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,
5 Free Software Foundation, Inc.
6 Contributed by Michael Tiemann (tiemann@cygnus.com) and
7 modified by Brendan Kehoe (brendan@cygnus.com).
9 This file is part of GCC.
11 GCC is free software; you can redistribute it and/or modify
12 it under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 3, or (at your option)
16 GCC is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License for more details.
21 You should have received a copy of the GNU General Public License
22 along with GCC; see the file COPYING3. If not see
23 <http://www.gnu.org/licenses/>. */
26 /* High-level class interface. */
30 #include "coretypes.h"
37 #include "diagnostic-core.h"
41 #include "langhooks.h"
42 #include "c-family/c-objc.h"
45 /* The various kinds of conversion. */
47 typedef enum conversion_kind {
63 /* The rank of the conversion. Order of the enumerals matters; better
64 conversions should come earlier in the list. */
66 typedef enum conversion_rank {
77 /* An implicit conversion sequence, in the sense of [over.best.ics].
78 The first conversion to be performed is at the end of the chain.
79 That conversion is always a cr_identity conversion. */
81 typedef struct conversion conversion;
83 /* The kind of conversion represented by this step. */
85 /* The rank of this conversion. */
87 BOOL_BITFIELD user_conv_p : 1;
88 BOOL_BITFIELD ellipsis_p : 1;
89 BOOL_BITFIELD this_p : 1;
90 /* True if this conversion would be permitted with a bending of
91 language standards, e.g. disregarding pointer qualifiers or
92 converting integers to pointers. */
93 BOOL_BITFIELD bad_p : 1;
94 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
95 temporary should be created to hold the result of the
97 BOOL_BITFIELD need_temporary_p : 1;
98 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
99 from a pointer-to-derived to pointer-to-base is being performed. */
100 BOOL_BITFIELD base_p : 1;
101 /* If KIND is ck_ref_bind, true when either an lvalue reference is
102 being bound to an lvalue expression or an rvalue reference is
103 being bound to an rvalue expression. If KIND is ck_rvalue,
104 true when we should treat an lvalue as an rvalue (12.8p33). If
105 KIND is ck_base, always false. */
106 BOOL_BITFIELD rvaluedness_matches_p: 1;
107 BOOL_BITFIELD check_narrowing: 1;
108 /* The type of the expression resulting from the conversion. */
111 /* The next conversion in the chain. Since the conversions are
112 arranged from outermost to innermost, the NEXT conversion will
113 actually be performed before this conversion. This variant is
114 used only when KIND is neither ck_identity nor ck_ambig. */
116 /* The expression at the beginning of the conversion chain. This
117 variant is used only if KIND is ck_identity or ck_ambig. */
119 /* The array of conversions for an initializer_list. */
122 /* The function candidate corresponding to this conversion
123 sequence. This field is only used if KIND is ck_user. */
124 struct z_candidate *cand;
127 #define CONVERSION_RANK(NODE) \
128 ((NODE)->bad_p ? cr_bad \
129 : (NODE)->ellipsis_p ? cr_ellipsis \
130 : (NODE)->user_conv_p ? cr_user \
133 #define BAD_CONVERSION_RANK(NODE) \
134 ((NODE)->ellipsis_p ? cr_ellipsis \
135 : (NODE)->user_conv_p ? cr_user \
138 static struct obstack conversion_obstack;
139 static bool conversion_obstack_initialized;
140 struct rejection_reason;
142 static struct z_candidate * tourney (struct z_candidate *);
143 static int equal_functions (tree, tree);
144 static int joust (struct z_candidate *, struct z_candidate *, bool);
145 static int compare_ics (conversion *, conversion *);
146 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
147 static tree build_java_interface_fn_ref (tree, tree);
148 #define convert_like(CONV, EXPR, COMPLAIN) \
149 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
150 /*issue_conversion_warnings=*/true, \
151 /*c_cast_p=*/false, (COMPLAIN))
152 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
153 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
154 /*issue_conversion_warnings=*/true, \
155 /*c_cast_p=*/false, (COMPLAIN))
156 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
157 bool, tsubst_flags_t);
158 static void op_error (enum tree_code, enum tree_code, tree, tree,
160 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
161 static void print_z_candidate (const char *, struct z_candidate *);
162 static void print_z_candidates (location_t, struct z_candidate *);
163 static tree build_this (tree);
164 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
165 static bool any_strictly_viable (struct z_candidate *);
166 static struct z_candidate *add_template_candidate
167 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
168 tree, tree, tree, int, unification_kind_t);
169 static struct z_candidate *add_template_candidate_real
170 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
171 tree, tree, tree, int, tree, unification_kind_t);
172 static struct z_candidate *add_template_conv_candidate
173 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
175 static void add_builtin_candidates
176 (struct z_candidate **, enum tree_code, enum tree_code,
178 static void add_builtin_candidate
179 (struct z_candidate **, enum tree_code, enum tree_code,
180 tree, tree, tree, tree *, tree *, int);
181 static bool is_complete (tree);
182 static void build_builtin_candidate
183 (struct z_candidate **, tree, tree, tree, tree *, tree *,
185 static struct z_candidate *add_conv_candidate
186 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
188 static struct z_candidate *add_function_candidate
189 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
191 static conversion *implicit_conversion (tree, tree, tree, bool, int);
192 static conversion *standard_conversion (tree, tree, tree, bool, int);
193 static conversion *reference_binding (tree, tree, tree, bool, int);
194 static conversion *build_conv (conversion_kind, tree, conversion *);
195 static conversion *build_list_conv (tree, tree, int);
196 static bool is_subseq (conversion *, conversion *);
197 static conversion *maybe_handle_ref_bind (conversion **);
198 static void maybe_handle_implicit_object (conversion **);
199 static struct z_candidate *add_candidate
200 (struct z_candidate **, tree, tree, const VEC(tree,gc) *, size_t,
201 conversion **, tree, tree, int, struct rejection_reason *);
202 static tree source_type (conversion *);
203 static void add_warning (struct z_candidate *, struct z_candidate *);
204 static bool reference_compatible_p (tree, tree);
205 static conversion *convert_class_to_reference (tree, tree, tree, int);
206 static conversion *direct_reference_binding (tree, conversion *);
207 static bool promoted_arithmetic_type_p (tree);
208 static conversion *conditional_conversion (tree, tree);
209 static char *name_as_c_string (tree, tree, bool *);
210 static tree prep_operand (tree);
211 static void add_candidates (tree, tree, const VEC(tree,gc) *, tree, tree, bool,
212 tree, tree, int, struct z_candidate **);
213 static conversion *merge_conversion_sequences (conversion *, conversion *);
214 static bool magic_varargs_p (tree);
215 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
217 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
218 NAME can take many forms... */
221 check_dtor_name (tree basetype, tree name)
223 /* Just accept something we've already complained about. */
224 if (name == error_mark_node)
227 if (TREE_CODE (name) == TYPE_DECL)
228 name = TREE_TYPE (name);
229 else if (TYPE_P (name))
231 else if (TREE_CODE (name) == IDENTIFIER_NODE)
233 if ((MAYBE_CLASS_TYPE_P (basetype)
234 && name == constructor_name (basetype))
235 || (TREE_CODE (basetype) == ENUMERAL_TYPE
236 && name == TYPE_IDENTIFIER (basetype)))
239 name = get_type_value (name);
245 template <class T> struct S { ~S(); };
249 NAME will be a class template. */
250 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
254 if (!name || name == error_mark_node)
256 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
259 /* We want the address of a function or method. We avoid creating a
260 pointer-to-member function. */
263 build_addr_func (tree function)
265 tree type = TREE_TYPE (function);
267 /* We have to do these by hand to avoid real pointer to member
269 if (TREE_CODE (type) == METHOD_TYPE)
271 if (TREE_CODE (function) == OFFSET_REF)
273 tree object = build_address (TREE_OPERAND (function, 0));
274 return get_member_function_from_ptrfunc (&object,
275 TREE_OPERAND (function, 1));
277 function = build_address (function);
280 function = decay_conversion (function);
285 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
286 POINTER_TYPE to those. Note, pointer to member function types
287 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
288 two variants. build_call_a is the primitive taking an array of
289 arguments, while build_call_n is a wrapper that handles varargs. */
292 build_call_n (tree function, int n, ...)
295 return build_call_a (function, 0, NULL);
298 tree *argarray = XALLOCAVEC (tree, n);
303 for (i = 0; i < n; i++)
304 argarray[i] = va_arg (ap, tree);
306 return build_call_a (function, n, argarray);
311 build_call_a (tree function, int n, tree *argarray)
313 int is_constructor = 0;
320 function = build_addr_func (function);
322 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
323 fntype = TREE_TYPE (TREE_TYPE (function));
324 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
325 || TREE_CODE (fntype) == METHOD_TYPE);
326 result_type = TREE_TYPE (fntype);
327 /* An rvalue has no cv-qualifiers. */
328 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
329 result_type = cv_unqualified (result_type);
331 if (TREE_CODE (function) == ADDR_EXPR
332 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
334 decl = TREE_OPERAND (function, 0);
335 if (!TREE_USED (decl))
337 /* We invoke build_call directly for several library
338 functions. These may have been declared normally if
339 we're building libgcc, so we can't just check
341 gcc_assert (DECL_ARTIFICIAL (decl)
342 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
350 /* We check both the decl and the type; a function may be known not to
351 throw without being declared throw(). */
352 nothrow = ((decl && TREE_NOTHROW (decl))
353 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
355 if (!nothrow && cfun && cp_function_chain)
356 cp_function_chain->can_throw = 1;
358 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
359 current_function_returns_abnormally = 1;
361 if (decl && TREE_DEPRECATED (decl))
362 warn_deprecated_use (decl, NULL_TREE);
363 require_complete_eh_spec_types (fntype, decl);
365 if (decl && DECL_CONSTRUCTOR_P (decl))
368 /* Don't pass empty class objects by value. This is useful
369 for tags in STL, which are used to control overload resolution.
370 We don't need to handle other cases of copying empty classes. */
371 if (! decl || ! DECL_BUILT_IN (decl))
372 for (i = 0; i < n; i++)
373 if (is_empty_class (TREE_TYPE (argarray[i]))
374 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
376 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
377 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
381 function = build_call_array_loc (input_location,
382 result_type, function, n, argarray);
383 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
384 TREE_NOTHROW (function) = nothrow;
389 /* Build something of the form ptr->method (args)
390 or object.method (args). This can also build
391 calls to constructors, and find friends.
393 Member functions always take their class variable
396 INSTANCE is a class instance.
398 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
400 PARMS help to figure out what that NAME really refers to.
402 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
403 down to the real instance type to use for access checking. We need this
404 information to get protected accesses correct.
406 FLAGS is the logical disjunction of zero or more LOOKUP_
407 flags. See cp-tree.h for more info.
409 If this is all OK, calls build_function_call with the resolved
412 This function must also handle being called to perform
413 initialization, promotion/coercion of arguments, and
414 instantiation of default parameters.
416 Note that NAME may refer to an instance variable name. If
417 `operator()()' is defined for the type of that field, then we return
420 /* New overloading code. */
422 typedef struct z_candidate z_candidate;
424 typedef struct candidate_warning candidate_warning;
425 struct candidate_warning {
427 candidate_warning *next;
430 /* Information for providing diagnostics about why overloading failed. */
432 enum rejection_reason_code {
435 rr_explicit_conversion,
437 rr_bad_arg_conversion
440 struct conversion_info {
441 /* The index of the argument, 0-based. */
443 /* The type of the actual argument. */
445 /* The type of the formal argument. */
449 struct rejection_reason {
450 enum rejection_reason_code code;
452 /* Information about an arity mismatch. */
454 /* The expected number of arguments. */
456 /* The actual number of arguments in the call. */
458 /* Whether the call was a varargs call. */
461 /* Information about an argument conversion mismatch. */
462 struct conversion_info conversion;
463 /* Same, but for bad argument conversions. */
464 struct conversion_info bad_conversion;
469 /* The FUNCTION_DECL that will be called if this candidate is
470 selected by overload resolution. */
472 /* If not NULL_TREE, the first argument to use when calling this
475 /* The rest of the arguments to use when calling this function. If
476 there are no further arguments this may be NULL or it may be an
478 const VEC(tree,gc) *args;
479 /* The implicit conversion sequences for each of the arguments to
482 /* The number of implicit conversion sequences. */
484 /* If FN is a user-defined conversion, the standard conversion
485 sequence from the type returned by FN to the desired destination
487 conversion *second_conv;
489 struct rejection_reason *reason;
490 /* If FN is a member function, the binfo indicating the path used to
491 qualify the name of FN at the call site. This path is used to
492 determine whether or not FN is accessible if it is selected by
493 overload resolution. The DECL_CONTEXT of FN will always be a
494 (possibly improper) base of this binfo. */
496 /* If FN is a non-static member function, the binfo indicating the
497 subobject to which the `this' pointer should be converted if FN
498 is selected by overload resolution. The type pointed to the by
499 the `this' pointer must correspond to the most derived class
500 indicated by the CONVERSION_PATH. */
501 tree conversion_path;
504 candidate_warning *warnings;
508 /* Returns true iff T is a null pointer constant in the sense of
512 null_ptr_cst_p (tree t)
516 A null pointer constant is an integral constant expression
517 (_expr.const_) rvalue of integer type that evaluates to zero or
518 an rvalue of type std::nullptr_t. */
519 if (NULLPTR_TYPE_P (TREE_TYPE (t)))
521 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)))
523 if (cxx_dialect >= cxx0x)
525 t = fold_non_dependent_expr (t);
526 t = maybe_constant_value (t);
527 if (TREE_CONSTANT (t) && integer_zerop (t))
532 t = integral_constant_value (t);
534 if (integer_zerop (t) && !TREE_OVERFLOW (t))
541 /* Returns nonzero if PARMLIST consists of only default parms,
542 ellipsis, and/or undeduced parameter packs. */
545 sufficient_parms_p (const_tree parmlist)
547 for (; parmlist && parmlist != void_list_node;
548 parmlist = TREE_CHAIN (parmlist))
549 if (!TREE_PURPOSE (parmlist)
550 && !PACK_EXPANSION_P (TREE_VALUE (parmlist)))
555 /* Allocate N bytes of memory from the conversion obstack. The memory
556 is zeroed before being returned. */
559 conversion_obstack_alloc (size_t n)
562 if (!conversion_obstack_initialized)
564 gcc_obstack_init (&conversion_obstack);
565 conversion_obstack_initialized = true;
567 p = obstack_alloc (&conversion_obstack, n);
572 /* Allocate rejection reasons. */
574 static struct rejection_reason *
575 alloc_rejection (enum rejection_reason_code code)
577 struct rejection_reason *p;
578 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
583 static struct rejection_reason *
584 arity_rejection (tree first_arg, int expected, int actual)
586 struct rejection_reason *r = alloc_rejection (rr_arity);
587 int adjust = first_arg != NULL_TREE;
588 r->u.arity.expected = expected - adjust;
589 r->u.arity.actual = actual - adjust;
593 static struct rejection_reason *
594 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
596 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
597 int adjust = first_arg != NULL_TREE;
598 r->u.conversion.n_arg = n_arg - adjust;
599 r->u.conversion.from_type = from;
600 r->u.conversion.to_type = to;
604 static struct rejection_reason *
605 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
607 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
608 int adjust = first_arg != NULL_TREE;
609 r->u.bad_conversion.n_arg = n_arg - adjust;
610 r->u.bad_conversion.from_type = from;
611 r->u.bad_conversion.to_type = to;
615 static struct rejection_reason *
616 explicit_conversion_rejection (tree from, tree to)
618 struct rejection_reason *r = alloc_rejection (rr_explicit_conversion);
619 r->u.conversion.n_arg = 0;
620 r->u.conversion.from_type = from;
621 r->u.conversion.to_type = to;
625 /* Dynamically allocate a conversion. */
628 alloc_conversion (conversion_kind kind)
631 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
636 #ifdef ENABLE_CHECKING
638 /* Make sure that all memory on the conversion obstack has been
642 validate_conversion_obstack (void)
644 if (conversion_obstack_initialized)
645 gcc_assert ((obstack_next_free (&conversion_obstack)
646 == obstack_base (&conversion_obstack)));
649 #endif /* ENABLE_CHECKING */
651 /* Dynamically allocate an array of N conversions. */
654 alloc_conversions (size_t n)
656 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
660 build_conv (conversion_kind code, tree type, conversion *from)
663 conversion_rank rank = CONVERSION_RANK (from);
665 /* Note that the caller is responsible for filling in t->cand for
666 user-defined conversions. */
667 t = alloc_conversion (code);
690 t->user_conv_p = (code == ck_user || from->user_conv_p);
691 t->bad_p = from->bad_p;
696 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
697 specialization of std::initializer_list<T>, if such a conversion is
701 build_list_conv (tree type, tree ctor, int flags)
703 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
704 unsigned len = CONSTRUCTOR_NELTS (ctor);
705 conversion **subconvs = alloc_conversions (len);
710 /* Within a list-initialization we can have more user-defined
712 flags &= ~LOOKUP_NO_CONVERSION;
713 /* But no narrowing conversions. */
714 flags |= LOOKUP_NO_NARROWING;
716 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
719 = implicit_conversion (elttype, TREE_TYPE (val), val,
727 t = alloc_conversion (ck_list);
729 t->u.list = subconvs;
732 for (i = 0; i < len; ++i)
734 conversion *sub = subconvs[i];
735 if (sub->rank > t->rank)
737 if (sub->user_conv_p)
738 t->user_conv_p = true;
746 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
747 is a valid aggregate initializer for array type ATYPE. */
750 can_convert_array (tree atype, tree ctor, int flags)
753 tree elttype = TREE_TYPE (atype);
754 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
756 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
758 if (TREE_CODE (elttype) == ARRAY_TYPE
759 && TREE_CODE (val) == CONSTRUCTOR)
760 ok = can_convert_array (elttype, val, flags);
762 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags);
769 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
770 aggregate class, if such a conversion is possible. */
773 build_aggr_conv (tree type, tree ctor, int flags)
775 unsigned HOST_WIDE_INT i = 0;
777 tree field = next_initializable_field (TYPE_FIELDS (type));
778 tree empty_ctor = NULL_TREE;
780 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
782 tree ftype = TREE_TYPE (field);
786 if (i < CONSTRUCTOR_NELTS (ctor))
787 val = CONSTRUCTOR_ELT (ctor, i)->value;
790 if (empty_ctor == NULL_TREE)
791 empty_ctor = build_constructor (init_list_type_node, NULL);
796 if (TREE_CODE (ftype) == ARRAY_TYPE
797 && TREE_CODE (val) == CONSTRUCTOR)
798 ok = can_convert_array (ftype, val, flags);
800 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags);
805 if (TREE_CODE (type) == UNION_TYPE)
809 if (i < CONSTRUCTOR_NELTS (ctor))
812 c = alloc_conversion (ck_aggr);
815 c->user_conv_p = true;
820 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
821 array type, if such a conversion is possible. */
824 build_array_conv (tree type, tree ctor, int flags)
827 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
828 tree elttype = TREE_TYPE (type);
833 enum conversion_rank rank = cr_exact;
835 if (TYPE_DOMAIN (type))
837 unsigned HOST_WIDE_INT alen = tree_low_cst (array_type_nelts_top (type), 1);
842 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
845 = implicit_conversion (elttype, TREE_TYPE (val), val,
850 if (sub->rank > rank)
852 if (sub->user_conv_p)
858 c = alloc_conversion (ck_aggr);
861 c->user_conv_p = user;
867 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
868 complex type, if such a conversion is possible. */
871 build_complex_conv (tree type, tree ctor, int flags)
874 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
875 tree elttype = TREE_TYPE (type);
880 enum conversion_rank rank = cr_exact;
885 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
888 = implicit_conversion (elttype, TREE_TYPE (val), val,
893 if (sub->rank > rank)
895 if (sub->user_conv_p)
901 c = alloc_conversion (ck_aggr);
904 c->user_conv_p = user;
910 /* Build a representation of the identity conversion from EXPR to
911 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
914 build_identity_conv (tree type, tree expr)
918 c = alloc_conversion (ck_identity);
925 /* Converting from EXPR to TYPE was ambiguous in the sense that there
926 were multiple user-defined conversions to accomplish the job.
927 Build a conversion that indicates that ambiguity. */
930 build_ambiguous_conv (tree type, tree expr)
934 c = alloc_conversion (ck_ambig);
942 strip_top_quals (tree t)
944 if (TREE_CODE (t) == ARRAY_TYPE)
946 return cp_build_qualified_type (t, 0);
949 /* Returns the standard conversion path (see [conv]) from type FROM to type
950 TO, if any. For proper handling of null pointer constants, you must
951 also pass the expression EXPR to convert from. If C_CAST_P is true,
952 this conversion is coming from a C-style cast. */
955 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
958 enum tree_code fcode, tcode;
960 bool fromref = false;
963 to = non_reference (to);
964 if (TREE_CODE (from) == REFERENCE_TYPE)
967 from = TREE_TYPE (from);
970 to = strip_top_quals (to);
971 from = strip_top_quals (from);
973 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
974 && expr && type_unknown_p (expr))
976 tsubst_flags_t tflags = tf_conv;
977 if (!(flags & LOOKUP_PROTECT))
978 tflags |= tf_no_access_control;
979 expr = instantiate_type (to, expr, tflags);
980 if (expr == error_mark_node)
982 from = TREE_TYPE (expr);
985 fcode = TREE_CODE (from);
986 tcode = TREE_CODE (to);
988 conv = build_identity_conv (from, expr);
989 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
991 from = type_decays_to (from);
992 fcode = TREE_CODE (from);
993 conv = build_conv (ck_lvalue, from, conv);
995 else if (fromref || (expr && lvalue_p (expr)))
1000 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
1003 from = strip_top_quals (bitfield_type);
1004 fcode = TREE_CODE (from);
1007 conv = build_conv (ck_rvalue, from, conv);
1008 if (flags & LOOKUP_PREFER_RVALUE)
1009 conv->rvaluedness_matches_p = true;
1012 /* Allow conversion between `__complex__' data types. */
1013 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
1015 /* The standard conversion sequence to convert FROM to TO is
1016 the standard conversion sequence to perform componentwise
1018 conversion *part_conv = standard_conversion
1019 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
1023 conv = build_conv (part_conv->kind, to, conv);
1024 conv->rank = part_conv->rank;
1032 if (same_type_p (from, to))
1034 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
1035 conv->type = qualified_to;
1040 A null pointer constant can be converted to a pointer type; ... A
1041 null pointer constant of integral type can be converted to an
1042 rvalue of type std::nullptr_t. */
1043 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to)
1044 || NULLPTR_TYPE_P (to))
1045 && expr && null_ptr_cst_p (expr))
1046 conv = build_conv (ck_std, to, conv);
1047 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
1048 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
1050 /* For backwards brain damage compatibility, allow interconversion of
1051 pointers and integers with a pedwarn. */
1052 conv = build_conv (ck_std, to, conv);
1055 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
1057 /* For backwards brain damage compatibility, allow interconversion of
1058 enums and integers with a pedwarn. */
1059 conv = build_conv (ck_std, to, conv);
1062 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1063 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
1068 if (tcode == POINTER_TYPE
1069 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
1072 else if (VOID_TYPE_P (TREE_TYPE (to))
1073 && !TYPE_PTRMEM_P (from)
1074 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
1076 tree nfrom = TREE_TYPE (from);
1077 from = build_pointer_type
1078 (cp_build_qualified_type (void_type_node,
1079 cp_type_quals (nfrom)));
1080 conv = build_conv (ck_ptr, from, conv);
1082 else if (TYPE_PTRMEM_P (from))
1084 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1085 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1087 if (DERIVED_FROM_P (fbase, tbase)
1088 && (same_type_ignoring_top_level_qualifiers_p
1089 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
1090 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
1092 from = build_ptrmem_type (tbase,
1093 TYPE_PTRMEM_POINTED_TO_TYPE (from));
1094 conv = build_conv (ck_pmem, from, conv);
1096 else if (!same_type_p (fbase, tbase))
1099 else if (CLASS_TYPE_P (TREE_TYPE (from))
1100 && CLASS_TYPE_P (TREE_TYPE (to))
1103 An rvalue of type "pointer to cv D," where D is a
1104 class type, can be converted to an rvalue of type
1105 "pointer to cv B," where B is a base class (clause
1106 _class.derived_) of D. If B is an inaccessible
1107 (clause _class.access_) or ambiguous
1108 (_class.member.lookup_) base class of D, a program
1109 that necessitates this conversion is ill-formed.
1110 Therefore, we use DERIVED_FROM_P, and do not check
1111 access or uniqueness. */
1112 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
1115 cp_build_qualified_type (TREE_TYPE (to),
1116 cp_type_quals (TREE_TYPE (from)));
1117 from = build_pointer_type (from);
1118 conv = build_conv (ck_ptr, from, conv);
1119 conv->base_p = true;
1122 if (tcode == POINTER_TYPE)
1124 to_pointee = TREE_TYPE (to);
1125 from_pointee = TREE_TYPE (from);
1129 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1130 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1133 if (same_type_p (from, to))
1135 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1136 /* In a C-style cast, we ignore CV-qualification because we
1137 are allowed to perform a static_cast followed by a
1139 conv = build_conv (ck_qual, to, conv);
1140 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1141 conv = build_conv (ck_qual, to, conv);
1142 else if (expr && string_conv_p (to, expr, 0))
1143 /* converting from string constant to char *. */
1144 conv = build_conv (ck_qual, to, conv);
1145 /* Allow conversions among compatible ObjC pointer types (base
1146 conversions have been already handled above). */
1147 else if (c_dialect_objc ()
1148 && objc_compare_types (to, from, -4, NULL_TREE))
1149 conv = build_conv (ck_ptr, to, conv);
1150 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1152 conv = build_conv (ck_ptr, to, conv);
1160 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1162 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1163 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1164 tree fbase = class_of_this_parm (fromfn);
1165 tree tbase = class_of_this_parm (tofn);
1167 if (!DERIVED_FROM_P (fbase, tbase)
1168 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
1169 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
1170 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
1171 || cp_type_quals (fbase) != cp_type_quals (tbase))
1174 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase));
1175 from = build_ptrmemfunc_type (build_pointer_type (from));
1176 conv = build_conv (ck_pmem, from, conv);
1177 conv->base_p = true;
1179 else if (tcode == BOOLEAN_TYPE)
1183 An rvalue of arithmetic, unscoped enumeration, pointer, or
1184 pointer to member type can be converted to an rvalue of type
1185 bool. ... An rvalue of type std::nullptr_t can be converted
1186 to an rvalue of type bool; */
1187 if (ARITHMETIC_TYPE_P (from)
1188 || UNSCOPED_ENUM_P (from)
1189 || fcode == POINTER_TYPE
1190 || TYPE_PTR_TO_MEMBER_P (from)
1191 || NULLPTR_TYPE_P (from))
1193 conv = build_conv (ck_std, to, conv);
1194 if (fcode == POINTER_TYPE
1195 || TYPE_PTRMEM_P (from)
1196 || (TYPE_PTRMEMFUNC_P (from)
1197 && conv->rank < cr_pbool)
1198 || NULLPTR_TYPE_P (from))
1199 conv->rank = cr_pbool;
1205 /* We don't check for ENUMERAL_TYPE here because there are no standard
1206 conversions to enum type. */
1207 /* As an extension, allow conversion to complex type. */
1208 else if (ARITHMETIC_TYPE_P (to))
1210 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
1211 || SCOPED_ENUM_P (from))
1213 conv = build_conv (ck_std, to, conv);
1215 /* Give this a better rank if it's a promotion. */
1216 if (same_type_p (to, type_promotes_to (from))
1217 && conv->u.next->rank <= cr_promotion)
1218 conv->rank = cr_promotion;
1220 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1221 && vector_types_convertible_p (from, to, false))
1222 return build_conv (ck_std, to, conv);
1223 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1224 && is_properly_derived_from (from, to))
1226 if (conv->kind == ck_rvalue)
1227 conv = conv->u.next;
1228 conv = build_conv (ck_base, to, conv);
1229 /* The derived-to-base conversion indicates the initialization
1230 of a parameter with base type from an object of a derived
1231 type. A temporary object is created to hold the result of
1232 the conversion unless we're binding directly to a reference. */
1233 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1238 if (flags & LOOKUP_NO_NARROWING)
1239 conv->check_narrowing = true;
1244 /* Returns nonzero if T1 is reference-related to T2. */
1247 reference_related_p (tree t1, tree t2)
1249 if (t1 == error_mark_node || t2 == error_mark_node)
1252 t1 = TYPE_MAIN_VARIANT (t1);
1253 t2 = TYPE_MAIN_VARIANT (t2);
1257 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1258 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1260 return (same_type_p (t1, t2)
1261 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1262 && DERIVED_FROM_P (t1, t2)));
1265 /* Returns nonzero if T1 is reference-compatible with T2. */
1268 reference_compatible_p (tree t1, tree t2)
1272 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1273 reference-related to T2 and cv1 is the same cv-qualification as,
1274 or greater cv-qualification than, cv2. */
1275 return (reference_related_p (t1, t2)
1276 && at_least_as_qualified_p (t1, t2));
1279 /* Determine whether or not the EXPR (of class type S) can be
1280 converted to T as in [over.match.ref]. */
1283 convert_class_to_reference_1 (tree reference_type, tree s, tree expr, int flags)
1289 struct z_candidate *candidates;
1290 struct z_candidate *cand;
1296 conversions = lookup_conversions (s);
1302 Assuming that "cv1 T" is the underlying type of the reference
1303 being initialized, and "cv S" is the type of the initializer
1304 expression, with S a class type, the candidate functions are
1305 selected as follows:
1307 --The conversion functions of S and its base classes are
1308 considered. Those that are not hidden within S and yield type
1309 "reference to cv2 T2", where "cv1 T" is reference-compatible
1310 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1312 The argument list has one argument, which is the initializer
1317 /* Conceptually, we should take the address of EXPR and put it in
1318 the argument list. Unfortunately, however, that can result in
1319 error messages, which we should not issue now because we are just
1320 trying to find a conversion operator. Therefore, we use NULL,
1321 cast to the appropriate type. */
1322 first_arg = build_int_cst (build_pointer_type (s), 0);
1324 t = TREE_TYPE (reference_type);
1326 /* We're performing a user-defined conversion to a desired type, so set
1327 this for the benefit of add_candidates. */
1328 flags |= LOOKUP_NO_CONVERSION;
1330 for (; conversions; conversions = TREE_CHAIN (conversions))
1332 tree fns = TREE_VALUE (conversions);
1333 tree binfo = TREE_PURPOSE (conversions);
1334 struct z_candidate *old_candidates = candidates;;
1336 add_candidates (fns, first_arg, NULL, reference_type,
1338 binfo, TYPE_BINFO (s),
1339 flags, &candidates);
1341 for (cand = candidates; cand != old_candidates; cand = cand->next)
1343 /* Now, see if the conversion function really returns
1344 an lvalue of the appropriate type. From the
1345 point of view of unification, simply returning an
1346 rvalue of the right type is good enough. */
1348 tree t2 = TREE_TYPE (TREE_TYPE (f));
1349 if (cand->viable == 0)
1350 /* Don't bother looking more closely. */;
1351 else if (TREE_CODE (t2) != REFERENCE_TYPE
1352 || !reference_compatible_p (t, TREE_TYPE (t2)))
1354 /* No need to set cand->reason here; this is most likely
1355 an ambiguous match. If it's not, either this candidate
1356 will win, or we will have identified a reason for it
1362 conversion *identity_conv;
1363 /* Build a standard conversion sequence indicating the
1364 binding from the reference type returned by the
1365 function to the desired REFERENCE_TYPE. */
1367 = build_identity_conv (TREE_TYPE (TREE_TYPE
1368 (TREE_TYPE (cand->fn))),
1371 = (direct_reference_binding
1372 (reference_type, identity_conv));
1373 cand->second_conv->rvaluedness_matches_p
1374 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1375 == TYPE_REF_IS_RVALUE (reference_type);
1376 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1378 /* Don't allow binding of lvalues to rvalue references. */
1379 if (TYPE_REF_IS_RVALUE (reference_type)
1380 /* Function lvalues are OK, though. */
1381 && TREE_CODE (TREE_TYPE (reference_type)) != FUNCTION_TYPE
1382 && !TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn))))
1383 cand->second_conv->bad_p = true;
1388 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1389 /* If none of the conversion functions worked out, let our caller
1394 cand = tourney (candidates);
1398 /* Now that we know that this is the function we're going to use fix
1399 the dummy first argument. */
1400 gcc_assert (cand->first_arg == NULL_TREE
1401 || integer_zerop (cand->first_arg));
1402 cand->first_arg = build_this (expr);
1404 /* Build a user-defined conversion sequence representing the
1406 conv = build_conv (ck_user,
1407 TREE_TYPE (TREE_TYPE (cand->fn)),
1408 build_identity_conv (TREE_TYPE (expr), expr));
1411 if (cand->viable == -1)
1414 /* Merge it with the standard conversion sequence from the
1415 conversion function's return type to the desired type. */
1416 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1418 return cand->second_conv;
1421 /* Wrapper for above. */
1424 convert_class_to_reference (tree reference_type, tree s, tree expr, int flags)
1427 bool subtime = timevar_cond_start (TV_OVERLOAD);
1428 ret = convert_class_to_reference_1 (reference_type, s, expr, flags);
1429 timevar_cond_stop (TV_OVERLOAD, subtime);
1433 /* A reference of the indicated TYPE is being bound directly to the
1434 expression represented by the implicit conversion sequence CONV.
1435 Return a conversion sequence for this binding. */
1438 direct_reference_binding (tree type, conversion *conv)
1442 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1443 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1445 t = TREE_TYPE (type);
1449 When a parameter of reference type binds directly
1450 (_dcl.init.ref_) to an argument expression, the implicit
1451 conversion sequence is the identity conversion, unless the
1452 argument expression has a type that is a derived class of the
1453 parameter type, in which case the implicit conversion sequence is
1454 a derived-to-base Conversion.
1456 If the parameter binds directly to the result of applying a
1457 conversion function to the argument expression, the implicit
1458 conversion sequence is a user-defined conversion sequence
1459 (_over.ics.user_), with the second standard conversion sequence
1460 either an identity conversion or, if the conversion function
1461 returns an entity of a type that is a derived class of the
1462 parameter type, a derived-to-base conversion. */
1463 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1465 /* Represent the derived-to-base conversion. */
1466 conv = build_conv (ck_base, t, conv);
1467 /* We will actually be binding to the base-class subobject in
1468 the derived class, so we mark this conversion appropriately.
1469 That way, convert_like knows not to generate a temporary. */
1470 conv->need_temporary_p = false;
1472 return build_conv (ck_ref_bind, type, conv);
1475 /* Returns the conversion path from type FROM to reference type TO for
1476 purposes of reference binding. For lvalue binding, either pass a
1477 reference type to FROM or an lvalue expression to EXPR. If the
1478 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1479 the conversion returned. If C_CAST_P is true, this
1480 conversion is coming from a C-style cast. */
1483 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1485 conversion *conv = NULL;
1486 tree to = TREE_TYPE (rto);
1491 cp_lvalue_kind is_lvalue = clk_none;
1493 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1495 expr = instantiate_type (to, expr, tf_none);
1496 if (expr == error_mark_node)
1498 from = TREE_TYPE (expr);
1501 if (TREE_CODE (from) == REFERENCE_TYPE)
1503 /* Anything with reference type is an lvalue. */
1504 is_lvalue = clk_ordinary;
1505 from = TREE_TYPE (from);
1508 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1510 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1511 conv = implicit_conversion (to, from, expr, c_cast_p,
1513 if (!CLASS_TYPE_P (to)
1514 && CONSTRUCTOR_NELTS (expr) == 1)
1516 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1517 if (error_operand_p (expr))
1519 from = TREE_TYPE (expr);
1523 if (is_lvalue == clk_none && expr)
1524 is_lvalue = real_lvalue_p (expr);
1527 if ((is_lvalue & clk_bitfield) != 0)
1528 tfrom = unlowered_expr_type (expr);
1530 /* Figure out whether or not the types are reference-related and
1531 reference compatible. We have do do this after stripping
1532 references from FROM. */
1533 related_p = reference_related_p (to, tfrom);
1534 /* If this is a C cast, first convert to an appropriately qualified
1535 type, so that we can later do a const_cast to the desired type. */
1536 if (related_p && c_cast_p
1537 && !at_least_as_qualified_p (to, tfrom))
1538 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1539 compatible_p = reference_compatible_p (to, tfrom);
1541 /* Directly bind reference when target expression's type is compatible with
1542 the reference and expression is an lvalue. In DR391, the wording in
1543 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1544 const and rvalue references to rvalues of compatible class type.
1545 We should also do direct bindings for non-class "rvalues" derived from
1546 rvalue references. */
1549 || (((CP_TYPE_CONST_NON_VOLATILE_P (to)
1550 && !(flags & LOOKUP_NO_TEMP_BIND))
1551 || TYPE_REF_IS_RVALUE (rto))
1552 && (CLASS_TYPE_P (from)
1553 || TREE_CODE (from) == ARRAY_TYPE
1554 || (expr && lvalue_p (expr))))))
1558 If the initializer expression
1560 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1561 is reference-compatible with "cv2 T2,"
1563 the reference is bound directly to the initializer expression
1567 If the initializer expression is an rvalue, with T2 a class type,
1568 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1569 is bound to the object represented by the rvalue or to a sub-object
1570 within that object. */
1572 conv = build_identity_conv (tfrom, expr);
1573 conv = direct_reference_binding (rto, conv);
1575 if (flags & LOOKUP_PREFER_RVALUE)
1576 /* The top-level caller requested that we pretend that the lvalue
1577 be treated as an rvalue. */
1578 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1580 conv->rvaluedness_matches_p
1581 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1583 if ((is_lvalue & clk_bitfield) != 0
1584 || ((is_lvalue & clk_packed) != 0 && !TYPE_PACKED (to)))
1585 /* For the purposes of overload resolution, we ignore the fact
1586 this expression is a bitfield or packed field. (In particular,
1587 [over.ics.ref] says specifically that a function with a
1588 non-const reference parameter is viable even if the
1589 argument is a bitfield.)
1591 However, when we actually call the function we must create
1592 a temporary to which to bind the reference. If the
1593 reference is volatile, or isn't const, then we cannot make
1594 a temporary, so we just issue an error when the conversion
1596 conv->need_temporary_p = true;
1598 /* Don't allow binding of lvalues (other than function lvalues) to
1599 rvalue references. */
1600 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1601 && TREE_CODE (to) != FUNCTION_TYPE
1602 && !(flags & LOOKUP_PREFER_RVALUE))
1607 /* [class.conv.fct] A conversion function is never used to convert a
1608 (possibly cv-qualified) object to the (possibly cv-qualified) same
1609 object type (or a reference to it), to a (possibly cv-qualified) base
1610 class of that type (or a reference to it).... */
1611 else if (CLASS_TYPE_P (from) && !related_p
1612 && !(flags & LOOKUP_NO_CONVERSION))
1616 If the initializer expression
1618 -- has a class type (i.e., T2 is a class type) can be
1619 implicitly converted to an lvalue of type "cv3 T3," where
1620 "cv1 T1" is reference-compatible with "cv3 T3". (this
1621 conversion is selected by enumerating the applicable
1622 conversion functions (_over.match.ref_) and choosing the
1623 best one through overload resolution. (_over.match_).
1625 the reference is bound to the lvalue result of the conversion
1626 in the second case. */
1627 conv = convert_class_to_reference (rto, from, expr, flags);
1632 /* From this point on, we conceptually need temporaries, even if we
1633 elide them. Only the cases above are "direct bindings". */
1634 if (flags & LOOKUP_NO_TEMP_BIND)
1639 When a parameter of reference type is not bound directly to an
1640 argument expression, the conversion sequence is the one required
1641 to convert the argument expression to the underlying type of the
1642 reference according to _over.best.ics_. Conceptually, this
1643 conversion sequence corresponds to copy-initializing a temporary
1644 of the underlying type with the argument expression. Any
1645 difference in top-level cv-qualification is subsumed by the
1646 initialization itself and does not constitute a conversion. */
1650 Otherwise, the reference shall be to a non-volatile const type.
1652 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1653 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1658 Otherwise, a temporary of type "cv1 T1" is created and
1659 initialized from the initializer expression using the rules for a
1660 non-reference copy initialization. If T1 is reference-related to
1661 T2, cv1 must be the same cv-qualification as, or greater
1662 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1663 if (related_p && !at_least_as_qualified_p (to, from))
1666 /* We're generating a temporary now, but don't bind any more in the
1667 conversion (specifically, don't slice the temporary returned by a
1668 conversion operator). */
1669 flags |= LOOKUP_NO_TEMP_BIND;
1671 /* Core issue 899: When [copy-]initializing a temporary to be bound
1672 to the first parameter of a copy constructor (12.8) called with
1673 a single argument in the context of direct-initialization,
1674 explicit conversion functions are also considered.
1676 So don't set LOOKUP_ONLYCONVERTING in that case. */
1677 if (!(flags & LOOKUP_COPY_PARM))
1678 flags |= LOOKUP_ONLYCONVERTING;
1681 conv = implicit_conversion (to, from, expr, c_cast_p,
1686 conv = build_conv (ck_ref_bind, rto, conv);
1687 /* This reference binding, unlike those above, requires the
1688 creation of a temporary. */
1689 conv->need_temporary_p = true;
1690 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1695 /* Returns the implicit conversion sequence (see [over.ics]) from type
1696 FROM to type TO. The optional expression EXPR may affect the
1697 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1698 true, this conversion is coming from a C-style cast. */
1701 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1706 if (from == error_mark_node || to == error_mark_node
1707 || expr == error_mark_node)
1710 if (TREE_CODE (to) == REFERENCE_TYPE)
1711 conv = reference_binding (to, from, expr, c_cast_p, flags);
1713 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1718 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1720 if (is_std_init_list (to))
1721 return build_list_conv (to, expr, flags);
1723 /* As an extension, allow list-initialization of _Complex. */
1724 if (TREE_CODE (to) == COMPLEX_TYPE)
1726 conv = build_complex_conv (to, expr, flags);
1731 /* Allow conversion from an initializer-list with one element to a
1733 if (SCALAR_TYPE_P (to))
1735 int nelts = CONSTRUCTOR_NELTS (expr);
1739 elt = build_value_init (to, tf_none);
1740 else if (nelts == 1)
1741 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1743 elt = error_mark_node;
1745 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1749 conv->check_narrowing = true;
1750 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1751 /* Too many levels of braces, i.e. '{{1}}'. */
1756 else if (TREE_CODE (to) == ARRAY_TYPE)
1757 return build_array_conv (to, expr, flags);
1760 if (expr != NULL_TREE
1761 && (MAYBE_CLASS_TYPE_P (from)
1762 || MAYBE_CLASS_TYPE_P (to))
1763 && (flags & LOOKUP_NO_CONVERSION) == 0)
1765 struct z_candidate *cand;
1766 int convflags = (flags & (LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING
1767 |LOOKUP_NO_NARROWING));
1769 if (CLASS_TYPE_P (to)
1770 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1771 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1772 return build_aggr_conv (to, expr, flags);
1774 cand = build_user_type_conversion_1 (to, expr, convflags);
1776 conv = cand->second_conv;
1778 /* We used to try to bind a reference to a temporary here, but that
1779 is now handled after the recursive call to this function at the end
1780 of reference_binding. */
1787 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1788 functions. ARGS will not be changed until a single candidate is
1791 static struct z_candidate *
1792 add_candidate (struct z_candidate **candidates,
1793 tree fn, tree first_arg, const VEC(tree,gc) *args,
1794 size_t num_convs, conversion **convs,
1795 tree access_path, tree conversion_path,
1796 int viable, struct rejection_reason *reason)
1798 struct z_candidate *cand = (struct z_candidate *)
1799 conversion_obstack_alloc (sizeof (struct z_candidate));
1802 cand->first_arg = first_arg;
1804 cand->convs = convs;
1805 cand->num_convs = num_convs;
1806 cand->access_path = access_path;
1807 cand->conversion_path = conversion_path;
1808 cand->viable = viable;
1809 cand->reason = reason;
1810 cand->next = *candidates;
1816 /* Return the number of remaining arguments in the parameter list
1817 beginning with ARG. */
1820 remaining_arguments (tree arg)
1824 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1825 arg = TREE_CHAIN (arg))
1831 /* Create an overload candidate for the function or method FN called
1832 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1833 FLAGS is passed on to implicit_conversion.
1835 This does not change ARGS.
1837 CTYPE, if non-NULL, is the type we want to pretend this function
1838 comes from for purposes of overload resolution. */
1840 static struct z_candidate *
1841 add_function_candidate (struct z_candidate **candidates,
1842 tree fn, tree ctype, tree first_arg,
1843 const VEC(tree,gc) *args, tree access_path,
1844 tree conversion_path, int flags)
1846 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1850 tree orig_first_arg = first_arg;
1853 struct rejection_reason *reason = NULL;
1855 /* At this point we should not see any functions which haven't been
1856 explicitly declared, except for friend functions which will have
1857 been found using argument dependent lookup. */
1858 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1860 /* The `this', `in_chrg' and VTT arguments to constructors are not
1861 considered in overload resolution. */
1862 if (DECL_CONSTRUCTOR_P (fn))
1864 parmlist = skip_artificial_parms_for (fn, parmlist);
1865 skip = num_artificial_parms_for (fn);
1866 if (skip > 0 && first_arg != NULL_TREE)
1869 first_arg = NULL_TREE;
1875 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0);
1876 convs = alloc_conversions (len);
1878 /* 13.3.2 - Viable functions [over.match.viable]
1879 First, to be a viable function, a candidate function shall have enough
1880 parameters to agree in number with the arguments in the list.
1882 We need to check this first; otherwise, checking the ICSes might cause
1883 us to produce an ill-formed template instantiation. */
1885 parmnode = parmlist;
1886 for (i = 0; i < len; ++i)
1888 if (parmnode == NULL_TREE || parmnode == void_list_node)
1890 parmnode = TREE_CHAIN (parmnode);
1893 if ((i < len && parmnode)
1894 || !sufficient_parms_p (parmnode))
1896 int remaining = remaining_arguments (parmnode);
1898 reason = arity_rejection (first_arg, i + remaining, len);
1900 /* When looking for a function from a subobject from an implicit
1901 copy/move constructor/operator=, don't consider anything that takes (a
1902 reference to) an unrelated type. See c++/44909 and core 1092. */
1903 else if (parmlist && (flags & LOOKUP_DEFAULTED))
1905 if (DECL_CONSTRUCTOR_P (fn))
1907 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
1908 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
1914 parmnode = chain_index (i-1, parmlist);
1915 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
1920 /* This only applies at the top level. */
1921 flags &= ~LOOKUP_DEFAULTED;
1927 /* Second, for F to be a viable function, there shall exist for each
1928 argument an implicit conversion sequence that converts that argument
1929 to the corresponding parameter of F. */
1931 parmnode = parmlist;
1933 for (i = 0; i < len; ++i)
1935 tree arg, argtype, to_type;
1939 if (parmnode == void_list_node)
1942 if (i == 0 && first_arg != NULL_TREE)
1945 arg = VEC_index (tree, args,
1946 i + skip - (first_arg != NULL_TREE ? 1 : 0));
1947 argtype = lvalue_type (arg);
1949 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1950 && ! DECL_CONSTRUCTOR_P (fn));
1954 tree parmtype = TREE_VALUE (parmnode);
1957 parmnode = TREE_CHAIN (parmnode);
1959 /* The type of the implicit object parameter ('this') for
1960 overload resolution is not always the same as for the
1961 function itself; conversion functions are considered to
1962 be members of the class being converted, and functions
1963 introduced by a using-declaration are considered to be
1964 members of the class that uses them.
1966 Since build_over_call ignores the ICS for the `this'
1967 parameter, we can just change the parm type. */
1968 if (ctype && is_this)
1970 parmtype = cp_build_qualified_type
1971 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
1972 parmtype = build_pointer_type (parmtype);
1975 /* Core issue 899: When [copy-]initializing a temporary to be bound
1976 to the first parameter of a copy constructor (12.8) called with
1977 a single argument in the context of direct-initialization,
1978 explicit conversion functions are also considered.
1980 So set LOOKUP_COPY_PARM to let reference_binding know that
1981 it's being called in that context. We generalize the above
1982 to handle move constructors and template constructors as well;
1983 the standardese should soon be updated similarly. */
1984 if (ctype && i == 0 && (len-skip == 1)
1985 && !(flags & LOOKUP_ONLYCONVERTING)
1986 && DECL_CONSTRUCTOR_P (fn)
1987 && parmtype != error_mark_node
1988 && (same_type_ignoring_top_level_qualifiers_p
1989 (non_reference (parmtype), ctype)))
1991 lflags |= LOOKUP_COPY_PARM;
1992 /* We allow user-defined conversions within init-lists, but
1993 not for the copy constructor. */
1994 if (flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1995 lflags |= LOOKUP_NO_CONVERSION;
1998 lflags |= LOOKUP_ONLYCONVERTING;
2000 t = implicit_conversion (parmtype, argtype, arg,
2001 /*c_cast_p=*/false, lflags);
2006 t = build_identity_conv (argtype, arg);
2007 t->ellipsis_p = true;
2018 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
2025 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type);
2030 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
2031 access_path, conversion_path, viable, reason);
2034 /* Create an overload candidate for the conversion function FN which will
2035 be invoked for expression OBJ, producing a pointer-to-function which
2036 will in turn be called with the argument list FIRST_ARG/ARGLIST,
2037 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
2038 passed on to implicit_conversion.
2040 Actually, we don't really care about FN; we care about the type it
2041 converts to. There may be multiple conversion functions that will
2042 convert to that type, and we rely on build_user_type_conversion_1 to
2043 choose the best one; so when we create our candidate, we record the type
2044 instead of the function. */
2046 static struct z_candidate *
2047 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
2048 tree first_arg, const VEC(tree,gc) *arglist,
2049 tree access_path, tree conversion_path)
2051 tree totype = TREE_TYPE (TREE_TYPE (fn));
2052 int i, len, viable, flags;
2053 tree parmlist, parmnode;
2055 struct rejection_reason *reason;
2057 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
2058 parmlist = TREE_TYPE (parmlist);
2059 parmlist = TYPE_ARG_TYPES (parmlist);
2061 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1;
2062 convs = alloc_conversions (len);
2063 parmnode = parmlist;
2065 flags = LOOKUP_IMPLICIT;
2068 /* Don't bother looking up the same type twice. */
2069 if (*candidates && (*candidates)->fn == totype)
2072 for (i = 0; i < len; ++i)
2074 tree arg, argtype, convert_type = NULL_TREE;
2079 else if (i == 1 && first_arg != NULL_TREE)
2082 arg = VEC_index (tree, arglist,
2083 i - (first_arg != NULL_TREE ? 1 : 0) - 1);
2084 argtype = lvalue_type (arg);
2088 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
2090 convert_type = totype;
2092 else if (parmnode == void_list_node)
2096 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2097 /*c_cast_p=*/false, flags);
2098 convert_type = TREE_VALUE (parmnode);
2102 t = build_identity_conv (argtype, arg);
2103 t->ellipsis_p = true;
2104 convert_type = argtype;
2114 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type);
2121 parmnode = TREE_CHAIN (parmnode);
2125 || ! sufficient_parms_p (parmnode))
2127 int remaining = remaining_arguments (parmnode);
2129 reason = arity_rejection (NULL_TREE, i + remaining, len);
2132 return add_candidate (candidates, totype, first_arg, arglist, len, convs,
2133 access_path, conversion_path, viable, reason);
2137 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2138 tree type1, tree type2, tree *args, tree *argtypes,
2146 struct rejection_reason *reason = NULL;
2151 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2152 convs = alloc_conversions (num_convs);
2154 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2155 conversion ops are allowed. We handle that here by just checking for
2156 boolean_type_node because other operators don't ask for it. COND_EXPR
2157 also does contextual conversion to bool for the first operand, but we
2158 handle that in build_conditional_expr, and type1 here is operand 2. */
2159 if (type1 != boolean_type_node)
2160 flags |= LOOKUP_ONLYCONVERTING;
2162 for (i = 0; i < 2; ++i)
2167 t = implicit_conversion (types[i], argtypes[i], args[i],
2168 /*c_cast_p=*/false, flags);
2172 /* We need something for printing the candidate. */
2173 t = build_identity_conv (types[i], NULL_TREE);
2174 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2179 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2184 /* For COND_EXPR we rearranged the arguments; undo that now. */
2187 convs[2] = convs[1];
2188 convs[1] = convs[0];
2189 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2190 /*c_cast_p=*/false, flags);
2196 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2201 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2203 /*access_path=*/NULL_TREE,
2204 /*conversion_path=*/NULL_TREE,
2209 is_complete (tree t)
2211 return COMPLETE_TYPE_P (complete_type (t));
2214 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2217 promoted_arithmetic_type_p (tree type)
2221 In this section, the term promoted integral type is used to refer
2222 to those integral types which are preserved by integral promotion
2223 (including e.g. int and long but excluding e.g. char).
2224 Similarly, the term promoted arithmetic type refers to promoted
2225 integral types plus floating types. */
2226 return ((CP_INTEGRAL_TYPE_P (type)
2227 && same_type_p (type_promotes_to (type), type))
2228 || TREE_CODE (type) == REAL_TYPE);
2231 /* Create any builtin operator overload candidates for the operator in
2232 question given the converted operand types TYPE1 and TYPE2. The other
2233 args are passed through from add_builtin_candidates to
2234 build_builtin_candidate.
2236 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2237 If CODE is requires candidates operands of the same type of the kind
2238 of which TYPE1 and TYPE2 are, we add both candidates
2239 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2242 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2243 enum tree_code code2, tree fnname, tree type1,
2244 tree type2, tree *args, tree *argtypes, int flags)
2248 case POSTINCREMENT_EXPR:
2249 case POSTDECREMENT_EXPR:
2250 args[1] = integer_zero_node;
2251 type2 = integer_type_node;
2260 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2261 and VQ is either volatile or empty, there exist candidate operator
2262 functions of the form
2263 VQ T& operator++(VQ T&);
2264 T operator++(VQ T&, int);
2265 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2266 type other than bool, and VQ is either volatile or empty, there exist
2267 candidate operator functions of the form
2268 VQ T& operator--(VQ T&);
2269 T operator--(VQ T&, int);
2270 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2271 complete object type, and VQ is either volatile or empty, there exist
2272 candidate operator functions of the form
2273 T*VQ& operator++(T*VQ&);
2274 T*VQ& operator--(T*VQ&);
2275 T* operator++(T*VQ&, int);
2276 T* operator--(T*VQ&, int); */
2278 case POSTDECREMENT_EXPR:
2279 case PREDECREMENT_EXPR:
2280 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2282 case POSTINCREMENT_EXPR:
2283 case PREINCREMENT_EXPR:
2284 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2286 type1 = build_reference_type (type1);
2291 /* 7 For every cv-qualified or cv-unqualified object type T, there
2292 exist candidate operator functions of the form
2296 8 For every function type T, there exist candidate operator functions of
2298 T& operator*(T*); */
2301 if (TREE_CODE (type1) == POINTER_TYPE
2302 && !uses_template_parms (TREE_TYPE (type1))
2303 && (TYPE_PTROB_P (type1)
2304 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2308 /* 9 For every type T, there exist candidate operator functions of the form
2311 10For every promoted arithmetic type T, there exist candidate operator
2312 functions of the form
2316 case UNARY_PLUS_EXPR: /* unary + */
2317 if (TREE_CODE (type1) == POINTER_TYPE)
2320 if (ARITHMETIC_TYPE_P (type1))
2324 /* 11For every promoted integral type T, there exist candidate operator
2325 functions of the form
2329 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2333 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2334 is the same type as C2 or is a derived class of C2, T is a complete
2335 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2336 there exist candidate operator functions of the form
2337 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2338 where CV12 is the union of CV1 and CV2. */
2341 if (TREE_CODE (type1) == POINTER_TYPE
2342 && TYPE_PTR_TO_MEMBER_P (type2))
2344 tree c1 = TREE_TYPE (type1);
2345 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2347 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2348 && (TYPE_PTRMEMFUNC_P (type2)
2349 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2354 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2355 didate operator functions of the form
2360 bool operator<(L, R);
2361 bool operator>(L, R);
2362 bool operator<=(L, R);
2363 bool operator>=(L, R);
2364 bool operator==(L, R);
2365 bool operator!=(L, R);
2366 where LR is the result of the usual arithmetic conversions between
2369 14For every pair of types T and I, where T is a cv-qualified or cv-
2370 unqualified complete object type and I is a promoted integral type,
2371 there exist candidate operator functions of the form
2372 T* operator+(T*, I);
2373 T& operator[](T*, I);
2374 T* operator-(T*, I);
2375 T* operator+(I, T*);
2376 T& operator[](I, T*);
2378 15For every T, where T is a pointer to complete object type, there exist
2379 candidate operator functions of the form112)
2380 ptrdiff_t operator-(T, T);
2382 16For every pointer or enumeration type T, there exist candidate operator
2383 functions of the form
2384 bool operator<(T, T);
2385 bool operator>(T, T);
2386 bool operator<=(T, T);
2387 bool operator>=(T, T);
2388 bool operator==(T, T);
2389 bool operator!=(T, T);
2391 17For every pointer to member type T, there exist candidate operator
2392 functions of the form
2393 bool operator==(T, T);
2394 bool operator!=(T, T); */
2397 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2399 if (TYPE_PTROB_P (type1)
2400 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2402 type2 = ptrdiff_type_node;
2406 case TRUNC_DIV_EXPR:
2407 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2413 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2414 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
2416 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
2421 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
2433 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2435 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2437 if (TREE_CODE (type1) == ENUMERAL_TYPE
2438 && TREE_CODE (type2) == ENUMERAL_TYPE)
2440 if (TYPE_PTR_P (type1)
2441 && null_ptr_cst_p (args[1])
2442 && !uses_template_parms (type1))
2447 if (null_ptr_cst_p (args[0])
2448 && TYPE_PTR_P (type2)
2449 && !uses_template_parms (type2))
2457 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2460 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2462 type1 = ptrdiff_type_node;
2465 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2467 type2 = ptrdiff_type_node;
2472 /* 18For every pair of promoted integral types L and R, there exist candi-
2473 date operator functions of the form
2480 where LR is the result of the usual arithmetic conversions between
2483 case TRUNC_MOD_EXPR:
2489 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2493 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2494 type, VQ is either volatile or empty, and R is a promoted arithmetic
2495 type, there exist candidate operator functions of the form
2496 VQ L& operator=(VQ L&, R);
2497 VQ L& operator*=(VQ L&, R);
2498 VQ L& operator/=(VQ L&, R);
2499 VQ L& operator+=(VQ L&, R);
2500 VQ L& operator-=(VQ L&, R);
2502 20For every pair T, VQ), where T is any type and VQ is either volatile
2503 or empty, there exist candidate operator functions of the form
2504 T*VQ& operator=(T*VQ&, T*);
2506 21For every pair T, VQ), where T is a pointer to member type and VQ is
2507 either volatile or empty, there exist candidate operator functions of
2509 VQ T& operator=(VQ T&, T);
2511 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2512 unqualified complete object type, VQ is either volatile or empty, and
2513 I is a promoted integral type, there exist candidate operator func-
2515 T*VQ& operator+=(T*VQ&, I);
2516 T*VQ& operator-=(T*VQ&, I);
2518 23For every triple L, VQ, R), where L is an integral or enumeration
2519 type, VQ is either volatile or empty, and R is a promoted integral
2520 type, there exist candidate operator functions of the form
2522 VQ L& operator%=(VQ L&, R);
2523 VQ L& operator<<=(VQ L&, R);
2524 VQ L& operator>>=(VQ L&, R);
2525 VQ L& operator&=(VQ L&, R);
2526 VQ L& operator^=(VQ L&, R);
2527 VQ L& operator|=(VQ L&, R); */
2534 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2536 type2 = ptrdiff_type_node;
2540 case TRUNC_DIV_EXPR:
2541 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2545 case TRUNC_MOD_EXPR:
2551 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2556 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2558 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2559 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2560 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2561 || ((TYPE_PTRMEMFUNC_P (type1)
2562 || TREE_CODE (type1) == POINTER_TYPE)
2563 && null_ptr_cst_p (args[1])))
2573 type1 = build_reference_type (type1);
2579 For every pair of promoted arithmetic types L and R, there
2580 exist candidate operator functions of the form
2582 LR operator?(bool, L, R);
2584 where LR is the result of the usual arithmetic conversions
2585 between types L and R.
2587 For every type T, where T is a pointer or pointer-to-member
2588 type, there exist candidate operator functions of the form T
2589 operator?(bool, T, T); */
2591 if (promoted_arithmetic_type_p (type1)
2592 && promoted_arithmetic_type_p (type2))
2596 /* Otherwise, the types should be pointers. */
2597 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2598 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2601 /* We don't check that the two types are the same; the logic
2602 below will actually create two candidates; one in which both
2603 parameter types are TYPE1, and one in which both parameter
2609 if (ARITHMETIC_TYPE_P (type1))
2617 /* If we're dealing with two pointer types or two enumeral types,
2618 we need candidates for both of them. */
2619 if (type2 && !same_type_p (type1, type2)
2620 && TREE_CODE (type1) == TREE_CODE (type2)
2621 && (TREE_CODE (type1) == REFERENCE_TYPE
2622 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2623 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2624 || TYPE_PTRMEMFUNC_P (type1)
2625 || MAYBE_CLASS_TYPE_P (type1)
2626 || TREE_CODE (type1) == ENUMERAL_TYPE))
2628 build_builtin_candidate
2629 (candidates, fnname, type1, type1, args, argtypes, flags);
2630 build_builtin_candidate
2631 (candidates, fnname, type2, type2, args, argtypes, flags);
2635 build_builtin_candidate
2636 (candidates, fnname, type1, type2, args, argtypes, flags);
2640 type_decays_to (tree type)
2642 if (TREE_CODE (type) == ARRAY_TYPE)
2643 return build_pointer_type (TREE_TYPE (type));
2644 if (TREE_CODE (type) == FUNCTION_TYPE)
2645 return build_pointer_type (type);
2649 /* There are three conditions of builtin candidates:
2651 1) bool-taking candidates. These are the same regardless of the input.
2652 2) pointer-pair taking candidates. These are generated for each type
2653 one of the input types converts to.
2654 3) arithmetic candidates. According to the standard, we should generate
2655 all of these, but I'm trying not to...
2657 Here we generate a superset of the possible candidates for this particular
2658 case. That is a subset of the full set the standard defines, plus some
2659 other cases which the standard disallows. add_builtin_candidate will
2660 filter out the invalid set. */
2663 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2664 enum tree_code code2, tree fnname, tree *args,
2669 tree type, argtypes[3], t;
2670 /* TYPES[i] is the set of possible builtin-operator parameter types
2671 we will consider for the Ith argument. */
2672 VEC(tree,gc) *types[2];
2675 for (i = 0; i < 3; ++i)
2678 argtypes[i] = unlowered_expr_type (args[i]);
2680 argtypes[i] = NULL_TREE;
2685 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2686 and VQ is either volatile or empty, there exist candidate operator
2687 functions of the form
2688 VQ T& operator++(VQ T&); */
2690 case POSTINCREMENT_EXPR:
2691 case PREINCREMENT_EXPR:
2692 case POSTDECREMENT_EXPR:
2693 case PREDECREMENT_EXPR:
2698 /* 24There also exist candidate operator functions of the form
2699 bool operator!(bool);
2700 bool operator&&(bool, bool);
2701 bool operator||(bool, bool); */
2703 case TRUTH_NOT_EXPR:
2704 build_builtin_candidate
2705 (candidates, fnname, boolean_type_node,
2706 NULL_TREE, args, argtypes, flags);
2709 case TRUTH_ORIF_EXPR:
2710 case TRUTH_ANDIF_EXPR:
2711 build_builtin_candidate
2712 (candidates, fnname, boolean_type_node,
2713 boolean_type_node, args, argtypes, flags);
2735 types[0] = make_tree_vector ();
2736 types[1] = make_tree_vector ();
2738 for (i = 0; i < 2; ++i)
2742 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2746 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2749 convs = lookup_conversions (argtypes[i]);
2751 if (code == COND_EXPR)
2753 if (real_lvalue_p (args[i]))
2754 VEC_safe_push (tree, gc, types[i],
2755 build_reference_type (argtypes[i]));
2757 VEC_safe_push (tree, gc, types[i],
2758 TYPE_MAIN_VARIANT (argtypes[i]));
2764 for (; convs; convs = TREE_CHAIN (convs))
2766 type = TREE_TYPE (convs);
2769 && (TREE_CODE (type) != REFERENCE_TYPE
2770 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2773 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2774 VEC_safe_push (tree, gc, types[i], type);
2776 type = non_reference (type);
2777 if (i != 0 || ! ref1)
2779 type = cv_unqualified (type_decays_to (type));
2780 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2781 VEC_safe_push (tree, gc, types[i], type);
2782 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2783 type = type_promotes_to (type);
2786 if (! vec_member (type, types[i]))
2787 VEC_safe_push (tree, gc, types[i], type);
2792 if (code == COND_EXPR && real_lvalue_p (args[i]))
2793 VEC_safe_push (tree, gc, types[i],
2794 build_reference_type (argtypes[i]));
2795 type = non_reference (argtypes[i]);
2796 if (i != 0 || ! ref1)
2798 type = cv_unqualified (type_decays_to (type));
2799 if (enum_p && UNSCOPED_ENUM_P (type))
2800 VEC_safe_push (tree, gc, types[i], type);
2801 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2802 type = type_promotes_to (type);
2804 VEC_safe_push (tree, gc, types[i], type);
2808 /* Run through the possible parameter types of both arguments,
2809 creating candidates with those parameter types. */
2810 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t)
2815 if (!VEC_empty (tree, types[1]))
2816 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u)
2817 add_builtin_candidate
2818 (candidates, code, code2, fnname, t,
2819 u, args, argtypes, flags);
2821 add_builtin_candidate
2822 (candidates, code, code2, fnname, t,
2823 NULL_TREE, args, argtypes, flags);
2826 release_tree_vector (types[0]);
2827 release_tree_vector (types[1]);
2831 /* If TMPL can be successfully instantiated as indicated by
2832 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2834 TMPL is the template. EXPLICIT_TARGS are any explicit template
2835 arguments. ARGLIST is the arguments provided at the call-site.
2836 This does not change ARGLIST. The RETURN_TYPE is the desired type
2837 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2838 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2839 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2841 static struct z_candidate*
2842 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2843 tree ctype, tree explicit_targs, tree first_arg,
2844 const VEC(tree,gc) *arglist, tree return_type,
2845 tree access_path, tree conversion_path,
2846 int flags, tree obj, unification_kind_t strict)
2848 int ntparms = DECL_NTPARMS (tmpl);
2849 tree targs = make_tree_vec (ntparms);
2850 unsigned int len = VEC_length (tree, arglist);
2851 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
2852 unsigned int skip_without_in_chrg = 0;
2853 tree first_arg_without_in_chrg = first_arg;
2854 tree *args_without_in_chrg;
2855 unsigned int nargs_without_in_chrg;
2856 unsigned int ia, ix;
2858 struct z_candidate *cand;
2861 struct rejection_reason *reason = NULL;
2863 /* We don't do deduction on the in-charge parameter, the VTT
2864 parameter or 'this'. */
2865 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2867 if (first_arg_without_in_chrg != NULL_TREE)
2868 first_arg_without_in_chrg = NULL_TREE;
2870 ++skip_without_in_chrg;
2873 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2874 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2875 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2877 if (first_arg_without_in_chrg != NULL_TREE)
2878 first_arg_without_in_chrg = NULL_TREE;
2880 ++skip_without_in_chrg;
2883 if (len < skip_without_in_chrg)
2886 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
2887 + (len - skip_without_in_chrg));
2888 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
2890 if (first_arg_without_in_chrg != NULL_TREE)
2892 args_without_in_chrg[ia] = first_arg_without_in_chrg;
2895 for (ix = skip_without_in_chrg;
2896 VEC_iterate (tree, arglist, ix, arg);
2899 args_without_in_chrg[ia] = arg;
2902 gcc_assert (ia == nargs_without_in_chrg);
2904 i = fn_type_unification (tmpl, explicit_targs, targs,
2905 args_without_in_chrg,
2906 nargs_without_in_chrg,
2907 return_type, strict, flags);
2912 fn = instantiate_template (tmpl, targs, tf_none);
2913 if (fn == error_mark_node)
2918 A member function template is never instantiated to perform the
2919 copy of a class object to an object of its class type.
2921 It's a little unclear what this means; the standard explicitly
2922 does allow a template to be used to copy a class. For example,
2927 template <class T> A(const T&);
2930 void g () { A a (f ()); }
2932 the member template will be used to make the copy. The section
2933 quoted above appears in the paragraph that forbids constructors
2934 whose only parameter is (a possibly cv-qualified variant of) the
2935 class type, and a logical interpretation is that the intent was
2936 to forbid the instantiation of member templates which would then
2938 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
2940 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2941 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2946 if (obj != NULL_TREE)
2947 /* Aha, this is a conversion function. */
2948 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist,
2949 access_path, conversion_path);
2951 cand = add_function_candidate (candidates, fn, ctype,
2952 first_arg, arglist, access_path,
2953 conversion_path, flags);
2954 if (DECL_TI_TEMPLATE (fn) != tmpl)
2955 /* This situation can occur if a member template of a template
2956 class is specialized. Then, instantiate_template might return
2957 an instantiation of the specialization, in which case the
2958 DECL_TI_TEMPLATE field will point at the original
2959 specialization. For example:
2961 template <class T> struct S { template <class U> void f(U);
2962 template <> void f(int) {}; };
2966 Here, TMPL will be template <class U> S<double>::f(U).
2967 And, instantiate template will give us the specialization
2968 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2969 for this will point at template <class T> template <> S<T>::f(int),
2970 so that we can find the definition. For the purposes of
2971 overload resolution, however, we want the original TMPL. */
2972 cand->template_decl = build_template_info (tmpl, targs);
2974 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2975 cand->explicit_targs = explicit_targs;
2979 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
2980 access_path, conversion_path, 0, reason);
2984 static struct z_candidate *
2985 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2986 tree explicit_targs, tree first_arg,
2987 const VEC(tree,gc) *arglist, tree return_type,
2988 tree access_path, tree conversion_path, int flags,
2989 unification_kind_t strict)
2992 add_template_candidate_real (candidates, tmpl, ctype,
2993 explicit_targs, first_arg, arglist,
2994 return_type, access_path, conversion_path,
2995 flags, NULL_TREE, strict);
2999 static struct z_candidate *
3000 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
3001 tree obj, tree first_arg,
3002 const VEC(tree,gc) *arglist,
3003 tree return_type, tree access_path,
3004 tree conversion_path)
3007 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
3008 first_arg, arglist, return_type, access_path,
3009 conversion_path, 0, obj, DEDUCE_CONV);
3012 /* The CANDS are the set of candidates that were considered for
3013 overload resolution. Return the set of viable candidates, or CANDS
3014 if none are viable. If any of the candidates were viable, set
3015 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
3016 considered viable only if it is strictly viable. */
3018 static struct z_candidate*
3019 splice_viable (struct z_candidate *cands,
3023 struct z_candidate *viable;
3024 struct z_candidate **last_viable;
3025 struct z_candidate **cand;
3027 /* Be strict inside templates, since build_over_call won't actually
3028 do the conversions to get pedwarns. */
3029 if (processing_template_decl)
3033 last_viable = &viable;
3034 *any_viable_p = false;
3039 struct z_candidate *c = *cand;
3040 if (strict_p ? c->viable == 1 : c->viable)
3045 last_viable = &c->next;
3046 *any_viable_p = true;
3052 return viable ? viable : cands;
3056 any_strictly_viable (struct z_candidate *cands)
3058 for (; cands; cands = cands->next)
3059 if (cands->viable == 1)
3064 /* OBJ is being used in an expression like "OBJ.f (...)". In other
3065 words, it is about to become the "this" pointer for a member
3066 function call. Take the address of the object. */
3069 build_this (tree obj)
3071 /* In a template, we are only concerned about the type of the
3072 expression, so we can take a shortcut. */
3073 if (processing_template_decl)
3074 return build_address (obj);
3076 return cp_build_addr_expr (obj, tf_warning_or_error);
3079 /* Returns true iff functions are equivalent. Equivalent functions are
3080 not '==' only if one is a function-local extern function or if
3081 both are extern "C". */
3084 equal_functions (tree fn1, tree fn2)
3086 if (TREE_CODE (fn1) != TREE_CODE (fn2))
3088 if (TREE_CODE (fn1) == TEMPLATE_DECL)
3090 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
3091 || DECL_EXTERN_C_FUNCTION_P (fn1))
3092 return decls_match (fn1, fn2);
3096 /* Print information about a candidate being rejected due to INFO. */
3099 print_conversion_rejection (location_t loc, struct conversion_info *info)
3101 if (info->n_arg == -1)
3102 /* Conversion of implicit `this' argument failed. */
3103 inform (loc, " no known conversion for implicit "
3104 "%<this%> parameter from %qT to %qT",
3105 info->from_type, info->to_type);
3107 inform (loc, " no known conversion for argument %d from %qT to %qT",
3108 info->n_arg+1, info->from_type, info->to_type);
3111 /* Print information about one overload candidate CANDIDATE. MSGSTR
3112 is the text to print before the candidate itself.
3114 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3115 to have been run through gettext by the caller. This wart makes
3116 life simpler in print_z_candidates and for the translators. */
3119 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
3121 const char *msg = (msgstr == NULL
3123 : ACONCAT ((msgstr, " ", NULL)));
3124 location_t loc = location_of (candidate->fn);
3126 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
3128 if (candidate->num_convs == 3)
3129 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn,
3130 candidate->convs[0]->type,
3131 candidate->convs[1]->type,
3132 candidate->convs[2]->type);
3133 else if (candidate->num_convs == 2)
3134 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn,
3135 candidate->convs[0]->type,
3136 candidate->convs[1]->type);
3138 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn,
3139 candidate->convs[0]->type);
3141 else if (TYPE_P (candidate->fn))
3142 inform (input_location, "%s%T <conversion>", msg, candidate->fn);
3143 else if (candidate->viable == -1)
3144 inform (loc, "%s%#D <near match>", msg, candidate->fn);
3145 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn)))
3146 inform (loc, "%s%#D <deleted>", msg, candidate->fn);
3148 inform (loc, "%s%#D", msg, candidate->fn);
3149 /* Give the user some information about why this candidate failed. */
3150 if (candidate->reason != NULL)
3152 struct rejection_reason *r = candidate->reason;
3157 inform_n (loc, r->u.arity.expected,
3158 " candidate expects %d argument, %d provided",
3159 " candidate expects %d arguments, %d provided",
3160 r->u.arity.expected, r->u.arity.actual);
3162 case rr_arg_conversion:
3163 print_conversion_rejection (loc, &r->u.conversion);
3165 case rr_bad_arg_conversion:
3166 print_conversion_rejection (loc, &r->u.bad_conversion);
3168 case rr_explicit_conversion:
3169 inform (loc, " return type %qT of explicit conversion function "
3170 "cannot be converted to %qT with a qualification "
3171 "conversion", r->u.conversion.from_type,
3172 r->u.conversion.to_type);
3176 /* This candidate didn't have any issues or we failed to
3177 handle a particular code. Either way... */
3184 print_z_candidates (location_t loc, struct z_candidate *candidates)
3186 struct z_candidate *cand1;
3187 struct z_candidate **cand2;
3193 /* Remove non-viable deleted candidates. */
3195 for (cand2 = &cand1; *cand2; )
3197 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3198 && !(*cand2)->viable
3199 && DECL_DELETED_FN ((*cand2)->fn))
3200 *cand2 = (*cand2)->next;
3202 cand2 = &(*cand2)->next;
3204 /* ...if there are any non-deleted ones. */
3208 /* There may be duplicates in the set of candidates. We put off
3209 checking this condition as long as possible, since we have no way
3210 to eliminate duplicates from a set of functions in less than n^2
3211 time. Now we are about to emit an error message, so it is more
3212 permissible to go slowly. */
3213 for (cand1 = candidates; cand1; cand1 = cand1->next)
3215 tree fn = cand1->fn;
3216 /* Skip builtin candidates and conversion functions. */
3219 cand2 = &cand1->next;
3222 if (DECL_P ((*cand2)->fn)
3223 && equal_functions (fn, (*cand2)->fn))
3224 *cand2 = (*cand2)->next;
3226 cand2 = &(*cand2)->next;
3230 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next)
3233 inform_n (loc, n_candidates, "candidate is:", "candidates are:");
3234 for (; candidates; candidates = candidates->next)
3235 print_z_candidate (NULL, candidates);
3238 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3239 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3240 the result of the conversion function to convert it to the final
3241 desired type. Merge the two sequences into a single sequence,
3242 and return the merged sequence. */
3245 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3249 gcc_assert (user_seq->kind == ck_user);
3251 /* Find the end of the second conversion sequence. */
3253 while ((*t)->kind != ck_identity)
3254 t = &((*t)->u.next);
3256 /* Replace the identity conversion with the user conversion
3260 /* The entire sequence is a user-conversion sequence. */
3261 std_seq->user_conv_p = true;
3266 /* Handle overload resolution for initializing an object of class type from
3267 an initializer list. First we look for a suitable constructor that
3268 takes a std::initializer_list; if we don't find one, we then look for a
3269 non-list constructor.
3271 Parameters are as for add_candidates, except that the arguments are in
3272 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and
3273 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3276 add_list_candidates (tree fns, tree first_arg,
3277 tree init_list, tree totype,
3278 tree explicit_targs, bool template_only,
3279 tree conversion_path, tree access_path,
3281 struct z_candidate **candidates)
3285 gcc_assert (*candidates == NULL);
3287 /* For list-initialization we consider explicit constructors, but
3288 give an error if one is selected. */
3289 flags &= ~LOOKUP_ONLYCONVERTING;
3290 /* And we don't allow narrowing conversions. We also use this flag to
3291 avoid the copy constructor call for copy-list-initialization. */
3292 flags |= LOOKUP_NO_NARROWING;
3294 /* Always use the default constructor if the list is empty (DR 990). */
3295 if (CONSTRUCTOR_NELTS (init_list) == 0
3296 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3298 /* If the class has a list ctor, try passing the list as a single
3299 argument first, but only consider list ctors. */
3300 else if (TYPE_HAS_LIST_CTOR (totype))
3302 flags |= LOOKUP_LIST_ONLY;
3303 args = make_tree_vector_single (init_list);
3304 add_candidates (fns, first_arg, args, NULL_TREE,
3305 explicit_targs, template_only, conversion_path,
3306 access_path, flags, candidates);
3307 if (any_strictly_viable (*candidates))
3311 args = ctor_to_vec (init_list);
3313 /* We aren't looking for list-ctors anymore. */
3314 flags &= ~LOOKUP_LIST_ONLY;
3315 /* We allow more user-defined conversions within an init-list. */
3316 flags &= ~LOOKUP_NO_CONVERSION;
3317 /* But not for the copy ctor. */
3318 flags |= LOOKUP_NO_COPY_CTOR_CONVERSION;
3320 add_candidates (fns, first_arg, args, NULL_TREE,
3321 explicit_targs, template_only, conversion_path,
3322 access_path, flags, candidates);
3325 /* Returns the best overload candidate to perform the requested
3326 conversion. This function is used for three the overloading situations
3327 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3328 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
3329 per [dcl.init.ref], so we ignore temporary bindings. */
3331 static struct z_candidate *
3332 build_user_type_conversion_1 (tree totype, tree expr, int flags)
3334 struct z_candidate *candidates, *cand;
3335 tree fromtype = TREE_TYPE (expr);
3336 tree ctors = NULL_TREE;
3337 tree conv_fns = NULL_TREE;
3338 conversion *conv = NULL;
3339 tree first_arg = NULL_TREE;
3340 VEC(tree,gc) *args = NULL;
3344 /* We represent conversion within a hierarchy using RVALUE_CONV and
3345 BASE_CONV, as specified by [over.best.ics]; these become plain
3346 constructor calls, as specified in [dcl.init]. */
3347 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3348 || !DERIVED_FROM_P (totype, fromtype));
3350 if (MAYBE_CLASS_TYPE_P (totype))
3351 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3352 creating a garbage BASELINK; constructors can't be inherited. */
3353 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier);
3355 if (MAYBE_CLASS_TYPE_P (fromtype))
3357 tree to_nonref = non_reference (totype);
3358 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3359 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3360 && DERIVED_FROM_P (to_nonref, fromtype)))
3362 /* [class.conv.fct] A conversion function is never used to
3363 convert a (possibly cv-qualified) object to the (possibly
3364 cv-qualified) same object type (or a reference to it), to a
3365 (possibly cv-qualified) base class of that type (or a
3366 reference to it)... */
3369 conv_fns = lookup_conversions (fromtype);
3373 flags |= LOOKUP_NO_CONVERSION;
3374 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3375 flags |= LOOKUP_NO_NARROWING;
3377 /* It's OK to bind a temporary for converting constructor arguments, but
3378 not in converting the return value of a conversion operator. */
3379 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
3380 flags &= ~LOOKUP_NO_TEMP_BIND;
3384 int ctorflags = flags;
3386 first_arg = build_int_cst (build_pointer_type (totype), 0);
3388 /* We should never try to call the abstract or base constructor
3390 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
3391 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
3393 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3395 /* List-initialization. */
3396 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE,
3397 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3398 ctorflags, &candidates);
3402 args = make_tree_vector_single (expr);
3403 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3404 TYPE_BINFO (totype), TYPE_BINFO (totype),
3405 ctorflags, &candidates);
3408 for (cand = candidates; cand; cand = cand->next)
3410 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3412 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3413 set, then this is copy-initialization. In that case, "The
3414 result of the call is then used to direct-initialize the
3415 object that is the destination of the copy-initialization."
3418 We represent this in the conversion sequence with an
3419 rvalue conversion, which means a constructor call. */
3420 if (TREE_CODE (totype) != REFERENCE_TYPE
3421 && !(convflags & LOOKUP_NO_TEMP_BIND))
3423 = build_conv (ck_rvalue, totype, cand->second_conv);
3428 first_arg = build_this (expr);
3430 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3432 tree conversion_path = TREE_PURPOSE (conv_fns);
3433 struct z_candidate *old_candidates;
3435 /* If we are called to convert to a reference type, we are trying to
3436 find an lvalue binding, so don't even consider temporaries. If
3437 we don't find an lvalue binding, the caller will try again to
3438 look for a temporary binding. */
3439 if (TREE_CODE (totype) == REFERENCE_TYPE)
3440 convflags |= LOOKUP_NO_TEMP_BIND;
3442 old_candidates = candidates;
3443 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3445 conversion_path, TYPE_BINFO (fromtype),
3446 flags, &candidates);
3448 for (cand = candidates; cand != old_candidates; cand = cand->next)
3450 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3452 = implicit_conversion (totype,
3455 /*c_cast_p=*/false, convflags);
3457 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3458 copy-initialization. In that case, "The result of the
3459 call is then used to direct-initialize the object that is
3460 the destination of the copy-initialization." [dcl.init]
3462 We represent this in the conversion sequence with an
3463 rvalue conversion, which means a constructor call. But
3464 don't add a second rvalue conversion if there's already
3465 one there. Which there really shouldn't be, but it's
3466 harmless since we'd add it here anyway. */
3467 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3468 && !(convflags & LOOKUP_NO_TEMP_BIND))
3469 ics = build_conv (ck_rvalue, totype, ics);
3471 cand->second_conv = ics;
3476 cand->reason = arg_conversion_rejection (NULL_TREE, -1,
3479 else if (DECL_NONCONVERTING_P (cand->fn)
3480 && ics->rank > cr_exact)
3482 /* 13.3.1.5: For direct-initialization, those explicit
3483 conversion functions that are not hidden within S and
3484 yield type T or a type that can be converted to type T
3485 with a qualification conversion (4.4) are also candidate
3488 cand->reason = explicit_conversion_rejection (rettype, totype);
3490 else if (cand->viable == 1 && ics->bad_p)
3494 = bad_arg_conversion_rejection (NULL_TREE, -1,
3500 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3504 release_tree_vector (args);
3508 cand = tourney (candidates);
3511 if (flags & LOOKUP_COMPLAIN)
3513 error ("conversion from %qT to %qT is ambiguous",
3515 print_z_candidates (location_of (expr), candidates);
3518 cand = candidates; /* any one will do */
3519 cand->second_conv = build_ambiguous_conv (totype, expr);
3520 cand->second_conv->user_conv_p = true;
3521 if (!any_strictly_viable (candidates))
3522 cand->second_conv->bad_p = true;
3523 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3524 ambiguous conversion is no worse than another user-defined
3530 /* Build the user conversion sequence. */
3533 (DECL_CONSTRUCTOR_P (cand->fn)
3534 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
3535 build_identity_conv (TREE_TYPE (expr), expr));
3538 /* Remember that this was a list-initialization. */
3539 if (flags & LOOKUP_NO_NARROWING)
3540 conv->check_narrowing = true;
3542 /* Combine it with the second conversion sequence. */
3543 cand->second_conv = merge_conversion_sequences (conv,
3546 if (cand->viable == -1)
3547 cand->second_conv->bad_p = true;
3552 /* Wrapper for above. */
3555 build_user_type_conversion (tree totype, tree expr, int flags)
3557 struct z_candidate *cand;
3560 bool subtime = timevar_cond_start (TV_OVERLOAD);
3561 cand = build_user_type_conversion_1 (totype, expr, flags);
3565 if (cand->second_conv->kind == ck_ambig)
3566 ret = error_mark_node;
3569 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
3570 ret = convert_from_reference (expr);
3576 timevar_cond_stop (TV_OVERLOAD, subtime);
3580 /* Subroutine of convert_nontype_argument.
3582 EXPR is an argument for a template non-type parameter of integral or
3583 enumeration type. Do any necessary conversions (that are permitted for
3584 non-type arguments) to convert it to the parameter type.
3586 If conversion is successful, returns the converted expression;
3587 otherwise, returns error_mark_node. */
3590 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain)
3596 if (error_operand_p (expr))
3597 return error_mark_node;
3599 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3601 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3602 p = conversion_obstack_alloc (0);
3604 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
3608 /* for a non-type template-parameter of integral or
3609 enumeration type, integral promotions (4.5) and integral
3610 conversions (4.7) are applied. */
3611 /* It should be sufficient to check the outermost conversion step, since
3612 there are no qualification conversions to integer type. */
3616 /* A conversion function is OK. If it isn't constexpr, we'll
3617 complain later that the argument isn't constant. */
3619 /* The lvalue-to-rvalue conversion is OK. */
3625 t = conv->u.next->type;
3626 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t))
3629 if (complain & tf_error)
3630 error ("conversion from %qT to %qT not considered for "
3631 "non-type template argument", t, type);
3632 /* and fall through. */
3640 expr = convert_like (conv, expr, complain);
3642 expr = error_mark_node;
3644 /* Free all the conversions we allocated. */
3645 obstack_free (&conversion_obstack, p);
3650 /* Do any initial processing on the arguments to a function call. */
3652 static VEC(tree,gc) *
3653 resolve_args (VEC(tree,gc) *args, tsubst_flags_t complain)
3658 FOR_EACH_VEC_ELT (tree, args, ix, arg)
3660 if (error_operand_p (arg))
3662 else if (VOID_TYPE_P (TREE_TYPE (arg)))
3664 if (complain & tf_error)
3665 error ("invalid use of void expression");
3668 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
3674 /* Perform overload resolution on FN, which is called with the ARGS.
3676 Return the candidate function selected by overload resolution, or
3677 NULL if the event that overload resolution failed. In the case
3678 that overload resolution fails, *CANDIDATES will be the set of
3679 candidates considered, and ANY_VIABLE_P will be set to true or
3680 false to indicate whether or not any of the candidates were
3683 The ARGS should already have gone through RESOLVE_ARGS before this
3684 function is called. */
3686 static struct z_candidate *
3687 perform_overload_resolution (tree fn,
3688 const VEC(tree,gc) *args,
3689 struct z_candidate **candidates,
3692 struct z_candidate *cand;
3693 tree explicit_targs;
3696 bool subtime = timevar_cond_start (TV_OVERLOAD);
3698 explicit_targs = NULL_TREE;
3702 *any_viable_p = true;
3705 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
3706 || TREE_CODE (fn) == TEMPLATE_DECL
3707 || TREE_CODE (fn) == OVERLOAD
3708 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3710 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3712 explicit_targs = TREE_OPERAND (fn, 1);
3713 fn = TREE_OPERAND (fn, 0);
3717 /* Add the various candidate functions. */
3718 add_candidates (fn, NULL_TREE, args, NULL_TREE,
3719 explicit_targs, template_only,
3720 /*conversion_path=*/NULL_TREE,
3721 /*access_path=*/NULL_TREE,
3725 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3727 cand = tourney (*candidates);
3731 timevar_cond_stop (TV_OVERLOAD, subtime);
3735 /* Print an error message about being unable to build a call to FN with
3736 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
3737 be located; CANDIDATES is a possibly empty list of such
3741 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p,
3742 struct z_candidate *candidates)
3744 tree name = DECL_NAME (OVL_CURRENT (fn));
3745 location_t loc = location_of (name);
3748 error_at (loc, "no matching function for call to %<%D(%A)%>",
3749 name, build_tree_list_vec (args));
3751 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
3752 name, build_tree_list_vec (args));
3754 print_z_candidates (loc, candidates);
3757 /* Return an expression for a call to FN (a namespace-scope function,
3758 or a static member function) with the ARGS. This may change
3762 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p,
3763 tsubst_flags_t complain)
3765 struct z_candidate *candidates, *cand;
3770 if (args != NULL && *args != NULL)
3772 *args = resolve_args (*args, complain);
3774 return error_mark_node;
3777 /* If this function was found without using argument dependent
3778 lookup, then we want to ignore any undeclared friend
3784 fn = remove_hidden_names (fn);
3787 if (complain & tf_error)
3788 print_error_for_call_failure (orig_fn, *args, false, NULL);
3789 return error_mark_node;
3793 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3794 p = conversion_obstack_alloc (0);
3796 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p);
3800 if (complain & tf_error)
3802 if (!any_viable_p && candidates && ! candidates->next
3803 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
3804 return cp_build_function_call_vec (candidates->fn, args, complain);
3805 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3806 fn = TREE_OPERAND (fn, 0);
3807 print_error_for_call_failure (fn, *args, any_viable_p, candidates);
3809 result = error_mark_node;
3813 int flags = LOOKUP_NORMAL;
3814 /* If fn is template_id_expr, the call has explicit template arguments
3815 (e.g. func<int>(5)), communicate this info to build_over_call
3816 through flags so that later we can use it to decide whether to warn
3817 about peculiar null pointer conversion. */
3818 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3819 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
3820 result = build_over_call (cand, flags, complain);
3823 /* Free all the conversions we allocated. */
3824 obstack_free (&conversion_obstack, p);
3829 /* Build a call to a global operator new. FNNAME is the name of the
3830 operator (either "operator new" or "operator new[]") and ARGS are
3831 the arguments provided. This may change ARGS. *SIZE points to the
3832 total number of bytes required by the allocation, and is updated if
3833 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3834 be used. If this function determines that no cookie should be
3835 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3836 non-NULL, it will be set, upon return, to the allocation function
3840 build_operator_new_call (tree fnname, VEC(tree,gc) **args,
3841 tree *size, tree *cookie_size,
3845 struct z_candidate *candidates;
3846 struct z_candidate *cand;
3851 VEC_safe_insert (tree, gc, *args, 0, *size);
3852 *args = resolve_args (*args, tf_warning_or_error);
3854 return error_mark_node;
3860 If this lookup fails to find the name, or if the allocated type
3861 is not a class type, the allocation function's name is looked
3862 up in the global scope.
3864 we disregard block-scope declarations of "operator new". */
3865 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
3867 /* Figure out what function is being called. */
3868 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p);
3870 /* If no suitable function could be found, issue an error message
3874 print_error_for_call_failure (fns, *args, any_viable_p, candidates);
3875 return error_mark_node;
3878 /* If a cookie is required, add some extra space. Whether
3879 or not a cookie is required cannot be determined until
3880 after we know which function was called. */
3883 bool use_cookie = true;
3884 if (!abi_version_at_least (2))
3886 /* In G++ 3.2, the check was implemented incorrectly; it
3887 looked at the placement expression, rather than the
3888 type of the function. */
3889 if (VEC_length (tree, *args) == 2
3890 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)),
3898 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3899 /* Skip the size_t parameter. */
3900 arg_types = TREE_CHAIN (arg_types);
3901 /* Check the remaining parameters (if any). */
3903 && TREE_CHAIN (arg_types) == void_list_node
3904 && same_type_p (TREE_VALUE (arg_types),
3908 /* If we need a cookie, adjust the number of bytes allocated. */
3911 /* Update the total size. */
3912 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3913 /* Update the argument list to reflect the adjusted size. */
3914 VEC_replace (tree, *args, 0, *size);
3917 *cookie_size = NULL_TREE;
3920 /* Tell our caller which function we decided to call. */
3924 /* Build the CALL_EXPR. */
3925 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3928 /* Build a new call to operator(). This may change ARGS. */
3931 build_op_call_1 (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain)
3933 struct z_candidate *candidates = 0, *cand;
3934 tree fns, convs, first_mem_arg = NULL_TREE;
3935 tree type = TREE_TYPE (obj);
3937 tree result = NULL_TREE;
3940 if (error_operand_p (obj))
3941 return error_mark_node;
3943 obj = prep_operand (obj);
3945 if (TYPE_PTRMEMFUNC_P (type))
3947 if (complain & tf_error)
3948 /* It's no good looking for an overloaded operator() on a
3949 pointer-to-member-function. */
3950 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3951 return error_mark_node;
3954 if (TYPE_BINFO (type))
3956 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3957 if (fns == error_mark_node)
3958 return error_mark_node;
3963 if (args != NULL && *args != NULL)
3965 *args = resolve_args (*args, complain);
3967 return error_mark_node;
3970 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3971 p = conversion_obstack_alloc (0);
3975 first_mem_arg = build_this (obj);
3977 add_candidates (BASELINK_FUNCTIONS (fns),
3978 first_mem_arg, *args, NULL_TREE,
3980 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
3981 LOOKUP_NORMAL, &candidates);
3984 convs = lookup_conversions (type);
3986 for (; convs; convs = TREE_CHAIN (convs))
3988 tree fns = TREE_VALUE (convs);
3989 tree totype = TREE_TYPE (convs);
3991 if ((TREE_CODE (totype) == POINTER_TYPE
3992 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3993 || (TREE_CODE (totype) == REFERENCE_TYPE
3994 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3995 || (TREE_CODE (totype) == REFERENCE_TYPE
3996 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3997 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3998 for (; fns; fns = OVL_NEXT (fns))
4000 tree fn = OVL_CURRENT (fns);
4002 if (DECL_NONCONVERTING_P (fn))
4005 if (TREE_CODE (fn) == TEMPLATE_DECL)
4006 add_template_conv_candidate
4007 (&candidates, fn, obj, NULL_TREE, *args, totype,
4008 /*access_path=*/NULL_TREE,
4009 /*conversion_path=*/NULL_TREE);
4011 add_conv_candidate (&candidates, fn, obj, NULL_TREE,
4012 *args, /*conversion_path=*/NULL_TREE,
4013 /*access_path=*/NULL_TREE);
4017 candidates = splice_viable (candidates, pedantic, &any_viable_p);
4020 if (complain & tf_error)
4022 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
4023 build_tree_list_vec (*args));
4024 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4026 result = error_mark_node;
4030 cand = tourney (candidates);
4033 if (complain & tf_error)
4035 error ("call of %<(%T) (%A)%> is ambiguous",
4036 TREE_TYPE (obj), build_tree_list_vec (*args));
4037 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
4039 result = error_mark_node;
4041 /* Since cand->fn will be a type, not a function, for a conversion
4042 function, we must be careful not to unconditionally look at
4044 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
4045 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
4046 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4049 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
4051 obj = convert_from_reference (obj);
4052 result = cp_build_function_call_vec (obj, args, complain);
4056 /* Free all the conversions we allocated. */
4057 obstack_free (&conversion_obstack, p);
4062 /* Wrapper for above. */
4065 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain)
4068 bool subtime = timevar_cond_start (TV_OVERLOAD);
4069 ret = build_op_call_1 (obj, args, complain);
4070 timevar_cond_stop (TV_OVERLOAD, subtime);
4075 op_error (enum tree_code code, enum tree_code code2,
4076 tree arg1, tree arg2, tree arg3, bool match)
4080 if (code == MODIFY_EXPR)
4081 opname = assignment_operator_name_info[code2].name;
4083 opname = operator_name_info[code].name;
4089 error ("ambiguous overload for ternary %<operator?:%> "
4090 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
4092 error ("no match for ternary %<operator?:%> "
4093 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
4096 case POSTINCREMENT_EXPR:
4097 case POSTDECREMENT_EXPR:
4099 error ("ambiguous overload for %<operator%s%> in %<%E%s%>",
4100 opname, arg1, opname);
4102 error ("no match for %<operator%s%> in %<%E%s%>",
4103 opname, arg1, opname);
4108 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>",
4111 error ("no match for %<operator[]%> in %<%E[%E]%>",
4118 error ("ambiguous overload for %qs in %<%s %E%>",
4119 opname, opname, arg1);
4121 error ("no match for %qs in %<%s %E%>",
4122 opname, opname, arg1);
4128 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>",
4129 opname, arg1, opname, arg2);
4131 error ("no match for %<operator%s%> in %<%E %s %E%>",
4132 opname, arg1, opname, arg2);
4135 error ("ambiguous overload for %<operator%s%> in %<%s%E%>",
4136 opname, opname, arg1);
4138 error ("no match for %<operator%s%> in %<%s%E%>",
4139 opname, opname, arg1);
4144 /* Return the implicit conversion sequence that could be used to
4145 convert E1 to E2 in [expr.cond]. */
4148 conditional_conversion (tree e1, tree e2)
4150 tree t1 = non_reference (TREE_TYPE (e1));
4151 tree t2 = non_reference (TREE_TYPE (e2));
4157 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4158 implicitly converted (clause _conv_) to the type "reference to
4159 T2", subject to the constraint that in the conversion the
4160 reference must bind directly (_dcl.init.ref_) to E1. */
4161 if (real_lvalue_p (e2))
4163 conv = implicit_conversion (build_reference_type (t2),
4167 LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING);
4174 If E1 and E2 have class type, and the underlying class types are
4175 the same or one is a base class of the other: E1 can be converted
4176 to match E2 if the class of T2 is the same type as, or a base
4177 class of, the class of T1, and the cv-qualification of T2 is the
4178 same cv-qualification as, or a greater cv-qualification than, the
4179 cv-qualification of T1. If the conversion is applied, E1 is
4180 changed to an rvalue of type T2 that still refers to the original
4181 source class object (or the appropriate subobject thereof). */
4182 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4183 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4185 if (good_base && at_least_as_qualified_p (t2, t1))
4187 conv = build_identity_conv (t1, e1);
4188 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4189 TYPE_MAIN_VARIANT (t2)))
4190 conv = build_conv (ck_base, t2, conv);
4192 conv = build_conv (ck_rvalue, t2, conv);
4201 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4202 converted to the type that expression E2 would have if E2 were
4203 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4204 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4208 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4209 arguments to the conditional expression. */
4212 build_conditional_expr_1 (tree arg1, tree arg2, tree arg3,
4213 tsubst_flags_t complain)
4217 tree result = NULL_TREE;
4218 tree result_type = NULL_TREE;
4219 bool lvalue_p = true;
4220 struct z_candidate *candidates = 0;
4221 struct z_candidate *cand;
4224 /* As a G++ extension, the second argument to the conditional can be
4225 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4226 c'.) If the second operand is omitted, make sure it is
4227 calculated only once. */
4230 if (complain & tf_error)
4231 pedwarn (input_location, OPT_pedantic,
4232 "ISO C++ forbids omitting the middle term of a ?: expression");
4234 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4235 if (real_lvalue_p (arg1))
4236 arg2 = arg1 = stabilize_reference (arg1);
4238 arg2 = arg1 = save_expr (arg1);
4243 The first expression is implicitly converted to bool (clause
4245 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4248 /* If something has already gone wrong, just pass that fact up the
4250 if (error_operand_p (arg1)
4251 || error_operand_p (arg2)
4252 || error_operand_p (arg3))
4253 return error_mark_node;
4257 If either the second or the third operand has type (possibly
4258 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4259 array-to-pointer (_conv.array_), and function-to-pointer
4260 (_conv.func_) standard conversions are performed on the second
4261 and third operands. */
4262 arg2_type = unlowered_expr_type (arg2);
4263 arg3_type = unlowered_expr_type (arg3);
4264 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4266 /* Do the conversions. We don't these for `void' type arguments
4267 since it can't have any effect and since decay_conversion
4268 does not handle that case gracefully. */
4269 if (!VOID_TYPE_P (arg2_type))
4270 arg2 = decay_conversion (arg2);
4271 if (!VOID_TYPE_P (arg3_type))
4272 arg3 = decay_conversion (arg3);
4273 arg2_type = TREE_TYPE (arg2);
4274 arg3_type = TREE_TYPE (arg3);
4278 One of the following shall hold:
4280 --The second or the third operand (but not both) is a
4281 throw-expression (_except.throw_); the result is of the
4282 type of the other and is an rvalue.
4284 --Both the second and the third operands have type void; the
4285 result is of type void and is an rvalue.
4287 We must avoid calling force_rvalue for expressions of type
4288 "void" because it will complain that their value is being
4290 if (TREE_CODE (arg2) == THROW_EXPR
4291 && TREE_CODE (arg3) != THROW_EXPR)
4293 if (!VOID_TYPE_P (arg3_type))
4295 arg3 = force_rvalue (arg3, complain);
4296 if (arg3 == error_mark_node)
4297 return error_mark_node;
4299 arg3_type = TREE_TYPE (arg3);
4300 result_type = arg3_type;
4302 else if (TREE_CODE (arg2) != THROW_EXPR
4303 && TREE_CODE (arg3) == THROW_EXPR)
4305 if (!VOID_TYPE_P (arg2_type))
4307 arg2 = force_rvalue (arg2, complain);
4308 if (arg2 == error_mark_node)
4309 return error_mark_node;
4311 arg2_type = TREE_TYPE (arg2);
4312 result_type = arg2_type;
4314 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
4315 result_type = void_type_node;
4318 if (complain & tf_error)
4320 if (VOID_TYPE_P (arg2_type))
4321 error ("second operand to the conditional operator "
4322 "is of type %<void%>, "
4323 "but the third operand is neither a throw-expression "
4324 "nor of type %<void%>");
4326 error ("third operand to the conditional operator "
4327 "is of type %<void%>, "
4328 "but the second operand is neither a throw-expression "
4329 "nor of type %<void%>");
4331 return error_mark_node;
4335 goto valid_operands;
4339 Otherwise, if the second and third operand have different types,
4340 and either has (possibly cv-qualified) class type, an attempt is
4341 made to convert each of those operands to the type of the other. */
4342 else if (!same_type_p (arg2_type, arg3_type)
4343 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4348 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4349 p = conversion_obstack_alloc (0);
4351 conv2 = conditional_conversion (arg2, arg3);
4352 conv3 = conditional_conversion (arg3, arg2);
4356 If both can be converted, or one can be converted but the
4357 conversion is ambiguous, the program is ill-formed. If
4358 neither can be converted, the operands are left unchanged and
4359 further checking is performed as described below. If exactly
4360 one conversion is possible, that conversion is applied to the
4361 chosen operand and the converted operand is used in place of
4362 the original operand for the remainder of this section. */
4363 if ((conv2 && !conv2->bad_p
4364 && conv3 && !conv3->bad_p)
4365 || (conv2 && conv2->kind == ck_ambig)
4366 || (conv3 && conv3->kind == ck_ambig))
4368 error ("operands to ?: have different types %qT and %qT",
4369 arg2_type, arg3_type);
4370 result = error_mark_node;
4372 else if (conv2 && (!conv2->bad_p || !conv3))
4374 arg2 = convert_like (conv2, arg2, complain);
4375 arg2 = convert_from_reference (arg2);
4376 arg2_type = TREE_TYPE (arg2);
4377 /* Even if CONV2 is a valid conversion, the result of the
4378 conversion may be invalid. For example, if ARG3 has type
4379 "volatile X", and X does not have a copy constructor
4380 accepting a "volatile X&", then even if ARG2 can be
4381 converted to X, the conversion will fail. */
4382 if (error_operand_p (arg2))
4383 result = error_mark_node;
4385 else if (conv3 && (!conv3->bad_p || !conv2))
4387 arg3 = convert_like (conv3, arg3, complain);
4388 arg3 = convert_from_reference (arg3);
4389 arg3_type = TREE_TYPE (arg3);
4390 if (error_operand_p (arg3))
4391 result = error_mark_node;
4394 /* Free all the conversions we allocated. */
4395 obstack_free (&conversion_obstack, p);
4400 /* If, after the conversion, both operands have class type,
4401 treat the cv-qualification of both operands as if it were the
4402 union of the cv-qualification of the operands.
4404 The standard is not clear about what to do in this
4405 circumstance. For example, if the first operand has type
4406 "const X" and the second operand has a user-defined
4407 conversion to "volatile X", what is the type of the second
4408 operand after this step? Making it be "const X" (matching
4409 the first operand) seems wrong, as that discards the
4410 qualification without actually performing a copy. Leaving it
4411 as "volatile X" seems wrong as that will result in the
4412 conditional expression failing altogether, even though,
4413 according to this step, the one operand could be converted to
4414 the type of the other. */
4415 if ((conv2 || conv3)
4416 && CLASS_TYPE_P (arg2_type)
4417 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
4418 arg2_type = arg3_type =
4419 cp_build_qualified_type (arg2_type,
4420 cp_type_quals (arg2_type)
4421 | cp_type_quals (arg3_type));
4426 If the second and third operands are lvalues and have the same
4427 type, the result is of that type and is an lvalue. */
4428 if (real_lvalue_p (arg2)
4429 && real_lvalue_p (arg3)
4430 && same_type_p (arg2_type, arg3_type))
4432 result_type = arg2_type;
4433 arg2 = mark_lvalue_use (arg2);
4434 arg3 = mark_lvalue_use (arg3);
4435 goto valid_operands;
4440 Otherwise, the result is an rvalue. If the second and third
4441 operand do not have the same type, and either has (possibly
4442 cv-qualified) class type, overload resolution is used to
4443 determine the conversions (if any) to be applied to the operands
4444 (_over.match.oper_, _over.built_). */
4446 if (!same_type_p (arg2_type, arg3_type)
4447 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4453 /* Rearrange the arguments so that add_builtin_candidate only has
4454 to know about two args. In build_builtin_candidate, the
4455 arguments are unscrambled. */
4459 add_builtin_candidates (&candidates,
4462 ansi_opname (COND_EXPR),
4468 If the overload resolution fails, the program is
4470 candidates = splice_viable (candidates, pedantic, &any_viable_p);
4473 if (complain & tf_error)
4475 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4476 print_z_candidates (location_of (arg1), candidates);
4478 return error_mark_node;
4480 cand = tourney (candidates);
4483 if (complain & tf_error)
4485 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4486 print_z_candidates (location_of (arg1), candidates);
4488 return error_mark_node;
4493 Otherwise, the conversions thus determined are applied, and
4494 the converted operands are used in place of the original
4495 operands for the remainder of this section. */
4496 conv = cand->convs[0];
4497 arg1 = convert_like (conv, arg1, complain);
4498 conv = cand->convs[1];
4499 arg2 = convert_like (conv, arg2, complain);
4500 arg2_type = TREE_TYPE (arg2);
4501 conv = cand->convs[2];
4502 arg3 = convert_like (conv, arg3, complain);
4503 arg3_type = TREE_TYPE (arg3);
4508 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
4509 and function-to-pointer (_conv.func_) standard conversions are
4510 performed on the second and third operands.
4512 We need to force the lvalue-to-rvalue conversion here for class types,
4513 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
4514 that isn't wrapped with a TARGET_EXPR plays havoc with exception
4517 arg2 = force_rvalue (arg2, complain);
4518 if (!CLASS_TYPE_P (arg2_type))
4519 arg2_type = TREE_TYPE (arg2);
4521 arg3 = force_rvalue (arg3, complain);
4522 if (!CLASS_TYPE_P (arg3_type))
4523 arg3_type = TREE_TYPE (arg3);
4525 if (arg2 == error_mark_node || arg3 == error_mark_node)
4526 return error_mark_node;
4530 After those conversions, one of the following shall hold:
4532 --The second and third operands have the same type; the result is of
4534 if (same_type_p (arg2_type, arg3_type))
4535 result_type = arg2_type;
4538 --The second and third operands have arithmetic or enumeration
4539 type; the usual arithmetic conversions are performed to bring
4540 them to a common type, and the result is of that type. */
4541 else if ((ARITHMETIC_TYPE_P (arg2_type)
4542 || UNSCOPED_ENUM_P (arg2_type))
4543 && (ARITHMETIC_TYPE_P (arg3_type)
4544 || UNSCOPED_ENUM_P (arg3_type)))
4546 /* In this case, there is always a common type. */
4547 result_type = type_after_usual_arithmetic_conversions (arg2_type,
4549 do_warn_double_promotion (result_type, arg2_type, arg3_type,
4550 "implicit conversion from %qT to %qT to "
4551 "match other result of conditional",
4554 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
4555 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
4557 if (complain & tf_warning)
4559 "enumeral mismatch in conditional expression: %qT vs %qT",
4560 arg2_type, arg3_type);
4562 else if (extra_warnings
4563 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
4564 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
4565 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
4566 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
4568 if (complain & tf_warning)
4570 "enumeral and non-enumeral type in conditional expression");
4573 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4574 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4578 --The second and third operands have pointer type, or one has
4579 pointer type and the other is a null pointer constant; pointer
4580 conversions (_conv.ptr_) and qualification conversions
4581 (_conv.qual_) are performed to bring them to their composite
4582 pointer type (_expr.rel_). The result is of the composite
4585 --The second and third operands have pointer to member type, or
4586 one has pointer to member type and the other is a null pointer
4587 constant; pointer to member conversions (_conv.mem_) and
4588 qualification conversions (_conv.qual_) are performed to bring
4589 them to a common type, whose cv-qualification shall match the
4590 cv-qualification of either the second or the third operand.
4591 The result is of the common type. */
4592 else if ((null_ptr_cst_p (arg2)
4593 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
4594 || (null_ptr_cst_p (arg3)
4595 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
4596 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
4597 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
4598 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
4600 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
4601 arg3, CPO_CONDITIONAL_EXPR,
4603 if (result_type == error_mark_node)
4604 return error_mark_node;
4605 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4606 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4611 if (complain & tf_error)
4612 error ("operands to ?: have different types %qT and %qT",
4613 arg2_type, arg3_type);
4614 return error_mark_node;
4618 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3);
4619 if (!cp_unevaluated_operand)
4620 /* Avoid folding within decltype (c++/42013) and noexcept. */
4621 result = fold_if_not_in_template (result);
4623 /* We can't use result_type below, as fold might have returned a
4628 /* Expand both sides into the same slot, hopefully the target of
4629 the ?: expression. We used to check for TARGET_EXPRs here,
4630 but now we sometimes wrap them in NOP_EXPRs so the test would
4632 if (CLASS_TYPE_P (TREE_TYPE (result)))
4633 result = get_target_expr (result);
4634 /* If this expression is an rvalue, but might be mistaken for an
4635 lvalue, we must add a NON_LVALUE_EXPR. */
4636 result = rvalue (result);
4642 /* Wrapper for above. */
4645 build_conditional_expr (tree arg1, tree arg2, tree arg3,
4646 tsubst_flags_t complain)
4649 bool subtime = timevar_cond_start (TV_OVERLOAD);
4650 ret = build_conditional_expr_1 (arg1, arg2, arg3, complain);
4651 timevar_cond_stop (TV_OVERLOAD, subtime);
4655 /* OPERAND is an operand to an expression. Perform necessary steps
4656 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4660 prep_operand (tree operand)
4664 if (CLASS_TYPE_P (TREE_TYPE (operand))
4665 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
4666 /* Make sure the template type is instantiated now. */
4667 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
4673 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4674 OVERLOAD) to the CANDIDATES, returning an updated list of
4675 CANDIDATES. The ARGS are the arguments provided to the call;
4676 if FIRST_ARG is non-null it is the implicit object argument,
4677 otherwise the first element of ARGS is used if needed. The
4678 EXPLICIT_TARGS are explicit template arguments provided.
4679 TEMPLATE_ONLY is true if only template functions should be
4680 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4681 add_function_candidate. */
4684 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args,
4686 tree explicit_targs, bool template_only,
4687 tree conversion_path, tree access_path,
4689 struct z_candidate **candidates)
4692 const VEC(tree,gc) *non_static_args;
4693 bool check_list_ctor;
4694 bool check_converting;
4695 unification_kind_t strict;
4701 /* Precalculate special handling of constructors and conversion ops. */
4702 fn = OVL_CURRENT (fns);
4703 if (DECL_CONV_FN_P (fn))
4705 check_list_ctor = false;
4706 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4707 if (flags & LOOKUP_NO_CONVERSION)
4708 /* We're doing return_type(x). */
4709 strict = DEDUCE_CONV;
4711 /* We're doing x.operator return_type(). */
4712 strict = DEDUCE_EXACT;
4713 /* [over.match.funcs] For conversion functions, the function
4714 is considered to be a member of the class of the implicit
4715 object argument for the purpose of defining the type of
4716 the implicit object parameter. */
4717 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg)));
4721 if (DECL_CONSTRUCTOR_P (fn))
4723 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY);
4724 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4728 check_list_ctor = false;
4729 check_converting = false;
4731 strict = DEDUCE_CALL;
4732 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
4736 non_static_args = args;
4738 /* Delay creating the implicit this parameter until it is needed. */
4739 non_static_args = NULL;
4741 for (; fns; fns = OVL_NEXT (fns))
4744 const VEC(tree,gc) *fn_args;
4746 fn = OVL_CURRENT (fns);
4748 if (check_converting && DECL_NONCONVERTING_P (fn))
4750 if (check_list_ctor && !is_list_ctor (fn))
4753 /* Figure out which set of arguments to use. */
4754 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
4756 /* If this function is a non-static member and we didn't get an
4757 implicit object argument, move it out of args. */
4758 if (first_arg == NULL_TREE)
4762 VEC(tree,gc) *tempvec
4763 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1);
4764 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix)
4765 VEC_quick_push (tree, tempvec, arg);
4766 non_static_args = tempvec;
4767 first_arg = build_this (VEC_index (tree, args, 0));
4770 fn_first_arg = first_arg;
4771 fn_args = non_static_args;
4775 /* Otherwise, just use the list of arguments provided. */
4776 fn_first_arg = NULL_TREE;
4780 if (TREE_CODE (fn) == TEMPLATE_DECL)
4781 add_template_candidate (candidates,
4792 else if (!template_only)
4793 add_function_candidate (candidates,
4804 /* Even unsigned enum types promote to signed int. We don't want to
4805 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4806 original argument and ARG is the argument after any conversions
4807 have been applied. We set TREE_NO_WARNING if we have added a cast
4808 from an unsigned enum type to a signed integer type. */
4811 avoid_sign_compare_warnings (tree orig_arg, tree arg)
4813 if (orig_arg != NULL_TREE
4816 && TREE_CODE (TREE_TYPE (orig_arg)) == ENUMERAL_TYPE
4817 && TYPE_UNSIGNED (TREE_TYPE (orig_arg))
4818 && INTEGRAL_TYPE_P (TREE_TYPE (arg))
4819 && !TYPE_UNSIGNED (TREE_TYPE (arg)))
4820 TREE_NO_WARNING (arg) = 1;
4824 build_new_op_1 (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
4825 tree *overload, tsubst_flags_t complain)
4827 tree orig_arg1 = arg1;
4828 tree orig_arg2 = arg2;
4829 tree orig_arg3 = arg3;
4830 struct z_candidate *candidates = 0, *cand;
4831 VEC(tree,gc) *arglist;
4834 tree result = NULL_TREE;
4835 bool result_valid_p = false;
4836 enum tree_code code2 = NOP_EXPR;
4837 enum tree_code code_orig_arg1 = ERROR_MARK;
4838 enum tree_code code_orig_arg2 = ERROR_MARK;
4844 if (error_operand_p (arg1)
4845 || error_operand_p (arg2)
4846 || error_operand_p (arg3))
4847 return error_mark_node;
4849 if (code == MODIFY_EXPR)
4851 code2 = TREE_CODE (arg3);
4853 fnname = ansi_assopname (code2);
4856 fnname = ansi_opname (code);
4858 arg1 = prep_operand (arg1);
4864 case VEC_DELETE_EXPR:
4866 /* Use build_op_new_call and build_op_delete_call instead. */
4870 /* Use build_op_call instead. */
4873 case TRUTH_ORIF_EXPR:
4874 case TRUTH_ANDIF_EXPR:
4875 case TRUTH_AND_EXPR:
4877 /* These are saved for the sake of warn_logical_operator. */
4878 code_orig_arg1 = TREE_CODE (arg1);
4879 code_orig_arg2 = TREE_CODE (arg2);
4885 arg2 = prep_operand (arg2);
4886 arg3 = prep_operand (arg3);
4888 if (code == COND_EXPR)
4889 /* Use build_conditional_expr instead. */
4891 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
4892 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4895 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4896 arg2 = integer_zero_node;
4898 arglist = VEC_alloc (tree, gc, 3);
4899 VEC_quick_push (tree, arglist, arg1);
4900 if (arg2 != NULL_TREE)
4901 VEC_quick_push (tree, arglist, arg2);
4902 if (arg3 != NULL_TREE)
4903 VEC_quick_push (tree, arglist, arg3);
4905 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4906 p = conversion_obstack_alloc (0);
4908 /* Add namespace-scope operators to the list of functions to
4910 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4911 NULL_TREE, arglist, NULL_TREE,
4912 NULL_TREE, false, NULL_TREE, NULL_TREE,
4913 flags, &candidates);
4914 /* Add class-member operators to the candidate set. */
4915 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4919 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4920 if (fns == error_mark_node)
4922 result = error_mark_node;
4923 goto user_defined_result_ready;
4926 add_candidates (BASELINK_FUNCTIONS (fns),
4927 NULL_TREE, arglist, NULL_TREE,
4929 BASELINK_BINFO (fns),
4930 BASELINK_ACCESS_BINFO (fns),
4931 flags, &candidates);
4936 args[2] = NULL_TREE;
4938 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4944 /* For these, the built-in candidates set is empty
4945 [over.match.oper]/3. We don't want non-strict matches
4946 because exact matches are always possible with built-in
4947 operators. The built-in candidate set for COMPONENT_REF
4948 would be empty too, but since there are no such built-in
4949 operators, we accept non-strict matches for them. */
4954 strict_p = pedantic;
4958 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4963 case POSTINCREMENT_EXPR:
4964 case POSTDECREMENT_EXPR:
4965 /* Don't try anything fancy if we're not allowed to produce
4967 if (!(complain & tf_error))
4968 return error_mark_node;
4970 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4971 distinguish between prefix and postfix ++ and
4972 operator++() was used for both, so we allow this with
4974 if (flags & LOOKUP_COMPLAIN)
4976 const char *msg = (flag_permissive)
4977 ? G_("no %<%D(int)%> declared for postfix %qs,"
4978 " trying prefix operator instead")
4979 : G_("no %<%D(int)%> declared for postfix %qs");
4980 permerror (input_location, msg, fnname,
4981 operator_name_info[code].name);
4984 if (!flag_permissive)
4985 return error_mark_node;
4987 if (code == POSTINCREMENT_EXPR)
4988 code = PREINCREMENT_EXPR;
4990 code = PREDECREMENT_EXPR;
4991 result = build_new_op_1 (code, flags, arg1, NULL_TREE, NULL_TREE,
4992 overload, complain);
4995 /* The caller will deal with these. */
5000 result_valid_p = true;
5004 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
5006 /* If one of the arguments of the operator represents
5007 an invalid use of member function pointer, try to report
5008 a meaningful error ... */
5009 if (invalid_nonstatic_memfn_p (arg1, tf_error)
5010 || invalid_nonstatic_memfn_p (arg2, tf_error)
5011 || invalid_nonstatic_memfn_p (arg3, tf_error))
5012 /* We displayed the error message. */;
5015 /* ... Otherwise, report the more generic
5016 "no matching operator found" error */
5017 op_error (code, code2, arg1, arg2, arg3, FALSE);
5018 print_z_candidates (input_location, candidates);
5021 result = error_mark_node;
5027 cand = tourney (candidates);
5030 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
5032 op_error (code, code2, arg1, arg2, arg3, TRUE);
5033 print_z_candidates (input_location, candidates);
5035 result = error_mark_node;
5037 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
5040 *overload = cand->fn;
5042 if (resolve_args (arglist, complain) == NULL)
5043 result = error_mark_node;
5045 result = build_over_call (cand, LOOKUP_NORMAL, complain);
5049 /* Give any warnings we noticed during overload resolution. */
5050 if (cand->warnings && (complain & tf_warning))
5052 struct candidate_warning *w;
5053 for (w = cand->warnings; w; w = w->next)
5054 joust (cand, w->loser, 1);
5057 /* Check for comparison of different enum types. */
5066 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
5067 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
5068 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
5069 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
5070 && (complain & tf_warning))
5072 warning (OPT_Wenum_compare,
5073 "comparison between %q#T and %q#T",
5074 TREE_TYPE (arg1), TREE_TYPE (arg2));
5081 /* We need to strip any leading REF_BIND so that bitfields
5082 don't cause errors. This should not remove any important
5083 conversions, because builtins don't apply to class
5084 objects directly. */
5085 conv = cand->convs[0];
5086 if (conv->kind == ck_ref_bind)
5087 conv = conv->u.next;
5088 arg1 = convert_like (conv, arg1, complain);
5092 /* We need to call warn_logical_operator before
5093 converting arg2 to a boolean_type. */
5094 if (complain & tf_warning)
5095 warn_logical_operator (input_location, code, boolean_type_node,
5096 code_orig_arg1, arg1,
5097 code_orig_arg2, arg2);
5099 conv = cand->convs[1];
5100 if (conv->kind == ck_ref_bind)
5101 conv = conv->u.next;
5102 arg2 = convert_like (conv, arg2, complain);
5106 conv = cand->convs[2];
5107 if (conv->kind == ck_ref_bind)
5108 conv = conv->u.next;
5109 arg3 = convert_like (conv, arg3, complain);
5115 user_defined_result_ready:
5117 /* Free all the conversions we allocated. */
5118 obstack_free (&conversion_obstack, p);
5120 if (result || result_valid_p)
5124 avoid_sign_compare_warnings (orig_arg1, arg1);
5125 avoid_sign_compare_warnings (orig_arg2, arg2);
5126 avoid_sign_compare_warnings (orig_arg3, arg3);
5131 return cp_build_modify_expr (arg1, code2, arg2, complain);
5134 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
5136 case TRUTH_ANDIF_EXPR:
5137 case TRUTH_ORIF_EXPR:
5138 case TRUTH_AND_EXPR:
5140 warn_logical_operator (input_location, code, boolean_type_node,
5141 code_orig_arg1, arg1, code_orig_arg2, arg2);
5146 case TRUNC_DIV_EXPR:
5157 case TRUNC_MOD_EXPR:
5161 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
5163 case UNARY_PLUS_EXPR:
5166 case TRUTH_NOT_EXPR:
5167 case PREINCREMENT_EXPR:
5168 case POSTINCREMENT_EXPR:
5169 case PREDECREMENT_EXPR:
5170 case POSTDECREMENT_EXPR:
5173 return cp_build_unary_op (code, arg1, candidates != 0, complain);
5176 return cp_build_array_ref (input_location, arg1, arg2, complain);
5179 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL,
5183 /* The caller will deal with these. */
5195 /* Wrapper for above. */
5198 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
5199 tree *overload, tsubst_flags_t complain)
5202 bool subtime = timevar_cond_start (TV_OVERLOAD);
5203 ret = build_new_op_1 (code, flags, arg1, arg2, arg3, overload, complain);
5204 timevar_cond_stop (TV_OVERLOAD, subtime);
5208 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
5209 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
5212 non_placement_deallocation_fn_p (tree t)
5214 /* A template instance is never a usual deallocation function,
5215 regardless of its signature. */
5216 if (TREE_CODE (t) == TEMPLATE_DECL
5217 || primary_template_instantiation_p (t))
5220 /* If a class T has a member deallocation function named operator delete
5221 with exactly one parameter, then that function is a usual
5222 (non-placement) deallocation function. If class T does not declare
5223 such an operator delete but does declare a member deallocation
5224 function named operator delete with exactly two parameters, the second
5225 of which has type std::size_t (18.2), then this function is a usual
5226 deallocation function. */
5227 t = FUNCTION_ARG_CHAIN (t);
5228 if (t == void_list_node
5229 || (t && same_type_p (TREE_VALUE (t), size_type_node)
5230 && TREE_CHAIN (t) == void_list_node))
5235 /* Build a call to operator delete. This has to be handled very specially,
5236 because the restrictions on what signatures match are different from all
5237 other call instances. For a normal delete, only a delete taking (void *)
5238 or (void *, size_t) is accepted. For a placement delete, only an exact
5239 match with the placement new is accepted.
5241 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
5242 ADDR is the pointer to be deleted.
5243 SIZE is the size of the memory block to be deleted.
5244 GLOBAL_P is true if the delete-expression should not consider
5245 class-specific delete operators.
5246 PLACEMENT is the corresponding placement new call, or NULL_TREE.
5248 If this call to "operator delete" is being generated as part to
5249 deallocate memory allocated via a new-expression (as per [expr.new]
5250 which requires that if the initialization throws an exception then
5251 we call a deallocation function), then ALLOC_FN is the allocation
5255 build_op_delete_call (enum tree_code code, tree addr, tree size,
5256 bool global_p, tree placement,
5259 tree fn = NULL_TREE;
5260 tree fns, fnname, type, t;
5262 if (addr == error_mark_node)
5263 return error_mark_node;
5265 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
5267 fnname = ansi_opname (code);
5269 if (CLASS_TYPE_P (type)
5270 && COMPLETE_TYPE_P (complete_type (type))
5274 If the result of the lookup is ambiguous or inaccessible, or if
5275 the lookup selects a placement deallocation function, the
5276 program is ill-formed.
5278 Therefore, we ask lookup_fnfields to complain about ambiguity. */
5280 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
5281 if (fns == error_mark_node)
5282 return error_mark_node;
5287 if (fns == NULL_TREE)
5288 fns = lookup_name_nonclass (fnname);
5290 /* Strip const and volatile from addr. */
5291 addr = cp_convert (ptr_type_node, addr);
5295 /* "A declaration of a placement deallocation function matches the
5296 declaration of a placement allocation function if it has the same
5297 number of parameters and, after parameter transformations (8.3.5),
5298 all parameter types except the first are identical."
5300 So we build up the function type we want and ask instantiate_type
5301 to get it for us. */
5302 t = FUNCTION_ARG_CHAIN (alloc_fn);
5303 t = tree_cons (NULL_TREE, ptr_type_node, t);
5304 t = build_function_type (void_type_node, t);
5306 fn = instantiate_type (t, fns, tf_none);
5307 if (fn == error_mark_node)
5310 if (BASELINK_P (fn))
5311 fn = BASELINK_FUNCTIONS (fn);
5313 /* "If the lookup finds the two-parameter form of a usual deallocation
5314 function (3.7.4.2) and that function, considered as a placement
5315 deallocation function, would have been selected as a match for the
5316 allocation function, the program is ill-formed." */
5317 if (non_placement_deallocation_fn_p (fn))
5319 /* But if the class has an operator delete (void *), then that is
5320 the usual deallocation function, so we shouldn't complain
5321 about using the operator delete (void *, size_t). */
5322 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5323 t; t = OVL_NEXT (t))
5325 tree elt = OVL_CURRENT (t);
5326 if (non_placement_deallocation_fn_p (elt)
5327 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
5330 permerror (0, "non-placement deallocation function %q+D", fn);
5331 permerror (input_location, "selected for placement delete");
5336 /* "Any non-placement deallocation function matches a non-placement
5337 allocation function. If the lookup finds a single matching
5338 deallocation function, that function will be called; otherwise, no
5339 deallocation function will be called." */
5340 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5341 t; t = OVL_NEXT (t))
5343 tree elt = OVL_CURRENT (t);
5344 if (non_placement_deallocation_fn_p (elt))
5347 /* "If a class T has a member deallocation function named
5348 operator delete with exactly one parameter, then that
5349 function is a usual (non-placement) deallocation
5350 function. If class T does not declare such an operator
5351 delete but does declare a member deallocation function named
5352 operator delete with exactly two parameters, the second of
5353 which has type std::size_t (18.2), then this function is a
5354 usual deallocation function."
5356 So (void*) beats (void*, size_t). */
5357 if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
5362 /* If we have a matching function, call it. */
5365 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5367 /* If the FN is a member function, make sure that it is
5369 if (BASELINK_P (fns))
5370 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn);
5372 /* Core issue 901: It's ok to new a type with deleted delete. */
5373 if (DECL_DELETED_FN (fn) && alloc_fn)
5378 /* The placement args might not be suitable for overload
5379 resolution at this point, so build the call directly. */
5380 int nargs = call_expr_nargs (placement);
5381 tree *argarray = XALLOCAVEC (tree, nargs);
5384 for (i = 1; i < nargs; i++)
5385 argarray[i] = CALL_EXPR_ARG (placement, i);
5387 return build_cxx_call (fn, nargs, argarray);
5392 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2);
5393 VEC_quick_push (tree, args, addr);
5394 if (FUNCTION_ARG_CHAIN (fn) != void_list_node)
5395 VEC_quick_push (tree, args, size);
5396 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error);
5397 VEC_free (tree, gc, args);
5404 If no unambiguous matching deallocation function can be found,
5405 propagating the exception does not cause the object's memory to
5410 warning (0, "no corresponding deallocation function for %qD",
5415 error ("no suitable %<operator %s%> for %qT",
5416 operator_name_info[(int)code].name, type);
5417 return error_mark_node;
5420 /* If the current scope isn't allowed to access DECL along
5421 BASETYPE_PATH, give an error. The most derived class in
5422 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
5423 the declaration to use in the error diagnostic. */
5426 enforce_access (tree basetype_path, tree decl, tree diag_decl)
5428 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
5430 if (!accessible_p (basetype_path, decl, true))
5432 if (TREE_PRIVATE (decl))
5433 error ("%q+#D is private", diag_decl);
5434 else if (TREE_PROTECTED (decl))
5435 error ("%q+#D is protected", diag_decl);
5437 error ("%q+#D is inaccessible", diag_decl);
5438 error ("within this context");
5445 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
5446 bitwise or of LOOKUP_* values. If any errors are warnings are
5447 generated, set *DIAGNOSTIC_FN to "error" or "warning",
5448 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
5452 build_temp (tree expr, tree type, int flags,
5453 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
5458 savew = warningcount, savee = errorcount;
5459 args = make_tree_vector_single (expr);
5460 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
5461 &args, type, flags, complain);
5462 release_tree_vector (args);
5463 if (warningcount > savew)
5464 *diagnostic_kind = DK_WARNING;
5465 else if (errorcount > savee)
5466 *diagnostic_kind = DK_ERROR;
5468 *diagnostic_kind = DK_UNSPECIFIED;
5472 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
5473 EXPR is implicitly converted to type TOTYPE.
5474 FN and ARGNUM are used for diagnostics. */
5477 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
5479 tree t = non_reference (totype);
5481 /* Issue warnings about peculiar, but valid, uses of NULL. */
5482 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
5485 warning_at (input_location, OPT_Wconversion_null,
5486 "passing NULL to non-pointer argument %P of %qD",
5489 warning_at (input_location, OPT_Wconversion_null,
5490 "converting to non-pointer type %qT from NULL", t);
5493 /* Issue warnings if "false" is converted to a NULL pointer */
5494 else if (expr == boolean_false_node && POINTER_TYPE_P (t))
5497 warning_at (input_location, OPT_Wconversion_null,
5498 "converting %<false%> to pointer type for argument %P "
5499 "of %qD", argnum, fn);
5501 warning_at (input_location, OPT_Wconversion_null,
5502 "converting %<false%> to pointer type %qT", t);
5506 /* Perform the conversions in CONVS on the expression EXPR. FN and
5507 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
5508 indicates the `this' argument of a method. INNER is nonzero when
5509 being called to continue a conversion chain. It is negative when a
5510 reference binding will be applied, positive otherwise. If
5511 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
5512 conversions will be emitted if appropriate. If C_CAST_P is true,
5513 this conversion is coming from a C-style cast; in that case,
5514 conversions to inaccessible bases are permitted. */
5517 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
5518 int inner, bool issue_conversion_warnings,
5519 bool c_cast_p, tsubst_flags_t complain)
5521 tree totype = convs->type;
5522 diagnostic_t diag_kind;
5526 && convs->kind != ck_user
5527 && convs->kind != ck_list
5528 && convs->kind != ck_ambig
5529 && convs->kind != ck_ref_bind
5530 && convs->kind != ck_rvalue
5531 && convs->kind != ck_base)
5533 conversion *t = convs;
5535 /* Give a helpful error if this is bad because of excess braces. */
5536 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
5537 && SCALAR_TYPE_P (totype)
5538 && CONSTRUCTOR_NELTS (expr) > 0
5539 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
5540 permerror (input_location, "too many braces around initializer for %qT", totype);
5542 for (; t; t = convs->u.next)
5544 if (t->kind == ck_user && t->cand->reason)
5546 permerror (input_location, "invalid user-defined conversion "
5547 "from %qT to %qT", TREE_TYPE (expr), totype);
5548 print_z_candidate ("candidate is:", t->cand);
5549 expr = convert_like_real (t, expr, fn, argnum, 1,
5550 /*issue_conversion_warnings=*/false,
5553 return cp_convert (totype, expr);
5555 else if (t->kind == ck_user || !t->bad_p)
5557 expr = convert_like_real (t, expr, fn, argnum, 1,
5558 /*issue_conversion_warnings=*/false,
5563 else if (t->kind == ck_ambig)
5564 return convert_like_real (t, expr, fn, argnum, 1,
5565 /*issue_conversion_warnings=*/false,
5568 else if (t->kind == ck_identity)
5571 if (complain & tf_error)
5573 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
5575 permerror (DECL_SOURCE_LOCATION (fn),
5576 " initializing argument %P of %qD", argnum, fn);
5579 return error_mark_node;
5581 return cp_convert (totype, expr);
5584 if (issue_conversion_warnings && (complain & tf_warning))
5585 conversion_null_warnings (totype, expr, fn, argnum);
5587 switch (convs->kind)
5591 struct z_candidate *cand = convs->cand;
5592 tree convfn = cand->fn;
5595 /* If we're initializing from {}, it's value-initialization. */
5596 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
5597 && CONSTRUCTOR_NELTS (expr) == 0
5598 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
5600 expr = build_value_init (totype, complain);
5601 expr = get_target_expr_sfinae (expr, complain);
5602 if (expr != error_mark_node)
5603 TARGET_EXPR_LIST_INIT_P (expr) = true;
5607 expr = mark_rvalue_use (expr);
5609 /* When converting from an init list we consider explicit
5610 constructors, but actually trying to call one is an error. */
5611 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
5612 /* Unless we're calling it for value-initialization from an
5613 empty list, since that is handled separately in 8.5.4. */
5614 && cand->num_convs > 0)
5616 if (complain & tf_error)
5617 error ("converting to %qT from initializer list would use "
5618 "explicit constructor %qD", totype, convfn);
5620 return error_mark_node;
5623 /* Set user_conv_p on the argument conversions, so rvalue/base
5624 handling knows not to allow any more UDCs. */
5625 for (i = 0; i < cand->num_convs; ++i)
5626 cand->convs[i]->user_conv_p = true;
5628 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
5630 /* If this is a constructor or a function returning an aggr type,
5631 we need to build up a TARGET_EXPR. */
5632 if (DECL_CONSTRUCTOR_P (convfn))
5634 expr = build_cplus_new (totype, expr, complain);
5636 /* Remember that this was list-initialization. */
5637 if (convs->check_narrowing && expr != error_mark_node)
5638 TARGET_EXPR_LIST_INIT_P (expr) = true;
5644 expr = mark_rvalue_use (expr);
5645 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
5647 int nelts = CONSTRUCTOR_NELTS (expr);
5649 expr = build_value_init (totype, complain);
5650 else if (nelts == 1)
5651 expr = CONSTRUCTOR_ELT (expr, 0)->value;
5656 if (type_unknown_p (expr))
5657 expr = instantiate_type (totype, expr, complain);
5658 /* Convert a constant to its underlying value, unless we are
5659 about to bind it to a reference, in which case we need to
5660 leave it as an lvalue. */
5663 expr = decl_constant_value (expr);
5664 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
5665 /* If __null has been converted to an integer type, we do not
5666 want to warn about uses of EXPR as an integer, rather than
5668 expr = build_int_cst (totype, 0);
5672 if (complain & tf_error)
5674 /* Call build_user_type_conversion again for the error. */
5675 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL);
5677 error (" initializing argument %P of %q+D", argnum, fn);
5679 return error_mark_node;
5683 /* Conversion to std::initializer_list<T>. */
5684 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
5685 tree new_ctor = build_constructor (init_list_type_node, NULL);
5686 unsigned len = CONSTRUCTOR_NELTS (expr);
5687 tree array, val, field;
5688 VEC(constructor_elt,gc) *vec = NULL;
5691 /* Convert all the elements. */
5692 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
5694 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
5695 1, false, false, complain);
5696 if (sub == error_mark_node)
5698 if (!BRACE_ENCLOSED_INITIALIZER_P (val))
5699 check_narrowing (TREE_TYPE (sub), val);
5700 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
5701 if (!TREE_CONSTANT (sub))
5702 TREE_CONSTANT (new_ctor) = false;
5704 /* Build up the array. */
5705 elttype = cp_build_qualified_type
5706 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
5707 array = build_array_of_n_type (elttype, len);
5708 array = finish_compound_literal (array, new_ctor, complain);
5710 /* Build up the initializer_list object. */
5711 totype = complete_type (totype);
5712 field = next_initializable_field (TYPE_FIELDS (totype));
5713 CONSTRUCTOR_APPEND_ELT (vec, field, decay_conversion (array));
5714 field = next_initializable_field (DECL_CHAIN (field));
5715 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
5716 new_ctor = build_constructor (totype, vec);
5717 return get_target_expr (new_ctor);
5721 if (TREE_CODE (totype) == COMPLEX_TYPE)
5723 tree real = CONSTRUCTOR_ELT (expr, 0)->value;
5724 tree imag = CONSTRUCTOR_ELT (expr, 1)->value;
5725 real = perform_implicit_conversion (TREE_TYPE (totype),
5727 imag = perform_implicit_conversion (TREE_TYPE (totype),
5729 expr = build2 (COMPLEX_EXPR, totype, real, imag);
5730 return fold_if_not_in_template (expr);
5732 return get_target_expr (digest_init (totype, expr, complain));
5738 expr = convert_like_real (convs->u.next, expr, fn, argnum,
5739 convs->kind == ck_ref_bind ? -1 : 1,
5740 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
5743 if (expr == error_mark_node)
5744 return error_mark_node;
5746 switch (convs->kind)
5749 expr = decay_conversion (expr);
5750 if (! MAYBE_CLASS_TYPE_P (totype))
5752 /* Else fall through. */
5754 if (convs->kind == ck_base && !convs->need_temporary_p)
5756 /* We are going to bind a reference directly to a base-class
5757 subobject of EXPR. */
5758 /* Build an expression for `*((base*) &expr)'. */
5759 expr = cp_build_addr_expr (expr, complain);
5760 expr = convert_to_base (expr, build_pointer_type (totype),
5761 !c_cast_p, /*nonnull=*/true, complain);
5762 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain);
5766 /* Copy-initialization where the cv-unqualified version of the source
5767 type is the same class as, or a derived class of, the class of the
5768 destination [is treated as direct-initialization]. [dcl.init] */
5769 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
5770 if (convs->user_conv_p)
5771 /* This conversion is being done in the context of a user-defined
5772 conversion (i.e. the second step of copy-initialization), so
5773 don't allow any more. */
5774 flags |= LOOKUP_NO_CONVERSION;
5775 if (convs->rvaluedness_matches_p)
5776 flags |= LOOKUP_PREFER_RVALUE;
5777 if (TREE_CODE (expr) == TARGET_EXPR
5778 && TARGET_EXPR_LIST_INIT_P (expr))
5779 /* Copy-list-initialization doesn't actually involve a copy. */
5781 expr = build_temp (expr, totype, flags, &diag_kind, complain);
5782 if (diag_kind && fn)
5784 if ((complain & tf_error))
5785 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0,
5786 " initializing argument %P of %qD", argnum, fn);
5787 else if (diag_kind == DK_ERROR)
5788 return error_mark_node;
5790 return build_cplus_new (totype, expr, complain);
5794 tree ref_type = totype;
5796 if (convs->bad_p && TYPE_REF_IS_RVALUE (ref_type)
5797 && real_lvalue_p (expr))
5799 if (complain & tf_error)
5801 error ("cannot bind %qT lvalue to %qT",
5802 TREE_TYPE (expr), totype);
5804 error (" initializing argument %P of %q+D", argnum, fn);
5806 return error_mark_node;
5809 /* If necessary, create a temporary.
5811 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5812 that need temporaries, even when their types are reference
5813 compatible with the type of reference being bound, so the
5814 upcoming call to cp_build_addr_expr doesn't fail. */
5815 if (convs->need_temporary_p
5816 || TREE_CODE (expr) == CONSTRUCTOR
5817 || TREE_CODE (expr) == VA_ARG_EXPR)
5819 /* Otherwise, a temporary of type "cv1 T1" is created and
5820 initialized from the initializer expression using the rules
5821 for a non-reference copy-initialization (8.5). */
5823 tree type = TREE_TYPE (ref_type);
5824 cp_lvalue_kind lvalue = real_lvalue_p (expr);
5826 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5827 (type, convs->u.next->type));
5828 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
5829 && !TYPE_REF_IS_RVALUE (ref_type))
5831 if (complain & tf_error)
5833 /* If the reference is volatile or non-const, we
5834 cannot create a temporary. */
5835 if (lvalue & clk_bitfield)
5836 error ("cannot bind bitfield %qE to %qT",
5838 else if (lvalue & clk_packed)
5839 error ("cannot bind packed field %qE to %qT",
5842 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
5844 return error_mark_node;
5846 /* If the source is a packed field, and we must use a copy
5847 constructor, then building the target expr will require
5848 binding the field to the reference parameter to the
5849 copy constructor, and we'll end up with an infinite
5850 loop. If we can use a bitwise copy, then we'll be
5852 if ((lvalue & clk_packed)
5853 && CLASS_TYPE_P (type)
5854 && type_has_nontrivial_copy_init (type))
5856 if (complain & tf_error)
5857 error ("cannot bind packed field %qE to %qT",
5859 return error_mark_node;
5861 if (lvalue & clk_bitfield)
5863 expr = convert_bitfield_to_declared_type (expr);
5864 expr = fold_convert (type, expr);
5866 expr = build_target_expr_with_type (expr, type, complain);
5869 /* Take the address of the thing to which we will bind the
5871 expr = cp_build_addr_expr (expr, complain);
5872 if (expr == error_mark_node)
5873 return error_mark_node;
5875 /* Convert it to a pointer to the type referred to by the
5876 reference. This will adjust the pointer if a derived to
5877 base conversion is being performed. */
5878 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
5880 /* Convert the pointer to the desired reference type. */
5881 return build_nop (ref_type, expr);
5885 return decay_conversion (expr);
5888 /* Warn about deprecated conversion if appropriate. */
5889 string_conv_p (totype, expr, 1);
5894 expr = convert_to_base (expr, totype, !c_cast_p,
5895 /*nonnull=*/false, complain);
5896 return build_nop (totype, expr);
5899 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
5900 c_cast_p, complain);
5906 if (convs->check_narrowing)
5907 check_narrowing (totype, expr);
5909 if (issue_conversion_warnings && (complain & tf_warning))
5910 expr = convert_and_check (totype, expr);
5912 expr = convert (totype, expr);
5917 /* ARG is being passed to a varargs function. Perform any conversions
5918 required. Return the converted value. */
5921 convert_arg_to_ellipsis (tree arg)
5927 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5928 standard conversions are performed. */
5929 arg = decay_conversion (arg);
5930 arg_type = TREE_TYPE (arg);
5933 If the argument has integral or enumeration type that is subject
5934 to the integral promotions (_conv.prom_), or a floating point
5935 type that is subject to the floating point promotion
5936 (_conv.fpprom_), the value of the argument is converted to the
5937 promoted type before the call. */
5938 if (TREE_CODE (arg_type) == REAL_TYPE
5939 && (TYPE_PRECISION (arg_type)
5940 < TYPE_PRECISION (double_type_node))
5941 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
5943 if (warn_double_promotion && !c_inhibit_evaluation_warnings)
5944 warning (OPT_Wdouble_promotion,
5945 "implicit conversion from %qT to %qT when passing "
5946 "argument to function",
5947 arg_type, double_type_node);
5948 arg = convert_to_real (double_type_node, arg);
5950 else if (NULLPTR_TYPE_P (arg_type))
5951 arg = null_pointer_node;
5952 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
5954 if (SCOPED_ENUM_P (arg_type) && !abi_version_at_least (6))
5956 warning (OPT_Wabi, "scoped enum %qT will not promote to an "
5957 "integral type in a future version of GCC", arg_type);
5958 arg = cp_convert (ENUM_UNDERLYING_TYPE (arg_type), arg);
5960 arg = perform_integral_promotions (arg);
5963 arg = require_complete_type (arg);
5964 arg_type = TREE_TYPE (arg);
5966 if (arg != error_mark_node
5967 /* In a template (or ill-formed code), we can have an incomplete type
5968 even after require_complete_type, in which case we don't know
5969 whether it has trivial copy or not. */
5970 && COMPLETE_TYPE_P (arg_type))
5972 /* Build up a real lvalue-to-rvalue conversion in case the
5973 copy constructor is trivial but not callable. */
5974 if (CLASS_TYPE_P (arg_type))
5975 force_rvalue (arg, tf_warning_or_error);
5977 /* [expr.call] 5.2.2/7:
5978 Passing a potentially-evaluated argument of class type (Clause 9)
5979 with a non-trivial copy constructor or a non-trivial destructor
5980 with no corresponding parameter is conditionally-supported, with
5981 implementation-defined semantics.
5983 We used to just warn here and do a bitwise copy, but now
5984 cp_expr_size will abort if we try to do that.
5986 If the call appears in the context of a sizeof expression,
5987 it is not potentially-evaluated. */
5988 if (cp_unevaluated_operand == 0
5989 && (type_has_nontrivial_copy_init (arg_type)
5990 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
5991 error ("cannot pass objects of non-trivially-copyable "
5992 "type %q#T through %<...%>", arg_type);
5998 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
6001 build_x_va_arg (tree expr, tree type)
6003 if (processing_template_decl)
6004 return build_min (VA_ARG_EXPR, type, expr);
6006 type = complete_type_or_else (type, NULL_TREE);
6008 if (expr == error_mark_node || !type)
6009 return error_mark_node;
6011 expr = mark_lvalue_use (expr);
6013 if (type_has_nontrivial_copy_init (type)
6014 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
6015 || TREE_CODE (type) == REFERENCE_TYPE)
6017 /* Remove reference types so we don't ICE later on. */
6018 tree type1 = non_reference (type);
6019 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
6020 error ("cannot receive objects of non-trivially-copyable type %q#T "
6021 "through %<...%>; ", type);
6022 expr = convert (build_pointer_type (type1), null_node);
6023 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error);
6027 return build_va_arg (input_location, expr, type);
6030 /* TYPE has been given to va_arg. Apply the default conversions which
6031 would have happened when passed via ellipsis. Return the promoted
6032 type, or the passed type if there is no change. */
6035 cxx_type_promotes_to (tree type)
6039 /* Perform the array-to-pointer and function-to-pointer
6041 type = type_decays_to (type);
6043 promote = type_promotes_to (type);
6044 if (same_type_p (type, promote))
6050 /* ARG is a default argument expression being passed to a parameter of
6051 the indicated TYPE, which is a parameter to FN. PARMNUM is the
6052 zero-based argument number. Do any required conversions. Return
6053 the converted value. */
6055 static GTY(()) VEC(tree,gc) *default_arg_context;
6057 push_defarg_context (tree fn)
6058 { VEC_safe_push (tree, gc, default_arg_context, fn); }
6060 pop_defarg_context (void)
6061 { VEC_pop (tree, default_arg_context); }
6064 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
6069 /* See through clones. */
6070 fn = DECL_ORIGIN (fn);
6072 /* Detect recursion. */
6073 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t)
6076 error ("recursive evaluation of default argument for %q#D", fn);
6077 return error_mark_node;
6080 /* If the ARG is an unparsed default argument expression, the
6081 conversion cannot be performed. */
6082 if (TREE_CODE (arg) == DEFAULT_ARG)
6084 error ("call to %qD uses the default argument for parameter %P, which "
6085 "is not yet defined", fn, parmnum);
6086 return error_mark_node;
6089 push_defarg_context (fn);
6091 if (fn && DECL_TEMPLATE_INFO (fn))
6092 arg = tsubst_default_argument (fn, type, arg);
6098 The names in the expression are bound, and the semantic
6099 constraints are checked, at the point where the default
6100 expressions appears.
6102 we must not perform access checks here. */
6103 push_deferring_access_checks (dk_no_check);
6104 arg = break_out_target_exprs (arg);
6105 if (TREE_CODE (arg) == CONSTRUCTOR)
6107 arg = digest_init (type, arg, tf_warning_or_error);
6108 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
6109 ICR_DEFAULT_ARGUMENT, fn, parmnum,
6110 tf_warning_or_error);
6114 /* We must make a copy of ARG, in case subsequent processing
6115 alters any part of it. For example, during gimplification a
6116 cast of the form (T) &X::f (where "f" is a member function)
6117 will lead to replacing the PTRMEM_CST for &X::f with a
6118 VAR_DECL. We can avoid the copy for constants, since they
6119 are never modified in place. */
6120 if (!CONSTANT_CLASS_P (arg))
6121 arg = unshare_expr (arg);
6122 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
6123 ICR_DEFAULT_ARGUMENT, fn, parmnum,
6124 tf_warning_or_error);
6125 arg = convert_for_arg_passing (type, arg);
6127 pop_deferring_access_checks();
6129 pop_defarg_context ();
6134 /* Returns the type which will really be used for passing an argument of
6138 type_passed_as (tree type)
6140 /* Pass classes with copy ctors by invisible reference. */
6141 if (TREE_ADDRESSABLE (type))
6143 type = build_reference_type (type);
6144 /* There are no other pointers to this temporary. */
6145 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
6147 else if (targetm.calls.promote_prototypes (type)
6148 && INTEGRAL_TYPE_P (type)
6149 && COMPLETE_TYPE_P (type)
6150 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
6151 TYPE_SIZE (integer_type_node)))
6152 type = integer_type_node;
6157 /* Actually perform the appropriate conversion. */
6160 convert_for_arg_passing (tree type, tree val)
6164 /* If VAL is a bitfield, then -- since it has already been converted
6165 to TYPE -- it cannot have a precision greater than TYPE.
6167 If it has a smaller precision, we must widen it here. For
6168 example, passing "int f:3;" to a function expecting an "int" will
6169 not result in any conversion before this point.
6171 If the precision is the same we must not risk widening. For
6172 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
6173 often have type "int", even though the C++ type for the field is
6174 "long long". If the value is being passed to a function
6175 expecting an "int", then no conversions will be required. But,
6176 if we call convert_bitfield_to_declared_type, the bitfield will
6177 be converted to "long long". */
6178 bitfield_type = is_bitfield_expr_with_lowered_type (val);
6180 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
6181 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
6183 if (val == error_mark_node)
6185 /* Pass classes with copy ctors by invisible reference. */
6186 else if (TREE_ADDRESSABLE (type))
6187 val = build1 (ADDR_EXPR, build_reference_type (type), val);
6188 else if (targetm.calls.promote_prototypes (type)
6189 && INTEGRAL_TYPE_P (type)
6190 && COMPLETE_TYPE_P (type)
6191 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
6192 TYPE_SIZE (integer_type_node)))
6193 val = perform_integral_promotions (val);
6194 if (warn_missing_format_attribute)
6196 tree rhstype = TREE_TYPE (val);
6197 const enum tree_code coder = TREE_CODE (rhstype);
6198 const enum tree_code codel = TREE_CODE (type);
6199 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
6201 && check_missing_format_attribute (type, rhstype))
6202 warning (OPT_Wmissing_format_attribute,
6203 "argument of function call might be a candidate for a format attribute");
6208 /* Returns true iff FN is a function with magic varargs, i.e. ones for
6209 which no conversions at all should be done. This is true for some
6210 builtins which don't act like normal functions. */
6213 magic_varargs_p (tree fn)
6215 if (DECL_BUILT_IN (fn))
6216 switch (DECL_FUNCTION_CODE (fn))
6218 case BUILT_IN_CLASSIFY_TYPE:
6219 case BUILT_IN_CONSTANT_P:
6220 case BUILT_IN_NEXT_ARG:
6221 case BUILT_IN_VA_START:
6225 return lookup_attribute ("type generic",
6226 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
6232 /* Subroutine of the various build_*_call functions. Overload resolution
6233 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
6234 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
6235 bitmask of various LOOKUP_* flags which apply to the call itself. */
6238 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
6241 const VEC(tree,gc) *args = cand->args;
6242 tree first_arg = cand->first_arg;
6243 conversion **convs = cand->convs;
6245 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
6250 unsigned int arg_index = 0;
6254 bool already_used = false;
6256 /* In a template, there is no need to perform all of the work that
6257 is normally done. We are only interested in the type of the call
6258 expression, i.e., the return type of the function. Any semantic
6259 errors will be deferred until the template is instantiated. */
6260 if (processing_template_decl)
6264 const tree *argarray;
6267 return_type = TREE_TYPE (TREE_TYPE (fn));
6268 nargs = VEC_length (tree, args);
6269 if (first_arg == NULL_TREE)
6270 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args));
6278 alcarray = XALLOCAVEC (tree, nargs);
6279 alcarray[0] = first_arg;
6280 FOR_EACH_VEC_ELT (tree, args, ix, arg)
6281 alcarray[ix + 1] = arg;
6282 argarray = alcarray;
6284 expr = build_call_array_loc (input_location,
6285 return_type, build_addr_func (fn), nargs,
6287 if (TREE_THIS_VOLATILE (fn) && cfun)
6288 current_function_returns_abnormally = 1;
6289 return convert_from_reference (expr);
6292 /* Give any warnings we noticed during overload resolution. */
6293 if (cand->warnings && (complain & tf_warning))
6295 struct candidate_warning *w;
6296 for (w = cand->warnings; w; w = w->next)
6297 joust (cand, w->loser, 1);
6300 /* Make =delete work with SFINAE. */
6301 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
6302 return error_mark_node;
6304 if (DECL_FUNCTION_MEMBER_P (fn))
6307 /* If FN is a template function, two cases must be considered.
6312 template <class T> void f();
6314 template <class T> struct B {
6318 struct C : A, B<int> {
6320 using B<int>::g; // #2
6323 In case #1 where `A::f' is a member template, DECL_ACCESS is
6324 recorded in the primary template but not in its specialization.
6325 We check access of FN using its primary template.
6327 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
6328 because it is a member of class template B, DECL_ACCESS is
6329 recorded in the specialization `B<int>::g'. We cannot use its
6330 primary template because `B<T>::g' and `B<int>::g' may have
6331 different access. */
6332 if (DECL_TEMPLATE_INFO (fn)
6333 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
6334 access_fn = DECL_TI_TEMPLATE (fn);
6337 if (flags & LOOKUP_SPECULATIVE)
6339 if (!speculative_access_check (cand->access_path, access_fn, fn,
6340 !!(flags & LOOKUP_COMPLAIN)))
6341 return error_mark_node;
6344 perform_or_defer_access_check (cand->access_path, access_fn, fn);
6347 /* If we're checking for implicit delete, don't bother with argument
6349 if (flags & LOOKUP_SPECULATIVE)
6351 if (DECL_DELETED_FN (fn))
6353 if (flags & LOOKUP_COMPLAIN)
6355 return error_mark_node;
6357 if (cand->viable == 1)
6359 else if (!(flags & LOOKUP_COMPLAIN))
6360 /* Reject bad conversions now. */
6361 return error_mark_node;
6362 /* else continue to get conversion error. */
6365 /* Find maximum size of vector to hold converted arguments. */
6366 parmlen = list_length (parm);
6367 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0);
6368 if (parmlen > nargs)
6370 argarray = XALLOCAVEC (tree, nargs);
6372 /* The implicit parameters to a constructor are not considered by overload
6373 resolution, and must be of the proper type. */
6374 if (DECL_CONSTRUCTOR_P (fn))
6376 if (first_arg != NULL_TREE)
6378 argarray[j++] = first_arg;
6379 first_arg = NULL_TREE;
6383 argarray[j++] = VEC_index (tree, args, arg_index);
6386 parm = TREE_CHAIN (parm);
6387 /* We should never try to call the abstract constructor. */
6388 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
6390 if (DECL_HAS_VTT_PARM_P (fn))
6392 argarray[j++] = VEC_index (tree, args, arg_index);
6394 parm = TREE_CHAIN (parm);
6397 /* Bypass access control for 'this' parameter. */
6398 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6400 tree parmtype = TREE_VALUE (parm);
6401 tree arg = (first_arg != NULL_TREE
6403 : VEC_index (tree, args, arg_index));
6404 tree argtype = TREE_TYPE (arg);
6408 if (convs[i]->bad_p)
6410 if (complain & tf_error)
6411 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
6412 TREE_TYPE (argtype), fn);
6414 return error_mark_node;
6417 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
6418 X is called for an object that is not of type X, or of a type
6419 derived from X, the behavior is undefined.
6421 So we can assume that anything passed as 'this' is non-null, and
6422 optimize accordingly. */
6423 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
6424 /* Convert to the base in which the function was declared. */
6425 gcc_assert (cand->conversion_path != NULL_TREE);
6426 converted_arg = build_base_path (PLUS_EXPR,
6428 cand->conversion_path,
6430 /* Check that the base class is accessible. */
6431 if (!accessible_base_p (TREE_TYPE (argtype),
6432 BINFO_TYPE (cand->conversion_path), true))
6433 error ("%qT is not an accessible base of %qT",
6434 BINFO_TYPE (cand->conversion_path),
6435 TREE_TYPE (argtype));
6436 /* If fn was found by a using declaration, the conversion path
6437 will be to the derived class, not the base declaring fn. We
6438 must convert from derived to base. */
6439 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
6440 TREE_TYPE (parmtype), ba_unique, NULL);
6441 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
6444 argarray[j++] = converted_arg;
6445 parm = TREE_CHAIN (parm);
6446 if (first_arg != NULL_TREE)
6447 first_arg = NULL_TREE;
6454 gcc_assert (first_arg == NULL_TREE);
6455 for (; arg_index < VEC_length (tree, args) && parm;
6456 parm = TREE_CHAIN (parm), ++arg_index, ++i)
6458 tree type = TREE_VALUE (parm);
6459 tree arg = VEC_index (tree, args, arg_index);
6460 bool conversion_warning = true;
6464 /* If the argument is NULL and used to (implicitly) instantiate a
6465 template function (and bind one of the template arguments to
6466 the type of 'long int'), we don't want to warn about passing NULL
6467 to non-pointer argument.
6468 For example, if we have this template function:
6470 template<typename T> void func(T x) {}
6472 we want to warn (when -Wconversion is enabled) in this case:
6478 but not in this case:
6484 if (arg == null_node
6485 && DECL_TEMPLATE_INFO (fn)
6486 && cand->template_decl
6487 && !(flags & LOOKUP_EXPLICIT_TMPL_ARGS))
6488 conversion_warning = false;
6490 /* Warn about initializer_list deduction that isn't currently in the
6492 if (cxx_dialect > cxx98
6493 && flag_deduce_init_list
6494 && cand->template_decl
6495 && is_std_init_list (non_reference (type))
6496 && BRACE_ENCLOSED_INITIALIZER_P (arg))
6498 tree tmpl = TI_TEMPLATE (cand->template_decl);
6499 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
6500 tree patparm = get_pattern_parm (realparm, tmpl);
6501 tree pattype = TREE_TYPE (patparm);
6502 if (PACK_EXPANSION_P (pattype))
6503 pattype = PACK_EXPANSION_PATTERN (pattype);
6504 pattype = non_reference (pattype);
6506 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
6507 && (cand->explicit_targs == NULL_TREE
6508 || (TREE_VEC_LENGTH (cand->explicit_targs)
6509 <= TEMPLATE_TYPE_IDX (pattype))))
6511 pedwarn (input_location, 0, "deducing %qT as %qT",
6512 non_reference (TREE_TYPE (patparm)),
6513 non_reference (type));
6514 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
6515 pedwarn (input_location, 0,
6516 " (you can disable this with -fno-deduce-init-list)");
6520 val = convert_like_with_context (conv, arg, fn, i-is_method,
6523 : complain & (~tf_warning));
6525 val = convert_for_arg_passing (type, val);
6526 if (val == error_mark_node)
6527 return error_mark_node;
6529 argarray[j++] = val;
6532 /* Default arguments */
6533 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
6534 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
6535 TREE_PURPOSE (parm),
6538 for (; arg_index < VEC_length (tree, args); ++arg_index)
6540 tree a = VEC_index (tree, args, arg_index);
6541 if (magic_varargs_p (fn))
6542 /* Do no conversions for magic varargs. */
6543 a = mark_type_use (a);
6545 a = convert_arg_to_ellipsis (a);
6549 gcc_assert (j <= nargs);
6552 check_function_arguments (TREE_TYPE (fn), nargs, argarray);
6554 /* Avoid actually calling copy constructors and copy assignment operators,
6557 if (! flag_elide_constructors)
6558 /* Do things the hard way. */;
6559 else if (cand->num_convs == 1
6560 && (DECL_COPY_CONSTRUCTOR_P (fn)
6561 || DECL_MOVE_CONSTRUCTOR_P (fn)))
6564 tree arg = argarray[num_artificial_parms_for (fn)];
6566 bool trivial = trivial_fn_p (fn);
6568 /* Pull out the real argument, disregarding const-correctness. */
6570 while (CONVERT_EXPR_P (targ)
6571 || TREE_CODE (targ) == NON_LVALUE_EXPR)
6572 targ = TREE_OPERAND (targ, 0);
6573 if (TREE_CODE (targ) == ADDR_EXPR)
6575 targ = TREE_OPERAND (targ, 0);
6576 if (!same_type_ignoring_top_level_qualifiers_p
6577 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
6586 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6588 /* [class.copy]: the copy constructor is implicitly defined even if
6589 the implementation elided its use. */
6590 if (!trivial || DECL_DELETED_FN (fn))
6593 already_used = true;
6596 /* If we're creating a temp and we already have one, don't create a
6597 new one. If we're not creating a temp but we get one, use
6598 INIT_EXPR to collapse the temp into our target. Otherwise, if the
6599 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
6600 temp or an INIT_EXPR otherwise. */
6602 if (integer_zerop (fa))
6604 if (TREE_CODE (arg) == TARGET_EXPR)
6607 return force_target_expr (DECL_CONTEXT (fn), arg, complain);
6609 else if (TREE_CODE (arg) == TARGET_EXPR || trivial)
6611 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL,
6614 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
6618 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
6619 && trivial_fn_p (fn)
6620 && !DECL_DELETED_FN (fn))
6622 tree to = stabilize_reference
6623 (cp_build_indirect_ref (argarray[0], RO_NULL, complain));
6624 tree type = TREE_TYPE (to);
6625 tree as_base = CLASSTYPE_AS_BASE (type);
6626 tree arg = argarray[1];
6628 if (is_really_empty_class (type))
6630 /* Avoid copying empty classes. */
6631 val = build2 (COMPOUND_EXPR, void_type_node, to, arg);
6632 TREE_NO_WARNING (val) = 1;
6633 val = build2 (COMPOUND_EXPR, type, val, to);
6634 TREE_NO_WARNING (val) = 1;
6636 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
6638 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6639 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
6643 /* We must only copy the non-tail padding parts.
6644 Use __builtin_memcpy for the bitwise copy.
6645 FIXME fix 22488 so we can go back to using MODIFY_EXPR
6646 instead of an explicit call to memcpy. */
6648 tree arg0, arg1, arg2, t;
6649 tree test = NULL_TREE;
6651 arg2 = TYPE_SIZE_UNIT (as_base);
6653 arg0 = cp_build_addr_expr (to, complain);
6655 if (!can_trust_pointer_alignment ())
6657 /* If we can't be sure about pointer alignment, a call
6658 to __builtin_memcpy is expanded as a call to memcpy, which
6659 is invalid with identical args. Otherwise it is
6660 expanded as a block move, which should be safe. */
6661 arg0 = save_expr (arg0);
6662 arg1 = save_expr (arg1);
6663 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
6665 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
6666 t = build_call_n (t, 3, arg0, arg1, arg2);
6668 t = convert (TREE_TYPE (arg0), t);
6670 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
6671 val = cp_build_indirect_ref (t, RO_NULL, complain);
6672 TREE_NO_WARNING (val) = 1;
6677 else if (DECL_DESTRUCTOR_P (fn)
6678 && trivial_fn_p (fn)
6679 && !DECL_DELETED_FN (fn))
6680 return fold_convert (void_type_node, argarray[0]);
6681 /* FIXME handle trivial default constructor, too. */
6686 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
6689 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
6692 gcc_assert (binfo && binfo != error_mark_node);
6694 /* Warn about deprecated virtual functions now, since we're about
6695 to throw away the decl. */
6696 if (TREE_DEPRECATED (fn))
6697 warn_deprecated_use (fn, NULL_TREE);
6699 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
6700 if (TREE_SIDE_EFFECTS (argarray[0]))
6701 argarray[0] = save_expr (argarray[0]);
6702 t = build_pointer_type (TREE_TYPE (fn));
6703 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
6704 fn = build_java_interface_fn_ref (fn, argarray[0]);
6706 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
6710 fn = build_addr_func (fn);
6712 return build_cxx_call (fn, nargs, argarray);
6715 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
6716 This function performs no overload resolution, conversion, or other
6717 high-level operations. */
6720 build_cxx_call (tree fn, int nargs, tree *argarray)
6724 /* Remember roughly where this call is. */
6725 location_t loc = EXPR_LOC_OR_HERE (fn);
6726 fn = build_call_a (fn, nargs, argarray);
6727 SET_EXPR_LOCATION (fn, loc);
6729 /* If this call might throw an exception, note that fact. */
6730 fndecl = get_callee_fndecl (fn);
6732 /* Check that arguments to builtin functions match the expectations. */
6734 && DECL_BUILT_IN (fndecl)
6735 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6736 && !check_builtin_function_arguments (fndecl, nargs, argarray))
6737 return error_mark_node;
6739 /* Some built-in function calls will be evaluated at compile-time in
6741 fn = fold_if_not_in_template (fn);
6743 if (VOID_TYPE_P (TREE_TYPE (fn)))
6746 fn = require_complete_type (fn);
6747 if (fn == error_mark_node)
6748 return error_mark_node;
6750 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
6751 fn = build_cplus_new (TREE_TYPE (fn), fn, tf_warning_or_error);
6752 return convert_from_reference (fn);
6755 static GTY(()) tree java_iface_lookup_fn;
6757 /* Make an expression which yields the address of the Java interface
6758 method FN. This is achieved by generating a call to libjava's
6759 _Jv_LookupInterfaceMethodIdx(). */
6762 build_java_interface_fn_ref (tree fn, tree instance)
6764 tree lookup_fn, method, idx;
6765 tree klass_ref, iface, iface_ref;
6768 if (!java_iface_lookup_fn)
6770 tree ftype = build_function_type_list (ptr_type_node,
6771 ptr_type_node, ptr_type_node,
6772 java_int_type_node, NULL_TREE);
6773 java_iface_lookup_fn
6774 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype,
6775 0, NOT_BUILT_IN, NULL, NULL_TREE);
6778 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
6779 This is the first entry in the vtable. */
6780 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL,
6781 tf_warning_or_error),
6784 /* Get the java.lang.Class pointer for the interface being called. */
6785 iface = DECL_CONTEXT (fn);
6786 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
6787 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
6788 || DECL_CONTEXT (iface_ref) != iface)
6790 error ("could not find class$ field in java interface type %qT",
6792 return error_mark_node;
6794 iface_ref = build_address (iface_ref);
6795 iface_ref = convert (build_pointer_type (iface), iface_ref);
6797 /* Determine the itable index of FN. */
6799 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method))
6801 if (!DECL_VIRTUAL_P (method))
6807 idx = build_int_cst (NULL_TREE, i);
6809 lookup_fn = build1 (ADDR_EXPR,
6810 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
6811 java_iface_lookup_fn);
6812 return build_call_nary (ptr_type_node, lookup_fn,
6813 3, klass_ref, iface_ref, idx);
6816 /* Returns the value to use for the in-charge parameter when making a
6817 call to a function with the indicated NAME.
6819 FIXME:Can't we find a neater way to do this mapping? */
6822 in_charge_arg_for_name (tree name)
6824 if (name == base_ctor_identifier
6825 || name == base_dtor_identifier)
6826 return integer_zero_node;
6827 else if (name == complete_ctor_identifier)
6828 return integer_one_node;
6829 else if (name == complete_dtor_identifier)
6830 return integer_two_node;
6831 else if (name == deleting_dtor_identifier)
6832 return integer_three_node;
6834 /* This function should only be called with one of the names listed
6840 /* Build a call to a constructor, destructor, or an assignment
6841 operator for INSTANCE, an expression with class type. NAME
6842 indicates the special member function to call; *ARGS are the
6843 arguments. ARGS may be NULL. This may change ARGS. BINFO
6844 indicates the base of INSTANCE that is to be passed as the `this'
6845 parameter to the member function called.
6847 FLAGS are the LOOKUP_* flags to use when processing the call.
6849 If NAME indicates a complete object constructor, INSTANCE may be
6850 NULL_TREE. In this case, the caller will call build_cplus_new to
6851 store the newly constructed object into a VAR_DECL. */
6854 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args,
6855 tree binfo, int flags, tsubst_flags_t complain)
6858 /* The type of the subobject to be constructed or destroyed. */
6860 VEC(tree,gc) *allocated = NULL;
6863 gcc_assert (name == complete_ctor_identifier
6864 || name == base_ctor_identifier
6865 || name == complete_dtor_identifier
6866 || name == base_dtor_identifier
6867 || name == deleting_dtor_identifier
6868 || name == ansi_assopname (NOP_EXPR));
6871 /* Resolve the name. */
6872 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
6873 return error_mark_node;
6875 binfo = TYPE_BINFO (binfo);
6878 gcc_assert (binfo != NULL_TREE);
6880 class_type = BINFO_TYPE (binfo);
6882 /* Handle the special case where INSTANCE is NULL_TREE. */
6883 if (name == complete_ctor_identifier && !instance)
6885 instance = build_int_cst (build_pointer_type (class_type), 0);
6886 instance = build1 (INDIRECT_REF, class_type, instance);
6890 if (name == complete_dtor_identifier
6891 || name == base_dtor_identifier
6892 || name == deleting_dtor_identifier)
6893 gcc_assert (args == NULL || VEC_empty (tree, *args));
6895 /* Convert to the base class, if necessary. */
6896 if (!same_type_ignoring_top_level_qualifiers_p
6897 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
6899 if (name != ansi_assopname (NOP_EXPR))
6900 /* For constructors and destructors, either the base is
6901 non-virtual, or it is virtual but we are doing the
6902 conversion from a constructor or destructor for the
6903 complete object. In either case, we can convert
6905 instance = convert_to_base_statically (instance, binfo);
6907 /* However, for assignment operators, we must convert
6908 dynamically if the base is virtual. */
6909 instance = build_base_path (PLUS_EXPR, instance,
6910 binfo, /*nonnull=*/1);
6914 gcc_assert (instance != NULL_TREE);
6916 fns = lookup_fnfields (binfo, name, 1);
6918 /* When making a call to a constructor or destructor for a subobject
6919 that uses virtual base classes, pass down a pointer to a VTT for
6921 if ((name == base_ctor_identifier
6922 || name == base_dtor_identifier)
6923 && CLASSTYPE_VBASECLASSES (class_type))
6928 /* If the current function is a complete object constructor
6929 or destructor, then we fetch the VTT directly.
6930 Otherwise, we look it up using the VTT we were given. */
6931 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
6932 vtt = decay_conversion (vtt);
6933 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
6934 build2 (EQ_EXPR, boolean_type_node,
6935 current_in_charge_parm, integer_zero_node),
6938 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
6939 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
6940 BINFO_SUBVTT_INDEX (binfo));
6944 allocated = make_tree_vector ();
6948 VEC_safe_insert (tree, gc, *args, 0, sub_vtt);
6951 ret = build_new_method_call (instance, fns, args,
6952 TYPE_BINFO (BINFO_TYPE (binfo)),
6956 if (allocated != NULL)
6957 release_tree_vector (allocated);
6962 /* Return the NAME, as a C string. The NAME indicates a function that
6963 is a member of TYPE. *FREE_P is set to true if the caller must
6964 free the memory returned.
6966 Rather than go through all of this, we should simply set the names
6967 of constructors and destructors appropriately, and dispense with
6968 ctor_identifier, dtor_identifier, etc. */
6971 name_as_c_string (tree name, tree type, bool *free_p)
6975 /* Assume that we will not allocate memory. */
6977 /* Constructors and destructors are special. */
6978 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6981 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))));
6982 /* For a destructor, add the '~'. */
6983 if (name == complete_dtor_identifier
6984 || name == base_dtor_identifier
6985 || name == deleting_dtor_identifier)
6987 pretty_name = concat ("~", pretty_name, NULL);
6988 /* Remember that we need to free the memory allocated. */
6992 else if (IDENTIFIER_TYPENAME_P (name))
6994 pretty_name = concat ("operator ",
6995 type_as_string_translate (TREE_TYPE (name),
6996 TFF_PLAIN_IDENTIFIER),
6998 /* Remember that we need to free the memory allocated. */
7002 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name)));
7007 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
7008 be set, upon return, to the function called. ARGS may be NULL.
7009 This may change ARGS. */
7012 build_new_method_call_1 (tree instance, tree fns, VEC(tree,gc) **args,
7013 tree conversion_path, int flags,
7014 tree *fn_p, tsubst_flags_t complain)
7016 struct z_candidate *candidates = 0, *cand;
7017 tree explicit_targs = NULL_TREE;
7018 tree basetype = NULL_TREE;
7021 tree first_mem_arg = NULL_TREE;
7024 bool skip_first_for_error;
7025 VEC(tree,gc) *user_args;
7028 int template_only = 0;
7032 VEC(tree,gc) *orig_args = NULL;
7035 gcc_assert (instance != NULL_TREE);
7037 /* We don't know what function we're going to call, yet. */
7041 if (error_operand_p (instance)
7042 || !fns || error_operand_p (fns))
7043 return error_mark_node;
7045 if (!BASELINK_P (fns))
7047 if (complain & tf_error)
7048 error ("call to non-function %qD", fns);
7049 return error_mark_node;
7052 orig_instance = instance;
7055 /* Dismantle the baselink to collect all the information we need. */
7056 if (!conversion_path)
7057 conversion_path = BASELINK_BINFO (fns);
7058 access_binfo = BASELINK_ACCESS_BINFO (fns);
7059 optype = BASELINK_OPTYPE (fns);
7060 fns = BASELINK_FUNCTIONS (fns);
7061 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
7063 explicit_targs = TREE_OPERAND (fns, 1);
7064 fns = TREE_OPERAND (fns, 0);
7067 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
7068 || TREE_CODE (fns) == TEMPLATE_DECL
7069 || TREE_CODE (fns) == OVERLOAD);
7070 fn = get_first_fn (fns);
7071 name = DECL_NAME (fn);
7073 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
7074 gcc_assert (CLASS_TYPE_P (basetype));
7076 if (processing_template_decl)
7078 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
7079 instance = build_non_dependent_expr (instance);
7081 make_args_non_dependent (*args);
7084 user_args = args == NULL ? NULL : *args;
7085 /* Under DR 147 A::A() is an invalid constructor call,
7086 not a functional cast. */
7087 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
7089 if (! (complain & tf_error))
7090 return error_mark_node;
7092 permerror (input_location,
7093 "cannot call constructor %<%T::%D%> directly",
7095 permerror (input_location, " for a function-style cast, remove the "
7096 "redundant %<::%D%>", name);
7097 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
7102 /* Figure out whether to skip the first argument for the error
7103 message we will display to users if an error occurs. We don't
7104 want to display any compiler-generated arguments. The "this"
7105 pointer hasn't been added yet. However, we must remove the VTT
7106 pointer if this is a call to a base-class constructor or
7108 skip_first_for_error = false;
7109 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
7111 /* Callers should explicitly indicate whether they want to construct
7112 the complete object or just the part without virtual bases. */
7113 gcc_assert (name != ctor_identifier);
7114 /* Similarly for destructors. */
7115 gcc_assert (name != dtor_identifier);
7116 /* Remove the VTT pointer, if present. */
7117 if ((name == base_ctor_identifier || name == base_dtor_identifier)
7118 && CLASSTYPE_VBASECLASSES (basetype))
7119 skip_first_for_error = true;
7122 /* Process the argument list. */
7123 if (args != NULL && *args != NULL)
7125 *args = resolve_args (*args, complain);
7127 return error_mark_node;
7130 instance_ptr = build_this (instance);
7132 /* It's OK to call destructors and constructors on cv-qualified objects.
7133 Therefore, convert the INSTANCE_PTR to the unqualified type, if
7135 if (DECL_DESTRUCTOR_P (fn)
7136 || DECL_CONSTRUCTOR_P (fn))
7138 tree type = build_pointer_type (basetype);
7139 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
7140 instance_ptr = build_nop (type, instance_ptr);
7142 if (DECL_DESTRUCTOR_P (fn))
7143 name = complete_dtor_identifier;
7145 first_mem_arg = instance_ptr;
7147 /* Get the high-water mark for the CONVERSION_OBSTACK. */
7148 p = conversion_obstack_alloc (0);
7150 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
7151 initializer, not T({ }). */
7152 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args)
7153 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0))
7154 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0)))
7156 tree init_list = VEC_index (tree, *args, 0);
7158 gcc_assert (VEC_length (tree, *args) == 1
7159 && !(flags & LOOKUP_ONLYCONVERTING));
7161 /* If the initializer list has no elements and T is a class type with
7162 a default constructor, the object is value-initialized. Handle
7163 this here so we don't need to handle it wherever we use
7164 build_special_member_call. */
7165 if (CONSTRUCTOR_NELTS (init_list) == 0
7166 && TYPE_HAS_DEFAULT_CONSTRUCTOR (basetype)
7167 && !processing_template_decl)
7169 tree ob, init = build_value_init (basetype, complain);
7170 if (integer_zerop (instance_ptr))
7171 return get_target_expr_sfinae (init, complain);
7172 ob = build_fold_indirect_ref (instance_ptr);
7173 init = build2 (INIT_EXPR, TREE_TYPE (ob), ob, init);
7174 TREE_SIDE_EFFECTS (init) = true;
7178 add_list_candidates (fns, first_mem_arg, init_list,
7179 basetype, explicit_targs, template_only,
7180 conversion_path, access_binfo, flags, &candidates);
7184 add_candidates (fns, first_mem_arg, user_args, optype,
7185 explicit_targs, template_only, conversion_path,
7186 access_binfo, flags, &candidates);
7188 any_viable_p = false;
7189 candidates = splice_viable (candidates, pedantic, &any_viable_p);
7193 if (complain & tf_error)
7195 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
7196 cxx_incomplete_type_error (instance_ptr, basetype);
7198 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
7199 basetype, optype, build_tree_list_vec (user_args),
7200 TREE_TYPE (TREE_TYPE (instance_ptr)));
7207 pretty_name = name_as_c_string (name, basetype, &free_p);
7208 arglist = build_tree_list_vec (user_args);
7209 if (skip_first_for_error)
7210 arglist = TREE_CHAIN (arglist);
7211 error ("no matching function for call to %<%T::%s(%A)%#V%>",
7212 basetype, pretty_name, arglist,
7213 TREE_TYPE (TREE_TYPE (instance_ptr)));
7217 print_z_candidates (location_of (name), candidates);
7219 call = error_mark_node;
7223 cand = tourney (candidates);
7230 if (complain & tf_error)
7232 pretty_name = name_as_c_string (name, basetype, &free_p);
7233 arglist = build_tree_list_vec (user_args);
7234 if (skip_first_for_error)
7235 arglist = TREE_CHAIN (arglist);
7236 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
7238 print_z_candidates (location_of (name), candidates);
7242 call = error_mark_node;
7248 if (!(flags & LOOKUP_NONVIRTUAL)
7249 && DECL_PURE_VIRTUAL_P (fn)
7250 && instance == current_class_ref
7251 && (DECL_CONSTRUCTOR_P (current_function_decl)
7252 || DECL_DESTRUCTOR_P (current_function_decl))
7253 && (complain & tf_warning))
7254 /* This is not an error, it is runtime undefined
7256 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
7257 "pure virtual %q#D called from constructor"
7258 : "pure virtual %q#D called from destructor"),
7261 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
7262 && is_dummy_object (instance_ptr))
7264 if (complain & tf_error)
7265 error ("cannot call member function %qD without object",
7267 call = error_mark_node;
7271 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
7272 && resolves_to_fixed_type_p (instance, 0))
7273 flags |= LOOKUP_NONVIRTUAL;
7275 flags |= LOOKUP_EXPLICIT_TMPL_ARGS;
7276 /* Now we know what function is being called. */
7279 /* Build the actual CALL_EXPR. */
7280 call = build_over_call (cand, flags, complain);
7281 /* In an expression of the form `a->f()' where `f' turns
7282 out to be a static member function, `a' is
7283 none-the-less evaluated. */
7284 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
7285 && !is_dummy_object (instance_ptr)
7286 && TREE_SIDE_EFFECTS (instance_ptr))
7287 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
7288 instance_ptr, call);
7289 else if (call != error_mark_node
7290 && DECL_DESTRUCTOR_P (cand->fn)
7291 && !VOID_TYPE_P (TREE_TYPE (call)))
7292 /* An explicit call of the form "x->~X()" has type
7293 "void". However, on platforms where destructors
7294 return "this" (i.e., those where
7295 targetm.cxx.cdtor_returns_this is true), such calls
7296 will appear to have a return value of pointer type
7297 to the low-level call machinery. We do not want to
7298 change the low-level machinery, since we want to be
7299 able to optimize "delete f()" on such platforms as
7300 "operator delete(~X(f()))" (rather than generating
7301 "t = f(), ~X(t), operator delete (t)"). */
7302 call = build_nop (void_type_node, call);
7307 if (processing_template_decl && call != error_mark_node)
7309 bool cast_to_void = false;
7311 if (TREE_CODE (call) == COMPOUND_EXPR)
7312 call = TREE_OPERAND (call, 1);
7313 else if (TREE_CODE (call) == NOP_EXPR)
7315 cast_to_void = true;
7316 call = TREE_OPERAND (call, 0);
7318 if (TREE_CODE (call) == INDIRECT_REF)
7319 call = TREE_OPERAND (call, 0);
7320 call = (build_min_non_dep_call_vec
7322 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
7323 orig_instance, orig_fns, NULL_TREE),
7325 call = convert_from_reference (call);
7327 call = build_nop (void_type_node, call);
7330 /* Free all the conversions we allocated. */
7331 obstack_free (&conversion_obstack, p);
7333 if (orig_args != NULL)
7334 release_tree_vector (orig_args);
7339 /* Wrapper for above. */
7342 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args,
7343 tree conversion_path, int flags,
7344 tree *fn_p, tsubst_flags_t complain)
7347 bool subtime = timevar_cond_start (TV_OVERLOAD);
7348 ret = build_new_method_call_1 (instance, fns, args, conversion_path, flags,
7350 timevar_cond_stop (TV_OVERLOAD, subtime);
7354 /* Returns true iff standard conversion sequence ICS1 is a proper
7355 subsequence of ICS2. */
7358 is_subseq (conversion *ics1, conversion *ics2)
7360 /* We can assume that a conversion of the same code
7361 between the same types indicates a subsequence since we only get
7362 here if the types we are converting from are the same. */
7364 while (ics1->kind == ck_rvalue
7365 || ics1->kind == ck_lvalue)
7366 ics1 = ics1->u.next;
7370 while (ics2->kind == ck_rvalue
7371 || ics2->kind == ck_lvalue)
7372 ics2 = ics2->u.next;
7374 if (ics2->kind == ck_user
7375 || ics2->kind == ck_ambig
7376 || ics2->kind == ck_aggr
7377 || ics2->kind == ck_list
7378 || ics2->kind == ck_identity)
7379 /* At this point, ICS1 cannot be a proper subsequence of
7380 ICS2. We can get a USER_CONV when we are comparing the
7381 second standard conversion sequence of two user conversion
7385 ics2 = ics2->u.next;
7387 if (ics2->kind == ics1->kind
7388 && same_type_p (ics2->type, ics1->type)
7389 && same_type_p (ics2->u.next->type,
7390 ics1->u.next->type))
7395 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
7396 be any _TYPE nodes. */
7399 is_properly_derived_from (tree derived, tree base)
7401 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
7404 /* We only allow proper derivation here. The DERIVED_FROM_P macro
7405 considers every class derived from itself. */
7406 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
7407 && DERIVED_FROM_P (base, derived));
7410 /* We build the ICS for an implicit object parameter as a pointer
7411 conversion sequence. However, such a sequence should be compared
7412 as if it were a reference conversion sequence. If ICS is the
7413 implicit conversion sequence for an implicit object parameter,
7414 modify it accordingly. */
7417 maybe_handle_implicit_object (conversion **ics)
7421 /* [over.match.funcs]
7423 For non-static member functions, the type of the
7424 implicit object parameter is "reference to cv X"
7425 where X is the class of which the function is a
7426 member and cv is the cv-qualification on the member
7427 function declaration. */
7428 conversion *t = *ics;
7429 tree reference_type;
7431 /* The `this' parameter is a pointer to a class type. Make the
7432 implicit conversion talk about a reference to that same class
7434 reference_type = TREE_TYPE (t->type);
7435 reference_type = build_reference_type (reference_type);
7437 if (t->kind == ck_qual)
7439 if (t->kind == ck_ptr)
7441 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
7442 t = direct_reference_binding (reference_type, t);
7444 t->rvaluedness_matches_p = 0;
7449 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
7450 and return the initial reference binding conversion. Otherwise,
7451 leave *ICS unchanged and return NULL. */
7454 maybe_handle_ref_bind (conversion **ics)
7456 if ((*ics)->kind == ck_ref_bind)
7458 conversion *old_ics = *ics;
7459 *ics = old_ics->u.next;
7460 (*ics)->user_conv_p = old_ics->user_conv_p;
7467 /* Compare two implicit conversion sequences according to the rules set out in
7468 [over.ics.rank]. Return values:
7470 1: ics1 is better than ics2
7471 -1: ics2 is better than ics1
7472 0: ics1 and ics2 are indistinguishable */
7475 compare_ics (conversion *ics1, conversion *ics2)
7481 tree deref_from_type1 = NULL_TREE;
7482 tree deref_from_type2 = NULL_TREE;
7483 tree deref_to_type1 = NULL_TREE;
7484 tree deref_to_type2 = NULL_TREE;
7485 conversion_rank rank1, rank2;
7487 /* REF_BINDING is nonzero if the result of the conversion sequence
7488 is a reference type. In that case REF_CONV is the reference
7489 binding conversion. */
7490 conversion *ref_conv1;
7491 conversion *ref_conv2;
7493 /* Handle implicit object parameters. */
7494 maybe_handle_implicit_object (&ics1);
7495 maybe_handle_implicit_object (&ics2);
7497 /* Handle reference parameters. */
7498 ref_conv1 = maybe_handle_ref_bind (&ics1);
7499 ref_conv2 = maybe_handle_ref_bind (&ics2);
7501 /* List-initialization sequence L1 is a better conversion sequence than
7502 list-initialization sequence L2 if L1 converts to
7503 std::initializer_list<X> for some X and L2 does not. */
7504 if (ics1->kind == ck_list && ics2->kind != ck_list)
7506 if (ics2->kind == ck_list && ics1->kind != ck_list)
7511 When comparing the basic forms of implicit conversion sequences (as
7512 defined in _over.best.ics_)
7514 --a standard conversion sequence (_over.ics.scs_) is a better
7515 conversion sequence than a user-defined conversion sequence
7516 or an ellipsis conversion sequence, and
7518 --a user-defined conversion sequence (_over.ics.user_) is a
7519 better conversion sequence than an ellipsis conversion sequence
7520 (_over.ics.ellipsis_). */
7521 rank1 = CONVERSION_RANK (ics1);
7522 rank2 = CONVERSION_RANK (ics2);
7526 else if (rank1 < rank2)
7529 if (rank1 == cr_bad)
7531 /* Both ICS are bad. We try to make a decision based on what would
7532 have happened if they'd been good. This is not an extension,
7533 we'll still give an error when we build up the call; this just
7534 helps us give a more helpful error message. */
7535 rank1 = BAD_CONVERSION_RANK (ics1);
7536 rank2 = BAD_CONVERSION_RANK (ics2);
7540 else if (rank1 < rank2)
7543 /* We couldn't make up our minds; try to figure it out below. */
7546 if (ics1->ellipsis_p)
7547 /* Both conversions are ellipsis conversions. */
7550 /* User-defined conversion sequence U1 is a better conversion sequence
7551 than another user-defined conversion sequence U2 if they contain the
7552 same user-defined conversion operator or constructor and if the sec-
7553 ond standard conversion sequence of U1 is better than the second
7554 standard conversion sequence of U2. */
7556 /* Handle list-conversion with the same code even though it isn't always
7557 ranked as a user-defined conversion and it doesn't have a second
7558 standard conversion sequence; it will still have the desired effect.
7559 Specifically, we need to do the reference binding comparison at the
7560 end of this function. */
7562 if (ics1->user_conv_p || ics1->kind == ck_list)
7567 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
7568 if (t1->kind == ck_ambig || t1->kind == ck_aggr
7569 || t1->kind == ck_list)
7571 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
7572 if (t2->kind == ck_ambig || t2->kind == ck_aggr
7573 || t2->kind == ck_list)
7576 if (t1->kind != t2->kind)
7578 else if (t1->kind == ck_user)
7580 if (t1->cand->fn != t2->cand->fn)
7585 /* For ambiguous or aggregate conversions, use the target type as
7586 a proxy for the conversion function. */
7587 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
7591 /* We can just fall through here, after setting up
7592 FROM_TYPE1 and FROM_TYPE2. */
7593 from_type1 = t1->type;
7594 from_type2 = t2->type;
7601 /* We're dealing with two standard conversion sequences.
7605 Standard conversion sequence S1 is a better conversion
7606 sequence than standard conversion sequence S2 if
7608 --S1 is a proper subsequence of S2 (comparing the conversion
7609 sequences in the canonical form defined by _over.ics.scs_,
7610 excluding any Lvalue Transformation; the identity
7611 conversion sequence is considered to be a subsequence of
7612 any non-identity conversion sequence */
7615 while (t1->kind != ck_identity)
7617 from_type1 = t1->type;
7620 while (t2->kind != ck_identity)
7622 from_type2 = t2->type;
7625 /* One sequence can only be a subsequence of the other if they start with
7626 the same type. They can start with different types when comparing the
7627 second standard conversion sequence in two user-defined conversion
7629 if (same_type_p (from_type1, from_type2))
7631 if (is_subseq (ics1, ics2))
7633 if (is_subseq (ics2, ics1))
7641 --the rank of S1 is better than the rank of S2 (by the rules
7644 Standard conversion sequences are ordered by their ranks: an Exact
7645 Match is a better conversion than a Promotion, which is a better
7646 conversion than a Conversion.
7648 Two conversion sequences with the same rank are indistinguishable
7649 unless one of the following rules applies:
7651 --A conversion that does not a convert a pointer, pointer to member,
7652 or std::nullptr_t to bool is better than one that does.
7654 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
7655 so that we do not have to check it explicitly. */
7656 if (ics1->rank < ics2->rank)
7658 else if (ics2->rank < ics1->rank)
7661 to_type1 = ics1->type;
7662 to_type2 = ics2->type;
7664 /* A conversion from scalar arithmetic type to complex is worse than a
7665 conversion between scalar arithmetic types. */
7666 if (same_type_p (from_type1, from_type2)
7667 && ARITHMETIC_TYPE_P (from_type1)
7668 && ARITHMETIC_TYPE_P (to_type1)
7669 && ARITHMETIC_TYPE_P (to_type2)
7670 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
7671 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
7673 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
7679 if (TYPE_PTR_P (from_type1)
7680 && TYPE_PTR_P (from_type2)
7681 && TYPE_PTR_P (to_type1)
7682 && TYPE_PTR_P (to_type2))
7684 deref_from_type1 = TREE_TYPE (from_type1);
7685 deref_from_type2 = TREE_TYPE (from_type2);
7686 deref_to_type1 = TREE_TYPE (to_type1);
7687 deref_to_type2 = TREE_TYPE (to_type2);
7689 /* The rules for pointers to members A::* are just like the rules
7690 for pointers A*, except opposite: if B is derived from A then
7691 A::* converts to B::*, not vice versa. For that reason, we
7692 switch the from_ and to_ variables here. */
7693 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
7694 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
7695 || (TYPE_PTRMEMFUNC_P (from_type1)
7696 && TYPE_PTRMEMFUNC_P (from_type2)
7697 && TYPE_PTRMEMFUNC_P (to_type1)
7698 && TYPE_PTRMEMFUNC_P (to_type2)))
7700 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
7701 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
7702 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
7703 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
7706 if (deref_from_type1 != NULL_TREE
7707 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
7708 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
7710 /* This was one of the pointer or pointer-like conversions.
7714 --If class B is derived directly or indirectly from class A,
7715 conversion of B* to A* is better than conversion of B* to
7716 void*, and conversion of A* to void* is better than
7717 conversion of B* to void*. */
7718 if (TREE_CODE (deref_to_type1) == VOID_TYPE
7719 && TREE_CODE (deref_to_type2) == VOID_TYPE)
7721 if (is_properly_derived_from (deref_from_type1,
7724 else if (is_properly_derived_from (deref_from_type2,
7728 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
7729 || TREE_CODE (deref_to_type2) == VOID_TYPE)
7731 if (same_type_p (deref_from_type1, deref_from_type2))
7733 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
7735 if (is_properly_derived_from (deref_from_type1,
7739 /* We know that DEREF_TO_TYPE1 is `void' here. */
7740 else if (is_properly_derived_from (deref_from_type1,
7745 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
7746 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
7750 --If class B is derived directly or indirectly from class A
7751 and class C is derived directly or indirectly from B,
7753 --conversion of C* to B* is better than conversion of C* to
7756 --conversion of B* to A* is better than conversion of C* to
7758 if (same_type_p (deref_from_type1, deref_from_type2))
7760 if (is_properly_derived_from (deref_to_type1,
7763 else if (is_properly_derived_from (deref_to_type2,
7767 else if (same_type_p (deref_to_type1, deref_to_type2))
7769 if (is_properly_derived_from (deref_from_type2,
7772 else if (is_properly_derived_from (deref_from_type1,
7778 else if (CLASS_TYPE_P (non_reference (from_type1))
7779 && same_type_p (from_type1, from_type2))
7781 tree from = non_reference (from_type1);
7785 --binding of an expression of type C to a reference of type
7786 B& is better than binding an expression of type C to a
7787 reference of type A&
7789 --conversion of C to B is better than conversion of C to A, */
7790 if (is_properly_derived_from (from, to_type1)
7791 && is_properly_derived_from (from, to_type2))
7793 if (is_properly_derived_from (to_type1, to_type2))
7795 else if (is_properly_derived_from (to_type2, to_type1))
7799 else if (CLASS_TYPE_P (non_reference (to_type1))
7800 && same_type_p (to_type1, to_type2))
7802 tree to = non_reference (to_type1);
7806 --binding of an expression of type B to a reference of type
7807 A& is better than binding an expression of type C to a
7808 reference of type A&,
7810 --conversion of B to A is better than conversion of C to A */
7811 if (is_properly_derived_from (from_type1, to)
7812 && is_properly_derived_from (from_type2, to))
7814 if (is_properly_derived_from (from_type2, from_type1))
7816 else if (is_properly_derived_from (from_type1, from_type2))
7823 --S1 and S2 differ only in their qualification conversion and yield
7824 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
7825 qualification signature of type T1 is a proper subset of the cv-
7826 qualification signature of type T2 */
7827 if (ics1->kind == ck_qual
7828 && ics2->kind == ck_qual
7829 && same_type_p (from_type1, from_type2))
7831 int result = comp_cv_qual_signature (to_type1, to_type2);
7838 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
7839 to an implicit object parameter, and either S1 binds an lvalue reference
7840 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
7841 reference to an rvalue and S2 binds an lvalue reference
7842 (C++0x draft standard, 13.3.3.2)
7844 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
7845 types to which the references refer are the same type except for
7846 top-level cv-qualifiers, and the type to which the reference
7847 initialized by S2 refers is more cv-qualified than the type to
7848 which the reference initialized by S1 refers */
7850 if (ref_conv1 && ref_conv2)
7852 if (!ref_conv1->this_p && !ref_conv2->this_p
7853 && (TYPE_REF_IS_RVALUE (ref_conv1->type)
7854 != TYPE_REF_IS_RVALUE (ref_conv2->type)))
7856 if (ref_conv1->rvaluedness_matches_p)
7858 if (ref_conv2->rvaluedness_matches_p)
7862 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
7863 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
7864 TREE_TYPE (ref_conv1->type));
7867 /* Neither conversion sequence is better than the other. */
7871 /* The source type for this standard conversion sequence. */
7874 source_type (conversion *t)
7876 for (;; t = t->u.next)
7878 if (t->kind == ck_user
7879 || t->kind == ck_ambig
7880 || t->kind == ck_identity)
7886 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7887 a pointer to LOSER and re-running joust to produce the warning if WINNER
7888 is actually used. */
7891 add_warning (struct z_candidate *winner, struct z_candidate *loser)
7893 candidate_warning *cw = (candidate_warning *)
7894 conversion_obstack_alloc (sizeof (candidate_warning));
7896 cw->next = winner->warnings;
7897 winner->warnings = cw;
7900 /* Compare two candidates for overloading as described in
7901 [over.match.best]. Return values:
7903 1: cand1 is better than cand2
7904 -1: cand2 is better than cand1
7905 0: cand1 and cand2 are indistinguishable */
7908 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
7911 int off1 = 0, off2 = 0;
7915 /* Candidates that involve bad conversions are always worse than those
7917 if (cand1->viable > cand2->viable)
7919 if (cand1->viable < cand2->viable)
7922 /* If we have two pseudo-candidates for conversions to the same type,
7923 or two candidates for the same function, arbitrarily pick one. */
7924 if (cand1->fn == cand2->fn
7925 && (IS_TYPE_OR_DECL_P (cand1->fn)))
7928 /* a viable function F1
7929 is defined to be a better function than another viable function F2 if
7930 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7931 ICSi(F2), and then */
7933 /* for some argument j, ICSj(F1) is a better conversion sequence than
7936 /* For comparing static and non-static member functions, we ignore
7937 the implicit object parameter of the non-static function. The
7938 standard says to pretend that the static function has an object
7939 parm, but that won't work with operator overloading. */
7940 len = cand1->num_convs;
7941 if (len != cand2->num_convs)
7943 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
7944 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
7946 gcc_assert (static_1 != static_2);
7957 for (i = 0; i < len; ++i)
7959 conversion *t1 = cand1->convs[i + off1];
7960 conversion *t2 = cand2->convs[i + off2];
7961 int comp = compare_ics (t1, t2);
7966 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
7967 == cr_std + cr_promotion)
7968 && t1->kind == ck_std
7969 && t2->kind == ck_std
7970 && TREE_CODE (t1->type) == INTEGER_TYPE
7971 && TREE_CODE (t2->type) == INTEGER_TYPE
7972 && (TYPE_PRECISION (t1->type)
7973 == TYPE_PRECISION (t2->type))
7974 && (TYPE_UNSIGNED (t1->u.next->type)
7975 || (TREE_CODE (t1->u.next->type)
7978 tree type = t1->u.next->type;
7980 struct z_candidate *w, *l;
7982 type1 = t1->type, type2 = t2->type,
7983 w = cand1, l = cand2;
7985 type1 = t2->type, type2 = t1->type,
7986 w = cand2, l = cand1;
7990 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
7991 type, type1, type2);
7992 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
7998 if (winner && comp != winner)
8007 /* warn about confusing overload resolution for user-defined conversions,
8008 either between a constructor and a conversion op, or between two
8010 if (winner && warn_conversion && cand1->second_conv
8011 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
8012 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
8014 struct z_candidate *w, *l;
8015 bool give_warning = false;
8018 w = cand1, l = cand2;
8020 w = cand2, l = cand1;
8022 /* We don't want to complain about `X::operator T1 ()'
8023 beating `X::operator T2 () const', when T2 is a no less
8024 cv-qualified version of T1. */
8025 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
8026 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
8028 tree t = TREE_TYPE (TREE_TYPE (l->fn));
8029 tree f = TREE_TYPE (TREE_TYPE (w->fn));
8031 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
8036 if (!comp_ptr_ttypes (t, f))
8037 give_warning = true;
8040 give_warning = true;
8046 tree source = source_type (w->convs[0]);
8047 if (! DECL_CONSTRUCTOR_P (w->fn))
8048 source = TREE_TYPE (source);
8049 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
8050 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
8051 source, w->second_conv->type))
8053 inform (input_location, " because conversion sequence for the argument is better");
8064 F1 is a non-template function and F2 is a template function
8067 if (!cand1->template_decl && cand2->template_decl)
8069 else if (cand1->template_decl && !cand2->template_decl)
8073 F1 and F2 are template functions and the function template for F1 is
8074 more specialized than the template for F2 according to the partial
8077 if (cand1->template_decl && cand2->template_decl)
8079 winner = more_specialized_fn
8080 (TI_TEMPLATE (cand1->template_decl),
8081 TI_TEMPLATE (cand2->template_decl),
8082 /* [temp.func.order]: The presence of unused ellipsis and default
8083 arguments has no effect on the partial ordering of function
8084 templates. add_function_candidate() will not have
8085 counted the "this" argument for constructors. */
8086 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
8092 the context is an initialization by user-defined conversion (see
8093 _dcl.init_ and _over.match.user_) and the standard conversion
8094 sequence from the return type of F1 to the destination type (i.e.,
8095 the type of the entity being initialized) is a better conversion
8096 sequence than the standard conversion sequence from the return type
8097 of F2 to the destination type. */
8099 if (cand1->second_conv)
8101 winner = compare_ics (cand1->second_conv, cand2->second_conv);
8106 /* Check whether we can discard a builtin candidate, either because we
8107 have two identical ones or matching builtin and non-builtin candidates.
8109 (Pedantically in the latter case the builtin which matched the user
8110 function should not be added to the overload set, but we spot it here.
8113 ... the builtin candidates include ...
8114 - do not have the same parameter type list as any non-template
8115 non-member candidate. */
8117 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
8118 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
8120 for (i = 0; i < len; ++i)
8121 if (!same_type_p (cand1->convs[i]->type,
8122 cand2->convs[i]->type))
8124 if (i == cand1->num_convs)
8126 if (cand1->fn == cand2->fn)
8127 /* Two built-in candidates; arbitrarily pick one. */
8129 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
8130 /* cand1 is built-in; prefer cand2. */
8133 /* cand2 is built-in; prefer cand1. */
8138 /* If the two function declarations represent the same function (this can
8139 happen with declarations in multiple scopes and arg-dependent lookup),
8140 arbitrarily choose one. But first make sure the default args we're
8142 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
8143 && equal_functions (cand1->fn, cand2->fn))
8145 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
8146 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
8148 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
8150 for (i = 0; i < len; ++i)
8152 /* Don't crash if the fn is variadic. */
8155 parms1 = TREE_CHAIN (parms1);
8156 parms2 = TREE_CHAIN (parms2);
8160 parms1 = TREE_CHAIN (parms1);
8162 parms2 = TREE_CHAIN (parms2);
8166 if (!cp_tree_equal (TREE_PURPOSE (parms1),
8167 TREE_PURPOSE (parms2)))
8171 permerror (input_location, "default argument mismatch in "
8172 "overload resolution");
8173 inform (input_location,
8174 " candidate 1: %q+#F", cand1->fn);
8175 inform (input_location,
8176 " candidate 2: %q+#F", cand2->fn);
8179 add_warning (cand1, cand2);
8182 parms1 = TREE_CHAIN (parms1);
8183 parms2 = TREE_CHAIN (parms2);
8191 /* Extension: If the worst conversion for one candidate is worse than the
8192 worst conversion for the other, take the first. */
8195 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
8196 struct z_candidate *w = 0, *l = 0;
8198 for (i = 0; i < len; ++i)
8200 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
8201 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
8202 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
8203 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
8206 winner = 1, w = cand1, l = cand2;
8208 winner = -1, w = cand2, l = cand1;
8211 /* Don't choose a deleted function over ambiguity. */
8212 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
8216 pedwarn (input_location, 0,
8217 "ISO C++ says that these are ambiguous, even "
8218 "though the worst conversion for the first is better than "
8219 "the worst conversion for the second:");
8220 print_z_candidate (_("candidate 1:"), w);
8221 print_z_candidate (_("candidate 2:"), l);
8229 gcc_assert (!winner);
8233 /* Given a list of candidates for overloading, find the best one, if any.
8234 This algorithm has a worst case of O(2n) (winner is last), and a best
8235 case of O(n/2) (totally ambiguous); much better than a sorting
8238 static struct z_candidate *
8239 tourney (struct z_candidate *candidates)
8241 struct z_candidate *champ = candidates, *challenger;
8243 int champ_compared_to_predecessor = 0;
8245 /* Walk through the list once, comparing each current champ to the next
8246 candidate, knocking out a candidate or two with each comparison. */
8248 for (challenger = champ->next; challenger; )
8250 fate = joust (champ, challenger, 0);
8252 challenger = challenger->next;
8257 champ = challenger->next;
8260 champ_compared_to_predecessor = 0;
8265 champ_compared_to_predecessor = 1;
8268 challenger = champ->next;
8272 /* Make sure the champ is better than all the candidates it hasn't yet
8273 been compared to. */
8275 for (challenger = candidates;
8277 && !(champ_compared_to_predecessor && challenger->next == champ);
8278 challenger = challenger->next)
8280 fate = joust (champ, challenger, 0);
8288 /* Returns nonzero if things of type FROM can be converted to TO. */
8291 can_convert (tree to, tree from)
8293 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT);
8296 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
8299 can_convert_arg (tree to, tree from, tree arg, int flags)
8305 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8306 p = conversion_obstack_alloc (0);
8308 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8310 ok_p = (t && !t->bad_p);
8312 /* Free all the conversions we allocated. */
8313 obstack_free (&conversion_obstack, p);
8318 /* Like can_convert_arg, but allows dubious conversions as well. */
8321 can_convert_arg_bad (tree to, tree from, tree arg, int flags)
8326 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8327 p = conversion_obstack_alloc (0);
8328 /* Try to perform the conversion. */
8329 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8331 /* Free all the conversions we allocated. */
8332 obstack_free (&conversion_obstack, p);
8337 /* Convert EXPR to TYPE. Return the converted expression.
8339 Note that we allow bad conversions here because by the time we get to
8340 this point we are committed to doing the conversion. If we end up
8341 doing a bad conversion, convert_like will complain. */
8344 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags)
8349 if (error_operand_p (expr))
8350 return error_mark_node;
8352 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8353 p = conversion_obstack_alloc (0);
8355 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8361 if (complain & tf_error)
8363 /* If expr has unknown type, then it is an overloaded function.
8364 Call instantiate_type to get good error messages. */
8365 if (TREE_TYPE (expr) == unknown_type_node)
8366 instantiate_type (type, expr, complain);
8367 else if (invalid_nonstatic_memfn_p (expr, complain))
8368 /* We gave an error. */;
8370 error ("could not convert %qE from %qT to %qT", expr,
8371 TREE_TYPE (expr), type);
8373 expr = error_mark_node;
8375 else if (processing_template_decl)
8377 /* In a template, we are only concerned about determining the
8378 type of non-dependent expressions, so we do not have to
8379 perform the actual conversion. */
8380 if (TREE_TYPE (expr) != type)
8381 expr = build_nop (type, expr);
8384 expr = convert_like (conv, expr, complain);
8386 /* Free all the conversions we allocated. */
8387 obstack_free (&conversion_obstack, p);
8393 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
8395 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT);
8398 /* Convert EXPR to TYPE (as a direct-initialization) if that is
8399 permitted. If the conversion is valid, the converted expression is
8400 returned. Otherwise, NULL_TREE is returned, except in the case
8401 that TYPE is a class type; in that case, an error is issued. If
8402 C_CAST_P is true, then this direct-initialization is taking
8403 place as part of a static_cast being attempted as part of a C-style
8407 perform_direct_initialization_if_possible (tree type,
8410 tsubst_flags_t complain)
8415 if (type == error_mark_node || error_operand_p (expr))
8416 return error_mark_node;
8419 If the destination type is a (possibly cv-qualified) class type:
8421 -- If the initialization is direct-initialization ...,
8422 constructors are considered. ... If no constructor applies, or
8423 the overload resolution is ambiguous, the initialization is
8425 if (CLASS_TYPE_P (type))
8427 VEC(tree,gc) *args = make_tree_vector_single (expr);
8428 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
8429 &args, type, LOOKUP_NORMAL, complain);
8430 release_tree_vector (args);
8431 return build_cplus_new (type, expr, complain);
8434 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8435 p = conversion_obstack_alloc (0);
8437 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8440 if (!conv || conv->bad_p)
8443 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
8444 /*issue_conversion_warnings=*/false,
8448 /* Free all the conversions we allocated. */
8449 obstack_free (&conversion_obstack, p);
8454 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
8455 is being bound to a temporary. Create and return a new VAR_DECL
8456 with the indicated TYPE; this variable will store the value to
8457 which the reference is bound. */
8460 make_temporary_var_for_ref_to_temp (tree decl, tree type)
8464 /* Create the variable. */
8465 var = create_temporary_var (type);
8467 /* Register the variable. */
8468 if (TREE_STATIC (decl))
8470 /* Namespace-scope or local static; give it a mangled name. */
8473 TREE_STATIC (var) = 1;
8474 name = mangle_ref_init_variable (decl);
8475 DECL_NAME (var) = name;
8476 SET_DECL_ASSEMBLER_NAME (var, name);
8477 var = pushdecl_top_level (var);
8480 /* Create a new cleanup level if necessary. */
8481 maybe_push_cleanup_level (type);
8486 /* EXPR is the initializer for a variable DECL of reference or
8487 std::initializer_list type. Create, push and return a new VAR_DECL
8488 for the initializer so that it will live as long as DECL. Any
8489 cleanup for the new variable is returned through CLEANUP, and the
8490 code to initialize the new variable is returned through INITP. */
8493 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp)
8499 /* Create the temporary variable. */
8500 type = TREE_TYPE (expr);
8501 var = make_temporary_var_for_ref_to_temp (decl, type);
8502 layout_decl (var, 0);
8503 /* If the rvalue is the result of a function call it will be
8504 a TARGET_EXPR. If it is some other construct (such as a
8505 member access expression where the underlying object is
8506 itself the result of a function call), turn it into a
8507 TARGET_EXPR here. It is important that EXPR be a
8508 TARGET_EXPR below since otherwise the INIT_EXPR will
8509 attempt to make a bitwise copy of EXPR to initialize
8511 if (TREE_CODE (expr) != TARGET_EXPR)
8512 expr = get_target_expr (expr);
8514 /* If the initializer is constant, put it in DECL_INITIAL so we get
8515 static initialization and use in constant expressions. */
8516 init = maybe_constant_init (expr);
8517 if (TREE_CONSTANT (init))
8519 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
8521 /* 5.19 says that a constant expression can include an
8522 lvalue-rvalue conversion applied to "a glvalue of literal type
8523 that refers to a non-volatile temporary object initialized
8524 with a constant expression". Rather than try to communicate
8525 that this VAR_DECL is a temporary, just mark it constexpr.
8527 Currently this is only useful for initializer_list temporaries,
8528 since reference vars can't appear in constant expressions. */
8529 DECL_DECLARED_CONSTEXPR_P (var) = true;
8530 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
8531 TREE_CONSTANT (var) = true;
8533 DECL_INITIAL (var) = init;
8537 /* Create the INIT_EXPR that will initialize the temporary
8539 init = build2 (INIT_EXPR, type, var, expr);
8540 if (at_function_scope_p ())
8542 add_decl_expr (var);
8544 if (TREE_STATIC (var))
8545 init = add_stmt_to_compound (init, register_dtor_fn (var));
8547 *cleanup = cxx_maybe_build_cleanup (var, tf_warning_or_error);
8549 /* We must be careful to destroy the temporary only
8550 after its initialization has taken place. If the
8551 initialization throws an exception, then the
8552 destructor should not be run. We cannot simply
8553 transform INIT into something like:
8555 (INIT, ({ CLEANUP_STMT; }))
8557 because emit_local_var always treats the
8558 initializer as a full-expression. Thus, the
8559 destructor would run too early; it would run at the
8560 end of initializing the reference variable, rather
8561 than at the end of the block enclosing the
8564 The solution is to pass back a cleanup expression
8565 which the caller is responsible for attaching to
8566 the statement tree. */
8570 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
8571 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
8572 static_aggregates = tree_cons (NULL_TREE, var,
8580 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
8581 initializing a variable of that TYPE. If DECL is non-NULL, it is
8582 the VAR_DECL being initialized with the EXPR. (In that case, the
8583 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
8584 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
8585 return, if *CLEANUP is no longer NULL, it will be an expression
8586 that should be pushed as a cleanup after the returned expression
8587 is used to initialize DECL.
8589 Return the converted expression. */
8592 initialize_reference (tree type, tree expr, tree decl, tree *cleanup,
8593 tsubst_flags_t complain)
8598 if (type == error_mark_node || error_operand_p (expr))
8599 return error_mark_node;
8601 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8602 p = conversion_obstack_alloc (0);
8604 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
8606 if (!conv || conv->bad_p)
8608 if (complain & tf_error)
8610 if (!CP_TYPE_CONST_P (TREE_TYPE (type))
8611 && !TYPE_REF_IS_RVALUE (type)
8612 && !real_lvalue_p (expr))
8613 error ("invalid initialization of non-const reference of "
8614 "type %qT from an rvalue of type %qT",
8615 type, TREE_TYPE (expr));
8617 error ("invalid initialization of reference of type "
8618 "%qT from expression of type %qT", type,
8621 return error_mark_node;
8624 /* If DECL is non-NULL, then this special rule applies:
8628 The temporary to which the reference is bound or the temporary
8629 that is the complete object to which the reference is bound
8630 persists for the lifetime of the reference.
8632 The temporaries created during the evaluation of the expression
8633 initializing the reference, except the temporary to which the
8634 reference is bound, are destroyed at the end of the
8635 full-expression in which they are created.
8637 In that case, we store the converted expression into a new
8638 VAR_DECL in a new scope.
8640 However, we want to be careful not to create temporaries when
8641 they are not required. For example, given:
8644 struct D : public B {};
8648 there is no need to copy the return value from "f"; we can just
8649 extend its lifetime. Similarly, given:
8652 struct T { operator S(); };
8656 we can extend the lifetime of the return value of the conversion
8658 gcc_assert (conv->kind == ck_ref_bind);
8662 tree base_conv_type;
8664 gcc_assert (complain == tf_warning_or_error);
8666 /* Skip over the REF_BIND. */
8667 conv = conv->u.next;
8668 /* If the next conversion is a BASE_CONV, skip that too -- but
8669 remember that the conversion was required. */
8670 if (conv->kind == ck_base)
8672 base_conv_type = conv->type;
8673 conv = conv->u.next;
8676 base_conv_type = NULL_TREE;
8677 /* Perform the remainder of the conversion. */
8678 expr = convert_like_real (conv, expr,
8679 /*fn=*/NULL_TREE, /*argnum=*/0,
8681 /*issue_conversion_warnings=*/true,
8684 if (error_operand_p (expr))
8685 expr = error_mark_node;
8688 if (!lvalue_or_rvalue_with_address_p (expr))
8691 var = set_up_extended_ref_temp (decl, expr, cleanup, &init);
8692 /* Use its address to initialize the reference variable. */
8693 expr = build_address (var);
8695 expr = convert_to_base (expr,
8696 build_pointer_type (base_conv_type),
8697 /*check_access=*/true,
8698 /*nonnull=*/true, complain);
8700 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
8703 /* Take the address of EXPR. */
8704 expr = cp_build_addr_expr (expr, complain);
8705 /* If a BASE_CONV was required, perform it now. */
8707 expr = (perform_implicit_conversion
8708 (build_pointer_type (base_conv_type), expr,
8710 expr = build_nop (type, expr);
8711 if (DECL_DECLARED_CONSTEXPR_P (decl))
8713 expr = cxx_constant_value (expr);
8714 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)
8715 = reduced_constant_expression_p (expr);
8720 /* Perform the conversion. */
8721 expr = convert_like (conv, expr, complain);
8723 /* Free all the conversions we allocated. */
8724 obstack_free (&conversion_obstack, p);
8729 /* Returns true iff TYPE is some variant of std::initializer_list. */
8732 is_std_init_list (tree type)
8734 /* Look through typedefs. */
8737 type = TYPE_MAIN_VARIANT (type);
8738 return (CLASS_TYPE_P (type)
8739 && CP_TYPE_CONTEXT (type) == std_node
8740 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
8743 /* Returns true iff DECL is a list constructor: i.e. a constructor which
8744 will accept an argument list of a single std::initializer_list<T>. */
8747 is_list_ctor (tree decl)
8749 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
8752 if (!args || args == void_list_node)
8755 arg = non_reference (TREE_VALUE (args));
8756 if (!is_std_init_list (arg))
8759 args = TREE_CHAIN (args);
8761 if (args && args != void_list_node && !TREE_PURPOSE (args))
8762 /* There are more non-defaulted parms. */
8768 #include "gt-cp-call.h"