1 /* Report error messages, build initializers, and perform
2 some front-end optimizations for C++ compiler.
3 Copyright (C) 1987-2015 Free Software Foundation, Inc.
4 Hacked by Michael Tiemann (tiemann@cygnus.com)
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
23 /* This file is part of the C++ front end.
24 It contains routines to build C++ expressions given their operands,
25 including computing the types of the result, C and C++ specific error
26 checks, and some optimization. */
30 #include "coretypes.h"
35 #include "double-int.h"
42 #include "stor-layout.h"
47 #include "diagnostic-core.h"
51 process_init_constructor (tree type, tree init, tsubst_flags_t complain);
54 /* Print an error message stemming from an attempt to use
55 BASETYPE as a base class for TYPE. */
58 error_not_base_type (tree basetype, tree type)
60 if (TREE_CODE (basetype) == FUNCTION_DECL)
61 basetype = DECL_CONTEXT (basetype);
62 error ("type %qT is not a base type for type %qT", basetype, type);
63 return error_mark_node;
67 binfo_or_else (tree base, tree type)
69 tree binfo = lookup_base (type, base, ba_unique,
70 NULL, tf_warning_or_error);
72 if (binfo == error_mark_node)
75 error_not_base_type (base, type);
79 /* According to ARM $7.1.6, "A `const' object may be initialized, but its
80 value may not be changed thereafter. */
83 cxx_readonly_error (tree arg, enum lvalue_use errstring)
86 /* This macro is used to emit diagnostics to ensure that all format
87 strings are complete sentences, visible to gettext and checked at
90 #define ERROR_FOR_ASSIGNMENT(AS, ASM, IN, DE, ARG) \
107 gcc_unreachable (); \
111 /* Handle C++-specific things first. */
114 && DECL_LANG_SPECIFIC (arg)
115 && DECL_IN_AGGR_P (arg)
116 && !TREE_STATIC (arg))
117 ERROR_FOR_ASSIGNMENT (G_("assignment of "
118 "constant field %qD"),
119 G_("constant field %qD "
120 "used as %<asm%> output"),
122 "constant field %qD"),
124 "constant field %qD"),
126 else if (INDIRECT_REF_P (arg)
127 && TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))) == REFERENCE_TYPE
128 && (VAR_P (TREE_OPERAND (arg, 0))
129 || TREE_CODE (TREE_OPERAND (arg, 0)) == PARM_DECL))
130 ERROR_FOR_ASSIGNMENT (G_("assignment of "
131 "read-only reference %qD"),
132 G_("read-only reference %qD "
133 "used as %<asm%> output"),
135 "read-only reference %qD"),
137 "read-only reference %qD"),
138 TREE_OPERAND (arg, 0));
140 readonly_error (input_location, arg, errstring);
144 /* Structure that holds information about declarations whose type was
145 incomplete and we could not check whether it was abstract or not. */
147 struct GTY((chain_next ("%h.next"), for_user)) pending_abstract_type {
148 /* Declaration which we are checking for abstractness. It is either
149 a DECL node, or an IDENTIFIER_NODE if we do not have a full
150 declaration available. */
153 /* Type which will be checked for abstractness. */
156 /* Kind of use in an unnamed declarator. */
157 abstract_class_use use;
159 /* Position of the declaration. This is only needed for IDENTIFIER_NODEs,
160 because DECLs already carry locus information. */
163 /* Link to the next element in list. */
164 struct pending_abstract_type* next;
167 struct abstract_type_hasher : ggc_hasher<pending_abstract_type *>
169 typedef tree compare_type;
170 static hashval_t hash (pending_abstract_type *);
171 static bool equal (pending_abstract_type *, tree);
174 /* Compute the hash value of the node VAL. This function is used by the
175 hash table abstract_pending_vars. */
178 abstract_type_hasher::hash (pending_abstract_type *pat)
180 return (hashval_t) TYPE_UID (pat->type);
184 /* Compare node VAL1 with the type VAL2. This function is used by the
185 hash table abstract_pending_vars. */
188 abstract_type_hasher::equal (pending_abstract_type *pat1, tree type2)
190 return (pat1->type == type2);
193 /* Hash table that maintains pending_abstract_type nodes, for which we still
194 need to check for type abstractness. The key of the table is the type
195 of the declaration. */
196 static GTY (()) hash_table<abstract_type_hasher> *abstract_pending_vars = NULL;
198 static int abstract_virtuals_error_sfinae (tree, tree, abstract_class_use, tsubst_flags_t);
200 /* This function is called after TYPE is completed, and will check if there
201 are pending declarations for which we still need to verify the abstractness
202 of TYPE, and emit a diagnostic (through abstract_virtuals_error) if TYPE
203 turned out to be incomplete. */
206 complete_type_check_abstract (tree type)
208 struct pending_abstract_type *pat;
209 location_t cur_loc = input_location;
211 gcc_assert (COMPLETE_TYPE_P (type));
213 if (!abstract_pending_vars)
216 /* Retrieve the list of pending declarations for this type. */
217 pending_abstract_type **slot
218 = abstract_pending_vars->find_slot_with_hash (type, TYPE_UID (type),
225 /* If the type is not abstract, do not do anything. */
226 if (CLASSTYPE_PURE_VIRTUALS (type))
228 struct pending_abstract_type *prev = 0, *next;
230 /* Reverse the list to emit the errors in top-down order. */
231 for (; pat; pat = next)
239 /* Go through the list, and call abstract_virtuals_error for each
240 element: it will issue a diagnostic if the type is abstract. */
243 gcc_assert (type == pat->type);
245 /* Tweak input_location so that the diagnostic appears at the correct
246 location. Notice that this is only needed if the decl is an
248 input_location = pat->locus;
249 abstract_virtuals_error_sfinae (pat->decl, pat->type, pat->use,
250 tf_warning_or_error);
255 abstract_pending_vars->clear_slot (slot);
257 input_location = cur_loc;
261 /* If TYPE has abstract virtual functions, issue an error about trying
262 to create an object of that type. DECL is the object declared, or
263 NULL_TREE if the declaration is unavailable, in which case USE specifies
264 the kind of invalid use. Returns 1 if an error occurred; zero if
268 abstract_virtuals_error_sfinae (tree decl, tree type, abstract_class_use use,
269 tsubst_flags_t complain)
271 vec<tree, va_gc> *pure;
273 /* This function applies only to classes. Any other entity can never
275 if (!CLASS_TYPE_P (type))
277 type = TYPE_MAIN_VARIANT (type);
280 /* Instantiation here seems to be required by the standard,
281 but breaks e.g. boost::bind. FIXME! */
282 /* In SFINAE, non-N3276 context, force instantiation. */
283 if (!(complain & (tf_error|tf_decltype)))
284 complete_type (type);
287 /* If the type is incomplete, we register it within a hash table,
288 so that we can check again once it is completed. This makes sense
289 only for objects for which we have a declaration or at least a
291 if (!COMPLETE_TYPE_P (type) && (complain & tf_error))
293 struct pending_abstract_type *pat;
295 gcc_assert (!decl || DECL_P (decl) || identifier_p (decl));
297 if (!abstract_pending_vars)
298 abstract_pending_vars
299 = hash_table<abstract_type_hasher>::create_ggc (31);
301 pending_abstract_type **slot
302 = abstract_pending_vars->find_slot_with_hash (type, TYPE_UID (type),
305 pat = ggc_alloc<pending_abstract_type> ();
309 pat->locus = ((decl && DECL_P (decl))
310 ? DECL_SOURCE_LOCATION (decl)
319 if (!TYPE_SIZE (type))
320 /* TYPE is being defined, and during that time
321 CLASSTYPE_PURE_VIRTUALS holds the inline friends. */
324 pure = CLASSTYPE_PURE_VIRTUALS (type);
328 if (!(complain & tf_error))
334 error ("cannot declare variable %q+D to be of abstract "
335 "type %qT", decl, type);
336 else if (TREE_CODE (decl) == PARM_DECL)
338 if (DECL_NAME (decl))
339 error ("cannot declare parameter %q+D to be of abstract type %qT",
342 error ("cannot declare parameter to be of abstract type %qT",
345 else if (TREE_CODE (decl) == FIELD_DECL)
346 error ("cannot declare field %q+D to be of abstract type %qT",
348 else if (TREE_CODE (decl) == FUNCTION_DECL
349 && TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE)
350 error ("invalid abstract return type for member function %q+#D", decl);
351 else if (TREE_CODE (decl) == FUNCTION_DECL)
352 error ("invalid abstract return type for function %q+#D", decl);
353 else if (identifier_p (decl))
354 /* Here we do not have location information. */
355 error ("invalid abstract type %qT for %qE", type, decl);
357 error ("invalid abstract type for %q+D", decl);
362 error ("creating array of %qT, which is an abstract class type", type);
365 error ("invalid cast to abstract class type %qT", type);
368 error ("invalid new-expression of abstract class type %qT", type);
371 error ("invalid abstract return type %qT", type);
374 error ("invalid abstract parameter type %qT", type);
377 error ("expression of abstract class type %qT cannot "
378 "be used in throw-expression", type);
381 error ("cannot declare catch parameter to be of abstract "
382 "class type %qT", type);
385 error ("cannot allocate an object of abstract type %qT", type);
388 /* Only go through this once. */
394 inform (DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)),
395 " because the following virtual functions are pure within %qT:",
398 FOR_EACH_VEC_ELT (*pure, ix, fn)
399 if (! DECL_CLONED_FUNCTION_P (fn)
400 || DECL_COMPLETE_DESTRUCTOR_P (fn))
401 inform (input_location, "\t%+#D", fn);
403 /* Now truncate the vector. This leaves it non-null, so we know
404 there are pure virtuals, but empty so we don't list them out
413 abstract_virtuals_error_sfinae (tree decl, tree type, tsubst_flags_t complain)
415 return abstract_virtuals_error_sfinae (decl, type, ACU_UNKNOWN, complain);
419 abstract_virtuals_error_sfinae (abstract_class_use use, tree type,
420 tsubst_flags_t complain)
422 return abstract_virtuals_error_sfinae (NULL_TREE, type, use, complain);
426 /* Wrapper for the above function in the common case of wanting errors. */
429 abstract_virtuals_error (tree decl, tree type)
431 return abstract_virtuals_error_sfinae (decl, type, tf_warning_or_error);
435 abstract_virtuals_error (abstract_class_use use, tree type)
437 return abstract_virtuals_error_sfinae (use, type, tf_warning_or_error);
440 /* Print an inform about the declaration of the incomplete type TYPE. */
443 cxx_incomplete_type_inform (const_tree type)
445 if (!TYPE_MAIN_DECL (type))
448 location_t loc = DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type));
449 tree ptype = strip_top_quals (CONST_CAST_TREE (type));
451 if (current_class_type
452 && TYPE_BEING_DEFINED (current_class_type)
453 && same_type_p (ptype, current_class_type))
454 inform (loc, "definition of %q#T is not complete until "
455 "the closing brace", ptype);
456 else if (!TYPE_TEMPLATE_INFO (ptype))
457 inform (loc, "forward declaration of %q#T", ptype);
459 inform (loc, "declaration of %q#T", ptype);
462 /* Print an error message for invalid use of an incomplete type.
463 VALUE is the expression that was used (or 0 if that isn't known)
464 and TYPE is the type that was invalid. DIAG_KIND indicates the
465 type of diagnostic (see diagnostic.def). */
468 cxx_incomplete_type_diagnostic (const_tree value, const_tree type,
469 diagnostic_t diag_kind)
471 bool is_decl = false, complained = false;
473 gcc_assert (diag_kind == DK_WARNING
474 || diag_kind == DK_PEDWARN
475 || diag_kind == DK_ERROR);
477 /* Avoid duplicate error message. */
478 if (TREE_CODE (type) == ERROR_MARK)
481 if (value != 0 && (VAR_P (value)
482 || TREE_CODE (value) == PARM_DECL
483 || TREE_CODE (value) == FIELD_DECL))
485 complained = emit_diagnostic (diag_kind, input_location, 0,
486 "%q+D has incomplete type", value);
490 /* We must print an error message. Be clever about what it says. */
492 switch (TREE_CODE (type))
498 complained = emit_diagnostic (diag_kind, input_location, 0,
499 "invalid use of incomplete type %q#T",
502 cxx_incomplete_type_inform (type);
506 emit_diagnostic (diag_kind, input_location, 0,
507 "invalid use of %qT", type);
511 if (TYPE_DOMAIN (type))
513 type = TREE_TYPE (type);
516 emit_diagnostic (diag_kind, input_location, 0,
517 "invalid use of array with unspecified bounds");
523 tree member = TREE_OPERAND (value, 1);
524 if (is_overloaded_fn (member))
525 member = get_first_fn (member);
526 if (DECL_FUNCTION_MEMBER_P (member)
527 && ! flag_ms_extensions)
528 emit_diagnostic (diag_kind, input_location, 0,
529 "invalid use of member function "
530 "(did you forget the %<()%> ?)");
532 emit_diagnostic (diag_kind, input_location, 0,
533 "invalid use of member "
534 "(did you forget the %<&%> ?)");
538 case TEMPLATE_TYPE_PARM:
540 emit_diagnostic (diag_kind, input_location, 0,
541 "invalid use of %<auto%>");
543 emit_diagnostic (diag_kind, input_location, 0,
544 "invalid use of template type parameter %qT", type);
547 case BOUND_TEMPLATE_TEMPLATE_PARM:
548 emit_diagnostic (diag_kind, input_location, 0,
549 "invalid use of template template parameter %qT",
554 emit_diagnostic (diag_kind, input_location, 0,
555 "invalid use of dependent type %qT", type);
559 if (type == init_list_type_node)
561 emit_diagnostic (diag_kind, input_location, 0,
562 "invalid use of brace-enclosed initializer list");
565 gcc_assert (type == unknown_type_node);
566 if (value && TREE_CODE (value) == COMPONENT_REF)
568 else if (value && TREE_CODE (value) == ADDR_EXPR)
569 emit_diagnostic (diag_kind, input_location, 0,
570 "address of overloaded function with no contextual "
572 else if (value && TREE_CODE (value) == OVERLOAD)
573 emit_diagnostic (diag_kind, input_location, 0,
574 "overloaded function with no contextual type information");
576 emit_diagnostic (diag_kind, input_location, 0,
577 "insufficient contextual information to determine type");
585 /* Backward-compatibility interface to incomplete_type_diagnostic;
586 required by ../tree.c. */
587 #undef cxx_incomplete_type_error
589 cxx_incomplete_type_error (const_tree value, const_tree type)
591 cxx_incomplete_type_diagnostic (value, type, DK_ERROR);
595 /* The recursive part of split_nonconstant_init. DEST is an lvalue
596 expression to which INIT should be assigned. INIT is a CONSTRUCTOR.
597 Return true if the whole of the value was initialized by the
598 generated statements. */
601 split_nonconstant_init_1 (tree dest, tree init)
603 unsigned HOST_WIDE_INT idx;
604 tree field_index, value;
605 tree type = TREE_TYPE (dest);
606 tree inner_type = NULL;
607 bool array_type_p = false;
608 bool complete_p = true;
609 HOST_WIDE_INT num_split_elts = 0;
611 switch (TREE_CODE (type))
614 inner_type = TREE_TYPE (type);
616 if ((TREE_SIDE_EFFECTS (init)
617 && TYPE_HAS_NONTRIVIAL_DESTRUCTOR (type))
618 || array_of_runtime_bound_p (type))
620 /* For an array, we only need/want a single cleanup region rather
621 than one per element. */
622 tree code = build_vec_init (dest, NULL_TREE, init, false, 1,
623 tf_warning_or_error);
631 case QUAL_UNION_TYPE:
632 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (init), idx,
635 /* The current implementation of this algorithm assumes that
636 the field was set for all the elements. This is usually done
637 by process_init_constructor. */
638 gcc_assert (field_index);
641 inner_type = TREE_TYPE (field_index);
643 if (TREE_CODE (value) == CONSTRUCTOR)
648 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
649 NULL_TREE, NULL_TREE);
651 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
654 if (!split_nonconstant_init_1 (sub, value))
657 CONSTRUCTOR_ELTS (init)->ordered_remove (idx--);
660 else if (!initializer_constant_valid_p (value, inner_type))
665 /* FIXME: Ordered removal is O(1) so the whole function is
666 worst-case quadratic. This could be fixed using an aside
667 bitmap to record which elements must be removed and remove
668 them all at the same time. Or by merging
669 split_non_constant_init into process_init_constructor_array,
670 that is separating constants from non-constants while building
672 CONSTRUCTOR_ELTS (init)->ordered_remove (idx);
675 if (TREE_CODE (field_index) == RANGE_EXPR)
677 /* Use build_vec_init to initialize a range. */
678 tree low = TREE_OPERAND (field_index, 0);
679 tree hi = TREE_OPERAND (field_index, 1);
680 sub = build4 (ARRAY_REF, inner_type, dest, low,
681 NULL_TREE, NULL_TREE);
682 sub = cp_build_addr_expr (sub, tf_warning_or_error);
683 tree max = size_binop (MINUS_EXPR, hi, low);
684 code = build_vec_init (sub, max, value, false, 0,
685 tf_warning_or_error);
687 if (tree_fits_shwi_p (max))
688 num_split_elts += tree_to_shwi (max);
693 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
694 NULL_TREE, NULL_TREE);
696 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
699 code = build2 (INIT_EXPR, inner_type, sub, value);
700 code = build_stmt (input_location, EXPR_STMT, code);
701 code = maybe_cleanup_point_expr_void (code);
703 if (type_build_dtor_call (inner_type))
705 code = (build_special_member_call
706 (sub, complete_dtor_identifier, NULL, inner_type,
707 LOOKUP_NORMAL, tf_warning_or_error));
708 if (!TYPE_HAS_TRIVIAL_DESTRUCTOR (inner_type))
709 finish_eh_cleanup (code);
719 if (!initializer_constant_valid_p (init, type))
722 tree cons = copy_node (init);
723 CONSTRUCTOR_ELTS (init) = NULL;
724 code = build2 (MODIFY_EXPR, type, dest, cons);
725 code = build_stmt (input_location, EXPR_STMT, code);
727 num_split_elts += CONSTRUCTOR_NELTS (init);
735 /* The rest of the initializer is now a constant. */
736 TREE_CONSTANT (init) = 1;
737 return complete_p && complete_ctor_at_level_p (TREE_TYPE (init),
738 num_split_elts, inner_type);
741 /* A subroutine of store_init_value. Splits non-constant static
742 initializer INIT into a constant part and generates code to
743 perform the non-constant part of the initialization to DEST.
744 Returns the code for the runtime init. */
747 split_nonconstant_init (tree dest, tree init)
751 if (TREE_CODE (init) == TARGET_EXPR)
752 init = TARGET_EXPR_INITIAL (init);
753 if (TREE_CODE (init) == CONSTRUCTOR)
755 code = push_stmt_list ();
756 if (split_nonconstant_init_1 (dest, init))
758 code = pop_stmt_list (code);
759 DECL_INITIAL (dest) = init;
760 TREE_READONLY (dest) = 0;
763 code = build2 (INIT_EXPR, TREE_TYPE (dest), dest, init);
768 /* Perform appropriate conversions on the initial value of a variable,
769 store it in the declaration DECL,
770 and print any error messages that are appropriate.
771 If the init is invalid, store an ERROR_MARK.
773 C++: Note that INIT might be a TREE_LIST, which would mean that it is
774 a base class initializer for some aggregate type, hopefully compatible
775 with DECL. If INIT is a single element, and DECL is an aggregate
776 type, we silently convert INIT into a TREE_LIST, allowing a constructor
779 If INIT is a TREE_LIST and there is no constructor, turn INIT
780 into a CONSTRUCTOR and use standard initialization techniques.
781 Perhaps a warning should be generated?
783 Returns code to be executed if initialization could not be performed
784 for static variable. In that case, caller must emit the code. */
787 store_init_value (tree decl, tree init, vec<tree, va_gc>** cleanups, int flags)
791 /* If variable's type was invalidly declared, just ignore it. */
793 type = TREE_TYPE (decl);
794 if (TREE_CODE (type) == ERROR_MARK)
797 if (MAYBE_CLASS_TYPE_P (type))
799 if (TREE_CODE (init) == TREE_LIST)
801 error ("constructor syntax used, but no constructor declared "
802 "for type %qT", type);
803 init = build_constructor_from_list (init_list_type_node, nreverse (init));
807 /* End of special C++ code. */
809 if (flags & LOOKUP_ALREADY_DIGESTED)
812 /* Digest the specified initializer into an expression. */
813 value = digest_init_flags (type, init, flags);
815 value = extend_ref_init_temps (decl, value, cleanups);
817 /* In C++11 constant expression is a semantic, not syntactic, property.
818 In C++98, make sure that what we thought was a constant expression at
819 template definition time is still constant and otherwise perform this
820 as optimization, e.g. to fold SIZEOF_EXPRs in the initializer. */
821 if (decl_maybe_constant_var_p (decl) || TREE_STATIC (decl))
824 value = instantiate_non_dependent_expr (value);
825 if (DECL_DECLARED_CONSTEXPR_P (decl)
826 || DECL_IN_AGGR_P (decl))
828 /* Diagnose a non-constant initializer for constexpr. */
829 if (processing_template_decl
830 && !require_potential_constant_expression (value))
831 value = error_mark_node;
833 value = cxx_constant_value (value, decl);
835 value = maybe_constant_init (value, decl);
836 if (TREE_CODE (value) == CONSTRUCTOR && cp_has_mutable_p (type))
837 /* Poison this CONSTRUCTOR so it can't be copied to another
838 constexpr variable. */
839 CONSTRUCTOR_MUTABLE_POISON (value) = true;
840 const_init = (reduced_constant_expression_p (value)
841 || error_operand_p (value));
842 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = const_init;
843 TREE_CONSTANT (decl) = const_init && decl_maybe_constant_var_p (decl);
846 if (cxx_dialect >= cxx14 && CLASS_TYPE_P (strip_array_types (type)))
847 /* Handle aggregate NSDMI in non-constant initializers, too. */
848 value = replace_placeholders (value, decl);
850 /* If the initializer is not a constant, fill in DECL_INITIAL with
851 the bits that are constant, and then return an expression that
852 will perform the dynamic initialization. */
853 if (value != error_mark_node
854 && (TREE_SIDE_EFFECTS (value)
855 || array_of_runtime_bound_p (type)
856 || ! reduced_constant_expression_p (value)))
857 return split_nonconstant_init (decl, value);
858 /* If the value is a constant, just put it in DECL_INITIAL. If DECL
859 is an automatic variable, the middle end will turn this into a
860 dynamic initialization later. */
861 DECL_INITIAL (decl) = value;
866 /* Give diagnostic about narrowing conversions within { }. */
869 check_narrowing (tree type, tree init, tsubst_flags_t complain)
871 tree ftype = unlowered_expr_type (init);
875 if (((!warn_narrowing || !(complain & tf_warning))
876 && cxx_dialect == cxx98)
877 || !ARITHMETIC_TYPE_P (type))
880 if (BRACE_ENCLOSED_INITIALIZER_P (init)
881 && TREE_CODE (type) == COMPLEX_TYPE)
883 tree elttype = TREE_TYPE (type);
884 if (CONSTRUCTOR_NELTS (init) > 0)
885 ok &= check_narrowing (elttype, CONSTRUCTOR_ELT (init, 0)->value,
887 if (CONSTRUCTOR_NELTS (init) > 1)
888 ok &= check_narrowing (elttype, CONSTRUCTOR_ELT (init, 1)->value,
893 init = fold_non_dependent_expr (init);
895 if (TREE_CODE (type) == INTEGER_TYPE
896 && TREE_CODE (ftype) == REAL_TYPE)
898 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
899 && CP_INTEGRAL_TYPE_P (type))
901 if (TREE_CODE (ftype) == ENUMERAL_TYPE)
902 /* Check for narrowing based on the values of the enumeration. */
903 ftype = ENUM_UNDERLYING_TYPE (ftype);
904 if ((tree_int_cst_lt (TYPE_MAX_VALUE (type),
905 TYPE_MAX_VALUE (ftype))
906 || tree_int_cst_lt (TYPE_MIN_VALUE (ftype),
907 TYPE_MIN_VALUE (type)))
908 && (TREE_CODE (init) != INTEGER_CST
909 || !int_fits_type_p (init, type)))
912 else if (TREE_CODE (ftype) == REAL_TYPE
913 && TREE_CODE (type) == REAL_TYPE)
915 if (TYPE_PRECISION (type) < TYPE_PRECISION (ftype))
917 if (TREE_CODE (init) == REAL_CST)
919 /* Issue 703: Loss of precision is OK as long as the value is
920 within the representable range of the new type. */
922 d = TREE_REAL_CST (init);
923 real_convert (&r, TYPE_MODE (type), &d);
931 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
932 && TREE_CODE (type) == REAL_TYPE)
935 if (TREE_CODE (init) == INTEGER_CST)
937 d = real_value_from_int_cst (0, init);
938 if (exact_real_truncate (TYPE_MODE (type), &d))
945 if (cxx_dialect == cxx98)
946 warning_at (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
947 "narrowing conversion of %qE from %qT to %qT inside { } "
948 "is ill-formed in C++11", init, ftype, type);
949 else if (!TREE_CONSTANT (init))
951 if (complain & tf_warning_or_error)
953 pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
954 "narrowing conversion of %qE from %qT to %qT inside { }",
959 else if (complain & tf_error)
961 int savederrorcount = errorcount;
962 global_dc->pedantic_errors = 1;
963 pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
964 "narrowing conversion of %qE from %qT to %qT "
965 "inside { }", init, ftype, type);
966 if (errorcount == savederrorcount)
968 global_dc->pedantic_errors = flag_pedantic_errors;
972 return cxx_dialect == cxx98 || ok;
975 /* Process the initializer INIT for a variable of type TYPE, emitting
976 diagnostics for invalid initializers and converting the initializer as
979 For aggregate types, it assumes that reshape_init has already run, thus the
980 initializer will have the right shape (brace elision has been undone).
982 NESTED is true iff we are being called for an element of a CONSTRUCTOR. */
985 digest_init_r (tree type, tree init, bool nested, int flags,
986 tsubst_flags_t complain)
988 enum tree_code code = TREE_CODE (type);
990 if (error_operand_p (init))
991 return error_mark_node;
995 /* We must strip the outermost array type when completing the type,
996 because the its bounds might be incomplete at the moment. */
997 if (!complete_type_or_maybe_complain (TREE_CODE (type) == ARRAY_TYPE
998 ? TREE_TYPE (type) : type, NULL_TREE,
1000 return error_mark_node;
1002 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue
1003 (g++.old-deja/g++.law/casts2.C). */
1004 if (TREE_CODE (init) == NON_LVALUE_EXPR)
1005 init = TREE_OPERAND (init, 0);
1007 /* Initialization of an array of chars from a string constant. The initializer
1008 can be optionally enclosed in braces, but reshape_init has already removed
1009 them if they were present. */
1010 if (code == ARRAY_TYPE)
1012 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
1013 if (char_type_p (typ1)
1015 && TREE_CODE (init) == STRING_CST)
1017 tree char_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (init)));
1019 if (TYPE_PRECISION (typ1) == BITS_PER_UNIT)
1021 if (char_type != char_type_node)
1023 if (complain & tf_error)
1024 error ("char-array initialized from wide string");
1025 return error_mark_node;
1030 if (char_type == char_type_node)
1032 if (complain & tf_error)
1033 error ("int-array initialized from non-wide string");
1034 return error_mark_node;
1036 else if (char_type != typ1)
1038 if (complain & tf_error)
1039 error ("int-array initialized from incompatible "
1041 return error_mark_node;
1045 if (type != TREE_TYPE (init))
1047 init = copy_node (init);
1048 TREE_TYPE (init) = type;
1050 if (TYPE_DOMAIN (type) != 0 && TREE_CONSTANT (TYPE_SIZE (type)))
1052 int size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1053 size = (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1054 /* In C it is ok to subtract 1 from the length of the string
1055 because it's ok to ignore the terminating null char that is
1056 counted in the length of the constant, but in C++ this would
1058 if (size < TREE_STRING_LENGTH (init))
1059 permerror (input_location, "initializer-string for array "
1060 "of chars is too long");
1066 /* Handle scalar types (including conversions) and references. */
1067 if ((TREE_CODE (type) != COMPLEX_TYPE
1068 || BRACE_ENCLOSED_INITIALIZER_P (init))
1069 && (SCALAR_TYPE_P (type) || code == REFERENCE_TYPE))
1074 flags |= LOOKUP_NO_NARROWING;
1075 init = convert_for_initialization (0, type, init, flags,
1076 ICR_INIT, NULL_TREE, 0,
1080 /* Skip any conversions since we'll be outputting the underlying
1082 while (CONVERT_EXPR_P (*exp)
1083 || TREE_CODE (*exp) == NON_LVALUE_EXPR)
1084 exp = &TREE_OPERAND (*exp, 0);
1086 *exp = cplus_expand_constant (*exp);
1091 /* Come here only for aggregates: records, arrays, unions, complex numbers
1093 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
1094 || TREE_CODE (type) == VECTOR_TYPE
1095 || TREE_CODE (type) == RECORD_TYPE
1096 || TREE_CODE (type) == UNION_TYPE
1097 || TREE_CODE (type) == COMPLEX_TYPE);
1099 /* "If T is a class type and the initializer list has a single
1100 element of type cv U, where U is T or a class derived from T,
1101 the object is initialized from that element." */
1102 if (cxx_dialect >= cxx11
1103 && BRACE_ENCLOSED_INITIALIZER_P (init)
1104 && CONSTRUCTOR_NELTS (init) == 1
1105 && (CLASS_TYPE_P (type) || VECTOR_TYPE_P (type)))
1107 tree elt = CONSTRUCTOR_ELT (init, 0)->value;
1108 if (reference_related_p (type, TREE_TYPE (elt)))
1112 if (BRACE_ENCLOSED_INITIALIZER_P (init)
1113 && !TYPE_NON_AGGREGATE_CLASS (type))
1114 return process_init_constructor (type, init, complain);
1117 if (COMPOUND_LITERAL_P (init) && TREE_CODE (type) == ARRAY_TYPE)
1119 if (complain & tf_error)
1120 error ("cannot initialize aggregate of type %qT with "
1121 "a compound literal", type);
1123 return error_mark_node;
1126 if (TREE_CODE (type) == ARRAY_TYPE
1127 && !BRACE_ENCLOSED_INITIALIZER_P (init))
1129 /* Allow the result of build_array_copy and of
1130 build_value_init_noctor. */
1131 if ((TREE_CODE (init) == VEC_INIT_EXPR
1132 || TREE_CODE (init) == CONSTRUCTOR)
1133 && (same_type_ignoring_top_level_qualifiers_p
1134 (type, TREE_TYPE (init))))
1137 if (complain & tf_error)
1138 error ("array must be initialized with a brace-enclosed"
1140 return error_mark_node;
1143 return convert_for_initialization (NULL_TREE, type, init,
1145 ICR_INIT, NULL_TREE, 0,
1151 digest_init (tree type, tree init, tsubst_flags_t complain)
1153 return digest_init_r (type, init, false, LOOKUP_IMPLICIT, complain);
1157 digest_init_flags (tree type, tree init, int flags)
1159 return digest_init_r (type, init, false, flags, tf_warning_or_error);
1162 /* Process the initializer INIT for an NSDMI DECL (a FIELD_DECL). */
1164 digest_nsdmi_init (tree decl, tree init)
1166 gcc_assert (TREE_CODE (decl) == FIELD_DECL);
1168 int flags = LOOKUP_IMPLICIT;
1169 if (DIRECT_LIST_INIT_P (init))
1170 flags = LOOKUP_NORMAL;
1171 init = digest_init_flags (TREE_TYPE (decl), init, flags);
1172 if (TREE_CODE (init) == TARGET_EXPR)
1173 /* This represents the whole initialization. */
1174 TARGET_EXPR_DIRECT_INIT_P (init) = true;
1178 /* Set of flags used within process_init_constructor to describe the
1180 #define PICFLAG_ERRONEOUS 1
1181 #define PICFLAG_NOT_ALL_CONSTANT 2
1182 #define PICFLAG_NOT_ALL_SIMPLE 4
1183 #define PICFLAG_SIDE_EFFECTS 8
1185 /* Given an initializer INIT, return the flag (PICFLAG_*) which better
1189 picflag_from_initializer (tree init)
1191 if (init == error_mark_node)
1192 return PICFLAG_ERRONEOUS;
1193 else if (!TREE_CONSTANT (init))
1195 if (TREE_SIDE_EFFECTS (init))
1196 return PICFLAG_SIDE_EFFECTS;
1198 return PICFLAG_NOT_ALL_CONSTANT;
1200 else if (!initializer_constant_valid_p (init, TREE_TYPE (init)))
1201 return PICFLAG_NOT_ALL_SIMPLE;
1205 /* Adjust INIT for going into a CONSTRUCTOR. */
1208 massage_init_elt (tree type, tree init, tsubst_flags_t complain)
1210 init = digest_init_r (type, init, true, LOOKUP_IMPLICIT, complain);
1211 /* Strip a simple TARGET_EXPR when we know this is an initializer. */
1212 if (TREE_CODE (init) == TARGET_EXPR
1213 && !VOID_TYPE_P (TREE_TYPE (TARGET_EXPR_INITIAL (init))))
1214 init = TARGET_EXPR_INITIAL (init);
1215 /* When we defer constant folding within a statement, we may want to
1216 defer this folding as well. */
1217 tree t = fold_non_dependent_expr (init);
1218 t = maybe_constant_init (t);
1219 if (TREE_CONSTANT (t))
1224 /* Subroutine of process_init_constructor, which will process an initializer
1225 INIT for an array or vector of type TYPE. Returns the flags (PICFLAG_*)
1226 which describe the initializers. */
1229 process_init_constructor_array (tree type, tree init,
1230 tsubst_flags_t complain)
1232 unsigned HOST_WIDE_INT i, len = 0;
1234 bool unbounded = false;
1235 constructor_elt *ce;
1236 vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (init);
1238 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
1239 || TREE_CODE (type) == VECTOR_TYPE);
1241 if (TREE_CODE (type) == ARRAY_TYPE)
1243 tree domain = TYPE_DOMAIN (type);
1244 if (domain && TREE_CONSTANT (TYPE_MAX_VALUE (domain)))
1245 len = wi::ext (wi::to_offset (TYPE_MAX_VALUE (domain))
1246 - wi::to_offset (TYPE_MIN_VALUE (domain)) + 1,
1247 TYPE_PRECISION (TREE_TYPE (domain)),
1248 TYPE_SIGN (TREE_TYPE (domain))).to_uhwi ();
1250 unbounded = true; /* Take as many as there are. */
1253 /* Vectors are like simple fixed-size arrays. */
1254 len = TYPE_VECTOR_SUBPARTS (type);
1256 /* There must not be more initializers than needed. */
1257 if (!unbounded && vec_safe_length (v) > len)
1259 if (complain & tf_error)
1260 error ("too many initializers for %qT", type);
1262 return PICFLAG_ERRONEOUS;
1265 FOR_EACH_VEC_SAFE_ELT (v, i, ce)
1269 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST);
1270 if (compare_tree_int (ce->index, i) != 0)
1272 ce->value = error_mark_node;
1273 sorry ("non-trivial designated initializers not supported");
1277 ce->index = size_int (i);
1278 gcc_assert (ce->value);
1279 ce->value = massage_init_elt (TREE_TYPE (type), ce->value, complain);
1281 if (ce->value != error_mark_node)
1282 gcc_assert (same_type_ignoring_top_level_qualifiers_p
1283 (TREE_TYPE (type), TREE_TYPE (ce->value)));
1285 flags |= picflag_from_initializer (ce->value);
1288 /* No more initializers. If the array is unbounded, we are done. Otherwise,
1289 we must add initializers ourselves. */
1291 for (; i < len; ++i)
1295 if (type_build_ctor_call (TREE_TYPE (type)))
1297 /* If this type needs constructors run for default-initialization,
1298 we can't rely on the back end to do it for us, so make the
1299 initialization explicit by list-initializing from T{}. */
1300 next = build_constructor (init_list_type_node, NULL);
1301 CONSTRUCTOR_IS_DIRECT_INIT (next) = true;
1302 next = massage_init_elt (TREE_TYPE (type), next, complain);
1303 if (initializer_zerop (next))
1304 /* The default zero-initialization is fine for us; don't
1305 add anything to the CONSTRUCTOR. */
1308 else if (!zero_init_p (TREE_TYPE (type)))
1309 next = build_zero_init (TREE_TYPE (type),
1310 /*nelts=*/NULL_TREE,
1311 /*static_storage_p=*/false);
1313 /* The default zero-initialization is fine for us; don't
1314 add anything to the CONSTRUCTOR. */
1319 flags |= picflag_from_initializer (next);
1320 CONSTRUCTOR_APPEND_ELT (v, size_int (i), next);
1324 CONSTRUCTOR_ELTS (init) = v;
1328 /* Subroutine of process_init_constructor, which will process an initializer
1329 INIT for a class of type TYPE. Returns the flags (PICFLAG_*) which describe
1330 the initializers. */
1333 process_init_constructor_record (tree type, tree init,
1334 tsubst_flags_t complain)
1336 vec<constructor_elt, va_gc> *v = NULL;
1340 gcc_assert (TREE_CODE (type) == RECORD_TYPE);
1341 gcc_assert (!CLASSTYPE_VBASECLASSES (type));
1342 gcc_assert (!TYPE_BINFO (type)
1343 || !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)));
1344 gcc_assert (!TYPE_POLYMORPHIC_P (type));
1348 unsigned HOST_WIDE_INT idx = 0;
1349 /* Generally, we will always have an index for each initializer (which is
1350 a FIELD_DECL, put by reshape_init), but compound literals don't go trough
1351 reshape_init. So we need to handle both cases. */
1352 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
1357 if (!DECL_NAME (field) && DECL_C_BIT_FIELD (field))
1360 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1363 /* If this is a bitfield, first convert to the declared type. */
1364 type = TREE_TYPE (field);
1365 if (DECL_BIT_FIELD_TYPE (field))
1366 type = DECL_BIT_FIELD_TYPE (field);
1367 if (type == error_mark_node)
1368 return PICFLAG_ERRONEOUS;
1370 if (idx < vec_safe_length (CONSTRUCTOR_ELTS (init)))
1372 constructor_elt *ce = &(*CONSTRUCTOR_ELTS (init))[idx];
1375 /* We can have either a FIELD_DECL or an IDENTIFIER_NODE. The
1376 latter case can happen in templates where lookup has to be
1378 gcc_assert (TREE_CODE (ce->index) == FIELD_DECL
1379 || identifier_p (ce->index));
1380 if (ce->index != field
1381 && ce->index != DECL_NAME (field))
1383 ce->value = error_mark_node;
1384 sorry ("non-trivial designated initializers not supported");
1388 gcc_assert (ce->value);
1389 next = massage_init_elt (type, ce->value, complain);
1392 else if (DECL_INITIAL (field))
1396 /* We're using an NSDMI past a field with implicit
1397 zero-init. Go back and make it explicit. */
1399 vec_safe_truncate (v, 0);
1402 /* C++14 aggregate NSDMI. */
1403 next = get_nsdmi (field, /*ctor*/false);
1405 else if (type_build_ctor_call (TREE_TYPE (field)))
1407 /* If this type needs constructors run for
1408 default-initialization, we can't rely on the back end to do it
1409 for us, so build up TARGET_EXPRs. If the type in question is
1410 a class, just build one up; if it's an array, recurse. */
1411 next = build_constructor (init_list_type_node, NULL);
1412 /* Call this direct-initialization pending DR 1518 resolution so
1413 that explicit default ctors don't break valid C++03 code. */
1414 CONSTRUCTOR_IS_DIRECT_INIT (next) = true;
1415 next = massage_init_elt (TREE_TYPE (field), next, complain);
1417 /* Warn when some struct elements are implicitly initialized. */
1418 if ((complain & tf_warning)
1419 && !EMPTY_CONSTRUCTOR_P (init))
1420 warning (OPT_Wmissing_field_initializers,
1421 "missing initializer for member %qD", field);
1425 if (TREE_CODE (TREE_TYPE (field)) == REFERENCE_TYPE)
1427 if (complain & tf_error)
1428 error ("member %qD is uninitialized reference", field);
1430 return PICFLAG_ERRONEOUS;
1432 else if (CLASSTYPE_REF_FIELDS_NEED_INIT (TREE_TYPE (field)))
1434 if (complain & tf_error)
1435 error ("member %qD with uninitialized reference fields", field);
1437 return PICFLAG_ERRONEOUS;
1440 /* Warn when some struct elements are implicitly initialized
1442 if ((complain & tf_warning)
1443 && !EMPTY_CONSTRUCTOR_P (init))
1444 warning (OPT_Wmissing_field_initializers,
1445 "missing initializer for member %qD", field);
1447 if (!zero_init_p (TREE_TYPE (field))
1449 next = build_zero_init (TREE_TYPE (field), /*nelts=*/NULL_TREE,
1450 /*static_storage_p=*/false);
1453 /* The default zero-initialization is fine for us; don't
1454 add anything to the CONSTRUCTOR. */
1460 /* If this is a bitfield, now convert to the lowered type. */
1461 if (type != TREE_TYPE (field))
1462 next = cp_convert_and_check (TREE_TYPE (field), next, complain);
1463 flags |= picflag_from_initializer (next);
1464 CONSTRUCTOR_APPEND_ELT (v, field, next);
1467 if (idx < vec_safe_length (CONSTRUCTOR_ELTS (init)))
1469 if (complain & tf_error)
1470 error ("too many initializers for %qT", type);
1472 return PICFLAG_ERRONEOUS;
1475 CONSTRUCTOR_ELTS (init) = v;
1479 /* Subroutine of process_init_constructor, which will process a single
1480 initializer INIT for a union of type TYPE. Returns the flags (PICFLAG_*)
1481 which describe the initializer. */
1484 process_init_constructor_union (tree type, tree init,
1485 tsubst_flags_t complain)
1487 constructor_elt *ce;
1490 /* If the initializer was empty, use default zero initialization. */
1491 if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
1494 len = CONSTRUCTOR_ELTS (init)->length ();
1497 if (!(complain & tf_error))
1498 return PICFLAG_ERRONEOUS;
1499 error ("too many initializers for %qT", type);
1500 CONSTRUCTOR_ELTS (init)->block_remove (1, len-1);
1503 ce = &(*CONSTRUCTOR_ELTS (init))[0];
1505 /* If this element specifies a field, initialize via that field. */
1508 if (TREE_CODE (ce->index) == FIELD_DECL)
1510 else if (identifier_p (ce->index))
1512 /* This can happen within a cast, see g++.dg/opt/cse2.C. */
1513 tree name = ce->index;
1515 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1516 if (DECL_NAME (field) == name)
1520 if (complain & tf_error)
1521 error ("no field %qD found in union being initialized",
1523 ce->value = error_mark_node;
1529 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST
1530 || TREE_CODE (ce->index) == RANGE_EXPR);
1531 if (complain & tf_error)
1532 error ("index value instead of field name in union initializer");
1533 ce->value = error_mark_node;
1538 /* Find the first named field. ANSI decided in September 1990
1539 that only named fields count here. */
1540 tree field = TYPE_FIELDS (type);
1541 while (field && (!DECL_NAME (field) || TREE_CODE (field) != FIELD_DECL))
1542 field = TREE_CHAIN (field);
1543 if (field == NULL_TREE)
1545 if (complain & tf_error)
1546 error ("too many initializers for %qT", type);
1547 ce->value = error_mark_node;
1552 if (ce->value && ce->value != error_mark_node)
1553 ce->value = massage_init_elt (TREE_TYPE (ce->index), ce->value, complain);
1555 return picflag_from_initializer (ce->value);
1558 /* Process INIT, a constructor for a variable of aggregate type TYPE. The
1559 constructor is a brace-enclosed initializer, and will be modified in-place.
1561 Each element is converted to the right type through digest_init, and
1562 missing initializers are added following the language rules (zero-padding,
1565 After the execution, the initializer will have TREE_CONSTANT if all elts are
1566 constant, and TREE_STATIC set if, in addition, all elts are simple enough
1567 constants that the assembler and linker can compute them.
1569 The function returns the initializer itself, or error_mark_node in case
1573 process_init_constructor (tree type, tree init, tsubst_flags_t complain)
1577 gcc_assert (BRACE_ENCLOSED_INITIALIZER_P (init));
1579 if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1580 flags = process_init_constructor_array (type, init, complain);
1581 else if (TREE_CODE (type) == RECORD_TYPE)
1582 flags = process_init_constructor_record (type, init, complain);
1583 else if (TREE_CODE (type) == UNION_TYPE)
1584 flags = process_init_constructor_union (type, init, complain);
1588 if (flags & PICFLAG_ERRONEOUS)
1589 return error_mark_node;
1591 TREE_TYPE (init) = type;
1592 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == NULL_TREE)
1593 cp_complete_array_type (&TREE_TYPE (init), init, /*do_default=*/0);
1594 if (flags & PICFLAG_SIDE_EFFECTS)
1596 TREE_CONSTANT (init) = false;
1597 TREE_SIDE_EFFECTS (init) = true;
1599 else if (flags & PICFLAG_NOT_ALL_CONSTANT)
1600 /* Make sure TREE_CONSTANT isn't set from build_constructor. */
1601 TREE_CONSTANT (init) = false;
1604 TREE_CONSTANT (init) = 1;
1605 if (!(flags & PICFLAG_NOT_ALL_SIMPLE))
1606 TREE_STATIC (init) = 1;
1611 /* Given a structure or union value DATUM, construct and return
1612 the structure or union component which results from narrowing
1613 that value to the base specified in BASETYPE. For example, given the
1616 class L { int ii; };
1617 class A : L { ... };
1618 class B : L { ... };
1619 class C : A, B { ... };
1627 x.A::ii refers to the ii member of the L part of
1628 the A part of the C object named by X. In this case,
1629 DATUM would be x, and BASETYPE would be A.
1631 I used to think that this was nonconformant, that the standard specified
1632 that first we look up ii in A, then convert x to an L& and pull out the
1633 ii part. But in fact, it does say that we convert x to an A&; A here
1634 is known as the "naming class". (jason 2000-12-19)
1636 BINFO_P points to a variable initialized either to NULL_TREE or to the
1637 binfo for the specific base subobject we want to convert to. */
1640 build_scoped_ref (tree datum, tree basetype, tree* binfo_p)
1644 if (datum == error_mark_node)
1645 return error_mark_node;
1649 binfo = lookup_base (TREE_TYPE (datum), basetype, ba_check,
1650 NULL, tf_warning_or_error);
1652 if (!binfo || binfo == error_mark_node)
1654 *binfo_p = NULL_TREE;
1656 error_not_base_type (basetype, TREE_TYPE (datum));
1657 return error_mark_node;
1661 return build_base_path (PLUS_EXPR, datum, binfo, 1,
1662 tf_warning_or_error);
1665 /* Build a reference to an object specified by the C++ `->' operator.
1666 Usually this just involves dereferencing the object, but if the
1667 `->' operator is overloaded, then such overloads must be
1668 performed until an object which does not have the `->' operator
1669 overloaded is found. An error is reported when circular pointer
1670 delegation is detected. */
1673 build_x_arrow (location_t loc, tree expr, tsubst_flags_t complain)
1675 tree orig_expr = expr;
1676 tree type = TREE_TYPE (expr);
1677 tree last_rval = NULL_TREE;
1678 vec<tree, va_gc> *types_memoized = NULL;
1680 if (type == error_mark_node)
1681 return error_mark_node;
1683 if (processing_template_decl)
1685 if (type_dependent_expression_p (expr))
1686 return build_min_nt_loc (loc, ARROW_EXPR, expr);
1687 expr = build_non_dependent_expr (expr);
1690 if (MAYBE_CLASS_TYPE_P (type))
1692 struct tinst_level *actual_inst = current_instantiation ();
1695 while ((expr = build_new_op (loc, COMPONENT_REF,
1696 LOOKUP_NORMAL, expr, NULL_TREE, NULL_TREE,
1699 if (expr == error_mark_node)
1700 return error_mark_node;
1702 /* This provides a better instantiation backtrace in case of
1704 if (fn && DECL_USE_TEMPLATE (fn))
1705 push_tinst_level_loc (fn,
1706 (current_instantiation () != actual_inst)
1707 ? DECL_SOURCE_LOCATION (fn)
1711 if (vec_member (TREE_TYPE (expr), types_memoized))
1713 if (complain & tf_error)
1714 error ("circular pointer delegation detected");
1715 return error_mark_node;
1718 vec_safe_push (types_memoized, TREE_TYPE (expr));
1722 while (current_instantiation () != actual_inst)
1725 if (last_rval == NULL_TREE)
1727 if (complain & tf_error)
1728 error ("base operand of %<->%> has non-pointer type %qT", type);
1729 return error_mark_node;
1732 if (TREE_CODE (TREE_TYPE (last_rval)) == REFERENCE_TYPE)
1733 last_rval = convert_from_reference (last_rval);
1736 last_rval = decay_conversion (expr, complain);
1738 if (TYPE_PTR_P (TREE_TYPE (last_rval)))
1740 if (processing_template_decl)
1742 expr = build_min (ARROW_EXPR, TREE_TYPE (TREE_TYPE (last_rval)),
1744 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (last_rval);
1748 return cp_build_indirect_ref (last_rval, RO_NULL, complain);
1751 if (complain & tf_error)
1754 error ("result of %<operator->()%> yields non-pointer result");
1756 error ("base operand of %<->%> is not a pointer");
1758 return error_mark_node;
1761 /* Return an expression for "DATUM .* COMPONENT". DATUM has not
1762 already been checked out to be of aggregate type. */
1765 build_m_component_ref (tree datum, tree component, tsubst_flags_t complain)
1773 if (error_operand_p (datum) || error_operand_p (component))
1774 return error_mark_node;
1776 datum = mark_lvalue_use (datum);
1777 component = mark_rvalue_use (component);
1779 ptrmem_type = TREE_TYPE (component);
1780 if (!TYPE_PTRMEM_P (ptrmem_type))
1782 if (complain & tf_error)
1783 error ("%qE cannot be used as a member pointer, since it is of "
1784 "type %qT", component, ptrmem_type);
1785 return error_mark_node;
1788 objtype = TYPE_MAIN_VARIANT (TREE_TYPE (datum));
1789 if (! MAYBE_CLASS_TYPE_P (objtype))
1791 if (complain & tf_error)
1792 error ("cannot apply member pointer %qE to %qE, which is of "
1793 "non-class type %qT", component, datum, objtype);
1794 return error_mark_node;
1797 type = TYPE_PTRMEM_POINTED_TO_TYPE (ptrmem_type);
1798 ctype = complete_type (TYPE_PTRMEM_CLASS_TYPE (ptrmem_type));
1800 if (!COMPLETE_TYPE_P (ctype))
1802 if (!same_type_p (ctype, objtype))
1808 binfo = lookup_base (objtype, ctype, ba_check, NULL, complain);
1813 if (complain & tf_error)
1814 error ("pointer to member type %qT incompatible with object "
1815 "type %qT", type, objtype);
1816 return error_mark_node;
1818 else if (binfo == error_mark_node)
1819 return error_mark_node;
1822 if (TYPE_PTRDATAMEM_P (ptrmem_type))
1824 cp_lvalue_kind kind = lvalue_kind (datum);
1827 /* Compute the type of the field, as described in [expr.ref].
1828 There's no such thing as a mutable pointer-to-member, so
1829 things are not as complex as they are for references to
1830 non-static data members. */
1831 type = cp_build_qualified_type (type,
1832 (cp_type_quals (type)
1833 | cp_type_quals (TREE_TYPE (datum))));
1835 datum = build_address (datum);
1837 /* Convert object to the correct base. */
1840 datum = build_base_path (PLUS_EXPR, datum, binfo, 1, complain);
1841 if (datum == error_mark_node)
1842 return error_mark_node;
1845 /* Build an expression for "object + offset" where offset is the
1846 value stored in the pointer-to-data-member. */
1847 ptype = build_pointer_type (type);
1848 datum = fold_build_pointer_plus (fold_convert (ptype, datum), component);
1849 datum = cp_build_indirect_ref (datum, RO_NULL, complain);
1850 if (datum == error_mark_node)
1851 return error_mark_node;
1853 /* If the object expression was an rvalue, return an rvalue. */
1854 if (kind & clk_class)
1855 datum = rvalue (datum);
1856 else if (kind & clk_rvalueref)
1857 datum = move (datum);
1862 /* 5.5/6: In a .* expression whose object expression is an rvalue, the
1863 program is ill-formed if the second operand is a pointer to member
1864 function with ref-qualifier &. In a .* expression whose object
1865 expression is an lvalue, the program is ill-formed if the second
1866 operand is a pointer to member function with ref-qualifier &&. */
1867 if (FUNCTION_REF_QUALIFIED (type))
1869 bool lval = real_lvalue_p (datum);
1870 if (lval && FUNCTION_RVALUE_QUALIFIED (type))
1872 if (complain & tf_error)
1873 error ("pointer-to-member-function type %qT requires an rvalue",
1875 return error_mark_node;
1877 else if (!lval && !FUNCTION_RVALUE_QUALIFIED (type))
1879 if (complain & tf_error)
1880 error ("pointer-to-member-function type %qT requires an lvalue",
1882 return error_mark_node;
1885 return build2 (OFFSET_REF, type, datum, component);
1889 /* Return a tree node for the expression TYPENAME '(' PARMS ')'. */
1892 build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
1894 /* This is either a call to a constructor,
1895 or a C cast in C++'s `functional' notation. */
1897 /* The type to which we are casting. */
1899 vec<tree, va_gc> *parmvec;
1901 if (error_operand_p (exp) || parms == error_mark_node)
1902 return error_mark_node;
1904 if (TREE_CODE (exp) == TYPE_DECL)
1906 type = TREE_TYPE (exp);
1908 if (complain & tf_warning
1909 && TREE_DEPRECATED (type)
1910 && DECL_ARTIFICIAL (exp))
1911 warn_deprecated_use (type, NULL_TREE);
1916 /* We need to check this explicitly, since value-initialization of
1917 arrays is allowed in other situations. */
1918 if (TREE_CODE (type) == ARRAY_TYPE)
1920 if (complain & tf_error)
1921 error ("functional cast to array type %qT", type);
1922 return error_mark_node;
1925 if (type_uses_auto (type))
1927 if (complain & tf_error)
1928 error ("invalid use of %<auto%>");
1929 return error_mark_node;
1932 if (processing_template_decl)
1936 /* Diagnose this even in a template. We could also try harder
1937 to give all the usual errors when the type and args are
1939 if (TREE_CODE (type) == REFERENCE_TYPE && !parms)
1941 if (complain & tf_error)
1942 error ("invalid value-initialization of reference type");
1943 return error_mark_node;
1946 t = build_min (CAST_EXPR, type, parms);
1947 /* We don't know if it will or will not have side effects. */
1948 TREE_SIDE_EFFECTS (t) = 1;
1952 if (! MAYBE_CLASS_TYPE_P (type))
1954 if (parms == NULL_TREE)
1956 if (VOID_TYPE_P (type))
1958 return build_value_init (cv_unqualified (type), complain);
1961 /* This must build a C cast. */
1962 parms = build_x_compound_expr_from_list (parms, ELK_FUNC_CAST, complain);
1963 return cp_build_c_cast (type, parms, complain);
1966 /* Prepare to evaluate as a call to a constructor. If this expression
1967 is actually used, for example,
1969 return X (arg1, arg2, ...);
1971 then the slot being initialized will be filled in. */
1973 if (!complete_type_or_maybe_complain (type, NULL_TREE, complain))
1974 return error_mark_node;
1975 if (abstract_virtuals_error_sfinae (ACU_CAST, type, complain))
1976 return error_mark_node;
1980 If the expression list is a single-expression, the type
1981 conversion is equivalent (in definedness, and if defined in
1982 meaning) to the corresponding cast expression. */
1983 if (parms && TREE_CHAIN (parms) == NULL_TREE)
1984 return cp_build_c_cast (type, TREE_VALUE (parms), complain);
1988 The expression T(), where T is a simple-type-specifier for a
1989 non-array complete object type or the (possibly cv-qualified)
1990 void type, creates an rvalue of the specified type, which is
1991 value-initialized. */
1993 if (parms == NULL_TREE)
1995 exp = build_value_init (type, complain);
1996 exp = get_target_expr_sfinae (exp, complain);
2000 /* Call the constructor. */
2001 parmvec = make_tree_vector ();
2002 for (; parms != NULL_TREE; parms = TREE_CHAIN (parms))
2003 vec_safe_push (parmvec, TREE_VALUE (parms));
2004 exp = build_special_member_call (NULL_TREE, complete_ctor_identifier,
2005 &parmvec, type, LOOKUP_NORMAL, complain);
2006 release_tree_vector (parmvec);
2008 if (exp == error_mark_node)
2009 return error_mark_node;
2011 return build_cplus_new (type, exp, complain);
2015 /* Add new exception specifier SPEC, to the LIST we currently have.
2016 If it's already in LIST then do nothing.
2017 Moan if it's bad and we're allowed to. COMPLAIN < 0 means we
2018 know what we're doing. */
2021 add_exception_specifier (tree list, tree spec, int complain)
2026 diagnostic_t diag_type = DK_UNSPECIFIED; /* none */
2028 if (spec == error_mark_node)
2031 gcc_assert (spec && (!list || TREE_VALUE (list)));
2033 /* [except.spec] 1, type in an exception specifier shall not be
2034 incomplete, or pointer or ref to incomplete other than pointer
2036 is_ptr = TYPE_PTR_P (core);
2037 if (is_ptr || TREE_CODE (core) == REFERENCE_TYPE)
2038 core = TREE_TYPE (core);
2041 else if (VOID_TYPE_P (core))
2043 else if (TREE_CODE (core) == TEMPLATE_TYPE_PARM)
2045 else if (processing_template_decl)
2050 /* 15.4/1 says that types in an exception specifier must be complete,
2051 but it seems more reasonable to only require this on definitions
2052 and calls. So just give a pedwarn at this point; we will give an
2053 error later if we hit one of those two cases. */
2054 if (!COMPLETE_TYPE_P (complete_type (core)))
2055 diag_type = DK_PEDWARN; /* pedwarn */
2062 for (probe = list; probe; probe = TREE_CHAIN (probe))
2063 if (same_type_p (TREE_VALUE (probe), spec))
2066 list = tree_cons (NULL_TREE, spec, list);
2069 diag_type = DK_ERROR; /* error */
2071 if (diag_type != DK_UNSPECIFIED
2072 && (complain & tf_warning_or_error))
2073 cxx_incomplete_type_diagnostic (NULL_TREE, core, diag_type);
2078 /* Like nothrow_spec_p, but don't abort on deferred noexcept. */
2081 nothrow_spec_p_uninst (const_tree spec)
2083 if (DEFERRED_NOEXCEPT_SPEC_P (spec))
2085 return nothrow_spec_p (spec);
2088 /* Combine the two exceptions specifier lists LIST and ADD, and return
2092 merge_exception_specifiers (tree list, tree add)
2094 tree noex, orig_list;
2096 /* No exception-specifier or noexcept(false) are less strict than
2097 anything else. Prefer the newer variant (LIST). */
2098 if (!list || list == noexcept_false_spec)
2100 else if (!add || add == noexcept_false_spec)
2103 /* noexcept(true) and throw() are stricter than anything else.
2104 As above, prefer the more recent one (LIST). */
2105 if (nothrow_spec_p_uninst (add))
2108 /* Two implicit noexcept specs (e.g. on a destructor) are equivalent. */
2109 if (UNEVALUATED_NOEXCEPT_SPEC_P (add)
2110 && UNEVALUATED_NOEXCEPT_SPEC_P (list))
2112 /* We should have instantiated other deferred noexcept specs by now. */
2113 gcc_assert (!DEFERRED_NOEXCEPT_SPEC_P (add));
2115 if (nothrow_spec_p_uninst (list))
2117 noex = TREE_PURPOSE (list);
2118 gcc_checking_assert (!TREE_PURPOSE (add)
2119 || cp_tree_equal (noex, TREE_PURPOSE (add)));
2121 /* Combine the dynamic-exception-specifiers, if any. */
2123 for (; add && TREE_VALUE (add); add = TREE_CHAIN (add))
2125 tree spec = TREE_VALUE (add);
2128 for (probe = orig_list; probe && TREE_VALUE (probe);
2129 probe = TREE_CHAIN (probe))
2130 if (same_type_p (TREE_VALUE (probe), spec))
2134 spec = build_tree_list (NULL_TREE, spec);
2135 TREE_CHAIN (spec) = list;
2140 /* Keep the noexcept-specifier at the beginning of the list. */
2141 if (noex != TREE_PURPOSE (list))
2142 list = tree_cons (noex, TREE_VALUE (list), TREE_CHAIN (list));
2147 /* Subroutine of build_call. Ensure that each of the types in the
2148 exception specification is complete. Technically, 15.4/1 says that
2149 they need to be complete when we see a declaration of the function,
2150 but we should be able to get away with only requiring this when the
2151 function is defined or called. See also add_exception_specifier. */
2154 require_complete_eh_spec_types (tree fntype, tree decl)
2157 /* Don't complain about calls to op new. */
2158 if (decl && DECL_ARTIFICIAL (decl))
2160 for (raises = TYPE_RAISES_EXCEPTIONS (fntype); raises;
2161 raises = TREE_CHAIN (raises))
2163 tree type = TREE_VALUE (raises);
2164 if (type && !COMPLETE_TYPE_P (type))
2168 ("call to function %qD which throws incomplete type %q#T",
2171 error ("call to function which throws incomplete type %q#T",
2178 #include "gt-cp-typeck2.h"