1 /* Functions related to invoking methods and overloaded functions.
2 Copyright (C) 1987, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
4 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com) and
6 modified by Brendan Kehoe (brendan@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
25 /* High-level class interface. */
29 #include "coretypes.h"
36 #include "diagnostic-core.h"
40 #include "langhooks.h"
41 #include "c-family/c-objc.h"
43 /* The various kinds of conversion. */
45 typedef enum conversion_kind {
61 /* The rank of the conversion. Order of the enumerals matters; better
62 conversions should come earlier in the list. */
64 typedef enum conversion_rank {
75 /* An implicit conversion sequence, in the sense of [over.best.ics].
76 The first conversion to be performed is at the end of the chain.
77 That conversion is always a cr_identity conversion. */
79 typedef struct conversion conversion;
81 /* The kind of conversion represented by this step. */
83 /* The rank of this conversion. */
85 BOOL_BITFIELD user_conv_p : 1;
86 BOOL_BITFIELD ellipsis_p : 1;
87 BOOL_BITFIELD this_p : 1;
88 /* True if this conversion would be permitted with a bending of
89 language standards, e.g. disregarding pointer qualifiers or
90 converting integers to pointers. */
91 BOOL_BITFIELD bad_p : 1;
92 /* If KIND is ck_ref_bind ck_base_conv, true to indicate that a
93 temporary should be created to hold the result of the
95 BOOL_BITFIELD need_temporary_p : 1;
96 /* If KIND is ck_ptr or ck_pmem, true to indicate that a conversion
97 from a pointer-to-derived to pointer-to-base is being performed. */
98 BOOL_BITFIELD base_p : 1;
99 /* If KIND is ck_ref_bind, true when either an lvalue reference is
100 being bound to an lvalue expression or an rvalue reference is
101 being bound to an rvalue expression. If KIND is ck_rvalue,
102 true when we should treat an lvalue as an rvalue (12.8p33). If
103 KIND is ck_base, always false. */
104 BOOL_BITFIELD rvaluedness_matches_p: 1;
105 BOOL_BITFIELD check_narrowing: 1;
106 /* The type of the expression resulting from the conversion. */
109 /* The next conversion in the chain. Since the conversions are
110 arranged from outermost to innermost, the NEXT conversion will
111 actually be performed before this conversion. This variant is
112 used only when KIND is neither ck_identity nor ck_ambig. */
114 /* The expression at the beginning of the conversion chain. This
115 variant is used only if KIND is ck_identity or ck_ambig. */
117 /* The array of conversions for an initializer_list. */
120 /* The function candidate corresponding to this conversion
121 sequence. This field is only used if KIND is ck_user. */
122 struct z_candidate *cand;
125 #define CONVERSION_RANK(NODE) \
126 ((NODE)->bad_p ? cr_bad \
127 : (NODE)->ellipsis_p ? cr_ellipsis \
128 : (NODE)->user_conv_p ? cr_user \
131 #define BAD_CONVERSION_RANK(NODE) \
132 ((NODE)->ellipsis_p ? cr_ellipsis \
133 : (NODE)->user_conv_p ? cr_user \
136 static struct obstack conversion_obstack;
137 static bool conversion_obstack_initialized;
138 struct rejection_reason;
140 static struct z_candidate * tourney (struct z_candidate *);
141 static int equal_functions (tree, tree);
142 static int joust (struct z_candidate *, struct z_candidate *, bool);
143 static int compare_ics (conversion *, conversion *);
144 static tree build_over_call (struct z_candidate *, int, tsubst_flags_t);
145 static tree build_java_interface_fn_ref (tree, tree);
146 #define convert_like(CONV, EXPR, COMPLAIN) \
147 convert_like_real ((CONV), (EXPR), NULL_TREE, 0, 0, \
148 /*issue_conversion_warnings=*/true, \
149 /*c_cast_p=*/false, (COMPLAIN))
150 #define convert_like_with_context(CONV, EXPR, FN, ARGNO, COMPLAIN ) \
151 convert_like_real ((CONV), (EXPR), (FN), (ARGNO), 0, \
152 /*issue_conversion_warnings=*/true, \
153 /*c_cast_p=*/false, (COMPLAIN))
154 static tree convert_like_real (conversion *, tree, tree, int, int, bool,
155 bool, tsubst_flags_t);
156 static void op_error (enum tree_code, enum tree_code, tree, tree,
158 static struct z_candidate *build_user_type_conversion_1 (tree, tree, int);
159 static void print_z_candidate (const char *, struct z_candidate *);
160 static void print_z_candidates (location_t, struct z_candidate *);
161 static tree build_this (tree);
162 static struct z_candidate *splice_viable (struct z_candidate *, bool, bool *);
163 static bool any_strictly_viable (struct z_candidate *);
164 static struct z_candidate *add_template_candidate
165 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
166 tree, tree, tree, int, unification_kind_t);
167 static struct z_candidate *add_template_candidate_real
168 (struct z_candidate **, tree, tree, tree, tree, const VEC(tree,gc) *,
169 tree, tree, tree, int, tree, unification_kind_t);
170 static struct z_candidate *add_template_conv_candidate
171 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
173 static void add_builtin_candidates
174 (struct z_candidate **, enum tree_code, enum tree_code,
176 static void add_builtin_candidate
177 (struct z_candidate **, enum tree_code, enum tree_code,
178 tree, tree, tree, tree *, tree *, int);
179 static bool is_complete (tree);
180 static void build_builtin_candidate
181 (struct z_candidate **, tree, tree, tree, tree *, tree *,
183 static struct z_candidate *add_conv_candidate
184 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
186 static struct z_candidate *add_function_candidate
187 (struct z_candidate **, tree, tree, tree, const VEC(tree,gc) *, tree,
189 static conversion *implicit_conversion (tree, tree, tree, bool, int);
190 static conversion *standard_conversion (tree, tree, tree, bool, int);
191 static conversion *reference_binding (tree, tree, tree, bool, int);
192 static conversion *build_conv (conversion_kind, tree, conversion *);
193 static conversion *build_list_conv (tree, tree, int);
194 static bool is_subseq (conversion *, conversion *);
195 static conversion *maybe_handle_ref_bind (conversion **);
196 static void maybe_handle_implicit_object (conversion **);
197 static struct z_candidate *add_candidate
198 (struct z_candidate **, tree, tree, const VEC(tree,gc) *, size_t,
199 conversion **, tree, tree, int, struct rejection_reason *);
200 static tree source_type (conversion *);
201 static void add_warning (struct z_candidate *, struct z_candidate *);
202 static bool reference_compatible_p (tree, tree);
203 static conversion *convert_class_to_reference (tree, tree, tree, int);
204 static conversion *direct_reference_binding (tree, conversion *);
205 static bool promoted_arithmetic_type_p (tree);
206 static conversion *conditional_conversion (tree, tree);
207 static char *name_as_c_string (tree, tree, bool *);
208 static tree prep_operand (tree);
209 static void add_candidates (tree, tree, const VEC(tree,gc) *, tree, tree, bool,
210 tree, tree, int, struct z_candidate **);
211 static conversion *merge_conversion_sequences (conversion *, conversion *);
212 static bool magic_varargs_p (tree);
213 static tree build_temp (tree, tree, int, diagnostic_t *, tsubst_flags_t);
215 /* Returns nonzero iff the destructor name specified in NAME matches BASETYPE.
216 NAME can take many forms... */
219 check_dtor_name (tree basetype, tree name)
221 /* Just accept something we've already complained about. */
222 if (name == error_mark_node)
225 if (TREE_CODE (name) == TYPE_DECL)
226 name = TREE_TYPE (name);
227 else if (TYPE_P (name))
229 else if (TREE_CODE (name) == IDENTIFIER_NODE)
231 if ((MAYBE_CLASS_TYPE_P (basetype)
232 && name == constructor_name (basetype))
233 || (TREE_CODE (basetype) == ENUMERAL_TYPE
234 && name == TYPE_IDENTIFIER (basetype)))
237 name = get_type_value (name);
243 template <class T> struct S { ~S(); };
247 NAME will be a class template. */
248 gcc_assert (DECL_CLASS_TEMPLATE_P (name));
252 if (!name || name == error_mark_node)
254 return same_type_p (TYPE_MAIN_VARIANT (basetype), TYPE_MAIN_VARIANT (name));
257 /* We want the address of a function or method. We avoid creating a
258 pointer-to-member function. */
261 build_addr_func (tree function)
263 tree type = TREE_TYPE (function);
265 /* We have to do these by hand to avoid real pointer to member
267 if (TREE_CODE (type) == METHOD_TYPE)
269 if (TREE_CODE (function) == OFFSET_REF)
271 tree object = build_address (TREE_OPERAND (function, 0));
272 return get_member_function_from_ptrfunc (&object,
273 TREE_OPERAND (function, 1));
275 function = build_address (function);
278 function = decay_conversion (function);
283 /* Build a CALL_EXPR, we can handle FUNCTION_TYPEs, METHOD_TYPEs, or
284 POINTER_TYPE to those. Note, pointer to member function types
285 (TYPE_PTRMEMFUNC_P) must be handled by our callers. There are
286 two variants. build_call_a is the primitive taking an array of
287 arguments, while build_call_n is a wrapper that handles varargs. */
290 build_call_n (tree function, int n, ...)
293 return build_call_a (function, 0, NULL);
296 tree *argarray = XALLOCAVEC (tree, n);
301 for (i = 0; i < n; i++)
302 argarray[i] = va_arg (ap, tree);
304 return build_call_a (function, n, argarray);
309 build_call_a (tree function, int n, tree *argarray)
311 int is_constructor = 0;
318 function = build_addr_func (function);
320 gcc_assert (TYPE_PTR_P (TREE_TYPE (function)));
321 fntype = TREE_TYPE (TREE_TYPE (function));
322 gcc_assert (TREE_CODE (fntype) == FUNCTION_TYPE
323 || TREE_CODE (fntype) == METHOD_TYPE);
324 result_type = TREE_TYPE (fntype);
325 /* An rvalue has no cv-qualifiers. */
326 if (SCALAR_TYPE_P (result_type) || VOID_TYPE_P (result_type))
327 result_type = cv_unqualified (result_type);
329 if (TREE_CODE (function) == ADDR_EXPR
330 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
332 decl = TREE_OPERAND (function, 0);
333 if (!TREE_USED (decl))
335 /* We invoke build_call directly for several library
336 functions. These may have been declared normally if
337 we're building libgcc, so we can't just check
339 gcc_assert (DECL_ARTIFICIAL (decl)
340 || !strncmp (IDENTIFIER_POINTER (DECL_NAME (decl)),
348 /* We check both the decl and the type; a function may be known not to
349 throw without being declared throw(). */
350 nothrow = ((decl && TREE_NOTHROW (decl))
351 || TYPE_NOTHROW_P (TREE_TYPE (TREE_TYPE (function))));
353 if (decl && TREE_THIS_VOLATILE (decl) && cfun && cp_function_chain)
354 current_function_returns_abnormally = 1;
356 if (decl && TREE_DEPRECATED (decl))
357 warn_deprecated_use (decl, NULL_TREE);
358 require_complete_eh_spec_types (fntype, decl);
360 if (decl && DECL_CONSTRUCTOR_P (decl))
363 /* Don't pass empty class objects by value. This is useful
364 for tags in STL, which are used to control overload resolution.
365 We don't need to handle other cases of copying empty classes. */
366 if (! decl || ! DECL_BUILT_IN (decl))
367 for (i = 0; i < n; i++)
368 if (is_empty_class (TREE_TYPE (argarray[i]))
369 && ! TREE_ADDRESSABLE (TREE_TYPE (argarray[i])))
371 tree t = build0 (EMPTY_CLASS_EXPR, TREE_TYPE (argarray[i]));
372 argarray[i] = build2 (COMPOUND_EXPR, TREE_TYPE (t),
376 function = build_call_array_loc (input_location,
377 result_type, function, n, argarray);
378 TREE_HAS_CONSTRUCTOR (function) = is_constructor;
379 TREE_NOTHROW (function) = nothrow;
384 /* Build something of the form ptr->method (args)
385 or object.method (args). This can also build
386 calls to constructors, and find friends.
388 Member functions always take their class variable
391 INSTANCE is a class instance.
393 NAME is the name of the method desired, usually an IDENTIFIER_NODE.
395 PARMS help to figure out what that NAME really refers to.
397 BASETYPE_PATH, if non-NULL, contains a chain from the type of INSTANCE
398 down to the real instance type to use for access checking. We need this
399 information to get protected accesses correct.
401 FLAGS is the logical disjunction of zero or more LOOKUP_
402 flags. See cp-tree.h for more info.
404 If this is all OK, calls build_function_call with the resolved
407 This function must also handle being called to perform
408 initialization, promotion/coercion of arguments, and
409 instantiation of default parameters.
411 Note that NAME may refer to an instance variable name. If
412 `operator()()' is defined for the type of that field, then we return
415 /* New overloading code. */
417 typedef struct z_candidate z_candidate;
419 typedef struct candidate_warning candidate_warning;
420 struct candidate_warning {
422 candidate_warning *next;
425 /* Information for providing diagnostics about why overloading failed. */
427 enum rejection_reason_code {
431 rr_bad_arg_conversion
434 struct conversion_info {
435 /* The index of the argument, 0-based. */
437 /* The type of the actual argument. */
439 /* The type of the formal argument. */
443 struct rejection_reason {
444 enum rejection_reason_code code;
446 /* Information about an arity mismatch. */
448 /* The expected number of arguments. */
450 /* The actual number of arguments in the call. */
452 /* Whether the call was a varargs call. */
455 /* Information about an argument conversion mismatch. */
456 struct conversion_info conversion;
457 /* Same, but for bad argument conversions. */
458 struct conversion_info bad_conversion;
463 /* The FUNCTION_DECL that will be called if this candidate is
464 selected by overload resolution. */
466 /* If not NULL_TREE, the first argument to use when calling this
469 /* The rest of the arguments to use when calling this function. If
470 there are no further arguments this may be NULL or it may be an
472 const VEC(tree,gc) *args;
473 /* The implicit conversion sequences for each of the arguments to
476 /* The number of implicit conversion sequences. */
478 /* If FN is a user-defined conversion, the standard conversion
479 sequence from the type returned by FN to the desired destination
481 conversion *second_conv;
483 struct rejection_reason *reason;
484 /* If FN is a member function, the binfo indicating the path used to
485 qualify the name of FN at the call site. This path is used to
486 determine whether or not FN is accessible if it is selected by
487 overload resolution. The DECL_CONTEXT of FN will always be a
488 (possibly improper) base of this binfo. */
490 /* If FN is a non-static member function, the binfo indicating the
491 subobject to which the `this' pointer should be converted if FN
492 is selected by overload resolution. The type pointed to the by
493 the `this' pointer must correspond to the most derived class
494 indicated by the CONVERSION_PATH. */
495 tree conversion_path;
498 candidate_warning *warnings;
502 /* Returns true iff T is a null pointer constant in the sense of
506 null_ptr_cst_p (tree t)
510 A null pointer constant is an integral constant expression
511 (_expr.const_) rvalue of integer type that evaluates to zero or
512 an rvalue of type std::nullptr_t. */
513 if (NULLPTR_TYPE_P (TREE_TYPE (t)))
515 if (CP_INTEGRAL_TYPE_P (TREE_TYPE (t)))
517 if (cxx_dialect >= cxx0x)
519 t = fold_non_dependent_expr (t);
520 t = maybe_constant_value (t);
521 if (TREE_CONSTANT (t) && integer_zerop (t))
526 t = integral_constant_value (t);
528 if (integer_zerop (t) && !TREE_OVERFLOW (t))
535 /* Returns nonzero if PARMLIST consists of only default parms and/or
539 sufficient_parms_p (const_tree parmlist)
541 for (; parmlist && parmlist != void_list_node;
542 parmlist = TREE_CHAIN (parmlist))
543 if (!TREE_PURPOSE (parmlist))
548 /* Allocate N bytes of memory from the conversion obstack. The memory
549 is zeroed before being returned. */
552 conversion_obstack_alloc (size_t n)
555 if (!conversion_obstack_initialized)
557 gcc_obstack_init (&conversion_obstack);
558 conversion_obstack_initialized = true;
560 p = obstack_alloc (&conversion_obstack, n);
565 /* Allocate rejection reasons. */
567 static struct rejection_reason *
568 alloc_rejection (enum rejection_reason_code code)
570 struct rejection_reason *p;
571 p = (struct rejection_reason *) conversion_obstack_alloc (sizeof *p);
576 static struct rejection_reason *
577 arity_rejection (tree first_arg, int expected, int actual)
579 struct rejection_reason *r = alloc_rejection (rr_arity);
580 int adjust = first_arg != NULL_TREE;
581 r->u.arity.expected = expected - adjust;
582 r->u.arity.actual = actual - adjust;
586 static struct rejection_reason *
587 arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
589 struct rejection_reason *r = alloc_rejection (rr_arg_conversion);
590 int adjust = first_arg != NULL_TREE;
591 r->u.conversion.n_arg = n_arg - adjust;
592 r->u.conversion.from_type = from;
593 r->u.conversion.to_type = to;
597 static struct rejection_reason *
598 bad_arg_conversion_rejection (tree first_arg, int n_arg, tree from, tree to)
600 struct rejection_reason *r = alloc_rejection (rr_bad_arg_conversion);
601 int adjust = first_arg != NULL_TREE;
602 r->u.bad_conversion.n_arg = n_arg - adjust;
603 r->u.bad_conversion.from_type = from;
604 r->u.bad_conversion.to_type = to;
608 /* Dynamically allocate a conversion. */
611 alloc_conversion (conversion_kind kind)
614 c = (conversion *) conversion_obstack_alloc (sizeof (conversion));
619 #ifdef ENABLE_CHECKING
621 /* Make sure that all memory on the conversion obstack has been
625 validate_conversion_obstack (void)
627 if (conversion_obstack_initialized)
628 gcc_assert ((obstack_next_free (&conversion_obstack)
629 == obstack_base (&conversion_obstack)));
632 #endif /* ENABLE_CHECKING */
634 /* Dynamically allocate an array of N conversions. */
637 alloc_conversions (size_t n)
639 return (conversion **) conversion_obstack_alloc (n * sizeof (conversion *));
643 build_conv (conversion_kind code, tree type, conversion *from)
646 conversion_rank rank = CONVERSION_RANK (from);
648 /* Note that the caller is responsible for filling in t->cand for
649 user-defined conversions. */
650 t = alloc_conversion (code);
673 t->user_conv_p = (code == ck_user || from->user_conv_p);
674 t->bad_p = from->bad_p;
679 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, a
680 specialization of std::initializer_list<T>, if such a conversion is
684 build_list_conv (tree type, tree ctor, int flags)
686 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (type), 0);
687 unsigned len = CONSTRUCTOR_NELTS (ctor);
688 conversion **subconvs = alloc_conversions (len);
693 /* Within a list-initialization we can have more user-defined
695 flags &= ~LOOKUP_NO_CONVERSION;
696 /* But no narrowing conversions. */
697 flags |= LOOKUP_NO_NARROWING;
699 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
702 = implicit_conversion (elttype, TREE_TYPE (val), val,
710 t = alloc_conversion (ck_list);
712 t->u.list = subconvs;
715 for (i = 0; i < len; ++i)
717 conversion *sub = subconvs[i];
718 if (sub->rank > t->rank)
720 if (sub->user_conv_p)
721 t->user_conv_p = true;
729 /* Subroutine of build_aggr_conv: check whether CTOR, a braced-init-list,
730 is a valid aggregate initializer for array type ATYPE. */
733 can_convert_array (tree atype, tree ctor, int flags)
736 tree elttype = TREE_TYPE (atype);
737 for (i = 0; i < CONSTRUCTOR_NELTS (ctor); ++i)
739 tree val = CONSTRUCTOR_ELT (ctor, i)->value;
741 if (TREE_CODE (elttype) == ARRAY_TYPE
742 && TREE_CODE (val) == CONSTRUCTOR)
743 ok = can_convert_array (elttype, val, flags);
745 ok = can_convert_arg (elttype, TREE_TYPE (val), val, flags);
752 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
753 aggregate class, if such a conversion is possible. */
756 build_aggr_conv (tree type, tree ctor, int flags)
758 unsigned HOST_WIDE_INT i = 0;
760 tree field = next_initializable_field (TYPE_FIELDS (type));
761 tree empty_ctor = NULL_TREE;
763 for (; field; field = next_initializable_field (DECL_CHAIN (field)))
765 tree ftype = TREE_TYPE (field);
769 if (i < CONSTRUCTOR_NELTS (ctor))
770 val = CONSTRUCTOR_ELT (ctor, i)->value;
773 if (empty_ctor == NULL_TREE)
774 empty_ctor = build_constructor (init_list_type_node, NULL);
779 if (TREE_CODE (ftype) == ARRAY_TYPE
780 && TREE_CODE (val) == CONSTRUCTOR)
781 ok = can_convert_array (ftype, val, flags);
783 ok = can_convert_arg (ftype, TREE_TYPE (val), val, flags);
788 if (TREE_CODE (type) == UNION_TYPE)
792 if (i < CONSTRUCTOR_NELTS (ctor))
795 c = alloc_conversion (ck_aggr);
798 c->user_conv_p = true;
803 /* Represent a conversion from CTOR, a braced-init-list, to TYPE, an
804 array type, if such a conversion is possible. */
807 build_array_conv (tree type, tree ctor, int flags)
810 unsigned HOST_WIDE_INT len = CONSTRUCTOR_NELTS (ctor);
811 tree elttype = TREE_TYPE (type);
816 enum conversion_rank rank = cr_exact;
818 if (TYPE_DOMAIN (type))
820 unsigned HOST_WIDE_INT alen = tree_low_cst (array_type_nelts_top (type), 1);
825 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (ctor), i, val)
828 = implicit_conversion (elttype, TREE_TYPE (val), val,
833 if (sub->rank > rank)
835 if (sub->user_conv_p)
841 c = alloc_conversion (ck_aggr);
844 c->user_conv_p = user;
850 /* Build a representation of the identity conversion from EXPR to
851 itself. The TYPE should match the type of EXPR, if EXPR is non-NULL. */
854 build_identity_conv (tree type, tree expr)
858 c = alloc_conversion (ck_identity);
865 /* Converting from EXPR to TYPE was ambiguous in the sense that there
866 were multiple user-defined conversions to accomplish the job.
867 Build a conversion that indicates that ambiguity. */
870 build_ambiguous_conv (tree type, tree expr)
874 c = alloc_conversion (ck_ambig);
882 strip_top_quals (tree t)
884 if (TREE_CODE (t) == ARRAY_TYPE)
886 return cp_build_qualified_type (t, 0);
889 /* Returns the standard conversion path (see [conv]) from type FROM to type
890 TO, if any. For proper handling of null pointer constants, you must
891 also pass the expression EXPR to convert from. If C_CAST_P is true,
892 this conversion is coming from a C-style cast. */
895 standard_conversion (tree to, tree from, tree expr, bool c_cast_p,
898 enum tree_code fcode, tcode;
900 bool fromref = false;
903 to = non_reference (to);
904 if (TREE_CODE (from) == REFERENCE_TYPE)
907 from = TREE_TYPE (from);
910 to = strip_top_quals (to);
911 from = strip_top_quals (from);
913 if ((TYPE_PTRFN_P (to) || TYPE_PTRMEMFUNC_P (to))
914 && expr && type_unknown_p (expr))
916 tsubst_flags_t tflags = tf_conv;
917 if (!(flags & LOOKUP_PROTECT))
918 tflags |= tf_no_access_control;
919 expr = instantiate_type (to, expr, tflags);
920 if (expr == error_mark_node)
922 from = TREE_TYPE (expr);
925 fcode = TREE_CODE (from);
926 tcode = TREE_CODE (to);
928 conv = build_identity_conv (from, expr);
929 if (fcode == FUNCTION_TYPE || fcode == ARRAY_TYPE)
931 from = type_decays_to (from);
932 fcode = TREE_CODE (from);
933 conv = build_conv (ck_lvalue, from, conv);
935 else if (fromref || (expr && lvalue_p (expr)))
940 bitfield_type = is_bitfield_expr_with_lowered_type (expr);
943 from = strip_top_quals (bitfield_type);
944 fcode = TREE_CODE (from);
947 conv = build_conv (ck_rvalue, from, conv);
948 if (flags & LOOKUP_PREFER_RVALUE)
949 conv->rvaluedness_matches_p = true;
952 /* Allow conversion between `__complex__' data types. */
953 if (tcode == COMPLEX_TYPE && fcode == COMPLEX_TYPE)
955 /* The standard conversion sequence to convert FROM to TO is
956 the standard conversion sequence to perform componentwise
958 conversion *part_conv = standard_conversion
959 (TREE_TYPE (to), TREE_TYPE (from), NULL_TREE, c_cast_p, flags);
963 conv = build_conv (part_conv->kind, to, conv);
964 conv->rank = part_conv->rank;
972 if (same_type_p (from, to))
974 if (CLASS_TYPE_P (to) && conv->kind == ck_rvalue)
975 conv->type = qualified_to;
980 A null pointer constant can be converted to a pointer type; ... A
981 null pointer constant of integral type can be converted to an
982 rvalue of type std::nullptr_t. */
983 if ((tcode == POINTER_TYPE || TYPE_PTR_TO_MEMBER_P (to)
984 || NULLPTR_TYPE_P (to))
985 && expr && null_ptr_cst_p (expr))
986 conv = build_conv (ck_std, to, conv);
987 else if ((tcode == INTEGER_TYPE && fcode == POINTER_TYPE)
988 || (tcode == POINTER_TYPE && fcode == INTEGER_TYPE))
990 /* For backwards brain damage compatibility, allow interconversion of
991 pointers and integers with a pedwarn. */
992 conv = build_conv (ck_std, to, conv);
995 else if (UNSCOPED_ENUM_P (to) && fcode == INTEGER_TYPE)
997 /* For backwards brain damage compatibility, allow interconversion of
998 enums and integers with a pedwarn. */
999 conv = build_conv (ck_std, to, conv);
1002 else if ((tcode == POINTER_TYPE && fcode == POINTER_TYPE)
1003 || (TYPE_PTRMEM_P (to) && TYPE_PTRMEM_P (from)))
1008 if (tcode == POINTER_TYPE
1009 && same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (from),
1012 else if (VOID_TYPE_P (TREE_TYPE (to))
1013 && !TYPE_PTRMEM_P (from)
1014 && TREE_CODE (TREE_TYPE (from)) != FUNCTION_TYPE)
1016 tree nfrom = TREE_TYPE (from);
1017 from = build_pointer_type
1018 (cp_build_qualified_type (void_type_node,
1019 cp_type_quals (nfrom)));
1020 conv = build_conv (ck_ptr, from, conv);
1022 else if (TYPE_PTRMEM_P (from))
1024 tree fbase = TYPE_PTRMEM_CLASS_TYPE (from);
1025 tree tbase = TYPE_PTRMEM_CLASS_TYPE (to);
1027 if (DERIVED_FROM_P (fbase, tbase)
1028 && (same_type_ignoring_top_level_qualifiers_p
1029 (TYPE_PTRMEM_POINTED_TO_TYPE (from),
1030 TYPE_PTRMEM_POINTED_TO_TYPE (to))))
1032 from = build_ptrmem_type (tbase,
1033 TYPE_PTRMEM_POINTED_TO_TYPE (from));
1034 conv = build_conv (ck_pmem, from, conv);
1036 else if (!same_type_p (fbase, tbase))
1039 else if (CLASS_TYPE_P (TREE_TYPE (from))
1040 && CLASS_TYPE_P (TREE_TYPE (to))
1043 An rvalue of type "pointer to cv D," where D is a
1044 class type, can be converted to an rvalue of type
1045 "pointer to cv B," where B is a base class (clause
1046 _class.derived_) of D. If B is an inaccessible
1047 (clause _class.access_) or ambiguous
1048 (_class.member.lookup_) base class of D, a program
1049 that necessitates this conversion is ill-formed.
1050 Therefore, we use DERIVED_FROM_P, and do not check
1051 access or uniqueness. */
1052 && DERIVED_FROM_P (TREE_TYPE (to), TREE_TYPE (from)))
1055 cp_build_qualified_type (TREE_TYPE (to),
1056 cp_type_quals (TREE_TYPE (from)));
1057 from = build_pointer_type (from);
1058 conv = build_conv (ck_ptr, from, conv);
1059 conv->base_p = true;
1062 if (tcode == POINTER_TYPE)
1064 to_pointee = TREE_TYPE (to);
1065 from_pointee = TREE_TYPE (from);
1069 to_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (to);
1070 from_pointee = TYPE_PTRMEM_POINTED_TO_TYPE (from);
1073 if (same_type_p (from, to))
1075 else if (c_cast_p && comp_ptr_ttypes_const (to, from))
1076 /* In a C-style cast, we ignore CV-qualification because we
1077 are allowed to perform a static_cast followed by a
1079 conv = build_conv (ck_qual, to, conv);
1080 else if (!c_cast_p && comp_ptr_ttypes (to_pointee, from_pointee))
1081 conv = build_conv (ck_qual, to, conv);
1082 else if (expr && string_conv_p (to, expr, 0))
1083 /* converting from string constant to char *. */
1084 conv = build_conv (ck_qual, to, conv);
1085 /* Allow conversions among compatible ObjC pointer types (base
1086 conversions have been already handled above). */
1087 else if (c_dialect_objc ()
1088 && objc_compare_types (to, from, -4, NULL_TREE))
1089 conv = build_conv (ck_ptr, to, conv);
1090 else if (ptr_reasonably_similar (to_pointee, from_pointee))
1092 conv = build_conv (ck_ptr, to, conv);
1100 else if (TYPE_PTRMEMFUNC_P (to) && TYPE_PTRMEMFUNC_P (from))
1102 tree fromfn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (from));
1103 tree tofn = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (to));
1104 tree fbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (fromfn)));
1105 tree tbase = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (tofn)));
1107 if (!DERIVED_FROM_P (fbase, tbase)
1108 || !same_type_p (TREE_TYPE (fromfn), TREE_TYPE (tofn))
1109 || !compparms (TREE_CHAIN (TYPE_ARG_TYPES (fromfn)),
1110 TREE_CHAIN (TYPE_ARG_TYPES (tofn)))
1111 || cp_type_quals (fbase) != cp_type_quals (tbase))
1114 from = build_memfn_type (fromfn, tbase, cp_type_quals (tbase));
1115 from = build_ptrmemfunc_type (build_pointer_type (from));
1116 conv = build_conv (ck_pmem, from, conv);
1117 conv->base_p = true;
1119 else if (tcode == BOOLEAN_TYPE)
1123 An rvalue of arithmetic, unscoped enumeration, pointer, or
1124 pointer to member type can be converted to an rvalue of type
1125 bool. ... An rvalue of type std::nullptr_t can be converted
1126 to an rvalue of type bool; */
1127 if (ARITHMETIC_TYPE_P (from)
1128 || UNSCOPED_ENUM_P (from)
1129 || fcode == POINTER_TYPE
1130 || TYPE_PTR_TO_MEMBER_P (from)
1131 || NULLPTR_TYPE_P (from))
1133 conv = build_conv (ck_std, to, conv);
1134 if (fcode == POINTER_TYPE
1135 || TYPE_PTRMEM_P (from)
1136 || (TYPE_PTRMEMFUNC_P (from)
1137 && conv->rank < cr_pbool)
1138 || NULLPTR_TYPE_P (from))
1139 conv->rank = cr_pbool;
1145 /* We don't check for ENUMERAL_TYPE here because there are no standard
1146 conversions to enum type. */
1147 /* As an extension, allow conversion to complex type. */
1148 else if (ARITHMETIC_TYPE_P (to))
1150 if (! (INTEGRAL_CODE_P (fcode) || fcode == REAL_TYPE)
1151 || SCOPED_ENUM_P (from))
1153 conv = build_conv (ck_std, to, conv);
1155 /* Give this a better rank if it's a promotion. */
1156 if (same_type_p (to, type_promotes_to (from))
1157 && conv->u.next->rank <= cr_promotion)
1158 conv->rank = cr_promotion;
1160 else if (fcode == VECTOR_TYPE && tcode == VECTOR_TYPE
1161 && vector_types_convertible_p (from, to, false))
1162 return build_conv (ck_std, to, conv);
1163 else if (MAYBE_CLASS_TYPE_P (to) && MAYBE_CLASS_TYPE_P (from)
1164 && is_properly_derived_from (from, to))
1166 if (conv->kind == ck_rvalue)
1167 conv = conv->u.next;
1168 conv = build_conv (ck_base, to, conv);
1169 /* The derived-to-base conversion indicates the initialization
1170 of a parameter with base type from an object of a derived
1171 type. A temporary object is created to hold the result of
1172 the conversion unless we're binding directly to a reference. */
1173 conv->need_temporary_p = !(flags & LOOKUP_NO_TEMP_BIND);
1178 if (flags & LOOKUP_NO_NARROWING)
1179 conv->check_narrowing = true;
1184 /* Returns nonzero if T1 is reference-related to T2. */
1187 reference_related_p (tree t1, tree t2)
1189 if (t1 == error_mark_node || t2 == error_mark_node)
1192 t1 = TYPE_MAIN_VARIANT (t1);
1193 t2 = TYPE_MAIN_VARIANT (t2);
1197 Given types "cv1 T1" and "cv2 T2," "cv1 T1" is reference-related
1198 to "cv2 T2" if T1 is the same type as T2, or T1 is a base class
1200 return (same_type_p (t1, t2)
1201 || (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
1202 && DERIVED_FROM_P (t1, t2)));
1205 /* Returns nonzero if T1 is reference-compatible with T2. */
1208 reference_compatible_p (tree t1, tree t2)
1212 "cv1 T1" is reference compatible with "cv2 T2" if T1 is
1213 reference-related to T2 and cv1 is the same cv-qualification as,
1214 or greater cv-qualification than, cv2. */
1215 return (reference_related_p (t1, t2)
1216 && at_least_as_qualified_p (t1, t2));
1219 /* Determine whether or not the EXPR (of class type S) can be
1220 converted to T as in [over.match.ref]. */
1223 convert_class_to_reference (tree reference_type, tree s, tree expr, int flags)
1229 struct z_candidate *candidates;
1230 struct z_candidate *cand;
1236 conversions = lookup_conversions (s);
1242 Assuming that "cv1 T" is the underlying type of the reference
1243 being initialized, and "cv S" is the type of the initializer
1244 expression, with S a class type, the candidate functions are
1245 selected as follows:
1247 --The conversion functions of S and its base classes are
1248 considered. Those that are not hidden within S and yield type
1249 "reference to cv2 T2", where "cv1 T" is reference-compatible
1250 (_dcl.init.ref_) with "cv2 T2", are candidate functions.
1252 The argument list has one argument, which is the initializer
1257 /* Conceptually, we should take the address of EXPR and put it in
1258 the argument list. Unfortunately, however, that can result in
1259 error messages, which we should not issue now because we are just
1260 trying to find a conversion operator. Therefore, we use NULL,
1261 cast to the appropriate type. */
1262 first_arg = build_int_cst (build_pointer_type (s), 0);
1264 t = TREE_TYPE (reference_type);
1266 /* We're performing a user-defined conversion to a desired type, so set
1267 this for the benefit of add_candidates. */
1268 flags |= LOOKUP_NO_CONVERSION;
1270 for (; conversions; conversions = TREE_CHAIN (conversions))
1272 tree fns = TREE_VALUE (conversions);
1273 tree binfo = TREE_PURPOSE (conversions);
1274 struct z_candidate *old_candidates = candidates;;
1276 add_candidates (fns, first_arg, NULL, reference_type,
1278 binfo, TYPE_BINFO (s),
1279 flags, &candidates);
1281 for (cand = candidates; cand != old_candidates; cand = cand->next)
1283 /* Now, see if the conversion function really returns
1284 an lvalue of the appropriate type. From the
1285 point of view of unification, simply returning an
1286 rvalue of the right type is good enough. */
1288 tree t2 = TREE_TYPE (TREE_TYPE (f));
1289 if (cand->viable == 0)
1290 /* Don't bother looking more closely. */;
1291 else if (TREE_CODE (t2) != REFERENCE_TYPE
1292 || !reference_compatible_p (t, TREE_TYPE (t2)))
1294 /* No need to set cand->reason here; this is most likely
1295 an ambiguous match. If it's not, either this candidate
1296 will win, or we will have identified a reason for it
1302 conversion *identity_conv;
1303 /* Build a standard conversion sequence indicating the
1304 binding from the reference type returned by the
1305 function to the desired REFERENCE_TYPE. */
1307 = build_identity_conv (TREE_TYPE (TREE_TYPE
1308 (TREE_TYPE (cand->fn))),
1311 = (direct_reference_binding
1312 (reference_type, identity_conv));
1313 cand->second_conv->rvaluedness_matches_p
1314 = TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn)))
1315 == TYPE_REF_IS_RVALUE (reference_type);
1316 cand->second_conv->bad_p |= cand->convs[0]->bad_p;
1318 /* Don't allow binding of lvalues to rvalue references. */
1319 if (TYPE_REF_IS_RVALUE (reference_type)
1320 && !TYPE_REF_IS_RVALUE (TREE_TYPE (TREE_TYPE (cand->fn))))
1321 cand->second_conv->bad_p = true;
1326 candidates = splice_viable (candidates, pedantic, &any_viable_p);
1327 /* If none of the conversion functions worked out, let our caller
1332 cand = tourney (candidates);
1336 /* Now that we know that this is the function we're going to use fix
1337 the dummy first argument. */
1338 gcc_assert (cand->first_arg == NULL_TREE
1339 || integer_zerop (cand->first_arg));
1340 cand->first_arg = build_this (expr);
1342 /* Build a user-defined conversion sequence representing the
1344 conv = build_conv (ck_user,
1345 TREE_TYPE (TREE_TYPE (cand->fn)),
1346 build_identity_conv (TREE_TYPE (expr), expr));
1349 if (cand->viable == -1)
1352 /* Merge it with the standard conversion sequence from the
1353 conversion function's return type to the desired type. */
1354 cand->second_conv = merge_conversion_sequences (conv, cand->second_conv);
1356 return cand->second_conv;
1359 /* A reference of the indicated TYPE is being bound directly to the
1360 expression represented by the implicit conversion sequence CONV.
1361 Return a conversion sequence for this binding. */
1364 direct_reference_binding (tree type, conversion *conv)
1368 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
1369 gcc_assert (TREE_CODE (conv->type) != REFERENCE_TYPE);
1371 t = TREE_TYPE (type);
1375 When a parameter of reference type binds directly
1376 (_dcl.init.ref_) to an argument expression, the implicit
1377 conversion sequence is the identity conversion, unless the
1378 argument expression has a type that is a derived class of the
1379 parameter type, in which case the implicit conversion sequence is
1380 a derived-to-base Conversion.
1382 If the parameter binds directly to the result of applying a
1383 conversion function to the argument expression, the implicit
1384 conversion sequence is a user-defined conversion sequence
1385 (_over.ics.user_), with the second standard conversion sequence
1386 either an identity conversion or, if the conversion function
1387 returns an entity of a type that is a derived class of the
1388 parameter type, a derived-to-base conversion. */
1389 if (!same_type_ignoring_top_level_qualifiers_p (t, conv->type))
1391 /* Represent the derived-to-base conversion. */
1392 conv = build_conv (ck_base, t, conv);
1393 /* We will actually be binding to the base-class subobject in
1394 the derived class, so we mark this conversion appropriately.
1395 That way, convert_like knows not to generate a temporary. */
1396 conv->need_temporary_p = false;
1398 return build_conv (ck_ref_bind, type, conv);
1401 /* Returns the conversion path from type FROM to reference type TO for
1402 purposes of reference binding. For lvalue binding, either pass a
1403 reference type to FROM or an lvalue expression to EXPR. If the
1404 reference will be bound to a temporary, NEED_TEMPORARY_P is set for
1405 the conversion returned. If C_CAST_P is true, this
1406 conversion is coming from a C-style cast. */
1409 reference_binding (tree rto, tree rfrom, tree expr, bool c_cast_p, int flags)
1411 conversion *conv = NULL;
1412 tree to = TREE_TYPE (rto);
1417 cp_lvalue_kind is_lvalue = clk_none;
1419 if (TREE_CODE (to) == FUNCTION_TYPE && expr && type_unknown_p (expr))
1421 expr = instantiate_type (to, expr, tf_none);
1422 if (expr == error_mark_node)
1424 from = TREE_TYPE (expr);
1427 if (TREE_CODE (from) == REFERENCE_TYPE)
1429 /* Anything with reference type is an lvalue. */
1430 is_lvalue = clk_ordinary;
1431 from = TREE_TYPE (from);
1434 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1436 maybe_warn_cpp0x (CPP0X_INITIALIZER_LISTS);
1437 conv = implicit_conversion (to, from, expr, c_cast_p,
1439 if (!CLASS_TYPE_P (to)
1440 && CONSTRUCTOR_NELTS (expr) == 1)
1442 expr = CONSTRUCTOR_ELT (expr, 0)->value;
1443 if (error_operand_p (expr))
1445 from = TREE_TYPE (expr);
1449 if (is_lvalue == clk_none && expr)
1450 is_lvalue = real_lvalue_p (expr);
1453 if ((is_lvalue & clk_bitfield) != 0)
1454 tfrom = unlowered_expr_type (expr);
1456 /* Figure out whether or not the types are reference-related and
1457 reference compatible. We have do do this after stripping
1458 references from FROM. */
1459 related_p = reference_related_p (to, tfrom);
1460 /* If this is a C cast, first convert to an appropriately qualified
1461 type, so that we can later do a const_cast to the desired type. */
1462 if (related_p && c_cast_p
1463 && !at_least_as_qualified_p (to, tfrom))
1464 to = cp_build_qualified_type (to, cp_type_quals (tfrom));
1465 compatible_p = reference_compatible_p (to, tfrom);
1467 /* Directly bind reference when target expression's type is compatible with
1468 the reference and expression is an lvalue. In DR391, the wording in
1469 [8.5.3/5 dcl.init.ref] is changed to also require direct bindings for
1470 const and rvalue references to rvalues of compatible class type.
1471 We should also do direct bindings for non-class "rvalues" derived from
1472 rvalue references. */
1475 || (((CP_TYPE_CONST_NON_VOLATILE_P (to)
1476 && !(flags & LOOKUP_NO_TEMP_BIND))
1477 || TYPE_REF_IS_RVALUE (rto))
1478 && (CLASS_TYPE_P (from)
1479 || TREE_CODE (from) == ARRAY_TYPE
1480 || (expr && lvalue_p (expr))))))
1484 If the initializer expression
1486 -- is an lvalue (but not an lvalue for a bit-field), and "cv1 T1"
1487 is reference-compatible with "cv2 T2,"
1489 the reference is bound directly to the initializer expression
1493 If the initializer expression is an rvalue, with T2 a class type,
1494 and "cv1 T1" is reference-compatible with "cv2 T2", the reference
1495 is bound to the object represented by the rvalue or to a sub-object
1496 within that object. */
1498 conv = build_identity_conv (tfrom, expr);
1499 conv = direct_reference_binding (rto, conv);
1501 if (flags & LOOKUP_PREFER_RVALUE)
1502 /* The top-level caller requested that we pretend that the lvalue
1503 be treated as an rvalue. */
1504 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1506 conv->rvaluedness_matches_p
1507 = (TYPE_REF_IS_RVALUE (rto) == !is_lvalue);
1509 if ((is_lvalue & clk_bitfield) != 0
1510 || ((is_lvalue & clk_packed) != 0 && !TYPE_PACKED (to)))
1511 /* For the purposes of overload resolution, we ignore the fact
1512 this expression is a bitfield or packed field. (In particular,
1513 [over.ics.ref] says specifically that a function with a
1514 non-const reference parameter is viable even if the
1515 argument is a bitfield.)
1517 However, when we actually call the function we must create
1518 a temporary to which to bind the reference. If the
1519 reference is volatile, or isn't const, then we cannot make
1520 a temporary, so we just issue an error when the conversion
1522 conv->need_temporary_p = true;
1524 /* Don't allow binding of lvalues (other than function lvalues) to
1525 rvalue references. */
1526 if (is_lvalue && TYPE_REF_IS_RVALUE (rto)
1527 && TREE_CODE (to) != FUNCTION_TYPE
1528 && !(flags & LOOKUP_PREFER_RVALUE))
1533 /* [class.conv.fct] A conversion function is never used to convert a
1534 (possibly cv-qualified) object to the (possibly cv-qualified) same
1535 object type (or a reference to it), to a (possibly cv-qualified) base
1536 class of that type (or a reference to it).... */
1537 else if (CLASS_TYPE_P (from) && !related_p
1538 && !(flags & LOOKUP_NO_CONVERSION))
1542 If the initializer expression
1544 -- has a class type (i.e., T2 is a class type) can be
1545 implicitly converted to an lvalue of type "cv3 T3," where
1546 "cv1 T1" is reference-compatible with "cv3 T3". (this
1547 conversion is selected by enumerating the applicable
1548 conversion functions (_over.match.ref_) and choosing the
1549 best one through overload resolution. (_over.match_).
1551 the reference is bound to the lvalue result of the conversion
1552 in the second case. */
1553 conv = convert_class_to_reference (rto, from, expr, flags);
1558 /* From this point on, we conceptually need temporaries, even if we
1559 elide them. Only the cases above are "direct bindings". */
1560 if (flags & LOOKUP_NO_TEMP_BIND)
1565 When a parameter of reference type is not bound directly to an
1566 argument expression, the conversion sequence is the one required
1567 to convert the argument expression to the underlying type of the
1568 reference according to _over.best.ics_. Conceptually, this
1569 conversion sequence corresponds to copy-initializing a temporary
1570 of the underlying type with the argument expression. Any
1571 difference in top-level cv-qualification is subsumed by the
1572 initialization itself and does not constitute a conversion. */
1576 Otherwise, the reference shall be to a non-volatile const type.
1578 Under C++0x, [8.5.3/5 dcl.init.ref] it may also be an rvalue reference */
1579 if (!CP_TYPE_CONST_NON_VOLATILE_P (to) && !TYPE_REF_IS_RVALUE (rto))
1584 Otherwise, a temporary of type "cv1 T1" is created and
1585 initialized from the initializer expression using the rules for a
1586 non-reference copy initialization. If T1 is reference-related to
1587 T2, cv1 must be the same cv-qualification as, or greater
1588 cv-qualification than, cv2; otherwise, the program is ill-formed. */
1589 if (related_p && !at_least_as_qualified_p (to, from))
1592 /* We're generating a temporary now, but don't bind any more in the
1593 conversion (specifically, don't slice the temporary returned by a
1594 conversion operator). */
1595 flags |= LOOKUP_NO_TEMP_BIND;
1597 /* Core issue 899: When [copy-]initializing a temporary to be bound
1598 to the first parameter of a copy constructor (12.8) called with
1599 a single argument in the context of direct-initialization,
1600 explicit conversion functions are also considered.
1602 So don't set LOOKUP_ONLYCONVERTING in that case. */
1603 if (!(flags & LOOKUP_COPY_PARM))
1604 flags |= LOOKUP_ONLYCONVERTING;
1607 conv = implicit_conversion (to, from, expr, c_cast_p,
1612 conv = build_conv (ck_ref_bind, rto, conv);
1613 /* This reference binding, unlike those above, requires the
1614 creation of a temporary. */
1615 conv->need_temporary_p = true;
1616 conv->rvaluedness_matches_p = TYPE_REF_IS_RVALUE (rto);
1621 /* Returns the implicit conversion sequence (see [over.ics]) from type
1622 FROM to type TO. The optional expression EXPR may affect the
1623 conversion. FLAGS are the usual overloading flags. If C_CAST_P is
1624 true, this conversion is coming from a C-style cast. */
1627 implicit_conversion (tree to, tree from, tree expr, bool c_cast_p,
1632 if (from == error_mark_node || to == error_mark_node
1633 || expr == error_mark_node)
1636 if (TREE_CODE (to) == REFERENCE_TYPE)
1637 conv = reference_binding (to, from, expr, c_cast_p, flags);
1639 conv = standard_conversion (to, from, expr, c_cast_p, flags);
1644 if (expr && BRACE_ENCLOSED_INITIALIZER_P (expr))
1646 if (is_std_init_list (to))
1647 return build_list_conv (to, expr, flags);
1649 /* Allow conversion from an initializer-list with one element to a
1651 if (SCALAR_TYPE_P (to))
1653 int nelts = CONSTRUCTOR_NELTS (expr);
1657 elt = build_value_init (to, tf_none);
1658 else if (nelts == 1)
1659 elt = CONSTRUCTOR_ELT (expr, 0)->value;
1661 elt = error_mark_node;
1663 conv = implicit_conversion (to, TREE_TYPE (elt), elt,
1667 conv->check_narrowing = true;
1668 if (BRACE_ENCLOSED_INITIALIZER_P (elt))
1669 /* Too many levels of braces, i.e. '{{1}}'. */
1674 else if (TREE_CODE (to) == ARRAY_TYPE)
1675 return build_array_conv (to, expr, flags);
1678 if (expr != NULL_TREE
1679 && (MAYBE_CLASS_TYPE_P (from)
1680 || MAYBE_CLASS_TYPE_P (to))
1681 && (flags & LOOKUP_NO_CONVERSION) == 0)
1683 struct z_candidate *cand;
1684 int convflags = (flags & (LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING
1685 |LOOKUP_NO_NARROWING));
1687 if (CLASS_TYPE_P (to)
1688 && !CLASSTYPE_NON_AGGREGATE (complete_type (to))
1689 && BRACE_ENCLOSED_INITIALIZER_P (expr))
1690 return build_aggr_conv (to, expr, flags);
1692 cand = build_user_type_conversion_1 (to, expr, convflags);
1694 conv = cand->second_conv;
1696 /* We used to try to bind a reference to a temporary here, but that
1697 is now handled after the recursive call to this function at the end
1698 of reference_binding. */
1705 /* Add a new entry to the list of candidates. Used by the add_*_candidate
1706 functions. ARGS will not be changed until a single candidate is
1709 static struct z_candidate *
1710 add_candidate (struct z_candidate **candidates,
1711 tree fn, tree first_arg, const VEC(tree,gc) *args,
1712 size_t num_convs, conversion **convs,
1713 tree access_path, tree conversion_path,
1714 int viable, struct rejection_reason *reason)
1716 struct z_candidate *cand = (struct z_candidate *)
1717 conversion_obstack_alloc (sizeof (struct z_candidate));
1720 cand->first_arg = first_arg;
1722 cand->convs = convs;
1723 cand->num_convs = num_convs;
1724 cand->access_path = access_path;
1725 cand->conversion_path = conversion_path;
1726 cand->viable = viable;
1727 cand->reason = reason;
1728 cand->next = *candidates;
1734 /* Return the number of remaining arguments in the parameter list
1735 beginning with ARG. */
1738 remaining_arguments (tree arg)
1742 for (n = 0; arg != NULL_TREE && arg != void_list_node;
1743 arg = TREE_CHAIN (arg))
1749 /* Create an overload candidate for the function or method FN called
1750 with the argument list FIRST_ARG/ARGS and add it to CANDIDATES.
1751 FLAGS is passed on to implicit_conversion.
1753 This does not change ARGS.
1755 CTYPE, if non-NULL, is the type we want to pretend this function
1756 comes from for purposes of overload resolution. */
1758 static struct z_candidate *
1759 add_function_candidate (struct z_candidate **candidates,
1760 tree fn, tree ctype, tree first_arg,
1761 const VEC(tree,gc) *args, tree access_path,
1762 tree conversion_path, int flags)
1764 tree parmlist = TYPE_ARG_TYPES (TREE_TYPE (fn));
1768 tree orig_first_arg = first_arg;
1771 struct rejection_reason *reason = NULL;
1773 /* At this point we should not see any functions which haven't been
1774 explicitly declared, except for friend functions which will have
1775 been found using argument dependent lookup. */
1776 gcc_assert (!DECL_ANTICIPATED (fn) || DECL_HIDDEN_FRIEND_P (fn));
1778 /* The `this', `in_chrg' and VTT arguments to constructors are not
1779 considered in overload resolution. */
1780 if (DECL_CONSTRUCTOR_P (fn))
1782 parmlist = skip_artificial_parms_for (fn, parmlist);
1783 skip = num_artificial_parms_for (fn);
1784 if (skip > 0 && first_arg != NULL_TREE)
1787 first_arg = NULL_TREE;
1793 len = VEC_length (tree, args) - skip + (first_arg != NULL_TREE ? 1 : 0);
1794 convs = alloc_conversions (len);
1796 /* 13.3.2 - Viable functions [over.match.viable]
1797 First, to be a viable function, a candidate function shall have enough
1798 parameters to agree in number with the arguments in the list.
1800 We need to check this first; otherwise, checking the ICSes might cause
1801 us to produce an ill-formed template instantiation. */
1803 parmnode = parmlist;
1804 for (i = 0; i < len; ++i)
1806 if (parmnode == NULL_TREE || parmnode == void_list_node)
1808 parmnode = TREE_CHAIN (parmnode);
1811 if ((i < len && parmnode)
1812 || !sufficient_parms_p (parmnode))
1814 int remaining = remaining_arguments (parmnode);
1816 reason = arity_rejection (first_arg, i + remaining, len);
1818 /* When looking for a function from a subobject from an implicit
1819 copy/move constructor/operator=, don't consider anything that takes (a
1820 reference to) an unrelated type. See c++/44909 and core 1092. */
1821 else if (parmlist && (flags & LOOKUP_DEFAULTED))
1823 if (DECL_CONSTRUCTOR_P (fn))
1825 else if (DECL_ASSIGNMENT_OPERATOR_P (fn)
1826 && DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR)
1832 parmnode = chain_index (i-1, parmlist);
1833 if (!reference_related_p (non_reference (TREE_VALUE (parmnode)),
1838 /* This only applies at the top level. */
1839 flags &= ~LOOKUP_DEFAULTED;
1845 /* Second, for F to be a viable function, there shall exist for each
1846 argument an implicit conversion sequence that converts that argument
1847 to the corresponding parameter of F. */
1849 parmnode = parmlist;
1851 for (i = 0; i < len; ++i)
1853 tree arg, argtype, to_type;
1857 if (parmnode == void_list_node)
1860 if (i == 0 && first_arg != NULL_TREE)
1863 arg = VEC_index (tree, args,
1864 i + skip - (first_arg != NULL_TREE ? 1 : 0));
1865 argtype = lvalue_type (arg);
1867 is_this = (i == 0 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1868 && ! DECL_CONSTRUCTOR_P (fn));
1872 tree parmtype = TREE_VALUE (parmnode);
1875 parmnode = TREE_CHAIN (parmnode);
1877 /* The type of the implicit object parameter ('this') for
1878 overload resolution is not always the same as for the
1879 function itself; conversion functions are considered to
1880 be members of the class being converted, and functions
1881 introduced by a using-declaration are considered to be
1882 members of the class that uses them.
1884 Since build_over_call ignores the ICS for the `this'
1885 parameter, we can just change the parm type. */
1886 if (ctype && is_this)
1888 parmtype = cp_build_qualified_type
1889 (ctype, cp_type_quals (TREE_TYPE (parmtype)));
1890 parmtype = build_pointer_type (parmtype);
1893 /* Core issue 899: When [copy-]initializing a temporary to be bound
1894 to the first parameter of a copy constructor (12.8) called with
1895 a single argument in the context of direct-initialization,
1896 explicit conversion functions are also considered.
1898 So set LOOKUP_COPY_PARM to let reference_binding know that
1899 it's being called in that context. We generalize the above
1900 to handle move constructors and template constructors as well;
1901 the standardese should soon be updated similarly. */
1902 if (ctype && i == 0 && (len-skip == 1)
1903 && !(flags & LOOKUP_ONLYCONVERTING)
1904 && DECL_CONSTRUCTOR_P (fn)
1905 && parmtype != error_mark_node
1906 && (same_type_ignoring_top_level_qualifiers_p
1907 (non_reference (parmtype), ctype)))
1909 lflags |= LOOKUP_COPY_PARM;
1910 /* We allow user-defined conversions within init-lists, but
1911 not for the copy constructor. */
1912 if (flags & LOOKUP_NO_COPY_CTOR_CONVERSION)
1913 lflags |= LOOKUP_NO_CONVERSION;
1916 lflags |= LOOKUP_ONLYCONVERTING;
1918 t = implicit_conversion (parmtype, argtype, arg,
1919 /*c_cast_p=*/false, lflags);
1924 t = build_identity_conv (argtype, arg);
1925 t->ellipsis_p = true;
1936 reason = arg_conversion_rejection (first_arg, i, argtype, to_type);
1943 reason = bad_arg_conversion_rejection (first_arg, i, argtype, to_type);
1948 return add_candidate (candidates, fn, orig_first_arg, args, len, convs,
1949 access_path, conversion_path, viable, reason);
1952 /* Create an overload candidate for the conversion function FN which will
1953 be invoked for expression OBJ, producing a pointer-to-function which
1954 will in turn be called with the argument list FIRST_ARG/ARGLIST,
1955 and add it to CANDIDATES. This does not change ARGLIST. FLAGS is
1956 passed on to implicit_conversion.
1958 Actually, we don't really care about FN; we care about the type it
1959 converts to. There may be multiple conversion functions that will
1960 convert to that type, and we rely on build_user_type_conversion_1 to
1961 choose the best one; so when we create our candidate, we record the type
1962 instead of the function. */
1964 static struct z_candidate *
1965 add_conv_candidate (struct z_candidate **candidates, tree fn, tree obj,
1966 tree first_arg, const VEC(tree,gc) *arglist,
1967 tree access_path, tree conversion_path)
1969 tree totype = TREE_TYPE (TREE_TYPE (fn));
1970 int i, len, viable, flags;
1971 tree parmlist, parmnode;
1973 struct rejection_reason *reason;
1975 for (parmlist = totype; TREE_CODE (parmlist) != FUNCTION_TYPE; )
1976 parmlist = TREE_TYPE (parmlist);
1977 parmlist = TYPE_ARG_TYPES (parmlist);
1979 len = VEC_length (tree, arglist) + (first_arg != NULL_TREE ? 1 : 0) + 1;
1980 convs = alloc_conversions (len);
1981 parmnode = parmlist;
1983 flags = LOOKUP_IMPLICIT;
1986 /* Don't bother looking up the same type twice. */
1987 if (*candidates && (*candidates)->fn == totype)
1990 for (i = 0; i < len; ++i)
1992 tree arg, argtype, convert_type = NULL_TREE;
1997 else if (i == 1 && first_arg != NULL_TREE)
2000 arg = VEC_index (tree, arglist,
2001 i - (first_arg != NULL_TREE ? 1 : 0) - 1);
2002 argtype = lvalue_type (arg);
2006 t = implicit_conversion (totype, argtype, arg, /*c_cast_p=*/false,
2008 convert_type = totype;
2010 else if (parmnode == void_list_node)
2014 t = implicit_conversion (TREE_VALUE (parmnode), argtype, arg,
2015 /*c_cast_p=*/false, flags);
2016 convert_type = TREE_VALUE (parmnode);
2020 t = build_identity_conv (argtype, arg);
2021 t->ellipsis_p = true;
2022 convert_type = argtype;
2032 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtype, convert_type);
2039 parmnode = TREE_CHAIN (parmnode);
2043 || ! sufficient_parms_p (parmnode))
2045 int remaining = remaining_arguments (parmnode);
2047 reason = arity_rejection (NULL_TREE, i + remaining, len);
2050 return add_candidate (candidates, totype, first_arg, arglist, len, convs,
2051 access_path, conversion_path, viable, reason);
2055 build_builtin_candidate (struct z_candidate **candidates, tree fnname,
2056 tree type1, tree type2, tree *args, tree *argtypes,
2064 struct rejection_reason *reason = NULL;
2069 num_convs = args[2] ? 3 : (args[1] ? 2 : 1);
2070 convs = alloc_conversions (num_convs);
2072 /* TRUTH_*_EXPR do "contextual conversion to bool", which means explicit
2073 conversion ops are allowed. We handle that here by just checking for
2074 boolean_type_node because other operators don't ask for it. COND_EXPR
2075 also does contextual conversion to bool for the first operand, but we
2076 handle that in build_conditional_expr, and type1 here is operand 2. */
2077 if (type1 != boolean_type_node)
2078 flags |= LOOKUP_ONLYCONVERTING;
2080 for (i = 0; i < 2; ++i)
2085 t = implicit_conversion (types[i], argtypes[i], args[i],
2086 /*c_cast_p=*/false, flags);
2090 /* We need something for printing the candidate. */
2091 t = build_identity_conv (types[i], NULL_TREE);
2092 reason = arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2097 reason = bad_arg_conversion_rejection (NULL_TREE, i, argtypes[i], types[i]);
2102 /* For COND_EXPR we rearranged the arguments; undo that now. */
2105 convs[2] = convs[1];
2106 convs[1] = convs[0];
2107 t = implicit_conversion (boolean_type_node, argtypes[2], args[2],
2108 /*c_cast_p=*/false, flags);
2114 reason = arg_conversion_rejection (NULL_TREE, 0, argtypes[2],
2119 add_candidate (candidates, fnname, /*first_arg=*/NULL_TREE, /*args=*/NULL,
2121 /*access_path=*/NULL_TREE,
2122 /*conversion_path=*/NULL_TREE,
2127 is_complete (tree t)
2129 return COMPLETE_TYPE_P (complete_type (t));
2132 /* Returns nonzero if TYPE is a promoted arithmetic type. */
2135 promoted_arithmetic_type_p (tree type)
2139 In this section, the term promoted integral type is used to refer
2140 to those integral types which are preserved by integral promotion
2141 (including e.g. int and long but excluding e.g. char).
2142 Similarly, the term promoted arithmetic type refers to promoted
2143 integral types plus floating types. */
2144 return ((CP_INTEGRAL_TYPE_P (type)
2145 && same_type_p (type_promotes_to (type), type))
2146 || TREE_CODE (type) == REAL_TYPE);
2149 /* Create any builtin operator overload candidates for the operator in
2150 question given the converted operand types TYPE1 and TYPE2. The other
2151 args are passed through from add_builtin_candidates to
2152 build_builtin_candidate.
2154 TYPE1 and TYPE2 may not be permissible, and we must filter them.
2155 If CODE is requires candidates operands of the same type of the kind
2156 of which TYPE1 and TYPE2 are, we add both candidates
2157 CODE (TYPE1, TYPE1) and CODE (TYPE2, TYPE2). */
2160 add_builtin_candidate (struct z_candidate **candidates, enum tree_code code,
2161 enum tree_code code2, tree fnname, tree type1,
2162 tree type2, tree *args, tree *argtypes, int flags)
2166 case POSTINCREMENT_EXPR:
2167 case POSTDECREMENT_EXPR:
2168 args[1] = integer_zero_node;
2169 type2 = integer_type_node;
2178 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2179 and VQ is either volatile or empty, there exist candidate operator
2180 functions of the form
2181 VQ T& operator++(VQ T&);
2182 T operator++(VQ T&, int);
2183 5 For every pair T, VQ), where T is an enumeration type or an arithmetic
2184 type other than bool, and VQ is either volatile or empty, there exist
2185 candidate operator functions of the form
2186 VQ T& operator--(VQ T&);
2187 T operator--(VQ T&, int);
2188 6 For every pair T, VQ), where T is a cv-qualified or cv-unqualified
2189 complete object type, and VQ is either volatile or empty, there exist
2190 candidate operator functions of the form
2191 T*VQ& operator++(T*VQ&);
2192 T*VQ& operator--(T*VQ&);
2193 T* operator++(T*VQ&, int);
2194 T* operator--(T*VQ&, int); */
2196 case POSTDECREMENT_EXPR:
2197 case PREDECREMENT_EXPR:
2198 if (TREE_CODE (type1) == BOOLEAN_TYPE)
2200 case POSTINCREMENT_EXPR:
2201 case PREINCREMENT_EXPR:
2202 if (ARITHMETIC_TYPE_P (type1) || TYPE_PTROB_P (type1))
2204 type1 = build_reference_type (type1);
2209 /* 7 For every cv-qualified or cv-unqualified object type T, there
2210 exist candidate operator functions of the form
2214 8 For every function type T, there exist candidate operator functions of
2216 T& operator*(T*); */
2219 if (TREE_CODE (type1) == POINTER_TYPE
2220 && !uses_template_parms (TREE_TYPE (type1))
2221 && (TYPE_PTROB_P (type1)
2222 || TREE_CODE (TREE_TYPE (type1)) == FUNCTION_TYPE))
2226 /* 9 For every type T, there exist candidate operator functions of the form
2229 10For every promoted arithmetic type T, there exist candidate operator
2230 functions of the form
2234 case UNARY_PLUS_EXPR: /* unary + */
2235 if (TREE_CODE (type1) == POINTER_TYPE)
2238 if (ARITHMETIC_TYPE_P (type1))
2242 /* 11For every promoted integral type T, there exist candidate operator
2243 functions of the form
2247 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1))
2251 /* 12For every quintuple C1, C2, T, CV1, CV2), where C2 is a class type, C1
2252 is the same type as C2 or is a derived class of C2, T is a complete
2253 object type or a function type, and CV1 and CV2 are cv-qualifier-seqs,
2254 there exist candidate operator functions of the form
2255 CV12 T& operator->*(CV1 C1*, CV2 T C2::*);
2256 where CV12 is the union of CV1 and CV2. */
2259 if (TREE_CODE (type1) == POINTER_TYPE
2260 && TYPE_PTR_TO_MEMBER_P (type2))
2262 tree c1 = TREE_TYPE (type1);
2263 tree c2 = TYPE_PTRMEM_CLASS_TYPE (type2);
2265 if (MAYBE_CLASS_TYPE_P (c1) && DERIVED_FROM_P (c2, c1)
2266 && (TYPE_PTRMEMFUNC_P (type2)
2267 || is_complete (TYPE_PTRMEM_POINTED_TO_TYPE (type2))))
2272 /* 13For every pair of promoted arithmetic types L and R, there exist can-
2273 didate operator functions of the form
2278 bool operator<(L, R);
2279 bool operator>(L, R);
2280 bool operator<=(L, R);
2281 bool operator>=(L, R);
2282 bool operator==(L, R);
2283 bool operator!=(L, R);
2284 where LR is the result of the usual arithmetic conversions between
2287 14For every pair of types T and I, where T is a cv-qualified or cv-
2288 unqualified complete object type and I is a promoted integral type,
2289 there exist candidate operator functions of the form
2290 T* operator+(T*, I);
2291 T& operator[](T*, I);
2292 T* operator-(T*, I);
2293 T* operator+(I, T*);
2294 T& operator[](I, T*);
2296 15For every T, where T is a pointer to complete object type, there exist
2297 candidate operator functions of the form112)
2298 ptrdiff_t operator-(T, T);
2300 16For every pointer or enumeration type T, there exist candidate operator
2301 functions of the form
2302 bool operator<(T, T);
2303 bool operator>(T, T);
2304 bool operator<=(T, T);
2305 bool operator>=(T, T);
2306 bool operator==(T, T);
2307 bool operator!=(T, T);
2309 17For every pointer to member type T, there exist candidate operator
2310 functions of the form
2311 bool operator==(T, T);
2312 bool operator!=(T, T); */
2315 if (TYPE_PTROB_P (type1) && TYPE_PTROB_P (type2))
2317 if (TYPE_PTROB_P (type1)
2318 && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2320 type2 = ptrdiff_type_node;
2324 case TRUNC_DIV_EXPR:
2325 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2331 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2332 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2)))
2334 if (TYPE_PTR_TO_MEMBER_P (type1) && null_ptr_cst_p (args[1]))
2339 if (TYPE_PTR_TO_MEMBER_P (type2) && null_ptr_cst_p (args[0]))
2351 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2353 if (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2355 if (TREE_CODE (type1) == ENUMERAL_TYPE
2356 && TREE_CODE (type2) == ENUMERAL_TYPE)
2358 if (TYPE_PTR_P (type1)
2359 && null_ptr_cst_p (args[1])
2360 && !uses_template_parms (type1))
2365 if (null_ptr_cst_p (args[0])
2366 && TYPE_PTR_P (type2)
2367 && !uses_template_parms (type2))
2375 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2378 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && TYPE_PTROB_P (type2))
2380 type1 = ptrdiff_type_node;
2383 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2385 type2 = ptrdiff_type_node;
2390 /* 18For every pair of promoted integral types L and R, there exist candi-
2391 date operator functions of the form
2398 where LR is the result of the usual arithmetic conversions between
2401 case TRUNC_MOD_EXPR:
2407 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2411 /* 19For every triple L, VQ, R), where L is an arithmetic or enumeration
2412 type, VQ is either volatile or empty, and R is a promoted arithmetic
2413 type, there exist candidate operator functions of the form
2414 VQ L& operator=(VQ L&, R);
2415 VQ L& operator*=(VQ L&, R);
2416 VQ L& operator/=(VQ L&, R);
2417 VQ L& operator+=(VQ L&, R);
2418 VQ L& operator-=(VQ L&, R);
2420 20For every pair T, VQ), where T is any type and VQ is either volatile
2421 or empty, there exist candidate operator functions of the form
2422 T*VQ& operator=(T*VQ&, T*);
2424 21For every pair T, VQ), where T is a pointer to member type and VQ is
2425 either volatile or empty, there exist candidate operator functions of
2427 VQ T& operator=(VQ T&, T);
2429 22For every triple T, VQ, I), where T is a cv-qualified or cv-
2430 unqualified complete object type, VQ is either volatile or empty, and
2431 I is a promoted integral type, there exist candidate operator func-
2433 T*VQ& operator+=(T*VQ&, I);
2434 T*VQ& operator-=(T*VQ&, I);
2436 23For every triple L, VQ, R), where L is an integral or enumeration
2437 type, VQ is either volatile or empty, and R is a promoted integral
2438 type, there exist candidate operator functions of the form
2440 VQ L& operator%=(VQ L&, R);
2441 VQ L& operator<<=(VQ L&, R);
2442 VQ L& operator>>=(VQ L&, R);
2443 VQ L& operator&=(VQ L&, R);
2444 VQ L& operator^=(VQ L&, R);
2445 VQ L& operator|=(VQ L&, R); */
2452 if (TYPE_PTROB_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2454 type2 = ptrdiff_type_node;
2458 case TRUNC_DIV_EXPR:
2459 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2463 case TRUNC_MOD_EXPR:
2469 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type1) && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type2))
2474 if (ARITHMETIC_TYPE_P (type1) && ARITHMETIC_TYPE_P (type2))
2476 if ((TYPE_PTRMEMFUNC_P (type1) && TYPE_PTRMEMFUNC_P (type2))
2477 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2478 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2479 || ((TYPE_PTRMEMFUNC_P (type1)
2480 || TREE_CODE (type1) == POINTER_TYPE)
2481 && null_ptr_cst_p (args[1])))
2491 type1 = build_reference_type (type1);
2497 For every pair of promoted arithmetic types L and R, there
2498 exist candidate operator functions of the form
2500 LR operator?(bool, L, R);
2502 where LR is the result of the usual arithmetic conversions
2503 between types L and R.
2505 For every type T, where T is a pointer or pointer-to-member
2506 type, there exist candidate operator functions of the form T
2507 operator?(bool, T, T); */
2509 if (promoted_arithmetic_type_p (type1)
2510 && promoted_arithmetic_type_p (type2))
2514 /* Otherwise, the types should be pointers. */
2515 if (!(TYPE_PTR_P (type1) || TYPE_PTR_TO_MEMBER_P (type1))
2516 || !(TYPE_PTR_P (type2) || TYPE_PTR_TO_MEMBER_P (type2)))
2519 /* We don't check that the two types are the same; the logic
2520 below will actually create two candidates; one in which both
2521 parameter types are TYPE1, and one in which both parameter
2529 /* If we're dealing with two pointer types or two enumeral types,
2530 we need candidates for both of them. */
2531 if (type2 && !same_type_p (type1, type2)
2532 && TREE_CODE (type1) == TREE_CODE (type2)
2533 && (TREE_CODE (type1) == REFERENCE_TYPE
2534 || (TYPE_PTR_P (type1) && TYPE_PTR_P (type2))
2535 || (TYPE_PTRMEM_P (type1) && TYPE_PTRMEM_P (type2))
2536 || TYPE_PTRMEMFUNC_P (type1)
2537 || MAYBE_CLASS_TYPE_P (type1)
2538 || TREE_CODE (type1) == ENUMERAL_TYPE))
2540 build_builtin_candidate
2541 (candidates, fnname, type1, type1, args, argtypes, flags);
2542 build_builtin_candidate
2543 (candidates, fnname, type2, type2, args, argtypes, flags);
2547 build_builtin_candidate
2548 (candidates, fnname, type1, type2, args, argtypes, flags);
2552 type_decays_to (tree type)
2554 if (TREE_CODE (type) == ARRAY_TYPE)
2555 return build_pointer_type (TREE_TYPE (type));
2556 if (TREE_CODE (type) == FUNCTION_TYPE)
2557 return build_pointer_type (type);
2558 if (!MAYBE_CLASS_TYPE_P (type))
2559 type = cv_unqualified (type);
2563 /* There are three conditions of builtin candidates:
2565 1) bool-taking candidates. These are the same regardless of the input.
2566 2) pointer-pair taking candidates. These are generated for each type
2567 one of the input types converts to.
2568 3) arithmetic candidates. According to the standard, we should generate
2569 all of these, but I'm trying not to...
2571 Here we generate a superset of the possible candidates for this particular
2572 case. That is a subset of the full set the standard defines, plus some
2573 other cases which the standard disallows. add_builtin_candidate will
2574 filter out the invalid set. */
2577 add_builtin_candidates (struct z_candidate **candidates, enum tree_code code,
2578 enum tree_code code2, tree fnname, tree *args,
2583 tree type, argtypes[3], t;
2584 /* TYPES[i] is the set of possible builtin-operator parameter types
2585 we will consider for the Ith argument. */
2586 VEC(tree,gc) *types[2];
2589 for (i = 0; i < 3; ++i)
2592 argtypes[i] = unlowered_expr_type (args[i]);
2594 argtypes[i] = NULL_TREE;
2599 /* 4 For every pair T, VQ), where T is an arithmetic or enumeration type,
2600 and VQ is either volatile or empty, there exist candidate operator
2601 functions of the form
2602 VQ T& operator++(VQ T&); */
2604 case POSTINCREMENT_EXPR:
2605 case PREINCREMENT_EXPR:
2606 case POSTDECREMENT_EXPR:
2607 case PREDECREMENT_EXPR:
2612 /* 24There also exist candidate operator functions of the form
2613 bool operator!(bool);
2614 bool operator&&(bool, bool);
2615 bool operator||(bool, bool); */
2617 case TRUTH_NOT_EXPR:
2618 build_builtin_candidate
2619 (candidates, fnname, boolean_type_node,
2620 NULL_TREE, args, argtypes, flags);
2623 case TRUTH_ORIF_EXPR:
2624 case TRUTH_ANDIF_EXPR:
2625 build_builtin_candidate
2626 (candidates, fnname, boolean_type_node,
2627 boolean_type_node, args, argtypes, flags);
2649 types[0] = make_tree_vector ();
2650 types[1] = make_tree_vector ();
2652 for (i = 0; i < 2; ++i)
2656 else if (MAYBE_CLASS_TYPE_P (argtypes[i]))
2660 if (i == 0 && code == MODIFY_EXPR && code2 == NOP_EXPR)
2663 convs = lookup_conversions (argtypes[i]);
2665 if (code == COND_EXPR)
2667 if (real_lvalue_p (args[i]))
2668 VEC_safe_push (tree, gc, types[i],
2669 build_reference_type (argtypes[i]));
2671 VEC_safe_push (tree, gc, types[i],
2672 TYPE_MAIN_VARIANT (argtypes[i]));
2678 for (; convs; convs = TREE_CHAIN (convs))
2680 type = TREE_TYPE (convs);
2683 && (TREE_CODE (type) != REFERENCE_TYPE
2684 || CP_TYPE_CONST_P (TREE_TYPE (type))))
2687 if (code == COND_EXPR && TREE_CODE (type) == REFERENCE_TYPE)
2688 VEC_safe_push (tree, gc, types[i], type);
2690 type = non_reference (type);
2691 if (i != 0 || ! ref1)
2693 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2694 if (enum_p && TREE_CODE (type) == ENUMERAL_TYPE)
2695 VEC_safe_push (tree, gc, types[i], type);
2696 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2697 type = type_promotes_to (type);
2700 if (! vec_member (type, types[i]))
2701 VEC_safe_push (tree, gc, types[i], type);
2706 if (code == COND_EXPR && real_lvalue_p (args[i]))
2707 VEC_safe_push (tree, gc, types[i],
2708 build_reference_type (argtypes[i]));
2709 type = non_reference (argtypes[i]);
2710 if (i != 0 || ! ref1)
2712 type = TYPE_MAIN_VARIANT (type_decays_to (type));
2713 if (enum_p && UNSCOPED_ENUM_P (type))
2714 VEC_safe_push (tree, gc, types[i], type);
2715 if (INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (type))
2716 type = type_promotes_to (type);
2718 VEC_safe_push (tree, gc, types[i], type);
2722 /* Run through the possible parameter types of both arguments,
2723 creating candidates with those parameter types. */
2724 FOR_EACH_VEC_ELT_REVERSE (tree, types[0], ix, t)
2729 if (!VEC_empty (tree, types[1]))
2730 FOR_EACH_VEC_ELT_REVERSE (tree, types[1], jx, u)
2731 add_builtin_candidate
2732 (candidates, code, code2, fnname, t,
2733 u, args, argtypes, flags);
2735 add_builtin_candidate
2736 (candidates, code, code2, fnname, t,
2737 NULL_TREE, args, argtypes, flags);
2740 release_tree_vector (types[0]);
2741 release_tree_vector (types[1]);
2745 /* If TMPL can be successfully instantiated as indicated by
2746 EXPLICIT_TARGS and ARGLIST, adds the instantiation to CANDIDATES.
2748 TMPL is the template. EXPLICIT_TARGS are any explicit template
2749 arguments. ARGLIST is the arguments provided at the call-site.
2750 This does not change ARGLIST. The RETURN_TYPE is the desired type
2751 for conversion operators. If OBJ is NULL_TREE, FLAGS and CTYPE are
2752 as for add_function_candidate. If an OBJ is supplied, FLAGS and
2753 CTYPE are ignored, and OBJ is as for add_conv_candidate. */
2755 static struct z_candidate*
2756 add_template_candidate_real (struct z_candidate **candidates, tree tmpl,
2757 tree ctype, tree explicit_targs, tree first_arg,
2758 const VEC(tree,gc) *arglist, tree return_type,
2759 tree access_path, tree conversion_path,
2760 int flags, tree obj, unification_kind_t strict)
2762 int ntparms = DECL_NTPARMS (tmpl);
2763 tree targs = make_tree_vec (ntparms);
2764 unsigned int len = VEC_length (tree, arglist);
2765 unsigned int nargs = (first_arg == NULL_TREE ? 0 : 1) + len;
2766 unsigned int skip_without_in_chrg = 0;
2767 tree first_arg_without_in_chrg = first_arg;
2768 tree *args_without_in_chrg;
2769 unsigned int nargs_without_in_chrg;
2770 unsigned int ia, ix;
2772 struct z_candidate *cand;
2775 struct rejection_reason *reason = NULL;
2777 /* We don't do deduction on the in-charge parameter, the VTT
2778 parameter or 'this'. */
2779 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (tmpl))
2781 if (first_arg_without_in_chrg != NULL_TREE)
2782 first_arg_without_in_chrg = NULL_TREE;
2784 ++skip_without_in_chrg;
2787 if ((DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (tmpl)
2788 || DECL_BASE_CONSTRUCTOR_P (tmpl))
2789 && CLASSTYPE_VBASECLASSES (DECL_CONTEXT (tmpl)))
2791 if (first_arg_without_in_chrg != NULL_TREE)
2792 first_arg_without_in_chrg = NULL_TREE;
2794 ++skip_without_in_chrg;
2797 if (len < skip_without_in_chrg)
2800 nargs_without_in_chrg = ((first_arg_without_in_chrg != NULL_TREE ? 1 : 0)
2801 + (len - skip_without_in_chrg));
2802 args_without_in_chrg = XALLOCAVEC (tree, nargs_without_in_chrg);
2804 if (first_arg_without_in_chrg != NULL_TREE)
2806 args_without_in_chrg[ia] = first_arg_without_in_chrg;
2809 for (ix = skip_without_in_chrg;
2810 VEC_iterate (tree, arglist, ix, arg);
2813 args_without_in_chrg[ia] = arg;
2816 gcc_assert (ia == nargs_without_in_chrg);
2818 i = fn_type_unification (tmpl, explicit_targs, targs,
2819 args_without_in_chrg,
2820 nargs_without_in_chrg,
2821 return_type, strict, flags);
2826 fn = instantiate_template (tmpl, targs, tf_none);
2827 if (fn == error_mark_node)
2832 A member function template is never instantiated to perform the
2833 copy of a class object to an object of its class type.
2835 It's a little unclear what this means; the standard explicitly
2836 does allow a template to be used to copy a class. For example,
2841 template <class T> A(const T&);
2844 void g () { A a (f ()); }
2846 the member template will be used to make the copy. The section
2847 quoted above appears in the paragraph that forbids constructors
2848 whose only parameter is (a possibly cv-qualified variant of) the
2849 class type, and a logical interpretation is that the intent was
2850 to forbid the instantiation of member templates which would then
2852 if (DECL_CONSTRUCTOR_P (fn) && nargs == 2)
2854 tree arg_types = FUNCTION_FIRST_USER_PARMTYPE (fn);
2855 if (arg_types && same_type_p (TYPE_MAIN_VARIANT (TREE_VALUE (arg_types)),
2860 if (obj != NULL_TREE)
2861 /* Aha, this is a conversion function. */
2862 cand = add_conv_candidate (candidates, fn, obj, first_arg, arglist,
2863 access_path, conversion_path);
2865 cand = add_function_candidate (candidates, fn, ctype,
2866 first_arg, arglist, access_path,
2867 conversion_path, flags);
2868 if (DECL_TI_TEMPLATE (fn) != tmpl)
2869 /* This situation can occur if a member template of a template
2870 class is specialized. Then, instantiate_template might return
2871 an instantiation of the specialization, in which case the
2872 DECL_TI_TEMPLATE field will point at the original
2873 specialization. For example:
2875 template <class T> struct S { template <class U> void f(U);
2876 template <> void f(int) {}; };
2880 Here, TMPL will be template <class U> S<double>::f(U).
2881 And, instantiate template will give us the specialization
2882 template <> S<double>::f(int). But, the DECL_TI_TEMPLATE field
2883 for this will point at template <class T> template <> S<T>::f(int),
2884 so that we can find the definition. For the purposes of
2885 overload resolution, however, we want the original TMPL. */
2886 cand->template_decl = build_template_info (tmpl, targs);
2888 cand->template_decl = DECL_TEMPLATE_INFO (fn);
2889 cand->explicit_targs = explicit_targs;
2893 return add_candidate (candidates, tmpl, first_arg, arglist, nargs, NULL,
2894 access_path, conversion_path, 0, reason);
2898 static struct z_candidate *
2899 add_template_candidate (struct z_candidate **candidates, tree tmpl, tree ctype,
2900 tree explicit_targs, tree first_arg,
2901 const VEC(tree,gc) *arglist, tree return_type,
2902 tree access_path, tree conversion_path, int flags,
2903 unification_kind_t strict)
2906 add_template_candidate_real (candidates, tmpl, ctype,
2907 explicit_targs, first_arg, arglist,
2908 return_type, access_path, conversion_path,
2909 flags, NULL_TREE, strict);
2913 static struct z_candidate *
2914 add_template_conv_candidate (struct z_candidate **candidates, tree tmpl,
2915 tree obj, tree first_arg,
2916 const VEC(tree,gc) *arglist,
2917 tree return_type, tree access_path,
2918 tree conversion_path)
2921 add_template_candidate_real (candidates, tmpl, NULL_TREE, NULL_TREE,
2922 first_arg, arglist, return_type, access_path,
2923 conversion_path, 0, obj, DEDUCE_CONV);
2926 /* The CANDS are the set of candidates that were considered for
2927 overload resolution. Return the set of viable candidates, or CANDS
2928 if none are viable. If any of the candidates were viable, set
2929 *ANY_VIABLE_P to true. STRICT_P is true if a candidate should be
2930 considered viable only if it is strictly viable. */
2932 static struct z_candidate*
2933 splice_viable (struct z_candidate *cands,
2937 struct z_candidate *viable;
2938 struct z_candidate **last_viable;
2939 struct z_candidate **cand;
2942 last_viable = &viable;
2943 *any_viable_p = false;
2948 struct z_candidate *c = *cand;
2949 if (strict_p ? c->viable == 1 : c->viable)
2954 last_viable = &c->next;
2955 *any_viable_p = true;
2961 return viable ? viable : cands;
2965 any_strictly_viable (struct z_candidate *cands)
2967 for (; cands; cands = cands->next)
2968 if (cands->viable == 1)
2973 /* OBJ is being used in an expression like "OBJ.f (...)". In other
2974 words, it is about to become the "this" pointer for a member
2975 function call. Take the address of the object. */
2978 build_this (tree obj)
2980 /* In a template, we are only concerned about the type of the
2981 expression, so we can take a shortcut. */
2982 if (processing_template_decl)
2983 return build_address (obj);
2985 return cp_build_addr_expr (obj, tf_warning_or_error);
2988 /* Returns true iff functions are equivalent. Equivalent functions are
2989 not '==' only if one is a function-local extern function or if
2990 both are extern "C". */
2993 equal_functions (tree fn1, tree fn2)
2995 if (TREE_CODE (fn1) != TREE_CODE (fn2))
2997 if (TREE_CODE (fn1) == TEMPLATE_DECL)
2999 if (DECL_LOCAL_FUNCTION_P (fn1) || DECL_LOCAL_FUNCTION_P (fn2)
3000 || DECL_EXTERN_C_FUNCTION_P (fn1))
3001 return decls_match (fn1, fn2);
3005 /* Print information about a candidate being rejected due to INFO. */
3008 print_conversion_rejection (location_t loc, struct conversion_info *info)
3010 if (info->n_arg == -1)
3011 /* Conversion of implicit `this' argument failed. */
3012 inform (loc, " no known conversion for implicit "
3013 "%<this%> parameter from %qT to %qT",
3014 info->from_type, info->to_type);
3016 inform (loc, " no known conversion for argument %d from %qT to %qT",
3017 info->n_arg+1, info->from_type, info->to_type);
3020 /* Print information about one overload candidate CANDIDATE. MSGSTR
3021 is the text to print before the candidate itself.
3023 NOTE: Unlike most diagnostic functions in GCC, MSGSTR is expected
3024 to have been run through gettext by the caller. This wart makes
3025 life simpler in print_z_candidates and for the translators. */
3028 print_z_candidate (const char *msgstr, struct z_candidate *candidate)
3030 const char *msg = (msgstr == NULL
3032 : ACONCAT ((msgstr, " ", NULL)));
3033 location_t loc = location_of (candidate->fn);
3035 if (TREE_CODE (candidate->fn) == IDENTIFIER_NODE)
3037 if (candidate->num_convs == 3)
3038 inform (input_location, "%s%D(%T, %T, %T) <built-in>", msg, candidate->fn,
3039 candidate->convs[0]->type,
3040 candidate->convs[1]->type,
3041 candidate->convs[2]->type);
3042 else if (candidate->num_convs == 2)
3043 inform (input_location, "%s%D(%T, %T) <built-in>", msg, candidate->fn,
3044 candidate->convs[0]->type,
3045 candidate->convs[1]->type);
3047 inform (input_location, "%s%D(%T) <built-in>", msg, candidate->fn,
3048 candidate->convs[0]->type);
3050 else if (TYPE_P (candidate->fn))
3051 inform (input_location, "%s%T <conversion>", msg, candidate->fn);
3052 else if (candidate->viable == -1)
3053 inform (loc, "%s%#D <near match>", msg, candidate->fn);
3054 else if (DECL_DELETED_FN (STRIP_TEMPLATE (candidate->fn)))
3055 inform (loc, "%s%#D <deleted>", msg, candidate->fn);
3057 inform (loc, "%s%#D", msg, candidate->fn);
3058 /* Give the user some information about why this candidate failed. */
3059 if (candidate->reason != NULL)
3061 struct rejection_reason *r = candidate->reason;
3066 inform_n (loc, r->u.arity.expected,
3067 " candidate expects %d argument, %d provided",
3068 " candidate expects %d arguments, %d provided",
3069 r->u.arity.expected, r->u.arity.actual);
3071 case rr_arg_conversion:
3072 print_conversion_rejection (loc, &r->u.conversion);
3074 case rr_bad_arg_conversion:
3075 print_conversion_rejection (loc, &r->u.bad_conversion);
3079 /* This candidate didn't have any issues or we failed to
3080 handle a particular code. Either way... */
3087 print_z_candidates (location_t loc, struct z_candidate *candidates)
3089 struct z_candidate *cand1;
3090 struct z_candidate **cand2;
3096 /* Remove non-viable deleted candidates. */
3098 for (cand2 = &cand1; *cand2; )
3100 if (TREE_CODE ((*cand2)->fn) == FUNCTION_DECL
3101 && !(*cand2)->viable
3102 && DECL_DELETED_FN ((*cand2)->fn))
3103 *cand2 = (*cand2)->next;
3105 cand2 = &(*cand2)->next;
3107 /* ...if there are any non-deleted ones. */
3111 /* There may be duplicates in the set of candidates. We put off
3112 checking this condition as long as possible, since we have no way
3113 to eliminate duplicates from a set of functions in less than n^2
3114 time. Now we are about to emit an error message, so it is more
3115 permissible to go slowly. */
3116 for (cand1 = candidates; cand1; cand1 = cand1->next)
3118 tree fn = cand1->fn;
3119 /* Skip builtin candidates and conversion functions. */
3122 cand2 = &cand1->next;
3125 if (DECL_P ((*cand2)->fn)
3126 && equal_functions (fn, (*cand2)->fn))
3127 *cand2 = (*cand2)->next;
3129 cand2 = &(*cand2)->next;
3133 for (n_candidates = 0, cand1 = candidates; cand1; cand1 = cand1->next)
3136 inform_n (loc, n_candidates, "candidate is:", "candidates are:");
3137 for (; candidates; candidates = candidates->next)
3138 print_z_candidate (NULL, candidates);
3141 /* USER_SEQ is a user-defined conversion sequence, beginning with a
3142 USER_CONV. STD_SEQ is the standard conversion sequence applied to
3143 the result of the conversion function to convert it to the final
3144 desired type. Merge the two sequences into a single sequence,
3145 and return the merged sequence. */
3148 merge_conversion_sequences (conversion *user_seq, conversion *std_seq)
3152 gcc_assert (user_seq->kind == ck_user);
3154 /* Find the end of the second conversion sequence. */
3156 while ((*t)->kind != ck_identity)
3157 t = &((*t)->u.next);
3159 /* Replace the identity conversion with the user conversion
3163 /* The entire sequence is a user-conversion sequence. */
3164 std_seq->user_conv_p = true;
3169 /* Handle overload resolution for initializing an object of class type from
3170 an initializer list. First we look for a suitable constructor that
3171 takes a std::initializer_list; if we don't find one, we then look for a
3172 non-list constructor.
3174 Parameters are as for add_candidates, except that the arguments are in
3175 the form of a CONSTRUCTOR (the initializer list) rather than a VEC, and
3176 the RETURN_TYPE parameter is replaced by TOTYPE, the desired type. */
3179 add_list_candidates (tree fns, tree first_arg,
3180 tree init_list, tree totype,
3181 tree explicit_targs, bool template_only,
3182 tree conversion_path, tree access_path,
3184 struct z_candidate **candidates)
3188 gcc_assert (*candidates == NULL);
3190 /* For list-initialization we consider explicit constructors, but
3191 give an error if one is selected. */
3192 flags &= ~LOOKUP_ONLYCONVERTING;
3193 /* And we don't allow narrowing conversions. We also use this flag to
3194 avoid the copy constructor call for copy-list-initialization. */
3195 flags |= LOOKUP_NO_NARROWING;
3197 /* Always use the default constructor if the list is empty (DR 990). */
3198 if (CONSTRUCTOR_NELTS (init_list) == 0
3199 && TYPE_HAS_DEFAULT_CONSTRUCTOR (totype))
3201 /* If the class has a list ctor, try passing the list as a single
3202 argument first, but only consider list ctors. */
3203 else if (TYPE_HAS_LIST_CTOR (totype))
3205 flags |= LOOKUP_LIST_ONLY;
3206 args = make_tree_vector_single (init_list);
3207 add_candidates (fns, first_arg, args, NULL_TREE,
3208 explicit_targs, template_only, conversion_path,
3209 access_path, flags, candidates);
3210 if (any_strictly_viable (*candidates))
3214 args = ctor_to_vec (init_list);
3216 /* We aren't looking for list-ctors anymore. */
3217 flags &= ~LOOKUP_LIST_ONLY;
3218 /* We allow more user-defined conversions within an init-list. */
3219 flags &= ~LOOKUP_NO_CONVERSION;
3220 /* But not for the copy ctor. */
3221 flags |= LOOKUP_NO_COPY_CTOR_CONVERSION;
3223 add_candidates (fns, first_arg, args, NULL_TREE,
3224 explicit_targs, template_only, conversion_path,
3225 access_path, flags, candidates);
3228 /* Returns the best overload candidate to perform the requested
3229 conversion. This function is used for three the overloading situations
3230 described in [over.match.copy], [over.match.conv], and [over.match.ref].
3231 If TOTYPE is a REFERENCE_TYPE, we're trying to find an lvalue binding as
3232 per [dcl.init.ref], so we ignore temporary bindings. */
3234 static struct z_candidate *
3235 build_user_type_conversion_1 (tree totype, tree expr, int flags)
3237 struct z_candidate *candidates, *cand;
3238 tree fromtype = TREE_TYPE (expr);
3239 tree ctors = NULL_TREE;
3240 tree conv_fns = NULL_TREE;
3241 conversion *conv = NULL;
3242 tree first_arg = NULL_TREE;
3243 VEC(tree,gc) *args = NULL;
3247 /* We represent conversion within a hierarchy using RVALUE_CONV and
3248 BASE_CONV, as specified by [over.best.ics]; these become plain
3249 constructor calls, as specified in [dcl.init]. */
3250 gcc_assert (!MAYBE_CLASS_TYPE_P (fromtype) || !MAYBE_CLASS_TYPE_P (totype)
3251 || !DERIVED_FROM_P (totype, fromtype));
3253 if (MAYBE_CLASS_TYPE_P (totype))
3254 /* Use lookup_fnfields_slot instead of lookup_fnfields to avoid
3255 creating a garbage BASELINK; constructors can't be inherited. */
3256 ctors = lookup_fnfields_slot (totype, complete_ctor_identifier);
3258 if (MAYBE_CLASS_TYPE_P (fromtype))
3260 tree to_nonref = non_reference (totype);
3261 if (same_type_ignoring_top_level_qualifiers_p (to_nonref, fromtype) ||
3262 (CLASS_TYPE_P (to_nonref) && CLASS_TYPE_P (fromtype)
3263 && DERIVED_FROM_P (to_nonref, fromtype)))
3265 /* [class.conv.fct] A conversion function is never used to
3266 convert a (possibly cv-qualified) object to the (possibly
3267 cv-qualified) same object type (or a reference to it), to a
3268 (possibly cv-qualified) base class of that type (or a
3269 reference to it)... */
3272 conv_fns = lookup_conversions (fromtype);
3276 flags |= LOOKUP_NO_CONVERSION;
3277 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3278 flags |= LOOKUP_NO_NARROWING;
3280 /* It's OK to bind a temporary for converting constructor arguments, but
3281 not in converting the return value of a conversion operator. */
3282 convflags = ((flags & LOOKUP_NO_TEMP_BIND) | LOOKUP_NO_CONVERSION);
3283 flags &= ~LOOKUP_NO_TEMP_BIND;
3287 int ctorflags = flags;
3289 first_arg = build_int_cst (build_pointer_type (totype), 0);
3291 /* We should never try to call the abstract or base constructor
3293 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (OVL_CURRENT (ctors))
3294 && !DECL_HAS_VTT_PARM_P (OVL_CURRENT (ctors)));
3296 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
3298 /* List-initialization. */
3299 add_list_candidates (ctors, first_arg, expr, totype, NULL_TREE,
3300 false, TYPE_BINFO (totype), TYPE_BINFO (totype),
3301 ctorflags, &candidates);
3305 args = make_tree_vector_single (expr);
3306 add_candidates (ctors, first_arg, args, NULL_TREE, NULL_TREE, false,
3307 TYPE_BINFO (totype), TYPE_BINFO (totype),
3308 ctorflags, &candidates);
3311 for (cand = candidates; cand; cand = cand->next)
3313 cand->second_conv = build_identity_conv (totype, NULL_TREE);
3315 /* If totype isn't a reference, and LOOKUP_NO_TEMP_BIND isn't
3316 set, then this is copy-initialization. In that case, "The
3317 result of the call is then used to direct-initialize the
3318 object that is the destination of the copy-initialization."
3321 We represent this in the conversion sequence with an
3322 rvalue conversion, which means a constructor call. */
3323 if (TREE_CODE (totype) != REFERENCE_TYPE
3324 && !(convflags & LOOKUP_NO_TEMP_BIND))
3326 = build_conv (ck_rvalue, totype, cand->second_conv);
3331 first_arg = build_this (expr);
3333 for (; conv_fns; conv_fns = TREE_CHAIN (conv_fns))
3335 tree conversion_path = TREE_PURPOSE (conv_fns);
3336 struct z_candidate *old_candidates;
3338 /* If we are called to convert to a reference type, we are trying to
3339 find an lvalue binding, so don't even consider temporaries. If
3340 we don't find an lvalue binding, the caller will try again to
3341 look for a temporary binding. */
3342 if (TREE_CODE (totype) == REFERENCE_TYPE)
3343 convflags |= LOOKUP_NO_TEMP_BIND;
3345 old_candidates = candidates;
3346 add_candidates (TREE_VALUE (conv_fns), first_arg, NULL, totype,
3348 conversion_path, TYPE_BINFO (fromtype),
3349 flags, &candidates);
3351 for (cand = candidates; cand != old_candidates; cand = cand->next)
3354 = implicit_conversion (totype,
3355 TREE_TYPE (TREE_TYPE (cand->fn)),
3357 /*c_cast_p=*/false, convflags);
3359 /* If LOOKUP_NO_TEMP_BIND isn't set, then this is
3360 copy-initialization. In that case, "The result of the
3361 call is then used to direct-initialize the object that is
3362 the destination of the copy-initialization." [dcl.init]
3364 We represent this in the conversion sequence with an
3365 rvalue conversion, which means a constructor call. But
3366 don't add a second rvalue conversion if there's already
3367 one there. Which there really shouldn't be, but it's
3368 harmless since we'd add it here anyway. */
3369 if (ics && MAYBE_CLASS_TYPE_P (totype) && ics->kind != ck_rvalue
3370 && !(convflags & LOOKUP_NO_TEMP_BIND))
3371 ics = build_conv (ck_rvalue, totype, ics);
3373 cand->second_conv = ics;
3377 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3379 cand->reason = arg_conversion_rejection (NULL_TREE, -1,
3382 else if (cand->viable == 1 && ics->bad_p)
3384 tree rettype = TREE_TYPE (TREE_TYPE (cand->fn));
3387 = bad_arg_conversion_rejection (NULL_TREE, -1,
3393 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3397 release_tree_vector (args);
3401 cand = tourney (candidates);
3404 if (flags & LOOKUP_COMPLAIN)
3406 error ("conversion from %qT to %qT is ambiguous",
3408 print_z_candidates (location_of (expr), candidates);
3411 cand = candidates; /* any one will do */
3412 cand->second_conv = build_ambiguous_conv (totype, expr);
3413 cand->second_conv->user_conv_p = true;
3414 if (!any_strictly_viable (candidates))
3415 cand->second_conv->bad_p = true;
3416 /* If there are viable candidates, don't set ICS_BAD_FLAG; an
3417 ambiguous conversion is no worse than another user-defined
3423 /* Build the user conversion sequence. */
3426 (DECL_CONSTRUCTOR_P (cand->fn)
3427 ? totype : non_reference (TREE_TYPE (TREE_TYPE (cand->fn)))),
3428 build_identity_conv (TREE_TYPE (expr), expr));
3431 /* Remember that this was a list-initialization. */
3432 if (flags & LOOKUP_NO_NARROWING)
3433 conv->check_narrowing = true;
3435 /* Combine it with the second conversion sequence. */
3436 cand->second_conv = merge_conversion_sequences (conv,
3439 if (cand->viable == -1)
3440 cand->second_conv->bad_p = true;
3446 build_user_type_conversion (tree totype, tree expr, int flags)
3448 struct z_candidate *cand
3449 = build_user_type_conversion_1 (totype, expr, flags);
3453 if (cand->second_conv->kind == ck_ambig)
3454 return error_mark_node;
3455 expr = convert_like (cand->second_conv, expr, tf_warning_or_error);
3456 return convert_from_reference (expr);
3461 /* Subroutine of convert_nontype_argument.
3463 EXPR is an argument for a template non-type parameter of integral or
3464 enumeration type. Do any necessary conversions (that are permitted for
3465 non-type arguments) to convert it to the parameter type.
3467 If conversion is successful, returns the converted expression;
3468 otherwise, returns error_mark_node. */
3471 build_integral_nontype_arg_conv (tree type, tree expr, tsubst_flags_t complain)
3477 if (error_operand_p (expr))
3478 return error_mark_node;
3480 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
3482 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3483 p = conversion_obstack_alloc (0);
3485 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
3489 /* for a non-type template-parameter of integral or
3490 enumeration type, integral promotions (4.5) and integral
3491 conversions (4.7) are applied. */
3492 /* It should be sufficient to check the outermost conversion step, since
3493 there are no qualification conversions to integer type. */
3497 /* A conversion function is OK. If it isn't constexpr, we'll
3498 complain later that the argument isn't constant. */
3500 /* The lvalue-to-rvalue conversion is OK. */
3506 t = conv->u.next->type;
3507 if (INTEGRAL_OR_ENUMERATION_TYPE_P (t))
3510 if (complain & tf_error)
3511 error ("conversion from %qT to %qT not considered for "
3512 "non-type template argument", t, type);
3513 /* and fall through. */
3521 expr = convert_like (conv, expr, complain);
3523 expr = error_mark_node;
3525 /* Free all the conversions we allocated. */
3526 obstack_free (&conversion_obstack, p);
3531 /* Do any initial processing on the arguments to a function call. */
3533 static VEC(tree,gc) *
3534 resolve_args (VEC(tree,gc) *args, tsubst_flags_t complain)
3539 FOR_EACH_VEC_ELT (tree, args, ix, arg)
3541 if (error_operand_p (arg))
3543 else if (VOID_TYPE_P (TREE_TYPE (arg)))
3545 if (complain & tf_error)
3546 error ("invalid use of void expression");
3549 else if (invalid_nonstatic_memfn_p (arg, tf_warning_or_error))
3555 /* Perform overload resolution on FN, which is called with the ARGS.
3557 Return the candidate function selected by overload resolution, or
3558 NULL if the event that overload resolution failed. In the case
3559 that overload resolution fails, *CANDIDATES will be the set of
3560 candidates considered, and ANY_VIABLE_P will be set to true or
3561 false to indicate whether or not any of the candidates were
3564 The ARGS should already have gone through RESOLVE_ARGS before this
3565 function is called. */
3567 static struct z_candidate *
3568 perform_overload_resolution (tree fn,
3569 const VEC(tree,gc) *args,
3570 struct z_candidate **candidates,
3573 struct z_candidate *cand;
3574 tree explicit_targs = NULL_TREE;
3575 int template_only = 0;
3578 *any_viable_p = true;
3581 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL
3582 || TREE_CODE (fn) == TEMPLATE_DECL
3583 || TREE_CODE (fn) == OVERLOAD
3584 || TREE_CODE (fn) == TEMPLATE_ID_EXPR);
3586 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3588 explicit_targs = TREE_OPERAND (fn, 1);
3589 fn = TREE_OPERAND (fn, 0);
3593 /* Add the various candidate functions. */
3594 add_candidates (fn, NULL_TREE, args, NULL_TREE,
3595 explicit_targs, template_only,
3596 /*conversion_path=*/NULL_TREE,
3597 /*access_path=*/NULL_TREE,
3601 *candidates = splice_viable (*candidates, pedantic, any_viable_p);
3605 cand = tourney (*candidates);
3609 /* Print an error message about being unable to build a call to FN with
3610 ARGS. ANY_VIABLE_P indicates whether any candidate functions could
3611 be located; CANDIDATES is a possibly empty list of such
3615 print_error_for_call_failure (tree fn, VEC(tree,gc) *args, bool any_viable_p,
3616 struct z_candidate *candidates)
3618 tree name = DECL_NAME (OVL_CURRENT (fn));
3619 location_t loc = location_of (name);
3622 error_at (loc, "no matching function for call to %<%D(%A)%>",
3623 name, build_tree_list_vec (args));
3625 error_at (loc, "call of overloaded %<%D(%A)%> is ambiguous",
3626 name, build_tree_list_vec (args));
3628 print_z_candidates (loc, candidates);
3631 /* Return an expression for a call to FN (a namespace-scope function,
3632 or a static member function) with the ARGS. This may change
3636 build_new_function_call (tree fn, VEC(tree,gc) **args, bool koenig_p,
3637 tsubst_flags_t complain)
3639 struct z_candidate *candidates, *cand;
3644 if (args != NULL && *args != NULL)
3646 *args = resolve_args (*args, complain);
3648 return error_mark_node;
3651 /* If this function was found without using argument dependent
3652 lookup, then we want to ignore any undeclared friend
3658 fn = remove_hidden_names (fn);
3661 if (complain & tf_error)
3662 print_error_for_call_failure (orig_fn, *args, false, NULL);
3663 return error_mark_node;
3667 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3668 p = conversion_obstack_alloc (0);
3670 cand = perform_overload_resolution (fn, *args, &candidates, &any_viable_p);
3674 if (complain & tf_error)
3676 if (!any_viable_p && candidates && ! candidates->next
3677 && (TREE_CODE (candidates->fn) == FUNCTION_DECL))
3678 return cp_build_function_call_vec (candidates->fn, args, complain);
3679 if (TREE_CODE (fn) == TEMPLATE_ID_EXPR)
3680 fn = TREE_OPERAND (fn, 0);
3681 print_error_for_call_failure (fn, *args, any_viable_p, candidates);
3683 result = error_mark_node;
3686 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3688 /* Free all the conversions we allocated. */
3689 obstack_free (&conversion_obstack, p);
3694 /* Build a call to a global operator new. FNNAME is the name of the
3695 operator (either "operator new" or "operator new[]") and ARGS are
3696 the arguments provided. This may change ARGS. *SIZE points to the
3697 total number of bytes required by the allocation, and is updated if
3698 that is changed here. *COOKIE_SIZE is non-NULL if a cookie should
3699 be used. If this function determines that no cookie should be
3700 used, after all, *COOKIE_SIZE is set to NULL_TREE. If FN is
3701 non-NULL, it will be set, upon return, to the allocation function
3705 build_operator_new_call (tree fnname, VEC(tree,gc) **args,
3706 tree *size, tree *cookie_size,
3710 struct z_candidate *candidates;
3711 struct z_candidate *cand;
3716 VEC_safe_insert (tree, gc, *args, 0, *size);
3717 *args = resolve_args (*args, tf_warning_or_error);
3719 return error_mark_node;
3725 If this lookup fails to find the name, or if the allocated type
3726 is not a class type, the allocation function's name is looked
3727 up in the global scope.
3729 we disregard block-scope declarations of "operator new". */
3730 fns = lookup_function_nonclass (fnname, *args, /*block_p=*/false);
3732 /* Figure out what function is being called. */
3733 cand = perform_overload_resolution (fns, *args, &candidates, &any_viable_p);
3735 /* If no suitable function could be found, issue an error message
3739 print_error_for_call_failure (fns, *args, any_viable_p, candidates);
3740 return error_mark_node;
3743 /* If a cookie is required, add some extra space. Whether
3744 or not a cookie is required cannot be determined until
3745 after we know which function was called. */
3748 bool use_cookie = true;
3749 if (!abi_version_at_least (2))
3751 /* In G++ 3.2, the check was implemented incorrectly; it
3752 looked at the placement expression, rather than the
3753 type of the function. */
3754 if (VEC_length (tree, *args) == 2
3755 && same_type_p (TREE_TYPE (VEC_index (tree, *args, 1)),
3763 arg_types = TYPE_ARG_TYPES (TREE_TYPE (cand->fn));
3764 /* Skip the size_t parameter. */
3765 arg_types = TREE_CHAIN (arg_types);
3766 /* Check the remaining parameters (if any). */
3768 && TREE_CHAIN (arg_types) == void_list_node
3769 && same_type_p (TREE_VALUE (arg_types),
3773 /* If we need a cookie, adjust the number of bytes allocated. */
3776 /* Update the total size. */
3777 *size = size_binop (PLUS_EXPR, *size, *cookie_size);
3778 /* Update the argument list to reflect the adjusted size. */
3779 VEC_replace (tree, *args, 0, *size);
3782 *cookie_size = NULL_TREE;
3785 /* Tell our caller which function we decided to call. */
3789 /* Build the CALL_EXPR. */
3790 return build_over_call (cand, LOOKUP_NORMAL, tf_warning_or_error);
3793 /* Build a new call to operator(). This may change ARGS. */
3796 build_op_call (tree obj, VEC(tree,gc) **args, tsubst_flags_t complain)
3798 struct z_candidate *candidates = 0, *cand;
3799 tree fns, convs, first_mem_arg = NULL_TREE;
3800 tree type = TREE_TYPE (obj);
3802 tree result = NULL_TREE;
3805 if (error_operand_p (obj))
3806 return error_mark_node;
3808 obj = prep_operand (obj);
3810 if (TYPE_PTRMEMFUNC_P (type))
3812 if (complain & tf_error)
3813 /* It's no good looking for an overloaded operator() on a
3814 pointer-to-member-function. */
3815 error ("pointer-to-member function %E cannot be called without an object; consider using .* or ->*", obj);
3816 return error_mark_node;
3819 if (TYPE_BINFO (type))
3821 fns = lookup_fnfields (TYPE_BINFO (type), ansi_opname (CALL_EXPR), 1);
3822 if (fns == error_mark_node)
3823 return error_mark_node;
3828 if (args != NULL && *args != NULL)
3830 *args = resolve_args (*args, complain);
3832 return error_mark_node;
3835 /* Get the high-water mark for the CONVERSION_OBSTACK. */
3836 p = conversion_obstack_alloc (0);
3840 first_mem_arg = build_this (obj);
3842 add_candidates (BASELINK_FUNCTIONS (fns),
3843 first_mem_arg, *args, NULL_TREE,
3845 BASELINK_BINFO (fns), BASELINK_ACCESS_BINFO (fns),
3846 LOOKUP_NORMAL, &candidates);
3849 convs = lookup_conversions (type);
3851 for (; convs; convs = TREE_CHAIN (convs))
3853 tree fns = TREE_VALUE (convs);
3854 tree totype = TREE_TYPE (convs);
3856 if ((TREE_CODE (totype) == POINTER_TYPE
3857 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3858 || (TREE_CODE (totype) == REFERENCE_TYPE
3859 && TREE_CODE (TREE_TYPE (totype)) == FUNCTION_TYPE)
3860 || (TREE_CODE (totype) == REFERENCE_TYPE
3861 && TREE_CODE (TREE_TYPE (totype)) == POINTER_TYPE
3862 && TREE_CODE (TREE_TYPE (TREE_TYPE (totype))) == FUNCTION_TYPE))
3863 for (; fns; fns = OVL_NEXT (fns))
3865 tree fn = OVL_CURRENT (fns);
3867 if (DECL_NONCONVERTING_P (fn))
3870 if (TREE_CODE (fn) == TEMPLATE_DECL)
3871 add_template_conv_candidate
3872 (&candidates, fn, obj, NULL_TREE, *args, totype,
3873 /*access_path=*/NULL_TREE,
3874 /*conversion_path=*/NULL_TREE);
3876 add_conv_candidate (&candidates, fn, obj, NULL_TREE,
3877 *args, /*conversion_path=*/NULL_TREE,
3878 /*access_path=*/NULL_TREE);
3882 candidates = splice_viable (candidates, pedantic, &any_viable_p);
3885 if (complain & tf_error)
3887 error ("no match for call to %<(%T) (%A)%>", TREE_TYPE (obj),
3888 build_tree_list_vec (*args));
3889 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3891 result = error_mark_node;
3895 cand = tourney (candidates);
3898 if (complain & tf_error)
3900 error ("call of %<(%T) (%A)%> is ambiguous",
3901 TREE_TYPE (obj), build_tree_list_vec (*args));
3902 print_z_candidates (location_of (TREE_TYPE (obj)), candidates);
3904 result = error_mark_node;
3906 /* Since cand->fn will be a type, not a function, for a conversion
3907 function, we must be careful not to unconditionally look at
3909 else if (TREE_CODE (cand->fn) == FUNCTION_DECL
3910 && DECL_OVERLOADED_OPERATOR_P (cand->fn) == CALL_EXPR)
3911 result = build_over_call (cand, LOOKUP_NORMAL, complain);
3914 obj = convert_like_with_context (cand->convs[0], obj, cand->fn, -1,
3916 obj = convert_from_reference (obj);
3917 result = cp_build_function_call_vec (obj, args, complain);
3921 /* Free all the conversions we allocated. */
3922 obstack_free (&conversion_obstack, p);
3928 op_error (enum tree_code code, enum tree_code code2,
3929 tree arg1, tree arg2, tree arg3, bool match)
3933 if (code == MODIFY_EXPR)
3934 opname = assignment_operator_name_info[code2].name;
3936 opname = operator_name_info[code].name;
3942 error ("ambiguous overload for ternary %<operator?:%> "
3943 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3945 error ("no match for ternary %<operator?:%> "
3946 "in %<%E ? %E : %E%>", arg1, arg2, arg3);
3949 case POSTINCREMENT_EXPR:
3950 case POSTDECREMENT_EXPR:
3952 error ("ambiguous overload for %<operator%s%> in %<%E%s%>",
3953 opname, arg1, opname);
3955 error ("no match for %<operator%s%> in %<%E%s%>",
3956 opname, arg1, opname);
3961 error ("ambiguous overload for %<operator[]%> in %<%E[%E]%>",
3964 error ("no match for %<operator[]%> in %<%E[%E]%>",
3971 error ("ambiguous overload for %qs in %<%s %E%>",
3972 opname, opname, arg1);
3974 error ("no match for %qs in %<%s %E%>",
3975 opname, opname, arg1);
3981 error ("ambiguous overload for %<operator%s%> in %<%E %s %E%>",
3982 opname, arg1, opname, arg2);
3984 error ("no match for %<operator%s%> in %<%E %s %E%>",
3985 opname, arg1, opname, arg2);
3988 error ("ambiguous overload for %<operator%s%> in %<%s%E%>",
3989 opname, opname, arg1);
3991 error ("no match for %<operator%s%> in %<%s%E%>",
3992 opname, opname, arg1);
3997 /* Return the implicit conversion sequence that could be used to
3998 convert E1 to E2 in [expr.cond]. */
4001 conditional_conversion (tree e1, tree e2)
4003 tree t1 = non_reference (TREE_TYPE (e1));
4004 tree t2 = non_reference (TREE_TYPE (e2));
4010 If E2 is an lvalue: E1 can be converted to match E2 if E1 can be
4011 implicitly converted (clause _conv_) to the type "reference to
4012 T2", subject to the constraint that in the conversion the
4013 reference must bind directly (_dcl.init.ref_) to E1. */
4014 if (real_lvalue_p (e2))
4016 conv = implicit_conversion (build_reference_type (t2),
4020 LOOKUP_NO_TEMP_BIND|LOOKUP_ONLYCONVERTING);
4027 If E1 and E2 have class type, and the underlying class types are
4028 the same or one is a base class of the other: E1 can be converted
4029 to match E2 if the class of T2 is the same type as, or a base
4030 class of, the class of T1, and the cv-qualification of T2 is the
4031 same cv-qualification as, or a greater cv-qualification than, the
4032 cv-qualification of T1. If the conversion is applied, E1 is
4033 changed to an rvalue of type T2 that still refers to the original
4034 source class object (or the appropriate subobject thereof). */
4035 if (CLASS_TYPE_P (t1) && CLASS_TYPE_P (t2)
4036 && ((good_base = DERIVED_FROM_P (t2, t1)) || DERIVED_FROM_P (t1, t2)))
4038 if (good_base && at_least_as_qualified_p (t2, t1))
4040 conv = build_identity_conv (t1, e1);
4041 if (!same_type_p (TYPE_MAIN_VARIANT (t1),
4042 TYPE_MAIN_VARIANT (t2)))
4043 conv = build_conv (ck_base, t2, conv);
4045 conv = build_conv (ck_rvalue, t2, conv);
4054 Otherwise: E1 can be converted to match E2 if E1 can be implicitly
4055 converted to the type that expression E2 would have if E2 were
4056 converted to an rvalue (or the type it has, if E2 is an rvalue). */
4057 return implicit_conversion (t2, t1, e1, /*c_cast_p=*/false,
4061 /* Implement [expr.cond]. ARG1, ARG2, and ARG3 are the three
4062 arguments to the conditional expression. */
4065 build_conditional_expr (tree arg1, tree arg2, tree arg3,
4066 tsubst_flags_t complain)
4070 tree result = NULL_TREE;
4071 tree result_type = NULL_TREE;
4072 bool lvalue_p = true;
4073 struct z_candidate *candidates = 0;
4074 struct z_candidate *cand;
4077 /* As a G++ extension, the second argument to the conditional can be
4078 omitted. (So that `a ? : c' is roughly equivalent to `a ? a :
4079 c'.) If the second operand is omitted, make sure it is
4080 calculated only once. */
4083 if (complain & tf_error)
4084 pedwarn (input_location, OPT_pedantic,
4085 "ISO C++ forbids omitting the middle term of a ?: expression");
4087 /* Make sure that lvalues remain lvalues. See g++.oliva/ext1.C. */
4088 if (real_lvalue_p (arg1))
4089 arg2 = arg1 = stabilize_reference (arg1);
4091 arg2 = arg1 = save_expr (arg1);
4096 The first expression is implicitly converted to bool (clause
4098 arg1 = perform_implicit_conversion_flags (boolean_type_node, arg1, complain,
4101 /* If something has already gone wrong, just pass that fact up the
4103 if (error_operand_p (arg1)
4104 || error_operand_p (arg2)
4105 || error_operand_p (arg3))
4106 return error_mark_node;
4110 If either the second or the third operand has type (possibly
4111 cv-qualified) void, then the lvalue-to-rvalue (_conv.lval_),
4112 array-to-pointer (_conv.array_), and function-to-pointer
4113 (_conv.func_) standard conversions are performed on the second
4114 and third operands. */
4115 arg2_type = unlowered_expr_type (arg2);
4116 arg3_type = unlowered_expr_type (arg3);
4117 if (VOID_TYPE_P (arg2_type) || VOID_TYPE_P (arg3_type))
4119 /* Do the conversions. We don't these for `void' type arguments
4120 since it can't have any effect and since decay_conversion
4121 does not handle that case gracefully. */
4122 if (!VOID_TYPE_P (arg2_type))
4123 arg2 = decay_conversion (arg2);
4124 if (!VOID_TYPE_P (arg3_type))
4125 arg3 = decay_conversion (arg3);
4126 arg2_type = TREE_TYPE (arg2);
4127 arg3_type = TREE_TYPE (arg3);
4131 One of the following shall hold:
4133 --The second or the third operand (but not both) is a
4134 throw-expression (_except.throw_); the result is of the
4135 type of the other and is an rvalue.
4137 --Both the second and the third operands have type void; the
4138 result is of type void and is an rvalue.
4140 We must avoid calling force_rvalue for expressions of type
4141 "void" because it will complain that their value is being
4143 if (TREE_CODE (arg2) == THROW_EXPR
4144 && TREE_CODE (arg3) != THROW_EXPR)
4146 if (!VOID_TYPE_P (arg3_type))
4147 arg3 = force_rvalue (arg3);
4148 arg3_type = TREE_TYPE (arg3);
4149 result_type = arg3_type;
4151 else if (TREE_CODE (arg2) != THROW_EXPR
4152 && TREE_CODE (arg3) == THROW_EXPR)
4154 if (!VOID_TYPE_P (arg2_type))
4155 arg2 = force_rvalue (arg2);
4156 arg2_type = TREE_TYPE (arg2);
4157 result_type = arg2_type;
4159 else if (VOID_TYPE_P (arg2_type) && VOID_TYPE_P (arg3_type))
4160 result_type = void_type_node;
4163 if (complain & tf_error)
4165 if (VOID_TYPE_P (arg2_type))
4166 error ("second operand to the conditional operator "
4167 "is of type %<void%>, "
4168 "but the third operand is neither a throw-expression "
4169 "nor of type %<void%>");
4171 error ("third operand to the conditional operator "
4172 "is of type %<void%>, "
4173 "but the second operand is neither a throw-expression "
4174 "nor of type %<void%>");
4176 return error_mark_node;
4180 goto valid_operands;
4184 Otherwise, if the second and third operand have different types,
4185 and either has (possibly cv-qualified) class type, an attempt is
4186 made to convert each of those operands to the type of the other. */
4187 else if (!same_type_p (arg2_type, arg3_type)
4188 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4193 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4194 p = conversion_obstack_alloc (0);
4196 conv2 = conditional_conversion (arg2, arg3);
4197 conv3 = conditional_conversion (arg3, arg2);
4201 If both can be converted, or one can be converted but the
4202 conversion is ambiguous, the program is ill-formed. If
4203 neither can be converted, the operands are left unchanged and
4204 further checking is performed as described below. If exactly
4205 one conversion is possible, that conversion is applied to the
4206 chosen operand and the converted operand is used in place of
4207 the original operand for the remainder of this section. */
4208 if ((conv2 && !conv2->bad_p
4209 && conv3 && !conv3->bad_p)
4210 || (conv2 && conv2->kind == ck_ambig)
4211 || (conv3 && conv3->kind == ck_ambig))
4213 error ("operands to ?: have different types %qT and %qT",
4214 arg2_type, arg3_type);
4215 result = error_mark_node;
4217 else if (conv2 && (!conv2->bad_p || !conv3))
4219 arg2 = convert_like (conv2, arg2, complain);
4220 arg2 = convert_from_reference (arg2);
4221 arg2_type = TREE_TYPE (arg2);
4222 /* Even if CONV2 is a valid conversion, the result of the
4223 conversion may be invalid. For example, if ARG3 has type
4224 "volatile X", and X does not have a copy constructor
4225 accepting a "volatile X&", then even if ARG2 can be
4226 converted to X, the conversion will fail. */
4227 if (error_operand_p (arg2))
4228 result = error_mark_node;
4230 else if (conv3 && (!conv3->bad_p || !conv2))
4232 arg3 = convert_like (conv3, arg3, complain);
4233 arg3 = convert_from_reference (arg3);
4234 arg3_type = TREE_TYPE (arg3);
4235 if (error_operand_p (arg3))
4236 result = error_mark_node;
4239 /* Free all the conversions we allocated. */
4240 obstack_free (&conversion_obstack, p);
4245 /* If, after the conversion, both operands have class type,
4246 treat the cv-qualification of both operands as if it were the
4247 union of the cv-qualification of the operands.
4249 The standard is not clear about what to do in this
4250 circumstance. For example, if the first operand has type
4251 "const X" and the second operand has a user-defined
4252 conversion to "volatile X", what is the type of the second
4253 operand after this step? Making it be "const X" (matching
4254 the first operand) seems wrong, as that discards the
4255 qualification without actually performing a copy. Leaving it
4256 as "volatile X" seems wrong as that will result in the
4257 conditional expression failing altogether, even though,
4258 according to this step, the one operand could be converted to
4259 the type of the other. */
4260 if ((conv2 || conv3)
4261 && CLASS_TYPE_P (arg2_type)
4262 && cp_type_quals (arg2_type) != cp_type_quals (arg3_type))
4263 arg2_type = arg3_type =
4264 cp_build_qualified_type (arg2_type,
4265 cp_type_quals (arg2_type)
4266 | cp_type_quals (arg3_type));
4271 If the second and third operands are lvalues and have the same
4272 type, the result is of that type and is an lvalue. */
4273 if (real_lvalue_p (arg2)
4274 && real_lvalue_p (arg3)
4275 && same_type_p (arg2_type, arg3_type))
4277 result_type = arg2_type;
4278 arg2 = mark_lvalue_use (arg2);
4279 arg3 = mark_lvalue_use (arg3);
4280 goto valid_operands;
4285 Otherwise, the result is an rvalue. If the second and third
4286 operand do not have the same type, and either has (possibly
4287 cv-qualified) class type, overload resolution is used to
4288 determine the conversions (if any) to be applied to the operands
4289 (_over.match.oper_, _over.built_). */
4291 if (!same_type_p (arg2_type, arg3_type)
4292 && (CLASS_TYPE_P (arg2_type) || CLASS_TYPE_P (arg3_type)))
4298 /* Rearrange the arguments so that add_builtin_candidate only has
4299 to know about two args. In build_builtin_candidate, the
4300 arguments are unscrambled. */
4304 add_builtin_candidates (&candidates,
4307 ansi_opname (COND_EXPR),
4313 If the overload resolution fails, the program is
4315 candidates = splice_viable (candidates, pedantic, &any_viable_p);
4318 if (complain & tf_error)
4320 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4321 print_z_candidates (location_of (arg1), candidates);
4323 return error_mark_node;
4325 cand = tourney (candidates);
4328 if (complain & tf_error)
4330 op_error (COND_EXPR, NOP_EXPR, arg1, arg2, arg3, FALSE);
4331 print_z_candidates (location_of (arg1), candidates);
4333 return error_mark_node;
4338 Otherwise, the conversions thus determined are applied, and
4339 the converted operands are used in place of the original
4340 operands for the remainder of this section. */
4341 conv = cand->convs[0];
4342 arg1 = convert_like (conv, arg1, complain);
4343 conv = cand->convs[1];
4344 arg2 = convert_like (conv, arg2, complain);
4345 arg2_type = TREE_TYPE (arg2);
4346 conv = cand->convs[2];
4347 arg3 = convert_like (conv, arg3, complain);
4348 arg3_type = TREE_TYPE (arg3);
4353 Lvalue-to-rvalue (_conv.lval_), array-to-pointer (_conv.array_),
4354 and function-to-pointer (_conv.func_) standard conversions are
4355 performed on the second and third operands.
4357 We need to force the lvalue-to-rvalue conversion here for class types,
4358 so we get TARGET_EXPRs; trying to deal with a COND_EXPR of class rvalues
4359 that isn't wrapped with a TARGET_EXPR plays havoc with exception
4362 arg2 = force_rvalue (arg2);
4363 if (!CLASS_TYPE_P (arg2_type))
4364 arg2_type = TREE_TYPE (arg2);
4366 arg3 = force_rvalue (arg3);
4367 if (!CLASS_TYPE_P (arg3_type))
4368 arg3_type = TREE_TYPE (arg3);
4370 if (arg2 == error_mark_node || arg3 == error_mark_node)
4371 return error_mark_node;
4375 After those conversions, one of the following shall hold:
4377 --The second and third operands have the same type; the result is of
4379 if (same_type_p (arg2_type, arg3_type))
4380 result_type = arg2_type;
4383 --The second and third operands have arithmetic or enumeration
4384 type; the usual arithmetic conversions are performed to bring
4385 them to a common type, and the result is of that type. */
4386 else if ((ARITHMETIC_TYPE_P (arg2_type)
4387 || UNSCOPED_ENUM_P (arg2_type))
4388 && (ARITHMETIC_TYPE_P (arg3_type)
4389 || UNSCOPED_ENUM_P (arg3_type)))
4391 /* In this case, there is always a common type. */
4392 result_type = type_after_usual_arithmetic_conversions (arg2_type,
4394 do_warn_double_promotion (result_type, arg2_type, arg3_type,
4395 "implicit conversion from %qT to %qT to "
4396 "match other result of conditional",
4399 if (TREE_CODE (arg2_type) == ENUMERAL_TYPE
4400 && TREE_CODE (arg3_type) == ENUMERAL_TYPE)
4402 if (complain & tf_warning)
4404 "enumeral mismatch in conditional expression: %qT vs %qT",
4405 arg2_type, arg3_type);
4407 else if (extra_warnings
4408 && ((TREE_CODE (arg2_type) == ENUMERAL_TYPE
4409 && !same_type_p (arg3_type, type_promotes_to (arg2_type)))
4410 || (TREE_CODE (arg3_type) == ENUMERAL_TYPE
4411 && !same_type_p (arg2_type, type_promotes_to (arg3_type)))))
4413 if (complain & tf_warning)
4415 "enumeral and non-enumeral type in conditional expression");
4418 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4419 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4423 --The second and third operands have pointer type, or one has
4424 pointer type and the other is a null pointer constant; pointer
4425 conversions (_conv.ptr_) and qualification conversions
4426 (_conv.qual_) are performed to bring them to their composite
4427 pointer type (_expr.rel_). The result is of the composite
4430 --The second and third operands have pointer to member type, or
4431 one has pointer to member type and the other is a null pointer
4432 constant; pointer to member conversions (_conv.mem_) and
4433 qualification conversions (_conv.qual_) are performed to bring
4434 them to a common type, whose cv-qualification shall match the
4435 cv-qualification of either the second or the third operand.
4436 The result is of the common type. */
4437 else if ((null_ptr_cst_p (arg2)
4438 && (TYPE_PTR_P (arg3_type) || TYPE_PTR_TO_MEMBER_P (arg3_type)))
4439 || (null_ptr_cst_p (arg3)
4440 && (TYPE_PTR_P (arg2_type) || TYPE_PTR_TO_MEMBER_P (arg2_type)))
4441 || (TYPE_PTR_P (arg2_type) && TYPE_PTR_P (arg3_type))
4442 || (TYPE_PTRMEM_P (arg2_type) && TYPE_PTRMEM_P (arg3_type))
4443 || (TYPE_PTRMEMFUNC_P (arg2_type) && TYPE_PTRMEMFUNC_P (arg3_type)))
4445 result_type = composite_pointer_type (arg2_type, arg3_type, arg2,
4446 arg3, CPO_CONDITIONAL_EXPR,
4448 if (result_type == error_mark_node)
4449 return error_mark_node;
4450 arg2 = perform_implicit_conversion (result_type, arg2, complain);
4451 arg3 = perform_implicit_conversion (result_type, arg3, complain);
4456 if (complain & tf_error)
4457 error ("operands to ?: have different types %qT and %qT",
4458 arg2_type, arg3_type);
4459 return error_mark_node;
4463 result = build3 (COND_EXPR, result_type, arg1, arg2, arg3);
4464 if (!cp_unevaluated_operand)
4465 /* Avoid folding within decltype (c++/42013) and noexcept. */
4466 result = fold_if_not_in_template (result);
4468 /* We can't use result_type below, as fold might have returned a
4473 /* Expand both sides into the same slot, hopefully the target of
4474 the ?: expression. We used to check for TARGET_EXPRs here,
4475 but now we sometimes wrap them in NOP_EXPRs so the test would
4477 if (CLASS_TYPE_P (TREE_TYPE (result)))
4478 result = get_target_expr (result);
4479 /* If this expression is an rvalue, but might be mistaken for an
4480 lvalue, we must add a NON_LVALUE_EXPR. */
4481 result = rvalue (result);
4487 /* OPERAND is an operand to an expression. Perform necessary steps
4488 required before using it. If OPERAND is NULL_TREE, NULL_TREE is
4492 prep_operand (tree operand)
4496 if (CLASS_TYPE_P (TREE_TYPE (operand))
4497 && CLASSTYPE_TEMPLATE_INSTANTIATION (TREE_TYPE (operand)))
4498 /* Make sure the template type is instantiated now. */
4499 instantiate_class_template (TYPE_MAIN_VARIANT (TREE_TYPE (operand)));
4505 /* Add each of the viable functions in FNS (a FUNCTION_DECL or
4506 OVERLOAD) to the CANDIDATES, returning an updated list of
4507 CANDIDATES. The ARGS are the arguments provided to the call;
4508 if FIRST_ARG is non-null it is the implicit object argument,
4509 otherwise the first element of ARGS is used if needed. The
4510 EXPLICIT_TARGS are explicit template arguments provided.
4511 TEMPLATE_ONLY is true if only template functions should be
4512 considered. CONVERSION_PATH, ACCESS_PATH, and FLAGS are as for
4513 add_function_candidate. */
4516 add_candidates (tree fns, tree first_arg, const VEC(tree,gc) *args,
4518 tree explicit_targs, bool template_only,
4519 tree conversion_path, tree access_path,
4521 struct z_candidate **candidates)
4524 const VEC(tree,gc) *non_static_args;
4525 bool check_list_ctor;
4526 bool check_converting;
4527 unification_kind_t strict;
4533 /* Precalculate special handling of constructors and conversion ops. */
4534 fn = OVL_CURRENT (fns);
4535 if (DECL_CONV_FN_P (fn))
4537 check_list_ctor = false;
4538 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4539 if (flags & LOOKUP_NO_CONVERSION)
4540 /* We're doing return_type(x). */
4541 strict = DEDUCE_CONV;
4543 /* We're doing x.operator return_type(). */
4544 strict = DEDUCE_EXACT;
4545 /* [over.match.funcs] For conversion functions, the function
4546 is considered to be a member of the class of the implicit
4547 object argument for the purpose of defining the type of
4548 the implicit object parameter. */
4549 ctype = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (first_arg)));
4553 if (DECL_CONSTRUCTOR_P (fn))
4555 check_list_ctor = !!(flags & LOOKUP_LIST_ONLY);
4556 check_converting = !!(flags & LOOKUP_ONLYCONVERTING);
4560 check_list_ctor = false;
4561 check_converting = false;
4563 strict = DEDUCE_CALL;
4564 ctype = conversion_path ? BINFO_TYPE (conversion_path) : NULL_TREE;
4568 non_static_args = args;
4570 /* Delay creating the implicit this parameter until it is needed. */
4571 non_static_args = NULL;
4573 for (; fns; fns = OVL_NEXT (fns))
4576 const VEC(tree,gc) *fn_args;
4578 fn = OVL_CURRENT (fns);
4580 if (check_converting && DECL_NONCONVERTING_P (fn))
4582 if (check_list_ctor && !is_list_ctor (fn))
4585 /* Figure out which set of arguments to use. */
4586 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
4588 /* If this function is a non-static member and we didn't get an
4589 implicit object argument, move it out of args. */
4590 if (first_arg == NULL_TREE)
4594 VEC(tree,gc) *tempvec
4595 = VEC_alloc (tree, gc, VEC_length (tree, args) - 1);
4596 for (ix = 1; VEC_iterate (tree, args, ix, arg); ++ix)
4597 VEC_quick_push (tree, tempvec, arg);
4598 non_static_args = tempvec;
4599 first_arg = build_this (VEC_index (tree, args, 0));
4602 fn_first_arg = first_arg;
4603 fn_args = non_static_args;
4607 /* Otherwise, just use the list of arguments provided. */
4608 fn_first_arg = NULL_TREE;
4612 if (TREE_CODE (fn) == TEMPLATE_DECL)
4613 add_template_candidate (candidates,
4624 else if (!template_only)
4625 add_function_candidate (candidates,
4636 /* Even unsigned enum types promote to signed int. We don't want to
4637 issue -Wsign-compare warnings for this case. Here ORIG_ARG is the
4638 original argument and ARG is the argument after any conversions
4639 have been applied. We set TREE_NO_WARNING if we have added a cast
4640 from an unsigned enum type to a signed integer type. */
4643 avoid_sign_compare_warnings (tree orig_arg, tree arg)
4645 if (orig_arg != NULL_TREE
4648 && TREE_CODE (TREE_TYPE (orig_arg)) == ENUMERAL_TYPE
4649 && TYPE_UNSIGNED (TREE_TYPE (orig_arg))
4650 && INTEGRAL_TYPE_P (TREE_TYPE (arg))
4651 && !TYPE_UNSIGNED (TREE_TYPE (arg)))
4652 TREE_NO_WARNING (arg) = 1;
4656 build_new_op (enum tree_code code, int flags, tree arg1, tree arg2, tree arg3,
4657 bool *overloaded_p, tsubst_flags_t complain)
4659 tree orig_arg1 = arg1;
4660 tree orig_arg2 = arg2;
4661 tree orig_arg3 = arg3;
4662 struct z_candidate *candidates = 0, *cand;
4663 VEC(tree,gc) *arglist;
4666 tree result = NULL_TREE;
4667 bool result_valid_p = false;
4668 enum tree_code code2 = NOP_EXPR;
4669 enum tree_code code_orig_arg1 = ERROR_MARK;
4670 enum tree_code code_orig_arg2 = ERROR_MARK;
4676 if (error_operand_p (arg1)
4677 || error_operand_p (arg2)
4678 || error_operand_p (arg3))
4679 return error_mark_node;
4681 if (code == MODIFY_EXPR)
4683 code2 = TREE_CODE (arg3);
4685 fnname = ansi_assopname (code2);
4688 fnname = ansi_opname (code);
4690 arg1 = prep_operand (arg1);
4696 case VEC_DELETE_EXPR:
4698 /* Use build_op_new_call and build_op_delete_call instead. */
4702 /* Use build_op_call instead. */
4705 case TRUTH_ORIF_EXPR:
4706 case TRUTH_ANDIF_EXPR:
4707 case TRUTH_AND_EXPR:
4709 /* These are saved for the sake of warn_logical_operator. */
4710 code_orig_arg1 = TREE_CODE (arg1);
4711 code_orig_arg2 = TREE_CODE (arg2);
4717 arg2 = prep_operand (arg2);
4718 arg3 = prep_operand (arg3);
4720 if (code == COND_EXPR)
4721 /* Use build_conditional_expr instead. */
4723 else if (! IS_OVERLOAD_TYPE (TREE_TYPE (arg1))
4724 && (! arg2 || ! IS_OVERLOAD_TYPE (TREE_TYPE (arg2))))
4727 if (code == POSTINCREMENT_EXPR || code == POSTDECREMENT_EXPR)
4728 arg2 = integer_zero_node;
4730 arglist = VEC_alloc (tree, gc, 3);
4731 VEC_quick_push (tree, arglist, arg1);
4732 if (arg2 != NULL_TREE)
4733 VEC_quick_push (tree, arglist, arg2);
4734 if (arg3 != NULL_TREE)
4735 VEC_quick_push (tree, arglist, arg3);
4737 /* Get the high-water mark for the CONVERSION_OBSTACK. */
4738 p = conversion_obstack_alloc (0);
4740 /* Add namespace-scope operators to the list of functions to
4742 add_candidates (lookup_function_nonclass (fnname, arglist, /*block_p=*/true),
4743 NULL_TREE, arglist, NULL_TREE,
4744 NULL_TREE, false, NULL_TREE, NULL_TREE,
4745 flags, &candidates);
4746 /* Add class-member operators to the candidate set. */
4747 if (CLASS_TYPE_P (TREE_TYPE (arg1)))
4751 fns = lookup_fnfields (TREE_TYPE (arg1), fnname, 1);
4752 if (fns == error_mark_node)
4754 result = error_mark_node;
4755 goto user_defined_result_ready;
4758 add_candidates (BASELINK_FUNCTIONS (fns),
4759 NULL_TREE, arglist, NULL_TREE,
4761 BASELINK_BINFO (fns),
4762 BASELINK_ACCESS_BINFO (fns),
4763 flags, &candidates);
4768 args[2] = NULL_TREE;
4770 add_builtin_candidates (&candidates, code, code2, fnname, args, flags);
4776 /* For these, the built-in candidates set is empty
4777 [over.match.oper]/3. We don't want non-strict matches
4778 because exact matches are always possible with built-in
4779 operators. The built-in candidate set for COMPONENT_REF
4780 would be empty too, but since there are no such built-in
4781 operators, we accept non-strict matches for them. */
4786 strict_p = pedantic;
4790 candidates = splice_viable (candidates, strict_p, &any_viable_p);
4795 case POSTINCREMENT_EXPR:
4796 case POSTDECREMENT_EXPR:
4797 /* Don't try anything fancy if we're not allowed to produce
4799 if (!(complain & tf_error))
4800 return error_mark_node;
4802 /* Look for an `operator++ (int)'. Pre-1985 C++ didn't
4803 distinguish between prefix and postfix ++ and
4804 operator++() was used for both, so we allow this with
4806 if (flags & LOOKUP_COMPLAIN)
4808 const char *msg = (flag_permissive)
4809 ? G_("no %<%D(int)%> declared for postfix %qs,"
4810 " trying prefix operator instead")
4811 : G_("no %<%D(int)%> declared for postfix %qs");
4812 permerror (input_location, msg, fnname,
4813 operator_name_info[code].name);
4816 if (!flag_permissive)
4817 return error_mark_node;
4819 if (code == POSTINCREMENT_EXPR)
4820 code = PREINCREMENT_EXPR;
4822 code = PREDECREMENT_EXPR;
4823 result = build_new_op (code, flags, arg1, NULL_TREE, NULL_TREE,
4824 overloaded_p, complain);
4827 /* The caller will deal with these. */
4832 result_valid_p = true;
4836 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4838 /* If one of the arguments of the operator represents
4839 an invalid use of member function pointer, try to report
4840 a meaningful error ... */
4841 if (invalid_nonstatic_memfn_p (arg1, tf_error)
4842 || invalid_nonstatic_memfn_p (arg2, tf_error)
4843 || invalid_nonstatic_memfn_p (arg3, tf_error))
4844 /* We displayed the error message. */;
4847 /* ... Otherwise, report the more generic
4848 "no matching operator found" error */
4849 op_error (code, code2, arg1, arg2, arg3, FALSE);
4850 print_z_candidates (input_location, candidates);
4853 result = error_mark_node;
4859 cand = tourney (candidates);
4862 if ((flags & LOOKUP_COMPLAIN) && (complain & tf_error))
4864 op_error (code, code2, arg1, arg2, arg3, TRUE);
4865 print_z_candidates (input_location, candidates);
4867 result = error_mark_node;
4869 else if (TREE_CODE (cand->fn) == FUNCTION_DECL)
4872 *overloaded_p = true;
4874 if (resolve_args (arglist, complain) == NULL)
4875 result = error_mark_node;
4877 result = build_over_call (cand, LOOKUP_NORMAL, complain);
4881 /* Give any warnings we noticed during overload resolution. */
4882 if (cand->warnings && (complain & tf_warning))
4884 struct candidate_warning *w;
4885 for (w = cand->warnings; w; w = w->next)
4886 joust (cand, w->loser, 1);
4889 /* Check for comparison of different enum types. */
4898 if (TREE_CODE (TREE_TYPE (arg1)) == ENUMERAL_TYPE
4899 && TREE_CODE (TREE_TYPE (arg2)) == ENUMERAL_TYPE
4900 && (TYPE_MAIN_VARIANT (TREE_TYPE (arg1))
4901 != TYPE_MAIN_VARIANT (TREE_TYPE (arg2)))
4902 && (complain & tf_warning))
4904 warning (OPT_Wenum_compare,
4905 "comparison between %q#T and %q#T",
4906 TREE_TYPE (arg1), TREE_TYPE (arg2));
4913 /* We need to strip any leading REF_BIND so that bitfields
4914 don't cause errors. This should not remove any important
4915 conversions, because builtins don't apply to class
4916 objects directly. */
4917 conv = cand->convs[0];
4918 if (conv->kind == ck_ref_bind)
4919 conv = conv->u.next;
4920 arg1 = convert_like (conv, arg1, complain);
4924 /* We need to call warn_logical_operator before
4925 converting arg2 to a boolean_type. */
4926 if (complain & tf_warning)
4927 warn_logical_operator (input_location, code, boolean_type_node,
4928 code_orig_arg1, arg1,
4929 code_orig_arg2, arg2);
4931 conv = cand->convs[1];
4932 if (conv->kind == ck_ref_bind)
4933 conv = conv->u.next;
4934 arg2 = convert_like (conv, arg2, complain);
4938 conv = cand->convs[2];
4939 if (conv->kind == ck_ref_bind)
4940 conv = conv->u.next;
4941 arg3 = convert_like (conv, arg3, complain);
4947 user_defined_result_ready:
4949 /* Free all the conversions we allocated. */
4950 obstack_free (&conversion_obstack, p);
4952 if (result || result_valid_p)
4956 avoid_sign_compare_warnings (orig_arg1, arg1);
4957 avoid_sign_compare_warnings (orig_arg2, arg2);
4958 avoid_sign_compare_warnings (orig_arg3, arg3);
4963 return cp_build_modify_expr (arg1, code2, arg2, complain);
4966 return cp_build_indirect_ref (arg1, RO_UNARY_STAR, complain);
4968 case TRUTH_ANDIF_EXPR:
4969 case TRUTH_ORIF_EXPR:
4970 case TRUTH_AND_EXPR:
4972 warn_logical_operator (input_location, code, boolean_type_node,
4973 code_orig_arg1, arg1, code_orig_arg2, arg2);
4978 case TRUNC_DIV_EXPR:
4989 case TRUNC_MOD_EXPR:
4993 return cp_build_binary_op (input_location, code, arg1, arg2, complain);
4995 case UNARY_PLUS_EXPR:
4998 case TRUTH_NOT_EXPR:
4999 case PREINCREMENT_EXPR:
5000 case POSTINCREMENT_EXPR:
5001 case PREDECREMENT_EXPR:
5002 case POSTDECREMENT_EXPR:
5005 return cp_build_unary_op (code, arg1, candidates != 0, complain);
5008 return cp_build_array_ref (input_location, arg1, arg2, complain);
5011 return build_m_component_ref (cp_build_indirect_ref (arg1, RO_NULL,
5015 /* The caller will deal with these. */
5027 /* Returns true iff T, an element of an OVERLOAD chain, is a usual
5028 deallocation function (3.7.4.2 [basic.stc.dynamic.deallocation]). */
5031 non_placement_deallocation_fn_p (tree t)
5033 /* A template instance is never a usual deallocation function,
5034 regardless of its signature. */
5035 if (TREE_CODE (t) == TEMPLATE_DECL
5036 || primary_template_instantiation_p (t))
5039 /* If a class T has a member deallocation function named operator delete
5040 with exactly one parameter, then that function is a usual
5041 (non-placement) deallocation function. If class T does not declare
5042 such an operator delete but does declare a member deallocation
5043 function named operator delete with exactly two parameters, the second
5044 of which has type std::size_t (18.2), then this function is a usual
5045 deallocation function. */
5046 t = FUNCTION_ARG_CHAIN (t);
5047 if (t == void_list_node
5048 || (t && same_type_p (TREE_VALUE (t), size_type_node)
5049 && TREE_CHAIN (t) == void_list_node))
5054 /* Build a call to operator delete. This has to be handled very specially,
5055 because the restrictions on what signatures match are different from all
5056 other call instances. For a normal delete, only a delete taking (void *)
5057 or (void *, size_t) is accepted. For a placement delete, only an exact
5058 match with the placement new is accepted.
5060 CODE is either DELETE_EXPR or VEC_DELETE_EXPR.
5061 ADDR is the pointer to be deleted.
5062 SIZE is the size of the memory block to be deleted.
5063 GLOBAL_P is true if the delete-expression should not consider
5064 class-specific delete operators.
5065 PLACEMENT is the corresponding placement new call, or NULL_TREE.
5067 If this call to "operator delete" is being generated as part to
5068 deallocate memory allocated via a new-expression (as per [expr.new]
5069 which requires that if the initialization throws an exception then
5070 we call a deallocation function), then ALLOC_FN is the allocation
5074 build_op_delete_call (enum tree_code code, tree addr, tree size,
5075 bool global_p, tree placement,
5078 tree fn = NULL_TREE;
5079 tree fns, fnname, type, t;
5081 if (addr == error_mark_node)
5082 return error_mark_node;
5084 type = strip_array_types (TREE_TYPE (TREE_TYPE (addr)));
5086 fnname = ansi_opname (code);
5088 if (CLASS_TYPE_P (type)
5089 && COMPLETE_TYPE_P (complete_type (type))
5093 If the result of the lookup is ambiguous or inaccessible, or if
5094 the lookup selects a placement deallocation function, the
5095 program is ill-formed.
5097 Therefore, we ask lookup_fnfields to complain about ambiguity. */
5099 fns = lookup_fnfields (TYPE_BINFO (type), fnname, 1);
5100 if (fns == error_mark_node)
5101 return error_mark_node;
5106 if (fns == NULL_TREE)
5107 fns = lookup_name_nonclass (fnname);
5109 /* Strip const and volatile from addr. */
5110 addr = cp_convert (ptr_type_node, addr);
5114 /* "A declaration of a placement deallocation function matches the
5115 declaration of a placement allocation function if it has the same
5116 number of parameters and, after parameter transformations (8.3.5),
5117 all parameter types except the first are identical."
5119 So we build up the function type we want and ask instantiate_type
5120 to get it for us. */
5121 t = FUNCTION_ARG_CHAIN (alloc_fn);
5122 t = tree_cons (NULL_TREE, ptr_type_node, t);
5123 t = build_function_type (void_type_node, t);
5125 fn = instantiate_type (t, fns, tf_none);
5126 if (fn == error_mark_node)
5129 if (BASELINK_P (fn))
5130 fn = BASELINK_FUNCTIONS (fn);
5132 /* "If the lookup finds the two-parameter form of a usual deallocation
5133 function (3.7.4.2) and that function, considered as a placement
5134 deallocation function, would have been selected as a match for the
5135 allocation function, the program is ill-formed." */
5136 if (non_placement_deallocation_fn_p (fn))
5138 /* But if the class has an operator delete (void *), then that is
5139 the usual deallocation function, so we shouldn't complain
5140 about using the operator delete (void *, size_t). */
5141 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5142 t; t = OVL_NEXT (t))
5144 tree elt = OVL_CURRENT (t);
5145 if (non_placement_deallocation_fn_p (elt)
5146 && FUNCTION_ARG_CHAIN (elt) == void_list_node)
5149 permerror (0, "non-placement deallocation function %q+D", fn);
5150 permerror (input_location, "selected for placement delete");
5155 /* "Any non-placement deallocation function matches a non-placement
5156 allocation function. If the lookup finds a single matching
5157 deallocation function, that function will be called; otherwise, no
5158 deallocation function will be called." */
5159 for (t = BASELINK_P (fns) ? BASELINK_FUNCTIONS (fns) : fns;
5160 t; t = OVL_NEXT (t))
5162 tree elt = OVL_CURRENT (t);
5163 if (non_placement_deallocation_fn_p (elt))
5166 /* "If a class T has a member deallocation function named
5167 operator delete with exactly one parameter, then that
5168 function is a usual (non-placement) deallocation
5169 function. If class T does not declare such an operator
5170 delete but does declare a member deallocation function named
5171 operator delete with exactly two parameters, the second of
5172 which has type std::size_t (18.2), then this function is a
5173 usual deallocation function."
5175 So (void*) beats (void*, size_t). */
5176 if (FUNCTION_ARG_CHAIN (fn) == void_list_node)
5181 /* If we have a matching function, call it. */
5184 gcc_assert (TREE_CODE (fn) == FUNCTION_DECL);
5186 /* If the FN is a member function, make sure that it is
5188 if (BASELINK_P (fns))
5189 perform_or_defer_access_check (BASELINK_BINFO (fns), fn, fn);
5191 /* Core issue 901: It's ok to new a type with deleted delete. */
5192 if (DECL_DELETED_FN (fn) && alloc_fn)
5197 /* The placement args might not be suitable for overload
5198 resolution at this point, so build the call directly. */
5199 int nargs = call_expr_nargs (placement);
5200 tree *argarray = XALLOCAVEC (tree, nargs);
5203 for (i = 1; i < nargs; i++)
5204 argarray[i] = CALL_EXPR_ARG (placement, i);
5206 return build_cxx_call (fn, nargs, argarray);
5211 VEC(tree,gc) *args = VEC_alloc (tree, gc, 2);
5212 VEC_quick_push (tree, args, addr);
5213 if (FUNCTION_ARG_CHAIN (fn) != void_list_node)
5214 VEC_quick_push (tree, args, size);
5215 ret = cp_build_function_call_vec (fn, &args, tf_warning_or_error);
5216 VEC_free (tree, gc, args);
5223 If no unambiguous matching deallocation function can be found,
5224 propagating the exception does not cause the object's memory to
5229 warning (0, "no corresponding deallocation function for %qD",
5234 error ("no suitable %<operator %s%> for %qT",
5235 operator_name_info[(int)code].name, type);
5236 return error_mark_node;
5239 /* If the current scope isn't allowed to access DECL along
5240 BASETYPE_PATH, give an error. The most derived class in
5241 BASETYPE_PATH is the one used to qualify DECL. DIAG_DECL is
5242 the declaration to use in the error diagnostic. */
5245 enforce_access (tree basetype_path, tree decl, tree diag_decl)
5247 gcc_assert (TREE_CODE (basetype_path) == TREE_BINFO);
5249 if (!accessible_p (basetype_path, decl, true))
5251 if (TREE_PRIVATE (decl))
5252 error ("%q+#D is private", diag_decl);
5253 else if (TREE_PROTECTED (decl))
5254 error ("%q+#D is protected", diag_decl);
5256 error ("%q+#D is inaccessible", diag_decl);
5257 error ("within this context");
5264 /* Initialize a temporary of type TYPE with EXPR. The FLAGS are a
5265 bitwise or of LOOKUP_* values. If any errors are warnings are
5266 generated, set *DIAGNOSTIC_FN to "error" or "warning",
5267 respectively. If no diagnostics are generated, set *DIAGNOSTIC_FN
5271 build_temp (tree expr, tree type, int flags,
5272 diagnostic_t *diagnostic_kind, tsubst_flags_t complain)
5277 savew = warningcount, savee = errorcount;
5278 args = make_tree_vector_single (expr);
5279 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
5280 &args, type, flags, complain);
5281 release_tree_vector (args);
5282 if (warningcount > savew)
5283 *diagnostic_kind = DK_WARNING;
5284 else if (errorcount > savee)
5285 *diagnostic_kind = DK_ERROR;
5287 *diagnostic_kind = DK_UNSPECIFIED;
5291 /* Perform warnings about peculiar, but valid, conversions from/to NULL.
5292 EXPR is implicitly converted to type TOTYPE.
5293 FN and ARGNUM are used for diagnostics. */
5296 conversion_null_warnings (tree totype, tree expr, tree fn, int argnum)
5298 tree t = non_reference (totype);
5300 /* Issue warnings about peculiar, but valid, uses of NULL. */
5301 if (expr == null_node && TREE_CODE (t) != BOOLEAN_TYPE && ARITHMETIC_TYPE_P (t))
5304 warning_at (input_location, OPT_Wconversion_null,
5305 "passing NULL to non-pointer argument %P of %qD",
5308 warning_at (input_location, OPT_Wconversion_null,
5309 "converting to non-pointer type %qT from NULL", t);
5312 /* Issue warnings if "false" is converted to a NULL pointer */
5313 else if (expr == boolean_false_node && fn && POINTER_TYPE_P (t))
5314 warning_at (input_location, OPT_Wconversion_null,
5315 "converting %<false%> to pointer type for argument %P of %qD",
5319 /* Perform the conversions in CONVS on the expression EXPR. FN and
5320 ARGNUM are used for diagnostics. ARGNUM is zero based, -1
5321 indicates the `this' argument of a method. INNER is nonzero when
5322 being called to continue a conversion chain. It is negative when a
5323 reference binding will be applied, positive otherwise. If
5324 ISSUE_CONVERSION_WARNINGS is true, warnings about suspicious
5325 conversions will be emitted if appropriate. If C_CAST_P is true,
5326 this conversion is coming from a C-style cast; in that case,
5327 conversions to inaccessible bases are permitted. */
5330 convert_like_real (conversion *convs, tree expr, tree fn, int argnum,
5331 int inner, bool issue_conversion_warnings,
5332 bool c_cast_p, tsubst_flags_t complain)
5334 tree totype = convs->type;
5335 diagnostic_t diag_kind;
5339 && convs->kind != ck_user
5340 && convs->kind != ck_list
5341 && convs->kind != ck_ambig
5342 && convs->kind != ck_ref_bind
5343 && convs->kind != ck_rvalue
5344 && convs->kind != ck_base)
5346 conversion *t = convs;
5348 /* Give a helpful error if this is bad because of excess braces. */
5349 if (BRACE_ENCLOSED_INITIALIZER_P (expr)
5350 && SCALAR_TYPE_P (totype)
5351 && CONSTRUCTOR_NELTS (expr) > 0
5352 && BRACE_ENCLOSED_INITIALIZER_P (CONSTRUCTOR_ELT (expr, 0)->value))
5353 permerror (input_location, "too many braces around initializer for %qT", totype);
5355 for (; t; t = convs->u.next)
5357 if (t->kind == ck_user || !t->bad_p)
5359 expr = convert_like_real (t, expr, fn, argnum, 1,
5360 /*issue_conversion_warnings=*/false,
5365 else if (t->kind == ck_ambig)
5366 return convert_like_real (t, expr, fn, argnum, 1,
5367 /*issue_conversion_warnings=*/false,
5370 else if (t->kind == ck_identity)
5373 if (complain & tf_error)
5375 permerror (input_location, "invalid conversion from %qT to %qT", TREE_TYPE (expr), totype);
5377 permerror (DECL_SOURCE_LOCATION (fn),
5378 " initializing argument %P of %qD", argnum, fn);
5381 return error_mark_node;
5383 return cp_convert (totype, expr);
5386 if (issue_conversion_warnings && (complain & tf_warning))
5387 conversion_null_warnings (totype, expr, fn, argnum);
5389 switch (convs->kind)
5393 struct z_candidate *cand = convs->cand;
5394 tree convfn = cand->fn;
5397 expr = mark_rvalue_use (expr);
5399 /* When converting from an init list we consider explicit
5400 constructors, but actually trying to call one is an error. */
5401 if (DECL_NONCONVERTING_P (convfn) && DECL_CONSTRUCTOR_P (convfn)
5402 /* Unless we're calling it for value-initialization from an
5403 empty list, since that is handled separately in 8.5.4. */
5404 && cand->num_convs > 0)
5406 if (complain & tf_error)
5407 error ("converting to %qT from initializer list would use "
5408 "explicit constructor %qD", totype, convfn);
5410 return error_mark_node;
5413 /* Set user_conv_p on the argument conversions, so rvalue/base
5414 handling knows not to allow any more UDCs. */
5415 for (i = 0; i < cand->num_convs; ++i)
5416 cand->convs[i]->user_conv_p = true;
5418 expr = build_over_call (cand, LOOKUP_NORMAL, complain);
5420 /* If this is a constructor or a function returning an aggr type,
5421 we need to build up a TARGET_EXPR. */
5422 if (DECL_CONSTRUCTOR_P (convfn))
5424 expr = build_cplus_new (totype, expr, complain);
5426 /* Remember that this was list-initialization. */
5427 if (convs->check_narrowing)
5428 TARGET_EXPR_LIST_INIT_P (expr) = true;
5434 expr = mark_rvalue_use (expr);
5435 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
5437 int nelts = CONSTRUCTOR_NELTS (expr);
5439 expr = build_value_init (totype, tf_warning_or_error);
5440 else if (nelts == 1)
5441 expr = CONSTRUCTOR_ELT (expr, 0)->value;
5446 if (type_unknown_p (expr))
5447 expr = instantiate_type (totype, expr, complain);
5448 /* Convert a constant to its underlying value, unless we are
5449 about to bind it to a reference, in which case we need to
5450 leave it as an lvalue. */
5453 expr = decl_constant_value (expr);
5454 if (expr == null_node && INTEGRAL_OR_UNSCOPED_ENUMERATION_TYPE_P (totype))
5455 /* If __null has been converted to an integer type, we do not
5456 want to warn about uses of EXPR as an integer, rather than
5458 expr = build_int_cst (totype, 0);
5462 if (complain & tf_error)
5464 /* Call build_user_type_conversion again for the error. */
5465 build_user_type_conversion (totype, convs->u.expr, LOOKUP_NORMAL);
5467 error (" initializing argument %P of %q+D", argnum, fn);
5469 return error_mark_node;
5473 /* Conversion to std::initializer_list<T>. */
5474 tree elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (totype), 0);
5475 tree new_ctor = build_constructor (init_list_type_node, NULL);
5476 unsigned len = CONSTRUCTOR_NELTS (expr);
5477 tree array, val, field;
5478 VEC(constructor_elt,gc) *vec = NULL;
5481 /* Convert all the elements. */
5482 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expr), ix, val)
5484 tree sub = convert_like_real (convs->u.list[ix], val, fn, argnum,
5485 1, false, false, complain);
5486 if (sub == error_mark_node)
5488 if (!BRACE_ENCLOSED_INITIALIZER_P (val))
5489 check_narrowing (TREE_TYPE (sub), val);
5490 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (new_ctor), NULL_TREE, sub);
5491 if (!TREE_CONSTANT (sub))
5492 TREE_CONSTANT (new_ctor) = false;
5494 /* Build up the array. */
5495 elttype = cp_build_qualified_type
5496 (elttype, cp_type_quals (elttype) | TYPE_QUAL_CONST);
5497 array = build_array_of_n_type (elttype, len);
5498 array = finish_compound_literal (array, new_ctor, complain);
5500 /* Build up the initializer_list object. */
5501 totype = complete_type (totype);
5502 field = next_initializable_field (TYPE_FIELDS (totype));
5503 CONSTRUCTOR_APPEND_ELT (vec, field, decay_conversion (array));
5504 field = next_initializable_field (DECL_CHAIN (field));
5505 CONSTRUCTOR_APPEND_ELT (vec, field, size_int (len));
5506 new_ctor = build_constructor (totype, vec);
5507 return get_target_expr (new_ctor);
5511 return get_target_expr (digest_init (totype, expr));
5517 expr = convert_like_real (convs->u.next, expr, fn, argnum,
5518 convs->kind == ck_ref_bind ? -1 : 1,
5519 convs->kind == ck_ref_bind ? issue_conversion_warnings : false,
5522 if (expr == error_mark_node)
5523 return error_mark_node;
5525 switch (convs->kind)
5528 expr = decay_conversion (expr);
5529 if (! MAYBE_CLASS_TYPE_P (totype))
5531 /* Else fall through. */
5533 if (convs->kind == ck_base && !convs->need_temporary_p)
5535 /* We are going to bind a reference directly to a base-class
5536 subobject of EXPR. */
5537 /* Build an expression for `*((base*) &expr)'. */
5538 expr = cp_build_addr_expr (expr, complain);
5539 expr = convert_to_base (expr, build_pointer_type (totype),
5540 !c_cast_p, /*nonnull=*/true, complain);
5541 expr = cp_build_indirect_ref (expr, RO_IMPLICIT_CONVERSION, complain);
5545 /* Copy-initialization where the cv-unqualified version of the source
5546 type is the same class as, or a derived class of, the class of the
5547 destination [is treated as direct-initialization]. [dcl.init] */
5548 flags = LOOKUP_NORMAL|LOOKUP_ONLYCONVERTING;
5549 if (convs->user_conv_p)
5550 /* This conversion is being done in the context of a user-defined
5551 conversion (i.e. the second step of copy-initialization), so
5552 don't allow any more. */
5553 flags |= LOOKUP_NO_CONVERSION;
5554 if (convs->rvaluedness_matches_p)
5555 flags |= LOOKUP_PREFER_RVALUE;
5556 if (TREE_CODE (expr) == TARGET_EXPR
5557 && TARGET_EXPR_LIST_INIT_P (expr))
5558 /* Copy-list-initialization doesn't actually involve a copy. */
5560 expr = build_temp (expr, totype, flags, &diag_kind, complain);
5561 if (diag_kind && fn)
5563 if ((complain & tf_error))
5564 emit_diagnostic (diag_kind, DECL_SOURCE_LOCATION (fn), 0,
5565 " initializing argument %P of %qD", argnum, fn);
5566 else if (diag_kind == DK_ERROR)
5567 return error_mark_node;
5569 return build_cplus_new (totype, expr, complain);
5573 tree ref_type = totype;
5575 if (convs->bad_p && TYPE_REF_IS_RVALUE (ref_type)
5576 && real_lvalue_p (expr))
5578 if (complain & tf_error)
5580 error ("cannot bind %qT lvalue to %qT",
5581 TREE_TYPE (expr), totype);
5583 error (" initializing argument %P of %q+D", argnum, fn);
5585 return error_mark_node;
5588 /* If necessary, create a temporary.
5590 VA_ARG_EXPR and CONSTRUCTOR expressions are special cases
5591 that need temporaries, even when their types are reference
5592 compatible with the type of reference being bound, so the
5593 upcoming call to cp_build_addr_expr doesn't fail. */
5594 if (convs->need_temporary_p
5595 || TREE_CODE (expr) == CONSTRUCTOR
5596 || TREE_CODE (expr) == VA_ARG_EXPR)
5598 /* Otherwise, a temporary of type "cv1 T1" is created and
5599 initialized from the initializer expression using the rules
5600 for a non-reference copy-initialization (8.5). */
5602 tree type = TREE_TYPE (ref_type);
5603 cp_lvalue_kind lvalue = real_lvalue_p (expr);
5605 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5606 (type, convs->u.next->type));
5607 if (!CP_TYPE_CONST_NON_VOLATILE_P (type)
5608 && !TYPE_REF_IS_RVALUE (ref_type))
5610 if (complain & tf_error)
5612 /* If the reference is volatile or non-const, we
5613 cannot create a temporary. */
5614 if (lvalue & clk_bitfield)
5615 error ("cannot bind bitfield %qE to %qT",
5617 else if (lvalue & clk_packed)
5618 error ("cannot bind packed field %qE to %qT",
5621 error ("cannot bind rvalue %qE to %qT", expr, ref_type);
5623 return error_mark_node;
5625 /* If the source is a packed field, and we must use a copy
5626 constructor, then building the target expr will require
5627 binding the field to the reference parameter to the
5628 copy constructor, and we'll end up with an infinite
5629 loop. If we can use a bitwise copy, then we'll be
5631 if ((lvalue & clk_packed)
5632 && CLASS_TYPE_P (type)
5633 && type_has_nontrivial_copy_init (type))
5635 if (complain & tf_error)
5636 error ("cannot bind packed field %qE to %qT",
5638 return error_mark_node;
5640 if (lvalue & clk_bitfield)
5642 expr = convert_bitfield_to_declared_type (expr);
5643 expr = fold_convert (type, expr);
5645 expr = build_target_expr_with_type (expr, type);
5648 /* Take the address of the thing to which we will bind the
5650 expr = cp_build_addr_expr (expr, complain);
5651 if (expr == error_mark_node)
5652 return error_mark_node;
5654 /* Convert it to a pointer to the type referred to by the
5655 reference. This will adjust the pointer if a derived to
5656 base conversion is being performed. */
5657 expr = cp_convert (build_pointer_type (TREE_TYPE (ref_type)),
5659 /* Convert the pointer to the desired reference type. */
5660 return build_nop (ref_type, expr);
5664 return decay_conversion (expr);
5667 /* Warn about deprecated conversion if appropriate. */
5668 string_conv_p (totype, expr, 1);
5673 expr = convert_to_base (expr, totype, !c_cast_p,
5674 /*nonnull=*/false, complain);
5675 return build_nop (totype, expr);
5678 return convert_ptrmem (totype, expr, /*allow_inverse_p=*/false,
5679 c_cast_p, complain);
5685 if (convs->check_narrowing)
5686 check_narrowing (totype, expr);
5688 if (issue_conversion_warnings && (complain & tf_warning))
5689 expr = convert_and_check (totype, expr);
5691 expr = convert (totype, expr);
5696 /* ARG is being passed to a varargs function. Perform any conversions
5697 required. Return the converted value. */
5700 convert_arg_to_ellipsis (tree arg)
5706 The lvalue-to-rvalue, array-to-pointer, and function-to-pointer
5707 standard conversions are performed. */
5708 arg = decay_conversion (arg);
5709 arg_type = TREE_TYPE (arg);
5712 If the argument has integral or enumeration type that is subject
5713 to the integral promotions (_conv.prom_), or a floating point
5714 type that is subject to the floating point promotion
5715 (_conv.fpprom_), the value of the argument is converted to the
5716 promoted type before the call. */
5717 if (TREE_CODE (arg_type) == REAL_TYPE
5718 && (TYPE_PRECISION (arg_type)
5719 < TYPE_PRECISION (double_type_node))
5720 && !DECIMAL_FLOAT_MODE_P (TYPE_MODE (arg_type)))
5722 if (warn_double_promotion && !c_inhibit_evaluation_warnings)
5723 warning (OPT_Wdouble_promotion,
5724 "implicit conversion from %qT to %qT when passing "
5725 "argument to function",
5726 arg_type, double_type_node);
5727 arg = convert_to_real (double_type_node, arg);
5729 else if (NULLPTR_TYPE_P (arg_type))
5730 arg = null_pointer_node;
5731 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (arg_type))
5732 arg = perform_integral_promotions (arg);
5734 arg = require_complete_type (arg);
5735 arg_type = TREE_TYPE (arg);
5737 if (arg != error_mark_node
5738 /* In a template (or ill-formed code), we can have an incomplete type
5739 even after require_complete_type, in which case we don't know
5740 whether it has trivial copy or not. */
5741 && COMPLETE_TYPE_P (arg_type)
5742 && (type_has_nontrivial_copy_init (arg_type)
5743 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (arg_type)))
5745 /* [expr.call] 5.2.2/7:
5746 Passing a potentially-evaluated argument of class type (Clause 9)
5747 with a non-trivial copy constructor or a non-trivial destructor
5748 with no corresponding parameter is conditionally-supported, with
5749 implementation-defined semantics.
5751 We used to just warn here and do a bitwise copy, but now
5752 cp_expr_size will abort if we try to do that.
5754 If the call appears in the context of a sizeof expression,
5755 it is not potentially-evaluated. */
5756 if (cp_unevaluated_operand == 0)
5757 error ("cannot pass objects of non-trivially-copyable "
5758 "type %q#T through %<...%>", arg_type);
5764 /* va_arg (EXPR, TYPE) is a builtin. Make sure it is not abused. */
5767 build_x_va_arg (tree expr, tree type)
5769 if (processing_template_decl)
5770 return build_min (VA_ARG_EXPR, type, expr);
5772 type = complete_type_or_else (type, NULL_TREE);
5774 if (expr == error_mark_node || !type)
5775 return error_mark_node;
5777 expr = mark_lvalue_use (expr);
5779 if (type_has_nontrivial_copy_init (type)
5780 || TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type)
5781 || TREE_CODE (type) == REFERENCE_TYPE)
5783 /* Remove reference types so we don't ICE later on. */
5784 tree type1 = non_reference (type);
5785 /* conditionally-supported behavior [expr.call] 5.2.2/7. */
5786 error ("cannot receive objects of non-trivially-copyable type %q#T "
5787 "through %<...%>; ", type);
5788 expr = convert (build_pointer_type (type1), null_node);
5789 expr = cp_build_indirect_ref (expr, RO_NULL, tf_warning_or_error);
5793 return build_va_arg (input_location, expr, type);
5796 /* TYPE has been given to va_arg. Apply the default conversions which
5797 would have happened when passed via ellipsis. Return the promoted
5798 type, or the passed type if there is no change. */
5801 cxx_type_promotes_to (tree type)
5805 /* Perform the array-to-pointer and function-to-pointer
5807 type = type_decays_to (type);
5809 promote = type_promotes_to (type);
5810 if (same_type_p (type, promote))
5816 /* ARG is a default argument expression being passed to a parameter of
5817 the indicated TYPE, which is a parameter to FN. PARMNUM is the
5818 zero-based argument number. Do any required conversions. Return
5819 the converted value. */
5821 static GTY(()) VEC(tree,gc) *default_arg_context;
5823 push_defarg_context (tree fn)
5824 { VEC_safe_push (tree, gc, default_arg_context, fn); }
5826 pop_defarg_context (void)
5827 { VEC_pop (tree, default_arg_context); }
5830 convert_default_arg (tree type, tree arg, tree fn, int parmnum)
5835 /* See through clones. */
5836 fn = DECL_ORIGIN (fn);
5838 /* Detect recursion. */
5839 FOR_EACH_VEC_ELT (tree, default_arg_context, i, t)
5842 error ("recursive evaluation of default argument for %q#D", fn);
5843 return error_mark_node;
5846 /* If the ARG is an unparsed default argument expression, the
5847 conversion cannot be performed. */
5848 if (TREE_CODE (arg) == DEFAULT_ARG)
5850 error ("call to %qD uses the default argument for parameter %P, which "
5851 "is not yet defined", fn, parmnum);
5852 return error_mark_node;
5855 push_defarg_context (fn);
5857 if (fn && DECL_TEMPLATE_INFO (fn))
5858 arg = tsubst_default_argument (fn, type, arg);
5864 The names in the expression are bound, and the semantic
5865 constraints are checked, at the point where the default
5866 expressions appears.
5868 we must not perform access checks here. */
5869 push_deferring_access_checks (dk_no_check);
5870 arg = break_out_target_exprs (arg);
5871 if (TREE_CODE (arg) == CONSTRUCTOR)
5873 arg = digest_init (type, arg);
5874 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5875 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5876 tf_warning_or_error);
5880 /* We must make a copy of ARG, in case subsequent processing
5881 alters any part of it. For example, during gimplification a
5882 cast of the form (T) &X::f (where "f" is a member function)
5883 will lead to replacing the PTRMEM_CST for &X::f with a
5884 VAR_DECL. We can avoid the copy for constants, since they
5885 are never modified in place. */
5886 if (!CONSTANT_CLASS_P (arg))
5887 arg = unshare_expr (arg);
5888 arg = convert_for_initialization (0, type, arg, LOOKUP_IMPLICIT,
5889 ICR_DEFAULT_ARGUMENT, fn, parmnum,
5890 tf_warning_or_error);
5891 arg = convert_for_arg_passing (type, arg);
5893 pop_deferring_access_checks();
5895 pop_defarg_context ();
5900 /* Returns the type which will really be used for passing an argument of
5904 type_passed_as (tree type)
5906 /* Pass classes with copy ctors by invisible reference. */
5907 if (TREE_ADDRESSABLE (type))
5909 type = build_reference_type (type);
5910 /* There are no other pointers to this temporary. */
5911 type = cp_build_qualified_type (type, TYPE_QUAL_RESTRICT);
5913 else if (targetm.calls.promote_prototypes (type)
5914 && INTEGRAL_TYPE_P (type)
5915 && COMPLETE_TYPE_P (type)
5916 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5917 TYPE_SIZE (integer_type_node)))
5918 type = integer_type_node;
5923 /* Actually perform the appropriate conversion. */
5926 convert_for_arg_passing (tree type, tree val)
5930 /* If VAL is a bitfield, then -- since it has already been converted
5931 to TYPE -- it cannot have a precision greater than TYPE.
5933 If it has a smaller precision, we must widen it here. For
5934 example, passing "int f:3;" to a function expecting an "int" will
5935 not result in any conversion before this point.
5937 If the precision is the same we must not risk widening. For
5938 example, the COMPONENT_REF for a 32-bit "long long" bitfield will
5939 often have type "int", even though the C++ type for the field is
5940 "long long". If the value is being passed to a function
5941 expecting an "int", then no conversions will be required. But,
5942 if we call convert_bitfield_to_declared_type, the bitfield will
5943 be converted to "long long". */
5944 bitfield_type = is_bitfield_expr_with_lowered_type (val);
5946 && TYPE_PRECISION (TREE_TYPE (val)) < TYPE_PRECISION (type))
5947 val = convert_to_integer (TYPE_MAIN_VARIANT (bitfield_type), val);
5949 if (val == error_mark_node)
5951 /* Pass classes with copy ctors by invisible reference. */
5952 else if (TREE_ADDRESSABLE (type))
5953 val = build1 (ADDR_EXPR, build_reference_type (type), val);
5954 else if (targetm.calls.promote_prototypes (type)
5955 && INTEGRAL_TYPE_P (type)
5956 && COMPLETE_TYPE_P (type)
5957 && INT_CST_LT_UNSIGNED (TYPE_SIZE (type),
5958 TYPE_SIZE (integer_type_node)))
5959 val = perform_integral_promotions (val);
5960 if (warn_missing_format_attribute)
5962 tree rhstype = TREE_TYPE (val);
5963 const enum tree_code coder = TREE_CODE (rhstype);
5964 const enum tree_code codel = TREE_CODE (type);
5965 if ((codel == POINTER_TYPE || codel == REFERENCE_TYPE)
5967 && check_missing_format_attribute (type, rhstype))
5968 warning (OPT_Wmissing_format_attribute,
5969 "argument of function call might be a candidate for a format attribute");
5974 /* Returns true iff FN is a function with magic varargs, i.e. ones for
5975 which no conversions at all should be done. This is true for some
5976 builtins which don't act like normal functions. */
5979 magic_varargs_p (tree fn)
5981 if (DECL_BUILT_IN (fn))
5982 switch (DECL_FUNCTION_CODE (fn))
5984 case BUILT_IN_CLASSIFY_TYPE:
5985 case BUILT_IN_CONSTANT_P:
5986 case BUILT_IN_NEXT_ARG:
5987 case BUILT_IN_VA_START:
5991 return lookup_attribute ("type generic",
5992 TYPE_ATTRIBUTES (TREE_TYPE (fn))) != 0;
5998 /* Subroutine of the various build_*_call functions. Overload resolution
5999 has chosen a winning candidate CAND; build up a CALL_EXPR accordingly.
6000 ARGS is a TREE_LIST of the unconverted arguments to the call. FLAGS is a
6001 bitmask of various LOOKUP_* flags which apply to the call itself. */
6004 build_over_call (struct z_candidate *cand, int flags, tsubst_flags_t complain)
6007 const VEC(tree,gc) *args = cand->args;
6008 tree first_arg = cand->first_arg;
6009 conversion **convs = cand->convs;
6011 tree parm = TYPE_ARG_TYPES (TREE_TYPE (fn));
6016 unsigned int arg_index = 0;
6020 bool already_used = false;
6022 /* In a template, there is no need to perform all of the work that
6023 is normally done. We are only interested in the type of the call
6024 expression, i.e., the return type of the function. Any semantic
6025 errors will be deferred until the template is instantiated. */
6026 if (processing_template_decl)
6030 const tree *argarray;
6033 return_type = TREE_TYPE (TREE_TYPE (fn));
6034 nargs = VEC_length (tree, args);
6035 if (first_arg == NULL_TREE)
6036 argarray = VEC_address (tree, CONST_CAST (VEC(tree,gc) *, args));
6044 alcarray = XALLOCAVEC (tree, nargs);
6045 alcarray[0] = first_arg;
6046 FOR_EACH_VEC_ELT (tree, args, ix, arg)
6047 alcarray[ix + 1] = arg;
6048 argarray = alcarray;
6050 expr = build_call_array_loc (input_location,
6051 return_type, build_addr_func (fn), nargs,
6053 if (TREE_THIS_VOLATILE (fn) && cfun)
6054 current_function_returns_abnormally = 1;
6055 return convert_from_reference (expr);
6058 /* Give any warnings we noticed during overload resolution. */
6059 if (cand->warnings && (complain & tf_warning))
6061 struct candidate_warning *w;
6062 for (w = cand->warnings; w; w = w->next)
6063 joust (cand, w->loser, 1);
6066 /* Make =delete work with SFINAE. */
6067 if (DECL_DELETED_FN (fn) && !(complain & tf_error))
6068 return error_mark_node;
6070 if (DECL_FUNCTION_MEMBER_P (fn))
6073 /* If FN is a template function, two cases must be considered.
6078 template <class T> void f();
6080 template <class T> struct B {
6084 struct C : A, B<int> {
6086 using B<int>::g; // #2
6089 In case #1 where `A::f' is a member template, DECL_ACCESS is
6090 recorded in the primary template but not in its specialization.
6091 We check access of FN using its primary template.
6093 In case #2, where `B<int>::g' has a DECL_TEMPLATE_INFO simply
6094 because it is a member of class template B, DECL_ACCESS is
6095 recorded in the specialization `B<int>::g'. We cannot use its
6096 primary template because `B<T>::g' and `B<int>::g' may have
6097 different access. */
6098 if (DECL_TEMPLATE_INFO (fn)
6099 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (fn)))
6100 access_fn = DECL_TI_TEMPLATE (fn);
6103 if (flags & LOOKUP_SPECULATIVE)
6105 if (!speculative_access_check (cand->access_path, access_fn, fn,
6106 !!(flags & LOOKUP_COMPLAIN)))
6107 return error_mark_node;
6110 perform_or_defer_access_check (cand->access_path, access_fn, fn);
6113 /* If we're checking for implicit delete, don't bother with argument
6115 if (flags & LOOKUP_SPECULATIVE)
6117 if (DECL_DELETED_FN (fn))
6119 if (flags & LOOKUP_COMPLAIN)
6121 return error_mark_node;
6123 if (cand->viable == 1)
6125 else if (!(flags & LOOKUP_COMPLAIN))
6126 /* Reject bad conversions now. */
6127 return error_mark_node;
6128 /* else continue to get conversion error. */
6131 /* Find maximum size of vector to hold converted arguments. */
6132 parmlen = list_length (parm);
6133 nargs = VEC_length (tree, args) + (first_arg != NULL_TREE ? 1 : 0);
6134 if (parmlen > nargs)
6136 argarray = XALLOCAVEC (tree, nargs);
6138 /* The implicit parameters to a constructor are not considered by overload
6139 resolution, and must be of the proper type. */
6140 if (DECL_CONSTRUCTOR_P (fn))
6142 if (first_arg != NULL_TREE)
6144 argarray[j++] = first_arg;
6145 first_arg = NULL_TREE;
6149 argarray[j++] = VEC_index (tree, args, arg_index);
6152 parm = TREE_CHAIN (parm);
6153 /* We should never try to call the abstract constructor. */
6154 gcc_assert (!DECL_HAS_IN_CHARGE_PARM_P (fn));
6156 if (DECL_HAS_VTT_PARM_P (fn))
6158 argarray[j++] = VEC_index (tree, args, arg_index);
6160 parm = TREE_CHAIN (parm);
6163 /* Bypass access control for 'this' parameter. */
6164 else if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE)
6166 tree parmtype = TREE_VALUE (parm);
6167 tree arg = (first_arg != NULL_TREE
6169 : VEC_index (tree, args, arg_index));
6170 tree argtype = TREE_TYPE (arg);
6174 if (convs[i]->bad_p)
6176 if (complain & tf_error)
6177 permerror (input_location, "passing %qT as %<this%> argument of %q#D discards qualifiers",
6178 TREE_TYPE (argtype), fn);
6180 return error_mark_node;
6183 /* [class.mfct.nonstatic]: If a nonstatic member function of a class
6184 X is called for an object that is not of type X, or of a type
6185 derived from X, the behavior is undefined.
6187 So we can assume that anything passed as 'this' is non-null, and
6188 optimize accordingly. */
6189 gcc_assert (TREE_CODE (parmtype) == POINTER_TYPE);
6190 /* Convert to the base in which the function was declared. */
6191 gcc_assert (cand->conversion_path != NULL_TREE);
6192 converted_arg = build_base_path (PLUS_EXPR,
6194 cand->conversion_path,
6196 /* Check that the base class is accessible. */
6197 if (!accessible_base_p (TREE_TYPE (argtype),
6198 BINFO_TYPE (cand->conversion_path), true))
6199 error ("%qT is not an accessible base of %qT",
6200 BINFO_TYPE (cand->conversion_path),
6201 TREE_TYPE (argtype));
6202 /* If fn was found by a using declaration, the conversion path
6203 will be to the derived class, not the base declaring fn. We
6204 must convert from derived to base. */
6205 base_binfo = lookup_base (TREE_TYPE (TREE_TYPE (converted_arg)),
6206 TREE_TYPE (parmtype), ba_unique, NULL);
6207 converted_arg = build_base_path (PLUS_EXPR, converted_arg,
6210 argarray[j++] = converted_arg;
6211 parm = TREE_CHAIN (parm);
6212 if (first_arg != NULL_TREE)
6213 first_arg = NULL_TREE;
6220 gcc_assert (first_arg == NULL_TREE);
6221 for (; arg_index < VEC_length (tree, args) && parm;
6222 parm = TREE_CHAIN (parm), ++arg_index, ++i)
6224 tree type = TREE_VALUE (parm);
6225 tree arg = VEC_index (tree, args, arg_index);
6229 /* Warn about initializer_list deduction that isn't currently in the
6231 if (cxx_dialect > cxx98
6232 && flag_deduce_init_list
6233 && cand->template_decl
6234 && is_std_init_list (non_reference (type))
6235 && BRACE_ENCLOSED_INITIALIZER_P (arg))
6237 tree tmpl = TI_TEMPLATE (cand->template_decl);
6238 tree realparm = chain_index (j, DECL_ARGUMENTS (cand->fn));
6239 tree patparm = get_pattern_parm (realparm, tmpl);
6240 tree pattype = TREE_TYPE (patparm);
6241 if (PACK_EXPANSION_P (pattype))
6242 pattype = PACK_EXPANSION_PATTERN (pattype);
6243 pattype = non_reference (pattype);
6245 if (TREE_CODE (pattype) == TEMPLATE_TYPE_PARM
6246 && (cand->explicit_targs == NULL_TREE
6247 || (TREE_VEC_LENGTH (cand->explicit_targs)
6248 <= TEMPLATE_TYPE_IDX (pattype))))
6250 pedwarn (input_location, 0, "deducing %qT as %qT",
6251 non_reference (TREE_TYPE (patparm)),
6252 non_reference (type));
6253 pedwarn (input_location, 0, " in call to %q+D", cand->fn);
6254 pedwarn (input_location, 0,
6255 " (you can disable this with -fno-deduce-init-list)");
6259 val = convert_like_with_context (conv, arg, fn, i-is_method, complain);
6261 val = convert_for_arg_passing (type, val);
6262 if (val == error_mark_node)
6263 return error_mark_node;
6265 argarray[j++] = val;
6268 /* Default arguments */
6269 for (; parm && parm != void_list_node; parm = TREE_CHAIN (parm), i++)
6270 argarray[j++] = convert_default_arg (TREE_VALUE (parm),
6271 TREE_PURPOSE (parm),
6274 for (; arg_index < VEC_length (tree, args); ++arg_index)
6276 tree a = VEC_index (tree, args, arg_index);
6277 if (magic_varargs_p (fn))
6278 /* Do no conversions for magic varargs. */
6279 a = mark_type_use (a);
6281 a = convert_arg_to_ellipsis (a);
6285 gcc_assert (j <= nargs);
6288 check_function_arguments (TYPE_ATTRIBUTES (TREE_TYPE (fn)),
6289 nargs, argarray, TYPE_ARG_TYPES (TREE_TYPE (fn)));
6291 /* Avoid actually calling copy constructors and copy assignment operators,
6294 if (! flag_elide_constructors)
6295 /* Do things the hard way. */;
6296 else if (cand->num_convs == 1
6297 && (DECL_COPY_CONSTRUCTOR_P (fn)
6298 || DECL_MOVE_CONSTRUCTOR_P (fn)))
6301 tree arg = argarray[num_artificial_parms_for (fn)];
6303 bool trivial = trivial_fn_p (fn);
6305 /* Pull out the real argument, disregarding const-correctness. */
6307 while (CONVERT_EXPR_P (targ)
6308 || TREE_CODE (targ) == NON_LVALUE_EXPR)
6309 targ = TREE_OPERAND (targ, 0);
6310 if (TREE_CODE (targ) == ADDR_EXPR)
6312 targ = TREE_OPERAND (targ, 0);
6313 if (!same_type_ignoring_top_level_qualifiers_p
6314 (TREE_TYPE (TREE_TYPE (arg)), TREE_TYPE (targ)))
6323 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6325 /* [class.copy]: the copy constructor is implicitly defined even if
6326 the implementation elided its use. */
6327 if (!trivial || DECL_DELETED_FN (fn))
6330 already_used = true;
6333 /* If we're creating a temp and we already have one, don't create a
6334 new one. If we're not creating a temp but we get one, use
6335 INIT_EXPR to collapse the temp into our target. Otherwise, if the
6336 ctor is trivial, do a bitwise copy with a simple TARGET_EXPR for a
6337 temp or an INIT_EXPR otherwise. */
6339 if (integer_zerop (fa))
6341 if (TREE_CODE (arg) == TARGET_EXPR)
6344 return force_target_expr (DECL_CONTEXT (fn), arg);
6346 else if (TREE_CODE (arg) == TARGET_EXPR || trivial)
6348 tree to = stabilize_reference (cp_build_indirect_ref (fa, RO_NULL,
6351 val = build2 (INIT_EXPR, DECL_CONTEXT (fn), to, arg);
6355 else if (DECL_OVERLOADED_OPERATOR_P (fn) == NOP_EXPR
6356 && trivial_fn_p (fn)
6357 && !DECL_DELETED_FN (fn))
6359 tree to = stabilize_reference
6360 (cp_build_indirect_ref (argarray[0], RO_NULL, complain));
6361 tree type = TREE_TYPE (to);
6362 tree as_base = CLASSTYPE_AS_BASE (type);
6363 tree arg = argarray[1];
6365 if (is_really_empty_class (type))
6367 /* Avoid copying empty classes. */
6368 val = build2 (COMPOUND_EXPR, void_type_node, to, arg);
6369 TREE_NO_WARNING (val) = 1;
6370 val = build2 (COMPOUND_EXPR, type, val, to);
6371 TREE_NO_WARNING (val) = 1;
6373 else if (tree_int_cst_equal (TYPE_SIZE (type), TYPE_SIZE (as_base)))
6375 arg = cp_build_indirect_ref (arg, RO_NULL, complain);
6376 val = build2 (MODIFY_EXPR, TREE_TYPE (to), to, arg);
6380 /* We must only copy the non-tail padding parts.
6381 Use __builtin_memcpy for the bitwise copy.
6382 FIXME fix 22488 so we can go back to using MODIFY_EXPR
6383 instead of an explicit call to memcpy. */
6385 tree arg0, arg1, arg2, t;
6386 tree test = NULL_TREE;
6388 arg2 = TYPE_SIZE_UNIT (as_base);
6390 arg0 = cp_build_addr_expr (to, complain);
6392 if (!can_trust_pointer_alignment ())
6394 /* If we can't be sure about pointer alignment, a call
6395 to __builtin_memcpy is expanded as a call to memcpy, which
6396 is invalid with identical args. Otherwise it is
6397 expanded as a block move, which should be safe. */
6398 arg0 = save_expr (arg0);
6399 arg1 = save_expr (arg1);
6400 test = build2 (EQ_EXPR, boolean_type_node, arg0, arg1);
6402 t = implicit_built_in_decls[BUILT_IN_MEMCPY];
6403 t = build_call_n (t, 3, arg0, arg1, arg2);
6405 t = convert (TREE_TYPE (arg0), t);
6407 t = build3 (COND_EXPR, TREE_TYPE (t), test, arg0, t);
6408 val = cp_build_indirect_ref (t, RO_NULL, complain);
6409 TREE_NO_WARNING (val) = 1;
6414 /* FIXME handle trivial default constructor and destructor, too. */
6419 if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0)
6422 tree binfo = lookup_base (TREE_TYPE (TREE_TYPE (argarray[0])),
6425 gcc_assert (binfo && binfo != error_mark_node);
6427 /* Warn about deprecated virtual functions now, since we're about
6428 to throw away the decl. */
6429 if (TREE_DEPRECATED (fn))
6430 warn_deprecated_use (fn, NULL_TREE);
6432 argarray[0] = build_base_path (PLUS_EXPR, argarray[0], binfo, 1);
6433 if (TREE_SIDE_EFFECTS (argarray[0]))
6434 argarray[0] = save_expr (argarray[0]);
6435 t = build_pointer_type (TREE_TYPE (fn));
6436 if (DECL_CONTEXT (fn) && TYPE_JAVA_INTERFACE (DECL_CONTEXT (fn)))
6437 fn = build_java_interface_fn_ref (fn, argarray[0]);
6439 fn = build_vfn_ref (argarray[0], DECL_VINDEX (fn));
6443 fn = build_addr_func (fn);
6445 return build_cxx_call (fn, nargs, argarray);
6448 /* Build and return a call to FN, using NARGS arguments in ARGARRAY.
6449 This function performs no overload resolution, conversion, or other
6450 high-level operations. */
6453 build_cxx_call (tree fn, int nargs, tree *argarray)
6457 fn = build_call_a (fn, nargs, argarray);
6459 /* If this call might throw an exception, note that fact. */
6460 fndecl = get_callee_fndecl (fn);
6461 if ((!fndecl || !TREE_NOTHROW (fndecl))
6462 && at_function_scope_p ()
6464 && cp_function_chain)
6465 cp_function_chain->can_throw = 1;
6467 /* Check that arguments to builtin functions match the expectations. */
6469 && DECL_BUILT_IN (fndecl)
6470 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
6471 && !check_builtin_function_arguments (fndecl, nargs, argarray))
6472 return error_mark_node;
6474 /* Some built-in function calls will be evaluated at compile-time in
6476 fn = fold_if_not_in_template (fn);
6478 if (VOID_TYPE_P (TREE_TYPE (fn)))
6481 fn = require_complete_type (fn);
6482 if (fn == error_mark_node)
6483 return error_mark_node;
6485 if (MAYBE_CLASS_TYPE_P (TREE_TYPE (fn)))
6486 fn = build_cplus_new (TREE_TYPE (fn), fn, tf_warning_or_error);
6487 return convert_from_reference (fn);
6490 static GTY(()) tree java_iface_lookup_fn;
6492 /* Make an expression which yields the address of the Java interface
6493 method FN. This is achieved by generating a call to libjava's
6494 _Jv_LookupInterfaceMethodIdx(). */
6497 build_java_interface_fn_ref (tree fn, tree instance)
6499 tree lookup_fn, method, idx;
6500 tree klass_ref, iface, iface_ref;
6503 if (!java_iface_lookup_fn)
6505 tree ftype = build_function_type_list (ptr_type_node,
6506 ptr_type_node, ptr_type_node,
6507 java_int_type_node, NULL_TREE);
6508 java_iface_lookup_fn
6509 = add_builtin_function ("_Jv_LookupInterfaceMethodIdx", ftype,
6510 0, NOT_BUILT_IN, NULL, NULL_TREE);
6513 /* Look up the pointer to the runtime java.lang.Class object for `instance'.
6514 This is the first entry in the vtable. */
6515 klass_ref = build_vtbl_ref (cp_build_indirect_ref (instance, RO_NULL,
6516 tf_warning_or_error),
6519 /* Get the java.lang.Class pointer for the interface being called. */
6520 iface = DECL_CONTEXT (fn);
6521 iface_ref = lookup_field (iface, get_identifier ("class$"), 0, false);
6522 if (!iface_ref || TREE_CODE (iface_ref) != VAR_DECL
6523 || DECL_CONTEXT (iface_ref) != iface)
6525 error ("could not find class$ field in java interface type %qT",
6527 return error_mark_node;
6529 iface_ref = build_address (iface_ref);
6530 iface_ref = convert (build_pointer_type (iface), iface_ref);
6532 /* Determine the itable index of FN. */
6534 for (method = TYPE_METHODS (iface); method; method = DECL_CHAIN (method))
6536 if (!DECL_VIRTUAL_P (method))
6542 idx = build_int_cst (NULL_TREE, i);
6544 lookup_fn = build1 (ADDR_EXPR,
6545 build_pointer_type (TREE_TYPE (java_iface_lookup_fn)),
6546 java_iface_lookup_fn);
6547 return build_call_nary (ptr_type_node, lookup_fn,
6548 3, klass_ref, iface_ref, idx);
6551 /* Returns the value to use for the in-charge parameter when making a
6552 call to a function with the indicated NAME.
6554 FIXME:Can't we find a neater way to do this mapping? */
6557 in_charge_arg_for_name (tree name)
6559 if (name == base_ctor_identifier
6560 || name == base_dtor_identifier)
6561 return integer_zero_node;
6562 else if (name == complete_ctor_identifier)
6563 return integer_one_node;
6564 else if (name == complete_dtor_identifier)
6565 return integer_two_node;
6566 else if (name == deleting_dtor_identifier)
6567 return integer_three_node;
6569 /* This function should only be called with one of the names listed
6575 /* Build a call to a constructor, destructor, or an assignment
6576 operator for INSTANCE, an expression with class type. NAME
6577 indicates the special member function to call; *ARGS are the
6578 arguments. ARGS may be NULL. This may change ARGS. BINFO
6579 indicates the base of INSTANCE that is to be passed as the `this'
6580 parameter to the member function called.
6582 FLAGS are the LOOKUP_* flags to use when processing the call.
6584 If NAME indicates a complete object constructor, INSTANCE may be
6585 NULL_TREE. In this case, the caller will call build_cplus_new to
6586 store the newly constructed object into a VAR_DECL. */
6589 build_special_member_call (tree instance, tree name, VEC(tree,gc) **args,
6590 tree binfo, int flags, tsubst_flags_t complain)
6593 /* The type of the subobject to be constructed or destroyed. */
6595 VEC(tree,gc) *allocated = NULL;
6598 gcc_assert (name == complete_ctor_identifier
6599 || name == base_ctor_identifier
6600 || name == complete_dtor_identifier
6601 || name == base_dtor_identifier
6602 || name == deleting_dtor_identifier
6603 || name == ansi_assopname (NOP_EXPR));
6606 /* Resolve the name. */
6607 if (!complete_type_or_maybe_complain (binfo, NULL_TREE, complain))
6608 return error_mark_node;
6610 binfo = TYPE_BINFO (binfo);
6613 gcc_assert (binfo != NULL_TREE);
6615 class_type = BINFO_TYPE (binfo);
6617 /* Handle the special case where INSTANCE is NULL_TREE. */
6618 if (name == complete_ctor_identifier && !instance)
6620 instance = build_int_cst (build_pointer_type (class_type), 0);
6621 instance = build1 (INDIRECT_REF, class_type, instance);
6625 if (name == complete_dtor_identifier
6626 || name == base_dtor_identifier
6627 || name == deleting_dtor_identifier)
6628 gcc_assert (args == NULL || VEC_empty (tree, *args));
6630 /* Convert to the base class, if necessary. */
6631 if (!same_type_ignoring_top_level_qualifiers_p
6632 (TREE_TYPE (instance), BINFO_TYPE (binfo)))
6634 if (name != ansi_assopname (NOP_EXPR))
6635 /* For constructors and destructors, either the base is
6636 non-virtual, or it is virtual but we are doing the
6637 conversion from a constructor or destructor for the
6638 complete object. In either case, we can convert
6640 instance = convert_to_base_statically (instance, binfo);
6642 /* However, for assignment operators, we must convert
6643 dynamically if the base is virtual. */
6644 instance = build_base_path (PLUS_EXPR, instance,
6645 binfo, /*nonnull=*/1);
6649 gcc_assert (instance != NULL_TREE);
6651 fns = lookup_fnfields (binfo, name, 1);
6653 /* When making a call to a constructor or destructor for a subobject
6654 that uses virtual base classes, pass down a pointer to a VTT for
6656 if ((name == base_ctor_identifier
6657 || name == base_dtor_identifier)
6658 && CLASSTYPE_VBASECLASSES (class_type))
6663 /* If the current function is a complete object constructor
6664 or destructor, then we fetch the VTT directly.
6665 Otherwise, we look it up using the VTT we were given. */
6666 vtt = DECL_CHAIN (CLASSTYPE_VTABLES (current_class_type));
6667 vtt = decay_conversion (vtt);
6668 vtt = build3 (COND_EXPR, TREE_TYPE (vtt),
6669 build2 (EQ_EXPR, boolean_type_node,
6670 current_in_charge_parm, integer_zero_node),
6673 gcc_assert (BINFO_SUBVTT_INDEX (binfo));
6674 sub_vtt = build2 (POINTER_PLUS_EXPR, TREE_TYPE (vtt), vtt,
6675 BINFO_SUBVTT_INDEX (binfo));
6679 allocated = make_tree_vector ();
6683 VEC_safe_insert (tree, gc, *args, 0, sub_vtt);
6686 ret = build_new_method_call (instance, fns, args,
6687 TYPE_BINFO (BINFO_TYPE (binfo)),
6691 if (allocated != NULL)
6692 release_tree_vector (allocated);
6697 /* Return the NAME, as a C string. The NAME indicates a function that
6698 is a member of TYPE. *FREE_P is set to true if the caller must
6699 free the memory returned.
6701 Rather than go through all of this, we should simply set the names
6702 of constructors and destructors appropriately, and dispense with
6703 ctor_identifier, dtor_identifier, etc. */
6706 name_as_c_string (tree name, tree type, bool *free_p)
6710 /* Assume that we will not allocate memory. */
6712 /* Constructors and destructors are special. */
6713 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6716 = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (constructor_name (type))));
6717 /* For a destructor, add the '~'. */
6718 if (name == complete_dtor_identifier
6719 || name == base_dtor_identifier
6720 || name == deleting_dtor_identifier)
6722 pretty_name = concat ("~", pretty_name, NULL);
6723 /* Remember that we need to free the memory allocated. */
6727 else if (IDENTIFIER_TYPENAME_P (name))
6729 pretty_name = concat ("operator ",
6730 type_as_string_translate (TREE_TYPE (name),
6731 TFF_PLAIN_IDENTIFIER),
6733 /* Remember that we need to free the memory allocated. */
6737 pretty_name = CONST_CAST (char *, identifier_to_locale (IDENTIFIER_POINTER (name)));
6742 /* Build a call to "INSTANCE.FN (ARGS)". If FN_P is non-NULL, it will
6743 be set, upon return, to the function called. ARGS may be NULL.
6744 This may change ARGS. */
6747 build_new_method_call (tree instance, tree fns, VEC(tree,gc) **args,
6748 tree conversion_path, int flags,
6749 tree *fn_p, tsubst_flags_t complain)
6751 struct z_candidate *candidates = 0, *cand;
6752 tree explicit_targs = NULL_TREE;
6753 tree basetype = NULL_TREE;
6756 tree first_mem_arg = NULL_TREE;
6759 bool skip_first_for_error;
6760 VEC(tree,gc) *user_args;
6763 int template_only = 0;
6767 VEC(tree,gc) *orig_args = NULL;
6770 gcc_assert (instance != NULL_TREE);
6772 /* We don't know what function we're going to call, yet. */
6776 if (error_operand_p (instance)
6777 || !fns || error_operand_p (fns))
6778 return error_mark_node;
6780 if (!BASELINK_P (fns))
6782 if (complain & tf_error)
6783 error ("call to non-function %qD", fns);
6784 return error_mark_node;
6787 orig_instance = instance;
6790 /* Dismantle the baselink to collect all the information we need. */
6791 if (!conversion_path)
6792 conversion_path = BASELINK_BINFO (fns);
6793 access_binfo = BASELINK_ACCESS_BINFO (fns);
6794 optype = BASELINK_OPTYPE (fns);
6795 fns = BASELINK_FUNCTIONS (fns);
6796 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
6798 explicit_targs = TREE_OPERAND (fns, 1);
6799 fns = TREE_OPERAND (fns, 0);
6802 gcc_assert (TREE_CODE (fns) == FUNCTION_DECL
6803 || TREE_CODE (fns) == TEMPLATE_DECL
6804 || TREE_CODE (fns) == OVERLOAD);
6805 fn = get_first_fn (fns);
6806 name = DECL_NAME (fn);
6808 basetype = TYPE_MAIN_VARIANT (TREE_TYPE (instance));
6809 gcc_assert (CLASS_TYPE_P (basetype));
6811 if (processing_template_decl)
6813 orig_args = args == NULL ? NULL : make_tree_vector_copy (*args);
6814 instance = build_non_dependent_expr (instance);
6816 make_args_non_dependent (*args);
6819 user_args = args == NULL ? NULL : *args;
6820 /* Under DR 147 A::A() is an invalid constructor call,
6821 not a functional cast. */
6822 if (DECL_MAYBE_IN_CHARGE_CONSTRUCTOR_P (fn))
6824 if (! (complain & tf_error))
6825 return error_mark_node;
6827 permerror (input_location,
6828 "cannot call constructor %<%T::%D%> directly",
6830 permerror (input_location, " for a function-style cast, remove the "
6831 "redundant %<::%D%>", name);
6832 call = build_functional_cast (basetype, build_tree_list_vec (user_args),
6837 /* Figure out whether to skip the first argument for the error
6838 message we will display to users if an error occurs. We don't
6839 want to display any compiler-generated arguments. The "this"
6840 pointer hasn't been added yet. However, we must remove the VTT
6841 pointer if this is a call to a base-class constructor or
6843 skip_first_for_error = false;
6844 if (IDENTIFIER_CTOR_OR_DTOR_P (name))
6846 /* Callers should explicitly indicate whether they want to construct
6847 the complete object or just the part without virtual bases. */
6848 gcc_assert (name != ctor_identifier);
6849 /* Similarly for destructors. */
6850 gcc_assert (name != dtor_identifier);
6851 /* Remove the VTT pointer, if present. */
6852 if ((name == base_ctor_identifier || name == base_dtor_identifier)
6853 && CLASSTYPE_VBASECLASSES (basetype))
6854 skip_first_for_error = true;
6857 /* Process the argument list. */
6858 if (args != NULL && *args != NULL)
6860 *args = resolve_args (*args, complain);
6862 return error_mark_node;
6865 instance_ptr = build_this (instance);
6867 /* It's OK to call destructors and constructors on cv-qualified objects.
6868 Therefore, convert the INSTANCE_PTR to the unqualified type, if
6870 if (DECL_DESTRUCTOR_P (fn)
6871 || DECL_CONSTRUCTOR_P (fn))
6873 tree type = build_pointer_type (basetype);
6874 if (!same_type_p (type, TREE_TYPE (instance_ptr)))
6875 instance_ptr = build_nop (type, instance_ptr);
6877 if (DECL_DESTRUCTOR_P (fn))
6878 name = complete_dtor_identifier;
6880 first_mem_arg = instance_ptr;
6882 /* Get the high-water mark for the CONVERSION_OBSTACK. */
6883 p = conversion_obstack_alloc (0);
6885 /* If CONSTRUCTOR_IS_DIRECT_INIT is set, this was a T{ } form
6886 initializer, not T({ }). */
6887 if (DECL_CONSTRUCTOR_P (fn) && args != NULL && !VEC_empty (tree, *args)
6888 && BRACE_ENCLOSED_INITIALIZER_P (VEC_index (tree, *args, 0))
6889 && CONSTRUCTOR_IS_DIRECT_INIT (VEC_index (tree, *args, 0)))
6891 gcc_assert (VEC_length (tree, *args) == 1
6892 && !(flags & LOOKUP_ONLYCONVERTING));
6894 add_list_candidates (fns, first_mem_arg, VEC_index (tree, *args, 0),
6895 basetype, explicit_targs, template_only,
6896 conversion_path, access_binfo, flags, &candidates);
6900 add_candidates (fns, first_mem_arg, user_args, optype,
6901 explicit_targs, template_only, conversion_path,
6902 access_binfo, flags, &candidates);
6904 any_viable_p = false;
6905 candidates = splice_viable (candidates, pedantic, &any_viable_p);
6909 if (complain & tf_error)
6911 if (!COMPLETE_OR_OPEN_TYPE_P (basetype))
6912 cxx_incomplete_type_error (instance_ptr, basetype);
6914 error ("no matching function for call to %<%T::operator %T(%A)%#V%>",
6915 basetype, optype, build_tree_list_vec (user_args),
6916 TREE_TYPE (TREE_TYPE (instance_ptr)));
6923 pretty_name = name_as_c_string (name, basetype, &free_p);
6924 arglist = build_tree_list_vec (user_args);
6925 if (skip_first_for_error)
6926 arglist = TREE_CHAIN (arglist);
6927 error ("no matching function for call to %<%T::%s(%A)%#V%>",
6928 basetype, pretty_name, arglist,
6929 TREE_TYPE (TREE_TYPE (instance_ptr)));
6933 print_z_candidates (location_of (name), candidates);
6935 call = error_mark_node;
6939 cand = tourney (candidates);
6946 if (complain & tf_error)
6948 pretty_name = name_as_c_string (name, basetype, &free_p);
6949 arglist = build_tree_list_vec (user_args);
6950 if (skip_first_for_error)
6951 arglist = TREE_CHAIN (arglist);
6952 error ("call of overloaded %<%s(%A)%> is ambiguous", pretty_name,
6954 print_z_candidates (location_of (name), candidates);
6958 call = error_mark_node;
6964 if (!(flags & LOOKUP_NONVIRTUAL)
6965 && DECL_PURE_VIRTUAL_P (fn)
6966 && instance == current_class_ref
6967 && (DECL_CONSTRUCTOR_P (current_function_decl)
6968 || DECL_DESTRUCTOR_P (current_function_decl))
6969 && (complain & tf_warning))
6970 /* This is not an error, it is runtime undefined
6972 warning (0, (DECL_CONSTRUCTOR_P (current_function_decl) ?
6973 "pure virtual %q#D called from constructor"
6974 : "pure virtual %q#D called from destructor"),
6977 if (TREE_CODE (TREE_TYPE (fn)) == METHOD_TYPE
6978 && is_dummy_object (instance_ptr))
6980 if (complain & tf_error)
6981 error ("cannot call member function %qD without object",
6983 call = error_mark_node;
6987 if (DECL_VINDEX (fn) && ! (flags & LOOKUP_NONVIRTUAL)
6988 && resolves_to_fixed_type_p (instance, 0))
6989 flags |= LOOKUP_NONVIRTUAL;
6990 /* Now we know what function is being called. */
6993 /* Build the actual CALL_EXPR. */
6994 call = build_over_call (cand, flags, complain);
6995 /* In an expression of the form `a->f()' where `f' turns
6996 out to be a static member function, `a' is
6997 none-the-less evaluated. */
6998 if (TREE_CODE (TREE_TYPE (fn)) != METHOD_TYPE
6999 && !is_dummy_object (instance_ptr)
7000 && TREE_SIDE_EFFECTS (instance_ptr))
7001 call = build2 (COMPOUND_EXPR, TREE_TYPE (call),
7002 instance_ptr, call);
7003 else if (call != error_mark_node
7004 && DECL_DESTRUCTOR_P (cand->fn)
7005 && !VOID_TYPE_P (TREE_TYPE (call)))
7006 /* An explicit call of the form "x->~X()" has type
7007 "void". However, on platforms where destructors
7008 return "this" (i.e., those where
7009 targetm.cxx.cdtor_returns_this is true), such calls
7010 will appear to have a return value of pointer type
7011 to the low-level call machinery. We do not want to
7012 change the low-level machinery, since we want to be
7013 able to optimize "delete f()" on such platforms as
7014 "operator delete(~X(f()))" (rather than generating
7015 "t = f(), ~X(t), operator delete (t)"). */
7016 call = build_nop (void_type_node, call);
7021 if (processing_template_decl && call != error_mark_node)
7023 bool cast_to_void = false;
7025 if (TREE_CODE (call) == COMPOUND_EXPR)
7026 call = TREE_OPERAND (call, 1);
7027 else if (TREE_CODE (call) == NOP_EXPR)
7029 cast_to_void = true;
7030 call = TREE_OPERAND (call, 0);
7032 if (TREE_CODE (call) == INDIRECT_REF)
7033 call = TREE_OPERAND (call, 0);
7034 call = (build_min_non_dep_call_vec
7036 build_min (COMPONENT_REF, TREE_TYPE (CALL_EXPR_FN (call)),
7037 orig_instance, orig_fns, NULL_TREE),
7039 call = convert_from_reference (call);
7041 call = build_nop (void_type_node, call);
7044 /* Free all the conversions we allocated. */
7045 obstack_free (&conversion_obstack, p);
7047 if (orig_args != NULL)
7048 release_tree_vector (orig_args);
7053 /* Returns true iff standard conversion sequence ICS1 is a proper
7054 subsequence of ICS2. */
7057 is_subseq (conversion *ics1, conversion *ics2)
7059 /* We can assume that a conversion of the same code
7060 between the same types indicates a subsequence since we only get
7061 here if the types we are converting from are the same. */
7063 while (ics1->kind == ck_rvalue
7064 || ics1->kind == ck_lvalue)
7065 ics1 = ics1->u.next;
7069 while (ics2->kind == ck_rvalue
7070 || ics2->kind == ck_lvalue)
7071 ics2 = ics2->u.next;
7073 if (ics2->kind == ck_user
7074 || ics2->kind == ck_ambig
7075 || ics2->kind == ck_aggr
7076 || ics2->kind == ck_list
7077 || ics2->kind == ck_identity)
7078 /* At this point, ICS1 cannot be a proper subsequence of
7079 ICS2. We can get a USER_CONV when we are comparing the
7080 second standard conversion sequence of two user conversion
7084 ics2 = ics2->u.next;
7086 if (ics2->kind == ics1->kind
7087 && same_type_p (ics2->type, ics1->type)
7088 && same_type_p (ics2->u.next->type,
7089 ics1->u.next->type))
7094 /* Returns nonzero iff DERIVED is derived from BASE. The inputs may
7095 be any _TYPE nodes. */
7098 is_properly_derived_from (tree derived, tree base)
7100 if (!CLASS_TYPE_P (derived) || !CLASS_TYPE_P (base))
7103 /* We only allow proper derivation here. The DERIVED_FROM_P macro
7104 considers every class derived from itself. */
7105 return (!same_type_ignoring_top_level_qualifiers_p (derived, base)
7106 && DERIVED_FROM_P (base, derived));
7109 /* We build the ICS for an implicit object parameter as a pointer
7110 conversion sequence. However, such a sequence should be compared
7111 as if it were a reference conversion sequence. If ICS is the
7112 implicit conversion sequence for an implicit object parameter,
7113 modify it accordingly. */
7116 maybe_handle_implicit_object (conversion **ics)
7120 /* [over.match.funcs]
7122 For non-static member functions, the type of the
7123 implicit object parameter is "reference to cv X"
7124 where X is the class of which the function is a
7125 member and cv is the cv-qualification on the member
7126 function declaration. */
7127 conversion *t = *ics;
7128 tree reference_type;
7130 /* The `this' parameter is a pointer to a class type. Make the
7131 implicit conversion talk about a reference to that same class
7133 reference_type = TREE_TYPE (t->type);
7134 reference_type = build_reference_type (reference_type);
7136 if (t->kind == ck_qual)
7138 if (t->kind == ck_ptr)
7140 t = build_identity_conv (TREE_TYPE (t->type), NULL_TREE);
7141 t = direct_reference_binding (reference_type, t);
7143 t->rvaluedness_matches_p = 0;
7148 /* If *ICS is a REF_BIND set *ICS to the remainder of the conversion,
7149 and return the initial reference binding conversion. Otherwise,
7150 leave *ICS unchanged and return NULL. */
7153 maybe_handle_ref_bind (conversion **ics)
7155 if ((*ics)->kind == ck_ref_bind)
7157 conversion *old_ics = *ics;
7158 *ics = old_ics->u.next;
7159 (*ics)->user_conv_p = old_ics->user_conv_p;
7166 /* Compare two implicit conversion sequences according to the rules set out in
7167 [over.ics.rank]. Return values:
7169 1: ics1 is better than ics2
7170 -1: ics2 is better than ics1
7171 0: ics1 and ics2 are indistinguishable */
7174 compare_ics (conversion *ics1, conversion *ics2)
7180 tree deref_from_type1 = NULL_TREE;
7181 tree deref_from_type2 = NULL_TREE;
7182 tree deref_to_type1 = NULL_TREE;
7183 tree deref_to_type2 = NULL_TREE;
7184 conversion_rank rank1, rank2;
7186 /* REF_BINDING is nonzero if the result of the conversion sequence
7187 is a reference type. In that case REF_CONV is the reference
7188 binding conversion. */
7189 conversion *ref_conv1;
7190 conversion *ref_conv2;
7192 /* Handle implicit object parameters. */
7193 maybe_handle_implicit_object (&ics1);
7194 maybe_handle_implicit_object (&ics2);
7196 /* Handle reference parameters. */
7197 ref_conv1 = maybe_handle_ref_bind (&ics1);
7198 ref_conv2 = maybe_handle_ref_bind (&ics2);
7200 /* List-initialization sequence L1 is a better conversion sequence than
7201 list-initialization sequence L2 if L1 converts to
7202 std::initializer_list<X> for some X and L2 does not. */
7203 if (ics1->kind == ck_list && ics2->kind != ck_list)
7205 if (ics2->kind == ck_list && ics1->kind != ck_list)
7210 When comparing the basic forms of implicit conversion sequences (as
7211 defined in _over.best.ics_)
7213 --a standard conversion sequence (_over.ics.scs_) is a better
7214 conversion sequence than a user-defined conversion sequence
7215 or an ellipsis conversion sequence, and
7217 --a user-defined conversion sequence (_over.ics.user_) is a
7218 better conversion sequence than an ellipsis conversion sequence
7219 (_over.ics.ellipsis_). */
7220 rank1 = CONVERSION_RANK (ics1);
7221 rank2 = CONVERSION_RANK (ics2);
7225 else if (rank1 < rank2)
7228 if (rank1 == cr_bad)
7230 /* Both ICS are bad. We try to make a decision based on what would
7231 have happened if they'd been good. This is not an extension,
7232 we'll still give an error when we build up the call; this just
7233 helps us give a more helpful error message. */
7234 rank1 = BAD_CONVERSION_RANK (ics1);
7235 rank2 = BAD_CONVERSION_RANK (ics2);
7239 else if (rank1 < rank2)
7242 /* We couldn't make up our minds; try to figure it out below. */
7245 if (ics1->ellipsis_p)
7246 /* Both conversions are ellipsis conversions. */
7249 /* User-defined conversion sequence U1 is a better conversion sequence
7250 than another user-defined conversion sequence U2 if they contain the
7251 same user-defined conversion operator or constructor and if the sec-
7252 ond standard conversion sequence of U1 is better than the second
7253 standard conversion sequence of U2. */
7255 /* Handle list-conversion with the same code even though it isn't always
7256 ranked as a user-defined conversion and it doesn't have a second
7257 standard conversion sequence; it will still have the desired effect.
7258 Specifically, we need to do the reference binding comparison at the
7259 end of this function. */
7261 if (ics1->user_conv_p || ics1->kind == ck_list)
7266 for (t1 = ics1; t1->kind != ck_user; t1 = t1->u.next)
7267 if (t1->kind == ck_ambig || t1->kind == ck_aggr
7268 || t1->kind == ck_list)
7270 for (t2 = ics2; t2->kind != ck_user; t2 = t2->u.next)
7271 if (t2->kind == ck_ambig || t2->kind == ck_aggr
7272 || t2->kind == ck_list)
7275 if (t1->kind != t2->kind)
7277 else if (t1->kind == ck_user)
7279 if (t1->cand->fn != t2->cand->fn)
7284 /* For ambiguous or aggregate conversions, use the target type as
7285 a proxy for the conversion function. */
7286 if (!same_type_ignoring_top_level_qualifiers_p (t1->type, t2->type))
7290 /* We can just fall through here, after setting up
7291 FROM_TYPE1 and FROM_TYPE2. */
7292 from_type1 = t1->type;
7293 from_type2 = t2->type;
7300 /* We're dealing with two standard conversion sequences.
7304 Standard conversion sequence S1 is a better conversion
7305 sequence than standard conversion sequence S2 if
7307 --S1 is a proper subsequence of S2 (comparing the conversion
7308 sequences in the canonical form defined by _over.ics.scs_,
7309 excluding any Lvalue Transformation; the identity
7310 conversion sequence is considered to be a subsequence of
7311 any non-identity conversion sequence */
7314 while (t1->kind != ck_identity)
7316 from_type1 = t1->type;
7319 while (t2->kind != ck_identity)
7321 from_type2 = t2->type;
7324 /* One sequence can only be a subsequence of the other if they start with
7325 the same type. They can start with different types when comparing the
7326 second standard conversion sequence in two user-defined conversion
7328 if (same_type_p (from_type1, from_type2))
7330 if (is_subseq (ics1, ics2))
7332 if (is_subseq (ics2, ics1))
7340 --the rank of S1 is better than the rank of S2 (by the rules
7343 Standard conversion sequences are ordered by their ranks: an Exact
7344 Match is a better conversion than a Promotion, which is a better
7345 conversion than a Conversion.
7347 Two conversion sequences with the same rank are indistinguishable
7348 unless one of the following rules applies:
7350 --A conversion that does not a convert a pointer, pointer to member,
7351 or std::nullptr_t to bool is better than one that does.
7353 The ICS_STD_RANK automatically handles the pointer-to-bool rule,
7354 so that we do not have to check it explicitly. */
7355 if (ics1->rank < ics2->rank)
7357 else if (ics2->rank < ics1->rank)
7360 to_type1 = ics1->type;
7361 to_type2 = ics2->type;
7363 /* A conversion from scalar arithmetic type to complex is worse than a
7364 conversion between scalar arithmetic types. */
7365 if (same_type_p (from_type1, from_type2)
7366 && ARITHMETIC_TYPE_P (from_type1)
7367 && ARITHMETIC_TYPE_P (to_type1)
7368 && ARITHMETIC_TYPE_P (to_type2)
7369 && ((TREE_CODE (to_type1) == COMPLEX_TYPE)
7370 != (TREE_CODE (to_type2) == COMPLEX_TYPE)))
7372 if (TREE_CODE (to_type1) == COMPLEX_TYPE)
7378 if (TYPE_PTR_P (from_type1)
7379 && TYPE_PTR_P (from_type2)
7380 && TYPE_PTR_P (to_type1)
7381 && TYPE_PTR_P (to_type2))
7383 deref_from_type1 = TREE_TYPE (from_type1);
7384 deref_from_type2 = TREE_TYPE (from_type2);
7385 deref_to_type1 = TREE_TYPE (to_type1);
7386 deref_to_type2 = TREE_TYPE (to_type2);
7388 /* The rules for pointers to members A::* are just like the rules
7389 for pointers A*, except opposite: if B is derived from A then
7390 A::* converts to B::*, not vice versa. For that reason, we
7391 switch the from_ and to_ variables here. */
7392 else if ((TYPE_PTRMEM_P (from_type1) && TYPE_PTRMEM_P (from_type2)
7393 && TYPE_PTRMEM_P (to_type1) && TYPE_PTRMEM_P (to_type2))
7394 || (TYPE_PTRMEMFUNC_P (from_type1)
7395 && TYPE_PTRMEMFUNC_P (from_type2)
7396 && TYPE_PTRMEMFUNC_P (to_type1)
7397 && TYPE_PTRMEMFUNC_P (to_type2)))
7399 deref_to_type1 = TYPE_PTRMEM_CLASS_TYPE (from_type1);
7400 deref_to_type2 = TYPE_PTRMEM_CLASS_TYPE (from_type2);
7401 deref_from_type1 = TYPE_PTRMEM_CLASS_TYPE (to_type1);
7402 deref_from_type2 = TYPE_PTRMEM_CLASS_TYPE (to_type2);
7405 if (deref_from_type1 != NULL_TREE
7406 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type1))
7407 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_from_type2)))
7409 /* This was one of the pointer or pointer-like conversions.
7413 --If class B is derived directly or indirectly from class A,
7414 conversion of B* to A* is better than conversion of B* to
7415 void*, and conversion of A* to void* is better than
7416 conversion of B* to void*. */
7417 if (TREE_CODE (deref_to_type1) == VOID_TYPE
7418 && TREE_CODE (deref_to_type2) == VOID_TYPE)
7420 if (is_properly_derived_from (deref_from_type1,
7423 else if (is_properly_derived_from (deref_from_type2,
7427 else if (TREE_CODE (deref_to_type1) == VOID_TYPE
7428 || TREE_CODE (deref_to_type2) == VOID_TYPE)
7430 if (same_type_p (deref_from_type1, deref_from_type2))
7432 if (TREE_CODE (deref_to_type2) == VOID_TYPE)
7434 if (is_properly_derived_from (deref_from_type1,
7438 /* We know that DEREF_TO_TYPE1 is `void' here. */
7439 else if (is_properly_derived_from (deref_from_type1,
7444 else if (RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type1))
7445 && RECORD_OR_UNION_CODE_P (TREE_CODE (deref_to_type2)))
7449 --If class B is derived directly or indirectly from class A
7450 and class C is derived directly or indirectly from B,
7452 --conversion of C* to B* is better than conversion of C* to
7455 --conversion of B* to A* is better than conversion of C* to
7457 if (same_type_p (deref_from_type1, deref_from_type2))
7459 if (is_properly_derived_from (deref_to_type1,
7462 else if (is_properly_derived_from (deref_to_type2,
7466 else if (same_type_p (deref_to_type1, deref_to_type2))
7468 if (is_properly_derived_from (deref_from_type2,
7471 else if (is_properly_derived_from (deref_from_type1,
7477 else if (CLASS_TYPE_P (non_reference (from_type1))
7478 && same_type_p (from_type1, from_type2))
7480 tree from = non_reference (from_type1);
7484 --binding of an expression of type C to a reference of type
7485 B& is better than binding an expression of type C to a
7486 reference of type A&
7488 --conversion of C to B is better than conversion of C to A, */
7489 if (is_properly_derived_from (from, to_type1)
7490 && is_properly_derived_from (from, to_type2))
7492 if (is_properly_derived_from (to_type1, to_type2))
7494 else if (is_properly_derived_from (to_type2, to_type1))
7498 else if (CLASS_TYPE_P (non_reference (to_type1))
7499 && same_type_p (to_type1, to_type2))
7501 tree to = non_reference (to_type1);
7505 --binding of an expression of type B to a reference of type
7506 A& is better than binding an expression of type C to a
7507 reference of type A&,
7509 --conversion of B to A is better than conversion of C to A */
7510 if (is_properly_derived_from (from_type1, to)
7511 && is_properly_derived_from (from_type2, to))
7513 if (is_properly_derived_from (from_type2, from_type1))
7515 else if (is_properly_derived_from (from_type1, from_type2))
7522 --S1 and S2 differ only in their qualification conversion and yield
7523 similar types T1 and T2 (_conv.qual_), respectively, and the cv-
7524 qualification signature of type T1 is a proper subset of the cv-
7525 qualification signature of type T2 */
7526 if (ics1->kind == ck_qual
7527 && ics2->kind == ck_qual
7528 && same_type_p (from_type1, from_type2))
7530 int result = comp_cv_qual_signature (to_type1, to_type2);
7537 --S1 and S2 are reference bindings (_dcl.init.ref_) and neither refers
7538 to an implicit object parameter, and either S1 binds an lvalue reference
7539 to an lvalue and S2 binds an rvalue reference or S1 binds an rvalue
7540 reference to an rvalue and S2 binds an lvalue reference
7541 (C++0x draft standard, 13.3.3.2)
7543 --S1 and S2 are reference bindings (_dcl.init.ref_), and the
7544 types to which the references refer are the same type except for
7545 top-level cv-qualifiers, and the type to which the reference
7546 initialized by S2 refers is more cv-qualified than the type to
7547 which the reference initialized by S1 refers */
7549 if (ref_conv1 && ref_conv2)
7551 if (!ref_conv1->this_p && !ref_conv2->this_p
7552 && (TYPE_REF_IS_RVALUE (ref_conv1->type)
7553 != TYPE_REF_IS_RVALUE (ref_conv2->type)))
7555 if (ref_conv1->rvaluedness_matches_p)
7557 if (ref_conv2->rvaluedness_matches_p)
7561 if (same_type_ignoring_top_level_qualifiers_p (to_type1, to_type2))
7562 return comp_cv_qualification (TREE_TYPE (ref_conv2->type),
7563 TREE_TYPE (ref_conv1->type));
7566 /* Neither conversion sequence is better than the other. */
7570 /* The source type for this standard conversion sequence. */
7573 source_type (conversion *t)
7575 for (;; t = t->u.next)
7577 if (t->kind == ck_user
7578 || t->kind == ck_ambig
7579 || t->kind == ck_identity)
7585 /* Note a warning about preferring WINNER to LOSER. We do this by storing
7586 a pointer to LOSER and re-running joust to produce the warning if WINNER
7587 is actually used. */
7590 add_warning (struct z_candidate *winner, struct z_candidate *loser)
7592 candidate_warning *cw = (candidate_warning *)
7593 conversion_obstack_alloc (sizeof (candidate_warning));
7595 cw->next = winner->warnings;
7596 winner->warnings = cw;
7599 /* Compare two candidates for overloading as described in
7600 [over.match.best]. Return values:
7602 1: cand1 is better than cand2
7603 -1: cand2 is better than cand1
7604 0: cand1 and cand2 are indistinguishable */
7607 joust (struct z_candidate *cand1, struct z_candidate *cand2, bool warn)
7610 int off1 = 0, off2 = 0;
7614 /* Candidates that involve bad conversions are always worse than those
7616 if (cand1->viable > cand2->viable)
7618 if (cand1->viable < cand2->viable)
7621 /* If we have two pseudo-candidates for conversions to the same type,
7622 or two candidates for the same function, arbitrarily pick one. */
7623 if (cand1->fn == cand2->fn
7624 && (IS_TYPE_OR_DECL_P (cand1->fn)))
7627 /* a viable function F1
7628 is defined to be a better function than another viable function F2 if
7629 for all arguments i, ICSi(F1) is not a worse conversion sequence than
7630 ICSi(F2), and then */
7632 /* for some argument j, ICSj(F1) is a better conversion sequence than
7635 /* For comparing static and non-static member functions, we ignore
7636 the implicit object parameter of the non-static function. The
7637 standard says to pretend that the static function has an object
7638 parm, but that won't work with operator overloading. */
7639 len = cand1->num_convs;
7640 if (len != cand2->num_convs)
7642 int static_1 = DECL_STATIC_FUNCTION_P (cand1->fn);
7643 int static_2 = DECL_STATIC_FUNCTION_P (cand2->fn);
7645 gcc_assert (static_1 != static_2);
7656 for (i = 0; i < len; ++i)
7658 conversion *t1 = cand1->convs[i + off1];
7659 conversion *t2 = cand2->convs[i + off2];
7660 int comp = compare_ics (t1, t2);
7665 && (CONVERSION_RANK (t1) + CONVERSION_RANK (t2)
7666 == cr_std + cr_promotion)
7667 && t1->kind == ck_std
7668 && t2->kind == ck_std
7669 && TREE_CODE (t1->type) == INTEGER_TYPE
7670 && TREE_CODE (t2->type) == INTEGER_TYPE
7671 && (TYPE_PRECISION (t1->type)
7672 == TYPE_PRECISION (t2->type))
7673 && (TYPE_UNSIGNED (t1->u.next->type)
7674 || (TREE_CODE (t1->u.next->type)
7677 tree type = t1->u.next->type;
7679 struct z_candidate *w, *l;
7681 type1 = t1->type, type2 = t2->type,
7682 w = cand1, l = cand2;
7684 type1 = t2->type, type2 = t1->type,
7685 w = cand2, l = cand1;
7689 warning (OPT_Wsign_promo, "passing %qT chooses %qT over %qT",
7690 type, type1, type2);
7691 warning (OPT_Wsign_promo, " in call to %qD", w->fn);
7697 if (winner && comp != winner)
7706 /* warn about confusing overload resolution for user-defined conversions,
7707 either between a constructor and a conversion op, or between two
7709 if (winner && warn_conversion && cand1->second_conv
7710 && (!DECL_CONSTRUCTOR_P (cand1->fn) || !DECL_CONSTRUCTOR_P (cand2->fn))
7711 && winner != compare_ics (cand1->second_conv, cand2->second_conv))
7713 struct z_candidate *w, *l;
7714 bool give_warning = false;
7717 w = cand1, l = cand2;
7719 w = cand2, l = cand1;
7721 /* We don't want to complain about `X::operator T1 ()'
7722 beating `X::operator T2 () const', when T2 is a no less
7723 cv-qualified version of T1. */
7724 if (DECL_CONTEXT (w->fn) == DECL_CONTEXT (l->fn)
7725 && !DECL_CONSTRUCTOR_P (w->fn) && !DECL_CONSTRUCTOR_P (l->fn))
7727 tree t = TREE_TYPE (TREE_TYPE (l->fn));
7728 tree f = TREE_TYPE (TREE_TYPE (w->fn));
7730 if (TREE_CODE (t) == TREE_CODE (f) && POINTER_TYPE_P (t))
7735 if (!comp_ptr_ttypes (t, f))
7736 give_warning = true;
7739 give_warning = true;
7745 tree source = source_type (w->convs[0]);
7746 if (! DECL_CONSTRUCTOR_P (w->fn))
7747 source = TREE_TYPE (source);
7748 if (warning (OPT_Wconversion, "choosing %qD over %qD", w->fn, l->fn)
7749 && warning (OPT_Wconversion, " for conversion from %qT to %qT",
7750 source, w->second_conv->type))
7752 inform (input_location, " because conversion sequence for the argument is better");
7763 F1 is a non-template function and F2 is a template function
7766 if (!cand1->template_decl && cand2->template_decl)
7768 else if (cand1->template_decl && !cand2->template_decl)
7772 F1 and F2 are template functions and the function template for F1 is
7773 more specialized than the template for F2 according to the partial
7776 if (cand1->template_decl && cand2->template_decl)
7778 winner = more_specialized_fn
7779 (TI_TEMPLATE (cand1->template_decl),
7780 TI_TEMPLATE (cand2->template_decl),
7781 /* [temp.func.order]: The presence of unused ellipsis and default
7782 arguments has no effect on the partial ordering of function
7783 templates. add_function_candidate() will not have
7784 counted the "this" argument for constructors. */
7785 cand1->num_convs + DECL_CONSTRUCTOR_P (cand1->fn));
7791 the context is an initialization by user-defined conversion (see
7792 _dcl.init_ and _over.match.user_) and the standard conversion
7793 sequence from the return type of F1 to the destination type (i.e.,
7794 the type of the entity being initialized) is a better conversion
7795 sequence than the standard conversion sequence from the return type
7796 of F2 to the destination type. */
7798 if (cand1->second_conv)
7800 winner = compare_ics (cand1->second_conv, cand2->second_conv);
7805 /* Check whether we can discard a builtin candidate, either because we
7806 have two identical ones or matching builtin and non-builtin candidates.
7808 (Pedantically in the latter case the builtin which matched the user
7809 function should not be added to the overload set, but we spot it here.
7812 ... the builtin candidates include ...
7813 - do not have the same parameter type list as any non-template
7814 non-member candidate. */
7816 if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE
7817 || TREE_CODE (cand2->fn) == IDENTIFIER_NODE)
7819 for (i = 0; i < len; ++i)
7820 if (!same_type_p (cand1->convs[i]->type,
7821 cand2->convs[i]->type))
7823 if (i == cand1->num_convs)
7825 if (cand1->fn == cand2->fn)
7826 /* Two built-in candidates; arbitrarily pick one. */
7828 else if (TREE_CODE (cand1->fn) == IDENTIFIER_NODE)
7829 /* cand1 is built-in; prefer cand2. */
7832 /* cand2 is built-in; prefer cand1. */
7837 /* If the two function declarations represent the same function (this can
7838 happen with declarations in multiple scopes and arg-dependent lookup),
7839 arbitrarily choose one. But first make sure the default args we're
7841 if (DECL_P (cand1->fn) && DECL_P (cand2->fn)
7842 && equal_functions (cand1->fn, cand2->fn))
7844 tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (cand1->fn));
7845 tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (cand2->fn));
7847 gcc_assert (!DECL_CONSTRUCTOR_P (cand1->fn));
7849 for (i = 0; i < len; ++i)
7851 /* Don't crash if the fn is variadic. */
7854 parms1 = TREE_CHAIN (parms1);
7855 parms2 = TREE_CHAIN (parms2);
7859 parms1 = TREE_CHAIN (parms1);
7861 parms2 = TREE_CHAIN (parms2);
7865 if (!cp_tree_equal (TREE_PURPOSE (parms1),
7866 TREE_PURPOSE (parms2)))
7870 permerror (input_location, "default argument mismatch in "
7871 "overload resolution");
7872 inform (input_location,
7873 " candidate 1: %q+#F", cand1->fn);
7874 inform (input_location,
7875 " candidate 2: %q+#F", cand2->fn);
7878 add_warning (cand1, cand2);
7881 parms1 = TREE_CHAIN (parms1);
7882 parms2 = TREE_CHAIN (parms2);
7890 /* Extension: If the worst conversion for one candidate is worse than the
7891 worst conversion for the other, take the first. */
7894 conversion_rank rank1 = cr_identity, rank2 = cr_identity;
7895 struct z_candidate *w = 0, *l = 0;
7897 for (i = 0; i < len; ++i)
7899 if (CONVERSION_RANK (cand1->convs[i+off1]) > rank1)
7900 rank1 = CONVERSION_RANK (cand1->convs[i+off1]);
7901 if (CONVERSION_RANK (cand2->convs[i + off2]) > rank2)
7902 rank2 = CONVERSION_RANK (cand2->convs[i + off2]);
7905 winner = 1, w = cand1, l = cand2;
7907 winner = -1, w = cand2, l = cand1;
7910 /* Don't choose a deleted function over ambiguity. */
7911 if (DECL_P (w->fn) && DECL_DELETED_FN (w->fn))
7915 pedwarn (input_location, 0,
7916 "ISO C++ says that these are ambiguous, even "
7917 "though the worst conversion for the first is better than "
7918 "the worst conversion for the second:");
7919 print_z_candidate (_("candidate 1:"), w);
7920 print_z_candidate (_("candidate 2:"), l);
7928 gcc_assert (!winner);
7932 /* Given a list of candidates for overloading, find the best one, if any.
7933 This algorithm has a worst case of O(2n) (winner is last), and a best
7934 case of O(n/2) (totally ambiguous); much better than a sorting
7937 static struct z_candidate *
7938 tourney (struct z_candidate *candidates)
7940 struct z_candidate *champ = candidates, *challenger;
7942 int champ_compared_to_predecessor = 0;
7944 /* Walk through the list once, comparing each current champ to the next
7945 candidate, knocking out a candidate or two with each comparison. */
7947 for (challenger = champ->next; challenger; )
7949 fate = joust (champ, challenger, 0);
7951 challenger = challenger->next;
7956 champ = challenger->next;
7959 champ_compared_to_predecessor = 0;
7964 champ_compared_to_predecessor = 1;
7967 challenger = champ->next;
7971 /* Make sure the champ is better than all the candidates it hasn't yet
7972 been compared to. */
7974 for (challenger = candidates;
7976 && !(champ_compared_to_predecessor && challenger->next == champ);
7977 challenger = challenger->next)
7979 fate = joust (champ, challenger, 0);
7987 /* Returns nonzero if things of type FROM can be converted to TO. */
7990 can_convert (tree to, tree from)
7992 return can_convert_arg (to, from, NULL_TREE, LOOKUP_IMPLICIT);
7995 /* Returns nonzero if ARG (of type FROM) can be converted to TO. */
7998 can_convert_arg (tree to, tree from, tree arg, int flags)
8004 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8005 p = conversion_obstack_alloc (0);
8007 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8009 ok_p = (t && !t->bad_p);
8011 /* Free all the conversions we allocated. */
8012 obstack_free (&conversion_obstack, p);
8017 /* Like can_convert_arg, but allows dubious conversions as well. */
8020 can_convert_arg_bad (tree to, tree from, tree arg, int flags)
8025 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8026 p = conversion_obstack_alloc (0);
8027 /* Try to perform the conversion. */
8028 t = implicit_conversion (to, from, arg, /*c_cast_p=*/false,
8030 /* Free all the conversions we allocated. */
8031 obstack_free (&conversion_obstack, p);
8036 /* Convert EXPR to TYPE. Return the converted expression.
8038 Note that we allow bad conversions here because by the time we get to
8039 this point we are committed to doing the conversion. If we end up
8040 doing a bad conversion, convert_like will complain. */
8043 perform_implicit_conversion_flags (tree type, tree expr, tsubst_flags_t complain, int flags)
8048 if (error_operand_p (expr))
8049 return error_mark_node;
8051 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8052 p = conversion_obstack_alloc (0);
8054 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8060 if (complain & tf_error)
8062 /* If expr has unknown type, then it is an overloaded function.
8063 Call instantiate_type to get good error messages. */
8064 if (TREE_TYPE (expr) == unknown_type_node)
8065 instantiate_type (type, expr, complain);
8066 else if (invalid_nonstatic_memfn_p (expr, complain))
8067 /* We gave an error. */;
8069 error ("could not convert %qE to %qT", expr, type);
8071 expr = error_mark_node;
8073 else if (processing_template_decl)
8075 /* In a template, we are only concerned about determining the
8076 type of non-dependent expressions, so we do not have to
8077 perform the actual conversion. */
8078 if (TREE_TYPE (expr) != type)
8079 expr = build_nop (type, expr);
8082 expr = convert_like (conv, expr, complain);
8084 /* Free all the conversions we allocated. */
8085 obstack_free (&conversion_obstack, p);
8091 perform_implicit_conversion (tree type, tree expr, tsubst_flags_t complain)
8093 return perform_implicit_conversion_flags (type, expr, complain, LOOKUP_IMPLICIT);
8096 /* Convert EXPR to TYPE (as a direct-initialization) if that is
8097 permitted. If the conversion is valid, the converted expression is
8098 returned. Otherwise, NULL_TREE is returned, except in the case
8099 that TYPE is a class type; in that case, an error is issued. If
8100 C_CAST_P is true, then this direction initialization is taking
8101 place as part of a static_cast being attempted as part of a C-style
8105 perform_direct_initialization_if_possible (tree type,
8108 tsubst_flags_t complain)
8113 if (type == error_mark_node || error_operand_p (expr))
8114 return error_mark_node;
8117 If the destination type is a (possibly cv-qualified) class type:
8119 -- If the initialization is direct-initialization ...,
8120 constructors are considered. ... If no constructor applies, or
8121 the overload resolution is ambiguous, the initialization is
8123 if (CLASS_TYPE_P (type))
8125 VEC(tree,gc) *args = make_tree_vector_single (expr);
8126 expr = build_special_member_call (NULL_TREE, complete_ctor_identifier,
8127 &args, type, LOOKUP_NORMAL, complain);
8128 release_tree_vector (args);
8129 return build_cplus_new (type, expr, complain);
8132 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8133 p = conversion_obstack_alloc (0);
8135 conv = implicit_conversion (type, TREE_TYPE (expr), expr,
8138 if (!conv || conv->bad_p)
8141 expr = convert_like_real (conv, expr, NULL_TREE, 0, 0,
8142 /*issue_conversion_warnings=*/false,
8146 /* Free all the conversions we allocated. */
8147 obstack_free (&conversion_obstack, p);
8152 /* DECL is a VAR_DECL whose type is a REFERENCE_TYPE. The reference
8153 is being bound to a temporary. Create and return a new VAR_DECL
8154 with the indicated TYPE; this variable will store the value to
8155 which the reference is bound. */
8158 make_temporary_var_for_ref_to_temp (tree decl, tree type)
8162 /* Create the variable. */
8163 var = create_temporary_var (type);
8165 /* Register the variable. */
8166 if (TREE_STATIC (decl))
8168 /* Namespace-scope or local static; give it a mangled name. */
8171 TREE_STATIC (var) = 1;
8172 name = mangle_ref_init_variable (decl);
8173 DECL_NAME (var) = name;
8174 SET_DECL_ASSEMBLER_NAME (var, name);
8175 var = pushdecl_top_level (var);
8178 /* Create a new cleanup level if necessary. */
8179 maybe_push_cleanup_level (type);
8184 /* EXPR is the initializer for a variable DECL of reference or
8185 std::initializer_list type. Create, push and return a new VAR_DECL
8186 for the initializer so that it will live as long as DECL. Any
8187 cleanup for the new variable is returned through CLEANUP, and the
8188 code to initialize the new variable is returned through INITP. */
8191 set_up_extended_ref_temp (tree decl, tree expr, tree *cleanup, tree *initp)
8197 /* Create the temporary variable. */
8198 type = TREE_TYPE (expr);
8199 var = make_temporary_var_for_ref_to_temp (decl, type);
8200 layout_decl (var, 0);
8201 /* If the rvalue is the result of a function call it will be
8202 a TARGET_EXPR. If it is some other construct (such as a
8203 member access expression where the underlying object is
8204 itself the result of a function call), turn it into a
8205 TARGET_EXPR here. It is important that EXPR be a
8206 TARGET_EXPR below since otherwise the INIT_EXPR will
8207 attempt to make a bitwise copy of EXPR to initialize
8209 if (TREE_CODE (expr) != TARGET_EXPR)
8210 expr = get_target_expr (expr);
8212 /* If the initializer is constant, put it in DECL_INITIAL so we get
8213 static initialization and use in constant expressions. */
8214 init = maybe_constant_init (expr);
8215 if (TREE_CONSTANT (init))
8217 if (literal_type_p (type) && CP_TYPE_CONST_NON_VOLATILE_P (type))
8219 /* 5.19 says that a constant expression can include an
8220 lvalue-rvalue conversion applied to "a glvalue of literal type
8221 that refers to a non-volatile temporary object initialized
8222 with a constant expression". Rather than try to communicate
8223 that this VAR_DECL is a temporary, just mark it constexpr.
8225 Currently this is only useful for initializer_list temporaries,
8226 since reference vars can't appear in constant expressions. */
8227 DECL_DECLARED_CONSTEXPR_P (var) = true;
8228 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (var) = true;
8229 TREE_CONSTANT (var) = true;
8231 DECL_INITIAL (var) = init;
8235 /* Create the INIT_EXPR that will initialize the temporary
8237 init = build2 (INIT_EXPR, type, var, expr);
8238 if (at_function_scope_p ())
8240 add_decl_expr (var);
8242 if (TREE_STATIC (var))
8243 init = add_stmt_to_compound (init, register_dtor_fn (var));
8245 *cleanup = cxx_maybe_build_cleanup (var);
8247 /* We must be careful to destroy the temporary only
8248 after its initialization has taken place. If the
8249 initialization throws an exception, then the
8250 destructor should not be run. We cannot simply
8251 transform INIT into something like:
8253 (INIT, ({ CLEANUP_STMT; }))
8255 because emit_local_var always treats the
8256 initializer as a full-expression. Thus, the
8257 destructor would run too early; it would run at the
8258 end of initializing the reference variable, rather
8259 than at the end of the block enclosing the
8262 The solution is to pass back a cleanup expression
8263 which the caller is responsible for attaching to
8264 the statement tree. */
8268 rest_of_decl_compilation (var, /*toplev=*/1, at_eof);
8269 if (TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
8270 static_aggregates = tree_cons (NULL_TREE, var,
8278 /* Convert EXPR to the indicated reference TYPE, in a way suitable for
8279 initializing a variable of that TYPE. If DECL is non-NULL, it is
8280 the VAR_DECL being initialized with the EXPR. (In that case, the
8281 type of DECL will be TYPE.) If DECL is non-NULL, then CLEANUP must
8282 also be non-NULL, and with *CLEANUP initialized to NULL. Upon
8283 return, if *CLEANUP is no longer NULL, it will be an expression
8284 that should be pushed as a cleanup after the returned expression
8285 is used to initialize DECL.
8287 Return the converted expression. */
8290 initialize_reference (tree type, tree expr, tree decl, tree *cleanup,
8291 tsubst_flags_t complain)
8296 if (type == error_mark_node || error_operand_p (expr))
8297 return error_mark_node;
8299 /* Get the high-water mark for the CONVERSION_OBSTACK. */
8300 p = conversion_obstack_alloc (0);
8302 conv = reference_binding (type, TREE_TYPE (expr), expr, /*c_cast_p=*/false,
8304 if (!conv || conv->bad_p)
8306 if (complain & tf_error)
8308 if (!CP_TYPE_CONST_P (TREE_TYPE (type))
8309 && !TYPE_REF_IS_RVALUE (type)
8310 && !real_lvalue_p (expr))
8311 error ("invalid initialization of non-const reference of "
8312 "type %qT from an rvalue of type %qT",
8313 type, TREE_TYPE (expr));
8315 error ("invalid initialization of reference of type "
8316 "%qT from expression of type %qT", type,
8319 return error_mark_node;
8322 /* If DECL is non-NULL, then this special rule applies:
8326 The temporary to which the reference is bound or the temporary
8327 that is the complete object to which the reference is bound
8328 persists for the lifetime of the reference.
8330 The temporaries created during the evaluation of the expression
8331 initializing the reference, except the temporary to which the
8332 reference is bound, are destroyed at the end of the
8333 full-expression in which they are created.
8335 In that case, we store the converted expression into a new
8336 VAR_DECL in a new scope.
8338 However, we want to be careful not to create temporaries when
8339 they are not required. For example, given:
8342 struct D : public B {};
8346 there is no need to copy the return value from "f"; we can just
8347 extend its lifetime. Similarly, given:
8350 struct T { operator S(); };
8354 we can extend the lifetime of the return value of the conversion
8356 gcc_assert (conv->kind == ck_ref_bind);
8360 tree base_conv_type;
8362 /* Skip over the REF_BIND. */
8363 conv = conv->u.next;
8364 /* If the next conversion is a BASE_CONV, skip that too -- but
8365 remember that the conversion was required. */
8366 if (conv->kind == ck_base)
8368 base_conv_type = conv->type;
8369 conv = conv->u.next;
8372 base_conv_type = NULL_TREE;
8373 /* Perform the remainder of the conversion. */
8374 expr = convert_like_real (conv, expr,
8375 /*fn=*/NULL_TREE, /*argnum=*/0,
8377 /*issue_conversion_warnings=*/true,
8379 tf_warning_or_error);
8380 if (error_operand_p (expr))
8381 expr = error_mark_node;
8384 if (!lvalue_or_rvalue_with_address_p (expr))
8387 var = set_up_extended_ref_temp (decl, expr, cleanup, &init);
8388 /* Use its address to initialize the reference variable. */
8389 expr = build_address (var);
8391 expr = convert_to_base (expr,
8392 build_pointer_type (base_conv_type),
8393 /*check_access=*/true,
8394 /*nonnull=*/true, complain);
8396 expr = build2 (COMPOUND_EXPR, TREE_TYPE (expr), init, expr);
8399 /* Take the address of EXPR. */
8400 expr = cp_build_addr_expr (expr, tf_warning_or_error);
8401 /* If a BASE_CONV was required, perform it now. */
8403 expr = (perform_implicit_conversion
8404 (build_pointer_type (base_conv_type), expr,
8405 tf_warning_or_error));
8406 expr = build_nop (type, expr);
8410 /* Perform the conversion. */
8411 expr = convert_like (conv, expr, tf_warning_or_error);
8413 /* Free all the conversions we allocated. */
8414 obstack_free (&conversion_obstack, p);
8419 /* Returns true iff TYPE is some variant of std::initializer_list. */
8422 is_std_init_list (tree type)
8424 /* Look through typedefs. */
8427 type = TYPE_MAIN_VARIANT (type);
8428 return (CLASS_TYPE_P (type)
8429 && CP_TYPE_CONTEXT (type) == std_node
8430 && strcmp (TYPE_NAME_STRING (type), "initializer_list") == 0);
8433 /* Returns true iff DECL is a list constructor: i.e. a constructor which
8434 will accept an argument list of a single std::initializer_list<T>. */
8437 is_list_ctor (tree decl)
8439 tree args = FUNCTION_FIRST_USER_PARMTYPE (decl);
8442 if (!args || args == void_list_node)
8445 arg = non_reference (TREE_VALUE (args));
8446 if (!is_std_init_list (arg))
8449 args = TREE_CHAIN (args);
8451 if (args && args != void_list_node && !TREE_PURPOSE (args))
8452 /* There are more non-defaulted parms. */
8458 #include "gt-cp-call.h"