, gc, args);
5216 If no unambiguous matching deallocation function can be found,
5217 propagating the exception does not cause the object's memory to
5222 warning (0, "no corresponding deallocation function for %qD",
5227 error ("no suitable %<operator %s%> for %qT",
5228 operator_name_info[(int)code].name, type);
5229 return error_mark_node;
5232 /* If the current scope isn't allowed to access DECL along
5233 BASETYPE_PATH, give an error. The most derived class in
5234 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
5235 the declaration to use in the error diagnostic. */
5238 enforce_access (tree basetype_path, tree decl, tree diag_decl)
5240 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
5242 if (!accessible_p (basetype_path, decl, true))
5244 if (TREE_PRIVATE (decl))
5245 error ("%q+#D is private", diag_decl);
5246 else if (TREE_PROTECTED (decl))
5247 error ("%q+#D is protected", diag_decl);
5249 error ("%q+#D is inaccessible", diag_decl);
5250 error ("within this context");
5257 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
5258 bitwise or of LOOKUP_* values. If any errors are warnings are
5259 generated, set *DIAGNOSTIC_FN to "error" or "warning",
5260 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
5264 build_temp (tree expr, tree type, int flags,
5265 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
5270 savew = warningcount, savee = errorcount;
5271 args = make_tree_vector_single (expr);
5272 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
5273 &args, type, flags, complain);
5274 release_tree_vector (args);
5275 if (warningcount > savew)
5276 *diagnostic_kind = DK_WARNING;
5277 else if (errorcount > savee)
5278 *diagnostic_kind = DK_ERROR;
5280 *diagnostic_kind = DK_UNSPECIFIED;
5284 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
5285 EXPR is implicitly converted to type TOTYPE.
5286 FN and ARGNUM are used for diagnostics. */
5289 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
5291 tree t = non_reference (totype);
5293 /* Issue warnings about peculiar, but valid, uses of NULL. */
5294 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
5297 warning_at (input_location, OPT_Wconversion_null,
5298 "passing NULL to non-pointer argument %P of %qD",
5301 warning_at (input_location, OPT_Wconversion_null,
5302 "converting to non-pointer type %qT from NULL", t);
5305 /* Issue warnings if "false" is converted to a NULL pointer */
5306 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
5307 warning_at (input_location, OPT_Wconversion_null,
5308 "converting %<false%> to pointer type for argument %P of %qD",
5312 /* Perform the conversions in CONVS on the expression EXPR. FN and
5313 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
5314 indicates the `this' argument of a method. INNER is nonzero when
5315 being called to continue a conversion chain. It is negative when a
5316 reference binding will be applied, positive otherwise. If
5317 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
5318 conversions will be emitted if appropriate. If C_CAST_P is true,
5319 this conversion is coming from a C-style cast; in that case,
5320 conversions to inaccessible bases are permitted. */
5323 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
5324 int inner, bool issue_conversion_warnings,
5325 bool c_cast_p, tsubst_flags_t complain)
5327 tree totype = convs->type;
5328 diagnostic_t diag_kind;
5332 && convs->kind != ck_user
5333 && convs->kind != ck_list
5334 && convs->kind != ck_ambig
5335 && convs->kind != ck_ref_bind
5336 && convs->kind != ck_rvalue
5337 && convs->kind != ck_base)
5339 conversion *t = convs;
5341 /* Give a helpful error if this is bad because of excess braces. */
5342 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
5343 && SCALAR_TYPE_P (totype)
5344 && CONSTRUCTOR_NELTS (expr) > 0
5345 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
5346 permerror (input_location, "too many braces around initializer for %qT", totype);
5348 for (; t; t = convs->u.next)
5350 if (t->kind == ck_user || !t->bad_p)
5352 expr = convert_like_real (t, expr, fn, argnum, 1,
5353 /*issue_conversion_warnings=*/false,
5358 else if (t->kind == ck_ambig)
5359 return convert_like_real (t, expr, fn, argnum, 1,
5360 /*issue_conversion_warnings=*/false,
5363 else if (t->kind == ck_identity)
5366 if (complain & tf_error)
5368 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
5370 permerror (DECL_SOURCE_LOCATION (fn),
5371 " initializing argument %P of %qD", argnum, fn);
5374 return error_mark_node;
5376 return cp_convert (totype, expr);
5379 if (issue_conversion_warnings && (complain & tf_warning))
5380 conversion_null_warnings (totype, expr, fn, argnum);
5382 switch (convs->kind)
5386 struct z_candidate *cand = convs->cand;
5387 tree convfn = cand->fn;
5390 expr = mark_rvalue_use (expr);
5392 /* When converting from an init list we consider explicit
5393 constructors, but actually trying to call one is an error. */
5394 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
5395 /* Unless we're calling it for value-initialization from an
5396 empty list, since that is handled separately in 8.5.4. */
5397 && cand->num_convs > 0)
5399 if (complain & tf_error)
5400 error ("converting to %qT from initializer list would use "
5401 "explicit constructor %qD", totype, convfn);
5403 return error_mark_node;
5406 /* Set user_conv_p on the argument conversions, so rvalue/base
5407 handling knows not to allow any more UDCs. */
5408 for (i = 0; i < cand->num_convs; ++i)
5409 cand->convs[i]->user_conv_p = true;
5411 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
5413 /* If this is a constructor or a function returning an aggr type,
5414 we need to build up a TARGET_EXPR. */
5415 if (DECL_CONSTRUCTOR_P (convfn))
5417 expr = build_cplus_new (totype, expr);
5419 /* Remember that this was list-initialization. */
5420 if (convs->check_narrowing)
5421 TARGET_EXPR_LIST_INIT_P (expr) = true;
5427 expr = mark_rvalue_use (expr);
5428 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
5430 int nelts = CONSTRUCTOR_NELTS (expr);
5432 expr = build_value_init (totype, tf_warning_or_error);
5433 else if (nelts == 1)
5434 expr = CONSTRUCTOR_ELT (expr, 0)->value;
5439 if (type_unknown_p (expr))
5440 expr = instantiate_type (totype, expr, complain);
5441 /* Convert a constant to its underlying value, unless we are
5442 about to bind it to a reference, in which case we need to
5443 leave it as an lvalue. */
5446 expr = decl_constant_value (expr);
5447 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
5448 /* If __null has been converted to an integer type, we do not
5449 want to warn about uses of EXPR as an integer, rather than
5451 expr = build_int_cst (totype, 0);
5455 if (complain & tf_error)
5457 /* Call build_user_type_conversion again for the error. */
5458 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL);
5460 error (" initializing argument %P of %q+D", argnum, fn);
5462 return error_mark_node;
5466 /* Conversion to std::initializer_list<T>. */
5467 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
5468 tree new_ctor = build_constructor (init_list_type_node, NULL);
5469 unsigned len = CONSTRUCTOR_NELTS (expr);
5470 tree array, val, field;
5471 VEC(constructor_elt,gc) *vec = NULL;
5474 /* Convert all the elements. */
5475 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
5477 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
5478 1, false, false, complain);
5479 if (sub == error_mark_node)
5481 if (!BRACE_ENCLOSED_INITIALIZER_P (val))
5482 check_narrowing (TREE_TYPE (sub), val);
5483 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
5484 if (!TREE_CONSTANT (sub))
5485 TREE_CONSTANT (new_ctor) = false;
5487 /* Build up the array. */
5488 elttype = cp_build_qualified_type
5489 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
5490 array = build_array_of_n_type (elttype, len);
5491 array = finish_compound_literal (array, new_ctor);
5493 /* Build up the initializer_list object. */
5494 totype = complete_type (totype);
5495 field = next_initializable_field (TYPE_FIELDS (totype));
5496 CONSTRUCTOR_APPEND_ELT (vec, field, decay_conversion (array));
5497 field = next_initializable_field (DECL_CHAIN (field));
5498 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
5499 new_ctor = build_constructor (totype, vec);
5500 return get_target_expr (new_ctor);
5504 return get_target_expr (digest_init (totype, expr));
5510 expr = convert_like_real (convs->u.next, expr, fn, argnum,
5511 convs->kind == ck_ref_bind ? -1 : 1,
5512 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
5515 if (expr == error_mark_node)
5516 return error_mark_node;
5518 switch (convs->kind)
5521 expr = decay_conversion (expr);
5522 if (! MAYBE_CLASS_TYPE_P (totype))
5524 /* Else fall through. */
5526 if (convs->kind == ck_base && !convs->need_temporary_p)
5528 /* We are going to bind a reference directly to a base-class
5529 subobject of EXPR. */
5530 /* Build an expression for `*((base*) &expr)'. */
5531 expr = cp_build_addr_expr (expr, complain);
5532 expr = convert_to_base (expr, build_pointer_type (totype),
5533 !c_cast_p, /*nonnull=*/true, complain);
5534 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain);
5538 /* Copy-initialization where the cv-unqualified version of the source
5539 type is the same class as, or a derived class of, the class of the
5540 destination [is treated as direct-initialization]. [dcl.init] */
5541 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
5542 if (convs->user_conv_p)
5543 /* This conversion is being done in the context of a user-defined
5544 conversion (i.e. the second step of copy-initialization), so
5545 don't allow any more. */
5546 flags |= LOOKUP_NO_CONVERSION;
5547 if (convs->rvaluedness_matches_p)
5548 flags |= LOOKUP_PREFER_RVALUE;
5549 if (TREE_CODE (expr) == TARGET_EXPR
5550 && TARGET_EXPR_LIST_INIT_P (expr))
5551 /* Copy-list-initialization doesn't actually involve a copy. */
5553 expr = build_temp (expr, totype, flags, &diag_kind, complain);
5554 if (diag_kind && fn)
5556 if ((complain & tf_error))
5557 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0,
5558 " initializing argument %P of %qD", argnum, fn);
5559 else if (diag_kind == DK_ERROR)
5560 return error_mark_node;
5562 return build_cplus_new (totype, expr);
5566 tree ref_type = totype;
5568 if (convs->bad_p && TYPE_REF_IS_RVALUE (ref_type)
5569 && real_lvalue_p (expr))
5571 if (complain & tf_error)
5573 error ("cannot bind %qT lvalue to %qT",
5574 TREE_TYPE (expr), totype);
5576 error (" initializing argument %P of %q+D", argnum, fn);
5578 return error_mark_node;
5581 /* If necessary, create a temporary.
5583 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5584 that need temporaries, even when their types are reference
5585 compatible with the type of reference being bound, so the
5586 upcoming call to cp_build_addr_expr doesn't fail. */
5587 if (convs->need_temporary_p
5588 || TREE_CODE (expr) == CONSTRUCTOR
5589 || TREE_CODE (expr) == VA_ARG_EXPR)
5591 /* Otherwise, a temporary of type "cv1 T1" is created and
5592 initialized from the initializer expression using the rules
5593 for a non-reference copy-initialization (8.5). */
5595 tree type = TREE_TYPE (ref_type);
5596 cp_lvalue_kind lvalue = real_lvalue_p (expr);
5598 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5599 (type, convs->u.next->type));
5600 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
5601 && !TYPE_REF_IS_RVALUE (ref_type))
5603 if (complain & tf_error)
5605 /* If the reference is volatile or non-const, we
5606 cannot create a temporary. */
5607 if (lvalue & clk_bitfield)
5608 error ("cannot bind bitfield %qE to %qT",
5610 else if (lvalue & clk_packed)
5611 error ("cannot bind packed field %qE to %qT",
5614 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
5616 return error_mark_node;
5618 /* If the source is a packed field, and we must use a copy
5619 constructor, then building the target expr will require
5620 binding the field to the reference parameter to the
5621 copy constructor, and we'll end up with an infinite
5622 loop. If we can use a bitwise copy, then we'll be
5624 if ((lvalue & clk_packed)
5625 && CLASS_TYPE_P (type)
5626 && type_has_nontrivial_copy_init (type))
5628 if (complain & tf_error)
5629 error ("cannot bind packed field %qE to %qT",
5631 return error_mark_node;
5633 if (lvalue & clk_bitfield)
5635 expr = convert_bitfield_to_declared_type (expr);
5636 expr = fold_convert (type, expr);
5638 expr = build_target_expr_with_type (expr, type);
5641 /* Take the address of the thing to which we will bind the
5643 expr = cp_build_addr_expr (expr, complain);
5644 if (expr == error_mark_node)
5645 return error_mark_node;
5647 /* Convert it to a pointer to the type referred to by the
5648 reference. This will adjust the pointer if a derived to
5649 base conversion is being performed. */
5650 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
5652 /* Convert the pointer to the desired reference type. */
5653 return build_nop (ref_type, expr);
5657 return decay_conversion (expr);
5660 /* Warn about deprecated conversion if appropriate. */
5661 string_conv_p (totype, expr, 1);
5666 expr = convert_to_base (expr, totype, !c_cast_p,
5667 /*nonnull=*/false, complain);
5668 return build_nop (totype, expr);
5671 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
5672 c_cast_p, complain);
5678 if (convs->check_narrowing)
5679 check_narrowing (totype, expr);
5681 if (issue_conversion_warnings && (complain & tf_warning))
5682 expr = convert_and_check (totype, expr);
5684 expr = convert (totype, expr);
5689 /* ARG is being passed to a varargs function. Perform any conversions
5690 required. Return the converted value. */
5693 convert_arg_to_ellipsis (tree arg)
5699 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5700 standard conversions are performed. */
5701 arg = decay_conversion (arg);
5702 arg_type = TREE_TYPE (arg);
5705 If the argument has integral or enumeration type that is subject
5706 to the integral promotions (_conv.prom_), or a floating point
5707 type that is subject to the floating point promotion
5708 (_conv.fpprom_), the value of the argument is converted to the
5709 promoted type before the call. */
5710 if (TREE_CODE (arg_type) == REAL_TYPE
5711 && (TYPE_PRECISION (arg_type)
5712 < TYPE_PRECISION (double_type_node))
5713 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
5715 if (warn_double_promotion && !c_inhibit_evaluation_warnings)
5716 warning (OPT_Wdouble_promotion,
5717 "implicit conversion from %qT to %qT when passing "
5718 "argument to function",
5719 arg_type, double_type_node);
5720 arg = convert_to_real (double_type_node, arg);
5722 else if (NULLPTR_TYPE_P (arg_type))
5723 arg = null_pointer_node;
5724 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
5725 arg = perform_integral_promotions (arg);
5727 arg = require_complete_type (arg);
5728 arg_type = TREE_TYPE (arg);
5730 if (arg != error_mark_node
5731 /* In a template (or ill-formed code), we can have an incomplete type
5732 even after require_complete_type, in which case we don't know
5733 whether it has trivial copy or not. */
5734 && COMPLETE_TYPE_P (arg_type)
5735 && (type_has_nontrivial_copy_init (arg_type)
5736 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
5738 /* [expr.call] 5.2.2/7:
5739 Passing a potentially-evaluated argument of class type (Clause 9)
5740 with a non-trivial copy constructor or a non-trivial destructor
5741 with no corresponding parameter is conditionally-supported, with
5742 implementation-defined semantics.
5744 We used to just warn here and do a bitwise copy, but now
5745 cp_expr_size will abort if we try to do that.
5747 If the call appears in the context of a sizeof expression,
5748 it is not potentially-evaluated. */
5749 if (cp_unevaluated_operand == 0)
5750 error ("cannot pass objects of non-trivially-copyable "
5751 "type %q#T through %<...%>", arg_type);
5757 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5760 build_x_va_arg (tree expr, tree type)
5762 if (processing_template_decl)
5763 return build_min (VA_ARG_EXPR, type, expr);
5765 type = complete_type_or_else (type, NULL_TREE);
5767 if (expr == error_mark_node || !type)
5768 return error_mark_node;
5770 expr = mark_lvalue_use (expr);
5772 if (type_has_nontrivial_copy_init (type)
5773 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
5774 || TREE_CODE (type) == REFERENCE_TYPE)
5776 /* Remove reference types so we don't ICE later on. */
5777 tree type1 = non_reference (type);
5778 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5779 error ("cannot receive objects of non-trivially-copyable type %q#T "
5780 "through %<...%>; ", type);
5781 expr = convert (build_pointer_type (type1), null_node);
5782 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error);
5786 return build_va_arg (input_location, expr, type);
5789 /* TYPE has been given to va_arg. Apply the default conversions which
5790 would have happened when passed via ellipsis. Return the promoted
5791 type, or the passed type if there is no change. */
5794 cxx_type_promotes_to (tree type)
5798 /* Perform the array-to-pointer and function-to-pointer
5800 type = type_decays_to (type);
5802 promote = type_promotes_to (type);
5803 if (same_type_p (type, promote))
5809 /* ARG is a default argument expression being passed to a parameter of
5810 the indicated TYPE, which is a parameter to FN. PARMNUM is the
5811 zero-based argument number. Do any required conversions. Return
5812 the converted value. */
5814 static GTY(()) VEC(tree,gc) *default_arg_context;
5816 push_defarg_context (tree fn)
5817 { VEC_safe_push (tree, gc, default_arg_context, fn); }
5819 pop_defarg_context (void)
5820 { VEC_pop (tree, default_arg_context); }
5823 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
5828 /* See through clones. */
5829 fn = DECL_ORIGIN (fn);
5831 /* Detect recursion. */
5832 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t)
5835 error ("recursive evaluation of default argument for %q#D", fn);
5836 return error_mark_node;
5839 /* If the ARG is an unparsed default argument expression, the
5840 conversion cannot be performed. */
5841 if (TREE_CODE (arg) == DEFAULT_ARG)
5843 error ("call to %qD uses the default argument for parameter %P, which "
5844 "is not yet defined", fn, parmnum);
5845 return error_mark_node;
5848 push_defarg_context (fn);
5850 if (fn && DECL_TEMPLATE_INFO (fn))
5851 arg = tsubst_default_argument (fn, type, arg);
5857 The names in the expression are bound, and the semantic
5858 constraints are checked, at the point where the default
5859 expressions appears.
5861 we must not perform access checks here. */
5862 push_deferring_access_checks (dk_no_check);
5863 arg = break_out_target_exprs (arg);
5864 if (TREE_CODE (arg) == CONSTRUCTOR)
5866 arg = digest_init (type, arg);
5867 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5868 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5869 tf_warning_or_error);
5873 /* We must make a copy of ARG, in case subsequent processing
5874 alters any part of it. For example, during gimplification a
5875 cast of the form (T) &X::f (where "f" is a member function)
5876 will lead to replacing the PTRMEM_CST for &X::f with a
5877 VAR_DECL. We can avoid the copy for constants, since they
5878 are never modified in place. */
5879 if (!CONSTANT_CLASS_P (arg))
5880 arg = unshare_expr (arg);
5881 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5882 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5883 tf_warning_or_error);
5884 arg = convert_for_arg_passing (type, arg);
5886 pop_deferring_access_checks();
5888 pop_defarg_context ();
5893 /* Returns the type which will really be used for passing an argument of
5897 type_passed_as (tree type)
5899 /* Pass classes with copy ctors by invisible reference. */
5900 if (TREE_ADDRESSABLE (type))
5902 type = build_reference_type (type);
5903 /* There are no other pointers to this temporary. */
5904 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
5906 else if (targetm.calls.promote_prototypes (type)
5907 && INTEGRAL_TYPE_P (type)
5908 && COMPLETE_TYPE_P (type)
5909 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5910 TYPE_SIZE (integer_type_node)))
5911 type = integer_type_node;
5916 /* Actually perform the appropriate conversion. */
5919 convert_for_arg_passing (tree type, tree val)
5923 /* If VAL is a bitfield, then -- since it has already been converted
5924 to TYPE -- it cannot have a precision greater than TYPE.
5926 If it has a smaller precision, we must widen it here. For
5927 example, passing "int f:3;" to a function expecting an "int" will
5928 not result in any conversion before this point.
5930 If the precision is the same we must not risk widening. For
5931 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5932 often have type "int", even though the C++ type for the field is
5933 "long long". If the value is being passed to a function
5934 expecting an "int", then no conversions will be required. But,
5935 if we call convert_bitfield_to_declared_type, the bitfield will
5936 be converted to "long long". */
5937 bitfield_type = is_bitfield_expr_with_lowered_type (val);
5939 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
5940 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
5942 if (val == error_mark_node)
5944 /* Pass classes with copy ctors by invisible reference. */
5945 else if (TREE_ADDRESSABLE (type))
5946 val = build1 (ADDR_EXPR, build_reference_type (type), val);
5947 else if (targetm.calls.promote_prototypes (type)
5948 && INTEGRAL_TYPE_P (type)
5949 && COMPLETE_TYPE_P (type)
5950 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5951 TYPE_SIZE (integer_type_node)))
5952 val = perform_integral_promotions (val);
5953 if (warn_missing_format_attribute)
5955 tree rhstype = TREE_TYPE (val);
5956 const enum tree_code coder = TREE_CODE (rhstype);
5957 const enum tree_code codel = TREE_CODE (type);
5958 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5960 && check_missing_format_attribute (type, rhstype))
5961 warning (OPT_Wmissing_format_attribute,
5962 "argument of function call might be a candidate for a format attribute");
5967 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5968 which no conversions at all should be done. This is true for some
5969 builtins which don't act like normal functions. */
5972 magic_varargs_p (tree fn)
5974 if (DECL_BUILT_IN (fn))
5975 switch (DECL_FUNCTION_CODE (fn))
5977 case BUILT_IN_CLASSIFY_TYPE:
5978 case BUILT_IN_CONSTANT_P:
5979 case BUILT_IN_NEXT_ARG:
5980 case BUILT_IN_VA_START:
5984 return lookup_attribute ("type generic",
5985 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
5991 /* Subroutine of the various build_*_call functions. Overload resolution
5992 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
5993 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
5994 bitmask of various LOOKUP_* flags which apply to the call itself. */
5997 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
6000 const VEC(tree,gc) *args = cand->args;
6001 tree first_arg = cand->first_arg;
6002 conversion **convs = cand->convs;
6004 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
6009 unsigned int arg_index = 0;
6013 bool already_used = false;
6015 /* In a template, there is no need to perform all of the work that
6016 is normally done. We are only interested in the type of the call
6017 expression, i.e., the return type of the function. Any semantic
6018 errors will be deferred until the template is instantiated. */
6019 if (processing_template_decl)
6023 const tree *argarray;
6026 return_type = TREE_TYPE (TREE_TYPE (fn));
6027 nargs = VEC_length (tree, args);
6028 if (first_arg == NULL_TREE)
6029 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args));
6037 alcarray = XALLOCAVEC (tree, nargs);
6038 alcarray[0] = first_arg;
6039 FOR_EACH_VEC_ELT (tree, args, ix, arg)
6040 alcarray[ix + 1] = arg;
6041 argarray = alcarray;
6043 expr = build_call_array_loc (input_location,
6044 return_type, build_addr_func (fn), nargs,
6046 if (TREE_THIS_VOLATILE (fn) && cfun)
6047 current_function_returns_abnormally = 1;
6048 return convert_from_reference (expr);
6051 /* Give any warnings we noticed during overload resolution. */
6052 if (cand->warnings && (complain & tf_warning))
6054 struct candidate_warning *w;
6055 for (w = cand->warnings; w; w = w->next)
6056 joust (cand, w->loser, 1);
6059 /* Make =delete work with SFINAE. */
6060 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
6061 return error_mark_node;
6063 if (DECL_FUNCTION_MEMBER_P (fn))
6066 /* If FN is a template function, two cases must be considered.
6071 template <class T> void f();
6073 template <class T> struct B {
6077 struct C : A, B<int> {
6079 using B<int>::g; // #2
6082 In case #1 where `A::f' is a member template, DECL_ACCESS is
6083 recorded in the primary template but not in its specialization.
6084 We check access of FN using its primary template.
6086 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
6087 because it is a member of class template B, DECL_ACCESS is
6088 recorded in the specialization `B<int>::g'. We cannot use its
6089 primary template because `B<T>::g' and `B<int>::g' may have
6090 different access. */
6091 if (DECL_TEMPLATE_INFO (fn)
6092 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
6093 access_fn = DECL_TI_TEMPLATE (fn);
6096 if (flags & LOOKUP_SPECULATIVE)
6098 if (!speculative_access_check (cand->access_path, access_fn, fn,
6099 !!(flags & LOOKUP_COMPLAIN)))
6100 return error_mark_node;
6103 perform_or_defer_access_check (cand->access_path, access_fn, fn);
6106 /* If we're checking for implicit delete, don't bother with argument
6108 if (flags & LOOKUP_SPECULATIVE)
6110 if (DECL_DELETED_FN (fn))
6112 if (flags & LOOKUP_COMPLAIN)
6114 return error_mark_node;
6116 if (cand->viable == 1)
6118 else if (!(flags & LOOKUP_COMPLAIN))
6119 /* Reject bad conversions now. */
6120 return error_mark_node;
6121 /* else continue to get conversion error. */
6124 /* Find maximum size of vector to hold converted arguments. */
6125 parmlen = list_length (parm);
6126 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0);
6127 if (parmlen > nargs)
6129 argarray = XALLOCAVEC (tree, nargs);
6131 /* The implicit parameters to a constructor are not considered by overload
6132 resolution, and must be of the proper type. */
6133 if (DECL_CONSTRUCTOR_P (fn))
6135 if (first_arg != NULL_TREE)
6137 argarray[j++] = first_arg;
6138 first_arg = NULL_TREE;
6142 argarray[j++] = VEC_index (tree, args, arg_index);
6145 parm = TREE_CHAIN (parm);
6146 /* We should never try to call the abstract constructor. */
6147 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
6149 if (DECL_HAS_VTT_PARM_P (fn))
6151 argarray[j++] = VEC_index (tree, args, arg_index);
6153 parm = TREE_CHAIN (parm);
6156 /* Bypass access control for 'this' parameter. */
6157 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6159 tree parmtype = TREE_VALUE (parm);
6160 tree arg = (first_arg != NULL_TREE
6162 : VEC_index (tree, args, arg_index));
6163 tree argtype = TREE_TYPE (arg);
6167 if (convs[i]->bad_p)
6169 if (complain & tf_error)
6170 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
6171 TREE_TYPE (argtype), fn);
6173 return error_mark_node;
6176 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
6177 X is called for an object that is not of type X, or of a type
6178 derived from X, the behavior is undefined.
6180 So we can assume that anything passed as 'this' is non-null, and
6181 optimize accordingly. */
6182 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
6183 /* Convert to the base in which the function was declared. */
6184 gcc_assert (cand->conversion_path != NULL_TREE);
6185 converted_arg = build_base_path (PLUS_EXPR,
6187 cand->conversion_path,
6189 /* Check that the base class is accessible. */
6190 if (!accessible_base_p (TREE_TYPE (argtype),
6191 BINFO_TYPE (cand->conversion_path), true))
6192 error ("%qT is not an accessible base of %qT",
6193 BINFO_TYPE (cand->conversion_path),
6194 TREE_TYPE (argtype));
6195 /* If fn was found by a using declaration, the conversion path
6196 will be to the derived class, not the base declaring fn. We
6197 must convert from derived to base. */
6198 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
6199 TREE_TYPE (parmtype), ba_unique, NULL);
6200 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
6203 argarray[j++] = converted_arg;
6204 parm = TREE_CHAIN (parm);
6205 if (first_arg != NULL_TREE)
6206 first_arg = NULL_TREE;
6213 gcc_assert (first_arg == NULL_TREE);
6214 for (; arg_index < VEC_length (tree, args) && parm;
6215 parm = TREE_CHAIN (parm), ++arg_index, ++i)
6217 tree type = TREE_VALUE (parm);
6218 tree arg = VEC_index (tree, args, arg_index);
6222 /* Warn about initializer_list deduction that isn't currently in the
6224 if (cxx_dialect > cxx98
6225 && flag_deduce_init_list
6226 && cand->template_decl
6227 && is_std_init_list (non_reference (type))
6228 && BRACE_ENCLOSED_INITIALIZER_P (arg))
6230 tree tmpl = TI_TEMPLATE (cand->template_decl);
6231 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
6232 tree patparm = get_pattern_parm (realparm, tmpl);
6233 tree pattype = TREE_TYPE (patparm);
6234 if (PACK_EXPANSION_P (pattype))
6235 pattype = PACK_EXPANSION_PATTERN (pattype);
6236 pattype = non_reference (pattype);
6238 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
6239 && (cand->explicit_targs == NULL_TREE
6240 || (TREE_VEC_LENGTH (cand->explicit_targs)
6241 <= TEMPLATE_TYPE_IDX (pattype))))
6243 pedwarn (input_location, 0, "deducing %qT as %qT",
6244 non_reference (TREE_TYPE (patparm)),
6245 non_reference (type));
6246 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
6247 pedwarn (input_location, 0,
6248 " (you can disable this with -fno-deduce-init-list)");
6252 val = convert_like_with_context (conv, arg, fn, i-is_method, complain);
6254 val = convert_for_arg_passing (type, val);
6255 if (val == error_mark_node)
6256 return error_mark_node;
6258 argarray[j++] = val;
6261 /* Default arguments */
6262 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
6263 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
6264 TREE_PURPOSE (parm),
6267 for (; arg_index < VEC_length (tree, args); ++arg_index)
6269 tree a = VEC_index (tree, args, arg_index);
6270 if (magic_varargs_p (fn))
6271 /* Do no conversions for magic varargs. */
6272 a = mark_type_use (a);
6274 a = convert_arg_to_ellipsis (a);
6278 gcc_assert (j <= nargs);
6281 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
6282 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
6284 /* Avoid actually calling copy constructors and copy assignment operators,
6287 if (! flag_elide_constructors)
6288 /* Do things the hard way. */;
6289 else if (cand->num_convs == 1
6290 && (DECL_COPY_CONSTRUCTOR_P (fn)
6291 || DECL_MOVE_CONSTRUCTOR_P (fn)))
6294 tree arg = argarray[num_artificial_parms_for (fn)];
6296 bool trivial = trivial_fn_p (fn);
6298 /* Pull out the real argument, disregarding const-correctness. */
6300 while (CONVERT_EXPR_P (targ)
6301 || TREE_CODE (targ) == NON_LVALUE_EXPR)
6302 targ = TREE_OPERAND (targ, 0);
6303 if (TREE_CODE (targ) == ADDR_EXPR)
6305 targ = TREE_OPERAND (targ, 0);
6306 if (!same_type_ignoring_top_level_qualifiers_p
6307 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
6316 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6318 /* [class.copy]: the copy constructor is implicitly defined even if
6319 the implementation elided its use. */
6320 if (!trivial || DECL_DELETED_FN (fn))
6323 already_used = true;
6326 /* If we're creating a temp and we already have one, don't create a
6327 new one. If we're not creating a temp but we get one, use
6328 INIT_EXPR to collapse the temp into our target. Otherwise, if the
6329 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
6330 temp or an INIT_EXPR otherwise. */
6332 if (integer_zerop (fa))
6334 if (TREE_CODE (arg) == TARGET_EXPR)
6337 return force_target_expr (DECL_CONTEXT (fn), arg);
6339 else if (TREE_CODE (arg) == TARGET_EXPR || trivial)
6341 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL,
6344 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
6348 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
6349 && trivial_fn_p (fn)
6350 && !DECL_DELETED_FN (fn))
6352 tree to = stabilize_reference
6353 (cp_build_indirect_ref (argarray[0], RO_NULL, complain));
6354 tree type = TREE_TYPE (to);
6355 tree as_base = CLASSTYPE_AS_BASE (type);
6356 tree arg = argarray[1];
6358 if (is_really_empty_class (type))
6360 /* Avoid copying empty classes. */
6361 val = build2 (COMPOUND_EXPR, void_type_node, to, arg);
6362 TREE_NO_WARNING (val) = 1;
6363 val = build2 (COMPOUND_EXPR, type, val, to);
6364 TREE_NO_WARNING (val) = 1;
6366 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
6368 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6369 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
6373 /* We must only copy the non-tail padding parts.
6374 Use __builtin_memcpy for the bitwise copy.
6375 FIXME fix 22488 so we can go back to using MODIFY_EXPR
6376 instead of an explicit call to memcpy. */
6378 tree arg0, arg1, arg2, t;
6379 tree test = NULL_TREE;
6381 arg2 = TYPE_SIZE_UNIT (as_base);
6383 arg0 = cp_build_addr_expr (to, complain);
6385 if (!can_trust_pointer_alignment ())
6387 /* If we can't be sure about pointer alignment, a call
6388 to __builtin_memcpy is expanded as a call to memcpy, which
6389 is invalid with identical args. Otherwise it is
6390 expanded as a block move, which should be safe. */
6391 arg0 = save_expr (arg0);
6392 arg1 = save_expr (arg1);
6393 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
6395 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
6396 t = build_call_n (t, 3, arg0, arg1, arg2);
6398 t = convert (TREE_TYPE (arg0), t);
6400 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
6401 val = cp_build_indirect_ref (t, RO_NULL, complain);
6402 TREE_NO_WARNING (val) = 1;
6407 /* FIXME handle trivial default constructor and destructor, too. */
6412 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
6415 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
6418 gcc_assert (binfo && binfo != error_mark_node);
6420 /* Warn about deprecated virtual functions now, since we're about
6421 to throw away the decl. */
6422 if (TREE_DEPRECATED (fn))
6423 warn_deprecated_use (fn, NULL_TREE);
6425 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
6426 if (TREE_SIDE_EFFECTS (argarray[0]))
6427 argarray[0] = save_expr (argarray[0]);
6428 t = build_pointer_type (TREE_TYPE (fn));
6429 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
6430 fn = build_java_interface_fn_ref (fn, argarray[0]);
6432 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
6436 fn = build_addr_func (fn);
6438 return build_cxx_call (fn, nargs, argarray);
6441 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
6442 This function performs no overload resolution, conversion, or other
6443 high-level operations. */
6446 build_cxx_call (tree fn, int nargs, tree *argarray)
6450 fn = build_call_a (fn, nargs, argarray);
6452 /* If this call might throw an exception, note that fact. */
6453 fndecl = get_callee_fndecl (fn);
6454 if ((!fndecl || !TREE_NOTHROW (fndecl))
6455 && at_function_scope_p ()
6457 && cp_function_chain)
6458 cp_function_chain->can_throw = 1;
6460 /* Check that arguments to builtin functions match the expectations. */
6462 && DECL_BUILT_IN (fndecl)
6463 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6464 && !check_builtin_function_arguments (fndecl, nargs, argarray))
6465 return error_mark_node;
6467 /* Some built-in function calls will be evaluated at compile-time in
6469 fn = fold_if_not_in_template (fn);
6471 if (VOID_TYPE_P (TREE_TYPE (fn)))
6474 fn = require_complete_type (fn);
6475 if (fn == error_mark_node)
6476 return error_mark_node;
6478 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
6479 fn = build_cplus_new (TREE_TYPE (fn), fn);
6480 return convert_from_reference (fn);
6483 static GTY(()) tree java_iface_lookup_fn;
6485 /* Make an expression which yields the address of the Java interface
6486 method FN. This is achieved by generating a call to libjava's
6487 _Jv_LookupInterfaceMethodIdx(). */
6490 build_java_interface_fn_ref (tree fn, tree instance)
6492 tree lookup_fn, method, idx;
6493 tree klass_ref, iface, iface_ref;
6496 if (!java_iface_lookup_fn)
6498 tree ftype = build_function_type_list (ptr_type_node,
6499 ptr_type_node, ptr_type_node,
6500 java_int_type_node, NULL_TREE);
6501 java_iface_lookup_fn
6502 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype,
6503 0, NOT_BUILT_IN, NULL, NULL_TREE);
6506 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
6507 This is the first entry in the vtable. */
6508 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL,
6509 tf_warning_or_error),
6512 /* Get the java.lang.Class pointer for the interface being called. */
6513 iface = DECL_CONTEXT (fn);
6514 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
6515 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
6516 || DECL_CONTEXT (iface_ref) != iface)
6518 error ("could not find class$ field in java interface type %qT",
6520 return error_mark_node;
6522 iface_ref = build_address (iface_ref);
6523 iface_ref = convert (build_pointer_type (iface), iface_ref);
6525 /* Determine the itable index of FN. */
6527 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method))
6529 if (!DECL_VIRTUAL_P (method))
6535 idx = build_int_cst (NULL_TREE, i);
6537 lookup_fn = build1 (ADDR_EXPR,
6538 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
6539 java_iface_lookup_fn);
6540 return build_call_nary (ptr_type_node, lookup_fn,
6541 3, klass_ref, iface_ref, idx);
6544 /* Returns the value to use for the in-charge parameter when making a
6545 call to a function with the indicated NAME.
6547 FIXME:Can't we find a neater way to do this mapping? */
6550 in_charge_arg_for_name (tree name)
6552 if (name == base_ctor_identifier
6553 || name == base_dtor_identifier)
6554 return integer_zero_node;
6555 else if (name == complete_ctor_identifier)
6556 return integer_one_node;
6557 else if (name == complete_dtor_identifier)
6558 return integer_two_node;
6559 else if (name == deleting_dtor_identifier)
6560 return integer_three_node;
6562 /* This function should only be called with one of the names listed
6568 /* Build a call to a constructor, destructor, or an assignment
6569 operator for INSTANCE, an expression with class type. NAME
6570 indicates the special member function to call; *ARGS are the
6571 arguments. ARGS may be NULL. This may change ARGS. BINFO
6572 indicates the base of INSTANCE that is to be passed as the `this'
6573 parameter to the member function called.
6575 FLAGS are the LOOKUP_* flags to use when processing the call.
6577 If NAME indicates a complete object constructor, INSTANCE may be
6578 NULL_TREE. In this case, the caller will call build_cplus_new to
6579 store the newly constructed object into a VAR_DECL. */
6582 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args,
6583 tree binfo, int flags, tsubst_flags_t complain)
6586 /* The type of the subobject to be constructed or destroyed. */
6588 VEC(tree,gc) *allocated = NULL;
6591 gcc_assert (name == complete_ctor_identifier
6592 || name == base_ctor_identifier
6593 || name == complete_dtor_identifier
6594 || name == base_dtor_identifier
6595 || name == deleting_dtor_identifier
6596 || name == ansi_assopname (NOP_EXPR));
6599 /* Resolve the name. */
6600 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
6601 return error_mark_node;
6603 binfo = TYPE_BINFO (binfo);
6606 gcc_assert (binfo != NULL_TREE);
6608 class_type = BINFO_TYPE (binfo);
6610 /* Handle the special case where INSTANCE is NULL_TREE. */
6611 if (name == complete_ctor_identifier && !instance)
6613 instance = build_int_cst (build_pointer_type (class_type), 0);
6614 instance = build1 (INDIRECT_REF, class_type, instance);
6618 if (name == complete_dtor_identifier
6619 || name == base_dtor_identifier
6620 || name == deleting_dtor_identifier)
6621 gcc_assert (args == NULL || VEC_empty (tree, *args));
6623 /* Convert to the base class, if necessary. */
6624 if (!same_type_ignoring_top_level_qualifiers_p
6625 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
6627 if (name != ansi_assopname (NOP_EXPR))
6628 /* For constructors and destructors, either the base is
6629 non-virtual, or it is virtual but we are doing the
6630 conversion from a constructor or destructor for the
6631 complete object. In either case, we can convert
6633 instance = convert_to_base_statically (instance, binfo);
6635 /* However, for assignment operators, we must convert
6636 dynamically if the base is virtual. */
6637 instance = build_base_path (PLUS_EXPR, instance,
6638 binfo, /*nonnull=*/1);
6642 gcc_assert (instance != NULL_TREE);
6644 fns = lookup_fnfields (binfo, name, 1);
6646 /* When making a call to a constructor or destructor for a subobject
6647 that uses virtual base classes, pass down a pointer to a VTT for
6649 if ((name == base_ctor_identifier
6650 || name == base_dtor_identifier)
6651 && CLASSTYPE_VBASECLASSES (class_type))
6656 /* If the current function is a complete object constructor
6657 or destructor, then we fetch the VTT directly.
6658 Otherwise, we look it up using the VTT we were given. */
6659 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
6660 vtt = decay_conversion (vtt);
6661 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
6662 build2 (EQ_EXPR, boolean_type_node,
6663 current_in_charge_parm, integer_zero_node),
6666 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
6667 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
6668 BINFO_SUBVTT_INDEX (binfo));
6672 allocated = make_tree_vector ();
6676 VEC_safe_insert (tree, gc, *args, 0, sub_vtt);
6679 ret = build_new_method_call (instance, fns, args,
6680 TYPE_BINFO (BINFO_TYPE (binfo)),
6684 if (allocated != NULL)
6685 release_tree_vector (allocated);
6690 /* Return the NAME, as a C string. The NAME indicates a function that
6691 is a member of TYPE. *FREE_P is set to true if the caller must
6692 free the memory returned.
6694 Rather than go through all of this, we should simply set the names
6695 of constructors and destructors appropriately, and dispense with
6696 ctor_identifier, dtor_identifier, etc. */
6699 name_as_c_string (tree name, tree type, bool *free_p)
6703 /* Assume that we will not allocate memory. */
6705 /* Constructors and destructors are special. */
6706 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6709 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))));
6710 /* For a destructor, add the '~'. */
6711 if (name == complete_dtor_identifier
6712 || name == base_dtor_identifier
6713 || name == deleting_dtor_identifier)
6715 pretty_name = concat ("~", pretty_name, NULL);
6716 /* Remember that we need to free the memory allocated. */
6720 else if (IDENTIFIER_TYPENAME_P (name))
6722 pretty_name = concat ("operator ",
6723 type_as_string_translate (TREE_TYPE (name),
6724 TFF_PLAIN_IDENTIFIER),
6726 /* Remember that we need to free the memory allocated. */
6730 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name)));
6735 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6736 be set, upon return, to the function called. ARGS may be NULL.
6737 This may change ARGS. */
6740 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args,
6741 tree conversion_path, int flags,
6742 tree *fn_p, tsubst_flags_t complain)
6744 struct z_candidate *candidates = 0, *cand;
6745 tree explicit_targs = NULL_TREE;
6746 tree basetype = NULL_TREE;
6749 tree first_mem_arg = NULL_TREE;
6752 bool skip_first_for_error;
6753 VEC(tree,gc) *user_args;
6756 int template_only = 0;
6760 VEC(tree,gc) *orig_args = NULL;
6763 gcc_assert (instance != NULL_TREE);
6765 /* We don't know what function we're going to call, yet. */
6769 if (error_operand_p (instance)
6770 || !fns || error_operand_p (fns))
6771 return error_mark_node;
6773 if (!BASELINK_P (fns))
6775 if (complain & tf_error)
6776 error ("call to non-function %qD", fns);
6777 return error_mark_node;
6780 orig_instance = instance;
6783 /* Dismantle the baselink to collect all the information we need. */
6784 if (!conversion_path)
6785 conversion_path = BASELINK_BINFO (fns);
6786 access_binfo = BASELINK_ACCESS_BINFO (fns);
6787 optype = BASELINK_OPTYPE (fns);
6788 fns = BASELINK_FUNCTIONS (fns);
6789 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
6791 explicit_targs = TREE_OPERAND (fns, 1);
6792 fns = TREE_OPERAND (fns, 0);
6795 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
6796 || TREE_CODE (fns) == TEMPLATE_DECL
6797 || TREE_CODE (fns) == OVERLOAD);
6798 fn = get_first_fn (fns);
6799 name = DECL_NAME (fn);
6801 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
6802 gcc_assert (CLASS_TYPE_P (basetype));
6804 if (processing_template_decl)
6806 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
6807 instance = build_non_dependent_expr (instance);
6809 make_args_non_dependent (*args);
6812 user_args = args == NULL ? NULL : *args;
6813 /* Under DR 147 A::A() is an invalid constructor call,
6814 not a functional cast. */
6815 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
6817 if (! (complain & tf_error))
6818 return error_mark_node;
6820 permerror (input_location,
6821 "cannot call constructor %<%T::%D%> directly",
6823 permerror (input_location, " for a function-style cast, remove the "
6824 "redundant %<::%D%>", name);
6825 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
6830 /* Figure out whether to skip the first argument for the error
6831 message we will display to users if an error occurs. We don't
6832 want to display any compiler-generated arguments. The "this"
6833 pointer hasn't been added yet. However, we must remove the VTT
6834 pointer if this is a call to a base-class constructor or
6836 skip_first_for_error = false;
6837 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6839 /* Callers should explicitly indicate whether they want to construct
6840 the complete object or just the part without virtual bases. */
6841 gcc_assert (name != ctor_identifier);
6842 /* Similarly for destructors. */
6843 gcc_assert (name != dtor_identifier);
6844 /* Remove the VTT pointer, if present. */
6845 if ((name == base_ctor_identifier || name == base_dtor_identifier)
6846 && CLASSTYPE_VBASECLASSES (basetype))
6847 skip_first_for_error = true;
6850 /* Process the argument list. */
6851 if (args != NULL && *args != NULL)
6853 *args = resolve_args (*args);
6855 return error_mark_node;
6858 instance_ptr = build_this (instance);
6860 /* It's OK to call destructors and constructors on cv-qualified objects.
6861 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6863 if (DECL_DESTRUCTOR_P (fn)
6864 || DECL_CONSTRUCTOR_P (fn))
6866 tree type = build_pointer_type (basetype);
6867 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
6868 instance_ptr = build_nop (type, instance_ptr);
6870 if (DECL_DESTRUCTOR_P (fn))
6871 name = complete_dtor_identifier;
6873 first_mem_arg = instance_ptr;
6875 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6876 p = conversion_obstack_alloc (0);
6878 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6879 initializer, not T({ }). */
6880 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args)
6881 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0))
6882 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0)))
6884 gcc_assert (VEC_length (tree, *args) == 1
6885 && !(flags & LOOKUP_ONLYCONVERTING));
6887 add_list_candidates (fns, first_mem_arg, VEC_index (tree, *args, 0),
6888 basetype, explicit_targs, template_only,
6889 conversion_path, access_binfo, flags, &candidates);
6893 add_candidates (fns, first_mem_arg, user_args, optype,
6894 explicit_targs, template_only, conversion_path,
6895 access_binfo, flags, &candidates);
6897 any_viable_p = false;
6898 candidates = splice_viable (candidates, pedantic, &any_viable_p);
6902 if (complain & tf_error)
6904 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
6905 cxx_incomplete_type_error (instance_ptr, basetype);
6907 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
6908 basetype, optype, build_tree_list_vec (user_args),
6909 TREE_TYPE (TREE_TYPE (instance_ptr)));
6916 pretty_name = name_as_c_string (name, basetype, &free_p);
6917 arglist = build_tree_list_vec (user_args);
6918 if (skip_first_for_error)
6919 arglist = TREE_CHAIN (arglist);
6920 error ("no matching function for call to %<%T::%s(%A)%#V%>",
6921 basetype, pretty_name, arglist,
6922 TREE_TYPE (TREE_TYPE (instance_ptr)));
6926 print_z_candidates (location_of (name), candidates);
6928 call = error_mark_node;
6932 cand = tourney (candidates);
6939 if (complain & tf_error)
6941 pretty_name = name_as_c_string (name, basetype, &free_p);
6942 arglist = build_tree_list_vec (user_args);
6943 if (skip_first_for_error)
6944 arglist = TREE_CHAIN (arglist);
6945 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
6947 print_z_candidates (location_of (name), candidates);
6951 call = error_mark_node;
6957 if (!(flags & LOOKUP_NONVIRTUAL)
6958 && DECL_PURE_VIRTUAL_P (fn)
6959 && instance == current_class_ref
6960 && (DECL_CONSTRUCTOR_P (current_function_decl)
6961 || DECL_DESTRUCTOR_P (current_function_decl))
6962 && (complain & tf_warning))
6963 /* This is not an error, it is runtime undefined
6965 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
6966 "pure virtual %q#D called from constructor"
6967 : "pure virtual %q#D called from destructor"),
6970 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
6971 && is_dummy_object (instance_ptr))
6973 if (complain & tf_error)
6974 error ("cannot call member function %qD without object",
6976 call = error_mark_node;
6980 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
6981 && resolves_to_fixed_type_p (instance, 0))
6982 flags |= LOOKUP_NONVIRTUAL;
6983 /* Now we know what function is being called. */
6986 /* Build the actual CALL_EXPR. */
6987 call = build_over_call (cand, flags, complain);
6988 /* In an expression of the form `a->f()' where `f' turns
6989 out to be a static member function, `a' is
6990 none-the-less evaluated. */
6991 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
6992 && !is_dummy_object (instance_ptr)
6993 && TREE_SIDE_EFFECTS (instance_ptr))
6994 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
6995 instance_ptr, call);
6996 else if (call != error_mark_node
6997 && DECL_DESTRUCTOR_P (cand->fn)
6998 && !VOID_TYPE_P (TREE_TYPE (call)))
6999 /* An explicit call of the form "x->~X()" has type
7000 "void". However, on platforms where destructors
7001 return "this" (i.e., those where
7002 targetm.cxx.cdtor_returns_this is true), such calls
7003 will appear to have a return value of pointer type
7004 to the low-level call machinery. We do not want to
7005 change the low-level machinery, since we want to be
7006 able to optimize "delete f()" on such platforms as
7007 "operator delete(~X(f()))" (rather than generating
7008 "t = f(), ~X(t), operator delete (t)"). */
7009 call = build_nop (void_type_node, call);
7014 if (processing_template_decl && call != error_mark_node)
7016 bool cast_to_void = false;
7018 if (TREE_CODE (call) == COMPOUND_EXPR)
7019 call = TREE_OPERAND (call, 1);
7020 else if (TREE_CODE (call) == NOP_EXPR)
7022 cast_to_void = true;
7023 call = TREE_OPERAND (call, 0);
7025 if (TREE_CODE (call) == INDIRECT_REF)
7026 call = TREE_OPERAND (call, 0);
7027 call = (build_min_non_dep_call_vec
7029 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
7030 orig_instance, orig_fns, NULL_TREE),
7032 call = convert_from_reference (call);
7034 call = build_nop (void_type_node, call);
7037 /* Free all the conversions we allocated. */
7038 obstack_free (&conversion_obstack, p);
7040 if (orig_args != NULL)
7041 release_tree_vector (orig_args);
7046 /* Returns true iff standard conversion sequence ICS1 is a proper
7047 subsequence of ICS2. */
7050 is_subseq (conversion *ics1, conversion *ics2)
7052 /* We can assume that a conversion of the same code
7053 between the same types indicates a subsequence since we only get
7054 here if the types we are converting from are the same. */
7056 while (ics1->kind == ck_rvalue
7057 || ics1->kind == ck_lvalue)
7058 ics1 = ics1->u.next;
7062 while (ics2->kind == ck_rvalue
7063 || ics2->kind == ck_lvalue)
7064 ics2 = ics2->u.next;
7066 if (ics2->kind == ck_user
7067 || ics2->kind == ck_ambig
7068 || ics2->kind == ck_aggr
7069 || ics2->kind == ck_list
7070 || ics2->kind == ck_identity)
7071 /* At this point, ICS1 cannot be a proper subsequence of
7072 ICS2. We can get a USER_CONV when we are comparing the
7073 second standard conversion sequence of two user conversion
7077 ics2 = ics2->u.next;
7079 if (ics2->kind == ics1->kind
7080 && same_type_p (ics2->type, ics1->type)
7081 && same_type_p (ics2->u.next->type,
7082 ics1->u.next->type))
7087 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
7088 be any _TYPE nodes. */
7091 is_properly_derived_from (tree derived, tree base)
7093 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
7096 /* We only allow proper derivation here. The DERIVED_FROM_P macro
7097 considers every class derived from itself. */
7098 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
7099 && DERIVED_FROM_P (base, derived));
7102 /* We build the ICS for an implicit object parameter as a pointer
7103 conversion sequence. However, such a sequence should be compared
7104 as if it were a reference conversion sequence. If ICS is the
7105 implicit conversion sequence for an implicit object parameter,
7106 modify it accordingly. */
7109 maybe_handle_implicit_object (conversion **ics)
7113 /* [over.match.funcs]
7115 For non-static member functions, the type of the
7116 implicit object parameter is "reference to cv X"
7117 where X is the class of which the function is a
7118 member and cv is the cv-qualification on the member
7119 function declaration. */
7120 conversion *t = *ics;
7121 tree reference_type;
7123 /* The `this' parameter is a pointer to a class type. Make the
7124 implicit conversion talk about a reference to that same class
7126 reference_type = TREE_TYPE (t->type);
7127 reference_type = build_reference_type (reference_type);
7129 if (t->kind == ck_qual)
7131 if (t->kind == ck_ptr)
7133 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
7134 t = direct_reference_binding (reference_type, t);
7136 t->rvaluedness_matches_p = 0;
7141 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
7142 and return the initial reference binding conversion. Otherwise,
7143 leave *ICS unchanged and return NULL. */
7146 maybe_handle_ref_bind (conversion **ics)
7148 if ((*ics)->kind == ck_ref_bind)
7150 conversion *old_ics = *ics;
7151 *ics = old_ics->u.next;
7152 (*ics)->user_conv_p = old_ics->user_conv_p;
7159 /* Compare two implicit conversion sequences according to the rules set out in
7160 [over.ics.rank]. Return values:
7162 1: ics1 is better than ics2
7163 -1: ics2 is better than ics1
7164 0: ics1 and ics2 are indistinguishable */
7167 compare_ics (conversion *ics1, conversion *ics2)
7173 tree deref_from_type1 = NULL_TREE;
7174 tree deref_from_type2 = NULL_TREE;
7175 tree deref_to_type1 = NULL_TREE;
7176 tree deref_to_type2 = NULL_TREE;
7177 conversion_rank rank1, rank2;
7179 /* REF_BINDING is nonzero if the result of the conversion sequence
7180 is a reference type. In that case REF_CONV is the reference
7181 binding conversion. */
7182 conversion *ref_conv1;
7183 conversion *ref_conv2;
7185 /* Handle implicit object parameters. */
7186 maybe_handle_implicit_object (&ics1);
7187 maybe_handle_implicit_object (&ics2);
7189 /* Handle reference parameters. */
7190 ref_conv1 = maybe_handle_ref_bind (&ics1);
7191 ref_conv2 = maybe_handle_ref_bind (&ics2);
7193 /* List-initialization sequence L1 is a better conversion sequence than
7194 list-initialization sequence L2 if L1 converts to
7195 std::initializer_list<X> for some X and L2 does not. */
7196 if (ics1->kind == ck_list && ics2->kind != ck_list)
7198 if (ics2->kind == ck_list && ics1->kind != ck_list)
7203 When comparing the basic forms of implicit conversion sequences (as
7204 defined in _over.best.ics_)
7206 --a standard conversion sequence (_over.ics.scs_) is a better
7207 conversion sequence than a user-defined conversion sequence
7208 or an ellipsis conversion sequence, and
7210 --a user-defined conversion sequence (_over.ics.user_) is a
7211 better conversion sequence than an ellipsis conversion sequence
7212 (_over.ics.ellipsis_). */
7213 rank1 = CONVERSION_RANK (ics1);
7214 rank2 = CONVERSION_RANK (ics2);
7218 else if (rank1 < rank2)
7221 if (rank1 == cr_bad)
7223 /* Both ICS are bad. We try to make a decision based on what would
7224 have happened if they'd been good. This is not an extension,
7225 we'll still give an error when we build up the call; this just
7226 helps us give a more helpful error message. */
7227 rank1 = BAD_CONVERSION_RANK (ics1);
7228 rank2 = BAD_CONVERSION_RANK (ics2);
7232 else if (rank1 < rank2)
7235 /* We couldn't make up our minds; try to figure it out below. */
7238 if (ics1->ellipsis_p)
7239 /* Both conversions are ellipsis conversions. */
7242 /* User-defined conversion sequence U1 is a better conversion sequence
7243 than another user-defined conversion sequence U2 if they contain the
7244 same user-defined conversion operator or constructor and if the sec-
7245 ond standard conversion sequence of U1 is better than the second
7246 standard conversion sequence of U2. */
7248 /* Handle list-conversion with the same code even though it isn't always
7249 ranked as a user-defined conversion and it doesn't have a second
7250 standard conversion sequence; it will still have the desired effect.
7251 Specifically, we need to do the reference binding comparison at the
7252 end of this function. */
7254 if (ics1->user_conv_p || ics1->kind == ck_list)
7259 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
7260 if (t1->kind == ck_ambig || t1->kind == ck_aggr
7261 || t1->kind == ck_list)
7263 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
7264 if (t2->kind == ck_ambig || t2->kind == ck_aggr
7265 || t2->kind == ck_list)
7268 if (t1->kind != t2->kind)
7270 else if (t1->kind == ck_user)
7272 if (t1->cand->fn != t2->cand->fn)
7277 /* For ambiguous or aggregate conversions, use the target type as
7278 a proxy for the conversion function. */
7279 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
7283 /* We can just fall through here, after setting up
7284 FROM_TYPE1 and FROM_TYPE2. */
7285 from_type1 = t1->type;
7286 from_type2 = t2->type;
7293 /* We're dealing with two standard conversion sequences.
7297 Standard conversion sequence S1 is a better conversion
7298 sequence than standard conversion sequence S2 if
7300 --S1 is a proper subsequence of S2 (comparing the conversion
7301 sequences in the canonical form defined by _over.ics.scs_,
7302 excluding any Lvalue Transformation; the identity
7303 conversion sequence is considered to be a subsequence of
7304 any non-identity conversion sequence */
7307 while (t1->kind != ck_identity)
7309 from_type1 = t1->type;
7312 while (t2->kind != ck_identity)
7314 from_type2 = t2->type;
7317 /* One sequence can only be a subsequence of the other if they start with
7318 the same type. They can start with different types when comparing the
7319 second standard conversion sequence in two user-defined conversion
7321 if (same_type_p (from_type1, from_type2))
7323 if (is_subseq (ics1, ics2))
7325 if (is_subseq (ics2, ics1))
7333 --the rank of S1 is better than the rank of S2 (by the rules
7336 Standard conversion sequences are ordered by their ranks: an Exact
7337 Match is a better conversion than a Promotion, which is a better
7338 conversion than a Conversion.
7340 Two conversion sequences with the same rank are indistinguishable
7341 unless one of the following rules applies:
7343 --A conversion that does not a convert a pointer, pointer to member,
7344 or std::nullptr_t to bool is better than one that does.
7346 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
7347 so that we do not have to check it explicitly. */
7348 if (ics1->rank < ics2->rank)
7350 else if (ics2->rank < ics1->rank)
7353 to_type1 = ics1->type;
7354 to_type2 = ics2->type;
7356 /* A conversion from scalar arithmetic type to complex is worse than a
7357 conversion between scalar arithmetic types. */
7358 if (same_type_p (from_type1, from_type2)
7359 && ARITHMETIC_TYPE_P (from_type1)
7360 && ARITHMETIC_TYPE_P (to_type1)
7361 && ARITHMETIC_TYPE_P (to_type2)
7362 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
7363 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
7365 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
7371 if (TYPE_PTR_P (from_type1)
7372 && TYPE_PTR_P (from_type2)
7373 && TYPE_PTR_P (to_type1)
7374 && TYPE_PTR_P (to_type2))
7376 deref_from_type1 = TREE_TYPE (from_type1);
7377 deref_from_type2 = TREE_TYPE (from_type2);
7378 deref_to_type1 = TREE_TYPE (to_type1);
7379 deref_to_type2 = TREE_TYPE (to_type2);
7381 /* The rules for pointers to members A::* are just like the rules
7382 for pointers A*, except opposite: if B is derived from A then
7383 A::* converts to B::*, not vice versa. For that reason, we
7384 switch the from_ and to_ variables here. */
7385 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
7386 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
7387 || (TYPE_PTRMEMFUNC_P (from_type1)
7388 && TYPE_PTRMEMFUNC_P (from_type2)
7389 && TYPE_PTRMEMFUNC_P (to_type1)
7390 && TYPE_PTRMEMFUNC_P (to_type2)))
7392 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
7393 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
7394 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
7395 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
7398 if (deref_from_type1 != NULL_TREE
7399 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
7400 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
7402 /* This was one of the pointer or pointer-like conversions.
7406 --If class B is derived directly or indirectly from class A,
7407 conversion of B* to A* is better than conversion of B* to
7408 void*, and conversion of A* to void* is better than
7409 conversion of B* to void*. */
7410 if (TREE_CODE (deref_to_type1) == VOID_TYPE
7411 && TREE_CODE (deref_to_type2) == VOID_TYPE)
7413 if (is_properly_derived_from (deref_from_type1,
7416 else if (is_properly_derived_from (deref_from_type2,
7420 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
7421 || TREE_CODE (deref_to_type2) == VOID_TYPE)
7423 if (same_type_p (deref_from_type1, deref_from_type2))
7425 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
7427 if (is_properly_derived_from (deref_from_type1,
7431 /* We know that DEREF_TO_TYPE1 is `void' here. */
7432 else if (is_properly_derived_from (deref_from_type1,
7437 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
7438 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
7442 --If class B is derived directly or indirectly from class A
7443 and class C is derived directly or indirectly from B,
7445 --conversion of C* to B* is better than conversion of C* to
7448 --conversion of B* to A* is better than conversion of C* to
7450 if (same_type_p (deref_from_type1, deref_from_type2))
7452 if (is_properly_derived_from (deref_to_type1,
7455 else if (is_properly_derived_from (deref_to_type2,
7459 else if (same_type_p (deref_to_type1, deref_to_type2))
7461 if (is_properly_derived_from (deref_from_type2,
7464 else if (is_properly_derived_from (deref_from_type1,
7470 else if (CLASS_TYPE_P (non_reference (from_type1))
7471 && same_type_p (from_type1, from_type2))
7473 tree from = non_reference (from_type1);
7477 --binding of an expression of type C to a reference of type
7478 B& is better than binding an expression of type C to a
7479 reference of type A&
7481 --conversion of C to B is better than conversion of C to A, */
7482 if (is_properly_derived_from (from, to_type1)
7483 && is_properly_derived_from (from, to_type2))
7485 if (is_properly_derived_from (to_type1, to_type2))
7487 else if (is_properly_derived_from (to_type2, to_type1))
7491 else if (CLASS_TYPE_P (non_reference (to_type1))
7492 && same_type_p (to_type1, to_type2))
7494 tree to = non_reference (to_type1);
7498 --binding of an expression of type B to a reference of type
7499 A& is better than binding an expression of type C to a
7500 reference of type A&,
7502 --conversion of B to A is better than conversion of C to A */
7503 if (is_properly_derived_from (from_type1, to)
7504 && is_properly_derived_from (from_type2, to))
7506 if (is_properly_derived_from (from_type2, from_type1))
7508 else if (is_properly_derived_from (from_type1, from_type2))
7515 --S1 and S2 differ only in their qualification conversion and yield
7516 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
7517 qualification signature of type T1 is a proper subset of the cv-
7518 qualification signature of type T2 */
7519 if (ics1->kind == ck_qual
7520 && ics2->kind == ck_qual
7521 && same_type_p (from_type1, from_type2))
7523 int result = comp_cv_qual_signature (to_type1, to_type2);
7530 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
7531 to an implicit object parameter, and either S1 binds an lvalue reference
7532 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
7533 reference to an rvalue and S2 binds an lvalue reference
7534 (C++0x draft standard, 13.3.3.2)
7536 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
7537 types to which the references refer are the same type except for
7538 top-level cv-qualifiers, and the type to which the reference
7539 initialized by S2 refers is more cv-qualified than the type to
7540 which the reference initialized by S1 refers */
7542 if (ref_conv1 && ref_conv2)
7544 if (!ref_conv1->this_p && !ref_conv2->this_p
7545 && (TYPE_REF_IS_RVALUE (ref_conv1->type)
7546 != TYPE_REF_IS_RVALUE (ref_conv2->type)))
7548 if (ref_conv1->rvaluedness_matches_p)
7550 if (ref_conv2->rvaluedness_matches_p)
7554 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
7555 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
7556 TREE_TYPE (ref_conv1->type));
7559 /* Neither conversion sequence is better than the other. */
7563 /* The source type for this standard conversion sequence. */
7566 source_type (conversion *t)
7568 for (;; t = t->u.next)
7570 if (t->kind == ck_user
7571 || t->kind == ck_ambig
7572 || t->kind == ck_identity)
7578 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7579 a pointer to LOSER and re-running joust to produce the warning if WINNER
7580 is actually used. */
7583 add_warning (struct z_candidate *winner, struct z_candidate *loser)
7585 candidate_warning *cw = (candidate_warning *)
7586 conversion_obstack_alloc (sizeof (candidate_warning));
7588 cw->next = winner->warnings;
7589 winner->warnings = cw;
7592 /* Compare two candidates for overloading as described in
7593 [over.match.best]. Return values:
7595 1: cand1 is better than cand2
7596 -1: cand2 is better than cand1
7597 0: cand1 and cand2 are indistinguishable */
7600 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
7603 int off1 = 0, off2 = 0;
7607 /* Candidates that involve bad conversions are always worse than those
7609 if (cand1->viable > cand2->viable)
7611 if (cand1->viable < cand2->viable)
7614 /* If we have two pseudo-candidates for conversions to the same type,
7615 or two candidates for the same function, arbitrarily pick one. */
7616 if (cand1->fn == cand2->fn
7617 && (IS_TYPE_OR_DECL_P (cand1->fn)))
7620 /* a viable function F1
7621 is defined to be a better function than another viable function F2 if
7622 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7623 ICSi(F2), and then */
7625 /* for some argument j, ICSj(F1) is a better conversion sequence than
7628 /* For comparing static and non-static member functions, we ignore
7629 the implicit object parameter of the non-static function. The
7630 standard says to pretend that the static function has an object
7631 parm, but that won't work with operator overloading. */
7632 len = cand1->num_convs;
7633 if (len != cand2->num_convs)
7635 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
7636 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
7638 gcc_assert (static_1 != static_2);
7649 for (i = 0; i < len; ++i)
7651 conversion *t1 = cand1->convs[i + off1];
7652 conversion *t2 = cand2->convs[i + off2];
7653 int comp = compare_ics (t1, t2);
7658 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
7659 == cr_std + cr_promotion)
7660 && t1->kind == ck_std
7661 && t2->kind == ck_std
7662 && TREE_CODE (t1->type) == INTEGER_TYPE
7663 && TREE_CODE (t2->type) == INTEGER_TYPE
7664 && (TYPE_PRECISION (t1->type)
7665 == TYPE_PRECISION (t2->type))
7666 && (TYPE_UNSIGNED (t1->u.next->type)
7667 || (TREE_CODE (t1->u.next->type)
7670 tree type = t1->u.next->type;
7672 struct z_candidate *w, *l;
7674 type1 = t1->type, type2 = t2->type,
7675 w = cand1, l = cand2;
7677 type1 = t2->type, type2 = t1->type,
7678 w = cand2, l = cand1;
7682 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
7683 type, type1, type2);
7684 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
7690 if (winner && comp != winner)
7699 /* warn about confusing overload resolution for user-defined conversions,
7700 either between a constructor and a conversion op, or between two
7702 if (winner && warn_conversion && cand1->second_conv
7703 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
7704 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
7706 struct z_candidate *w, *l;
7707 bool give_warning = false;
7710 w = cand1, l = cand2;
7712 w = cand2, l = cand1;
7714 /* We don't want to complain about `X::operator T1 ()'
7715 beating `X::operator T2 () const', when T2 is a no less
7716 cv-qualified version of T1. */
7717 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
7718 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
7720 tree t = TREE_TYPE (TREE_TYPE (l->fn));
7721 tree f = TREE_TYPE (TREE_TYPE (w->fn));
7723 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
7728 if (!comp_ptr_ttypes (t, f))
7729 give_warning = true;
7732 give_warning = true;
7738 tree source = source_type (w->convs[0]);
7739 if (! DECL_CONSTRUCTOR_P (w->fn))
7740 source = TREE_TYPE (source);
7741 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
7742 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
7743 source, w->second_conv->type))
7745 inform (input_location, " because conversion sequence for the argument is better");
7756 F1 is a non-template function and F2 is a template function
7759 if (!cand1->template_decl && cand2->template_decl)
7761 else if (cand1->template_decl && !cand2->template_decl)
7765 F1 and F2 are template functions and the function template for F1 is
7766 more specialized than the template for F2 according to the partial
7769 if (cand1->template_decl && cand2->template_decl)
7771 winner = more_specialized_fn
7772 (TI_TEMPLATE (cand1->template_decl),
7773 TI_TEMPLATE (cand2->template_decl),
7774 /* [temp.func.order]: The presence of unused ellipsis and default
7775 arguments has no effect on the partial ordering of function
7776 templates. add_function_candidate() will not have
7777 counted the "this" argument for constructors. */
7778 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
7784 the context is an initialization by user-defined conversion (see
7785 _dcl.init_ and _over.match.user_) and the standard conversion
7786 sequence from the return type of F1 to the destination type (i.e.,
7787 the type of the entity being initialized) is a better conversion
7788 sequence than the standard conversion sequence from the return type
7789 of F2 to the destination type. */
7791 if (cand1->second_conv)
7793 winner = compare_ics (cand1->second_conv, cand2->second_conv);
7798 /* Check whether we can discard a builtin candidate, either because we
7799 have two identical ones or matching builtin and non-builtin candidates.
7801 (Pedantically in the latter case the builtin which matched the user
7802 function should not be added to the overload set, but we spot it here.
7805 ... the builtin candidates include ...
7806 - do not have the same parameter type list as any non-template
7807 non-member candidate. */
7809 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
7810 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
7812 for (i = 0; i < len; ++i)
7813 if (!same_type_p (cand1->convs[i]->type,
7814 cand2->convs[i]->type))
7816 if (i == cand1->num_convs)
7818 if (cand1->fn == cand2->fn)
7819 /* Two built-in candidates; arbitrarily pick one. */
7821 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
7822 /* cand1 is built-in; prefer cand2. */
7825 /* cand2 is built-in; prefer cand1. */
7830 /* If the two function declarations represent the same function (this can
7831 happen with declarations in multiple scopes and arg-dependent lookup),
7832 arbitrarily choose one. But first make sure the default args we're
7834 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
7835 && equal_functions (cand1->fn, cand2->fn))
7837 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
7838 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
7840 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
7842 for (i = 0; i < len; ++i)
7844 /* Don't crash if the fn is variadic. */
7847 parms1 = TREE_CHAIN (parms1);
7848 parms2 = TREE_CHAIN (parms2);
7852 parms1 = TREE_CHAIN (parms1);
7854 parms2 = TREE_CHAIN (parms2);
7858 if (!cp_tree_equal (TREE_PURPOSE (parms1),
7859 TREE_PURPOSE (parms2)))
7863 permerror (input_location, "default argument mismatch in "
7864 "overload resolution");
7865 inform (input_location,
7866 " candidate 1: %q+#F", cand1->fn);
7867 inform (input_location,
7868 " candidate 2: %q+#F", cand2->fn);
7871 add_warning (cand1, cand2);
7874 parms1 = TREE_CHAIN (parms1);
7875 parms2 = TREE_CHAIN (parms2);
7883 /* Extension: If the worst conversion for one candidate is worse than the
7884 worst conversion for the other, take the first. */
7887 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
7888 struct z_candidate *w = 0, *l = 0;
7890 for (i = 0; i < len; ++i)
7892 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
7893 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
7894 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
7895 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
7898 winner = 1, w = cand1, l = cand2;
7900 winner = -1, w = cand2, l = cand1;
7903 /* Don't choose a deleted function over ambiguity. */
7904 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
7908 pedwarn (input_location, 0,
7909 "ISO C++ says that these are ambiguous, even "
7910 "though the worst conversion for the first is better than "
7911 "the worst conversion for the second:");
7912 print_z_candidate (_("candidate 1:"), w);
7913 print_z_candidate (_("candidate 2:"), l);
7921 gcc_assert (!winner);
7925 /* Given a list of candidates for overloading, find the best one, if any.
7926 This algorithm has a worst case of O(2n) (winner is last), and a best
7927 case of O(n/2) (totally ambiguous); much better than a sorting
7930 static struct z_candidate *
7931 tourney (struct z_candidate *candidates)
7933 struct z_candidate *champ = candidates, *challenger;
7935 int champ_compared_to_predecessor = 0;
7937 /* Walk through the list once, comparing each current champ to the next
7938 candidate, knocking out a candidate or two with each comparison. */
7940 for (challenger = champ->next; challenger; )
7942 fate = joust (champ, challenger, 0);
7944 challenger = challenger->next;
7949 champ = challenger->next;
7952 champ_compared_to_predecessor = 0;
7957 champ_compared_to_predecessor = 1;
7960 challenger = champ->next;
7964 /* Make sure the champ is better than all the candidates it hasn't yet
7965 been compared to. */
7967 for (challenger = candidates;
7969 && !(champ_compared_to_predecessor && challenger->next == champ);
7970 challenger = challenger->next)
7972 fate = joust (champ, challenger, 0);
7980 /* Returns nonzero if things of type FROM can be converted to TO. */
7983 can_convert (tree to, tree from)
7985 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT);
7988 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7991 can_convert_arg (tree to, tree from, tree arg, int flags)
7997 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7998 p = conversion_obstack_alloc (0);
8000 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8002 ok_p = (t && !t->bad_p);
8004 /* Free all the conversions we allocated. */
8005 obstack_free (&conversion_obstack, p);
8010 /* Like can_convert_arg, but allows dubious conversions as well. */
8013 can_convert_arg_bad (tree to, tree from, tree arg, int flags)
8018 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8019 p = conversion_obstack_alloc (0);
8020 /* Try to perform the conversion. */
8021 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8023 /* Free all the conversions we allocated. */
8024 obstack_free (&conversion_obstack, p);
8029 /* Convert EXPR to TYPE. Return the converted expression.
8031 Note that we allow bad conversions here because by the time we get to
8032 this point we are committed to doing the conversion. If we end up
8033 doing a bad conversion, convert_like will complain. */
8036 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags)
8041 if (error_operand_p (expr))
8042 return error_mark_node;
8044 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8045 p = conversion_obstack_alloc (0);
8047 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8053 if (complain & tf_error)
8055 /* If expr has unknown type, then it is an overloaded function.
8056 Call instantiate_type to get good error messages. */
8057 if (TREE_TYPE (expr) == unknown_type_node)
8058 instantiate_type (type, expr, complain);
8059 else if (invalid_nonstatic_memfn_p (expr, complain))
8060 /* We gave an error. */;
8062 error ("could not convert %qE to %qT", expr, type);
8064 expr = error_mark_node;
8066 else if (processing_template_decl)
8068 /* In a template, we are only concerned about determining the
8069 type of non-dependent expressions, so we do not have to
8070 perform the actual conversion. */
8071 if (TREE_TYPE (expr) != type)
8072 expr = build_nop (type, expr);
8075 expr = convert_like (conv, expr, complain);
8077 /* Free all the conversions we allocated. */
8078 obstack_free (&conversion_obstack, p);
8084 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
8086 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT);
8089 /* Convert EXPR to TYPE (as a direct-initialization) if that is
8090 permitted. If the conversion is valid, the converted expression is
8091 returned. Otherwise, NULL_TREE is returned, except in the case
8092 that TYPE is a class type; in that case, an error is issued. If
8093 C_CAST_P is true, then this direction initialization is taking
8094 place as part of a static_cast being attempted as part of a C-style
8098 perform_direct_initialization_if_possible (tree type,
8101 tsubst_flags_t complain)
8106 if (type == error_mark_node || error_operand_p (expr))
8107 return error_mark_node;
8110 If the destination type is a (possibly cv-qualified) class type:
8112 -- If the initialization is direct-initialization ...,
8113 constructors are considered. ... If no constructor applies, or
8114 the overload resolution is ambiguous, the initialization is
8116 if (CLASS_TYPE_P (type))
8118 VEC(tree,gc) *args = make_tree_vector_single (expr);
8119 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
8120 &args, type, LOOKUP_NORMAL, complain);
8121 release_tree_vector (args);
8122 return build_cplus_new (type, expr);
8125 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8126 p = conversion_obstack_alloc (0);
8128 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8131 if (!conv || conv->bad_p)
8134 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
8135 /*issue_conversion_warnings=*/false,
8139 /* Free all the conversions we allocated. */
8140 obstack_free (&conversion_obstack, p);
8145 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
8146 is being bound to a temporary. Create and return a new VAR_DECL
8147 with the indicated TYPE; this variable will store the value to
8148 which the reference is bound. */
8151 make_temporary_var_for_ref_to_temp (tree decl, tree type)
8155 /* Create the variable. */
8156 var = create_temporary_var (type);
8158 /* Register the variable. */
8159 if (TREE_STATIC (decl))
8161 /* Namespace-scope or local static; give it a mangled name. */
8164 TREE_STATIC (var) = 1;
8165 name = mangle_ref_init_variable (decl);
8166 DECL_NAME (var) = name;
8167 SET_DECL_ASSEMBLER_NAME (var, name);
8168 var = pushdecl_top_level (var);
8171 /* Create a new cleanup level if necessary. */
8172 maybe_push_cleanup_level (type);
8177 /* EXPR is the initializer for a variable DECL of reference or
8178 std::initializer_list type. Create, push and return a new VAR_DECL
8179 for the initializer so that it will live as long as DECL. Any
8180 cleanup for the new variable is returned through CLEANUP, and the
8181 code to initialize the new variable is returned through INITP. */
8184 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp)
8190 /* Create the temporary variable. */
8191 type = TREE_TYPE (expr);
8192 var = make_temporary_var_for_ref_to_temp (decl, type);
8193 layout_decl (var, 0);
8194 /* If the rvalue is the result of a function call it will be
8195 a TARGET_EXPR. If it is some other construct (such as a
8196 member access expression where the underlying object is
8197 itself the result of a function call), turn it into a
8198 TARGET_EXPR here. It is important that EXPR be a
8199 TARGET_EXPR below since otherwise the INIT_EXPR will
8200 attempt to make a bitwise copy of EXPR to initialize
8202 if (TREE_CODE (expr) != TARGET_EXPR)
8203 expr = get_target_expr (expr);
8205 /* If the initializer is constant, put it in DECL_INITIAL so we get
8206 static initialization and use in constant expressions. */
8207 init = maybe_constant_init (expr);
8208 if (TREE_CONSTANT (init))
8210 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
8212 /* 5.19 says that a constant expression can include an
8213 lvalue-rvalue conversion applied to "a glvalue of literal type
8214 that refers to a non-volatile temporary object initialized
8215 with a constant expression". Rather than try to communicate
8216 that this VAR_DECL is a temporary, just mark it constexpr.
8218 Currently this is only useful for initializer_list temporaries,
8219 since reference vars can't appear in constant expressions. */
8220 DECL_DECLARED_CONSTEXPR_P (var) = true;
8221 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
8222 TREE_CONSTANT (var) = true;
8224 DECL_INITIAL (var) = init;
8228 /* Create the INIT_EXPR that will initialize the temporary
8230 init = build2 (INIT_EXPR, type, var, expr);
8231 if (at_function_scope_p ())
8233 add_decl_expr (var);
8235 if (TREE_STATIC (var))
8236 init = add_stmt_to_compound (init, register_dtor_fn (var));
8238 *cleanup = cxx_maybe_build_cleanup (var);
8240 /* We must be careful to destroy the temporary only
8241 after its initialization has taken place. If the
8242 initialization throws an exception, then the
8243 destructor should not be run. We cannot simply
8244 transform INIT into something like:
8246 (INIT, ({ CLEANUP_STMT; }))
8248 because emit_local_var always treats the
8249 initializer as a full-expression. Thus, the
8250 destructor would run too early; it would run at the
8251 end of initializing the reference variable, rather
8252 than at the end of the block enclosing the
8255 The solution is to pass back a cleanup expression
8256 which the caller is responsible for attaching to
8257 the statement tree. */
8261 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
8262 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
8263 static_aggregates = tree_cons (NULL_TREE, var,
8271 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
8272 initializing a variable of that TYPE. If DECL is non-NULL, it is
8273 the VAR_DECL being initialized with the EXPR. (In that case, the
8274 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
8275 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
8276 return, if *CLEANUP is no longer NULL, it will be an expression
8277 that should be pushed as a cleanup after the returned expression
8278 is used to initialize DECL.
8280 Return the converted expression. */
8283 initialize_reference (tree type, tree expr, tree decl, tree *cleanup,
8284 tsubst_flags_t complain)
8289 if (type == error_mark_node || error_operand_p (expr))
8290 return error_mark_node;
8292 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8293 p = conversion_obstack_alloc (0);
8295 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
8297 if (!conv || conv->bad_p)
8299 if (complain & tf_error)
8301 if (!CP_TYPE_CONST_P (TREE_TYPE (type))
8302 && !TYPE_REF_IS_RVALUE (type)
8303 && !real_lvalue_p (expr))
8304 error ("invalid initialization of non-const reference of "
8305 "type %qT from an rvalue of type %qT",
8306 type, TREE_TYPE (expr));
8308 error ("invalid initialization of reference of type "
8309 "%qT from expression of type %qT", type,
8312 return error_mark_node;
8315 /* If DECL is non-NULL, then this special rule applies:
8319 The temporary to which the reference is bound or the temporary
8320 that is the complete object to which the reference is bound
8321 persists for the lifetime of the reference.
8323 The temporaries created during the evaluation of the expression
8324 initializing the reference, except the temporary to which the
8325 reference is bound, are destroyed at the end of the
8326 full-expression in which they are created.
8328 In that case, we store the converted expression into a new
8329 VAR_DECL in a new scope.
8331 However, we want to be careful not to create temporaries when
8332 they are not required. For example, given:
8335 struct D : public B {};
8339 there is no need to copy the return value from "f"; we can just
8340 extend its lifetime. Similarly, given:
8343 struct T { operator S(); };
8347 we can extend the lifetime of the return value of the conversion
8349 gcc_assert (conv->kind == ck_ref_bind);
8353 tree base_conv_type;
8355 /* Skip over the REF_BIND. */
8356 conv = conv->u.next;
8357 /* If the next conversion is a BASE_CONV, skip that too -- but
8358 remember that the conversion was required. */
8359 if (conv->kind == ck_base)
8361 base_conv_type = conv->type;
8362 conv = conv->u.next;
8365 base_conv_type = NULL_TREE;
8366 /* Perform the remainder of the conversion. */
8367 expr = convert_like_real (conv, expr,
8368 /*fn=*/NULL_TREE, /*argnum=*/0,
8370 /*issue_conversion_warnings=*/true,
8372 tf_warning_or_error);
8373 if (error_operand_p (expr))
8374 expr = error_mark_node;
8377 if (!lvalue_or_rvalue_with_address_p (expr))
8380 var = set_up_extended_ref_temp (decl, expr, cleanup, &init);
8381 /* Use its address to initialize the reference variable. */
8382 expr = build_address (var);
8384 expr = convert_to_base (expr,
8385 build_pointer_type (base_conv_type),
8386 /*check_access=*/true,
8387 /*nonnull=*/true, complain);
8389 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
8392 /* Take the address of EXPR. */
8393 expr = cp_build_addr_expr (expr, tf_warning_or_error);
8394 /* If a BASE_CONV was required, perform it now. */
8396 expr = (perform_implicit_conversion
8397 (build_pointer_type (base_conv_type), expr,
8398 tf_warning_or_error));
8399 expr = build_nop (type, expr);
8403 /* Perform the conversion. */
8404 expr = convert_like (conv, expr, tf_warning_or_error);
8406 /* Free all the conversions we allocated. */
8407 obstack_free (&conversion_obstack, p);
8412 /* Returns true iff TYPE is some variant of std::initializer_list. */
8415 is_std_init_list (tree type)
8417 /* Look through typedefs. */
8420 type = TYPE_MAIN_VARIANT (type);
8421 return (CLASS_TYPE_P (type)
8422 && CP_TYPE_CONTEXT (type) == std_node
8423 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
8426 /* Returns true iff DECL is a list constructor: i.e. a constructor which
8427 will accept an argument list of a single std::initializer_list<T>. */
8430 is_list_ctor (tree decl)
8432 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
8435 if (!args || args == void_list_node)
8438 arg = non_reference (TREE_VALUE (args));
8439 if (!is_std_init_list (arg))
8442 args = TREE_CHAIN (args);
8444 if (args && args != void_list_node && !TREE_PURPOSE (args))
8445 /* There are more non-defaulted parms. */
8451 #include "gt-cp-call.h"