1 /* Breadth-first and depth-first routines for
2 searching multiple-inheritance lattice for GNU C++.
3 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2002, 2003 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* High-level class interface. */
28 #include "coretypes.h"
39 /* Obstack used for remembering decision points of breadth-first. */
41 static struct obstack search_obstack;
43 /* Methods for pushing and popping objects to and from obstacks. */
46 push_stack_level (obstack, tp, size)
47 struct obstack *obstack;
48 char *tp; /* Sony NewsOS 5.0 compiler doesn't like void * here. */
51 struct stack_level *stack;
52 obstack_grow (obstack, tp, size);
53 stack = (struct stack_level *) ((char*)obstack_next_free (obstack) - size);
54 obstack_finish (obstack);
55 stack->obstack = obstack;
56 stack->first = (tree *) obstack_base (obstack);
57 stack->limit = obstack_room (obstack) / sizeof (tree *);
62 pop_stack_level (stack)
63 struct stack_level *stack;
65 struct stack_level *tem = stack;
66 struct obstack *obstack = tem->obstack;
68 obstack_free (obstack, tem);
72 #define search_level stack_level
73 static struct search_level *search_stack;
77 /* The class dominating the hierarchy. */
79 /* A pointer to a complete object of the indicated TYPE. */
84 static tree lookup_field_1 (tree, tree);
85 static tree dfs_check_overlap (tree, void *);
86 static tree dfs_no_overlap_yet (tree, int, void *);
87 static base_kind lookup_base_r (tree, tree, base_access,
88 bool, bool, bool, tree *);
89 static int dynamic_cast_base_recurse (tree, tree, bool, tree *);
90 static tree marked_pushdecls_p (tree, int, void *);
91 static tree unmarked_pushdecls_p (tree, int, void *);
92 static tree dfs_debug_unmarkedp (tree, int, void *);
93 static tree dfs_debug_mark (tree, void *);
94 static tree dfs_push_type_decls (tree, void *);
95 static tree dfs_push_decls (tree, void *);
96 static tree dfs_unuse_fields (tree, void *);
97 static tree add_conversions (tree, void *);
98 static int look_for_overrides_r (tree, tree);
99 static struct search_level *push_search_level (struct stack_level *,
101 static struct search_level *pop_search_level (struct stack_level *);
102 static tree bfs_walk (tree, tree (*) (tree, void *),
103 tree (*) (tree, int, void *), void *);
104 static tree lookup_field_queue_p (tree, int, void *);
105 static int shared_member_p (tree);
106 static tree lookup_field_r (tree, void *);
107 static tree dfs_accessible_queue_p (tree, int, void *);
108 static tree dfs_accessible_p (tree, void *);
109 static tree dfs_access_in_type (tree, void *);
110 static access_kind access_in_type (tree, tree);
111 static int protected_accessible_p (tree, tree, tree);
112 static int friend_accessible_p (tree, tree, tree);
113 static void setup_class_bindings (tree, int);
114 static int template_self_reference_p (tree, tree);
115 static tree dfs_get_pure_virtuals (tree, void *);
117 /* Allocate a level of searching. */
119 static struct search_level *
120 push_search_level (struct stack_level *stack, struct obstack *obstack)
122 struct search_level tem;
125 return push_stack_level (obstack, (char *)&tem, sizeof (tem));
128 /* Discard a level of search allocation. */
130 static struct search_level *
131 pop_search_level (struct stack_level *obstack)
133 register struct search_level *stack = pop_stack_level (obstack);
138 /* Variables for gathering statistics. */
139 #ifdef GATHER_STATISTICS
140 static int n_fields_searched;
141 static int n_calls_lookup_field, n_calls_lookup_field_1;
142 static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1;
143 static int n_calls_get_base_type;
144 static int n_outer_fields_searched;
145 static int n_contexts_saved;
146 #endif /* GATHER_STATISTICS */
149 /* Worker for lookup_base. BINFO is the binfo we are searching at,
150 BASE is the RECORD_TYPE we are searching for. ACCESS is the
151 required access checks. WITHIN_CURRENT_SCOPE, IS_NON_PUBLIC and
152 IS_VIRTUAL indicate how BINFO was reached from the start of the
153 search. WITHIN_CURRENT_SCOPE is true if we met the current scope,
154 or friend thereof (this allows us to determine whether a protected
155 base is accessible or not). IS_NON_PUBLIC indicates whether BINFO
156 is accessible and IS_VIRTUAL indicates if it is morally virtual.
158 If BINFO is of the required type, then *BINFO_PTR is examined to
159 compare with any other instance of BASE we might have already
160 discovered. *BINFO_PTR is initialized and a base_kind return value
161 indicates what kind of base was located.
163 Otherwise BINFO's bases are searched. */
166 lookup_base_r (tree binfo, tree base, base_access access,
167 bool within_current_scope,
168 bool is_non_public, /* inside a non-public part */
169 bool is_virtual, /* inside a virtual part */
173 tree bases, accesses;
174 base_kind found = bk_not_base;
176 if (access == ba_check
177 && !within_current_scope
178 && is_friend (BINFO_TYPE (binfo), current_scope ()))
180 /* Do not clear is_non_public here. If A is a private base of B, A
181 is not allowed to convert a B* to an A*. */
182 within_current_scope = 1;
185 if (same_type_p (BINFO_TYPE (binfo), base))
187 /* We have found a base. Check against what we have found
189 found = bk_same_type;
191 found = bk_via_virtual;
193 found = bk_inaccessible;
197 else if (binfo != *binfo_ptr)
199 if (access != ba_any)
201 else if (!is_virtual)
202 /* Prefer a non-virtual base. */
210 bases = BINFO_BASETYPES (binfo);
211 accesses = BINFO_BASEACCESSES (binfo);
215 for (i = TREE_VEC_LENGTH (bases); i--;)
217 tree base_binfo = TREE_VEC_ELT (bases, i);
218 tree base_access = TREE_VEC_ELT (accesses, i);
220 int this_non_public = is_non_public;
221 int this_virtual = is_virtual;
224 if (access <= ba_ignore)
226 else if (base_access == access_public_node)
228 else if (access == ba_not_special)
230 else if (base_access == access_protected_node && within_current_scope)
232 else if (is_friend (BINFO_TYPE (binfo), current_scope ()))
237 if (TREE_VIA_VIRTUAL (base_binfo))
240 bk = lookup_base_r (base_binfo, base,
241 access, within_current_scope,
242 this_non_public, this_virtual,
248 if (access != ba_any)
253 case bk_inaccessible:
254 if (found == bk_not_base)
256 my_friendly_assert (found == bk_via_virtual
257 || found == bk_inaccessible, 20010723);
265 my_friendly_assert (found == bk_not_base, 20010723);
270 if (found != bk_ambig)
281 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
282 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
283 non-NULL, fill with information about what kind of base we
286 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
287 not set in ACCESS, then an error is issued and error_mark_node is
288 returned. If the ba_quiet bit is set, then no error is issued and
289 NULL_TREE is returned. */
292 lookup_base (tree t, tree base, base_access access, base_kind *kind_ptr)
294 tree binfo = NULL; /* The binfo we've found so far. */
298 if (t == error_mark_node || base == error_mark_node)
301 *kind_ptr = bk_not_base;
302 return error_mark_node;
304 my_friendly_assert (TYPE_P (base), 20011127);
312 t_binfo = TYPE_BINFO (t);
314 /* Ensure that the types are instantiated. */
315 t = complete_type (TYPE_MAIN_VARIANT (t));
316 base = complete_type (TYPE_MAIN_VARIANT (base));
318 bk = lookup_base_r (t_binfo, base, access & ~ba_quiet,
323 case bk_inaccessible:
325 if (!(access & ba_quiet))
327 error ("`%T' is an inaccessible base of `%T'", base, t);
328 binfo = error_mark_node;
332 if (access != ba_any)
335 if (!(access & ba_quiet))
337 error ("`%T' is an ambiguous base of `%T'", base, t);
338 binfo = error_mark_node;
351 /* Worker function for get_dynamic_cast_base_type. */
354 dynamic_cast_base_recurse (tree subtype, tree binfo, bool is_via_virtual,
357 tree binfos, accesses;
361 if (BINFO_TYPE (binfo) == subtype)
367 *offset_ptr = BINFO_OFFSET (binfo);
372 binfos = BINFO_BASETYPES (binfo);
373 accesses = BINFO_BASEACCESSES (binfo);
374 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
375 for (i = 0; i < n_baselinks; i++)
377 tree base_binfo = TREE_VEC_ELT (binfos, i);
378 tree base_access = TREE_VEC_ELT (accesses, i);
381 if (base_access != access_public_node)
383 rval = dynamic_cast_base_recurse
384 (subtype, base_binfo,
385 is_via_virtual || TREE_VIA_VIRTUAL (base_binfo), offset_ptr);
389 worst = worst >= 0 ? -3 : worst;
392 else if (rval == -3 && worst != -1)
398 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
399 started from is related to the required TARGET type, in order to optimize
400 the inheritance graph search. This information is independent of the
401 current context, and ignores private paths, hence get_base_distance is
402 inappropriate. Return a TREE specifying the base offset, BOFF.
403 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
404 and there are no public virtual SUBTYPE bases.
405 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
406 BOFF == -2, SUBTYPE is not a public base.
407 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
410 get_dynamic_cast_base_type (tree subtype, tree target)
412 tree offset = NULL_TREE;
413 int boff = dynamic_cast_base_recurse (subtype, TYPE_BINFO (target),
418 offset = build_int_2 (boff, -1);
419 TREE_TYPE (offset) = ssizetype;
423 /* Search for a member with name NAME in a multiple inheritance lattice
424 specified by TYPE. If it does not exist, return NULL_TREE.
425 If the member is ambiguously referenced, return `error_mark_node'.
426 Otherwise, return the FIELD_DECL. */
428 /* Do a 1-level search for NAME as a member of TYPE. The caller must
429 figure out whether it can access this field. (Since it is only one
430 level, this is reasonable.) */
433 lookup_field_1 (tree type, tree name)
437 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
438 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM
439 || TREE_CODE (type) == TYPENAME_TYPE)
440 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
441 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
442 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
443 the code often worked even when we treated the index as a list
445 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
449 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
450 && DECL_SORTED_FIELDS (TYPE_NAME (type)))
452 tree *fields = &TREE_VEC_ELT (DECL_SORTED_FIELDS (TYPE_NAME (type)), 0);
453 int lo = 0, hi = TREE_VEC_LENGTH (DECL_SORTED_FIELDS (TYPE_NAME (type)));
460 #ifdef GATHER_STATISTICS
462 #endif /* GATHER_STATISTICS */
464 if (DECL_NAME (fields[i]) > name)
466 else if (DECL_NAME (fields[i]) < name)
470 /* We might have a nested class and a field with the
471 same name; we sorted them appropriately via
472 field_decl_cmp, so just look for the last field with
475 && DECL_NAME (fields[i+1]) == name)
483 field = TYPE_FIELDS (type);
485 #ifdef GATHER_STATISTICS
486 n_calls_lookup_field_1++;
487 #endif /* GATHER_STATISTICS */
490 #ifdef GATHER_STATISTICS
492 #endif /* GATHER_STATISTICS */
493 my_friendly_assert (DECL_P (field), 0);
494 if (DECL_NAME (field) == NULL_TREE
495 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
497 tree temp = lookup_field_1 (TREE_TYPE (field), name);
501 if (TREE_CODE (field) == USING_DECL)
502 /* For now, we're just treating member using declarations as
503 old ARM-style access declarations. Thus, there's no reason
504 to return a USING_DECL, and the rest of the compiler can't
505 handle it. Once the class is defined, these are purged
506 from TYPE_FIELDS anyhow; see handle_using_decl. */
508 else if (DECL_NAME (field) == name)
510 field = TREE_CHAIN (field);
513 if (name == vptr_identifier)
515 /* Give the user what s/he thinks s/he wants. */
516 if (TYPE_POLYMORPHIC_P (type))
517 return TYPE_VFIELD (type);
522 /* There are a number of cases we need to be aware of here:
523 current_class_type current_function_decl
530 Those last two make life interesting. If we're in a function which is
531 itself inside a class, we need decls to go into the fn's decls (our
532 second case below). But if we're in a class and the class itself is
533 inside a function, we need decls to go into the decls for the class. To
534 achieve this last goal, we must see if, when both current_class_ptr and
535 current_function_decl are set, the class was declared inside that
536 function. If so, we know to put the decls into the class's scope. */
541 if (current_function_decl == NULL_TREE)
542 return current_class_type;
543 if (current_class_type == NULL_TREE)
544 return current_function_decl;
545 if ((DECL_FUNCTION_MEMBER_P (current_function_decl)
546 && same_type_p (DECL_CONTEXT (current_function_decl),
548 || (DECL_FRIEND_CONTEXT (current_function_decl)
549 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl),
550 current_class_type)))
551 return current_function_decl;
553 return current_class_type;
556 /* Returns nonzero if we are currently in a function scope. Note
557 that this function returns zero if we are within a local class, but
558 not within a member function body of the local class. */
561 at_function_scope_p ()
563 tree cs = current_scope ();
564 return cs && TREE_CODE (cs) == FUNCTION_DECL;
567 /* Returns true if the innermost active scope is a class scope. */
572 tree cs = current_scope ();
573 return cs && TYPE_P (cs);
576 /* Return the scope of DECL, as appropriate when doing name-lookup. */
579 context_for_name_lookup (tree decl)
583 For the purposes of name lookup, after the anonymous union
584 definition, the members of the anonymous union are considered to
585 have been defined in the scope in which the anonymous union is
587 tree context = DECL_CONTEXT (decl);
589 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context))
590 context = TYPE_CONTEXT (context);
592 context = global_namespace;
597 /* The accessibility routines use BINFO_ACCESS for scratch space
598 during the computation of the accssibility of some declaration. */
600 #define BINFO_ACCESS(NODE) \
601 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
603 /* Set the access associated with NODE to ACCESS. */
605 #define SET_BINFO_ACCESS(NODE, ACCESS) \
606 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
607 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
609 /* Called from access_in_type via dfs_walk. Calculate the access to
610 DATA (which is really a DECL) in BINFO. */
613 dfs_access_in_type (tree binfo, void *data)
615 tree decl = (tree) data;
616 tree type = BINFO_TYPE (binfo);
617 access_kind access = ak_none;
619 if (context_for_name_lookup (decl) == type)
621 /* If we have desceneded to the scope of DECL, just note the
622 appropriate access. */
623 if (TREE_PRIVATE (decl))
625 else if (TREE_PROTECTED (decl))
626 access = ak_protected;
632 /* First, check for an access-declaration that gives us more
633 access to the DECL. The CONST_DECL for an enumeration
634 constant will not have DECL_LANG_SPECIFIC, and thus no
636 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl))
638 tree decl_access = purpose_member (type, DECL_ACCESS (decl));
642 decl_access = TREE_VALUE (decl_access);
644 if (decl_access == access_public_node)
646 else if (decl_access == access_protected_node)
647 access = ak_protected;
648 else if (decl_access == access_private_node)
651 my_friendly_assert (false, 20030217);
659 tree binfos, accesses;
661 /* Otherwise, scan our baseclasses, and pick the most favorable
663 binfos = BINFO_BASETYPES (binfo);
664 accesses = BINFO_BASEACCESSES (binfo);
665 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
666 for (i = 0; i < n_baselinks; ++i)
668 tree base_binfo = TREE_VEC_ELT (binfos, i);
669 tree base_access = TREE_VEC_ELT (accesses, i);
670 access_kind base_access_now = BINFO_ACCESS (base_binfo);
672 if (base_access_now == ak_none || base_access_now == ak_private)
673 /* If it was not accessible in the base, or only
674 accessible as a private member, we can't access it
676 base_access_now = ak_none;
677 else if (base_access == access_protected_node)
678 /* Public and protected members in the base become
680 base_access_now = ak_protected;
681 else if (base_access == access_private_node)
682 /* Public and protected members in the base become
684 base_access_now = ak_private;
686 /* See if the new access, via this base, gives more
687 access than our previous best access. */
688 if (base_access_now != ak_none
689 && (access == ak_none || base_access_now < access))
691 access = base_access_now;
693 /* If the new access is public, we can't do better. */
694 if (access == ak_public)
701 /* Note the access to DECL in TYPE. */
702 SET_BINFO_ACCESS (binfo, access);
704 /* Mark TYPE as visited so that if we reach it again we do not
705 duplicate our efforts here. */
706 BINFO_MARKED (binfo) = 1;
711 /* Return the access to DECL in TYPE. */
714 access_in_type (tree type, tree decl)
716 tree binfo = TYPE_BINFO (type);
718 /* We must take into account
722 If a name can be reached by several paths through a multiple
723 inheritance graph, the access is that of the path that gives
726 The algorithm we use is to make a post-order depth-first traversal
727 of the base-class hierarchy. As we come up the tree, we annotate
728 each node with the most lenient access. */
729 dfs_walk_real (binfo, 0, dfs_access_in_type, unmarkedp, decl);
730 dfs_walk (binfo, dfs_unmark, markedp, 0);
732 return BINFO_ACCESS (binfo);
735 /* Called from dfs_accessible_p via dfs_walk. */
738 dfs_accessible_queue_p (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
740 tree binfo = BINFO_BASETYPE (derived, ix);
742 if (BINFO_MARKED (binfo))
745 /* If this class is inherited via private or protected inheritance,
746 then we can't see it, unless we are a friend of the derived class. */
747 if (BINFO_BASEACCESS (derived, ix) != access_public_node
748 && !is_friend (BINFO_TYPE (derived), current_scope ()))
754 /* Called from dfs_accessible_p via dfs_walk. */
757 dfs_accessible_p (tree binfo, void *data)
759 int protected_ok = data != 0;
762 BINFO_MARKED (binfo) = 1;
763 access = BINFO_ACCESS (binfo);
764 if (access == ak_public || (access == ak_protected && protected_ok))
766 else if (access != ak_none
767 && is_friend (BINFO_TYPE (binfo), current_scope ()))
773 /* Returns nonzero if it is OK to access DECL through an object
774 indiated by BINFO in the context of DERIVED. */
777 protected_accessible_p (tree decl, tree derived, tree binfo)
781 /* We're checking this clause from [class.access.base]
783 m as a member of N is protected, and the reference occurs in a
784 member or friend of class N, or in a member or friend of a
785 class P derived from N, where m as a member of P is private or
788 Here DERIVED is a possible P and DECL is m. accessible_p will
789 iterate over various values of N, but the access to m in DERIVED
792 Note that I believe that the passage above is wrong, and should read
793 "...is private or protected or public"; otherwise you get bizarre results
794 whereby a public using-decl can prevent you from accessing a protected
795 member of a base. (jason 2000/02/28) */
797 /* If DERIVED isn't derived from m's class, then it can't be a P. */
798 if (!DERIVED_FROM_P (context_for_name_lookup (decl), derived))
801 access = access_in_type (derived, decl);
803 /* If m is inaccessible in DERIVED, then it's not a P. */
804 if (access == ak_none)
809 When a friend or a member function of a derived class references
810 a protected nonstatic member of a base class, an access check
811 applies in addition to those described earlier in clause
812 _class.access_) Except when forming a pointer to member
813 (_expr.unary.op_), the access must be through a pointer to,
814 reference to, or object of the derived class itself (or any class
815 derived from that class) (_expr.ref_). If the access is to form
816 a pointer to member, the nested-name-specifier shall name the
817 derived class (or any class derived from that class). */
818 if (DECL_NONSTATIC_MEMBER_P (decl))
820 /* We can tell through what the reference is occurring by
821 chasing BINFO up to the root. */
823 while (BINFO_INHERITANCE_CHAIN (t))
824 t = BINFO_INHERITANCE_CHAIN (t);
826 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t)))
833 /* Returns nonzero if SCOPE is a friend of a type which would be able
834 to access DECL through the object indicated by BINFO. */
837 friend_accessible_p (tree scope, tree decl, tree binfo)
839 tree befriending_classes;
845 if (TREE_CODE (scope) == FUNCTION_DECL
846 || DECL_FUNCTION_TEMPLATE_P (scope))
847 befriending_classes = DECL_BEFRIENDING_CLASSES (scope);
848 else if (TYPE_P (scope))
849 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope);
853 for (t = befriending_classes; t; t = TREE_CHAIN (t))
854 if (protected_accessible_p (decl, TREE_VALUE (t), binfo))
857 /* Nested classes are implicitly friends of their enclosing types, as
858 per core issue 45 (this is a change from the standard). */
860 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t))
861 if (protected_accessible_p (decl, t, binfo))
864 if (TREE_CODE (scope) == FUNCTION_DECL
865 || DECL_FUNCTION_TEMPLATE_P (scope))
867 /* Perhaps this SCOPE is a member of a class which is a
869 if (DECL_CLASS_SCOPE_P (decl)
870 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo))
873 /* Or an instantiation of something which is a friend. */
874 if (DECL_TEMPLATE_INFO (scope))
875 return friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo);
877 else if (CLASSTYPE_TEMPLATE_INFO (scope))
878 return friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope), decl, binfo);
883 /* DECL is a declaration from a base class of TYPE, which was the
884 class used to name DECL. Return nonzero if, in the current
885 context, DECL is accessible. If TYPE is actually a BINFO node,
886 then we can tell in what context the access is occurring by looking
887 at the most derived class along the path indicated by BINFO. */
890 accessible_p (tree type, tree decl)
895 /* Nonzero if it's OK to access DECL if it has protected
896 accessibility in TYPE. */
897 int protected_ok = 0;
899 /* If we're not checking access, everything is accessible. */
900 if (!scope_chain->check_access)
903 /* If this declaration is in a block or namespace scope, there's no
905 if (!TYPE_P (context_for_name_lookup (decl)))
911 type = BINFO_TYPE (type);
914 binfo = TYPE_BINFO (type);
916 /* [class.access.base]
918 A member m is accessible when named in class N if
920 --m as a member of N is public, or
922 --m as a member of N is private, and the reference occurs in a
923 member or friend of class N, or
925 --m as a member of N is protected, and the reference occurs in a
926 member or friend of class N, or in a member or friend of a
927 class P derived from N, where m as a member of P is private or
930 --there exists a base class B of N that is accessible at the point
931 of reference, and m is accessible when named in class B.
933 We walk the base class hierarchy, checking these conditions. */
935 /* Figure out where the reference is occurring. Check to see if
936 DECL is private or protected in this scope, since that will
937 determine whether protected access is allowed. */
938 if (current_class_type)
939 protected_ok = protected_accessible_p (decl, current_class_type, binfo);
941 /* Now, loop through the classes of which we are a friend. */
943 protected_ok = friend_accessible_p (current_scope (), decl, binfo);
945 /* Standardize the binfo that access_in_type will use. We don't
946 need to know what path was chosen from this point onwards. */
947 binfo = TYPE_BINFO (type);
949 /* Compute the accessibility of DECL in the class hierarchy
950 dominated by type. */
951 access_in_type (type, decl);
952 /* Walk the hierarchy again, looking for a base class that allows
954 t = dfs_walk (binfo, dfs_accessible_p,
955 dfs_accessible_queue_p,
956 protected_ok ? &protected_ok : 0);
957 /* Clear any mark bits. Note that we have to walk the whole tree
958 here, since we have aborted the previous walk from some point
960 dfs_walk (binfo, dfs_unmark, 0, 0);
962 return t != NULL_TREE;
965 struct lookup_field_info {
966 /* The type in which we're looking. */
968 /* The name of the field for which we're looking. */
970 /* If non-NULL, the current result of the lookup. */
972 /* The path to RVAL. */
974 /* If non-NULL, the lookup was ambiguous, and this is a list of the
977 /* If nonzero, we are looking for types, not data members. */
979 /* If something went wrong, a message indicating what. */
983 /* Returns nonzero if BINFO is not hidden by the value found by the
984 lookup so far. If BINFO is hidden, then there's no need to look in
985 it. DATA is really a struct lookup_field_info. Called from
986 lookup_field via breadth_first_search. */
989 lookup_field_queue_p (tree derived, int ix, void *data)
991 tree binfo = BINFO_BASETYPE (derived, ix);
992 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
994 /* Don't look for constructors or destructors in base classes. */
995 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
998 /* If this base class is hidden by the best-known value so far, we
999 don't need to look. */
1000 if (lfi->rval_binfo && original_binfo (binfo, lfi->rval_binfo))
1003 /* If this is a dependent base, don't look in it. */
1004 if (BINFO_DEPENDENT_BASE_P (binfo))
1010 /* Within the scope of a template class, you can refer to the to the
1011 current specialization with the name of the template itself. For
1014 template <typename T> struct S { S* sp; }
1016 Returns nonzero if DECL is such a declaration in a class TYPE. */
1019 template_self_reference_p (tree type, tree decl)
1021 return (CLASSTYPE_USE_TEMPLATE (type)
1022 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
1023 && TREE_CODE (decl) == TYPE_DECL
1024 && DECL_ARTIFICIAL (decl)
1025 && DECL_NAME (decl) == constructor_name (type));
1029 /* Nonzero for a class member means that it is shared between all objects
1032 [class.member.lookup]:If the resulting set of declarations are not all
1033 from sub-objects of the same type, or the set has a nonstatic member
1034 and includes members from distinct sub-objects, there is an ambiguity
1035 and the program is ill-formed.
1037 This function checks that T contains no nonstatic members. */
1040 shared_member_p (tree t)
1042 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \
1043 || TREE_CODE (t) == CONST_DECL)
1045 if (is_overloaded_fn (t))
1047 for (; t; t = OVL_NEXT (t))
1049 tree fn = OVL_CURRENT (t);
1050 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
1058 /* DATA is really a struct lookup_field_info. Look for a field with
1059 the name indicated there in BINFO. If this function returns a
1060 non-NULL value it is the result of the lookup. Called from
1061 lookup_field via breadth_first_search. */
1064 lookup_field_r (tree binfo, void *data)
1066 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1067 tree type = BINFO_TYPE (binfo);
1068 tree nval = NULL_TREE;
1070 /* First, look for a function. There can't be a function and a data
1071 member with the same name, and if there's a function and a type
1072 with the same name, the type is hidden by the function. */
1073 if (!lfi->want_type)
1075 int idx = lookup_fnfields_1 (type, lfi->name);
1077 nval = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), idx);
1081 /* Look for a data member or type. */
1082 nval = lookup_field_1 (type, lfi->name);
1084 /* If there is no declaration with the indicated name in this type,
1085 then there's nothing to do. */
1089 /* If we're looking up a type (as with an elaborated type specifier)
1090 we ignore all non-types we find. */
1091 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL
1092 && !DECL_CLASS_TEMPLATE_P (nval))
1094 if (lfi->name == TYPE_IDENTIFIER (type))
1096 /* If the aggregate has no user defined constructors, we allow
1097 it to have fields with the same name as the enclosing type.
1098 If we are looking for that name, find the corresponding
1100 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval))
1101 if (DECL_NAME (nval) == lfi->name
1102 && TREE_CODE (nval) == TYPE_DECL)
1109 nval = purpose_member (lfi->name, CLASSTYPE_TAGS (type));
1111 nval = TYPE_MAIN_DECL (TREE_VALUE (nval));
1117 /* You must name a template base class with a template-id. */
1118 if (!same_type_p (type, lfi->type)
1119 && template_self_reference_p (type, nval))
1122 /* If the lookup already found a match, and the new value doesn't
1123 hide the old one, we might have an ambiguity. */
1124 if (lfi->rval_binfo && !original_binfo (lfi->rval_binfo, binfo))
1126 if (nval == lfi->rval && shared_member_p (nval))
1127 /* The two things are really the same. */
1129 else if (original_binfo (binfo, lfi->rval_binfo))
1130 /* The previous value hides the new one. */
1134 /* We have a real ambiguity. We keep a chain of all the
1136 if (!lfi->ambiguous && lfi->rval)
1138 /* This is the first time we noticed an ambiguity. Add
1139 what we previously thought was a reasonable candidate
1141 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE);
1142 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1145 /* Add the new value. */
1146 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous);
1147 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1148 lfi->errstr = "request for member `%D' is ambiguous";
1154 lfi->rval_binfo = binfo;
1160 /* Return a "baselink" which BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1161 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1162 FUNCTIONS, and OPTYPE respectively. */
1165 build_baselink (tree binfo, tree access_binfo, tree functions, tree optype)
1169 my_friendly_assert (TREE_CODE (functions) == FUNCTION_DECL
1170 || TREE_CODE (functions) == TEMPLATE_DECL
1171 || TREE_CODE (functions) == TEMPLATE_ID_EXPR
1172 || TREE_CODE (functions) == OVERLOAD,
1174 my_friendly_assert (!optype || TYPE_P (optype), 20020730);
1175 my_friendly_assert (TREE_TYPE (functions), 20020805);
1177 baselink = make_node (BASELINK);
1178 TREE_TYPE (baselink) = TREE_TYPE (functions);
1179 BASELINK_BINFO (baselink) = binfo;
1180 BASELINK_ACCESS_BINFO (baselink) = access_binfo;
1181 BASELINK_FUNCTIONS (baselink) = functions;
1182 BASELINK_OPTYPE (baselink) = optype;
1187 /* Look for a member named NAME in an inheritance lattice dominated by
1188 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1189 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1190 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1191 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1192 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1193 TREE_VALUEs are the list of ambiguous candidates.
1195 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1197 If nothing can be found return NULL_TREE and do not issue an error. */
1200 lookup_member (tree xbasetype, tree name, int protect, bool want_type)
1202 tree rval, rval_binfo = NULL_TREE;
1203 tree type = NULL_TREE, basetype_path = NULL_TREE;
1204 struct lookup_field_info lfi;
1206 /* rval_binfo is the binfo associated with the found member, note,
1207 this can be set with useful information, even when rval is not
1208 set, because it must deal with ALL members, not just non-function
1209 members. It is used for ambiguity checking and the hidden
1210 checks. Whereas rval is only set if a proper (not hidden)
1211 non-function member is found. */
1213 const char *errstr = 0;
1216 if (TREE_CODE (name) != IDENTIFIER_NODE)
1219 if (xbasetype == current_class_type && TYPE_BEING_DEFINED (xbasetype)
1220 && IDENTIFIER_CLASS_VALUE (name))
1222 tree field = IDENTIFIER_CLASS_VALUE (name);
1223 if (! is_overloaded_fn (field)
1224 && ! (want_type && TREE_CODE (field) != TYPE_DECL))
1225 /* We're in the scope of this class, and the value has already
1226 been looked up. Just return the cached value. */
1230 if (TREE_CODE (xbasetype) == TREE_VEC)
1232 type = BINFO_TYPE (xbasetype);
1233 basetype_path = xbasetype;
1235 else if (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype)))
1238 basetype_path = TYPE_BINFO (type);
1239 my_friendly_assert (BINFO_INHERITANCE_CHAIN (basetype_path) == NULL_TREE,
1245 complete_type (type);
1247 #ifdef GATHER_STATISTICS
1248 n_calls_lookup_field++;
1249 #endif /* GATHER_STATISTICS */
1251 memset ((PTR) &lfi, 0, sizeof (lfi));
1254 lfi.want_type = want_type;
1255 bfs_walk (basetype_path, &lookup_field_r, &lookup_field_queue_p, &lfi);
1257 rval_binfo = lfi.rval_binfo;
1259 type = BINFO_TYPE (rval_binfo);
1260 errstr = lfi.errstr;
1262 /* If we are not interested in ambiguities, don't report them;
1263 just return NULL_TREE. */
1264 if (!protect && lfi.ambiguous)
1270 return lfi.ambiguous;
1277 In the case of overloaded function names, access control is
1278 applied to the function selected by overloaded resolution. */
1279 if (rval && protect && !is_overloaded_fn (rval)
1280 && !enforce_access (xbasetype, rval))
1281 return error_mark_node;
1283 if (errstr && protect)
1285 error (errstr, name, type);
1287 print_candidates (lfi.ambiguous);
1288 rval = error_mark_node;
1291 if (rval && is_overloaded_fn (rval))
1292 rval = build_baselink (rval_binfo, basetype_path, rval,
1293 (IDENTIFIER_TYPENAME_P (name)
1294 ? TREE_TYPE (name): NULL_TREE));
1298 /* Like lookup_member, except that if we find a function member we
1299 return NULL_TREE. */
1302 lookup_field (tree xbasetype, tree name, int protect, bool want_type)
1304 tree rval = lookup_member (xbasetype, name, protect, want_type);
1306 /* Ignore functions. */
1307 if (rval && BASELINK_P (rval))
1313 /* Like lookup_member, except that if we find a non-function member we
1314 return NULL_TREE. */
1317 lookup_fnfields (tree xbasetype, tree name, int protect)
1319 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/false);
1321 /* Ignore non-functions. */
1322 if (rval && !BASELINK_P (rval))
1328 /* TYPE is a class type. Return the index of the fields within
1329 the method vector with name NAME, or -1 is no such field exists. */
1332 lookup_fnfields_1 (tree type, tree name)
1334 tree method_vec = (CLASS_TYPE_P (type)
1335 ? CLASSTYPE_METHOD_VEC (type)
1338 if (method_vec != 0)
1341 register tree *methods = &TREE_VEC_ELT (method_vec, 0);
1342 int len = TREE_VEC_LENGTH (method_vec);
1345 #ifdef GATHER_STATISTICS
1346 n_calls_lookup_fnfields_1++;
1347 #endif /* GATHER_STATISTICS */
1349 /* Constructors are first... */
1350 if (name == ctor_identifier)
1351 return (methods[CLASSTYPE_CONSTRUCTOR_SLOT]
1352 ? CLASSTYPE_CONSTRUCTOR_SLOT : -1);
1353 /* and destructors are second. */
1354 if (name == dtor_identifier)
1355 return (methods[CLASSTYPE_DESTRUCTOR_SLOT]
1356 ? CLASSTYPE_DESTRUCTOR_SLOT : -1);
1358 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1359 i < len && methods[i];
1362 #ifdef GATHER_STATISTICS
1363 n_outer_fields_searched++;
1364 #endif /* GATHER_STATISTICS */
1366 tmp = OVL_CURRENT (methods[i]);
1367 if (DECL_NAME (tmp) == name)
1370 /* If the type is complete and we're past the conversion ops,
1371 switch to binary search. */
1372 if (! DECL_CONV_FN_P (tmp)
1373 && COMPLETE_TYPE_P (type))
1375 int lo = i + 1, hi = len;
1381 #ifdef GATHER_STATISTICS
1382 n_outer_fields_searched++;
1383 #endif /* GATHER_STATISTICS */
1385 tmp = DECL_NAME (OVL_CURRENT (methods[i]));
1389 else if (tmp < name)
1398 /* If we didn't find it, it might have been a template
1399 conversion operator to a templated type. If there are any,
1400 such template conversion operators will all be overloaded on
1401 the first conversion slot. (Note that we don't look for this
1402 case above so that we will always find specializations
1404 if (IDENTIFIER_TYPENAME_P (name))
1406 i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1407 if (i < len && methods[i])
1409 tmp = OVL_CURRENT (methods[i]);
1410 if (TREE_CODE (tmp) == TEMPLATE_DECL
1411 && DECL_TEMPLATE_CONV_FN_P (tmp))
1420 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1421 the class or namespace used to qualify the name. CONTEXT_CLASS is
1422 the class corresponding to the object in which DECL will be used.
1423 Return a possibly modified version of DECL that takes into account
1426 In particular, consider an expression like `B::m' in the context of
1427 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1428 then the most derived class indicated by the BASELINK_BINFO will be
1429 `B', not `D'. This function makes that adjustment. */
1432 adjust_result_of_qualified_name_lookup (tree decl,
1433 tree qualifying_scope,
1436 if (context_class && CLASS_TYPE_P (qualifying_scope)
1437 && DERIVED_FROM_P (qualifying_scope, context_class)
1438 && BASELINK_P (decl))
1442 my_friendly_assert (CLASS_TYPE_P (context_class), 20020808);
1444 /* Look for the QUALIFYING_SCOPE as a base of the
1445 CONTEXT_CLASS. If QUALIFYING_SCOPE is ambiguous, we cannot
1446 be sure yet than an error has occurred; perhaps the function
1447 chosen by overload resolution will be static. */
1448 base = lookup_base (context_class, qualifying_scope,
1449 ba_ignore | ba_quiet, NULL);
1452 BASELINK_ACCESS_BINFO (decl) = base;
1453 BASELINK_BINFO (decl)
1454 = lookup_base (base, BINFO_TYPE (BASELINK_BINFO (decl)),
1455 ba_ignore | ba_quiet,
1464 /* Walk the class hierarchy dominated by TYPE. FN is called for each
1465 type in the hierarchy, in a breadth-first preorder traversal.
1466 If it ever returns a non-NULL value, that value is immediately
1467 returned and the walk is terminated. At each node, FN is passed a
1468 BINFO indicating the path from the curently visited base-class to
1469 TYPE. Before each base-class is walked QFN is called. If the
1470 value returned is nonzero, the base-class is walked; otherwise it
1471 is not. If QFN is NULL, it is treated as a function which always
1472 returns 1. Both FN and QFN are passed the DATA whenever they are
1475 Implementation notes: Uses a circular queue, which starts off on
1476 the stack but gets moved to the malloc arena if it needs to be
1477 enlarged. The underflow and overflow conditions are
1478 indistinguishable except by context: if head == tail and we just
1479 moved the head pointer, the queue is empty, but if we just moved
1480 the tail pointer, the queue is full.
1481 Start with enough room for ten concurrent base classes. That
1482 will be enough for most hierarchies. */
1483 #define BFS_WALK_INITIAL_QUEUE_SIZE 10
1486 bfs_walk (tree binfo,
1487 tree (*fn) (tree, void *),
1488 tree (*qfn) (tree, int, void *),
1491 tree rval = NULL_TREE;
1493 tree bases_initial[BFS_WALK_INITIAL_QUEUE_SIZE];
1494 /* A circular queue of the base classes of BINFO. These will be
1495 built up in breadth-first order, except where QFN prunes the
1498 size_t base_buffer_size = BFS_WALK_INITIAL_QUEUE_SIZE;
1499 tree *base_buffer = bases_initial;
1502 base_buffer[tail++] = binfo;
1504 while (head != tail)
1507 tree binfo = base_buffer[head++];
1508 if (head == base_buffer_size)
1511 /* Is this the one we're looking for? If so, we're done. */
1512 rval = fn (binfo, data);
1516 n_bases = BINFO_N_BASETYPES (binfo);
1517 for (ix = 0; ix != n_bases; ix++)
1522 base_binfo = (*qfn) (binfo, ix, data);
1524 base_binfo = BINFO_BASETYPE (binfo, ix);
1528 base_buffer[tail++] = base_binfo;
1529 if (tail == base_buffer_size)
1533 tree *new_buffer = xmalloc (2 * base_buffer_size
1535 memcpy (&new_buffer[0], &base_buffer[0],
1536 tail * sizeof (tree));
1537 memcpy (&new_buffer[head + base_buffer_size],
1539 (base_buffer_size - head) * sizeof (tree));
1540 if (base_buffer_size != BFS_WALK_INITIAL_QUEUE_SIZE)
1542 base_buffer = new_buffer;
1543 head += base_buffer_size;
1544 base_buffer_size *= 2;
1551 if (base_buffer_size != BFS_WALK_INITIAL_QUEUE_SIZE)
1556 /* Exactly like bfs_walk, except that a depth-first traversal is
1557 performed, and PREFN is called in preorder, while POSTFN is called
1561 dfs_walk_real (tree binfo,
1562 tree (*prefn) (tree, void *),
1563 tree (*postfn) (tree, void *),
1564 tree (*qfn) (tree, int, void *),
1567 tree rval = NULL_TREE;
1569 /* Call the pre-order walking function. */
1572 rval = (*prefn) (binfo, data);
1577 /* Process the basetypes. */
1578 if (BINFO_BASETYPES (binfo))
1580 int i, n = TREE_VEC_LENGTH (BINFO_BASETYPES (binfo));
1581 for (i = 0; i != n; i++)
1586 base_binfo = (*qfn) (binfo, i, data);
1588 base_binfo = BINFO_BASETYPE (binfo, i);
1592 rval = dfs_walk_real (base_binfo, prefn, postfn, qfn, data);
1599 /* Call the post-order walking function. */
1601 rval = (*postfn) (binfo, data);
1606 /* Exactly like bfs_walk, except that a depth-first post-order traversal is
1610 dfs_walk (tree binfo,
1611 tree (*fn) (tree, void *),
1612 tree (*qfn) (tree, int, void *),
1615 return dfs_walk_real (binfo, 0, fn, qfn, data);
1618 /* Check that virtual overrider OVERRIDER is acceptable for base function
1619 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1622 check_final_overrider (tree overrider, tree basefn)
1624 tree over_type = TREE_TYPE (overrider);
1625 tree base_type = TREE_TYPE (basefn);
1626 tree over_return = TREE_TYPE (over_type);
1627 tree base_return = TREE_TYPE (base_type);
1628 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type);
1629 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type);
1632 if (same_type_p (base_return, over_return))
1634 else if ((CLASS_TYPE_P (over_return) && CLASS_TYPE_P (base_return))
1635 || (TREE_CODE (base_return) == TREE_CODE (over_return)
1636 && POINTER_TYPE_P (base_return)))
1638 /* Potentially covariant. */
1639 unsigned base_quals, over_quals;
1641 fail = !POINTER_TYPE_P (base_return);
1644 fail = cp_type_quals (base_return) != cp_type_quals (over_return);
1646 base_return = TREE_TYPE (base_return);
1647 over_return = TREE_TYPE (over_return);
1649 base_quals = cp_type_quals (base_return);
1650 over_quals = cp_type_quals (over_return);
1652 if ((base_quals & over_quals) != over_quals)
1655 if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return))
1657 tree binfo = lookup_base (over_return, base_return,
1658 ba_check | ba_quiet, NULL);
1664 && can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type)))
1665 /* GNU extension, allow trivial pointer conversions such as
1666 converting to void *, or qualification conversion. */
1668 /* can_convert will permit user defined conversion from a
1669 (reference to) class type. We must reject them. */
1670 over_return = TREE_TYPE (over_type);
1671 if (TREE_CODE (over_return) == REFERENCE_TYPE)
1672 over_return = TREE_TYPE (over_return);
1673 if (CLASS_TYPE_P (over_return))
1683 else if (IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider)))
1689 cp_error_at ("invalid covariant return type for `%#D'", overrider);
1690 cp_error_at (" overriding `%#D'", basefn);
1694 cp_error_at ("conflicting return type specified for `%#D'",
1696 cp_error_at (" overriding `%#D'", basefn);
1698 SET_IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider),
1699 DECL_CONTEXT (overrider));
1703 /* Check throw specifier is at least as strict. */
1704 if (!comp_except_specs (base_throw, over_throw, 0))
1706 if (!IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider)))
1708 cp_error_at ("looser throw specifier for `%#F'", overrider);
1709 cp_error_at (" overriding `%#F'", basefn);
1710 SET_IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider),
1711 DECL_CONTEXT (overrider));
1719 /* Given a class TYPE, and a function decl FNDECL, look for
1720 virtual functions in TYPE's hierarchy which FNDECL overrides.
1721 We do not look in TYPE itself, only its bases.
1723 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1724 find that it overrides anything.
1726 We check that every function which is overridden, is correctly
1730 look_for_overrides (tree type, tree fndecl)
1732 tree binfo = TYPE_BINFO (type);
1733 tree basebinfos = BINFO_BASETYPES (binfo);
1734 int nbasebinfos = basebinfos ? TREE_VEC_LENGTH (basebinfos) : 0;
1738 for (ix = 0; ix != nbasebinfos; ix++)
1740 tree basetype = BINFO_TYPE (TREE_VEC_ELT (basebinfos, ix));
1742 if (TYPE_POLYMORPHIC_P (basetype))
1743 found += look_for_overrides_r (basetype, fndecl);
1748 /* Look in TYPE for virtual functions with the same signature as
1752 look_for_overrides_here (tree type, tree fndecl)
1756 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl))
1757 ix = CLASSTYPE_DESTRUCTOR_SLOT;
1759 ix = lookup_fnfields_1 (type, DECL_NAME (fndecl));
1762 tree fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), ix);
1764 for (; fns; fns = OVL_NEXT (fns))
1766 tree fn = OVL_CURRENT (fns);
1768 if (!DECL_VIRTUAL_P (fn))
1769 /* Not a virtual. */;
1770 else if (DECL_CONTEXT (fn) != type)
1771 /* Introduced with a using declaration. */;
1772 else if (DECL_STATIC_FUNCTION_P (fndecl))
1774 tree btypes = TYPE_ARG_TYPES (TREE_TYPE (fn));
1775 tree dtypes = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1776 if (compparms (TREE_CHAIN (btypes), dtypes))
1779 else if (same_signature_p (fndecl, fn))
1786 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1787 TYPE itself and its bases. */
1790 look_for_overrides_r (tree type, tree fndecl)
1792 tree fn = look_for_overrides_here (type, fndecl);
1795 if (DECL_STATIC_FUNCTION_P (fndecl))
1797 /* A static member function cannot match an inherited
1798 virtual member function. */
1799 cp_error_at ("`%#D' cannot be declared", fndecl);
1800 cp_error_at (" since `%#D' declared in base class", fn);
1804 /* It's definitely virtual, even if not explicitly set. */
1805 DECL_VIRTUAL_P (fndecl) = 1;
1806 check_final_overrider (fndecl, fn);
1811 /* We failed to find one declared in this class. Look in its bases. */
1812 return look_for_overrides (type, fndecl);
1815 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1818 dfs_get_pure_virtuals (tree binfo, void *data)
1820 tree type = (tree) data;
1822 /* We're not interested in primary base classes; the derived class
1823 of which they are a primary base will contain the information we
1825 if (!BINFO_PRIMARY_P (binfo))
1829 for (virtuals = BINFO_VIRTUALS (binfo);
1831 virtuals = TREE_CHAIN (virtuals))
1832 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals)))
1833 CLASSTYPE_PURE_VIRTUALS (type)
1834 = tree_cons (NULL_TREE, BV_FN (virtuals),
1835 CLASSTYPE_PURE_VIRTUALS (type));
1838 BINFO_MARKED (binfo) = 1;
1843 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1846 get_pure_virtuals (tree type)
1850 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1851 is going to be overridden. */
1852 CLASSTYPE_PURE_VIRTUALS (type) = NULL_TREE;
1853 /* Now, run through all the bases which are not primary bases, and
1854 collect the pure virtual functions. We look at the vtable in
1855 each class to determine what pure virtual functions are present.
1856 (A primary base is not interesting because the derived class of
1857 which it is a primary base will contain vtable entries for the
1858 pure virtuals in the base class. */
1859 dfs_walk (TYPE_BINFO (type), dfs_get_pure_virtuals, unmarkedp, type);
1860 dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, type);
1862 /* Put the pure virtuals in dfs order. */
1863 CLASSTYPE_PURE_VIRTUALS (type) = nreverse (CLASSTYPE_PURE_VIRTUALS (type));
1865 for (vbases = CLASSTYPE_VBASECLASSES (type);
1867 vbases = TREE_CHAIN (vbases))
1871 for (virtuals = BINFO_VIRTUALS (TREE_VALUE (vbases));
1873 virtuals = TREE_CHAIN (virtuals))
1875 tree base_fndecl = BV_FN (virtuals);
1876 if (DECL_NEEDS_FINAL_OVERRIDER_P (base_fndecl))
1877 error ("`%#D' needs a final overrider", base_fndecl);
1882 /* DEPTH-FIRST SEARCH ROUTINES. */
1885 markedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
1887 tree binfo = BINFO_BASETYPE (derived, ix);
1889 return BINFO_MARKED (binfo) ? binfo : NULL_TREE;
1893 unmarkedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
1895 tree binfo = BINFO_BASETYPE (derived, ix);
1897 return !BINFO_MARKED (binfo) ? binfo : NULL_TREE;
1901 marked_pushdecls_p (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
1903 tree binfo = BINFO_BASETYPE (derived, ix);
1905 return (!BINFO_DEPENDENT_BASE_P (binfo)
1906 && BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
1910 unmarked_pushdecls_p (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
1912 tree binfo = BINFO_BASETYPE (derived, ix);
1914 return (!BINFO_DEPENDENT_BASE_P (binfo)
1915 && !BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
1918 /* The worker functions for `dfs_walk'. These do not need to
1919 test anything (vis a vis marking) if they are paired with
1920 a predicate function (above). */
1923 dfs_unmark (tree binfo, void *data ATTRIBUTE_UNUSED)
1925 BINFO_MARKED (binfo) = 0;
1930 /* Debug info for C++ classes can get very large; try to avoid
1931 emitting it everywhere.
1933 Note that this optimization wins even when the target supports
1934 BINCL (if only slightly), and reduces the amount of work for the
1938 maybe_suppress_debug_info (tree t)
1940 /* We can't do the usual TYPE_DECL_SUPPRESS_DEBUG thing with DWARF, which
1941 does not support name references between translation units. It supports
1942 symbolic references between translation units, but only within a single
1943 executable or shared library.
1945 For DWARF 2, we handle TYPE_DECL_SUPPRESS_DEBUG by pretending
1946 that the type was never defined, so we only get the members we
1948 if (write_symbols == DWARF_DEBUG || write_symbols == NO_DEBUG)
1951 /* We might have set this earlier in cp_finish_decl. */
1952 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 0;
1954 /* If we already know how we're handling this class, handle debug info
1956 if (CLASSTYPE_INTERFACE_KNOWN (t))
1958 if (CLASSTYPE_INTERFACE_ONLY (t))
1959 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
1960 /* else don't set it. */
1962 /* If the class has a vtable, write out the debug info along with
1964 else if (TYPE_CONTAINS_VPTR_P (t))
1965 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
1967 /* Otherwise, just emit the debug info normally. */
1970 /* Note that we want debugging information for a base class of a class
1971 whose vtable is being emitted. Normally, this would happen because
1972 calling the constructor for a derived class implies calling the
1973 constructors for all bases, which involve initializing the
1974 appropriate vptr with the vtable for the base class; but in the
1975 presence of optimization, this initialization may be optimized
1976 away, so we tell finish_vtable_vardecl that we want the debugging
1977 information anyway. */
1980 dfs_debug_mark (tree binfo, void *data ATTRIBUTE_UNUSED)
1982 tree t = BINFO_TYPE (binfo);
1984 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
1989 /* Returns BINFO if we haven't already noted that we want debugging
1990 info for this base class. */
1993 dfs_debug_unmarkedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
1995 tree binfo = BINFO_BASETYPE (derived, ix);
1997 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo))
1998 ? binfo : NULL_TREE);
2001 /* Write out the debugging information for TYPE, whose vtable is being
2002 emitted. Also walk through our bases and note that we want to
2003 write out information for them. This avoids the problem of not
2004 writing any debug info for intermediate basetypes whose
2005 constructors, and thus the references to their vtables, and thus
2006 the vtables themselves, were optimized away. */
2009 note_debug_info_needed (tree type)
2011 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)))
2013 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)) = 0;
2014 rest_of_type_compilation (type, toplevel_bindings_p ());
2017 dfs_walk (TYPE_BINFO (type), dfs_debug_mark, dfs_debug_unmarkedp, 0);
2020 /* Subroutines of push_class_decls (). */
2023 setup_class_bindings (tree name, int type_binding_p)
2025 tree type_binding = NULL_TREE;
2028 /* If we've already done the lookup for this declaration, we're
2030 if (IDENTIFIER_CLASS_VALUE (name))
2033 /* First, deal with the type binding. */
2036 type_binding = lookup_member (current_class_type, name,
2037 /*protect=*/2, /*want_type=*/true);
2038 if (TREE_CODE (type_binding) == TREE_LIST
2039 && TREE_TYPE (type_binding) == error_mark_node)
2040 /* NAME is ambiguous. */
2041 push_class_level_binding (name, type_binding);
2043 pushdecl_class_level (type_binding);
2046 /* Now, do the value binding. */
2047 value_binding = lookup_member (current_class_type, name,
2048 /*protect=*/2, /*want_type=*/false);
2051 && (TREE_CODE (value_binding) == TYPE_DECL
2052 || DECL_CLASS_TEMPLATE_P (value_binding)
2053 || (TREE_CODE (value_binding) == TREE_LIST
2054 && TREE_TYPE (value_binding) == error_mark_node
2055 && (TREE_CODE (TREE_VALUE (value_binding))
2057 /* We found a type-binding, even when looking for a non-type
2058 binding. This means that we already processed this binding
2060 else if (value_binding)
2062 if (TREE_CODE (value_binding) == TREE_LIST
2063 && TREE_TYPE (value_binding) == error_mark_node)
2064 /* NAME is ambiguous. */
2065 push_class_level_binding (name, value_binding);
2068 if (BASELINK_P (value_binding))
2069 /* NAME is some overloaded functions. */
2070 value_binding = BASELINK_FUNCTIONS (value_binding);
2071 pushdecl_class_level (value_binding);
2076 /* Push class-level declarations for any names appearing in BINFO that
2080 dfs_push_type_decls (tree binfo, void *data ATTRIBUTE_UNUSED)
2085 type = BINFO_TYPE (binfo);
2086 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2087 if (DECL_NAME (fields) && TREE_CODE (fields) == TYPE_DECL
2088 && !(!same_type_p (type, current_class_type)
2089 && template_self_reference_p (type, fields)))
2090 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/1);
2092 /* We can't just use BINFO_MARKED because envelope_add_decl uses
2093 DERIVED_FROM_P, which calls get_base_distance. */
2094 BINFO_PUSHDECLS_MARKED (binfo) = 1;
2099 /* Push class-level declarations for any names appearing in BINFO that
2100 are not TYPE_DECLS. */
2103 dfs_push_decls (tree binfo, void *data)
2105 tree type = BINFO_TYPE (binfo);
2109 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2110 if (DECL_NAME (fields)
2111 && TREE_CODE (fields) != TYPE_DECL
2112 && TREE_CODE (fields) != USING_DECL
2113 && !DECL_ARTIFICIAL (fields))
2114 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/0);
2115 else if (TREE_CODE (fields) == FIELD_DECL
2116 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2117 dfs_push_decls (TYPE_BINFO (TREE_TYPE (fields)), data);
2119 method_vec = (CLASS_TYPE_P (type)
2120 ? CLASSTYPE_METHOD_VEC (type) : NULL_TREE);
2122 if (method_vec && TREE_VEC_LENGTH (method_vec) >= 3)
2127 /* Farm out constructors and destructors. */
2128 end = TREE_VEC_END (method_vec);
2130 for (methods = &TREE_VEC_ELT (method_vec, 2);
2131 methods < end && *methods;
2133 setup_class_bindings (DECL_NAME (OVL_CURRENT (*methods)),
2134 /*type_binding_p=*/0);
2137 BINFO_PUSHDECLS_MARKED (binfo) = 0;
2142 /* When entering the scope of a class, we cache all of the
2143 fields that that class provides within its inheritance
2144 lattice. Where ambiguities result, we mark them
2145 with `error_mark_node' so that if they are encountered
2146 without explicit qualification, we can emit an error
2150 push_class_decls (tree type)
2152 search_stack = push_search_level (search_stack, &search_obstack);
2154 /* Enter type declarations and mark. */
2155 dfs_walk (TYPE_BINFO (type), dfs_push_type_decls, unmarked_pushdecls_p, 0);
2157 /* Enter non-type declarations and unmark. */
2158 dfs_walk (TYPE_BINFO (type), dfs_push_decls, marked_pushdecls_p, 0);
2161 /* Here's a subroutine we need because C lacks lambdas. */
2164 dfs_unuse_fields (tree binfo, void *data ATTRIBUTE_UNUSED)
2166 tree type = TREE_TYPE (binfo);
2169 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2171 if (TREE_CODE (fields) != FIELD_DECL || DECL_ARTIFICIAL (fields))
2174 TREE_USED (fields) = 0;
2175 if (DECL_NAME (fields) == NULL_TREE
2176 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2177 unuse_fields (TREE_TYPE (fields));
2184 unuse_fields (tree type)
2186 dfs_walk (TYPE_BINFO (type), dfs_unuse_fields, unmarkedp, 0);
2192 /* We haven't pushed a search level when dealing with cached classes,
2193 so we'd better not try to pop it. */
2195 search_stack = pop_search_level (search_stack);
2199 print_search_statistics ()
2201 #ifdef GATHER_STATISTICS
2202 fprintf (stderr, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
2203 n_fields_searched, n_calls_lookup_field, n_calls_lookup_field_1);
2204 fprintf (stderr, "%d fnfields searched in %d calls to lookup_fnfields\n",
2205 n_outer_fields_searched, n_calls_lookup_fnfields);
2206 fprintf (stderr, "%d calls to get_base_type\n", n_calls_get_base_type);
2207 #else /* GATHER_STATISTICS */
2208 fprintf (stderr, "no search statistics\n");
2209 #endif /* GATHER_STATISTICS */
2213 init_search_processing ()
2215 gcc_obstack_init (&search_obstack);
2219 reinit_search_statistics ()
2221 #ifdef GATHER_STATISTICS
2222 n_fields_searched = 0;
2223 n_calls_lookup_field = 0, n_calls_lookup_field_1 = 0;
2224 n_calls_lookup_fnfields = 0, n_calls_lookup_fnfields_1 = 0;
2225 n_calls_get_base_type = 0;
2226 n_outer_fields_searched = 0;
2227 n_contexts_saved = 0;
2228 #endif /* GATHER_STATISTICS */
2232 add_conversions (tree binfo, void *data)
2235 tree method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
2236 tree *conversions = (tree *) data;
2238 /* Some builtin types have no method vector, not even an empty one. */
2242 for (i = 2; i < TREE_VEC_LENGTH (method_vec); ++i)
2244 tree tmp = TREE_VEC_ELT (method_vec, i);
2247 if (!tmp || ! DECL_CONV_FN_P (OVL_CURRENT (tmp)))
2250 name = DECL_NAME (OVL_CURRENT (tmp));
2252 /* Make sure we don't already have this conversion. */
2253 if (! IDENTIFIER_MARKED (name))
2255 *conversions = tree_cons (binfo, tmp, *conversions);
2256 IDENTIFIER_MARKED (name) = 1;
2262 /* Return a TREE_LIST containing all the non-hidden user-defined
2263 conversion functions for TYPE (and its base-classes). The
2264 TREE_VALUE of each node is a FUNCTION_DECL or an OVERLOAD
2265 containing the conversion functions. The TREE_PURPOSE is the BINFO
2266 from which the conversion functions in this node were selected. */
2269 lookup_conversions (tree type)
2272 tree conversions = NULL_TREE;
2274 complete_type (type);
2275 bfs_walk (TYPE_BINFO (type), add_conversions, 0, &conversions);
2277 for (t = conversions; t; t = TREE_CHAIN (t))
2278 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (t)))) = 0;
2289 /* Check whether the empty class indicated by EMPTY_BINFO is also present
2290 at offset 0 in COMPARE_TYPE, and set found_overlap if so. */
2293 dfs_check_overlap (tree empty_binfo, void *data)
2295 struct overlap_info *oi = (struct overlap_info *) data;
2297 for (binfo = TYPE_BINFO (oi->compare_type);
2299 binfo = BINFO_BASETYPE (binfo, 0))
2301 if (BINFO_TYPE (binfo) == BINFO_TYPE (empty_binfo))
2303 oi->found_overlap = 1;
2306 else if (BINFO_BASETYPES (binfo) == NULL_TREE)
2313 /* Trivial function to stop base traversal when we find something. */
2316 dfs_no_overlap_yet (tree derived, int ix, void *data)
2318 tree binfo = BINFO_BASETYPE (derived, ix);
2319 struct overlap_info *oi = (struct overlap_info *) data;
2321 return !oi->found_overlap ? binfo : NULL_TREE;
2324 /* Returns nonzero if EMPTY_TYPE or any of its bases can also be found at
2325 offset 0 in NEXT_TYPE. Used in laying out empty base class subobjects. */
2328 types_overlap_p (tree empty_type, tree next_type)
2330 struct overlap_info oi;
2332 if (! IS_AGGR_TYPE (next_type))
2334 oi.compare_type = next_type;
2335 oi.found_overlap = 0;
2336 dfs_walk (TYPE_BINFO (empty_type), dfs_check_overlap,
2337 dfs_no_overlap_yet, &oi);
2338 return oi.found_overlap;
2341 /* Given a vtable VAR, determine which of the inherited classes the vtable
2342 inherits (in a loose sense) functions from.
2344 FIXME: This does not work with the new ABI. */
2347 binfo_for_vtable (tree var)
2349 tree main_binfo = TYPE_BINFO (DECL_CONTEXT (var));
2350 tree binfos = TYPE_BINFO_BASETYPES (BINFO_TYPE (main_binfo));
2351 int n_baseclasses = CLASSTYPE_N_BASECLASSES (BINFO_TYPE (main_binfo));
2354 for (i = 0; i < n_baseclasses; i++)
2356 tree base_binfo = TREE_VEC_ELT (binfos, i);
2357 if (base_binfo != NULL_TREE && BINFO_VTABLE (base_binfo) == var)
2361 /* If no secondary base classes matched, return the primary base, if
2363 if (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (main_binfo)))
2364 return get_primary_binfo (main_binfo);
2369 /* Returns the binfo of the first direct or indirect virtual base derived
2370 from BINFO, or NULL if binfo is not via virtual. */
2373 binfo_from_vbase (tree binfo)
2375 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
2377 if (TREE_VIA_VIRTUAL (binfo))
2383 /* Returns the binfo of the first direct or indirect virtual base derived
2384 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2388 binfo_via_virtual (tree binfo, tree limit)
2390 for (; binfo && (!limit || !same_type_p (BINFO_TYPE (binfo), limit));
2391 binfo = BINFO_INHERITANCE_CHAIN (binfo))
2393 if (TREE_VIA_VIRTUAL (binfo))
2399 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2400 Find the equivalent binfo within whatever graph HERE is located.
2401 This is the inverse of original_binfo. */
2404 copied_binfo (tree binfo, tree here)
2406 tree result = NULL_TREE;
2408 if (TREE_VIA_VIRTUAL (binfo))
2412 for (t = here; BINFO_INHERITANCE_CHAIN (t);
2413 t = BINFO_INHERITANCE_CHAIN (t))
2416 result = purpose_member (BINFO_TYPE (binfo),
2417 CLASSTYPE_VBASECLASSES (BINFO_TYPE (t)));
2418 result = TREE_VALUE (result);
2420 else if (BINFO_INHERITANCE_CHAIN (binfo))
2425 base_binfos = copied_binfo (BINFO_INHERITANCE_CHAIN (binfo), here);
2426 base_binfos = BINFO_BASETYPES (base_binfos);
2427 n = TREE_VEC_LENGTH (base_binfos);
2428 for (ix = 0; ix != n; ix++)
2430 tree base = TREE_VEC_ELT (base_binfos, ix);
2432 if (BINFO_TYPE (base) == BINFO_TYPE (binfo))
2441 my_friendly_assert (BINFO_TYPE (here) == BINFO_TYPE (binfo), 20030202);
2445 my_friendly_assert (result, 20030202);
2449 /* BINFO is some base binfo of HERE, within some other
2450 hierachy. Return the equivalent binfo, but in the hierarchy
2451 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2452 is not a base binfo of HERE, returns NULL_TREE. */
2455 original_binfo (tree binfo, tree here)
2459 if (BINFO_TYPE (binfo) == BINFO_TYPE (here))
2461 else if (TREE_VIA_VIRTUAL (binfo))
2463 result = purpose_member (BINFO_TYPE (binfo),
2464 CLASSTYPE_VBASECLASSES (BINFO_TYPE (here)));
2466 result = TREE_VALUE (result);
2468 else if (BINFO_INHERITANCE_CHAIN (binfo))
2472 base_binfos = original_binfo (BINFO_INHERITANCE_CHAIN (binfo), here);
2477 base_binfos = BINFO_BASETYPES (base_binfos);
2478 n = TREE_VEC_LENGTH (base_binfos);
2479 for (ix = 0; ix != n; ix++)
2481 tree base = TREE_VEC_ELT (base_binfos, ix);
2483 if (BINFO_TYPE (base) == BINFO_TYPE (binfo))