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 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. */
36 #define obstack_chunk_alloc xmalloc
37 #define obstack_chunk_free free
41 /* Obstack used for remembering decision points of breadth-first. */
43 static struct obstack search_obstack;
45 /* Methods for pushing and popping objects to and from obstacks. */
48 push_stack_level (obstack, tp, size)
49 struct obstack *obstack;
50 char *tp; /* Sony NewsOS 5.0 compiler doesn't like void * here. */
53 struct stack_level *stack;
54 obstack_grow (obstack, tp, size);
55 stack = (struct stack_level *) ((char*)obstack_next_free (obstack) - size);
56 obstack_finish (obstack);
57 stack->obstack = obstack;
58 stack->first = (tree *) obstack_base (obstack);
59 stack->limit = obstack_room (obstack) / sizeof (tree *);
64 pop_stack_level (stack)
65 struct stack_level *stack;
67 struct stack_level *tem = stack;
68 struct obstack *obstack = tem->obstack;
70 obstack_free (obstack, tem);
74 #define search_level stack_level
75 static struct search_level *search_stack;
79 /* The class dominating the hierarchy. */
81 /* A pointer to a complete object of the indicated TYPE. */
86 static tree lookup_field_1 PARAMS ((tree, tree));
87 static int is_subobject_of_p PARAMS ((tree, tree, tree));
88 static tree dfs_check_overlap PARAMS ((tree, void *));
89 static tree dfs_no_overlap_yet PARAMS ((tree, void *));
90 static int get_base_distance_recursive
91 PARAMS ((tree, int, int, int, int *, tree *, tree,
92 int, int *, int, int));
93 static base_kind lookup_base_r
94 PARAMS ((tree, tree, base_access,
95 int, int, int, tree *));
96 static int dynamic_cast_base_recurse PARAMS ((tree, tree, int, tree *));
97 static tree marked_pushdecls_p PARAMS ((tree, void *));
98 static tree unmarked_pushdecls_p PARAMS ((tree, void *));
99 static tree dfs_debug_unmarkedp PARAMS ((tree, void *));
100 static tree dfs_debug_mark PARAMS ((tree, void *));
101 static tree dfs_get_vbase_types PARAMS ((tree, void *));
102 static tree dfs_push_type_decls PARAMS ((tree, void *));
103 static tree dfs_push_decls PARAMS ((tree, void *));
104 static tree dfs_unuse_fields PARAMS ((tree, void *));
105 static tree add_conversions PARAMS ((tree, void *));
106 static int covariant_return_p PARAMS ((tree, tree));
107 static int check_final_overrider PARAMS ((tree, tree));
108 static int look_for_overrides_r PARAMS ((tree, tree));
109 static struct search_level *push_search_level
110 PARAMS ((struct stack_level *, struct obstack *));
111 static struct search_level *pop_search_level
112 PARAMS ((struct stack_level *));
114 PARAMS ((tree, tree (*) (tree, void *), tree (*) (tree, void *),
116 static tree lookup_field_queue_p PARAMS ((tree, void *));
117 static int shared_member_p PARAMS ((tree));
118 static tree lookup_field_r PARAMS ((tree, void *));
119 static tree canonical_binfo PARAMS ((tree));
120 static tree shared_marked_p PARAMS ((tree, void *));
121 static tree shared_unmarked_p PARAMS ((tree, void *));
122 static int dependent_base_p PARAMS ((tree));
123 static tree dfs_accessible_queue_p PARAMS ((tree, void *));
124 static tree dfs_accessible_p PARAMS ((tree, void *));
125 static tree dfs_access_in_type PARAMS ((tree, void *));
126 static access_kind access_in_type PARAMS ((tree, tree));
127 static tree dfs_canonical_queue PARAMS ((tree, void *));
128 static tree dfs_assert_unmarked_p PARAMS ((tree, void *));
129 static void assert_canonical_unmarked PARAMS ((tree));
130 static int protected_accessible_p PARAMS ((tree, tree, tree));
131 static int friend_accessible_p PARAMS ((tree, tree, tree));
132 static void setup_class_bindings PARAMS ((tree, int));
133 static int template_self_reference_p PARAMS ((tree, tree));
134 static tree get_shared_vbase_if_not_primary PARAMS ((tree, void *));
135 static tree dfs_find_vbase_instance PARAMS ((tree, void *));
136 static tree dfs_get_pure_virtuals PARAMS ((tree, void *));
137 static tree dfs_build_inheritance_graph_order PARAMS ((tree, void *));
139 /* Allocate a level of searching. */
141 static struct search_level *
142 push_search_level (stack, obstack)
143 struct stack_level *stack;
144 struct obstack *obstack;
146 struct search_level tem;
149 return push_stack_level (obstack, (char *)&tem, sizeof (tem));
152 /* Discard a level of search allocation. */
154 static struct search_level *
155 pop_search_level (obstack)
156 struct stack_level *obstack;
158 register struct search_level *stack = pop_stack_level (obstack);
163 /* Variables for gathering statistics. */
164 #ifdef GATHER_STATISTICS
165 static int n_fields_searched;
166 static int n_calls_lookup_field, n_calls_lookup_field_1;
167 static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1;
168 static int n_calls_get_base_type;
169 static int n_outer_fields_searched;
170 static int n_contexts_saved;
171 #endif /* GATHER_STATISTICS */
174 /* Check whether the type given in BINFO is derived from PARENT. If
175 it isn't, return 0. If it is, but the derivation is MI-ambiguous
176 AND protect != 0, emit an error message and return error_mark_node.
178 Otherwise, if TYPE is derived from PARENT, return the actual base
179 information, unless a one of the protection violations below
180 occurs, in which case emit an error message and return error_mark_node.
182 If PROTECT is 1, then check if access to a public field of PARENT
183 would be private. Also check for ambiguity. */
186 get_binfo (parent, binfo, protect)
187 register tree parent, binfo;
190 tree type = NULL_TREE;
192 tree rval = NULL_TREE;
194 if (TREE_CODE (parent) == TREE_VEC)
195 parent = BINFO_TYPE (parent);
196 else if (! IS_AGGR_TYPE_CODE (TREE_CODE (parent)))
197 my_friendly_abort (89);
199 if (TREE_CODE (binfo) == TREE_VEC)
200 type = BINFO_TYPE (binfo);
201 else if (IS_AGGR_TYPE_CODE (TREE_CODE (binfo)))
204 my_friendly_abort (90);
206 dist = get_base_distance (parent, binfo, protect, &rval);
210 cp_error ("fields of `%T' are inaccessible in `%T' due to private inheritance",
212 return error_mark_node;
214 else if (dist == -2 && protect)
216 cp_error ("type `%T' is ambiguous base class for type `%T'", parent,
218 return error_mark_node;
224 /* This is the newer depth first get_base_distance routine. */
227 get_base_distance_recursive (binfo, depth, is_private, rval,
228 rval_private_ptr, new_binfo_ptr, parent,
229 protect, via_virtual_ptr, via_virtual,
230 current_scope_in_chain)
232 int depth, is_private, rval;
233 int *rval_private_ptr;
234 tree *new_binfo_ptr, parent;
235 int protect, *via_virtual_ptr, via_virtual;
236 int current_scope_in_chain;
242 && !current_scope_in_chain
243 && is_friend (BINFO_TYPE (binfo), current_scope ()))
244 current_scope_in_chain = 1;
246 if (BINFO_TYPE (binfo) == parent || binfo == parent)
251 /* This is the first time we've found parent. */
253 else if (tree_int_cst_equal (BINFO_OFFSET (*new_binfo_ptr),
254 BINFO_OFFSET (binfo))
255 && *via_virtual_ptr && via_virtual)
257 /* A new path to the same vbase. If this one has better
258 access or is shorter, take it. */
261 better = *rval_private_ptr - is_private;
263 better = rval - depth;
267 /* Ambiguous base class. */
270 /* If we get an ambiguity between virtual and non-virtual base
271 class, return the non-virtual in case we are ignoring
273 better = *via_virtual_ptr - via_virtual;
279 *rval_private_ptr = is_private;
280 *new_binfo_ptr = binfo;
281 *via_virtual_ptr = via_virtual;
287 binfos = BINFO_BASETYPES (binfo);
288 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
291 /* Process base types. */
292 for (i = 0; i < n_baselinks; i++)
294 tree base_binfo = TREE_VEC_ELT (binfos, i);
299 || (!TREE_VIA_PUBLIC (base_binfo)
300 && !(TREE_VIA_PROTECTED (base_binfo)
301 && current_scope_in_chain)
302 && !is_friend (BINFO_TYPE (binfo), current_scope ()))))
304 && (is_private || !TREE_VIA_PUBLIC (base_binfo))));
306 int this_virtual = via_virtual || TREE_VIA_VIRTUAL (base_binfo);
308 rval = get_base_distance_recursive (base_binfo, depth, via_private,
309 rval, rval_private_ptr,
310 new_binfo_ptr, parent,
311 protect, via_virtual_ptr,
313 current_scope_in_chain);
315 /* If we've found a non-virtual, ambiguous base class, we don't need
316 to keep searching. */
317 if (rval == -2 && *via_virtual_ptr == 0)
324 /* Return the number of levels between type PARENT and the type given
325 in BINFO, following the leftmost path to PARENT not found along a
326 virtual path, if there are no real PARENTs (all come from virtual
327 base classes), then follow the shortest public path to PARENT.
329 Return -1 if TYPE is not derived from PARENT.
330 Return -2 if PARENT is an ambiguous base class of TYPE, and PROTECT is
332 Return -3 if PARENT is not accessible in TYPE, and PROTECT is non-zero.
334 If PATH_PTR is non-NULL, then also build the list of types
335 from PARENT to TYPE, with TREE_VIA_VIRTUAL and TREE_VIA_PUBLIC
338 If PROTECT is greater than 1, ignore any special access the current
339 scope might have when determining whether PARENT is inaccessible.
341 If BINFO is a binfo, its BINFO_INHERITANCE_CHAIN will be left alone. */
344 get_base_distance (parent, binfo, protect, path_ptr)
345 register tree parent, binfo;
350 int rval_private = 0;
351 tree type = NULL_TREE;
352 tree new_binfo = NULL_TREE;
354 int watch_access = protect;
356 /* Should we be completing types here? */
357 if (TREE_CODE (parent) != TREE_VEC)
358 parent = complete_type (TYPE_MAIN_VARIANT (parent));
360 complete_type (TREE_TYPE (parent));
362 if (TREE_CODE (binfo) == TREE_VEC)
363 type = BINFO_TYPE (binfo);
364 else if (IS_AGGR_TYPE_CODE (TREE_CODE (binfo)))
366 type = complete_type (binfo);
367 binfo = TYPE_BINFO (type);
370 my_friendly_assert (BINFO_INHERITANCE_CHAIN (binfo) == NULL_TREE,
374 my_friendly_abort (92);
376 if (parent == type || parent == binfo)
378 /* If the distance is 0, then we don't really need
379 a path pointer, but we shouldn't let garbage go back. */
385 if (path_ptr && watch_access == 0)
388 rval = get_base_distance_recursive (binfo, 0, 0, -1,
389 &rval_private, &new_binfo, parent,
390 watch_access, &via_virtual, 0,
393 /* Access restrictions don't count if we found an ambiguous basetype. */
394 if (rval == -2 && protect >= 0)
397 if (rval && protect && rval_private)
401 *path_ptr = new_binfo;
405 /* Worker for lookup_base. BINFO is the binfo we are searching at,
406 BASE is the RECORD_TYPE we are searching for. ACCESS is the
407 required access checks. WITHIN_CURRENT_SCOPE, IS_NON_PUBLIC and
408 IS_VIRTUAL indicate how BINFO was reached from the start of the
409 search. WITHIN_CURRENT_SCOPE is true if we met the current scope,
410 or friend thereof (this allows us to determine whether a protected
411 base is accessible or not). IS_NON_PUBLIC indicates whether BINFO
412 is accessible and IS_VIRTUAL indicates if it is morally virtual.
414 If BINFO is of the required type, then *BINFO_PTR is examined to
415 compare with any other instance of BASE we might have already
416 discovered. *BINFO_PTR is initialized and a base_kind return value
417 indicates what kind of base was located.
419 Otherwise BINFO's bases are searched. */
422 lookup_base_r (binfo, base, access, within_current_scope,
423 is_non_public, is_virtual, binfo_ptr)
426 int within_current_scope;
427 int is_non_public; /* inside a non-public part */
428 int is_virtual; /* inside a virtual part */
433 base_kind found = bk_not_base;
435 if (access == ba_check
436 && !within_current_scope
437 && is_friend (BINFO_TYPE (binfo), current_scope ()))
439 within_current_scope = 1;
443 if (same_type_p (BINFO_TYPE (binfo), base))
445 /* We have found a base. Check against what we have found
447 found = bk_same_type;
449 found = bk_via_virtual;
451 found = bk_inaccessible;
455 else if (!is_virtual || !tree_int_cst_equal (BINFO_OFFSET (binfo),
456 BINFO_OFFSET (*binfo_ptr)))
458 if (access != ba_any)
460 else if (found != is_virtual)
461 /* Prefer a non-virtual base. */
465 else if (found == bk_via_virtual)
471 bases = BINFO_BASETYPES (binfo);
475 for (i = TREE_VEC_LENGTH (bases); i--;)
477 tree base_binfo = TREE_VEC_ELT (bases, i);
478 int this_non_public = is_non_public;
479 int this_virtual = is_virtual;
481 if (access <= ba_ignore)
483 else if (TREE_VIA_PUBLIC (base_binfo))
485 else if (access == ba_not_special)
487 else if (TREE_VIA_PROTECTED (base_binfo) && within_current_scope)
489 else if (is_friend (BINFO_TYPE (binfo), current_scope ()))
494 if (TREE_VIA_VIRTUAL (base_binfo))
497 base_kind bk = lookup_base_r (base_binfo, base,
498 access, within_current_scope,
499 this_non_public, this_virtual,
505 if (access != ba_any)
510 case bk_inaccessible:
511 if (found == bk_not_base)
513 my_friendly_assert (found == bk_via_virtual
514 || found == bk_inaccessible, 20010723);
522 my_friendly_assert (found == bk_not_base, 20010723);
527 my_friendly_assert (found == bk_not_base
528 || found == bk_via_virtual
529 || found == bk_inaccessible, 20010723);
540 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
541 ACCESS specifies. Return the binfo we discover (which might not be
542 canonical). If KIND_PTR is non-NULL, fill with information about
543 what kind of base we discoveded.
545 Issue an error message if an inaccessible or ambiguous base is
546 discovered, and return error_mark_node. */
549 lookup_base (t, base, access, kind_ptr)
554 tree binfo = NULL; /* The binfo we've found so far. */
557 if (t == error_mark_node || base == error_mark_node)
560 *kind_ptr = bk_not_base;
561 return error_mark_node;
564 t = TYPE_MAIN_VARIANT (t);
565 base = TYPE_MAIN_VARIANT (base);
567 bk = lookup_base_r (TYPE_BINFO (t), base, access, 0, 0, 0, &binfo);
571 case bk_inaccessible:
572 cp_error ("`%T' is an inaccessible base of `%T'", base, t);
573 binfo = error_mark_node;
576 if (access != ba_any)
578 cp_error ("`%T' is an ambiguous base of `%T'", base, t);
579 binfo = error_mark_node;
592 /* Worker function for get_dynamic_cast_base_type. */
595 dynamic_cast_base_recurse (subtype, binfo, via_virtual, offset_ptr)
605 if (BINFO_TYPE (binfo) == subtype)
611 *offset_ptr = BINFO_OFFSET (binfo);
616 binfos = BINFO_BASETYPES (binfo);
617 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
618 for (i = 0; i < n_baselinks; i++)
620 tree base_binfo = TREE_VEC_ELT (binfos, i);
623 if (!TREE_VIA_PUBLIC (base_binfo))
625 rval = dynamic_cast_base_recurse
626 (subtype, base_binfo,
627 via_virtual || TREE_VIA_VIRTUAL (base_binfo), offset_ptr);
631 worst = worst >= 0 ? -3 : worst;
634 else if (rval == -3 && worst != -1)
640 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
641 started from is related to the required TARGET type, in order to optimize
642 the inheritance graph search. This information is independent of the
643 current context, and ignores private paths, hence get_base_distance is
644 inappropriate. Return a TREE specifying the base offset, BOFF.
645 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
646 and there are no public virtual SUBTYPE bases.
647 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
648 BOFF == -2, SUBTYPE is not a public base.
649 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
652 get_dynamic_cast_base_type (subtype, target)
656 tree offset = NULL_TREE;
657 int boff = dynamic_cast_base_recurse (subtype, TYPE_BINFO (target),
662 offset = build_int_2 (boff, -1);
663 TREE_TYPE (offset) = ssizetype;
667 /* Search for a member with name NAME in a multiple inheritance lattice
668 specified by TYPE. If it does not exist, return NULL_TREE.
669 If the member is ambiguously referenced, return `error_mark_node'.
670 Otherwise, return the FIELD_DECL. */
672 /* Do a 1-level search for NAME as a member of TYPE. The caller must
673 figure out whether it can access this field. (Since it is only one
674 level, this is reasonable.) */
677 lookup_field_1 (type, name)
682 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
683 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM
684 || TREE_CODE (type) == TYPENAME_TYPE)
685 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
686 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
687 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
688 the code often worked even when we treated the index as a list
690 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
694 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
695 && DECL_SORTED_FIELDS (TYPE_NAME (type)))
697 tree *fields = &TREE_VEC_ELT (DECL_SORTED_FIELDS (TYPE_NAME (type)), 0);
698 int lo = 0, hi = TREE_VEC_LENGTH (DECL_SORTED_FIELDS (TYPE_NAME (type)));
705 #ifdef GATHER_STATISTICS
707 #endif /* GATHER_STATISTICS */
709 if (DECL_NAME (fields[i]) > name)
711 else if (DECL_NAME (fields[i]) < name)
715 /* We might have a nested class and a field with the
716 same name; we sorted them appropriately via
717 field_decl_cmp, so just look for the last field with
720 && DECL_NAME (fields[i+1]) == name)
728 field = TYPE_FIELDS (type);
730 #ifdef GATHER_STATISTICS
731 n_calls_lookup_field_1++;
732 #endif /* GATHER_STATISTICS */
735 #ifdef GATHER_STATISTICS
737 #endif /* GATHER_STATISTICS */
738 my_friendly_assert (DECL_P (field), 0);
739 if (DECL_NAME (field) == NULL_TREE
740 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
742 tree temp = lookup_field_1 (TREE_TYPE (field), name);
746 if (TREE_CODE (field) == USING_DECL)
747 /* For now, we're just treating member using declarations as
748 old ARM-style access declarations. Thus, there's no reason
749 to return a USING_DECL, and the rest of the compiler can't
750 handle it. Once the class is defined, these are purged
751 from TYPE_FIELDS anyhow; see handle_using_decl. */
753 else if (DECL_NAME (field) == name)
755 if (TREE_CODE(field) == VAR_DECL
756 && (TREE_STATIC (field) || DECL_EXTERNAL (field)))
757 GNU_xref_ref(current_function_decl,
758 IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (field)));
761 field = TREE_CHAIN (field);
764 if (name == vptr_identifier)
766 /* Give the user what s/he thinks s/he wants. */
767 if (TYPE_POLYMORPHIC_P (type))
768 return TYPE_VFIELD (type);
773 /* There are a number of cases we need to be aware of here:
774 current_class_type current_function_decl
781 Those last two make life interesting. If we're in a function which is
782 itself inside a class, we need decls to go into the fn's decls (our
783 second case below). But if we're in a class and the class itself is
784 inside a function, we need decls to go into the decls for the class. To
785 achieve this last goal, we must see if, when both current_class_ptr and
786 current_function_decl are set, the class was declared inside that
787 function. If so, we know to put the decls into the class's scope. */
792 if (current_function_decl == NULL_TREE)
793 return current_class_type;
794 if (current_class_type == NULL_TREE)
795 return current_function_decl;
796 if ((DECL_FUNCTION_MEMBER_P (current_function_decl)
797 && same_type_p (DECL_CONTEXT (current_function_decl),
799 || (DECL_FRIEND_CONTEXT (current_function_decl)
800 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl),
801 current_class_type)))
802 return current_function_decl;
804 return current_class_type;
807 /* Returns non-zero if we are currently in a function scope. Note
808 that this function returns zero if we are within a local class, but
809 not within a member function body of the local class. */
812 at_function_scope_p ()
814 tree cs = current_scope ();
815 return cs && TREE_CODE (cs) == FUNCTION_DECL;
818 /* Return the scope of DECL, as appropriate when doing name-lookup. */
821 context_for_name_lookup (decl)
826 For the purposes of name lookup, after the anonymous union
827 definition, the members of the anonymous union are considered to
828 have been defined in the scope in which the anonymous union is
830 tree context = DECL_CONTEXT (decl);
832 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context))
833 context = TYPE_CONTEXT (context);
835 context = global_namespace;
840 /* Return a canonical BINFO if BINFO is a virtual base, or just BINFO
844 canonical_binfo (binfo)
847 return (TREE_VIA_VIRTUAL (binfo)
848 ? TYPE_BINFO (BINFO_TYPE (binfo)) : binfo);
851 /* A queue function that simply ensures that we walk into the
852 canonical versions of virtual bases. */
855 dfs_canonical_queue (binfo, data)
857 void *data ATTRIBUTE_UNUSED;
859 return canonical_binfo (binfo);
862 /* Called via dfs_walk from assert_canonical_unmarked. */
865 dfs_assert_unmarked_p (binfo, data)
867 void *data ATTRIBUTE_UNUSED;
869 my_friendly_assert (!BINFO_MARKED (binfo), 0);
873 /* Asserts that all the nodes below BINFO (using the canonical
874 versions of virtual bases) are unmarked. */
877 assert_canonical_unmarked (binfo)
880 dfs_walk (binfo, dfs_assert_unmarked_p, dfs_canonical_queue, 0);
883 /* If BINFO is marked, return a canonical version of BINFO.
884 Otherwise, return NULL_TREE. */
887 shared_marked_p (binfo, data)
891 binfo = canonical_binfo (binfo);
892 return markedp (binfo, data);
895 /* If BINFO is not marked, return a canonical version of BINFO.
896 Otherwise, return NULL_TREE. */
899 shared_unmarked_p (binfo, data)
903 binfo = canonical_binfo (binfo);
904 return unmarkedp (binfo, data);
907 /* The accessibility routines use BINFO_ACCESS for scratch space
908 during the computation of the accssibility of some declaration. */
910 #define BINFO_ACCESS(NODE) \
911 ((access_kind) ((TREE_LANG_FLAG_1 (NODE) << 1) | TREE_LANG_FLAG_6 (NODE)))
913 /* Set the access associated with NODE to ACCESS. */
915 #define SET_BINFO_ACCESS(NODE, ACCESS) \
916 ((TREE_LANG_FLAG_1 (NODE) = (ACCESS & 2) != 0), \
917 (TREE_LANG_FLAG_6 (NODE) = (ACCESS & 1) != 0))
919 /* Called from access_in_type via dfs_walk. Calculate the access to
920 DATA (which is really a DECL) in BINFO. */
923 dfs_access_in_type (binfo, data)
927 tree decl = (tree) data;
928 tree type = BINFO_TYPE (binfo);
929 access_kind access = ak_none;
931 if (context_for_name_lookup (decl) == type)
933 /* If we have desceneded to the scope of DECL, just note the
934 appropriate access. */
935 if (TREE_PRIVATE (decl))
937 else if (TREE_PROTECTED (decl))
938 access = ak_protected;
944 /* First, check for an access-declaration that gives us more
945 access to the DECL. The CONST_DECL for an enumeration
946 constant will not have DECL_LANG_SPECIFIC, and thus no
948 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl))
950 tree decl_access = purpose_member (type, DECL_ACCESS (decl));
952 access = ((access_kind)
953 TREE_INT_CST_LOW (TREE_VALUE (decl_access)));
962 /* Otherwise, scan our baseclasses, and pick the most favorable
964 binfos = BINFO_BASETYPES (binfo);
965 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
966 for (i = 0; i < n_baselinks; ++i)
968 tree base_binfo = TREE_VEC_ELT (binfos, i);
969 access_kind base_access
970 = BINFO_ACCESS (canonical_binfo (base_binfo));
972 if (base_access == ak_none || base_access == ak_private)
973 /* If it was not accessible in the base, or only
974 accessible as a private member, we can't access it
976 base_access = ak_none;
977 else if (TREE_VIA_PROTECTED (base_binfo))
978 /* Public and protected members in the base are
980 base_access = ak_protected;
981 else if (!TREE_VIA_PUBLIC (base_binfo))
982 /* Public and protected members in the base are
984 base_access = ak_private;
986 /* See if the new access, via this base, gives more
987 access than our previous best access. */
988 if (base_access != ak_none
989 && (base_access == ak_public
990 || (base_access == ak_protected
991 && access != ak_public)
992 || (base_access == ak_private
993 && access == ak_none)))
995 access = base_access;
997 /* If the new access is public, we can't do better. */
998 if (access == ak_public)
1005 /* Note the access to DECL in TYPE. */
1006 SET_BINFO_ACCESS (binfo, access);
1008 /* Mark TYPE as visited so that if we reach it again we do not
1009 duplicate our efforts here. */
1010 SET_BINFO_MARKED (binfo);
1015 /* Return the access to DECL in TYPE. */
1018 access_in_type (type, decl)
1022 tree binfo = TYPE_BINFO (type);
1024 /* We must take into account
1028 If a name can be reached by several paths through a multiple
1029 inheritance graph, the access is that of the path that gives
1032 The algorithm we use is to make a post-order depth-first traversal
1033 of the base-class hierarchy. As we come up the tree, we annotate
1034 each node with the most lenient access. */
1035 dfs_walk_real (binfo, 0, dfs_access_in_type, shared_unmarked_p, decl);
1036 dfs_walk (binfo, dfs_unmark, shared_marked_p, 0);
1037 assert_canonical_unmarked (binfo);
1039 return BINFO_ACCESS (binfo);
1042 /* Called from dfs_accessible_p via dfs_walk. */
1045 dfs_accessible_queue_p (binfo, data)
1047 void *data ATTRIBUTE_UNUSED;
1049 if (BINFO_MARKED (binfo))
1052 /* If this class is inherited via private or protected inheritance,
1053 then we can't see it, unless we are a friend of the subclass. */
1054 if (!TREE_VIA_PUBLIC (binfo)
1055 && !is_friend (BINFO_TYPE (BINFO_INHERITANCE_CHAIN (binfo)),
1059 return canonical_binfo (binfo);
1062 /* Called from dfs_accessible_p via dfs_walk. */
1065 dfs_accessible_p (binfo, data)
1069 int protected_ok = data != 0;
1072 SET_BINFO_MARKED (binfo);
1073 access = BINFO_ACCESS (binfo);
1074 if (access == ak_public || (access == ak_protected && protected_ok))
1076 else if (access != ak_none
1077 && is_friend (BINFO_TYPE (binfo), current_scope ()))
1083 /* Returns non-zero if it is OK to access DECL through an object
1084 indiated by BINFO in the context of DERIVED. */
1087 protected_accessible_p (decl, derived, binfo)
1094 /* We're checking this clause from [class.access.base]
1096 m as a member of N is protected, and the reference occurs in a
1097 member or friend of class N, or in a member or friend of a
1098 class P derived from N, where m as a member of P is private or
1101 Here DERIVED is a possible P and DECL is m. accessible_p will
1102 iterate over various values of N, but the access to m in DERIVED
1105 Note that I believe that the passage above is wrong, and should read
1106 "...is private or protected or public"; otherwise you get bizarre results
1107 whereby a public using-decl can prevent you from accessing a protected
1108 member of a base. (jason 2000/02/28) */
1110 /* If DERIVED isn't derived from m's class, then it can't be a P. */
1111 if (!DERIVED_FROM_P (context_for_name_lookup (decl), derived))
1114 access = access_in_type (derived, decl);
1116 /* If m is inaccessible in DERIVED, then it's not a P. */
1117 if (access == ak_none)
1120 /* [class.protected]
1122 When a friend or a member function of a derived class references
1123 a protected nonstatic member of a base class, an access check
1124 applies in addition to those described earlier in clause
1125 _class.access_) Except when forming a pointer to member
1126 (_expr.unary.op_), the access must be through a pointer to,
1127 reference to, or object of the derived class itself (or any class
1128 derived from that class) (_expr.ref_). If the access is to form
1129 a pointer to member, the nested-name-specifier shall name the
1130 derived class (or any class derived from that class). */
1131 if (DECL_NONSTATIC_MEMBER_P (decl))
1133 /* We can tell through what the reference is occurring by
1134 chasing BINFO up to the root. */
1136 while (BINFO_INHERITANCE_CHAIN (t))
1137 t = BINFO_INHERITANCE_CHAIN (t);
1139 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t)))
1146 /* Returns non-zero if SCOPE is a friend of a type which would be able
1147 to access DECL through the object indicated by BINFO. */
1150 friend_accessible_p (scope, decl, binfo)
1155 tree befriending_classes;
1161 if (TREE_CODE (scope) == FUNCTION_DECL
1162 || DECL_FUNCTION_TEMPLATE_P (scope))
1163 befriending_classes = DECL_BEFRIENDING_CLASSES (scope);
1164 else if (TYPE_P (scope))
1165 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope);
1169 for (t = befriending_classes; t; t = TREE_CHAIN (t))
1170 if (protected_accessible_p (decl, TREE_VALUE (t), binfo))
1173 /* Nested classes are implicitly friends of their enclosing types, as
1174 per core issue 45 (this is a change from the standard). */
1176 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t))
1177 if (protected_accessible_p (decl, t, binfo))
1180 if (TREE_CODE (scope) == FUNCTION_DECL
1181 || DECL_FUNCTION_TEMPLATE_P (scope))
1183 /* Perhaps this SCOPE is a member of a class which is a
1185 if (DECL_CLASS_SCOPE_P (decl)
1186 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo))
1189 /* Or an instantiation of something which is a friend. */
1190 if (DECL_TEMPLATE_INFO (scope))
1191 return friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo);
1193 else if (CLASSTYPE_TEMPLATE_INFO (scope))
1194 return friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope), decl, binfo);
1199 /* Perform access control on TYPE_DECL VAL, which was looked up in TYPE.
1200 This is fairly complex, so here's the design:
1202 The lang_extdef nonterminal sets type_lookups to NULL_TREE before we
1203 start to process a top-level declaration.
1204 As we process the decl-specifier-seq for the declaration, any types we
1205 see that might need access control are passed to type_access_control,
1206 which defers checking by adding them to type_lookups.
1207 When we are done with the decl-specifier-seq, we record the lookups we've
1208 seen in the lookups field of the typed_declspecs nonterminal.
1209 When we process the first declarator, either in parse_decl or
1210 begin_function_definition, we call save_type_access_control,
1211 which stores the lookups from the decl-specifier-seq in
1212 current_type_lookups.
1213 As we finish with each declarator, we process everything in type_lookups
1214 via decl_type_access_control, which resets type_lookups to the value of
1215 current_type_lookups for subsequent declarators.
1216 When we enter a function, we set type_lookups to error_mark_node, so all
1217 lookups are processed immediately. */
1220 type_access_control (type, val)
1223 if (val == NULL_TREE || TREE_CODE (val) != TYPE_DECL
1224 || ! DECL_CLASS_SCOPE_P (val))
1227 if (type_lookups == error_mark_node)
1228 enforce_access (type, val);
1229 else if (! accessible_p (type, val))
1230 type_lookups = tree_cons (type, val, type_lookups);
1233 /* DECL is a declaration from a base class of TYPE, which was the
1234 class used to name DECL. Return non-zero if, in the current
1235 context, DECL is accessible. If TYPE is actually a BINFO node,
1236 then we can tell in what context the access is occurring by looking
1237 at the most derived class along the path indicated by BINFO. */
1240 accessible_p (type, decl)
1248 /* Non-zero if it's OK to access DECL if it has protected
1249 accessibility in TYPE. */
1250 int protected_ok = 0;
1252 /* If we're not checking access, everything is accessible. */
1253 if (!flag_access_control)
1256 /* If this declaration is in a block or namespace scope, there's no
1258 if (!TYPE_P (context_for_name_lookup (decl)))
1264 type = BINFO_TYPE (type);
1267 binfo = TYPE_BINFO (type);
1269 /* [class.access.base]
1271 A member m is accessible when named in class N if
1273 --m as a member of N is public, or
1275 --m as a member of N is private, and the reference occurs in a
1276 member or friend of class N, or
1278 --m as a member of N is protected, and the reference occurs in a
1279 member or friend of class N, or in a member or friend of a
1280 class P derived from N, where m as a member of P is private or
1283 --there exists a base class B of N that is accessible at the point
1284 of reference, and m is accessible when named in class B.
1286 We walk the base class hierarchy, checking these conditions. */
1288 /* Figure out where the reference is occurring. Check to see if
1289 DECL is private or protected in this scope, since that will
1290 determine whether protected access is allowed. */
1291 if (current_class_type)
1292 protected_ok = protected_accessible_p (decl, current_class_type, binfo);
1294 /* Now, loop through the classes of which we are a friend. */
1296 protected_ok = friend_accessible_p (current_scope (), decl, binfo);
1298 /* Standardize the binfo that access_in_type will use. We don't
1299 need to know what path was chosen from this point onwards. */
1300 binfo = TYPE_BINFO (type);
1302 /* Compute the accessibility of DECL in the class hierarchy
1303 dominated by type. */
1304 access_in_type (type, decl);
1305 /* Walk the hierarchy again, looking for a base class that allows
1307 t = dfs_walk (binfo, dfs_accessible_p,
1308 dfs_accessible_queue_p,
1309 protected_ok ? &protected_ok : 0);
1310 /* Clear any mark bits. Note that we have to walk the whole tree
1311 here, since we have aborted the previous walk from some point
1312 deep in the tree. */
1313 dfs_walk (binfo, dfs_unmark, dfs_canonical_queue, 0);
1314 assert_canonical_unmarked (binfo);
1316 return t != NULL_TREE;
1319 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1320 found as a base class and sub-object of the object denoted by
1321 BINFO. MOST_DERIVED is the most derived type of the hierarchy being
1325 is_subobject_of_p (parent, binfo, most_derived)
1326 tree parent, binfo, most_derived;
1331 if (parent == binfo)
1334 binfos = BINFO_BASETYPES (binfo);
1335 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos) : 0;
1337 /* Iterate the base types. */
1338 for (i = 0; i < n_baselinks; i++)
1340 tree base_binfo = TREE_VEC_ELT (binfos, i);
1341 if (!CLASS_TYPE_P (TREE_TYPE (base_binfo)))
1342 /* If we see a TEMPLATE_TYPE_PARM, or some such, as a base
1343 class there's no way to descend into it. */
1346 if (is_subobject_of_p (parent,
1347 CANONICAL_BINFO (base_binfo, most_derived),
1354 struct lookup_field_info {
1355 /* The type in which we're looking. */
1357 /* The name of the field for which we're looking. */
1359 /* If non-NULL, the current result of the lookup. */
1361 /* The path to RVAL. */
1363 /* If non-NULL, the lookup was ambiguous, and this is a list of the
1366 /* If non-zero, we are looking for types, not data members. */
1368 /* If non-zero, RVAL was found by looking through a dependent base. */
1369 int from_dep_base_p;
1370 /* If something went wrong, a message indicating what. */
1374 /* Returns non-zero if BINFO is not hidden by the value found by the
1375 lookup so far. If BINFO is hidden, then there's no need to look in
1376 it. DATA is really a struct lookup_field_info. Called from
1377 lookup_field via breadth_first_search. */
1380 lookup_field_queue_p (binfo, data)
1384 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1386 /* Don't look for constructors or destructors in base classes. */
1387 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
1390 /* If this base class is hidden by the best-known value so far, we
1391 don't need to look. */
1392 if (!lfi->from_dep_base_p && lfi->rval_binfo
1393 && is_subobject_of_p (binfo, lfi->rval_binfo, lfi->type))
1396 return CANONICAL_BINFO (binfo, lfi->type);
1399 /* Within the scope of a template class, you can refer to the to the
1400 current specialization with the name of the template itself. For
1403 template <typename T> struct S { S* sp; }
1405 Returns non-zero if DECL is such a declaration in a class TYPE. */
1408 template_self_reference_p (type, decl)
1412 return (CLASSTYPE_USE_TEMPLATE (type)
1413 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
1414 && TREE_CODE (decl) == TYPE_DECL
1415 && DECL_ARTIFICIAL (decl)
1416 && DECL_NAME (decl) == constructor_name (type));
1420 /* Nonzero for a class member means that it is shared between all objects
1423 [class.member.lookup]:If the resulting set of declarations are not all
1424 from sub-objects of the same type, or the set has a nonstatic member
1425 and includes members from distinct sub-objects, there is an ambiguity
1426 and the program is ill-formed.
1428 This function checks that T contains no nonstatic members. */
1434 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \
1435 || TREE_CODE (t) == CONST_DECL)
1437 if (is_overloaded_fn (t))
1439 for (; t; t = OVL_NEXT (t))
1441 tree fn = OVL_CURRENT (t);
1442 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
1450 /* DATA is really a struct lookup_field_info. Look for a field with
1451 the name indicated there in BINFO. If this function returns a
1452 non-NULL value it is the result of the lookup. Called from
1453 lookup_field via breadth_first_search. */
1456 lookup_field_r (binfo, data)
1460 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1461 tree type = BINFO_TYPE (binfo);
1462 tree nval = NULL_TREE;
1463 int from_dep_base_p;
1465 /* First, look for a function. There can't be a function and a data
1466 member with the same name, and if there's a function and a type
1467 with the same name, the type is hidden by the function. */
1468 if (!lfi->want_type)
1470 int idx = lookup_fnfields_1 (type, lfi->name);
1472 nval = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), idx);
1476 /* Look for a data member or type. */
1477 nval = lookup_field_1 (type, lfi->name);
1479 /* If there is no declaration with the indicated name in this type,
1480 then there's nothing to do. */
1484 /* If we're looking up a type (as with an elaborated type specifier)
1485 we ignore all non-types we find. */
1486 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL
1487 && !DECL_CLASS_TEMPLATE_P (nval))
1489 if (lfi->name == TYPE_IDENTIFIER (type))
1491 /* If the aggregate has no user defined constructors, we allow
1492 it to have fields with the same name as the enclosing type.
1493 If we are looking for that name, find the corresponding
1495 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval))
1496 if (DECL_NAME (nval) == lfi->name
1497 && TREE_CODE (nval) == TYPE_DECL)
1504 nval = purpose_member (lfi->name, CLASSTYPE_TAGS (type));
1506 nval = TYPE_MAIN_DECL (TREE_VALUE (nval));
1512 /* You must name a template base class with a template-id. */
1513 if (!same_type_p (type, lfi->type)
1514 && template_self_reference_p (type, nval))
1517 from_dep_base_p = dependent_base_p (binfo);
1518 if (lfi->from_dep_base_p && !from_dep_base_p)
1520 /* If the new declaration is not found via a dependent base, and
1521 the old one was, then we must prefer the new one. We weren't
1522 really supposed to be able to find the old one, so we don't
1523 want to be affected by a specialization. Consider:
1525 struct B { typedef int I; };
1526 template <typename T> struct D1 : virtual public B {};
1527 template <typename T> struct D :
1528 public D1, virtual pubic B { I i; };
1530 The `I' in `D<T>' is unambigousuly `B::I', regardless of how
1531 D1 is specialized. */
1532 lfi->from_dep_base_p = 0;
1533 lfi->rval = NULL_TREE;
1534 lfi->rval_binfo = NULL_TREE;
1535 lfi->ambiguous = NULL_TREE;
1538 else if (lfi->rval_binfo && !lfi->from_dep_base_p && from_dep_base_p)
1539 /* Similarly, if the old declaration was not found via a dependent
1540 base, and the new one is, ignore the new one. */
1543 /* If the lookup already found a match, and the new value doesn't
1544 hide the old one, we might have an ambiguity. */
1545 if (lfi->rval_binfo && !is_subobject_of_p (lfi->rval_binfo, binfo, lfi->type))
1547 if (nval == lfi->rval && shared_member_p (nval))
1548 /* The two things are really the same. */
1550 else if (is_subobject_of_p (binfo, lfi->rval_binfo, lfi->type))
1551 /* The previous value hides the new one. */
1555 /* We have a real ambiguity. We keep a chain of all the
1557 if (!lfi->ambiguous && lfi->rval)
1559 /* This is the first time we noticed an ambiguity. Add
1560 what we previously thought was a reasonable candidate
1562 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE);
1563 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1566 /* Add the new value. */
1567 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous);
1568 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1569 lfi->errstr = "request for member `%D' is ambiguous";
1574 if (from_dep_base_p && TREE_CODE (nval) != TYPE_DECL
1575 /* We need to return a member template class so we can
1576 define partial specializations. Is there a better
1578 && !DECL_CLASS_TEMPLATE_P (nval))
1579 /* The thing we're looking for isn't a type, so the implicit
1580 typename extension doesn't apply, so we just pretend we
1581 didn't find anything. */
1585 lfi->from_dep_base_p = from_dep_base_p;
1586 lfi->rval_binfo = binfo;
1592 /* Look for a member named NAME in an inheritance lattice dominated by
1593 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it is
1594 1, we enforce accessibility. If PROTECT is zero, then, for an
1595 ambiguous lookup, we return NULL. If PROTECT is 1, we issue an
1596 error message. If PROTECT is 2, we return a TREE_LIST whose
1597 TREE_TYPE is error_mark_node and whose TREE_VALUEs are the list of
1598 ambiguous candidates.
1600 WANT_TYPE is 1 when we should only return TYPE_DECLs, if no
1601 TYPE_DECL can be found return NULL_TREE. */
1604 lookup_member (xbasetype, name, protect, want_type)
1605 register tree xbasetype, name;
1606 int protect, want_type;
1608 tree rval, rval_binfo = NULL_TREE;
1609 tree type = NULL_TREE, basetype_path = NULL_TREE;
1610 struct lookup_field_info lfi;
1612 /* rval_binfo is the binfo associated with the found member, note,
1613 this can be set with useful information, even when rval is not
1614 set, because it must deal with ALL members, not just non-function
1615 members. It is used for ambiguity checking and the hidden
1616 checks. Whereas rval is only set if a proper (not hidden)
1617 non-function member is found. */
1619 const char *errstr = 0;
1621 if (xbasetype == current_class_type && TYPE_BEING_DEFINED (xbasetype)
1622 && IDENTIFIER_CLASS_VALUE (name))
1624 tree field = IDENTIFIER_CLASS_VALUE (name);
1625 if (TREE_CODE (field) != FUNCTION_DECL
1626 && ! (want_type && TREE_CODE (field) != TYPE_DECL))
1627 /* We're in the scope of this class, and the value has already
1628 been looked up. Just return the cached value. */
1632 if (TREE_CODE (xbasetype) == TREE_VEC)
1634 type = BINFO_TYPE (xbasetype);
1635 basetype_path = xbasetype;
1637 else if (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype)))
1640 basetype_path = TYPE_BINFO (type);
1641 my_friendly_assert (BINFO_INHERITANCE_CHAIN (basetype_path) == NULL_TREE,
1645 my_friendly_abort (97);
1647 complete_type (type);
1649 #ifdef GATHER_STATISTICS
1650 n_calls_lookup_field++;
1651 #endif /* GATHER_STATISTICS */
1653 memset ((PTR) &lfi, 0, sizeof (lfi));
1656 lfi.want_type = want_type;
1657 bfs_walk (basetype_path, &lookup_field_r, &lookup_field_queue_p, &lfi);
1659 rval_binfo = lfi.rval_binfo;
1661 type = BINFO_TYPE (rval_binfo);
1662 errstr = lfi.errstr;
1664 /* If we are not interested in ambiguities, don't report them;
1665 just return NULL_TREE. */
1666 if (!protect && lfi.ambiguous)
1672 return lfi.ambiguous;
1679 In the case of overloaded function names, access control is
1680 applied to the function selected by overloaded resolution. */
1681 if (rval && protect && !is_overloaded_fn (rval)
1682 && !enforce_access (xbasetype, rval))
1683 return error_mark_node;
1685 if (errstr && protect)
1687 cp_error (errstr, name, type);
1689 print_candidates (lfi.ambiguous);
1690 rval = error_mark_node;
1693 /* If the thing we found was found via the implicit typename
1694 extension, build the typename type. */
1695 if (rval && lfi.from_dep_base_p && !DECL_CLASS_TEMPLATE_P (rval))
1696 rval = TYPE_STUB_DECL (build_typename_type (BINFO_TYPE (basetype_path),
1700 if (rval && is_overloaded_fn (rval))
1702 /* Note that the binfo we put in the baselink is the binfo where
1703 we found the functions, which we need for overload
1704 resolution, but which should not be passed to enforce_access;
1705 rather, enforce_access wants a binfo which refers to the
1706 scope in which we started looking for the function. This
1707 will generally be the binfo passed into this function as
1710 rval = tree_cons (rval_binfo, rval, NULL_TREE);
1711 SET_BASELINK_P (rval);
1717 /* Like lookup_member, except that if we find a function member we
1718 return NULL_TREE. */
1721 lookup_field (xbasetype, name, protect, want_type)
1722 register tree xbasetype, name;
1723 int protect, want_type;
1725 tree rval = lookup_member (xbasetype, name, protect, want_type);
1727 /* Ignore functions. */
1728 if (rval && TREE_CODE (rval) == TREE_LIST)
1734 /* Like lookup_member, except that if we find a non-function member we
1735 return NULL_TREE. */
1738 lookup_fnfields (xbasetype, name, protect)
1739 register tree xbasetype, name;
1742 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/0);
1744 /* Ignore non-functions. */
1745 if (rval && TREE_CODE (rval) != TREE_LIST)
1751 /* TYPE is a class type. Return the index of the fields within
1752 the method vector with name NAME, or -1 is no such field exists. */
1755 lookup_fnfields_1 (type, name)
1759 = CLASS_TYPE_P (type) ? CLASSTYPE_METHOD_VEC (type) : NULL_TREE;
1761 if (method_vec != 0)
1764 register tree *methods = &TREE_VEC_ELT (method_vec, 0);
1765 int len = TREE_VEC_LENGTH (method_vec);
1768 #ifdef GATHER_STATISTICS
1769 n_calls_lookup_fnfields_1++;
1770 #endif /* GATHER_STATISTICS */
1772 /* Constructors are first... */
1773 if (name == ctor_identifier)
1774 return (methods[CLASSTYPE_CONSTRUCTOR_SLOT]
1775 ? CLASSTYPE_CONSTRUCTOR_SLOT : -1);
1776 /* and destructors are second. */
1777 if (name == dtor_identifier)
1778 return (methods[CLASSTYPE_DESTRUCTOR_SLOT]
1779 ? CLASSTYPE_DESTRUCTOR_SLOT : -1);
1781 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1782 i < len && methods[i];
1785 #ifdef GATHER_STATISTICS
1786 n_outer_fields_searched++;
1787 #endif /* GATHER_STATISTICS */
1789 tmp = OVL_CURRENT (methods[i]);
1790 if (DECL_NAME (tmp) == name)
1793 /* If the type is complete and we're past the conversion ops,
1794 switch to binary search. */
1795 if (! DECL_CONV_FN_P (tmp)
1796 && COMPLETE_TYPE_P (type))
1798 int lo = i + 1, hi = len;
1804 #ifdef GATHER_STATISTICS
1805 n_outer_fields_searched++;
1806 #endif /* GATHER_STATISTICS */
1808 tmp = DECL_NAME (OVL_CURRENT (methods[i]));
1812 else if (tmp < name)
1821 /* If we didn't find it, it might have been a template
1822 conversion operator. (Note that we don't look for this case
1823 above so that we will always find specializations first.) */
1824 if (IDENTIFIER_TYPENAME_P (name))
1826 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1827 i < len && methods[i];
1830 tmp = OVL_CURRENT (methods[i]);
1831 if (! DECL_CONV_FN_P (tmp))
1833 /* Since all conversion operators come first, we know
1834 there is no such operator. */
1837 else if (TREE_CODE (tmp) == TEMPLATE_DECL)
1846 /* Walk the class hierarchy dominated by TYPE. FN is called for each
1847 type in the hierarchy, in a breadth-first preorder traversal.
1848 If it ever returns a non-NULL value, that value is immediately
1849 returned and the walk is terminated. At each node, FN is passed a
1850 BINFO indicating the path from the curently visited base-class to
1851 TYPE. Before each base-class is walked QFN is called. If the
1852 value returned is non-zero, the base-class is walked; otherwise it
1853 is not. If QFN is NULL, it is treated as a function which always
1854 returns 1. Both FN and QFN are passed the DATA whenever they are
1858 bfs_walk (binfo, fn, qfn, data)
1860 tree (*fn) PARAMS ((tree, void *));
1861 tree (*qfn) PARAMS ((tree, void *));
1866 tree rval = NULL_TREE;
1867 /* An array of the base classes of BINFO. These will be built up in
1868 breadth-first order, except where QFN prunes the search. */
1869 varray_type bfs_bases;
1871 /* Start with enough room for ten base classes. That will be enough
1872 for most hierarchies. */
1873 VARRAY_TREE_INIT (bfs_bases, 10, "search_stack");
1875 /* Put the first type into the stack. */
1876 VARRAY_TREE (bfs_bases, 0) = binfo;
1879 for (head = 0; head < tail; ++head)
1885 /* Pull the next type out of the queue. */
1886 binfo = VARRAY_TREE (bfs_bases, head);
1888 /* If this is the one we're looking for, we're done. */
1889 rval = (*fn) (binfo, data);
1893 /* Queue up the base types. */
1894 binfos = BINFO_BASETYPES (binfo);
1895 n_baselinks = binfos ? TREE_VEC_LENGTH (binfos): 0;
1896 for (i = 0; i < n_baselinks; i++)
1898 tree base_binfo = TREE_VEC_ELT (binfos, i);
1901 base_binfo = (*qfn) (base_binfo, data);
1905 if (tail == VARRAY_SIZE (bfs_bases))
1906 VARRAY_GROW (bfs_bases, 2 * VARRAY_SIZE (bfs_bases));
1907 VARRAY_TREE (bfs_bases, tail) = base_binfo;
1914 VARRAY_FREE (bfs_bases);
1919 /* Exactly like bfs_walk, except that a depth-first traversal is
1920 performed, and PREFN is called in preorder, while POSTFN is called
1924 dfs_walk_real (binfo, prefn, postfn, qfn, data)
1926 tree (*prefn) PARAMS ((tree, void *));
1927 tree (*postfn) PARAMS ((tree, void *));
1928 tree (*qfn) PARAMS ((tree, void *));
1934 tree rval = NULL_TREE;
1936 /* Call the pre-order walking function. */
1939 rval = (*prefn) (binfo, data);
1944 /* Process the basetypes. */
1945 binfos = BINFO_BASETYPES (binfo);
1946 n_baselinks = BINFO_N_BASETYPES (binfo);
1947 for (i = 0; i < n_baselinks; i++)
1949 tree base_binfo = TREE_VEC_ELT (binfos, i);
1952 base_binfo = (*qfn) (base_binfo, data);
1956 rval = dfs_walk_real (base_binfo, prefn, postfn, qfn, data);
1962 /* Call the post-order walking function. */
1964 rval = (*postfn) (binfo, data);
1969 /* Exactly like bfs_walk, except that a depth-first post-order traversal is
1973 dfs_walk (binfo, fn, qfn, data)
1975 tree (*fn) PARAMS ((tree, void *));
1976 tree (*qfn) PARAMS ((tree, void *));
1979 return dfs_walk_real (binfo, 0, fn, qfn, data);
1982 /* Returns > 0 if a function with type DRETTYPE overriding a function
1983 with type BRETTYPE is covariant, as defined in [class.virtual].
1985 Returns 1 if trivial covariance, 2 if non-trivial (requiring runtime
1986 adjustment), or -1 if pedantically invalid covariance. */
1989 covariant_return_p (brettype, drettype)
1990 tree brettype, drettype;
1994 if (TREE_CODE (brettype) == FUNCTION_DECL)
1996 brettype = TREE_TYPE (TREE_TYPE (brettype));
1997 drettype = TREE_TYPE (TREE_TYPE (drettype));
1999 else if (TREE_CODE (brettype) == METHOD_TYPE)
2001 brettype = TREE_TYPE (brettype);
2002 drettype = TREE_TYPE (drettype);
2005 if (same_type_p (brettype, drettype))
2008 if (! (TREE_CODE (brettype) == TREE_CODE (drettype)
2009 && (TREE_CODE (brettype) == POINTER_TYPE
2010 || TREE_CODE (brettype) == REFERENCE_TYPE)
2011 && TYPE_QUALS (brettype) == TYPE_QUALS (drettype)))
2014 if (! can_convert (brettype, drettype))
2017 brettype = TREE_TYPE (brettype);
2018 drettype = TREE_TYPE (drettype);
2020 /* If not pedantic, allow any standard pointer conversion. */
2021 if (! IS_AGGR_TYPE (drettype) || ! IS_AGGR_TYPE (brettype))
2024 binfo = get_binfo (brettype, drettype, 1);
2026 /* If we get an error_mark_node from get_binfo, it already complained,
2027 so let's just succeed. */
2028 if (binfo == error_mark_node)
2031 if (! BINFO_OFFSET_ZEROP (binfo) || TREE_VIA_VIRTUAL (binfo))
2036 /* Check that virtual overrider OVERRIDER is acceptable for base function
2037 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
2040 check_final_overrider (overrider, basefn)
2041 tree overrider, basefn;
2043 tree over_type = TREE_TYPE (overrider);
2044 tree base_type = TREE_TYPE (basefn);
2045 tree over_return = TREE_TYPE (over_type);
2046 tree base_return = TREE_TYPE (base_type);
2047 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type);
2048 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type);
2051 if (same_type_p (base_return, over_return))
2053 else if ((i = covariant_return_p (base_return, over_return)))
2056 sorry ("adjusting pointers for covariant returns");
2058 if (pedantic && i == -1)
2060 cp_pedwarn_at ("invalid covariant return type for `%#D'", overrider);
2061 cp_pedwarn_at (" overriding `%#D' (must be pointer or reference to class)", basefn);
2064 else if (IS_AGGR_TYPE_2 (base_return, over_return)
2065 && same_or_base_type_p (base_return, over_return))
2067 cp_error_at ("invalid covariant return type for `%#D'", overrider);
2068 cp_error_at (" overriding `%#D' (must use pointer or reference)", basefn);
2071 else if (IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider)) == NULL_TREE)
2073 cp_error_at ("conflicting return type specified for `%#D'", overrider);
2074 cp_error_at (" overriding `%#D'", basefn);
2075 SET_IDENTIFIER_ERROR_LOCUS (DECL_ASSEMBLER_NAME (overrider),
2076 DECL_CONTEXT (overrider));
2080 /* Check throw specifier is subset. */
2081 if (!comp_except_specs (base_throw, over_throw, 0))
2083 cp_error_at ("looser throw specifier for `%#F'", overrider);
2084 cp_error_at (" overriding `%#F'", basefn);
2090 /* Given a class TYPE, and a function decl FNDECL, look for
2091 virtual functions in TYPE's hierarchy which FNDECL overrides.
2092 We do not look in TYPE itself, only its bases.
2094 Returns non-zero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
2095 find that it overrides anything.
2097 We check that every function which is overridden, is correctly
2101 look_for_overrides (type, fndecl)
2104 tree binfo = TYPE_BINFO (type);
2105 tree basebinfos = BINFO_BASETYPES (binfo);
2106 int nbasebinfos = basebinfos ? TREE_VEC_LENGTH (basebinfos) : 0;
2110 for (ix = 0; ix != nbasebinfos; ix++)
2112 tree basetype = BINFO_TYPE (TREE_VEC_ELT (basebinfos, ix));
2114 if (TYPE_POLYMORPHIC_P (basetype))
2115 found += look_for_overrides_r (basetype, fndecl);
2120 /* Look in TYPE for virtual functions with the same signature as FNDECL.
2121 This differs from get_matching_virtual in that it will only return
2122 a function from TYPE. */
2125 look_for_overrides_here (type, fndecl)
2130 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl))
2131 ix = CLASSTYPE_DESTRUCTOR_SLOT;
2133 ix = lookup_fnfields_1 (type, DECL_NAME (fndecl));
2136 tree fns = TREE_VEC_ELT (CLASSTYPE_METHOD_VEC (type), ix);
2138 for (; fns; fns = OVL_NEXT (fns))
2140 tree fn = OVL_CURRENT (fns);
2142 if (!DECL_VIRTUAL_P (fn))
2143 /* Not a virtual. */;
2144 else if (DECL_CONTEXT (fn) != type)
2145 /* Introduced with a using declaration. */;
2146 else if (DECL_STATIC_FUNCTION_P (fndecl))
2148 tree btypes = TYPE_ARG_TYPES (TREE_TYPE (fn));
2149 tree dtypes = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
2150 if (compparms (TREE_CHAIN (btypes), dtypes))
2153 else if (same_signature_p (fndecl, fn))
2160 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
2161 TYPE itself and its bases. */
2164 look_for_overrides_r (type, fndecl)
2167 tree fn = look_for_overrides_here (type, fndecl);
2170 if (DECL_STATIC_FUNCTION_P (fndecl))
2172 /* A static member function cannot match an inherited
2173 virtual member function. */
2174 cp_error_at ("`%#D' cannot be declared", fndecl);
2175 cp_error_at (" since `%#D' declared in base class", fn);
2179 /* It's definitely virtual, even if not explicitly set. */
2180 DECL_VIRTUAL_P (fndecl) = 1;
2181 check_final_overrider (fndecl, fn);
2186 /* We failed to find one declared in this class. Look in its bases. */
2187 return look_for_overrides (type, fndecl);
2190 /* A queue function for dfs_walk that skips any nonprimary virtual
2191 bases and any already marked bases. */
2194 dfs_skip_nonprimary_vbases_unmarkedp (binfo, data)
2196 void *data ATTRIBUTE_UNUSED;
2198 if (TREE_VIA_VIRTUAL (binfo) && !BINFO_PRIMARY_P (binfo))
2199 /* This is a non-primary virtual base. Skip it. */
2202 return unmarkedp (binfo, NULL);
2205 /* A queue function for dfs_walk that skips any nonprimary virtual
2206 bases and any unmarked bases. */
2209 dfs_skip_nonprimary_vbases_markedp (binfo, data)
2211 void *data ATTRIBUTE_UNUSED;
2213 if (TREE_VIA_VIRTUAL (binfo) && !BINFO_PRIMARY_P (binfo))
2214 /* This is a non-primary virtual base. Skip it. */
2217 return markedp (binfo, NULL);
2220 /* If BINFO is a non-primary virtual baseclass (in the hierarchy
2221 dominated by TYPE), and no primary copy appears anywhere in the
2222 hierarchy, return the shared copy. If a primary copy appears
2223 elsewhere, return NULL_TREE. Otherwise, return BINFO itself; it is
2224 either a non-virtual base or a primary virtual base. */
2227 get_shared_vbase_if_not_primary (binfo, data)
2231 if (TREE_VIA_VIRTUAL (binfo) && !BINFO_PRIMARY_P (binfo))
2233 tree type = (tree) data;
2235 if (TREE_CODE (type) == TREE_LIST)
2236 type = TREE_PURPOSE (type);
2238 /* This is a non-primary virtual base. If there is no primary
2239 version, get the shared version. */
2240 binfo = binfo_for_vbase (BINFO_TYPE (binfo), type);
2241 if (BINFO_PRIMARY_P (binfo))
2248 /* A queue function to use with dfs_walk that prevents travel into any
2249 nonprimary virtual base, or its baseclasses. DATA should be the
2250 type of the complete object, or a TREE_LIST whose TREE_PURPOSE is
2251 the type of the complete object. By using this function as a queue
2252 function, you will walk over exactly those BINFOs that actually
2253 exist in the complete object, including those for virtual base
2254 classes. If you SET_BINFO_MARKED for each binfo you process, you
2255 are further guaranteed that you will walk into each virtual base
2256 class exactly once. */
2259 dfs_unmarked_real_bases_queue_p (binfo, data)
2263 binfo = get_shared_vbase_if_not_primary (binfo, data);
2264 return binfo ? unmarkedp (binfo, NULL) : NULL_TREE;
2267 /* Like dfs_unmarked_real_bases_queue_p but walks only into things
2268 that are marked, rather than unmarked. */
2271 dfs_marked_real_bases_queue_p (binfo, data)
2275 binfo = get_shared_vbase_if_not_primary (binfo, data);
2276 return binfo ? markedp (binfo, NULL) : NULL_TREE;
2279 /* A queue function that skips all virtual bases (and their
2283 dfs_skip_vbases (binfo, data)
2285 void *data ATTRIBUTE_UNUSED;
2287 if (TREE_VIA_VIRTUAL (binfo))
2293 /* Called via dfs_walk from dfs_get_pure_virtuals. */
2296 dfs_get_pure_virtuals (binfo, data)
2300 tree type = (tree) data;
2302 /* We're not interested in primary base classes; the derived class
2303 of which they are a primary base will contain the information we
2305 if (!BINFO_PRIMARY_P (binfo))
2309 for (virtuals = BINFO_VIRTUALS (binfo);
2311 virtuals = TREE_CHAIN (virtuals))
2312 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals)))
2313 CLASSTYPE_PURE_VIRTUALS (type)
2314 = tree_cons (NULL_TREE, BV_FN (virtuals),
2315 CLASSTYPE_PURE_VIRTUALS (type));
2318 SET_BINFO_MARKED (binfo);
2323 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
2326 get_pure_virtuals (type)
2331 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
2332 is going to be overridden. */
2333 CLASSTYPE_PURE_VIRTUALS (type) = NULL_TREE;
2334 /* Now, run through all the bases which are not primary bases, and
2335 collect the pure virtual functions. We look at the vtable in
2336 each class to determine what pure virtual functions are present.
2337 (A primary base is not interesting because the derived class of
2338 which it is a primary base will contain vtable entries for the
2339 pure virtuals in the base class. */
2340 dfs_walk (TYPE_BINFO (type), dfs_get_pure_virtuals,
2341 dfs_unmarked_real_bases_queue_p, type);
2342 dfs_walk (TYPE_BINFO (type), dfs_unmark,
2343 dfs_marked_real_bases_queue_p, type);
2345 /* Put the pure virtuals in dfs order. */
2346 CLASSTYPE_PURE_VIRTUALS (type) = nreverse (CLASSTYPE_PURE_VIRTUALS (type));
2348 for (vbases = CLASSTYPE_VBASECLASSES (type);
2350 vbases = TREE_CHAIN (vbases))
2354 for (virtuals = BINFO_VIRTUALS (TREE_VALUE (vbases));
2356 virtuals = TREE_CHAIN (virtuals))
2358 tree base_fndecl = BV_FN (virtuals);
2359 if (DECL_NEEDS_FINAL_OVERRIDER_P (base_fndecl))
2360 cp_error ("`%#D' needs a final overrider", base_fndecl);
2365 /* DEPTH-FIRST SEARCH ROUTINES. */
2368 markedp (binfo, data)
2370 void *data ATTRIBUTE_UNUSED;
2372 return BINFO_MARKED (binfo) ? binfo : NULL_TREE;
2376 unmarkedp (binfo, data)
2378 void *data ATTRIBUTE_UNUSED;
2380 return !BINFO_MARKED (binfo) ? binfo : NULL_TREE;
2384 marked_vtable_pathp (binfo, data)
2386 void *data ATTRIBUTE_UNUSED;
2388 return BINFO_VTABLE_PATH_MARKED (binfo) ? binfo : NULL_TREE;
2392 unmarked_vtable_pathp (binfo, data)
2394 void *data ATTRIBUTE_UNUSED;
2396 return !BINFO_VTABLE_PATH_MARKED (binfo) ? binfo : NULL_TREE;
2400 marked_pushdecls_p (binfo, data)
2402 void *data ATTRIBUTE_UNUSED;
2404 return (CLASS_TYPE_P (BINFO_TYPE (binfo))
2405 && BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
2409 unmarked_pushdecls_p (binfo, data)
2411 void *data ATTRIBUTE_UNUSED;
2413 return (CLASS_TYPE_P (BINFO_TYPE (binfo))
2414 && !BINFO_PUSHDECLS_MARKED (binfo)) ? binfo : NULL_TREE;
2417 /* The worker functions for `dfs_walk'. These do not need to
2418 test anything (vis a vis marking) if they are paired with
2419 a predicate function (above). */
2422 dfs_unmark (binfo, data)
2424 void *data ATTRIBUTE_UNUSED;
2426 CLEAR_BINFO_MARKED (binfo);
2430 /* get virtual base class types.
2431 This adds type to the vbase_types list in reverse dfs order.
2432 Ordering is very important, so don't change it. */
2435 dfs_get_vbase_types (binfo, data)
2439 tree type = (tree) data;
2441 if (TREE_VIA_VIRTUAL (binfo))
2442 CLASSTYPE_VBASECLASSES (type)
2443 = tree_cons (BINFO_TYPE (binfo),
2445 CLASSTYPE_VBASECLASSES (type));
2446 SET_BINFO_MARKED (binfo);
2450 /* Called via dfs_walk from mark_primary_bases. Builds the
2451 inheritance graph order list of BINFOs. */
2454 dfs_build_inheritance_graph_order (binfo, data)
2458 tree *last_binfo = (tree *) data;
2461 TREE_CHAIN (*last_binfo) = binfo;
2462 *last_binfo = binfo;
2463 SET_BINFO_MARKED (binfo);
2467 /* Set CLASSTYPE_VBASECLASSES for TYPE. */
2470 get_vbase_types (type)
2475 CLASSTYPE_VBASECLASSES (type) = NULL_TREE;
2476 dfs_walk (TYPE_BINFO (type), dfs_get_vbase_types, unmarkedp, type);
2477 /* Rely upon the reverse dfs ordering from dfs_get_vbase_types, and now
2478 reverse it so that we get normal dfs ordering. */
2479 CLASSTYPE_VBASECLASSES (type) = nreverse (CLASSTYPE_VBASECLASSES (type));
2480 dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, 0);
2481 /* Thread the BINFOs in inheritance-graph order. */
2483 dfs_walk_real (TYPE_BINFO (type),
2484 dfs_build_inheritance_graph_order,
2488 dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, NULL);
2491 /* Called from find_vbase_instance via dfs_walk. */
2494 dfs_find_vbase_instance (binfo, data)
2498 tree base = TREE_VALUE ((tree) data);
2500 if (BINFO_PRIMARY_P (binfo)
2501 && same_type_p (BINFO_TYPE (binfo), base))
2507 /* Find the real occurrence of the virtual BASE (a class type) in the
2508 hierarchy dominated by TYPE. */
2511 find_vbase_instance (base, type)
2517 instance = binfo_for_vbase (base, type);
2518 if (!BINFO_PRIMARY_P (instance))
2521 return dfs_walk (TYPE_BINFO (type),
2522 dfs_find_vbase_instance,
2524 build_tree_list (type, base));
2528 /* Debug info for C++ classes can get very large; try to avoid
2529 emitting it everywhere.
2531 Note that this optimization wins even when the target supports
2532 BINCL (if only slightly), and reduces the amount of work for the
2536 maybe_suppress_debug_info (t)
2539 /* We can't do the usual TYPE_DECL_SUPPRESS_DEBUG thing with DWARF, which
2540 does not support name references between translation units. It supports
2541 symbolic references between translation units, but only within a single
2542 executable or shared library.
2544 For DWARF 2, we handle TYPE_DECL_SUPPRESS_DEBUG by pretending
2545 that the type was never defined, so we only get the members we
2547 if (write_symbols == DWARF_DEBUG || write_symbols == NO_DEBUG)
2550 /* We might have set this earlier in cp_finish_decl. */
2551 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 0;
2553 /* If we already know how we're handling this class, handle debug info
2555 if (CLASSTYPE_INTERFACE_KNOWN (t))
2557 if (CLASSTYPE_INTERFACE_ONLY (t))
2558 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
2559 /* else don't set it. */
2561 /* If the class has a vtable, write out the debug info along with
2563 else if (TYPE_CONTAINS_VPTR_P (t))
2564 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
2566 /* Otherwise, just emit the debug info normally. */
2569 /* Note that we want debugging information for a base class of a class
2570 whose vtable is being emitted. Normally, this would happen because
2571 calling the constructor for a derived class implies calling the
2572 constructors for all bases, which involve initializing the
2573 appropriate vptr with the vtable for the base class; but in the
2574 presence of optimization, this initialization may be optimized
2575 away, so we tell finish_vtable_vardecl that we want the debugging
2576 information anyway. */
2579 dfs_debug_mark (binfo, data)
2581 void *data ATTRIBUTE_UNUSED;
2583 tree t = BINFO_TYPE (binfo);
2585 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
2590 /* Returns BINFO if we haven't already noted that we want debugging
2591 info for this base class. */
2594 dfs_debug_unmarkedp (binfo, data)
2596 void *data ATTRIBUTE_UNUSED;
2598 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo))
2599 ? binfo : NULL_TREE);
2602 /* Write out the debugging information for TYPE, whose vtable is being
2603 emitted. Also walk through our bases and note that we want to
2604 write out information for them. This avoids the problem of not
2605 writing any debug info for intermediate basetypes whose
2606 constructors, and thus the references to their vtables, and thus
2607 the vtables themselves, were optimized away. */
2610 note_debug_info_needed (type)
2613 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)))
2615 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)) = 0;
2616 rest_of_type_compilation (type, toplevel_bindings_p ());
2619 dfs_walk (TYPE_BINFO (type), dfs_debug_mark, dfs_debug_unmarkedp, 0);
2622 /* Subroutines of push_class_decls (). */
2624 /* Returns 1 iff BINFO is a base we shouldn't really be able to see into,
2625 because it (or one of the intermediate bases) depends on template parms. */
2628 dependent_base_p (binfo)
2631 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
2633 if (currently_open_class (TREE_TYPE (binfo)))
2635 if (uses_template_parms (TREE_TYPE (binfo)))
2642 setup_class_bindings (name, type_binding_p)
2646 tree type_binding = NULL_TREE;
2649 /* If we've already done the lookup for this declaration, we're
2651 if (IDENTIFIER_CLASS_VALUE (name))
2654 /* First, deal with the type binding. */
2657 type_binding = lookup_member (current_class_type, name,
2660 if (TREE_CODE (type_binding) == TREE_LIST
2661 && TREE_TYPE (type_binding) == error_mark_node)
2662 /* NAME is ambiguous. */
2663 push_class_level_binding (name, type_binding);
2665 pushdecl_class_level (type_binding);
2668 /* Now, do the value binding. */
2669 value_binding = lookup_member (current_class_type, name,
2674 && (TREE_CODE (value_binding) == TYPE_DECL
2675 || (TREE_CODE (value_binding) == TREE_LIST
2676 && TREE_TYPE (value_binding) == error_mark_node
2677 && (TREE_CODE (TREE_VALUE (value_binding))
2679 /* We found a type-binding, even when looking for a non-type
2680 binding. This means that we already processed this binding
2682 my_friendly_assert (type_binding_p, 19990401);
2683 else if (value_binding)
2685 if (TREE_CODE (value_binding) == TREE_LIST
2686 && TREE_TYPE (value_binding) == error_mark_node)
2687 /* NAME is ambiguous. */
2688 push_class_level_binding (name, value_binding);
2691 if (BASELINK_P (value_binding))
2692 /* NAME is some overloaded functions. */
2693 value_binding = TREE_VALUE (value_binding);
2694 pushdecl_class_level (value_binding);
2699 /* Push class-level declarations for any names appearing in BINFO that
2703 dfs_push_type_decls (binfo, data)
2705 void *data ATTRIBUTE_UNUSED;
2710 type = BINFO_TYPE (binfo);
2711 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2712 if (DECL_NAME (fields) && TREE_CODE (fields) == TYPE_DECL
2713 && !(!same_type_p (type, current_class_type)
2714 && template_self_reference_p (type, fields)))
2715 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/1);
2717 /* We can't just use BINFO_MARKED because envelope_add_decl uses
2718 DERIVED_FROM_P, which calls get_base_distance. */
2719 SET_BINFO_PUSHDECLS_MARKED (binfo);
2724 /* Push class-level declarations for any names appearing in BINFO that
2725 are not TYPE_DECLS. */
2728 dfs_push_decls (binfo, data)
2736 type = BINFO_TYPE (binfo);
2737 dep_base_p = (processing_template_decl && type != current_class_type
2738 && dependent_base_p (binfo));
2742 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2743 if (DECL_NAME (fields)
2744 && TREE_CODE (fields) != TYPE_DECL
2745 && TREE_CODE (fields) != USING_DECL)
2746 setup_class_bindings (DECL_NAME (fields), /*type_binding_p=*/0);
2747 else if (TREE_CODE (fields) == FIELD_DECL
2748 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2749 dfs_push_decls (TYPE_BINFO (TREE_TYPE (fields)), data);
2751 method_vec = (CLASS_TYPE_P (type)
2752 ? CLASSTYPE_METHOD_VEC (type) : NULL_TREE);
2758 /* Farm out constructors and destructors. */
2759 end = TREE_VEC_END (method_vec);
2761 for (methods = &TREE_VEC_ELT (method_vec, 2);
2762 *methods && methods != end;
2764 setup_class_bindings (DECL_NAME (OVL_CURRENT (*methods)),
2765 /*type_binding_p=*/0);
2769 CLEAR_BINFO_PUSHDECLS_MARKED (binfo);
2774 /* When entering the scope of a class, we cache all of the
2775 fields that that class provides within its inheritance
2776 lattice. Where ambiguities result, we mark them
2777 with `error_mark_node' so that if they are encountered
2778 without explicit qualification, we can emit an error
2782 push_class_decls (type)
2785 search_stack = push_search_level (search_stack, &search_obstack);
2787 /* Enter type declarations and mark. */
2788 dfs_walk (TYPE_BINFO (type), dfs_push_type_decls, unmarked_pushdecls_p, 0);
2790 /* Enter non-type declarations and unmark. */
2791 dfs_walk (TYPE_BINFO (type), dfs_push_decls, marked_pushdecls_p, 0);
2794 /* Here's a subroutine we need because C lacks lambdas. */
2797 dfs_unuse_fields (binfo, data)
2799 void *data ATTRIBUTE_UNUSED;
2801 tree type = TREE_TYPE (binfo);
2804 for (fields = TYPE_FIELDS (type); fields; fields = TREE_CHAIN (fields))
2806 if (TREE_CODE (fields) != FIELD_DECL)
2809 TREE_USED (fields) = 0;
2810 if (DECL_NAME (fields) == NULL_TREE
2811 && ANON_AGGR_TYPE_P (TREE_TYPE (fields)))
2812 unuse_fields (TREE_TYPE (fields));
2822 dfs_walk (TYPE_BINFO (type), dfs_unuse_fields, unmarkedp, 0);
2828 /* We haven't pushed a search level when dealing with cached classes,
2829 so we'd better not try to pop it. */
2831 search_stack = pop_search_level (search_stack);
2835 print_search_statistics ()
2837 #ifdef GATHER_STATISTICS
2838 fprintf (stderr, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
2839 n_fields_searched, n_calls_lookup_field, n_calls_lookup_field_1);
2840 fprintf (stderr, "%d fnfields searched in %d calls to lookup_fnfields\n",
2841 n_outer_fields_searched, n_calls_lookup_fnfields);
2842 fprintf (stderr, "%d calls to get_base_type\n", n_calls_get_base_type);
2843 #else /* GATHER_STATISTICS */
2844 fprintf (stderr, "no search statistics\n");
2845 #endif /* GATHER_STATISTICS */
2849 init_search_processing ()
2851 gcc_obstack_init (&search_obstack);
2855 reinit_search_statistics ()
2857 #ifdef GATHER_STATISTICS
2858 n_fields_searched = 0;
2859 n_calls_lookup_field = 0, n_calls_lookup_field_1 = 0;
2860 n_calls_lookup_fnfields = 0, n_calls_lookup_fnfields_1 = 0;
2861 n_calls_get_base_type = 0;
2862 n_outer_fields_searched = 0;
2863 n_contexts_saved = 0;
2864 #endif /* GATHER_STATISTICS */
2868 add_conversions (binfo, data)
2873 tree method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
2874 tree *conversions = (tree *) data;
2876 /* Some builtin types have no method vector, not even an empty one. */
2880 for (i = 2; i < TREE_VEC_LENGTH (method_vec); ++i)
2882 tree tmp = TREE_VEC_ELT (method_vec, i);
2885 if (!tmp || ! DECL_CONV_FN_P (OVL_CURRENT (tmp)))
2888 name = DECL_NAME (OVL_CURRENT (tmp));
2890 /* Make sure we don't already have this conversion. */
2891 if (! IDENTIFIER_MARKED (name))
2893 *conversions = tree_cons (binfo, tmp, *conversions);
2894 IDENTIFIER_MARKED (name) = 1;
2900 /* Return a TREE_LIST containing all the non-hidden user-defined
2901 conversion functions for TYPE (and its base-classes). The
2902 TREE_VALUE of each node is a FUNCTION_DECL or an OVERLOAD
2903 containing the conversion functions. The TREE_PURPOSE is the BINFO
2904 from which the conversion functions in this node were selected. */
2907 lookup_conversions (type)
2911 tree conversions = NULL_TREE;
2913 if (COMPLETE_TYPE_P (type))
2914 bfs_walk (TYPE_BINFO (type), add_conversions, 0, &conversions);
2916 for (t = conversions; t; t = TREE_CHAIN (t))
2917 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (t)))) = 0;
2928 /* Check whether the empty class indicated by EMPTY_BINFO is also present
2929 at offset 0 in COMPARE_TYPE, and set found_overlap if so. */
2932 dfs_check_overlap (empty_binfo, data)
2936 struct overlap_info *oi = (struct overlap_info *) data;
2938 for (binfo = TYPE_BINFO (oi->compare_type);
2940 binfo = BINFO_BASETYPE (binfo, 0))
2942 if (BINFO_TYPE (binfo) == BINFO_TYPE (empty_binfo))
2944 oi->found_overlap = 1;
2947 else if (BINFO_BASETYPES (binfo) == NULL_TREE)
2954 /* Trivial function to stop base traversal when we find something. */
2957 dfs_no_overlap_yet (binfo, data)
2961 struct overlap_info *oi = (struct overlap_info *) data;
2962 return !oi->found_overlap ? binfo : NULL_TREE;
2965 /* Returns nonzero if EMPTY_TYPE or any of its bases can also be found at
2966 offset 0 in NEXT_TYPE. Used in laying out empty base class subobjects. */
2969 types_overlap_p (empty_type, next_type)
2970 tree empty_type, next_type;
2972 struct overlap_info oi;
2974 if (! IS_AGGR_TYPE (next_type))
2976 oi.compare_type = next_type;
2977 oi.found_overlap = 0;
2978 dfs_walk (TYPE_BINFO (empty_type), dfs_check_overlap,
2979 dfs_no_overlap_yet, &oi);
2980 return oi.found_overlap;
2983 /* Given a vtable VAR, determine which of the inherited classes the vtable
2984 inherits (in a loose sense) functions from.
2986 FIXME: This does not work with the new ABI. */
2989 binfo_for_vtable (var)
2992 tree main_binfo = TYPE_BINFO (DECL_CONTEXT (var));
2993 tree binfos = TYPE_BINFO_BASETYPES (BINFO_TYPE (main_binfo));
2994 int n_baseclasses = CLASSTYPE_N_BASECLASSES (BINFO_TYPE (main_binfo));
2997 for (i = 0; i < n_baseclasses; i++)
2999 tree base_binfo = TREE_VEC_ELT (binfos, i);
3000 if (base_binfo != NULL_TREE && BINFO_VTABLE (base_binfo) == var)
3004 /* If no secondary base classes matched, return the primary base, if
3006 if (CLASSTYPE_HAS_PRIMARY_BASE_P (BINFO_TYPE (main_binfo)))
3007 return get_primary_binfo (main_binfo);
3012 /* Returns the binfo of the first direct or indirect virtual base derived
3013 from BINFO, or NULL if binfo is not via virtual. */
3016 binfo_from_vbase (binfo)
3019 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
3021 if (TREE_VIA_VIRTUAL (binfo))
3027 /* Returns the binfo of the first direct or indirect virtual base derived
3028 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
3032 binfo_via_virtual (binfo, limit)
3036 for (; binfo && (!limit || !same_type_p (BINFO_TYPE (binfo), limit));
3037 binfo = BINFO_INHERITANCE_CHAIN (binfo))
3039 if (TREE_VIA_VIRTUAL (binfo))
3045 /* Returns the BINFO (if any) for the virtual baseclass T of the class
3046 C from the CLASSTYPE_VBASECLASSES list. */
3049 binfo_for_vbase (basetype, classtype)
3055 binfo = purpose_member (basetype, CLASSTYPE_VBASECLASSES (classtype));
3056 return binfo ? TREE_VALUE (binfo) : NULL_TREE;