1 /* Report error messages, build initializers, and perform
2 some front-end optimizations for C++ compiler.
3 Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2001, 2002, 2004, 2005, 2006
5 Free Software Foundation, Inc.
6 Hacked by Michael Tiemann (tiemann@cygnus.com)
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 2, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING. If not, write to
22 the Free Software Foundation, 51 Franklin Street, Fifth Floor,
23 Boston, MA 02110-1301, USA. */
26 /* This file is part of the C++ front end.
27 It contains routines to build C++ expressions given their operands,
28 including computing the types of the result, C and C++ specific error
29 checks, and some optimization. */
33 #include "coretypes.h"
40 #include "diagnostic.h"
43 process_init_constructor (tree type, tree init);
46 /* Print an error message stemming from an attempt to use
47 BASETYPE as a base class for TYPE. */
50 error_not_base_type (tree basetype, tree type)
52 if (TREE_CODE (basetype) == FUNCTION_DECL)
53 basetype = DECL_CONTEXT (basetype);
54 error ("type %qT is not a base type for type %qT", basetype, type);
55 return error_mark_node;
59 binfo_or_else (tree base, tree type)
61 tree binfo = lookup_base (type, base, ba_unique, NULL);
63 if (binfo == error_mark_node)
66 error_not_base_type (base, type);
70 /* According to ARM $7.1.6, "A `const' object may be initialized, but its
71 value may not be changed thereafter. Thus, we emit hard errors for these,
72 rather than just pedwarns. If `SOFT' is 1, then we just pedwarn. (For
73 example, conversions to references.) */
76 readonly_error (tree arg, const char* string, int soft)
79 void (*fn) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
86 if (TREE_CODE (arg) == COMPONENT_REF)
88 if (TYPE_READONLY (TREE_TYPE (TREE_OPERAND (arg, 0))))
89 fmt = "%s of data-member %qD in read-only structure";
91 fmt = "%s of read-only data-member %qD";
92 (*fn) (fmt, string, TREE_OPERAND (arg, 1));
94 else if (TREE_CODE (arg) == VAR_DECL)
96 if (DECL_LANG_SPECIFIC (arg)
97 && DECL_IN_AGGR_P (arg)
98 && !TREE_STATIC (arg))
99 fmt = "%s of constant field %qD";
101 fmt = "%s of read-only variable %qD";
102 (*fn) (fmt, string, arg);
104 else if (TREE_CODE (arg) == PARM_DECL)
105 (*fn) ("%s of read-only parameter %qD", string, arg);
106 else if (TREE_CODE (arg) == INDIRECT_REF
107 && TREE_CODE (TREE_TYPE (TREE_OPERAND (arg, 0))) == REFERENCE_TYPE
108 && (TREE_CODE (TREE_OPERAND (arg, 0)) == VAR_DECL
109 || TREE_CODE (TREE_OPERAND (arg, 0)) == PARM_DECL))
110 (*fn) ("%s of read-only reference %qD", string, TREE_OPERAND (arg, 0));
111 else if (TREE_CODE (arg) == RESULT_DECL)
112 (*fn) ("%s of read-only named return value %qD", string, arg);
113 else if (TREE_CODE (arg) == FUNCTION_DECL)
114 (*fn) ("%s of function %qD", string, arg);
116 (*fn) ("%s of read-only location", string);
120 /* Structure that holds information about declarations whose type was
121 incomplete and we could not check whether it was abstract or not. */
123 struct pending_abstract_type GTY((chain_next ("%h.next")))
125 /* Declaration which we are checking for abstractness. It is either
126 a DECL node, or an IDENTIFIER_NODE if we do not have a full
127 declaration available. */
130 /* Type which will be checked for abstractness. */
133 /* Position of the declaration. This is only needed for IDENTIFIER_NODEs,
134 because DECLs already carry locus information. */
137 /* Link to the next element in list. */
138 struct pending_abstract_type* next;
142 /* Compute the hash value of the node VAL. This function is used by the
143 hash table abstract_pending_vars. */
146 pat_calc_hash (const void* val)
148 const struct pending_abstract_type *pat =
149 (const struct pending_abstract_type *) val;
150 return (hashval_t) TYPE_UID (pat->type);
154 /* Compare node VAL1 with the type VAL2. This function is used by the
155 hash table abstract_pending_vars. */
158 pat_compare (const void* val1, const void* val2)
160 const struct pending_abstract_type *pat1 =
161 (const struct pending_abstract_type *) val1;
162 tree type2 = (tree)val2;
164 return (pat1->type == type2);
167 /* Hash table that maintains pending_abstract_type nodes, for which we still
168 need to check for type abstractness. The key of the table is the type
169 of the declaration. */
170 static GTY ((param_is (struct pending_abstract_type)))
171 htab_t abstract_pending_vars = NULL;
174 /* This function is called after TYPE is completed, and will check if there
175 are pending declarations for which we still need to verify the abstractness
176 of TYPE, and emit a diagnostic (through abstract_virtuals_error) if TYPE
177 turned out to be incomplete. */
180 complete_type_check_abstract (tree type)
183 struct pending_abstract_type *pat;
184 location_t cur_loc = input_location;
186 gcc_assert (COMPLETE_TYPE_P (type));
188 if (!abstract_pending_vars)
191 /* Retrieve the list of pending declarations for this type. */
192 slot = htab_find_slot_with_hash (abstract_pending_vars, type,
193 (hashval_t)TYPE_UID (type), NO_INSERT);
196 pat = (struct pending_abstract_type*)*slot;
199 /* If the type is not abstract, do not do anything. */
200 if (CLASSTYPE_PURE_VIRTUALS (type))
202 struct pending_abstract_type *prev = 0, *next;
204 /* Reverse the list to emit the errors in top-down order. */
205 for (; pat; pat = next)
213 /* Go through the list, and call abstract_virtuals_error for each
214 element: it will issue a diagnostic if the type is abstract. */
217 gcc_assert (type == pat->type);
219 /* Tweak input_location so that the diagnostic appears at the correct
220 location. Notice that this is only needed if the decl is an
222 input_location = pat->locus;
223 abstract_virtuals_error (pat->decl, pat->type);
228 htab_clear_slot (abstract_pending_vars, slot);
230 input_location = cur_loc;
234 /* If TYPE has abstract virtual functions, issue an error about trying
235 to create an object of that type. DECL is the object declared, or
236 NULL_TREE if the declaration is unavailable. Returns 1 if an error
237 occurred; zero if all was well. */
240 abstract_virtuals_error (tree decl, tree type)
244 /* This function applies only to classes. Any other entity can never
246 if (!CLASS_TYPE_P (type))
249 /* If the type is incomplete, we register it within a hash table,
250 so that we can check again once it is completed. This makes sense
251 only for objects for which we have a declaration or at least a
253 if (!COMPLETE_TYPE_P (type))
256 struct pending_abstract_type *pat;
258 gcc_assert (!decl || DECL_P (decl)
259 || TREE_CODE (decl) == IDENTIFIER_NODE);
261 if (!abstract_pending_vars)
262 abstract_pending_vars = htab_create_ggc (31, &pat_calc_hash,
265 slot = htab_find_slot_with_hash (abstract_pending_vars, type,
266 (hashval_t)TYPE_UID (type), INSERT);
268 pat = GGC_NEW (struct pending_abstract_type);
271 pat->locus = ((decl && DECL_P (decl))
272 ? DECL_SOURCE_LOCATION (decl)
275 pat->next = (struct pending_abstract_type *) *slot;
281 if (!TYPE_SIZE (type))
282 /* TYPE is being defined, and during that time
283 CLASSTYPE_PURE_VIRTUALS holds the inline friends. */
286 pure = CLASSTYPE_PURE_VIRTUALS (type);
292 if (TREE_CODE (decl) == RESULT_DECL)
295 if (TREE_CODE (decl) == VAR_DECL)
296 error ("cannot declare variable %q+D to be of abstract "
297 "type %qT", decl, type);
298 else if (TREE_CODE (decl) == PARM_DECL)
299 error ("cannot declare parameter %q+D to be of abstract type %qT",
301 else if (TREE_CODE (decl) == FIELD_DECL)
302 error ("cannot declare field %q+D to be of abstract type %qT",
304 else if (TREE_CODE (decl) == FUNCTION_DECL
305 && TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE)
306 error ("invalid abstract return type for member function %q+#D", decl);
307 else if (TREE_CODE (decl) == FUNCTION_DECL)
308 error ("invalid abstract return type for function %q+#D", decl);
309 else if (TREE_CODE (decl) == IDENTIFIER_NODE)
310 /* Here we do not have location information. */
311 error ("invalid abstract type %qT for %qE", type, decl);
313 error ("invalid abstract type for %q+D", decl);
316 error ("cannot allocate an object of abstract type %qT", type);
318 /* Only go through this once. */
319 if (VEC_length (tree, pure))
324 inform ("%J because the following virtual functions are pure "
325 "within %qT:", TYPE_MAIN_DECL (type), type);
327 for (ix = 0; VEC_iterate (tree, pure, ix, fn); ix++)
328 inform ("\t%+#D", fn);
329 /* Now truncate the vector. This leaves it non-null, so we know
330 there are pure virtuals, but empty so we don't list them out
332 VEC_truncate (tree, pure, 0);
335 inform ("%J since type %qT has pure virtual functions",
336 TYPE_MAIN_DECL (type), type);
341 /* Print an error message for invalid use of an incomplete type.
342 VALUE is the expression that was used (or 0 if that isn't known)
343 and TYPE is the type that was invalid. DIAG_TYPE indicates the
344 type of diagnostic: 0 for an error, 1 for a warning, 2 for a
348 cxx_incomplete_type_diagnostic (tree value, tree type, int diag_type)
351 void (*p_msg) (const char *, ...) ATTRIBUTE_GCC_CXXDIAG(1,2);
355 else if (diag_type == 2)
360 /* Avoid duplicate error message. */
361 if (TREE_CODE (type) == ERROR_MARK)
364 if (value != 0 && (TREE_CODE (value) == VAR_DECL
365 || TREE_CODE (value) == PARM_DECL
366 || TREE_CODE (value) == FIELD_DECL))
368 p_msg ("%q+D has incomplete type", value);
372 /* We must print an error message. Be clever about what it says. */
374 switch (TREE_CODE (type))
380 p_msg ("invalid use of incomplete type %q#T", type);
381 if (!TYPE_TEMPLATE_INFO (type))
382 p_msg ("forward declaration of %q+#T", type);
384 p_msg ("declaration of %q+#T", type);
388 p_msg ("invalid use of %qT", type);
392 if (TYPE_DOMAIN (type))
394 type = TREE_TYPE (type);
397 p_msg ("invalid use of array with unspecified bounds");
402 p_msg ("invalid use of member (did you forget the %<&%> ?)");
405 case TEMPLATE_TYPE_PARM:
406 p_msg ("invalid use of template type parameter %qT", type);
409 case BOUND_TEMPLATE_TEMPLATE_PARM:
410 p_msg ("invalid use of template template parameter %qT",
415 p_msg ("invalid use of dependent type %qT", type);
419 if (value && TREE_CODE (value) == COMPONENT_REF)
421 else if (value && TREE_CODE (value) == ADDR_EXPR)
422 p_msg ("address of overloaded function with no contextual "
424 else if (value && TREE_CODE (value) == OVERLOAD)
425 p_msg ("overloaded function with no contextual type information");
427 p_msg ("insufficient contextual information to determine type");
435 /* Backward-compatibility interface to incomplete_type_diagnostic;
436 required by ../tree.c. */
437 #undef cxx_incomplete_type_error
439 cxx_incomplete_type_error (tree value, tree type)
441 cxx_incomplete_type_diagnostic (value, type, 0);
445 /* The recursive part of split_nonconstant_init. DEST is an lvalue
446 expression to which INIT should be assigned. INIT is a CONSTRUCTOR. */
449 split_nonconstant_init_1 (tree dest, tree init)
451 unsigned HOST_WIDE_INT idx;
452 tree field_index, value;
453 tree type = TREE_TYPE (dest);
454 tree inner_type = NULL;
455 bool array_type_p = false;
457 switch (TREE_CODE (type))
460 inner_type = TREE_TYPE (type);
466 case QUAL_UNION_TYPE:
467 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (init), idx,
470 /* The current implementation of this algorithm assumes that
471 the field was set for all the elements. This is usually done
472 by process_init_constructor. */
473 gcc_assert (field_index);
476 inner_type = TREE_TYPE (field_index);
478 if (TREE_CODE (value) == CONSTRUCTOR)
483 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
484 NULL_TREE, NULL_TREE);
486 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
489 split_nonconstant_init_1 (sub, value);
491 else if (!initializer_constant_valid_p (value, inner_type))
496 /* FIXME: Ordered removal is O(1) so the whole function is
497 worst-case quadratic. This could be fixed using an aside
498 bitmap to record which elements must be removed and remove
499 them all at the same time. Or by merging
500 split_non_constant_init into process_init_constructor_array,
501 that is separating constants from non-constants while building
503 VEC_ordered_remove (constructor_elt, CONSTRUCTOR_ELTS (init),
508 sub = build4 (ARRAY_REF, inner_type, dest, field_index,
509 NULL_TREE, NULL_TREE);
511 sub = build3 (COMPONENT_REF, inner_type, dest, field_index,
514 code = build2 (INIT_EXPR, inner_type, sub, value);
515 code = build_stmt (EXPR_STMT, code);
523 if (!initializer_constant_valid_p (init, type))
526 tree cons = copy_node (init);
527 CONSTRUCTOR_ELTS (init) = NULL;
528 code = build2 (MODIFY_EXPR, type, dest, cons);
529 code = build_stmt (EXPR_STMT, code);
538 /* The rest of the initializer is now a constant. */
539 TREE_CONSTANT (init) = 1;
542 /* A subroutine of store_init_value. Splits non-constant static
543 initializer INIT into a constant part and generates code to
544 perform the non-constant part of the initialization to DEST.
545 Returns the code for the runtime init. */
548 split_nonconstant_init (tree dest, tree init)
552 if (TREE_CODE (init) == CONSTRUCTOR)
554 code = push_stmt_list ();
555 split_nonconstant_init_1 (dest, init);
556 code = pop_stmt_list (code);
557 DECL_INITIAL (dest) = init;
558 TREE_READONLY (dest) = 0;
561 code = build2 (INIT_EXPR, TREE_TYPE (dest), dest, init);
566 /* Perform appropriate conversions on the initial value of a variable,
567 store it in the declaration DECL,
568 and print any error messages that are appropriate.
569 If the init is invalid, store an ERROR_MARK.
571 C++: Note that INIT might be a TREE_LIST, which would mean that it is
572 a base class initializer for some aggregate type, hopefully compatible
573 with DECL. If INIT is a single element, and DECL is an aggregate
574 type, we silently convert INIT into a TREE_LIST, allowing a constructor
577 If INIT is a TREE_LIST and there is no constructor, turn INIT
578 into a CONSTRUCTOR and use standard initialization techniques.
579 Perhaps a warning should be generated?
581 Returns code to be executed if initialization could not be performed
582 for static variable. In that case, caller must emit the code. */
585 store_init_value (tree decl, tree init)
589 /* If variable's type was invalidly declared, just ignore it. */
591 type = TREE_TYPE (decl);
592 if (TREE_CODE (type) == ERROR_MARK)
595 if (IS_AGGR_TYPE (type))
597 gcc_assert (TYPE_HAS_TRIVIAL_INIT_REF (type)
598 || TREE_CODE (init) == CONSTRUCTOR);
600 if (TREE_CODE (init) == TREE_LIST)
602 error ("constructor syntax used, but no constructor declared "
603 "for type %qT", type);
604 init = build_constructor_from_list (NULL_TREE, nreverse (init));
607 else if (TREE_CODE (init) == TREE_LIST
608 && TREE_TYPE (init) != unknown_type_node)
610 if (TREE_CODE (decl) == RESULT_DECL)
611 init = build_x_compound_expr_from_list (init,
612 "return value initializer");
613 else if (TREE_CODE (init) == TREE_LIST
614 && TREE_CODE (TREE_TYPE (decl)) == ARRAY_TYPE)
616 error ("cannot initialize arrays using this syntax");
620 /* We get here with code like `int a (2);' */
621 init = build_x_compound_expr_from_list (init, "initializer");
624 /* End of special C++ code. */
626 /* Digest the specified initializer into an expression. */
627 value = digest_init (type, init);
628 /* If the initializer is not a constant, fill in DECL_INITIAL with
629 the bits that are constant, and then return an expression that
630 will perform the dynamic initialization. */
631 if (value != error_mark_node
632 && (TREE_SIDE_EFFECTS (value)
633 || ! initializer_constant_valid_p (value, TREE_TYPE (value))))
634 return split_nonconstant_init (decl, value);
635 /* If the value is a constant, just put it in DECL_INITIAL. If DECL
636 is an automatic variable, the middle end will turn this into a
637 dynamic initialization later. */
638 DECL_INITIAL (decl) = value;
643 /* Process the initializer INIT for a variable of type TYPE, emitting
644 diagnostics for invalid initializers and converting the initializer as
647 For aggregate types, it assumes that reshape_init has already run, thus the
648 initializer will have the right shape (brace elision has been undone). */
651 digest_init (tree type, tree init)
653 enum tree_code code = TREE_CODE (type);
655 if (init == error_mark_node)
656 return error_mark_node;
660 /* We must strip the outermost array type when completing the type,
661 because the its bounds might be incomplete at the moment. */
662 if (!complete_type_or_else (TREE_CODE (type) == ARRAY_TYPE
663 ? TREE_TYPE (type) : type, NULL_TREE))
664 return error_mark_node;
666 /* Strip NON_LVALUE_EXPRs since we aren't using as an lvalue
667 (g++.old-deja/g++.law/casts2.C). */
668 if (TREE_CODE (init) == NON_LVALUE_EXPR)
669 init = TREE_OPERAND (init, 0);
671 /* Initialization of an array of chars from a string constant. The initializer
672 can be optionally enclosed in braces, but reshape_init has already removed
673 them if they were present. */
674 if (code == ARRAY_TYPE)
676 tree typ1 = TYPE_MAIN_VARIANT (TREE_TYPE (type));
677 if (char_type_p (typ1)
679 && TREE_CODE (init) == STRING_CST)
681 tree char_type = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (init)));
683 if (char_type != char_type_node
684 && TYPE_PRECISION (typ1) == BITS_PER_UNIT)
686 error ("char-array initialized from wide string");
687 return error_mark_node;
689 if (char_type == char_type_node
690 && TYPE_PRECISION (typ1) != BITS_PER_UNIT)
692 error ("int-array initialized from non-wide string");
693 return error_mark_node;
696 TREE_TYPE (init) = type;
697 if (TYPE_DOMAIN (type) != 0 && TREE_CONSTANT (TYPE_SIZE (type)))
699 int size = TREE_INT_CST_LOW (TYPE_SIZE (type));
700 size = (size + BITS_PER_UNIT - 1) / BITS_PER_UNIT;
701 /* In C it is ok to subtract 1 from the length of the string
702 because it's ok to ignore the terminating null char that is
703 counted in the length of the constant, but in C++ this would
705 if (size < TREE_STRING_LENGTH (init))
706 pedwarn ("initializer-string for array of chars is too long");
712 /* Handle scalar types (including conversions) and references. */
713 if (TREE_CODE (type) != COMPLEX_TYPE
714 && (SCALAR_TYPE_P (type) || code == REFERENCE_TYPE))
715 return convert_for_initialization (0, type, init, LOOKUP_NORMAL,
716 "initialization", NULL_TREE, 0);
718 /* Come here only for aggregates: records, arrays, unions, complex numbers
720 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
721 || TREE_CODE (type) == VECTOR_TYPE
722 || TREE_CODE (type) == RECORD_TYPE
723 || TREE_CODE (type) == UNION_TYPE
724 || TREE_CODE (type) == COMPLEX_TYPE);
726 if (BRACE_ENCLOSED_INITIALIZER_P (init))
727 return process_init_constructor (type, init);
730 if (COMPOUND_LITERAL_P (init) && TREE_CODE (type) == ARRAY_TYPE)
732 error ("cannot initialize aggregate of type %qT with "
733 "a compound literal", type);
735 return error_mark_node;
738 if (TREE_CODE (type) == ARRAY_TYPE
739 && TREE_CODE (init) != CONSTRUCTOR)
741 error ("array must be initialized with a brace-enclosed"
743 return error_mark_node;
746 return convert_for_initialization (NULL_TREE, type, init,
747 LOOKUP_NORMAL | LOOKUP_ONLYCONVERTING,
748 "initialization", NULL_TREE, 0);
753 /* Set of flags used within process_init_constructor to describe the
755 #define PICFLAG_ERRONEOUS 1
756 #define PICFLAG_NOT_ALL_CONSTANT 2
757 #define PICFLAG_NOT_ALL_SIMPLE 4
759 /* Given an initializer INIT, return the flag (PICFLAG_*) which better
763 picflag_from_initializer (tree init)
765 if (init == error_mark_node)
766 return PICFLAG_ERRONEOUS;
767 else if (!TREE_CONSTANT (init))
768 return PICFLAG_NOT_ALL_CONSTANT;
769 else if (!initializer_constant_valid_p (init, TREE_TYPE (init)))
770 return PICFLAG_NOT_ALL_SIMPLE;
774 /* Subroutine of process_init_constructor, which will process an initializer
775 INIT for a array or vector of type TYPE. Returns the flags (PICFLAG_*) which
776 describe the initializers. */
779 process_init_constructor_array (tree type, tree init)
781 unsigned HOST_WIDE_INT i, len = 0;
783 bool unbounded = false;
785 VEC(constructor_elt,gc) *v = CONSTRUCTOR_ELTS (init);
787 gcc_assert (TREE_CODE (type) == ARRAY_TYPE
788 || TREE_CODE (type) == VECTOR_TYPE);
790 if (TREE_CODE (type) == ARRAY_TYPE)
792 tree domain = TYPE_DOMAIN (type);
794 len = (TREE_INT_CST_LOW (TYPE_MAX_VALUE (domain))
795 - TREE_INT_CST_LOW (TYPE_MIN_VALUE (domain))
798 unbounded = true; /* Take as many as there are. */
801 /* Vectors are like simple fixed-size arrays. */
802 len = TYPE_VECTOR_SUBPARTS (type);
804 /* There cannot be more initializers than needed as otherwise
805 reshape_init would have already rejected the initializer. */
807 gcc_assert (VEC_length (constructor_elt, v) <= len);
809 for (i = 0; VEC_iterate (constructor_elt, v, i, ce); ++i)
813 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST);
814 if (compare_tree_int (ce->index, i) != 0)
816 ce->value = error_mark_node;
817 sorry ("non-trivial designated initializers not supported");
821 ce->index = size_int (i);
822 gcc_assert (ce->value);
823 ce->value = digest_init (TREE_TYPE (type), ce->value);
825 if (ce->value != error_mark_node)
826 gcc_assert (same_type_ignoring_top_level_qualifiers_p
827 (TREE_TYPE (type), TREE_TYPE (ce->value)));
829 flags |= picflag_from_initializer (ce->value);
832 /* No more initializers. If the array is unbounded, we are done. Otherwise,
833 we must add initializers ourselves. */
839 if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (type)))
841 /* If this type needs constructors run for default-initialization,
842 we can't rely on the backend to do it for us, so build up
843 TARGET_EXPRs. If the type in question is a class, just build
844 one up; if it's an array, recurse. */
845 if (IS_AGGR_TYPE (TREE_TYPE (type)))
846 next = build_functional_cast (TREE_TYPE (type), NULL_TREE);
848 next = build_constructor (NULL_TREE, NULL);
849 next = digest_init (TREE_TYPE (type), next);
851 else if (!zero_init_p (TREE_TYPE (type)))
852 next = build_zero_init (TREE_TYPE (type),
854 /*static_storage_p=*/false);
856 /* The default zero-initialization is fine for us; don't
857 add anything to the CONSTRUCTOR. */
860 flags |= picflag_from_initializer (next);
861 CONSTRUCTOR_APPEND_ELT (v, size_int (i), next);
864 CONSTRUCTOR_ELTS (init) = v;
868 /* Subroutine of process_init_constructor, which will process an initializer
869 INIT for a class of type TYPE. Returns the flags (PICFLAG_*) which describe
873 process_init_constructor_record (tree type, tree init)
875 VEC(constructor_elt,gc) *v = NULL;
878 unsigned HOST_WIDE_INT idx = 0;
880 gcc_assert (TREE_CODE (type) == RECORD_TYPE);
881 gcc_assert (!CLASSTYPE_VBASECLASSES (type));
882 gcc_assert (!TYPE_BINFO (type)
883 || !BINFO_N_BASE_BINFOS (TYPE_BINFO (type)));
884 gcc_assert (!TYPE_POLYMORPHIC_P (type));
886 /* Generally, we will always have an index for each initializer (which is
887 a FIELD_DECL, put by reshape_init), but compound literals don't go trough
888 reshape_init. So we need to handle both cases. */
889 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
893 if (!DECL_NAME (field) && DECL_C_BIT_FIELD (field))
895 flags |= picflag_from_initializer (integer_zero_node);
896 CONSTRUCTOR_APPEND_ELT (v, field, integer_zero_node);
900 if (TREE_CODE (field) != FIELD_DECL || DECL_ARTIFICIAL (field))
903 if (idx < VEC_length (constructor_elt, CONSTRUCTOR_ELTS (init)))
905 constructor_elt *ce = VEC_index (constructor_elt,
906 CONSTRUCTOR_ELTS (init), idx);
909 /* We can have either a FIELD_DECL or an IDENTIFIER_NODE. The
910 latter case can happen in templates where lookup has to be
912 gcc_assert (TREE_CODE (ce->index) == FIELD_DECL
913 || TREE_CODE (ce->index) == IDENTIFIER_NODE);
914 if (ce->index != field
915 && ce->index != DECL_NAME (field))
917 ce->value = error_mark_node;
918 sorry ("non-trivial designated initializers not supported");
922 gcc_assert (ce->value);
923 next = digest_init (TREE_TYPE (field), ce->value);
926 else if (TYPE_NEEDS_CONSTRUCTING (TREE_TYPE (field)))
928 /* If this type needs constructors run for
929 default-initialization, we can't rely on the backend to do it
930 for us, so build up TARGET_EXPRs. If the type in question is
931 a class, just build one up; if it's an array, recurse. */
932 if (IS_AGGR_TYPE (TREE_TYPE (field)))
933 next = build_functional_cast (TREE_TYPE (field), NULL_TREE);
935 next = build_constructor (NULL_TREE, NULL);
937 next = digest_init (TREE_TYPE (field), next);
939 /* Warn when some struct elements are implicitly initialized. */
940 warning (OPT_Wmissing_field_initializers,
941 "missing initializer for member %qD", field);
945 if (TREE_READONLY (field))
946 error ("uninitialized const member %qD", field);
947 else if (CLASSTYPE_READONLY_FIELDS_NEED_INIT (TREE_TYPE (field)))
948 error ("member %qD with uninitialized const fields", field);
949 else if (TREE_CODE (TREE_TYPE (field)) == REFERENCE_TYPE)
950 error ("member %qD is uninitialized reference", field);
952 /* Warn when some struct elements are implicitly initialized
954 warning (OPT_Wmissing_field_initializers,
955 "missing initializer for member %qD", field);
957 if (!zero_init_p (TREE_TYPE (field)))
958 next = build_zero_init (TREE_TYPE (field), /*nelts=*/NULL_TREE,
959 /*static_storage_p=*/false);
961 /* The default zero-initialization is fine for us; don't
962 add anything to the CONSTRUCTOR. */
966 flags |= picflag_from_initializer (next);
967 CONSTRUCTOR_APPEND_ELT (v, field, next);
970 CONSTRUCTOR_ELTS (init) = v;
974 /* Subroutine of process_init_constructor, which will process a single
975 initializer INIT for a union of type TYPE. Returns the flags (PICFLAG_*)
976 which describe the initializer. */
979 process_init_constructor_union (tree type, tree init)
983 /* If the initializer was empty, use default zero initialization. */
984 if (VEC_empty (constructor_elt, CONSTRUCTOR_ELTS (init)))
987 gcc_assert (VEC_length (constructor_elt, CONSTRUCTOR_ELTS (init)) == 1);
988 ce = VEC_index (constructor_elt, CONSTRUCTOR_ELTS (init), 0);
990 /* If this element specifies a field, initialize via that field. */
993 if (TREE_CODE (ce->index) == FIELD_DECL)
995 else if (TREE_CODE (ce->index) == IDENTIFIER_NODE)
997 /* This can happen within a cast, see g++.dg/opt/cse2.C. */
998 tree name = ce->index;
1000 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
1001 if (DECL_NAME (field) == name)
1005 error ("no field %qD found in union being initialized", field);
1006 ce->value = error_mark_node;
1012 gcc_assert (TREE_CODE (ce->index) == INTEGER_CST
1013 || TREE_CODE (ce->index) == RANGE_EXPR);
1014 error ("index value instead of field name in union initializer");
1015 ce->value = error_mark_node;
1020 /* Find the first named field. ANSI decided in September 1990
1021 that only named fields count here. */
1022 tree field = TYPE_FIELDS (type);
1023 while (field && (!DECL_NAME (field) || TREE_CODE (field) != FIELD_DECL))
1024 field = TREE_CHAIN (field);
1029 if (ce->value && ce->value != error_mark_node)
1030 ce->value = digest_init (TREE_TYPE (ce->index), ce->value);
1032 return picflag_from_initializer (ce->value);
1035 /* Process INIT, a constructor for a variable of aggregate type TYPE. The
1036 constructor is a brace-enclosed initializer, and will be modified in-place.
1038 Each element is converted to the right type through digest_init, and
1039 missing initializers are added following the language rules (zero-padding,
1042 After the execution, the initializer will have TREE_CONSTANT if all elts are
1043 constant, and TREE_STATIC set if, in addition, all elts are simple enough
1044 constants that the assembler and linker can compute them.
1046 The function returns the initializer itself, or error_mark_node in case
1050 process_init_constructor (tree type, tree init)
1054 gcc_assert (BRACE_ENCLOSED_INITIALIZER_P (init));
1056 if (TREE_CODE (type) == ARRAY_TYPE || TREE_CODE (type) == VECTOR_TYPE)
1057 flags = process_init_constructor_array (type, init);
1058 else if (TREE_CODE (type) == RECORD_TYPE)
1059 flags = process_init_constructor_record (type, init);
1060 else if (TREE_CODE (type) == UNION_TYPE)
1061 flags = process_init_constructor_union (type, init);
1065 if (flags & PICFLAG_ERRONEOUS)
1066 return error_mark_node;
1068 TREE_TYPE (init) = type;
1069 if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type) == NULL_TREE)
1070 cp_complete_array_type (&TREE_TYPE (init), init, /*do_default=*/0);
1071 if (!(flags & PICFLAG_NOT_ALL_CONSTANT))
1073 TREE_CONSTANT (init) = 1;
1074 TREE_INVARIANT (init) = 1;
1075 if (!(flags & PICFLAG_NOT_ALL_SIMPLE))
1076 TREE_STATIC (init) = 1;
1081 /* Given a structure or union value DATUM, construct and return
1082 the structure or union component which results from narrowing
1083 that value to the base specified in BASETYPE. For example, given the
1086 class L { int ii; };
1087 class A : L { ... };
1088 class B : L { ... };
1089 class C : A, B { ... };
1097 x.A::ii refers to the ii member of the L part of
1098 the A part of the C object named by X. In this case,
1099 DATUM would be x, and BASETYPE would be A.
1101 I used to think that this was nonconformant, that the standard specified
1102 that first we look up ii in A, then convert x to an L& and pull out the
1103 ii part. But in fact, it does say that we convert x to an A&; A here
1104 is known as the "naming class". (jason 2000-12-19)
1106 BINFO_P points to a variable initialized either to NULL_TREE or to the
1107 binfo for the specific base subobject we want to convert to. */
1110 build_scoped_ref (tree datum, tree basetype, tree* binfo_p)
1114 if (datum == error_mark_node)
1115 return error_mark_node;
1119 binfo = lookup_base (TREE_TYPE (datum), basetype, ba_check, NULL);
1121 if (!binfo || binfo == error_mark_node)
1123 *binfo_p = NULL_TREE;
1125 error_not_base_type (basetype, TREE_TYPE (datum));
1126 return error_mark_node;
1130 return build_base_path (PLUS_EXPR, datum, binfo, 1);
1133 /* Build a reference to an object specified by the C++ `->' operator.
1134 Usually this just involves dereferencing the object, but if the
1135 `->' operator is overloaded, then such overloads must be
1136 performed until an object which does not have the `->' operator
1137 overloaded is found. An error is reported when circular pointer
1138 delegation is detected. */
1141 build_x_arrow (tree expr)
1143 tree orig_expr = expr;
1144 tree types_memoized = NULL_TREE;
1145 tree type = TREE_TYPE (expr);
1146 tree last_rval = NULL_TREE;
1148 if (type == error_mark_node)
1149 return error_mark_node;
1151 if (processing_template_decl)
1153 if (type_dependent_expression_p (expr))
1154 return build_min_nt (ARROW_EXPR, expr);
1155 expr = build_non_dependent_expr (expr);
1158 if (IS_AGGR_TYPE (type))
1160 while ((expr = build_new_op (COMPONENT_REF, LOOKUP_NORMAL, expr,
1161 NULL_TREE, NULL_TREE,
1162 /*overloaded_p=*/NULL)))
1164 if (expr == error_mark_node)
1165 return error_mark_node;
1167 if (value_member (TREE_TYPE (expr), types_memoized))
1169 error ("circular pointer delegation detected");
1170 return error_mark_node;
1174 types_memoized = tree_cons (NULL_TREE, TREE_TYPE (expr),
1180 if (last_rval == NULL_TREE)
1182 error ("base operand of %<->%> has non-pointer type %qT", type);
1183 return error_mark_node;
1186 if (TREE_CODE (TREE_TYPE (last_rval)) == REFERENCE_TYPE)
1187 last_rval = convert_from_reference (last_rval);
1190 last_rval = decay_conversion (expr);
1192 if (TREE_CODE (TREE_TYPE (last_rval)) == POINTER_TYPE)
1194 if (processing_template_decl)
1196 expr = build_min_non_dep (ARROW_EXPR, last_rval, orig_expr);
1197 /* It will be dereferenced. */
1198 TREE_TYPE (expr) = TREE_TYPE (TREE_TYPE (last_rval));
1202 return build_indirect_ref (last_rval, NULL);
1206 error ("result of %<operator->()%> yields non-pointer result");
1208 error ("base operand of %<->%> is not a pointer");
1209 return error_mark_node;
1212 /* Return an expression for "DATUM .* COMPONENT". DATUM has not
1213 already been checked out to be of aggregate type. */
1216 build_m_component_ref (tree datum, tree component)
1224 if (error_operand_p (datum) || error_operand_p (component))
1225 return error_mark_node;
1227 ptrmem_type = TREE_TYPE (component);
1228 if (!TYPE_PTR_TO_MEMBER_P (ptrmem_type))
1230 error ("%qE cannot be used as a member pointer, since it is of "
1232 component, ptrmem_type);
1233 return error_mark_node;
1236 objtype = TYPE_MAIN_VARIANT (TREE_TYPE (datum));
1237 if (! IS_AGGR_TYPE (objtype))
1239 error ("cannot apply member pointer %qE to %qE, which is of "
1240 "non-class type %qT",
1241 component, datum, objtype);
1242 return error_mark_node;
1245 type = TYPE_PTRMEM_POINTED_TO_TYPE (ptrmem_type);
1246 ctype = complete_type (TYPE_PTRMEM_CLASS_TYPE (ptrmem_type));
1248 if (!COMPLETE_TYPE_P (ctype))
1250 if (!same_type_p (ctype, objtype))
1256 binfo = lookup_base (objtype, ctype, ba_check, NULL);
1261 error ("pointer to member type %qT incompatible with object "
1264 return error_mark_node;
1266 else if (binfo == error_mark_node)
1267 return error_mark_node;
1270 if (TYPE_PTRMEM_P (ptrmem_type))
1272 /* Compute the type of the field, as described in [expr.ref].
1273 There's no such thing as a mutable pointer-to-member, so
1274 things are not as complex as they are for references to
1275 non-static data members. */
1276 type = cp_build_qualified_type (type,
1277 (cp_type_quals (type)
1278 | cp_type_quals (TREE_TYPE (datum))));
1280 datum = build_address (datum);
1282 /* Convert object to the correct base. */
1284 datum = build_base_path (PLUS_EXPR, datum, binfo, 1);
1286 /* Build an expression for "object + offset" where offset is the
1287 value stored in the pointer-to-data-member. */
1288 datum = build2 (PLUS_EXPR, build_pointer_type (type),
1289 datum, build_nop (ptrdiff_type_node, component));
1290 return build_indirect_ref (datum, 0);
1293 return build2 (OFFSET_REF, type, datum, component);
1296 /* Return a tree node for the expression TYPENAME '(' PARMS ')'. */
1299 build_functional_cast (tree exp, tree parms)
1301 /* This is either a call to a constructor,
1302 or a C cast in C++'s `functional' notation. */
1305 if (exp == error_mark_node || parms == error_mark_node)
1306 return error_mark_node;
1308 if (TREE_CODE (exp) == TYPE_DECL)
1309 type = TREE_TYPE (exp);
1313 if (processing_template_decl)
1315 tree t = build_min (CAST_EXPR, type, parms);
1316 /* We don't know if it will or will not have side effects. */
1317 TREE_SIDE_EFFECTS (t) = 1;
1321 if (! IS_AGGR_TYPE (type))
1323 if (parms == NULL_TREE)
1324 return cp_convert (type, integer_zero_node);
1326 /* This must build a C cast. */
1327 parms = build_x_compound_expr_from_list (parms, "functional cast");
1328 return build_c_cast (type, parms);
1331 /* Prepare to evaluate as a call to a constructor. If this expression
1332 is actually used, for example,
1334 return X (arg1, arg2, ...);
1336 then the slot being initialized will be filled in. */
1338 if (!complete_type_or_else (type, NULL_TREE))
1339 return error_mark_node;
1340 if (abstract_virtuals_error (NULL_TREE, type))
1341 return error_mark_node;
1343 if (parms && TREE_CHAIN (parms) == NULL_TREE)
1344 return build_c_cast (type, TREE_VALUE (parms));
1346 /* We need to zero-initialize POD types. */
1347 if (parms == NULL_TREE
1348 && !CLASSTYPE_NON_POD_P (type)
1349 && TYPE_HAS_DEFAULT_CONSTRUCTOR (type))
1351 exp = build_zero_init (type,
1352 /*nelts=*/NULL_TREE,
1353 /*static_storage_p=*/false);
1354 return get_target_expr (exp);
1357 exp = build_special_member_call (NULL_TREE, complete_ctor_identifier, parms,
1358 type, LOOKUP_NORMAL);
1360 if (exp == error_mark_node)
1361 return error_mark_node;
1363 return build_cplus_new (type, exp);
1367 /* Add new exception specifier SPEC, to the LIST we currently have.
1368 If it's already in LIST then do nothing.
1369 Moan if it's bad and we're allowed to. COMPLAIN < 0 means we
1370 know what we're doing. */
1373 add_exception_specifier (tree list, tree spec, int complain)
1378 int diag_type = -1; /* none */
1380 if (spec == error_mark_node)
1383 gcc_assert (spec && (!list || TREE_VALUE (list)));
1385 /* [except.spec] 1, type in an exception specifier shall not be
1386 incomplete, or pointer or ref to incomplete other than pointer
1388 is_ptr = TREE_CODE (core) == POINTER_TYPE;
1389 if (is_ptr || TREE_CODE (core) == REFERENCE_TYPE)
1390 core = TREE_TYPE (core);
1393 else if (VOID_TYPE_P (core))
1395 else if (TREE_CODE (core) == TEMPLATE_TYPE_PARM)
1397 else if (processing_template_decl)
1402 /* 15.4/1 says that types in an exception specifier must be complete,
1403 but it seems more reasonable to only require this on definitions
1404 and calls. So just give a pedwarn at this point; we will give an
1405 error later if we hit one of those two cases. */
1406 if (!COMPLETE_TYPE_P (complete_type (core)))
1407 diag_type = 2; /* pedwarn */
1414 for (probe = list; probe; probe = TREE_CHAIN (probe))
1415 if (same_type_p (TREE_VALUE (probe), spec))
1418 list = tree_cons (NULL_TREE, spec, list);
1421 diag_type = 0; /* error */
1423 if (diag_type >= 0 && complain)
1424 cxx_incomplete_type_diagnostic (NULL_TREE, core, diag_type);
1429 /* Combine the two exceptions specifier lists LIST and ADD, and return
1433 merge_exception_specifiers (tree list, tree add)
1437 else if (!TREE_VALUE (list))
1439 else if (!TREE_VALUE (add))
1443 tree orig_list = list;
1445 for (; add; add = TREE_CHAIN (add))
1447 tree spec = TREE_VALUE (add);
1450 for (probe = orig_list; probe; probe = TREE_CHAIN (probe))
1451 if (same_type_p (TREE_VALUE (probe), spec))
1455 spec = build_tree_list (NULL_TREE, spec);
1456 TREE_CHAIN (spec) = list;
1464 /* Subroutine of build_call. Ensure that each of the types in the
1465 exception specification is complete. Technically, 15.4/1 says that
1466 they need to be complete when we see a declaration of the function,
1467 but we should be able to get away with only requiring this when the
1468 function is defined or called. See also add_exception_specifier. */
1471 require_complete_eh_spec_types (tree fntype, tree decl)
1474 /* Don't complain about calls to op new. */
1475 if (decl && DECL_ARTIFICIAL (decl))
1477 for (raises = TYPE_RAISES_EXCEPTIONS (fntype); raises;
1478 raises = TREE_CHAIN (raises))
1480 tree type = TREE_VALUE (raises);
1481 if (type && !COMPLETE_TYPE_P (type))
1485 ("call to function %qD which throws incomplete type %q#T",
1488 error ("call to function which throws incomplete type %q#T",
1495 #include "gt-cp-typeck2.h"