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);
704 = cxx_maybe_build_cleanup (sub, tf_warning_or_error))
705 finish_eh_cleanup (cleanup);
714 if (!initializer_constant_valid_p (init, type))
717 tree cons = copy_node (init);
718 CONSTRUCTOR_ELTS (init) = NULL;
719 code = build2 (MODIFY_EXPR, type, dest, cons);
720 code = build_stmt (input_location, EXPR_STMT, code);
722 num_split_elts += CONSTRUCTOR_NELTS (init);
730 /* The rest of the initializer is now a constant. */
731 TREE_CONSTANT (init) = 1;
732 return complete_p && complete_ctor_at_level_p (TREE_TYPE (init),
733 num_split_elts, inner_type);
736 /* A subroutine of store_init_value. Splits non-constant static
737 initializer INIT into a constant part and generates code to
738 perform the non-constant part of the initialization to DEST.
739 Returns the code for the runtime init. */
742 split_nonconstant_init (tree dest, tree init)
746 if (TREE_CODE (init) == TARGET_EXPR)
747 init = TARGET_EXPR_INITIAL (init);
748 if (TREE_CODE (init) == CONSTRUCTOR)
750 code = push_stmt_list ();
751 if (split_nonconstant_init_1 (dest, init))
753 code = pop_stmt_list (code);
754 DECL_INITIAL (dest) = init;
755 TREE_READONLY (dest) = 0;
758 code = build2 (INIT_EXPR, TREE_TYPE (dest), dest, init);
763 /* Perform appropriate conversions on the initial value of a variable,
764 store it in the declaration DECL,
765 and print any error messages that are appropriate.
766 If the init is invalid, store an ERROR_MARK.
768 C++: Note that INIT might be a TREE_LIST, which would mean that it is
769 a base class initializer for some aggregate type, hopefully compatible
770 with DECL. If INIT is a single element, and DECL is an aggregate
771 type, we silently convert INIT into a TREE_LIST, allowing a constructor
774 If INIT is a TREE_LIST and there is no constructor, turn INIT
775 into a CONSTRUCTOR and use standard initialization techniques.
776 Perhaps a warning should be generated?
778 Returns code to be executed if initialization could not be performed
779 for static variable. In that case, caller must emit the code. */
782 store_init_value (tree decl, tree init, vec<tree, va_gc>** cleanups, int flags)
786 /* If variable's type was invalidly declared, just ignore it. */
788 type = TREE_TYPE (decl);
789 if (TREE_CODE (type) == ERROR_MARK)
792 if (MAYBE_CLASS_TYPE_P (type))
794 if (TREE_CODE (init) == TREE_LIST)
796 error ("constructor syntax used, but no constructor declared "
797 "for type %qT", type);
798 init = build_constructor_from_list (init_list_type_node, nreverse (init));
802 /* End of special C++ code. */
804 if (flags & LOOKUP_ALREADY_DIGESTED)
807 /* Digest the specified initializer into an expression. */
808 value = digest_init_flags (type, init, flags);
810 value = extend_ref_init_temps (decl, value, cleanups);
812 /* In C++11 constant expression is a semantic, not syntactic, property.
813 In C++98, make sure that what we thought was a constant expression at
814 template definition time is still constant and otherwise perform this
815 as optimization, e.g. to fold SIZEOF_EXPRs in the initializer. */
816 if (decl_maybe_constant_var_p (decl) || TREE_STATIC (decl))
819 value = instantiate_non_dependent_expr (value);
820 if (DECL_DECLARED_CONSTEXPR_P (decl)
821 || DECL_IN_AGGR_P (decl))
823 /* Diagnose a non-constant initializer for constexpr. */
824 if (processing_template_decl
825 && !require_potential_constant_expression (value))
826 value = error_mark_node;
828 value = cxx_constant_value (value, decl);
830 value = maybe_constant_init (value, decl);
831 if (TREE_CODE (value) == CONSTRUCTOR && cp_has_mutable_p (type))
832 /* Poison this CONSTRUCTOR so it can't be copied to another
833 constexpr variable. */
834 CONSTRUCTOR_MUTABLE_POISON (value) = true;
835 const_init = (reduced_constant_expression_p (value)
836 || error_operand_p (value));
837 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl) = const_init;
838 TREE_CONSTANT (decl) = const_init && decl_maybe_constant_var_p (decl);
841 if (cxx_dialect >= cxx14 && CLASS_TYPE_P (strip_array_types (type)))
842 /* Handle aggregate NSDMI in non-constant initializers, too. */
843 value = replace_placeholders (value, decl);
845 /* If the initializer is not a constant, fill in DECL_INITIAL with
846 the bits that are constant, and then return an expression that
847 will perform the dynamic initialization. */
848 if (value != error_mark_node
849 && (TREE_SIDE_EFFECTS (value)
850 || array_of_runtime_bound_p (type)
851 || ! reduced_constant_expression_p (value)))
852 return split_nonconstant_init (decl, value);
853 /* If the value is a constant, just put it in DECL_INITIAL. If DECL
854 is an automatic variable, the middle end will turn this into a
855 dynamic initialization later. */
856 DECL_INITIAL (decl) = value;
861 /* Give diagnostic about narrowing conversions within { }. */
864 check_narrowing (tree type, tree init, tsubst_flags_t complain)
866 tree ftype = unlowered_expr_type (init);
870 if (((!warn_narrowing || !(complain & tf_warning))
871 && cxx_dialect == cxx98)
872 || !ARITHMETIC_TYPE_P (type))
875 if (BRACE_ENCLOSED_INITIALIZER_P (init)
876 && TREE_CODE (type) == COMPLEX_TYPE)
878 tree elttype = TREE_TYPE (type);
879 if (CONSTRUCTOR_NELTS (init) > 0)
880 ok &= check_narrowing (elttype, CONSTRUCTOR_ELT (init, 0)->value,
882 if (CONSTRUCTOR_NELTS (init) > 1)
883 ok &= check_narrowing (elttype, CONSTRUCTOR_ELT (init, 1)->value,
888 init = fold_non_dependent_expr (init);
890 if (TREE_CODE (type) == INTEGER_TYPE
891 && TREE_CODE (ftype) == REAL_TYPE)
893 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
894 && CP_INTEGRAL_TYPE_P (type))
896 if (TREE_CODE (ftype) == ENUMERAL_TYPE)
897 /* Check for narrowing based on the values of the enumeration. */
898 ftype = ENUM_UNDERLYING_TYPE (ftype);
899 if ((tree_int_cst_lt (TYPE_MAX_VALUE (type),
900 TYPE_MAX_VALUE (ftype))
901 || tree_int_cst_lt (TYPE_MIN_VALUE (ftype),
902 TYPE_MIN_VALUE (type)))
903 && (TREE_CODE (init) != INTEGER_CST
904 || !int_fits_type_p (init, type)))
907 else if (TREE_CODE (ftype) == REAL_TYPE
908 && TREE_CODE (type) == REAL_TYPE)
910 if (TYPE_PRECISION (type) < TYPE_PRECISION (ftype))
912 if (TREE_CODE (init) == REAL_CST)
914 /* Issue 703: Loss of precision is OK as long as the value is
915 within the representable range of the new type. */
917 d = TREE_REAL_CST (init);
918 real_convert (&r, TYPE_MODE (type), &d);
926 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (ftype)
927 && TREE_CODE (type) == REAL_TYPE)
930 if (TREE_CODE (init) == INTEGER_CST)
932 d = real_value_from_int_cst (0, init);
933 if (exact_real_truncate (TYPE_MODE (type), &d))
940 if (cxx_dialect == cxx98)
941 warning_at (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
942 "narrowing conversion of %qE from %qT to %qT inside { } "
943 "is ill-formed in C++11", init, ftype, type);
944 else if (!TREE_CONSTANT (init))
946 if (complain & tf_warning_or_error)
948 pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
949 "narrowing conversion of %qE from %qT to %qT inside { }",
954 else if (complain & tf_error)
956 int savederrorcount = errorcount;
957 global_dc->pedantic_errors = 1;
958 pedwarn (EXPR_LOC_OR_LOC (init, input_location), OPT_Wnarrowing,
959 "narrowing conversion of %qE from %qT to %qT "
960 "inside { }", init, ftype, type);
961 if (errorcount == savederrorcount)
963 global_dc->pedantic_errors = flag_pedantic_errors;
967 return cxx_dialect == cxx98 || ok;
970 /* Process the initializer INIT for a variable of type TYPE, emitting
971 diagnostics for invalid initializers and converting the initializer as
974 For aggregate types, it assumes that reshape_init has already run, thus the
975 initializer will have the right shape (brace elision has been undone).
977 NESTED is true iff we are being called for an element of a CONSTRUCTOR. */
980 digest_init_r (tree type, tree init, bool nested, int flags,
981 tsubst_flags_t complain)
983 enum tree_code code = TREE_CODE (type);
985 if (error_operand_p (init))
986 return error_mark_node;
990 /* We must strip the outermost array type when completing the type,
991 because the its bounds might be incomplete at the moment. */
992 if (!complete_type_or_maybe_complain (TREE_CODE (type) == ARRAY_TYPE
993 ? TREE_TYPE (type) : type, NULL_TREE,
995 return error_mark_node;
997 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue
998 (g++.old-deja/g++.law/casts2.C). */
999 if (TREE_CODE (init) == NON_LVALUE_EXPR)
1000 init = TREE_OPERAND (init, 0);
1002 /* Initialization of an array of chars from a string constant. The initializer
1003 can be optionally enclosed in braces, but reshape_init has already removed
1004 them if they were present. */
1005 if (code == ARRAY_TYPE)
1007 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
1008 if (char_type_p (typ1)
1010 && TREE_CODE (init) == STRING_CST)
1012 tree char_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (init)));
1014 if (TYPE_PRECISION (typ1) == BITS_PER_UNIT)
1016 if (char_type != char_type_node)
1018 if (complain & tf_error)
1019 error ("char-array initialized from wide string");
1020 return error_mark_node;
1025 if (char_type == char_type_node)
1027 if (complain & tf_error)
1028 error ("int-array initialized from non-wide string");
1029 return error_mark_node;
1031 else if (char_type != typ1)
1033 if (complain & tf_error)
1034 error ("int-array initialized from incompatible "
1036 return error_mark_node;
1040 if (type != TREE_TYPE (init))
1042 init = copy_node (init);
1043 TREE_TYPE (init) = type;
1045 if (TYPE_DOMAIN (type) != 0 && TREE_CONSTANT (TYPE_SIZE (type)))
1047 int size = TREE_INT_CST_LOW (TYPE_SIZE (type));
1048 size = (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
1049 /* In C it is ok to subtract 1 from the length of the string
1050 because it's ok to ignore the terminating null char that is
1051 counted in the length of the constant, but in C++ this would
1053 if (size < TREE_STRING_LENGTH (init))
1054 permerror (input_location, "initializer-string for array "
1055 "of chars is too long");
1061 /* Handle scalar types (including conversions) and references. */
1062 if ((TREE_CODE (type) != COMPLEX_TYPE
1063 || BRACE_ENCLOSED_INITIALIZER_P (init))
1064 && (SCALAR_TYPE_P (type) || code == REFERENCE_TYPE))
1069 flags |= LOOKUP_NO_NARROWING;
1070 init = convert_for_initialization (0, type, init, flags,
1071 ICR_INIT, NULL_TREE, 0,
1075 /* Skip any conversions since we'll be outputting the underlying
1077 while (CONVERT_EXPR_P (*exp)
1078 || TREE_CODE (*exp) == NON_LVALUE_EXPR)
1079 exp = &TREE_OPERAND (*exp, 0);
1081 *exp = cplus_expand_constant (*exp);
1086 /* Come here only for aggregates: records, arrays, unions, complex numbers
1088 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
1089 || TREE_CODE (type) == VECTOR_TYPE
1090 || TREE_CODE (type) == RECORD_TYPE
1091 || TREE_CODE (type) == UNION_TYPE
1092 || TREE_CODE (type) == COMPLEX_TYPE);
1094 /* "If T is a class type and the initializer list has a single
1095 element of type cv U, where U is T or a class derived from T,
1096 the object is initialized from that element." */
1097 if (cxx_dialect >= cxx11
1098 && BRACE_ENCLOSED_INITIALIZER_P (init)
1099 && CONSTRUCTOR_NELTS (init) == 1
1100 && (CLASS_TYPE_P (type) || VECTOR_TYPE_P (type)))
1102 tree elt = CONSTRUCTOR_ELT (init, 0)->value;
1103 if (reference_related_p (type, TREE_TYPE (elt)))
1107 if (BRACE_ENCLOSED_INITIALIZER_P (init)
1108 && !TYPE_NON_AGGREGATE_CLASS (type))
1109 return process_init_constructor (type, init, complain);
1112 if (COMPOUND_LITERAL_P (init) && TREE_CODE (type) == ARRAY_TYPE)
1114 if (complain & tf_error)
1115 error ("cannot initialize aggregate of type %qT with "
1116 "a compound literal", type);
1118 return error_mark_node;
1121 if (TREE_CODE (type) == ARRAY_TYPE
1122 && !BRACE_ENCLOSED_INITIALIZER_P (init))
1124 /* Allow the result of build_array_copy and of
1125 build_value_init_noctor. */
1126 if ((TREE_CODE (init) == VEC_INIT_EXPR
1127 || TREE_CODE (init) == CONSTRUCTOR)
1128 && (same_type_ignoring_top_level_qualifiers_p
1129 (type, TREE_TYPE (init))))
1132 if (complain & tf_error)
1133 error ("array must be initialized with a brace-enclosed"
1135 return error_mark_node;
1138 return convert_for_initialization (NULL_TREE, type, init,
1140 ICR_INIT, NULL_TREE, 0,
1146 digest_init (tree type, tree init, tsubst_flags_t complain)
1148 return digest_init_r (type, init, false, LOOKUP_IMPLICIT, complain);
1152 digest_init_flags (tree type, tree init, int flags)
1154 return digest_init_r (type, init, false, flags, tf_warning_or_error);
1157 /* Process the initializer INIT for an NSDMI DECL (a FIELD_DECL). */
1159 digest_nsdmi_init (tree decl, tree init)
1161 gcc_assert (TREE_CODE (decl) == FIELD_DECL);
1163 int flags = LOOKUP_IMPLICIT;
1164 if (DIRECT_LIST_INIT_P (init))
1165 flags = LOOKUP_NORMAL;
1166 init = digest_init_flags (TREE_TYPE (decl), init, flags);
1167 if (TREE_CODE (init) == TARGET_EXPR)
1168 /* This represents the whole initialization. */
1169 TARGET_EXPR_DIRECT_INIT_P (init) = true;
1173 /* Set of flags used within process_init_constructor to describe the
1175 #define PICFLAG_ERRONEOUS 1
1176 #define PICFLAG_NOT_ALL_CONSTANT 2
1177 #define PICFLAG_NOT_ALL_SIMPLE 4
1178 #define PICFLAG_SIDE_EFFECTS 8
1180 /* Given an initializer INIT, return the flag (PICFLAG_*) which better
1184 picflag_from_initializer (tree init)
1186 if (init == error_mark_node)
1187 return PICFLAG_ERRONEOUS;
1188 else if (!TREE_CONSTANT (init))
1190 if (TREE_SIDE_EFFECTS (init))
1191 return PICFLAG_SIDE_EFFECTS;
1193 return PICFLAG_NOT_ALL_CONSTANT;
1195 else if (!initializer_constant_valid_p (init, TREE_TYPE (init)))
1196 return PICFLAG_NOT_ALL_SIMPLE;
1200 /* Adjust INIT for going into a CONSTRUCTOR. */
1203 massage_init_elt (tree type, tree init, tsubst_flags_t complain)
1205 init = digest_init_r (type, init, true, LOOKUP_IMPLICIT, complain);
1206 /* Strip a simple TARGET_EXPR when we know this is an initializer. */
1207 if (TREE_CODE (init) == TARGET_EXPR
1208 && !VOID_TYPE_P (TREE_TYPE (TARGET_EXPR_INITIAL (init))))
1209 init = TARGET_EXPR_INITIAL (init);
1210 /* When we defer constant folding within a statement, we may want to
1211 defer this folding as well. */
1212 tree t = fold_non_dependent_expr (init);
1213 t = maybe_constant_init (t);
1214 if (TREE_CONSTANT (t))
1219 /* Subroutine of process_init_constructor, which will process an initializer
1220 INIT for an array or vector of type TYPE. Returns the flags (PICFLAG_*)
1221 which describe the initializers. */
1224 process_init_constructor_array (tree type, tree init,
1225 tsubst_flags_t complain)
1227 unsigned HOST_WIDE_INT i, len = 0;
1229 bool unbounded = false;
1230 constructor_elt *ce;
1231 vec<constructor_elt, va_gc> *v = CONSTRUCTOR_ELTS (init);
1233 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
1234 || TREE_CODE (type) == VECTOR_TYPE);
1236 if (TREE_CODE (type) == ARRAY_TYPE)
1238 tree domain = TYPE_DOMAIN (type);
1239 if (domain && TREE_CONSTANT (TYPE_MAX_VALUE (domain)))
1240 len = wi::ext (wi::to_offset (TYPE_MAX_VALUE (domain))
1241 - wi::to_offset (TYPE_MIN_VALUE (domain)) + 1,
1242 TYPE_PRECISION (TREE_TYPE (domain)),
1243 TYPE_SIGN (TREE_TYPE (domain))).to_uhwi ();
1245 unbounded = true; /* Take as many as there are. */
1248 /* Vectors are like simple fixed-size arrays. */
1249 len = TYPE_VECTOR_SUBPARTS (type);
1251 /* There must not be more initializers than needed. */
1252 if (!unbounded && vec_safe_length (v) > len)
1254 if (complain & tf_error)
1255 error ("too many initializers for %qT", type);
1257 return PICFLAG_ERRONEOUS;
1260 FOR_EACH_VEC_SAFE_ELT (v, i, ce)
1264 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST);
1265 if (compare_tree_int (ce->index, i) != 0)
1267 ce->value = error_mark_node;
1268 sorry ("non-trivial designated initializers not supported");
1272 ce->index = size_int (i);
1273 gcc_assert (ce->value);
1274 ce->value = massage_init_elt (TREE_TYPE (type), ce->value, complain);
1276 if (ce->value != error_mark_node)
1277 gcc_assert (same_type_ignoring_top_level_qualifiers_p
1278 (TREE_TYPE (type), TREE_TYPE (ce->value)));
1280 flags |= picflag_from_initializer (ce->value);
1283 /* No more initializers. If the array is unbounded, we are done. Otherwise,
1284 we must add initializers ourselves. */
1286 for (; i < len; ++i)
1290 if (type_build_ctor_call (TREE_TYPE (type)))
1292 /* If this type needs constructors run for default-initialization,
1293 we can't rely on the back end to do it for us, so make the
1294 initialization explicit by list-initializing from T{}. */
1295 next = build_constructor (init_list_type_node, NULL);
1296 CONSTRUCTOR_IS_DIRECT_INIT (next) = true;
1297 next = massage_init_elt (TREE_TYPE (type), next, complain);
1298 if (initializer_zerop (next))
1299 /* The default zero-initialization is fine for us; don't
1300 add anything to the CONSTRUCTOR. */
1303 else if (!zero_init_p (TREE_TYPE (type)))
1304 next = build_zero_init (TREE_TYPE (type),
1305 /*nelts=*/NULL_TREE,
1306 /*static_storage_p=*/false);
1308 /* The default zero-initialization is fine for us; don't
1309 add anything to the CONSTRUCTOR. */
1314 flags |= picflag_from_initializer (next);
1315 CONSTRUCTOR_APPEND_ELT (v, size_int (i), next);
1319 CONSTRUCTOR_ELTS (init) = v;
1323 /* Subroutine of process_init_constructor, which will process an initializer
1324 INIT for a class of type TYPE. Returns the flags (PICFLAG_*) which describe
1325 the initializers. */
1328 process_init_constructor_record (tree type, tree init,
1329 tsubst_flags_t complain)
1331 vec<constructor_elt, va_gc> *v = NULL;
1335 gcc_assert (TREE_CODE (type) == RECORD_TYPE);
1336 gcc_assert (!CLASSTYPE_VBASECLASSES (type));
1337 gcc_assert (!TYPE_BINFO (type)
1338 || !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)));
1339 gcc_assert (!TYPE_POLYMORPHIC_P (type));
1343 unsigned HOST_WIDE_INT idx = 0;
1344 /* Generally, we will always have an index for each initializer (which is
1345 a FIELD_DECL, put by reshape_init), but compound literals don't go trough
1346 reshape_init. So we need to handle both cases. */
1347 for (field = TYPE_FIELDS (type); field; field = DECL_CHAIN (field))
1352 if (!DECL_NAME (field) && DECL_C_BIT_FIELD (field))
1355 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
1358 /* If this is a bitfield, first convert to the declared type. */
1359 type = TREE_TYPE (field);
1360 if (DECL_BIT_FIELD_TYPE (field))
1361 type = DECL_BIT_FIELD_TYPE (field);
1362 if (type == error_mark_node)
1363 return PICFLAG_ERRONEOUS;
1365 if (idx < vec_safe_length (CONSTRUCTOR_ELTS (init)))
1367 constructor_elt *ce = &(*CONSTRUCTOR_ELTS (init))[idx];
1370 /* We can have either a FIELD_DECL or an IDENTIFIER_NODE. The
1371 latter case can happen in templates where lookup has to be
1373 gcc_assert (TREE_CODE (ce->index) == FIELD_DECL
1374 || identifier_p (ce->index));
1375 if (ce->index != field
1376 && ce->index != DECL_NAME (field))
1378 ce->value = error_mark_node;
1379 sorry ("non-trivial designated initializers not supported");
1383 gcc_assert (ce->value);
1384 next = massage_init_elt (type, ce->value, complain);
1387 else if (DECL_INITIAL (field))
1391 /* We're using an NSDMI past a field with implicit
1392 zero-init. Go back and make it explicit. */
1394 vec_safe_truncate (v, 0);
1397 /* C++14 aggregate NSDMI. */
1398 next = get_nsdmi (field, /*ctor*/false);
1400 else if (type_build_ctor_call (TREE_TYPE (field)))
1402 /* If this type needs constructors run for
1403 default-initialization, we can't rely on the back end to do it
1404 for us, so build up TARGET_EXPRs. If the type in question is
1405 a class, just build one up; if it's an array, recurse. */
1406 next = build_constructor (init_list_type_node, NULL);
1407 /* Call this direct-initialization pending DR 1518 resolution so
1408 that explicit default ctors don't break valid C++03 code. */
1409 CONSTRUCTOR_IS_DIRECT_INIT (next) = true;
1410 next = massage_init_elt (TREE_TYPE (field), next, complain);
1412 /* Warn when some struct elements are implicitly initialized. */
1413 if ((complain & tf_warning)
1414 && !EMPTY_CONSTRUCTOR_P (init))
1415 warning (OPT_Wmissing_field_initializers,
1416 "missing initializer for member %qD", field);
1420 if (TREE_CODE (TREE_TYPE (field)) == REFERENCE_TYPE)
1422 if (complain & tf_error)
1423 error ("member %qD is uninitialized reference", field);
1425 return PICFLAG_ERRONEOUS;
1427 else if (CLASSTYPE_REF_FIELDS_NEED_INIT (TREE_TYPE (field)))
1429 if (complain & tf_error)
1430 error ("member %qD with uninitialized reference fields", field);
1432 return PICFLAG_ERRONEOUS;
1435 /* Warn when some struct elements are implicitly initialized
1437 if ((complain & tf_warning)
1438 && !EMPTY_CONSTRUCTOR_P (init))
1439 warning (OPT_Wmissing_field_initializers,
1440 "missing initializer for member %qD", field);
1442 if (!zero_init_p (TREE_TYPE (field))
1444 next = build_zero_init (TREE_TYPE (field), /*nelts=*/NULL_TREE,
1445 /*static_storage_p=*/false);
1448 /* The default zero-initialization is fine for us; don't
1449 add anything to the CONSTRUCTOR. */
1455 /* If this is a bitfield, now convert to the lowered type. */
1456 if (type != TREE_TYPE (field))
1457 next = cp_convert_and_check (TREE_TYPE (field), next, complain);
1458 flags |= picflag_from_initializer (next);
1459 CONSTRUCTOR_APPEND_ELT (v, field, next);
1462 if (idx < vec_safe_length (CONSTRUCTOR_ELTS (init)))
1464 if (complain & tf_error)
1465 error ("too many initializers for %qT", type);
1467 return PICFLAG_ERRONEOUS;
1470 CONSTRUCTOR_ELTS (init) = v;
1474 /* Subroutine of process_init_constructor, which will process a single
1475 initializer INIT for a union of type TYPE. Returns the flags (PICFLAG_*)
1476 which describe the initializer. */
1479 process_init_constructor_union (tree type, tree init,
1480 tsubst_flags_t complain)
1482 constructor_elt *ce;
1485 /* If the initializer was empty, use the union's NSDMI if it has one.
1486 Otherwise use default zero initialization. */
1487 if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
1489 for (tree field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1491 if (DECL_INITIAL (field))
1493 CONSTRUCTOR_APPEND_ELT (CONSTRUCTOR_ELTS (init),
1495 get_nsdmi (field, /*in_ctor=*/false));
1500 if (vec_safe_is_empty (CONSTRUCTOR_ELTS (init)))
1504 len = CONSTRUCTOR_ELTS (init)->length ();
1507 if (!(complain & tf_error))
1508 return PICFLAG_ERRONEOUS;
1509 error ("too many initializers for %qT", type);
1510 CONSTRUCTOR_ELTS (init)->block_remove (1, len-1);
1513 ce = &(*CONSTRUCTOR_ELTS (init))[0];
1515 /* If this element specifies a field, initialize via that field. */
1518 if (TREE_CODE (ce->index) == FIELD_DECL)
1520 else if (identifier_p (ce->index))
1522 /* This can happen within a cast, see g++.dg/opt/cse2.C. */
1523 tree name = ce->index;
1525 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1526 if (DECL_NAME (field) == name)
1530 if (complain & tf_error)
1531 error ("no field %qD found in union being initialized",
1533 ce->value = error_mark_node;
1539 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST
1540 || TREE_CODE (ce->index) == RANGE_EXPR);
1541 if (complain & tf_error)
1542 error ("index value instead of field name in union initializer");
1543 ce->value = error_mark_node;
1548 /* Find the first named field. ANSI decided in September 1990
1549 that only named fields count here. */
1550 tree field = TYPE_FIELDS (type);
1551 while (field && (!DECL_NAME (field) || TREE_CODE (field) != FIELD_DECL))
1552 field = TREE_CHAIN (field);
1553 if (field == NULL_TREE)
1555 if (complain & tf_error)
1556 error ("too many initializers for %qT", type);
1557 ce->value = error_mark_node;
1562 if (ce->value && ce->value != error_mark_node)
1563 ce->value = massage_init_elt (TREE_TYPE (ce->index), ce->value, complain);
1565 return picflag_from_initializer (ce->value);
1568 /* Process INIT, a constructor for a variable of aggregate type TYPE. The
1569 constructor is a brace-enclosed initializer, and will be modified in-place.
1571 Each element is converted to the right type through digest_init, and
1572 missing initializers are added following the language rules (zero-padding,
1575 After the execution, the initializer will have TREE_CONSTANT if all elts are
1576 constant, and TREE_STATIC set if, in addition, all elts are simple enough
1577 constants that the assembler and linker can compute them.
1579 The function returns the initializer itself, or error_mark_node in case
1583 process_init_constructor (tree type, tree init, tsubst_flags_t complain)
1587 gcc_assert (BRACE_ENCLOSED_INITIALIZER_P (init));
1589 if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1590 flags = process_init_constructor_array (type, init, complain);
1591 else if (TREE_CODE (type) == RECORD_TYPE)
1592 flags = process_init_constructor_record (type, init, complain);
1593 else if (TREE_CODE (type) == UNION_TYPE)
1594 flags = process_init_constructor_union (type, init, complain);
1598 if (flags & PICFLAG_ERRONEOUS)
1599 return error_mark_node;
1601 TREE_TYPE (init) = type;
1602 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == NULL_TREE)
1603 cp_complete_array_type (&TREE_TYPE (init), init, /*do_default=*/0);
1604 if (flags & PICFLAG_SIDE_EFFECTS)
1606 TREE_CONSTANT (init) = false;
1607 TREE_SIDE_EFFECTS (init) = true;
1609 else if (flags & PICFLAG_NOT_ALL_CONSTANT)
1610 /* Make sure TREE_CONSTANT isn't set from build_constructor. */
1611 TREE_CONSTANT (init) = false;
1614 TREE_CONSTANT (init) = 1;
1615 if (!(flags & PICFLAG_NOT_ALL_SIMPLE))
1616 TREE_STATIC (init) = 1;
1621 /* Given a structure or union value DATUM, construct and return
1622 the structure or union component which results from narrowing
1623 that value to the base specified in BASETYPE. For example, given the
1626 class L { int ii; };
1627 class A : L { ... };
1628 class B : L { ... };
1629 class C : A, B { ... };
1637 x.A::ii refers to the ii member of the L part of
1638 the A part of the C object named by X. In this case,
1639 DATUM would be x, and BASETYPE would be A.
1641 I used to think that this was nonconformant, that the standard specified
1642 that first we look up ii in A, then convert x to an L& and pull out the
1643 ii part. But in fact, it does say that we convert x to an A&; A here
1644 is known as the "naming class". (jason 2000-12-19)
1646 BINFO_P points to a variable initialized either to NULL_TREE or to the
1647 binfo for the specific base subobject we want to convert to. */
1650 build_scoped_ref (tree datum, tree basetype, tree* binfo_p)
1654 if (datum == error_mark_node)
1655 return error_mark_node;
1659 binfo = lookup_base (TREE_TYPE (datum), basetype, ba_check,
1660 NULL, tf_warning_or_error);
1662 if (!binfo || binfo == error_mark_node)
1664 *binfo_p = NULL_TREE;
1666 error_not_base_type (basetype, TREE_TYPE (datum));
1667 return error_mark_node;
1671 return build_base_path (PLUS_EXPR, datum, binfo, 1,
1672 tf_warning_or_error);
1675 /* Build a reference to an object specified by the C++ `->' operator.
1676 Usually this just involves dereferencing the object, but if the
1677 `->' operator is overloaded, then such overloads must be
1678 performed until an object which does not have the `->' operator
1679 overloaded is found. An error is reported when circular pointer
1680 delegation is detected. */
1683 build_x_arrow (location_t loc, tree expr, tsubst_flags_t complain)
1685 tree orig_expr = expr;
1686 tree type = TREE_TYPE (expr);
1687 tree last_rval = NULL_TREE;
1688 vec<tree, va_gc> *types_memoized = NULL;
1690 if (type == error_mark_node)
1691 return error_mark_node;
1693 if (processing_template_decl)
1695 if (type_dependent_expression_p (expr))
1696 return build_min_nt_loc (loc, ARROW_EXPR, expr);
1697 expr = build_non_dependent_expr (expr);
1700 if (MAYBE_CLASS_TYPE_P (type))
1702 struct tinst_level *actual_inst = current_instantiation ();
1705 while ((expr = build_new_op (loc, COMPONENT_REF,
1706 LOOKUP_NORMAL, expr, NULL_TREE, NULL_TREE,
1709 if (expr == error_mark_node)
1710 return error_mark_node;
1712 /* This provides a better instantiation backtrace in case of
1714 if (fn && DECL_USE_TEMPLATE (fn))
1715 push_tinst_level_loc (fn,
1716 (current_instantiation () != actual_inst)
1717 ? DECL_SOURCE_LOCATION (fn)
1721 if (vec_member (TREE_TYPE (expr), types_memoized))
1723 if (complain & tf_error)
1724 error ("circular pointer delegation detected");
1725 return error_mark_node;
1728 vec_safe_push (types_memoized, TREE_TYPE (expr));
1732 while (current_instantiation () != actual_inst)
1735 if (last_rval == NULL_TREE)
1737 if (complain & tf_error)
1738 error ("base operand of %<->%> has non-pointer type %qT", type);
1739 return error_mark_node;
1742 if (TREE_CODE (TREE_TYPE (last_rval)) == REFERENCE_TYPE)
1743 last_rval = convert_from_reference (last_rval);
1746 last_rval = decay_conversion (expr, complain);
1748 if (TYPE_PTR_P (TREE_TYPE (last_rval)))
1750 if (processing_template_decl)
1752 expr = build_min (ARROW_EXPR, TREE_TYPE (TREE_TYPE (last_rval)),
1754 TREE_SIDE_EFFECTS (expr) = TREE_SIDE_EFFECTS (last_rval);
1758 return cp_build_indirect_ref (last_rval, RO_NULL, complain);
1761 if (complain & tf_error)
1764 error ("result of %<operator->()%> yields non-pointer result");
1766 error ("base operand of %<->%> is not a pointer");
1768 return error_mark_node;
1771 /* Return an expression for "DATUM .* COMPONENT". DATUM has not
1772 already been checked out to be of aggregate type. */
1775 build_m_component_ref (tree datum, tree component, tsubst_flags_t complain)
1783 if (error_operand_p (datum) || error_operand_p (component))
1784 return error_mark_node;
1786 datum = mark_lvalue_use (datum);
1787 component = mark_rvalue_use (component);
1789 ptrmem_type = TREE_TYPE (component);
1790 if (!TYPE_PTRMEM_P (ptrmem_type))
1792 if (complain & tf_error)
1793 error ("%qE cannot be used as a member pointer, since it is of "
1794 "type %qT", component, ptrmem_type);
1795 return error_mark_node;
1798 objtype = TYPE_MAIN_VARIANT (TREE_TYPE (datum));
1799 if (! MAYBE_CLASS_TYPE_P (objtype))
1801 if (complain & tf_error)
1802 error ("cannot apply member pointer %qE to %qE, which is of "
1803 "non-class type %qT", component, datum, objtype);
1804 return error_mark_node;
1807 type = TYPE_PTRMEM_POINTED_TO_TYPE (ptrmem_type);
1808 ctype = complete_type (TYPE_PTRMEM_CLASS_TYPE (ptrmem_type));
1810 if (!COMPLETE_TYPE_P (ctype))
1812 if (!same_type_p (ctype, objtype))
1818 binfo = lookup_base (objtype, ctype, ba_check, NULL, complain);
1823 if (complain & tf_error)
1824 error ("pointer to member type %qT incompatible with object "
1825 "type %qT", type, objtype);
1826 return error_mark_node;
1828 else if (binfo == error_mark_node)
1829 return error_mark_node;
1832 if (TYPE_PTRDATAMEM_P (ptrmem_type))
1834 cp_lvalue_kind kind = lvalue_kind (datum);
1837 /* Compute the type of the field, as described in [expr.ref].
1838 There's no such thing as a mutable pointer-to-member, so
1839 things are not as complex as they are for references to
1840 non-static data members. */
1841 type = cp_build_qualified_type (type,
1842 (cp_type_quals (type)
1843 | cp_type_quals (TREE_TYPE (datum))));
1845 datum = build_address (datum);
1847 /* Convert object to the correct base. */
1850 datum = build_base_path (PLUS_EXPR, datum, binfo, 1, complain);
1851 if (datum == error_mark_node)
1852 return error_mark_node;
1855 /* Build an expression for "object + offset" where offset is the
1856 value stored in the pointer-to-data-member. */
1857 ptype = build_pointer_type (type);
1858 datum = fold_build_pointer_plus (fold_convert (ptype, datum), component);
1859 datum = cp_build_indirect_ref (datum, RO_NULL, complain);
1860 if (datum == error_mark_node)
1861 return error_mark_node;
1863 /* If the object expression was an rvalue, return an rvalue. */
1864 if (kind & clk_class)
1865 datum = rvalue (datum);
1866 else if (kind & clk_rvalueref)
1867 datum = move (datum);
1872 /* 5.5/6: In a .* expression whose object expression is an rvalue, the
1873 program is ill-formed if the second operand is a pointer to member
1874 function with ref-qualifier &. In a .* expression whose object
1875 expression is an lvalue, the program is ill-formed if the second
1876 operand is a pointer to member function with ref-qualifier &&. */
1877 if (FUNCTION_REF_QUALIFIED (type))
1879 bool lval = real_lvalue_p (datum);
1880 if (lval && FUNCTION_RVALUE_QUALIFIED (type))
1882 if (complain & tf_error)
1883 error ("pointer-to-member-function type %qT requires an rvalue",
1885 return error_mark_node;
1887 else if (!lval && !FUNCTION_RVALUE_QUALIFIED (type))
1889 if (complain & tf_error)
1890 error ("pointer-to-member-function type %qT requires an lvalue",
1892 return error_mark_node;
1895 return build2 (OFFSET_REF, type, datum, component);
1899 /* Return a tree node for the expression TYPENAME '(' PARMS ')'. */
1902 build_functional_cast (tree exp, tree parms, tsubst_flags_t complain)
1904 /* This is either a call to a constructor,
1905 or a C cast in C++'s `functional' notation. */
1907 /* The type to which we are casting. */
1909 vec<tree, va_gc> *parmvec;
1911 if (error_operand_p (exp) || parms == error_mark_node)
1912 return error_mark_node;
1914 if (TREE_CODE (exp) == TYPE_DECL)
1916 type = TREE_TYPE (exp);
1918 if (complain & tf_warning
1919 && TREE_DEPRECATED (type)
1920 && DECL_ARTIFICIAL (exp))
1921 warn_deprecated_use (type, NULL_TREE);
1926 /* We need to check this explicitly, since value-initialization of
1927 arrays is allowed in other situations. */
1928 if (TREE_CODE (type) == ARRAY_TYPE)
1930 if (complain & tf_error)
1931 error ("functional cast to array type %qT", type);
1932 return error_mark_node;
1935 if (type_uses_auto (type))
1937 if (complain & tf_error)
1938 error ("invalid use of %<auto%>");
1939 return error_mark_node;
1942 if (processing_template_decl)
1946 /* Diagnose this even in a template. We could also try harder
1947 to give all the usual errors when the type and args are
1949 if (TREE_CODE (type) == REFERENCE_TYPE && !parms)
1951 if (complain & tf_error)
1952 error ("invalid value-initialization of reference type");
1953 return error_mark_node;
1956 t = build_min (CAST_EXPR, type, parms);
1957 /* We don't know if it will or will not have side effects. */
1958 TREE_SIDE_EFFECTS (t) = 1;
1962 if (! MAYBE_CLASS_TYPE_P (type))
1964 if (parms == NULL_TREE)
1966 if (VOID_TYPE_P (type))
1968 return build_value_init (cv_unqualified (type), complain);
1971 /* This must build a C cast. */
1972 parms = build_x_compound_expr_from_list (parms, ELK_FUNC_CAST, complain);
1973 return cp_build_c_cast (type, parms, complain);
1976 /* Prepare to evaluate as a call to a constructor. If this expression
1977 is actually used, for example,
1979 return X (arg1, arg2, ...);
1981 then the slot being initialized will be filled in. */
1983 if (!complete_type_or_maybe_complain (type, NULL_TREE, complain))
1984 return error_mark_node;
1985 if (abstract_virtuals_error_sfinae (ACU_CAST, type, complain))
1986 return error_mark_node;
1990 If the expression list is a single-expression, the type
1991 conversion is equivalent (in definedness, and if defined in
1992 meaning) to the corresponding cast expression. */
1993 if (parms && TREE_CHAIN (parms) == NULL_TREE)
1994 return cp_build_c_cast (type, TREE_VALUE (parms), complain);
1998 The expression T(), where T is a simple-type-specifier for a
1999 non-array complete object type or the (possibly cv-qualified)
2000 void type, creates an rvalue of the specified type, which is
2001 value-initialized. */
2003 if (parms == NULL_TREE)
2005 exp = build_value_init (type, complain);
2006 exp = get_target_expr_sfinae (exp, complain);
2010 /* Call the constructor. */
2011 parmvec = make_tree_vector ();
2012 for (; parms != NULL_TREE; parms = TREE_CHAIN (parms))
2013 vec_safe_push (parmvec, TREE_VALUE (parms));
2014 exp = build_special_member_call (NULL_TREE, complete_ctor_identifier,
2015 &parmvec, type, LOOKUP_NORMAL, complain);
2016 release_tree_vector (parmvec);
2018 if (exp == error_mark_node)
2019 return error_mark_node;
2021 return build_cplus_new (type, exp, complain);
2025 /* Add new exception specifier SPEC, to the LIST we currently have.
2026 If it's already in LIST then do nothing.
2027 Moan if it's bad and we're allowed to. COMPLAIN < 0 means we
2028 know what we're doing. */
2031 add_exception_specifier (tree list, tree spec, int complain)
2036 diagnostic_t diag_type = DK_UNSPECIFIED; /* none */
2038 if (spec == error_mark_node)
2041 gcc_assert (spec && (!list || TREE_VALUE (list)));
2043 /* [except.spec] 1, type in an exception specifier shall not be
2044 incomplete, or pointer or ref to incomplete other than pointer
2046 is_ptr = TYPE_PTR_P (core);
2047 if (is_ptr || TREE_CODE (core) == REFERENCE_TYPE)
2048 core = TREE_TYPE (core);
2051 else if (VOID_TYPE_P (core))
2053 else if (TREE_CODE (core) == TEMPLATE_TYPE_PARM)
2055 else if (processing_template_decl)
2060 /* 15.4/1 says that types in an exception specifier must be complete,
2061 but it seems more reasonable to only require this on definitions
2062 and calls. So just give a pedwarn at this point; we will give an
2063 error later if we hit one of those two cases. */
2064 if (!COMPLETE_TYPE_P (complete_type (core)))
2065 diag_type = DK_PEDWARN; /* pedwarn */
2072 for (probe = list; probe; probe = TREE_CHAIN (probe))
2073 if (same_type_p (TREE_VALUE (probe), spec))
2076 list = tree_cons (NULL_TREE, spec, list);
2079 diag_type = DK_ERROR; /* error */
2081 if (diag_type != DK_UNSPECIFIED
2082 && (complain & tf_warning_or_error))
2083 cxx_incomplete_type_diagnostic (NULL_TREE, core, diag_type);
2088 /* Like nothrow_spec_p, but don't abort on deferred noexcept. */
2091 nothrow_spec_p_uninst (const_tree spec)
2093 if (DEFERRED_NOEXCEPT_SPEC_P (spec))
2095 return nothrow_spec_p (spec);
2098 /* Combine the two exceptions specifier lists LIST and ADD, and return
2102 merge_exception_specifiers (tree list, tree add)
2104 tree noex, orig_list;
2106 /* No exception-specifier or noexcept(false) are less strict than
2107 anything else. Prefer the newer variant (LIST). */
2108 if (!list || list == noexcept_false_spec)
2110 else if (!add || add == noexcept_false_spec)
2113 /* noexcept(true) and throw() are stricter than anything else.
2114 As above, prefer the more recent one (LIST). */
2115 if (nothrow_spec_p_uninst (add))
2118 /* Two implicit noexcept specs (e.g. on a destructor) are equivalent. */
2119 if (UNEVALUATED_NOEXCEPT_SPEC_P (add)
2120 && UNEVALUATED_NOEXCEPT_SPEC_P (list))
2122 /* We should have instantiated other deferred noexcept specs by now. */
2123 gcc_assert (!DEFERRED_NOEXCEPT_SPEC_P (add));
2125 if (nothrow_spec_p_uninst (list))
2127 noex = TREE_PURPOSE (list);
2128 gcc_checking_assert (!TREE_PURPOSE (add)
2129 || cp_tree_equal (noex, TREE_PURPOSE (add)));
2131 /* Combine the dynamic-exception-specifiers, if any. */
2133 for (; add && TREE_VALUE (add); add = TREE_CHAIN (add))
2135 tree spec = TREE_VALUE (add);
2138 for (probe = orig_list; probe && TREE_VALUE (probe);
2139 probe = TREE_CHAIN (probe))
2140 if (same_type_p (TREE_VALUE (probe), spec))
2144 spec = build_tree_list (NULL_TREE, spec);
2145 TREE_CHAIN (spec) = list;
2150 /* Keep the noexcept-specifier at the beginning of the list. */
2151 if (noex != TREE_PURPOSE (list))
2152 list = tree_cons (noex, TREE_VALUE (list), TREE_CHAIN (list));
2157 /* Subroutine of build_call. Ensure that each of the types in the
2158 exception specification is complete. Technically, 15.4/1 says that
2159 they need to be complete when we see a declaration of the function,
2160 but we should be able to get away with only requiring this when the
2161 function is defined or called. See also add_exception_specifier. */
2164 require_complete_eh_spec_types (tree fntype, tree decl)
2167 /* Don't complain about calls to op new. */
2168 if (decl && DECL_ARTIFICIAL (decl))
2170 for (raises = TYPE_RAISES_EXCEPTIONS (fntype); raises;
2171 raises = TREE_CHAIN (raises))
2173 tree type = TREE_VALUE (raises);
2174 if (type && !COMPLETE_TYPE_P (type))
2178 ("call to function %qD which throws incomplete type %q#T",
2181 error ("call to function which throws incomplete type %q#T",
2188 #include "gt-cp-typeck2.h"