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 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GNU CC.
9 GNU CC 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 GNU CC 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 GNU CC; 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. */
37 #define obstack_chunk_alloc xmalloc
38 #define obstack_chunk_free free
42 /* Obstack used for remembering decision points of breadth-first. */
44 static struct obstack search_obstack;
46 /* Methods for pushing and popping objects to and from obstacks. */
49 push_stack_level (obstack, tp, size)
50 struct obstack *obstack;
51 char *tp; /* Sony NewsOS 5.0 compiler doesn't like void * here. */
54 struct stack_level *stack;
55 obstack_grow (obstack, tp, size);
56 stack = (struct stack_level *) ((char*)obstack_next_free (obstack) - size);
57 obstack_finish (obstack);
58 stack->obstack = obstack;
59 stack->first = (tree *) obstack_base (obstack);
60 stack->limit = obstack_room (obstack) / sizeof (tree *);
65 pop_stack_level (stack)
66 struct stack_level *stack;
68 struct stack_level *tem = stack;
69 struct obstack *obstack = tem->obstack;
71 obstack_free (obstack, tem);
75 #define search_level stack_level
76 static struct search_level *search_stack;
80 /* The class dominating the hierarchy. */
82 /* A pointer to a complete object of the indicated TYPE. */
87 static tree lookup_field_1 PARAMS ((tree, tree));
88 static int is_subobject_of_p PARAMS ((tree, tree, tree));
89 static tree dfs_check_overlap PARAMS ((tree, void *));
90 static tree dfs_no_overlap_yet PARAMS ((tree, void *));
91 static base_kind lookup_base_r
92 PARAMS ((tree, tree, base_access, int, int, int, tree *));
93 static int dynamic_cast_base_recurse PARAMS ((tree, tree, int, tree *));
94 static tree marked_pushdecls_p PARAMS ((tree, void *));
95 static tree unmarked_pushdecls_p PARAMS ((tree, void *));
96 static tree dfs_debug_unmarkedp PARAMS ((tree, void *));
97 static tree dfs_debug_mark PARAMS ((tree, void *));
98 static tree dfs_get_vbase_types PARAMS ((tree, void *));
99 static tree dfs_push_type_decls PARAMS ((tree, void *));
100 static tree dfs_push_decls PARAMS ((tree, void *));
101 static tree dfs_unuse_fields PARAMS ((tree, void *));
102 static tree add_conversions PARAMS ((tree, void *));
103 static int covariant_return_p PARAMS ((tree, tree));
104 static int look_for_overrides_r PARAMS ((tree, tree));
105 static struct search_level *push_search_level
106 PARAMS ((struct stack_level *, struct obstack *));
107 static struct search_level *pop_search_level
108 PARAMS ((struct stack_level *));
110 PARAMS ((tree, tree (*) (tree, void *), tree (*) (tree, void *),
112 static tree lookup_field_queue_p PARAMS ((tree, void *));
113 static int shared_member_p PARAMS ((tree));
114 static tree lookup_field_r PARAMS ((tree, void *));
115 static tree canonical_binfo PARAMS ((tree));
116 static tree shared_marked_p PARAMS ((tree, void *));
117 static tree shared_unmarked_p PARAMS ((tree, void *));
118 static int dependent_base_p PARAMS ((tree));
119 static tree dfs_accessible_queue_p PARAMS ((tree, void *));
120 static tree dfs_accessible_p PARAMS ((tree, void *));
121 static tree dfs_access_in_type PARAMS ((tree, void *));
122 static access_kind access_in_type PARAMS ((tree, tree));
123 static tree dfs_canonical_queue PARAMS ((tree, void *));
124 static tree dfs_assert_unmarked_p PARAMS ((tree, void *));
125 static void assert_canonical_unmarked PARAMS ((tree));
126 static int protected_accessible_p PARAMS ((tree, tree, tree));
127 static int friend_accessible_p PARAMS ((tree, tree, tree));
128 static void setup_class_bindings PARAMS ((tree, int));
129 static int template_self_reference_p PARAMS ((tree, tree));
130 static tree dfs_find_vbase_instance PARAMS ((tree, void *));
131 static tree dfs_get_pure_virtuals PARAMS ((tree, void *));
132 static tree dfs_build_inheritance_graph_order PARAMS ((tree, void *));
134 /* Allocate a level of searching. */
136 static struct search_level *
137 push_search_level (stack, obstack)
138 struct stack_level *stack;
139 struct obstack *obstack;
141 struct search_level tem;
144 return push_stack_level (obstack, (char *)&tem, sizeof (tem));
147 /* Discard a level of search allocation. */
149 static struct search_level *
150 pop_search_level (obstack)
151 struct stack_level *obstack;
153 register struct search_level *stack = pop_stack_level (obstack);
158 /* Variables for gathering statistics. */
159 #ifdef GATHER_STATISTICS
160 static int n_fields_searched;
161 static int n_calls_lookup_field, n_calls_lookup_field_1;
162 static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1;
163 static int n_calls_get_base_type;
164 static int n_outer_fields_searched;
165 static int n_contexts_saved;
166 #endif /* GATHER_STATISTICS */
169 /* Worker for lookup_base. BINFO is the binfo we are searching at,
170 BASE is the RECORD_TYPE we are searching for. ACCESS is the
171 required access checks. WITHIN_CURRENT_SCOPE, IS_NON_PUBLIC and
172 IS_VIRTUAL indicate how BINFO was reached from the start of the
173 search. WITHIN_CURRENT_SCOPE is true if we met the current scope,
174 or friend thereof (this allows us to determine whether a protected
175 base is accessible or not). IS_NON_PUBLIC indicates whether BINFO
176 is accessible and IS_VIRTUAL indicates if it is morally virtual.
178 If BINFO is of the required type, then *BINFO_PTR is examined to
179 compare with any other instance of BASE we might have already
180 discovered. *BINFO_PTR is initialized and a base_kind return value
181 indicates what kind of base was located.
183 Otherwise BINFO's bases are searched. */
186 lookup_base_r (binfo, base, access, within_current_scope,
187 is_non_public, is_virtual, binfo_ptr)
190 int within_current_scope;
191 int is_non_public; /* inside a non-public part */
192 int is_virtual; /* inside a virtual part */
197 base_kind found = bk_not_base;
199 if (access == ba_check
200 && !within_current_scope
201 && is_friend (BINFO_TYPE (binfo), current_scope ()))
203 /* Do not clear is_non_public here. If A is a private base of B, A
204 is not allowed to convert a B* to an A*. */
205 within_current_scope = 1;
208 if (same_type_p (BINFO_TYPE (binfo), base))
210 /* We have found a base. Check against what we have found
212 found = bk_same_type;
214 found = bk_via_virtual;
216 found = bk_inaccessible;
220 else if (!is_virtual || !tree_int_cst_equal (BINFO_OFFSET (binfo),
221 BINFO_OFFSET (*binfo_ptr)))
223 if (access != ba_any)
225 else if (!is_virtual)
226 /* Prefer a non-virtual base. */
234 bases = BINFO_BASETYPES (binfo);
238 for (i = TREE_VEC_LENGTH (bases); i--;)
240 tree base_binfo = TREE_VEC_ELT (bases, i);
241 int this_non_public = is_non_public;
242 int this_virtual = is_virtual;
245 if (access <= ba_ignore)
247 else if (TREE_VIA_PUBLIC (base_binfo))
249 else if (access == ba_not_special)
251 else if (TREE_VIA_PROTECTED (base_binfo) && within_current_scope)
253 else if (is_friend (BINFO_TYPE (binfo), current_scope ()))
258 if (TREE_VIA_VIRTUAL (base_binfo))
261 bk = lookup_base_r (base_binfo, base,
262 access, within_current_scope,
263 this_non_public, this_virtual,
269 if (access != ba_any)
274 case bk_inaccessible:
275 if (found == bk_not_base)
277 my_friendly_assert (found == bk_via_virtual
278 || found == bk_inaccessible, 20010723);
286 my_friendly_assert (found == bk_not_base, 20010723);
291 if (found != bk_ambig)
302 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
303 ACCESS specifies. Return the binfo we discover (which might not be
304 canonical). If KIND_PTR is non-NULL, fill with information about
305 what kind of base we discovered.
307 If ba_quiet bit is set in ACCESS, then do not issue an error, and
308 return NULL_TREE for failure. */
311 lookup_base (t, base, access, kind_ptr)
316 tree binfo = NULL; /* The binfo we've found so far. */
319 if (t == error_mark_node || base == error_mark_node)
322 *kind_ptr = bk_not_base;
323 return error_mark_node;
325 my_friendly_assert (TYPE_P (t) && TYPE_P (base), 20011127);
327 /* Ensure that the types are instantiated. */
328 t = complete_type (TYPE_MAIN_VARIANT (t));
329 base = complete_type (TYPE_MAIN_VARIANT (base));
331 bk = lookup_base_r (TYPE_BINFO (t), base, access & ~ba_quiet,
336 case bk_inaccessible:
338 if (!(access & ba_quiet))
340 error ("`%T' is an inaccessible base of `%T'", base, t);
341 binfo = error_mark_node;
345 if (access != ba_any)
348 if (!(access & ba_quiet))
350 error ("`%T' is an ambiguous base of `%T'", base, t);
351 binfo = error_mark_node;
364 /* Worker function for get_dynamic_cast_base_type. */
367 dynamic_cast_base_recurse (subtype, binfo, via_virtual, offset_ptr)
377 if (BINFO_TYPE (binfo) == subtype)
383 *offset_ptr = BINFO_OFFSET (binfo);
388 binfos = BINFO_BASETYPES (binfo);
389 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
390 for (i = 0; i < n_baselinks; i++)
392 tree base_binfo = TREE_VEC_ELT (binfos, i);
395 if (!TREE_VIA_PUBLIC (base_binfo))
397 rval = dynamic_cast_base_recurse
398 (subtype, base_binfo,
399 via_virtual || TREE_VIA_VIRTUAL (base_binfo), offset_ptr);
403 worst = worst >= 0 ? -3 : worst;
406 else if (rval == -3 && worst != -1)
412 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
413 started from is related to the required TARGET type, in order to optimize
414 the inheritance graph search. This information is independent of the
415 current context, and ignores private paths, hence get_base_distance is
416 inappropriate. Return a TREE specifying the base offset, BOFF.
417 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
418 and there are no public virtual SUBTYPE bases.
419 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
420 BOFF == -2, SUBTYPE is not a public base.
421 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
424 get_dynamic_cast_base_type (subtype, target)
428 tree offset = NULL_TREE;
429 int boff = dynamic_cast_base_recurse (subtype, TYPE_BINFO (target),
434 offset = build_int_2 (boff, -1);
435 TREE_TYPE (offset) = ssizetype;
439 /* Search for a member with name NAME in a multiple inheritance lattice
440 specified by TYPE. If it does not exist, return NULL_TREE.
441 If the member is ambiguously referenced, return `error_mark_node'.
442 Otherwise, return the FIELD_DECL. */
444 /* Do a 1-level search for NAME as a member of TYPE. The caller must
445 figure out whether it can access this field. (Since it is only one
446 level, this is reasonable.) */
449 lookup_field_1 (type, name)
454 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
455 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM
456 || TREE_CODE (type) == TYPENAME_TYPE)
457 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
458 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
459 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
460 the code often worked even when we treated the index as a list
462 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
466 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
467 && DECL_SORTED_FIELDS (TYPE_NAME (type)))
469 tree *fields = &TREE_VEC_ELT (DECL_SORTED_FIELDS (TYPE_NAME (type)), 0);
470 int lo = 0, hi = TREE_VEC_LENGTH (DECL_SORTED_FIELDS (TYPE_NAME (type)));
477 #ifdef GATHER_STATISTICS
479 #endif /* GATHER_STATISTICS */
481 if (DECL_NAME (fields[i]) > name)
483 else if (DECL_NAME (fields[i]) < name)
487 /* We might have a nested class and a field with the
488 same name; we sorted them appropriately via
489 field_decl_cmp, so just look for the last field with
492 && DECL_NAME (fields[i+1]) == name)
500 field = TYPE_FIELDS (type);
502 #ifdef GATHER_STATISTICS
503 n_calls_lookup_field_1++;
504 #endif /* GATHER_STATISTICS */
507 #ifdef GATHER_STATISTICS
509 #endif /* GATHER_STATISTICS */
510 my_friendly_assert (DECL_P (field), 0);
511 if (DECL_NAME (field) == NULL_TREE
512 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
514 tree temp = lookup_field_1 (TREE_TYPE (field), name);
518 if (TREE_CODE (field) == USING_DECL)
519 /* For now, we're just treating member using declarations as
520 old ARM-style access declarations. Thus, there's no reason
521 to return a USING_DECL, and the rest of the compiler can't
522 handle it. Once the class is defined, these are purged
523 from TYPE_FIELDS anyhow; see handle_using_decl. */
525 else if (DECL_NAME (field) == name)
527 field = TREE_CHAIN (field);
530 if (name == vptr_identifier)
532 /* Give the user what s/he thinks s/he wants. */
533 if (TYPE_POLYMORPHIC_P (type))
534 return TYPE_VFIELD (type);
539 /* There are a number of cases we need to be aware of here:
540 current_class_type current_function_decl
547 Those last two make life interesting. If we're in a function which is
548 itself inside a class, we need decls to go into the fn's decls (our
549 second case below). But if we're in a class and the class itself is
550 inside a function, we need decls to go into the decls for the class. To
551 achieve this last goal, we must see if, when both current_class_ptr and
552 current_function_decl are set, the class was declared inside that
553 function. If so, we know to put the decls into the class's scope. */
558 if (current_function_decl == NULL_TREE)
559 return current_class_type;
560 if (current_class_type == NULL_TREE)
561 return current_function_decl;
562 if ((DECL_FUNCTION_MEMBER_P (current_function_decl)
563 && same_type_p (DECL_CONTEXT (current_function_decl),
565 || (DECL_FRIEND_CONTEXT (current_function_decl)
566 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl),
567 current_class_type)))
568 return current_function_decl;
570 return current_class_type;
573 /* Returns non-zero if we are currently in a function scope. Note
574 that this function returns zero if we are within a local class, but
575 not within a member function body of the local class. */
578 at_function_scope_p ()
580 tree cs = current_scope ();
581 return cs && TREE_CODE (cs) == FUNCTION_DECL;
584 /* Returns true if the innermost active scope is a class scope. */
589 tree cs = current_scope ();
590 return cs && TYPE_P (cs);
593 /* Return the scope of DECL, as appropriate when doing name-lookup. */
596 context_for_name_lookup (decl)
601 For the purposes of name lookup, after the anonymous union
602 definition, the members of the anonymous union are considered to
603 have been defined in the scope in which the anonymous union is
605 tree context = DECL_CONTEXT (decl);
607 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context))
608 context = TYPE_CONTEXT (context);
610 context = global_namespace;
615 /* Return a canonical BINFO if BINFO is a virtual base, or just BINFO
619 canonical_binfo (binfo)
622 return (TREE_VIA_VIRTUAL (binfo)
623 ? TYPE_BINFO (BINFO_TYPE (binfo)) : binfo);
626 /* A queue function that simply ensures that we walk into the
627 canonical versions of virtual bases. */
630 dfs_canonical_queue (binfo, data)
632 void *data ATTRIBUTE_UNUSED;
634 return canonical_binfo (binfo);
637 /* Called via dfs_walk from assert_canonical_unmarked. */
640 dfs_assert_unmarked_p (binfo, data)
642 void *data ATTRIBUTE_UNUSED;
644 my_friendly_assert (!BINFO_MARKED (binfo), 0);
648 /* Asserts that all the nodes below BINFO (using the canonical
649 versions of virtual bases) are unmarked. */
652 assert_canonical_unmarked (binfo)
655 dfs_walk (binfo, dfs_assert_unmarked_p, dfs_canonical_queue, 0);
658 /* If BINFO is marked, return a canonical version of BINFO.
659 Otherwise, return NULL_TREE. */
662 shared_marked_p (binfo, data)
666 binfo = canonical_binfo (binfo);
667 return markedp (binfo, data);
670 /* If BINFO is not marked, return a canonical version of BINFO.
671 Otherwise, return NULL_TREE. */
674 shared_unmarked_p (binfo, data)
678 binfo = canonical_binfo (binfo);
679 return unmarkedp (binfo, data);
682 /* The accessibility routines use BINFO_ACCESS for scratch space
683 during the computation of the accssibility of some declaration. */
685 #define BINFO_ACCESS(NODE) \
686 ((access_kind) ((TREE_LANG_FLAG_1 (NODE) << 1) | TREE_LANG_FLAG_6 (NODE)))
688 /* Set the access associated with NODE to ACCESS. */
690 #define SET_BINFO_ACCESS(NODE, ACCESS) \
691 ((TREE_LANG_FLAG_1 (NODE) = ((ACCESS) & 2) != 0), \
692 (TREE_LANG_FLAG_6 (NODE) = ((ACCESS) & 1) != 0))
694 /* Called from access_in_type via dfs_walk. Calculate the access to
695 DATA (which is really a DECL) in BINFO. */
698 dfs_access_in_type (binfo, data)
702 tree decl = (tree) data;
703 tree type = BINFO_TYPE (binfo);
704 access_kind access = ak_none;
706 if (context_for_name_lookup (decl) == type)
708 /* If we have desceneded to the scope of DECL, just note the
709 appropriate access. */
710 if (TREE_PRIVATE (decl))
712 else if (TREE_PROTECTED (decl))
713 access = ak_protected;
719 /* First, check for an access-declaration that gives us more
720 access to the DECL. The CONST_DECL for an enumeration
721 constant will not have DECL_LANG_SPECIFIC, and thus no
723 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl))
725 tree decl_access = purpose_member (type, DECL_ACCESS (decl));
727 access = ((access_kind)
728 TREE_INT_CST_LOW (TREE_VALUE (decl_access)));
737 /* Otherwise, scan our baseclasses, and pick the most favorable
739 binfos = BINFO_BASETYPES (binfo);
740 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
741 for (i = 0; i < n_baselinks; ++i)
743 tree base_binfo = TREE_VEC_ELT (binfos, i);
744 access_kind base_access
745 = BINFO_ACCESS (canonical_binfo (base_binfo));
747 if (base_access == ak_none || base_access == ak_private)
748 /* If it was not accessible in the base, or only
749 accessible as a private member, we can't access it
751 base_access = ak_none;
752 else if (TREE_VIA_PROTECTED (base_binfo))
753 /* Public and protected members in the base are
755 base_access = ak_protected;
756 else if (!TREE_VIA_PUBLIC (base_binfo))
757 /* Public and protected members in the base are
759 base_access = ak_private;
761 /* See if the new access, via this base, gives more
762 access than our previous best access. */
763 if (base_access != ak_none
764 && (base_access == ak_public
765 || (base_access == ak_protected
766 && access != ak_public)
767 || (base_access == ak_private
768 && access == ak_none)))
770 access = base_access;
772 /* If the new access is public, we can't do better. */
773 if (access == ak_public)
780 /* Note the access to DECL in TYPE. */
781 SET_BINFO_ACCESS (binfo, access);
783 /* Mark TYPE as visited so that if we reach it again we do not
784 duplicate our efforts here. */
785 SET_BINFO_MARKED (binfo);
790 /* Return the access to DECL in TYPE. */
793 access_in_type (type, decl)
797 tree binfo = TYPE_BINFO (type);
799 /* We must take into account
803 If a name can be reached by several paths through a multiple
804 inheritance graph, the access is that of the path that gives
807 The algorithm we use is to make a post-order depth-first traversal
808 of the base-class hierarchy. As we come up the tree, we annotate
809 each node with the most lenient access. */
810 dfs_walk_real (binfo, 0, dfs_access_in_type, shared_unmarked_p, decl);
811 dfs_walk (binfo, dfs_unmark, shared_marked_p, 0);
812 assert_canonical_unmarked (binfo);
814 return BINFO_ACCESS (binfo);
817 /* Called from dfs_accessible_p via dfs_walk. */
820 dfs_accessible_queue_p (binfo, data)
822 void *data ATTRIBUTE_UNUSED;
824 if (BINFO_MARKED (binfo))
827 /* If this class is inherited via private or protected inheritance,
828 then we can't see it, unless we are a friend of the subclass. */
829 if (!TREE_VIA_PUBLIC (binfo)
830 && !is_friend (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
834 return canonical_binfo (binfo);
837 /* Called from dfs_accessible_p via dfs_walk. */
840 dfs_accessible_p (binfo, data)
844 int protected_ok = data != 0;
847 SET_BINFO_MARKED (binfo);
848 access = BINFO_ACCESS (binfo);
849 if (access == ak_public || (access == ak_protected && protected_ok))
851 else if (access != ak_none
852 && is_friend (BINFO_TYPE (binfo), current_scope ()))
858 /* Returns non-zero if it is OK to access DECL through an object
859 indiated by BINFO in the context of DERIVED. */
862 protected_accessible_p (decl, derived, binfo)
869 /* We're checking this clause from [class.access.base]
871 m as a member of N is protected, and the reference occurs in a
872 member or friend of class N, or in a member or friend of a
873 class P derived from N, where m as a member of P is private or
876 Here DERIVED is a possible P and DECL is m. accessible_p will
877 iterate over various values of N, but the access to m in DERIVED
880 Note that I believe that the passage above is wrong, and should read
881 "...is private or protected or public"; otherwise you get bizarre results
882 whereby a public using-decl can prevent you from accessing a protected
883 member of a base. (jason 2000/02/28) */
885 /* If DERIVED isn't derived from m's class, then it can't be a P. */
886 if (!DERIVED_FROM_P (context_for_name_lookup (decl), derived))
889 access = access_in_type (derived, decl);
891 /* If m is inaccessible in DERIVED, then it's not a P. */
892 if (access == ak_none)
897 When a friend or a member function of a derived class references
898 a protected nonstatic member of a base class, an access check
899 applies in addition to those described earlier in clause
900 _class.access_) Except when forming a pointer to member
901 (_expr.unary.op_), the access must be through a pointer to,
902 reference to, or object of the derived class itself (or any class
903 derived from that class) (_expr.ref_). If the access is to form
904 a pointer to member, the nested-name-specifier shall name the
905 derived class (or any class derived from that class). */
906 if (DECL_NONSTATIC_MEMBER_P (decl))
908 /* We can tell through what the reference is occurring by
909 chasing BINFO up to the root. */
911 while (BINFO_INHERITANCE_CHAIN (t))
912 t = BINFO_INHERITANCE_CHAIN (t);
914 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t)))
921 /* Returns non-zero if SCOPE is a friend of a type which would be able
922 to access DECL through the object indicated by BINFO. */
925 friend_accessible_p (scope, decl, binfo)
930 tree befriending_classes;
936 if (TREE_CODE (scope) == FUNCTION_DECL
937 || DECL_FUNCTION_TEMPLATE_P (scope))
938 befriending_classes = DECL_BEFRIENDING_CLASSES (scope);
939 else if (TYPE_P (scope))
940 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope);
944 for (t = befriending_classes; t; t = TREE_CHAIN (t))
945 if (protected_accessible_p (decl, TREE_VALUE (t), binfo))
948 /* Nested classes are implicitly friends of their enclosing types, as
949 per core issue 45 (this is a change from the standard). */
951 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t))
952 if (protected_accessible_p (decl, t, binfo))
955 if (TREE_CODE (scope) == FUNCTION_DECL
956 || DECL_FUNCTION_TEMPLATE_P (scope))
958 /* Perhaps this SCOPE is a member of a class which is a
960 if (DECL_CLASS_SCOPE_P (decl)
961 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo))
964 /* Or an instantiation of something which is a friend. */
965 if (DECL_TEMPLATE_INFO (scope))
966 return friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo);
968 else if (CLASSTYPE_TEMPLATE_INFO (scope))
969 return friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope), decl, binfo);
974 /* Perform access control on TYPE_DECL VAL, which was looked up in TYPE.
975 This is fairly complex, so here's the design:
977 The lang_extdef nonterminal sets type_lookups to NULL_TREE before we
978 start to process a top-level declaration.
979 As we process the decl-specifier-seq for the declaration, any types we
980 see that might need access control are passed to type_access_control,
981 which defers checking by adding them to type_lookups.
982 When we are done with the decl-specifier-seq, we record the lookups we've
983 seen in the lookups field of the typed_declspecs nonterminal.
984 When we process the first declarator, either in parse_decl or
985 begin_function_definition, we call save_type_access_control,
986 which stores the lookups from the decl-specifier-seq in
987 current_type_lookups.
988 As we finish with each declarator, we process everything in type_lookups
989 via decl_type_access_control, which resets type_lookups to the value of
990 current_type_lookups for subsequent declarators.
991 When we enter a function, we set type_lookups to error_mark_node, so all
992 lookups are processed immediately. */
995 type_access_control (type, val)
998 if (val == NULL_TREE || TREE_CODE (val) != TYPE_DECL
999 || ! DECL_CLASS_SCOPE_P (val))
1002 if (type_lookups == error_mark_node)
1003 enforce_access (type, val);
1004 else if (! accessible_p (type, val))
1005 type_lookups = tree_cons (type, val, type_lookups);
1008 /* DECL is a declaration from a base class of TYPE, which was the
1009 class used to name DECL. Return non-zero if, in the current
1010 context, DECL is accessible. If TYPE is actually a BINFO node,
1011 then we can tell in what context the access is occurring by looking
1012 at the most derived class along the path indicated by BINFO. */
1015 accessible_p (type, decl)
1023 /* Non-zero if it's OK to access DECL if it has protected
1024 accessibility in TYPE. */
1025 int protected_ok = 0;
1027 /* If we're not checking access, everything is accessible. */
1028 if (!flag_access_control)
1031 /* If this declaration is in a block or namespace scope, there's no
1033 if (!TYPE_P (context_for_name_lookup (decl)))
1039 type = BINFO_TYPE (type);
1042 binfo = TYPE_BINFO (type);
1044 /* [class.access.base]
1046 A member m is accessible when named in class N if
1048 --m as a member of N is public, or
1050 --m as a member of N is private, and the reference occurs in a
1051 member or friend of class N, or
1053 --m as a member of N is protected, and the reference occurs in a
1054 member or friend of class N, or in a member or friend of a
1055 class P derived from N, where m as a member of P is private or
1058 --there exists a base class B of N that is accessible at the point
1059 of reference, and m is accessible when named in class B.
1061 We walk the base class hierarchy, checking these conditions. */
1063 /* Figure out where the reference is occurring. Check to see if
1064 DECL is private or protected in this scope, since that will
1065 determine whether protected access is allowed. */
1066 if (current_class_type)
1067 protected_ok = protected_accessible_p (decl, current_class_type, binfo);
1069 /* Now, loop through the classes of which we are a friend. */
1071 protected_ok = friend_accessible_p (current_scope (), decl, binfo);
1073 /* Standardize the binfo that access_in_type will use. We don't
1074 need to know what path was chosen from this point onwards. */
1075 binfo = TYPE_BINFO (type);
1077 /* Compute the accessibility of DECL in the class hierarchy
1078 dominated by type. */
1079 access_in_type (type, decl);
1080 /* Walk the hierarchy again, looking for a base class that allows
1082 t = dfs_walk (binfo, dfs_accessible_p,
1083 dfs_accessible_queue_p,
1084 protected_ok ? &protected_ok : 0);
1085 /* Clear any mark bits. Note that we have to walk the whole tree
1086 here, since we have aborted the previous walk from some point
1087 deep in the tree. */
1088 dfs_walk (binfo, dfs_unmark, dfs_canonical_queue, 0);
1089 assert_canonical_unmarked (binfo);
1091 return t != NULL_TREE;
1094 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1095 found as a base class and sub-object of the object denoted by
1096 BINFO. MOST_DERIVED is the most derived type of the hierarchy being
1100 is_subobject_of_p (parent, binfo, most_derived)
1101 tree parent, binfo, most_derived;
1106 if (parent == binfo)
1109 binfos = BINFO_BASETYPES (binfo);
1110 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
1112 /* Iterate the base types. */
1113 for (i = 0; i < n_baselinks; i++)
1115 tree base_binfo = TREE_VEC_ELT (binfos, i);
1116 if (!CLASS_TYPE_P (TREE_TYPE (base_binfo)))
1117 /* If we see a TEMPLATE_TYPE_PARM, or some such, as a base
1118 class there's no way to descend into it. */
1121 if (is_subobject_of_p (parent,
1122 CANONICAL_BINFO (base_binfo, most_derived),
1129 struct lookup_field_info {
1130 /* The type in which we're looking. */
1132 /* The name of the field for which we're looking. */
1134 /* If non-NULL, the current result of the lookup. */
1136 /* The path to RVAL. */
1138 /* If non-NULL, the lookup was ambiguous, and this is a list of the
1141 /* If non-zero, we are looking for types, not data members. */
1143 /* If non-zero, RVAL was found by looking through a dependent base. */
1144 int from_dep_base_p;
1145 /* If something went wrong, a message indicating what. */
1149 /* Returns non-zero if BINFO is not hidden by the value found by the
1150 lookup so far. If BINFO is hidden, then there's no need to look in
1151 it. DATA is really a struct lookup_field_info. Called from
1152 lookup_field via breadth_first_search. */
1155 lookup_field_queue_p (binfo, data)
1159 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1161 /* Don't look for constructors or destructors in base classes. */
1162 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
1165 /* If this base class is hidden by the best-known value so far, we
1166 don't need to look. */
1167 if (!lfi->from_dep_base_p && lfi->rval_binfo
1168 && is_subobject_of_p (binfo, lfi->rval_binfo, lfi->type))
1171 return CANONICAL_BINFO (binfo, lfi->type);
1174 /* Within the scope of a template class, you can refer to the to the
1175 current specialization with the name of the template itself. For
1178 template <typename T> struct S { S* sp; }
1180 Returns non-zero if DECL is such a declaration in a class TYPE. */
1183 template_self_reference_p (type, decl)
1187 return (CLASSTYPE_USE_TEMPLATE (type)
1188 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
1189 && TREE_CODE (decl) == TYPE_DECL
1190 && DECL_ARTIFICIAL (decl)
1191 && DECL_NAME (decl) == constructor_name (type));
1195 /* Nonzero for a class member means that it is shared between all objects
1198 [class.member.lookup]:If the resulting set of declarations are not all
1199 from sub-objects of the same type, or the set has a nonstatic member
1200 and includes members from distinct sub-objects, there is an ambiguity
1201 and the program is ill-formed.
1203 This function checks that T contains no nonstatic members. */
1209 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \
1210 || TREE_CODE (t) == CONST_DECL)
1212 if (is_overloaded_fn (t))
1214 for (; t; t = OVL_NEXT (t))
1216 tree fn = OVL_CURRENT (t);
1217 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
1225 /* DATA is really a struct lookup_field_info. Look for a field with
1226 the name indicated there in BINFO. If this function returns a
1227 non-NULL value it is the result of the lookup. Called from
1228 lookup_field via breadth_first_search. */
1231 lookup_field_r (binfo, data)
1235 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1236 tree type = BINFO_TYPE (binfo);
1237 tree nval = NULL_TREE;
1238 int from_dep_base_p;
1240 /* First, look for a function. There can't be a function and a data
1241 member with the same name, and if there's a function and a type
1242 with the same name, the type is hidden by the function. */
1243 if (!lfi->want_type)
1245 int idx = lookup_fnfields_1 (type, lfi->name);
1247 nval = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), idx);
1251 /* Look for a data member or type. */
1252 nval = lookup_field_1 (type, lfi->name);
1254 /* If there is no declaration with the indicated name in this type,
1255 then there's nothing to do. */
1259 /* If we're looking up a type (as with an elaborated type specifier)
1260 we ignore all non-types we find. */
1261 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL
1262 && !DECL_CLASS_TEMPLATE_P (nval))
1264 if (lfi->name == TYPE_IDENTIFIER (type))
1266 /* If the aggregate has no user defined constructors, we allow
1267 it to have fields with the same name as the enclosing type.
1268 If we are looking for that name, find the corresponding
1270 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval))
1271 if (DECL_NAME (nval) == lfi->name
1272 && TREE_CODE (nval) == TYPE_DECL)
1279 nval = purpose_member (lfi->name, CLASSTYPE_TAGS (type));
1281 nval = TYPE_MAIN_DECL (TREE_VALUE (nval));
1287 /* You must name a template base class with a template-id. */
1288 if (!same_type_p (type, lfi->type)
1289 && template_self_reference_p (type, nval))
1292 from_dep_base_p = dependent_base_p (binfo);
1293 if (lfi->from_dep_base_p && !from_dep_base_p)
1295 /* If the new declaration is not found via a dependent base, and
1296 the old one was, then we must prefer the new one. We weren't
1297 really supposed to be able to find the old one, so we don't
1298 want to be affected by a specialization. Consider:
1300 struct B { typedef int I; };
1301 template <typename T> struct D1 : virtual public B {};
1302 template <typename T> struct D :
1303 public D1, virtual pubic B { I i; };
1305 The `I' in `D<T>' is unambigousuly `B::I', regardless of how
1306 D1 is specialized. */
1307 lfi->from_dep_base_p = 0;
1308 lfi->rval = NULL_TREE;
1309 lfi->rval_binfo = NULL_TREE;
1310 lfi->ambiguous = NULL_TREE;
1313 else if (lfi->rval_binfo && !lfi->from_dep_base_p && from_dep_base_p)
1314 /* Similarly, if the old declaration was not found via a dependent
1315 base, and the new one is, ignore the new one. */
1318 /* If the lookup already found a match, and the new value doesn't
1319 hide the old one, we might have an ambiguity. */
1320 if (lfi->rval_binfo && !is_subobject_of_p (lfi->rval_binfo, binfo, lfi->type))
1322 if (nval == lfi->rval && shared_member_p (nval))
1323 /* The two things are really the same. */
1325 else if (is_subobject_of_p (binfo, lfi->rval_binfo, lfi->type))
1326 /* The previous value hides the new one. */
1330 /* We have a real ambiguity. We keep a chain of all the
1332 if (!lfi->ambiguous && lfi->rval)
1334 /* This is the first time we noticed an ambiguity. Add
1335 what we previously thought was a reasonable candidate
1337 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE);
1338 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1341 /* Add the new value. */
1342 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous);
1343 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1344 lfi->errstr = "request for member `%D' is ambiguous";
1349 if (from_dep_base_p && TREE_CODE (nval) != TYPE_DECL
1350 /* We need to return a member template class so we can
1351 define partial specializations. Is there a better
1353 && !DECL_CLASS_TEMPLATE_P (nval))
1354 /* The thing we're looking for isn't a type, so the implicit
1355 typename extension doesn't apply, so we just pretend we
1356 didn't find anything. */
1360 lfi->from_dep_base_p = from_dep_base_p;
1361 lfi->rval_binfo = binfo;
1367 /* Look for a member named NAME in an inheritance lattice dominated by
1368 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it is
1369 1, we enforce accessibility. If PROTECT is zero, then, for an
1370 ambiguous lookup, we return NULL. If PROTECT is 1, we issue an
1371 error message. If PROTECT is 2, we return a TREE_LIST whose
1372 TREE_TYPE is error_mark_node and whose TREE_VALUEs are the list of
1373 ambiguous candidates.
1375 WANT_TYPE is 1 when we should only return TYPE_DECLs, if no
1376 TYPE_DECL can be found return NULL_TREE. */
1379 lookup_member (xbasetype, name, protect, want_type)
1380 register tree xbasetype, name;
1381 int protect, want_type;
1383 tree rval, rval_binfo = NULL_TREE;
1384 tree type = NULL_TREE, basetype_path = NULL_TREE;
1385 struct lookup_field_info lfi;
1387 /* rval_binfo is the binfo associated with the found member, note,
1388 this can be set with useful information, even when rval is not
1389 set, because it must deal with ALL members, not just non-function
1390 members. It is used for ambiguity checking and the hidden
1391 checks. Whereas rval is only set if a proper (not hidden)
1392 non-function member is found. */
1394 const char *errstr = 0;
1396 if (xbasetype == current_class_type && TYPE_BEING_DEFINED (xbasetype)
1397 && IDENTIFIER_CLASS_VALUE (name))
1399 tree field = IDENTIFIER_CLASS_VALUE (name);
1400 if (TREE_CODE (field) != FUNCTION_DECL
1401 && ! (want_type && TREE_CODE (field) != TYPE_DECL))
1402 /* We're in the scope of this class, and the value has already
1403 been looked up. Just return the cached value. */
1407 if (TREE_CODE (xbasetype) == TREE_VEC)
1409 type = BINFO_TYPE (xbasetype);
1410 basetype_path = xbasetype;
1412 else if (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype)))
1415 basetype_path = TYPE_BINFO (type);
1416 my_friendly_assert (BINFO_INHERITANCE_CHAIN (basetype_path) == NULL_TREE,
1422 complete_type (type);
1424 #ifdef GATHER_STATISTICS
1425 n_calls_lookup_field++;
1426 #endif /* GATHER_STATISTICS */
1428 memset ((PTR) &lfi, 0, sizeof (lfi));
1431 lfi.want_type = want_type;
1432 bfs_walk (basetype_path, &lookup_field_r, &lookup_field_queue_p, &lfi);
1434 rval_binfo = lfi.rval_binfo;
1436 type = BINFO_TYPE (rval_binfo);
1437 errstr = lfi.errstr;
1439 /* If we are not interested in ambiguities, don't report them;
1440 just return NULL_TREE. */
1441 if (!protect && lfi.ambiguous)
1447 return lfi.ambiguous;
1454 In the case of overloaded function names, access control is
1455 applied to the function selected by overloaded resolution. */
1456 if (rval && protect && !is_overloaded_fn (rval)
1457 && !enforce_access (xbasetype, rval))
1458 return error_mark_node;
1460 if (errstr && protect)
1462 error (errstr, name, type);
1464 print_candidates (lfi.ambiguous);
1465 rval = error_mark_node;
1468 /* If the thing we found was found via the implicit typename
1469 extension, build the typename type. */
1470 if (rval && lfi.from_dep_base_p && !DECL_CLASS_TEMPLATE_P (rval))
1471 rval = TYPE_STUB_DECL (build_typename_type (BINFO_TYPE (basetype_path),
1475 if (rval && is_overloaded_fn (rval))
1477 /* Note that the binfo we put in the baselink is the binfo where
1478 we found the functions, which we need for overload
1479 resolution, but which should not be passed to enforce_access;
1480 rather, enforce_access wants a binfo which refers to the
1481 scope in which we started looking for the function. This
1482 will generally be the binfo passed into this function as
1485 rval = tree_cons (rval_binfo, rval, NULL_TREE);
1486 SET_BASELINK_P (rval);
1492 /* Like lookup_member, except that if we find a function member we
1493 return NULL_TREE. */
1496 lookup_field (xbasetype, name, protect, want_type)
1497 register tree xbasetype, name;
1498 int protect, want_type;
1500 tree rval = lookup_member (xbasetype, name, protect, want_type);
1502 /* Ignore functions. */
1503 if (rval && TREE_CODE (rval) == TREE_LIST)
1509 /* Like lookup_member, except that if we find a non-function member we
1510 return NULL_TREE. */
1513 lookup_fnfields (xbasetype, name, protect)
1514 register tree xbasetype, name;
1517 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/0);
1519 /* Ignore non-functions. */
1520 if (rval && TREE_CODE (rval) != TREE_LIST)
1526 /* TYPE is a class type. Return the index of the fields within
1527 the method vector with name NAME, or -1 is no such field exists. */
1530 lookup_fnfields_1 (type, name)
1533 tree method_vec = (CLASS_TYPE_P (type)
1534 ? CLASSTYPE_METHOD_VEC (type)
1537 if (method_vec != 0)
1540 register tree *methods = &TREE_VEC_ELT (method_vec, 0);
1541 int len = TREE_VEC_LENGTH (method_vec);
1544 #ifdef GATHER_STATISTICS
1545 n_calls_lookup_fnfields_1++;
1546 #endif /* GATHER_STATISTICS */
1548 /* Constructors are first... */
1549 if (name == ctor_identifier)
1550 return (methods[CLASSTYPE_CONSTRUCTOR_SLOT]
1551 ? CLASSTYPE_CONSTRUCTOR_SLOT : -1);
1552 /* and destructors are second. */
1553 if (name == dtor_identifier)
1554 return (methods[CLASSTYPE_DESTRUCTOR_SLOT]
1555 ? CLASSTYPE_DESTRUCTOR_SLOT : -1);
1557 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1558 i < len && methods[i];
1561 #ifdef GATHER_STATISTICS
1562 n_outer_fields_searched++;
1563 #endif /* GATHER_STATISTICS */
1565 tmp = OVL_CURRENT (methods[i]);
1566 if (DECL_NAME (tmp) == name)
1569 /* If the type is complete and we're past the conversion ops,
1570 switch to binary search. */
1571 if (! DECL_CONV_FN_P (tmp)
1572 && COMPLETE_TYPE_P (type))
1574 int lo = i + 1, hi = len;
1580 #ifdef GATHER_STATISTICS
1581 n_outer_fields_searched++;
1582 #endif /* GATHER_STATISTICS */
1584 tmp = DECL_NAME (OVL_CURRENT (methods[i]));
1588 else if (tmp < name)
1597 /* If we didn't find it, it might have been a template
1598 conversion operator to a templated type. If there are any,
1599 such template conversion operators will all be overloaded on
1600 the first conversion slot. (Note that we don't look for this
1601 case above so that we will always find specializations
1603 if (IDENTIFIER_TYPENAME_P (name))
1605 i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1606 if (i < len && methods[i])
1608 tmp = OVL_CURRENT (methods[i]);
1609 if (TREE_CODE (tmp) == TEMPLATE_DECL
1610 && DECL_TEMPLATE_CONV_FN_P (tmp))
1619 /* Walk the class hierarchy dominated by TYPE. FN is called for each
1620 type in the hierarchy, in a breadth-first preorder traversal.
1621 If it ever returns a non-NULL value, that value is immediately
1622 returned and the walk is terminated. At each node, FN is passed a
1623 BINFO indicating the path from the curently visited base-class to
1624 TYPE. Before each base-class is walked QFN is called. If the
1625 value returned is non-zero, the base-class is walked; otherwise it
1626 is not. If QFN is NULL, it is treated as a function which always
1627 returns 1. Both FN and QFN are passed the DATA whenever they are
1631 bfs_walk (binfo, fn, qfn, data)
1633 tree (*fn) PARAMS ((tree, void *));
1634 tree (*qfn) PARAMS ((tree, void *));
1639 tree rval = NULL_TREE;
1640 /* An array of the base classes of BINFO. These will be built up in
1641 breadth-first order, except where QFN prunes the search. */
1642 varray_type bfs_bases;
1644 /* Start with enough room for ten base classes. That will be enough
1645 for most hierarchies. */
1646 VARRAY_TREE_INIT (bfs_bases, 10, "search_stack");
1648 /* Put the first type into the stack. */
1649 VARRAY_TREE (bfs_bases, 0) = binfo;
1652 for (head = 0; head < tail; ++head)
1658 /* Pull the next type out of the queue. */
1659 binfo = VARRAY_TREE (bfs_bases, head);
1661 /* If this is the one we're looking for, we're done. */
1662 rval = (*fn) (binfo, data);
1666 /* Queue up the base types. */
1667 binfos = BINFO_BASETYPES (binfo);
1668 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos): 0;
1669 for (i = 0; i < n_baselinks; i++)
1671 tree base_binfo = TREE_VEC_ELT (binfos, i);
1674 base_binfo = (*qfn) (base_binfo, data);
1678 if (tail == VARRAY_SIZE (bfs_bases))
1679 VARRAY_GROW (bfs_bases, 2 * VARRAY_SIZE (bfs_bases));
1680 VARRAY_TREE (bfs_bases, tail) = base_binfo;
1689 /* Exactly like bfs_walk, except that a depth-first traversal is
1690 performed, and PREFN is called in preorder, while POSTFN is called
1694 dfs_walk_real (binfo, prefn, postfn, qfn, data)
1696 tree (*prefn) PARAMS ((tree, void *));
1697 tree (*postfn) PARAMS ((tree, void *));
1698 tree (*qfn) PARAMS ((tree, void *));
1704 tree rval = NULL_TREE;
1706 /* Call the pre-order walking function. */
1709 rval = (*prefn) (binfo, data);
1714 /* Process the basetypes. */
1715 binfos = BINFO_BASETYPES (binfo);
1716 n_baselinks = BINFO_N_BASETYPES (binfo);
1717 for (i = 0; i < n_baselinks; i++)
1719 tree base_binfo = TREE_VEC_ELT (binfos, i);
1722 base_binfo = (*qfn) (base_binfo, data);
1726 rval = dfs_walk_real (base_binfo, prefn, postfn, qfn, data);
1732 /* Call the post-order walking function. */
1734 rval = (*postfn) (binfo, data);
1739 /* Exactly like bfs_walk, except that a depth-first post-order traversal is
1743 dfs_walk (binfo, fn, qfn, data)
1745 tree (*fn) PARAMS ((tree, void *));
1746 tree (*qfn) PARAMS ((tree, void *));
1749 return dfs_walk_real (binfo, 0, fn, qfn, data);
1752 /* Returns > 0 if a function with type DRETTYPE overriding a function
1753 with type BRETTYPE is covariant, as defined in [class.virtual].
1755 Returns 1 if trivial covariance, 2 if non-trivial (requiring runtime
1756 adjustment), or -1 if pedantically invalid covariance. */
1759 covariant_return_p (brettype, drettype)
1760 tree brettype, drettype;
1765 if (TREE_CODE (brettype) == FUNCTION_DECL)
1767 brettype = TREE_TYPE (TREE_TYPE (brettype));
1768 drettype = TREE_TYPE (TREE_TYPE (drettype));
1770 else if (TREE_CODE (brettype) == METHOD_TYPE)
1772 brettype = TREE_TYPE (brettype);
1773 drettype = TREE_TYPE (drettype);
1776 if (same_type_p (brettype, drettype))
1779 if (! (TREE_CODE (brettype) == TREE_CODE (drettype)
1780 && (TREE_CODE (brettype) == POINTER_TYPE
1781 || TREE_CODE (brettype) == REFERENCE_TYPE)
1782 && TYPE_QUALS (brettype) == TYPE_QUALS (drettype)))
1785 if (! can_convert (brettype, drettype))
1788 brettype = TREE_TYPE (brettype);
1789 drettype = TREE_TYPE (drettype);
1791 /* If not pedantic, allow any standard pointer conversion. */
1792 if (! IS_AGGR_TYPE (drettype) || ! IS_AGGR_TYPE (brettype))
1795 binfo = lookup_base (drettype, brettype, ba_check | ba_quiet, &kind);
1799 if (BINFO_OFFSET_ZEROP (binfo) && kind != bk_via_virtual)
1804 /* Check that virtual overrider OVERRIDER is acceptable for base function
1805 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1808 check_final_overrider (overrider, basefn)
1809 tree overrider, basefn;
1811 tree over_type = TREE_TYPE (overrider);
1812 tree base_type = TREE_TYPE (basefn);
1813 tree over_return = TREE_TYPE (over_type);
1814 tree base_return = TREE_TYPE (base_type);
1815 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type);
1816 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type);
1819 if (same_type_p (base_return, over_return))
1821 else if ((i = covariant_return_p (base_return, over_return)))
1824 sorry ("adjusting pointers for covariant returns");
1826 if (pedantic && i == -1)
1828 cp_pedwarn_at ("invalid covariant return type for `%#D'", overrider);
1829 cp_pedwarn_at (" overriding `%#D' (must be pointer or reference to class)", basefn);
1832 else if (IS_AGGR_TYPE_2 (base_return, over_return)
1833 && same_or_base_type_p (base_return, over_return))
1835 cp_error_at ("invalid covariant return type for `%#D'", overrider);
1836 cp_error_at (" overriding `%#D' (must use pointer or reference)", basefn);
1839 else if (IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider)) == NULL_TREE)
1841 cp_error_at ("conflicting return type specified for `%#D'", overrider);
1842 cp_error_at (" overriding `%#D'", basefn);
1843 SET_IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider),
1844 DECL_CONTEXT (overrider));
1848 /* Check throw specifier is at least as strict. */
1849 if (!comp_except_specs (base_throw, over_throw, 0))
1851 cp_error_at ("looser throw specifier for `%#F'", overrider);
1852 cp_error_at (" overriding `%#F'", basefn);
1858 /* Given a class TYPE, and a function decl FNDECL, look for
1859 virtual functions in TYPE's hierarchy which FNDECL overrides.
1860 We do not look in TYPE itself, only its bases.
1862 Returns non-zero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1863 find that it overrides anything.
1865 We check that every function which is overridden, is correctly
1869 look_for_overrides (type, fndecl)
1872 tree binfo = TYPE_BINFO (type);
1873 tree basebinfos = BINFO_BASETYPES (binfo);
1874 int nbasebinfos = basebinfos ? TREE_VEC_LENGTH (basebinfos) : 0;
1878 for (ix = 0; ix != nbasebinfos; ix++)
1880 tree basetype = BINFO_TYPE (TREE_VEC_ELT (basebinfos, ix));
1882 if (TYPE_POLYMORPHIC_P (basetype))
1883 found += look_for_overrides_r (basetype, fndecl);
1888 /* Look in TYPE for virtual functions with the same signature as FNDECL.
1889 This differs from get_matching_virtual in that it will only return
1890 a function from TYPE. */
1893 look_for_overrides_here (type, fndecl)
1898 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl))
1899 ix = CLASSTYPE_DESTRUCTOR_SLOT;
1901 ix = lookup_fnfields_1 (type, DECL_NAME (fndecl));
1904 tree fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), ix);
1906 for (; fns; fns = OVL_NEXT (fns))
1908 tree fn = OVL_CURRENT (fns);
1910 if (!DECL_VIRTUAL_P (fn))
1911 /* Not a virtual. */;
1912 else if (DECL_CONTEXT (fn) != type)
1913 /* Introduced with a using declaration. */;
1914 else if (DECL_STATIC_FUNCTION_P (fndecl))
1916 tree btypes = TYPE_ARG_TYPES (TREE_TYPE (fn));
1917 tree dtypes = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1918 if (compparms (TREE_CHAIN (btypes), dtypes))
1921 else if (same_signature_p (fndecl, fn))
1928 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1929 TYPE itself and its bases. */
1932 look_for_overrides_r (type, fndecl)
1935 tree fn = look_for_overrides_here (type, fndecl);
1938 if (DECL_STATIC_FUNCTION_P (fndecl))
1940 /* A static member function cannot match an inherited
1941 virtual member function. */
1942 cp_error_at ("`%#D' cannot be declared", fndecl);
1943 cp_error_at (" since `%#D' declared in base class", fn);
1947 /* It's definitely virtual, even if not explicitly set. */
1948 DECL_VIRTUAL_P (fndecl) = 1;
1949 check_final_overrider (fndecl, fn);
1954 /* We failed to find one declared in this class. Look in its bases. */
1955 return look_for_overrides (type, fndecl);
1958 /* A queue function to use with dfs_walk that only walks into
1959 canonical bases. DATA should be the type of the complete object,
1960 or a TREE_LIST whose TREE_PURPOSE is the type of the complete
1961 object. By using this function as a queue function, you will walk
1962 over exactly those BINFOs that actually exist in the complete
1963 object, including those for virtual base classes. If you
1964 SET_BINFO_MARKED for each binfo you process, you are further
1965 guaranteed that you will walk into each virtual base class exactly
1969 dfs_unmarked_real_bases_queue_p (binfo, data)
1973 if (TREE_VIA_VIRTUAL (binfo))
1975 tree type = (tree) data;
1977 if (TREE_CODE (type) == TREE_LIST)
1978 type = TREE_PURPOSE (type);
1979 binfo = binfo_for_vbase (BINFO_TYPE (binfo), type);
1981 return unmarkedp (binfo, NULL);
1984 /* Like dfs_unmarked_real_bases_queue_p but walks only into things
1985 that are marked, rather than unmarked. */
1988 dfs_marked_real_bases_queue_p (binfo, data)
1992 if (TREE_VIA_VIRTUAL (binfo))
1994 tree type = (tree) data;
1996 if (TREE_CODE (type) == TREE_LIST)
1997 type = TREE_PURPOSE (type);
1998 binfo = binfo_for_vbase (BINFO_TYPE (binfo), type);
2000 return markedp (binfo, NULL);
2003 /* A queue function that skips all virtual bases (and their
2007 dfs_skip_vbases (binfo, data)
2009 void *data ATTRIBUTE_UNUSED;
2011 if (TREE_VIA_VIRTUAL (binfo))
2017 /* Called via dfs_walk from dfs_get_pure_virtuals. */
2020 dfs_get_pure_virtuals (binfo, data)
2024 tree type = (tree) data;
2026 /* We're not interested in primary base classes; the derived class
2027 of which they are a primary base will contain the information we
2029 if (!BINFO_PRIMARY_P (binfo))
2033 for (virtuals = BINFO_VIRTUALS (binfo);
2035 virtuals = TREE_CHAIN (virtuals))
2036 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals)))
2037 CLASSTYPE_PURE_VIRTUALS (type)
2038 = tree_cons (NULL_TREE, BV_FN (virtuals),
2039 CLASSTYPE_PURE_VIRTUALS (type));
2042 SET_BINFO_MARKED (binfo);
2047 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
2050 get_pure_virtuals (type)
2055 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
2056 is going to be overridden. */
2057 CLASSTYPE_PURE_VIRTUALS (type) = NULL_TREE;
2058 /* Now, run through all the bases which are not primary bases, and
2059 collect the pure virtual functions. We look at the vtable in
2060 each class to determine what pure virtual functions are present.
2061 (A primary base is not interesting because the derived class of
2062 which it is a primary base will contain vtable entries for the
2063 pure virtuals in the base class. */
2064 dfs_walk (TYPE_BINFO (type), dfs_get_pure_virtuals,
2065 dfs_unmarked_real_bases_queue_p, type);
2066 dfs_walk (TYPE_BINFO (type), dfs_unmark,
2067 dfs_marked_real_bases_queue_p, type);
2069 /* Put the pure virtuals in dfs order. */
2070 CLASSTYPE_PURE_VIRTUALS (type) = nreverse (CLASSTYPE_PURE_VIRTUALS (type));
2072 for (vbases = CLASSTYPE_VBASECLASSES (type);
2074 vbases = TREE_CHAIN (vbases))
2078 for (virtuals = BINFO_VIRTUALS (TREE_VALUE (vbases));
2080 virtuals = TREE_CHAIN (virtuals))
2082 tree base_fndecl = BV_FN (virtuals);
2083 if (DECL_NEEDS_FINAL_OVERRIDER_P (base_fndecl))
2084 error ("`%#D' needs a final overrider", base_fndecl);
2089 /* DEPTH-FIRST SEARCH ROUTINES. */
2092 markedp (binfo, data)
2094 void *data ATTRIBUTE_UNUSED;
2096 return BINFO_MARKED (binfo) ? binfo : NULL_TREE;
2100 unmarkedp (binfo, data)
2102 void *data ATTRIBUTE_UNUSED;
2104 return !BINFO_MARKED (binfo) ? binfo : NULL_TREE;
2108 marked_vtable_pathp (binfo, data)
2110 void *data ATTRIBUTE_UNUSED;
2112 return BINFO_VTABLE_PATH_MARKED (binfo) ? binfo : NULL_TREE;
2116 unmarked_vtable_pathp (binfo, data)
2118 void *data ATTRIBUTE_UNUSED;
2120 return !BINFO_VTABLE_PATH_MARKED (binfo) ? binfo : NULL_TREE;
2124 marked_pushdecls_p (binfo, data)
2126 void *data ATTRIBUTE_UNUSED;
2128 return (CLASS_TYPE_P (BINFO_TYPE (binfo))
2129 && BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
2133 unmarked_pushdecls_p (binfo, data)
2135 void *data ATTRIBUTE_UNUSED;
2137 return (CLASS_TYPE_P (BINFO_TYPE (binfo))
2138 && !BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
2141 /* The worker functions for `dfs_walk'. These do not need to
2142 test anything (vis a vis marking) if they are paired with
2143 a predicate function (above). */
2146 dfs_unmark (binfo, data)
2148 void *data ATTRIBUTE_UNUSED;
2150 CLEAR_BINFO_MARKED (binfo);
2154 /* get virtual base class types.
2155 This adds type to the vbase_types list in reverse dfs order.
2156 Ordering is very important, so don't change it. */
2159 dfs_get_vbase_types (binfo, data)
2163 tree type = (tree) data;
2165 if (TREE_VIA_VIRTUAL (binfo))
2166 CLASSTYPE_VBASECLASSES (type)
2167 = tree_cons (BINFO_TYPE (binfo),
2169 CLASSTYPE_VBASECLASSES (type));
2170 SET_BINFO_MARKED (binfo);
2174 /* Called via dfs_walk from mark_primary_bases. Builds the
2175 inheritance graph order list of BINFOs. */
2178 dfs_build_inheritance_graph_order (binfo, data)
2182 tree *last_binfo = (tree *) data;
2185 TREE_CHAIN (*last_binfo) = binfo;
2186 *last_binfo = binfo;
2187 SET_BINFO_MARKED (binfo);
2191 /* Set CLASSTYPE_VBASECLASSES for TYPE. */
2194 get_vbase_types (type)
2199 CLASSTYPE_VBASECLASSES (type) = NULL_TREE;
2200 dfs_walk (TYPE_BINFO (type), dfs_get_vbase_types, unmarkedp, type);
2201 /* Rely upon the reverse dfs ordering from dfs_get_vbase_types, and now
2202 reverse it so that we get normal dfs ordering. */
2203 CLASSTYPE_VBASECLASSES (type) = nreverse (CLASSTYPE_VBASECLASSES (type));
2204 dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, 0);
2205 /* Thread the BINFOs in inheritance-graph order. */
2207 dfs_walk_real (TYPE_BINFO (type),
2208 dfs_build_inheritance_graph_order,
2212 dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, NULL);
2215 /* Called from find_vbase_instance via dfs_walk. */
2218 dfs_find_vbase_instance (binfo, data)
2222 tree base = TREE_VALUE ((tree) data);
2224 if (BINFO_PRIMARY_P (binfo)
2225 && same_type_p (BINFO_TYPE (binfo), base))
2231 /* Find the real occurrence of the virtual BASE (a class type) in the
2232 hierarchy dominated by TYPE. */
2235 find_vbase_instance (base, type)
2241 instance = binfo_for_vbase (base, type);
2242 if (!BINFO_PRIMARY_P (instance))
2245 return dfs_walk (TYPE_BINFO (type),
2246 dfs_find_vbase_instance,
2248 build_tree_list (type, base));
2252 /* Debug info for C++ classes can get very large; try to avoid
2253 emitting it everywhere.
2255 Note that this optimization wins even when the target supports
2256 BINCL (if only slightly), and reduces the amount of work for the
2260 maybe_suppress_debug_info (t)
2263 /* We can't do the usual TYPE_DECL_SUPPRESS_DEBUG thing with DWARF, which
2264 does not support name references between translation units. It supports
2265 symbolic references between translation units, but only within a single
2266 executable or shared library.
2268 For DWARF 2, we handle TYPE_DECL_SUPPRESS_DEBUG by pretending
2269 that the type was never defined, so we only get the members we
2271 if (write_symbols == DWARF_DEBUG || write_symbols == NO_DEBUG)
2274 /* We might have set this earlier in cp_finish_decl. */
2275 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 0;
2277 /* If we already know how we're handling this class, handle debug info
2279 if (CLASSTYPE_INTERFACE_KNOWN (t))
2281 if (CLASSTYPE_INTERFACE_ONLY (t))
2282 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
2283 /* else don't set it. */
2285 /* If the class has a vtable, write out the debug info along with
2287 else if (TYPE_CONTAINS_VPTR_P (t))
2288 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
2290 /* Otherwise, just emit the debug info normally. */
2293 /* Note that we want debugging information for a base class of a class
2294 whose vtable is being emitted. Normally, this would happen because
2295 calling the constructor for a derived class implies calling the
2296 constructors for all bases, which involve initializing the
2297 appropriate vptr with the vtable for the base class; but in the
2298 presence of optimization, this initialization may be optimized
2299 away, so we tell finish_vtable_vardecl that we want the debugging
2300 information anyway. */
2303 dfs_debug_mark (binfo, data)
2305 void *data ATTRIBUTE_UNUSED;
2307 tree t = BINFO_TYPE (binfo);
2309 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
2314 /* Returns BINFO if we haven't already noted that we want debugging
2315 info for this base class. */
2318 dfs_debug_unmarkedp (binfo, data)
2320 void *data ATTRIBUTE_UNUSED;
2322 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo))
2323 ? binfo : NULL_TREE);
2326 /* Write out the debugging information for TYPE, whose vtable is being
2327 emitted. Also walk through our bases and note that we want to
2328 write out information for them. This avoids the problem of not
2329 writing any debug info for intermediate basetypes whose
2330 constructors, and thus the references to their vtables, and thus
2331 the vtables themselves, were optimized away. */
2334 note_debug_info_needed (type)
2337 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)))
2339 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)) = 0;
2340 rest_of_type_compilation (type, toplevel_bindings_p ());
2343 dfs_walk (TYPE_BINFO (type), dfs_debug_mark, dfs_debug_unmarkedp, 0);
2346 /* Subroutines of push_class_decls (). */
2348 /* Returns 1 iff BINFO is a base we shouldn't really be able to see into,
2349 because it (or one of the intermediate bases) depends on template parms. */
2352 dependent_base_p (binfo)
2355 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
2357 if (currently_open_class (TREE_TYPE (binfo)))
2359 if (uses_template_parms (TREE_TYPE (binfo)))
2366 setup_class_bindings (name, type_binding_p)
2370 tree type_binding = NULL_TREE;
2373 /* If we've already done the lookup for this declaration, we're
2375 if (IDENTIFIER_CLASS_VALUE (name))
2378 /* First, deal with the type binding. */
2381 type_binding = lookup_member (current_class_type, name,
2384 if (TREE_CODE (type_binding) == TREE_LIST
2385 && TREE_TYPE (type_binding) == error_mark_node)
2386 /* NAME is ambiguous. */
2387 push_class_level_binding (name, type_binding);
2389 pushdecl_class_level (type_binding);
2392 /* Now, do the value binding. */
2393 value_binding = lookup_member (current_class_type, name,
2398 && (TREE_CODE (value_binding) == TYPE_DECL
2399 || DECL_CLASS_TEMPLATE_P (value_binding)
2400 || (TREE_CODE (value_binding) == TREE_LIST
2401 && TREE_TYPE (value_binding) == error_mark_node
2402 && (TREE_CODE (TREE_VALUE (value_binding))
2404 /* We found a type-binding, even when looking for a non-type
2405 binding. This means that we already processed this binding
2407 else if (value_binding)
2409 if (TREE_CODE (value_binding) == TREE_LIST
2410 && TREE_TYPE (value_binding) == error_mark_node)
2411 /* NAME is ambiguous. */
2412 push_class_level_binding (name, value_binding);
2415 if (BASELINK_P (value_binding))
2416 /* NAME is some overloaded functions. */
2417 value_binding = TREE_VALUE (value_binding);
2418 pushdecl_class_level (value_binding);
2423 /* Push class-level declarations for any names appearing in BINFO that
2427 dfs_push_type_decls (binfo, data)
2429 void *data ATTRIBUTE_UNUSED;
2434 type = BINFO_TYPE (binfo);
2435 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2436 if (DECL_NAME (fields) && TREE_CODE (fields) == TYPE_DECL
2437 && !(!same_type_p (type, current_class_type)
2438 && template_self_reference_p (type, fields)))
2439 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/1);
2441 /* We can't just use BINFO_MARKED because envelope_add_decl uses
2442 DERIVED_FROM_P, which calls get_base_distance. */
2443 SET_BINFO_PUSHDECLS_MARKED (binfo);
2448 /* Push class-level declarations for any names appearing in BINFO that
2449 are not TYPE_DECLS. */
2452 dfs_push_decls (binfo, data)
2460 type = BINFO_TYPE (binfo);
2461 dep_base_p = (processing_template_decl && type != current_class_type
2462 && dependent_base_p (binfo));
2466 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2467 if (DECL_NAME (fields)
2468 && TREE_CODE (fields) != TYPE_DECL
2469 && TREE_CODE (fields) != USING_DECL)
2470 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/0);
2471 else if (TREE_CODE (fields) == FIELD_DECL
2472 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2473 dfs_push_decls (TYPE_BINFO (TREE_TYPE (fields)), data);
2475 method_vec = (CLASS_TYPE_P (type)
2476 ? CLASSTYPE_METHOD_VEC (type) : NULL_TREE);
2482 /* Farm out constructors and destructors. */
2483 end = TREE_VEC_END (method_vec);
2485 for (methods = &TREE_VEC_ELT (method_vec, 2);
2486 *methods && methods != end;
2488 setup_class_bindings (DECL_NAME (OVL_CURRENT (*methods)),
2489 /*type_binding_p=*/0);
2493 CLEAR_BINFO_PUSHDECLS_MARKED (binfo);
2498 /* When entering the scope of a class, we cache all of the
2499 fields that that class provides within its inheritance
2500 lattice. Where ambiguities result, we mark them
2501 with `error_mark_node' so that if they are encountered
2502 without explicit qualification, we can emit an error
2506 push_class_decls (type)
2509 search_stack = push_search_level (search_stack, &search_obstack);
2511 /* Enter type declarations and mark. */
2512 dfs_walk (TYPE_BINFO (type), dfs_push_type_decls, unmarked_pushdecls_p, 0);
2514 /* Enter non-type declarations and unmark. */
2515 dfs_walk (TYPE_BINFO (type), dfs_push_decls, marked_pushdecls_p, 0);
2518 /* Here's a subroutine we need because C lacks lambdas. */
2521 dfs_unuse_fields (binfo, data)
2523 void *data ATTRIBUTE_UNUSED;
2525 tree type = TREE_TYPE (binfo);
2528 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2530 if (TREE_CODE (fields) != FIELD_DECL)
2533 TREE_USED (fields) = 0;
2534 if (DECL_NAME (fields) == NULL_TREE
2535 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2536 unuse_fields (TREE_TYPE (fields));
2546 dfs_walk (TYPE_BINFO (type), dfs_unuse_fields, unmarkedp, 0);
2552 /* We haven't pushed a search level when dealing with cached classes,
2553 so we'd better not try to pop it. */
2555 search_stack = pop_search_level (search_stack);
2559 print_search_statistics ()
2561 #ifdef GATHER_STATISTICS
2562 fprintf (stderr, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
2563 n_fields_searched, n_calls_lookup_field, n_calls_lookup_field_1);
2564 fprintf (stderr, "%d fnfields searched in %d calls to lookup_fnfields\n",
2565 n_outer_fields_searched, n_calls_lookup_fnfields);
2566 fprintf (stderr, "%d calls to get_base_type\n", n_calls_get_base_type);
2567 #else /* GATHER_STATISTICS */
2568 fprintf (stderr, "no search statistics\n");
2569 #endif /* GATHER_STATISTICS */
2573 init_search_processing ()
2575 gcc_obstack_init (&search_obstack);
2579 reinit_search_statistics ()
2581 #ifdef GATHER_STATISTICS
2582 n_fields_searched = 0;
2583 n_calls_lookup_field = 0, n_calls_lookup_field_1 = 0;
2584 n_calls_lookup_fnfields = 0, n_calls_lookup_fnfields_1 = 0;
2585 n_calls_get_base_type = 0;
2586 n_outer_fields_searched = 0;
2587 n_contexts_saved = 0;
2588 #endif /* GATHER_STATISTICS */
2592 add_conversions (binfo, data)
2597 tree method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
2598 tree *conversions = (tree *) data;
2600 /* Some builtin types have no method vector, not even an empty one. */
2604 for (i = 2; i < TREE_VEC_LENGTH (method_vec); ++i)
2606 tree tmp = TREE_VEC_ELT (method_vec, i);
2609 if (!tmp || ! DECL_CONV_FN_P (OVL_CURRENT (tmp)))
2612 name = DECL_NAME (OVL_CURRENT (tmp));
2614 /* Make sure we don't already have this conversion. */
2615 if (! IDENTIFIER_MARKED (name))
2617 *conversions = tree_cons (binfo, tmp, *conversions);
2618 IDENTIFIER_MARKED (name) = 1;
2624 /* Return a TREE_LIST containing all the non-hidden user-defined
2625 conversion functions for TYPE (and its base-classes). The
2626 TREE_VALUE of each node is a FUNCTION_DECL or an OVERLOAD
2627 containing the conversion functions. The TREE_PURPOSE is the BINFO
2628 from which the conversion functions in this node were selected. */
2631 lookup_conversions (type)
2635 tree conversions = NULL_TREE;
2637 if (COMPLETE_TYPE_P (type))
2638 bfs_walk (TYPE_BINFO (type), add_conversions, 0, &conversions);
2640 for (t = conversions; t; t = TREE_CHAIN (t))
2641 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (t)))) = 0;
2652 /* Check whether the empty class indicated by EMPTY_BINFO is also present
2653 at offset 0 in COMPARE_TYPE, and set found_overlap if so. */
2656 dfs_check_overlap (empty_binfo, data)
2660 struct overlap_info *oi = (struct overlap_info *) data;
2662 for (binfo = TYPE_BINFO (oi->compare_type);
2664 binfo = BINFO_BASETYPE (binfo, 0))
2666 if (BINFO_TYPE (binfo) == BINFO_TYPE (empty_binfo))
2668 oi->found_overlap = 1;
2671 else if (BINFO_BASETYPES (binfo) == NULL_TREE)
2678 /* Trivial function to stop base traversal when we find something. */
2681 dfs_no_overlap_yet (binfo, data)
2685 struct overlap_info *oi = (struct overlap_info *) data;
2686 return !oi->found_overlap ? binfo : NULL_TREE;
2689 /* Returns nonzero if EMPTY_TYPE or any of its bases can also be found at
2690 offset 0 in NEXT_TYPE. Used in laying out empty base class subobjects. */
2693 types_overlap_p (empty_type, next_type)
2694 tree empty_type, next_type;
2696 struct overlap_info oi;
2698 if (! IS_AGGR_TYPE (next_type))
2700 oi.compare_type = next_type;
2701 oi.found_overlap = 0;
2702 dfs_walk (TYPE_BINFO (empty_type), dfs_check_overlap,
2703 dfs_no_overlap_yet, &oi);
2704 return oi.found_overlap;
2707 /* Given a vtable VAR, determine which of the inherited classes the vtable
2708 inherits (in a loose sense) functions from.
2710 FIXME: This does not work with the new ABI. */
2713 binfo_for_vtable (var)
2716 tree main_binfo = TYPE_BINFO (DECL_CONTEXT (var));
2717 tree binfos = TYPE_BINFO_BASETYPES (BINFO_TYPE (main_binfo));
2718 int n_baseclasses = CLASSTYPE_N_BASECLASSES (BINFO_TYPE (main_binfo));
2721 for (i = 0; i < n_baseclasses; i++)
2723 tree base_binfo = TREE_VEC_ELT (binfos, i);
2724 if (base_binfo != NULL_TREE && BINFO_VTABLE (base_binfo) == var)
2728 /* If no secondary base classes matched, return the primary base, if
2730 if (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (main_binfo)))
2731 return get_primary_binfo (main_binfo);
2736 /* Returns the binfo of the first direct or indirect virtual base derived
2737 from BINFO, or NULL if binfo is not via virtual. */
2740 binfo_from_vbase (binfo)
2743 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
2745 if (TREE_VIA_VIRTUAL (binfo))
2751 /* Returns the binfo of the first direct or indirect virtual base derived
2752 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2756 binfo_via_virtual (binfo, limit)
2760 for (; binfo && (!limit || !same_type_p (BINFO_TYPE (binfo), limit));
2761 binfo = BINFO_INHERITANCE_CHAIN (binfo))
2763 if (TREE_VIA_VIRTUAL (binfo))
2769 /* Returns the BINFO (if any) for the virtual baseclass T of the class
2770 C from the CLASSTYPE_VBASECLASSES list. */
2773 binfo_for_vbase (basetype, classtype)
2779 binfo = purpose_member (basetype, CLASSTYPE_VBASECLASSES (classtype));
2780 return binfo ? TREE_VALUE (binfo) : NULL_TREE;