1 /* Breadth-first and depth-first routines for
2 searching multiple-inheritance lattice for GNU C++.
3 Copyright (C) 1987, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
4 1999, 2000, 2002, 2003, 2004 Free Software Foundation, Inc.
5 Contributed by Michael Tiemann (tiemann@cygnus.com)
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING. If not, write to
21 the Free Software Foundation, 59 Temple Place - Suite 330,
22 Boston, MA 02111-1307, USA. */
24 /* High-level class interface. */
28 #include "coretypes.h"
39 static int is_subobject_of_p (tree, tree);
40 static base_kind lookup_base_r (tree, tree, base_access, bool, tree *);
41 static int dynamic_cast_base_recurse (tree, tree, bool, tree *);
42 static tree dfs_debug_mark (tree, void *);
43 static tree dfs_walk_once_r (tree, tree (*pre_fn) (tree, void *),
44 tree (*post_fn) (tree, void *), void *data);
45 static void dfs_unmark_r (tree);
46 static int check_hidden_convs (tree, int, int, tree, tree, tree);
47 static tree split_conversions (tree, tree, tree, tree);
48 static int lookup_conversions_r (tree, int, int,
49 tree, tree, tree, tree, tree *, tree *);
50 static int look_for_overrides_r (tree, tree);
51 static tree lookup_field_r (tree, void *);
52 static tree accessible_r (tree, bool);
53 static tree dfs_access_in_type (tree, void *);
54 static access_kind access_in_type (tree, tree);
55 static int protected_accessible_p (tree, tree, tree);
56 static int friend_accessible_p (tree, tree, tree);
57 static int template_self_reference_p (tree, tree);
58 static tree dfs_get_pure_virtuals (tree, void *);
61 /* Variables for gathering statistics. */
62 #ifdef GATHER_STATISTICS
63 static int n_fields_searched;
64 static int n_calls_lookup_field, n_calls_lookup_field_1;
65 static int n_calls_lookup_fnfields, n_calls_lookup_fnfields_1;
66 static int n_calls_get_base_type;
67 static int n_outer_fields_searched;
68 static int n_contexts_saved;
69 #endif /* GATHER_STATISTICS */
72 /* Worker for lookup_base. BINFO is the binfo we are searching at,
73 BASE is the RECORD_TYPE we are searching for. ACCESS is the
74 required access checks. IS_VIRTUAL indicates if BINFO is morally
77 If BINFO is of the required type, then *BINFO_PTR is examined to
78 compare with any other instance of BASE we might have already
79 discovered. *BINFO_PTR is initialized and a base_kind return value
80 indicates what kind of base was located.
82 Otherwise BINFO's bases are searched. */
85 lookup_base_r (tree binfo, tree base, base_access access,
86 bool is_virtual, /* inside a virtual part */
91 base_kind found = bk_not_base;
93 if (same_type_p (BINFO_TYPE (binfo), base))
95 /* We have found a base. Check against what we have found
99 found = bk_via_virtual;
103 else if (binfo != *binfo_ptr)
105 if (access != ba_any)
107 else if (!is_virtual)
108 /* Prefer a non-virtual base. */
116 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
120 bk = lookup_base_r (base_binfo, base,
122 is_virtual || BINFO_VIRTUAL_P (base_binfo),
128 if (access != ba_any)
137 gcc_assert (found == bk_not_base);
142 if (found != bk_ambig)
156 /* Returns true if type BASE is accessible in T. (BASE is known to be
157 a (possibly non-proper) base class of T.) */
160 accessible_base_p (tree t, tree base)
164 /* [class.access.base]
166 A base class is said to be accessible if an invented public
167 member of the base class is accessible.
169 If BASE is a non-proper base, this condition is trivially
171 if (same_type_p (t, base))
173 /* Rather than inventing a public member, we use the implicit
174 public typedef created in the scope of every class. */
175 decl = TYPE_FIELDS (base);
176 while (!DECL_SELF_REFERENCE_P (decl))
177 decl = TREE_CHAIN (decl);
178 while (ANON_AGGR_TYPE_P (t))
179 t = TYPE_CONTEXT (t);
180 return accessible_p (t, decl);
183 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
184 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
185 non-NULL, fill with information about what kind of base we
188 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
189 not set in ACCESS, then an error is issued and error_mark_node is
190 returned. If the ba_quiet bit is set, then no error is issued and
191 NULL_TREE is returned. */
194 lookup_base (tree t, tree base, base_access access, base_kind *kind_ptr)
196 tree binfo = NULL_TREE; /* The binfo we've found so far. */
197 tree t_binfo = NULL_TREE;
200 if (t == error_mark_node || base == error_mark_node)
203 *kind_ptr = bk_not_base;
204 return error_mark_node;
206 gcc_assert (TYPE_P (base));
215 t = complete_type (TYPE_MAIN_VARIANT (t));
216 t_binfo = TYPE_BINFO (t);
219 base = complete_type (TYPE_MAIN_VARIANT (base));
222 bk = lookup_base_r (t_binfo, base, access, 0, &binfo);
226 /* Check that the base is unambiguous and accessible. */
227 if (access != ba_any)
235 if (!(access & ba_quiet))
237 error ("`%T' is an ambiguous base of `%T'", base, t);
238 binfo = error_mark_node;
243 if ((access & ~ba_quiet) != ba_ignore
244 /* If BASE is incomplete, then BASE and TYPE are probably
245 the same, in which case BASE is accessible. If they
246 are not the same, then TYPE is invalid. In that case,
247 there's no need to issue another error here, and
248 there's no implicit typedef to use in the code that
249 follows, so we skip the check. */
250 && COMPLETE_TYPE_P (base)
251 && !accessible_base_p (t, base))
253 if (!(access & ba_quiet))
255 error ("`%T' is an inaccessible base of `%T'", base, t);
256 binfo = error_mark_node;
260 bk = bk_inaccessible;
271 /* Worker function for get_dynamic_cast_base_type. */
274 dynamic_cast_base_recurse (tree subtype, tree binfo, bool is_via_virtual,
277 VEC (tree) *accesses;
282 if (BINFO_TYPE (binfo) == subtype)
288 *offset_ptr = BINFO_OFFSET (binfo);
293 accesses = BINFO_BASE_ACCESSES (binfo);
294 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
296 tree base_access = VEC_index (tree, accesses, i);
299 if (base_access != access_public_node)
301 rval = dynamic_cast_base_recurse
302 (subtype, base_binfo,
303 is_via_virtual || BINFO_VIRTUAL_P (base_binfo), offset_ptr);
307 worst = worst >= 0 ? -3 : worst;
310 else if (rval == -3 && worst != -1)
316 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
317 started from is related to the required TARGET type, in order to optimize
318 the inheritance graph search. This information is independent of the
319 current context, and ignores private paths, hence get_base_distance is
320 inappropriate. Return a TREE specifying the base offset, BOFF.
321 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
322 and there are no public virtual SUBTYPE bases.
323 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
324 BOFF == -2, SUBTYPE is not a public base.
325 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
328 get_dynamic_cast_base_type (tree subtype, tree target)
330 tree offset = NULL_TREE;
331 int boff = dynamic_cast_base_recurse (subtype, TYPE_BINFO (target),
336 offset = ssize_int (boff);
340 /* Search for a member with name NAME in a multiple inheritance
341 lattice specified by TYPE. If it does not exist, return NULL_TREE.
342 If the member is ambiguously referenced, return `error_mark_node'.
343 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
344 true, type declarations are preferred. */
346 /* Do a 1-level search for NAME as a member of TYPE. The caller must
347 figure out whether it can access this field. (Since it is only one
348 level, this is reasonable.) */
351 lookup_field_1 (tree type, tree name, bool want_type)
355 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
356 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM
357 || TREE_CODE (type) == TYPENAME_TYPE)
358 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
359 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
360 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
361 the code often worked even when we treated the index as a list
363 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
367 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
368 && DECL_SORTED_FIELDS (TYPE_NAME (type)))
370 tree *fields = &DECL_SORTED_FIELDS (TYPE_NAME (type))->elts[0];
371 int lo = 0, hi = DECL_SORTED_FIELDS (TYPE_NAME (type))->len;
378 #ifdef GATHER_STATISTICS
380 #endif /* GATHER_STATISTICS */
382 if (DECL_NAME (fields[i]) > name)
384 else if (DECL_NAME (fields[i]) < name)
390 /* We might have a nested class and a field with the
391 same name; we sorted them appropriately via
392 field_decl_cmp, so just look for the first or last
393 field with this name. */
398 while (i >= lo && DECL_NAME (fields[i]) == name);
399 if (TREE_CODE (field) != TYPE_DECL
400 && !DECL_CLASS_TEMPLATE_P (field))
407 while (i < hi && DECL_NAME (fields[i]) == name);
415 field = TYPE_FIELDS (type);
417 #ifdef GATHER_STATISTICS
418 n_calls_lookup_field_1++;
419 #endif /* GATHER_STATISTICS */
420 for (field = TYPE_FIELDS (type); field; field = TREE_CHAIN (field))
422 #ifdef GATHER_STATISTICS
424 #endif /* GATHER_STATISTICS */
425 gcc_assert (DECL_P (field));
426 if (DECL_NAME (field) == NULL_TREE
427 && ANON_AGGR_TYPE_P (TREE_TYPE (field)))
429 tree temp = lookup_field_1 (TREE_TYPE (field), name, want_type);
433 if (TREE_CODE (field) == USING_DECL)
435 /* We generally treat class-scope using-declarations as
436 ARM-style access specifications, because support for the
437 ISO semantics has not been implemented. So, in general,
438 there's no reason to return a USING_DECL, and the rest of
439 the compiler cannot handle that. Once the class is
440 defined, USING_DECLs are purged from TYPE_FIELDS; see
441 handle_using_decl. However, we make special efforts to
442 make using-declarations in template classes work
444 if (CLASSTYPE_TEMPLATE_INFO (type)
445 && !CLASSTYPE_USE_TEMPLATE (type)
446 && !TREE_TYPE (field))
452 if (DECL_NAME (field) == name
454 || TREE_CODE (field) == TYPE_DECL
455 || DECL_CLASS_TEMPLATE_P (field)))
459 if (name == vptr_identifier)
461 /* Give the user what s/he thinks s/he wants. */
462 if (TYPE_POLYMORPHIC_P (type))
463 return TYPE_VFIELD (type);
468 /* There are a number of cases we need to be aware of here:
469 current_class_type current_function_decl
476 Those last two make life interesting. If we're in a function which is
477 itself inside a class, we need decls to go into the fn's decls (our
478 second case below). But if we're in a class and the class itself is
479 inside a function, we need decls to go into the decls for the class. To
480 achieve this last goal, we must see if, when both current_class_ptr and
481 current_function_decl are set, the class was declared inside that
482 function. If so, we know to put the decls into the class's scope. */
487 if (current_function_decl == NULL_TREE)
488 return current_class_type;
489 if (current_class_type == NULL_TREE)
490 return current_function_decl;
491 if ((DECL_FUNCTION_MEMBER_P (current_function_decl)
492 && same_type_p (DECL_CONTEXT (current_function_decl),
494 || (DECL_FRIEND_CONTEXT (current_function_decl)
495 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl),
496 current_class_type)))
497 return current_function_decl;
499 return current_class_type;
502 /* Returns nonzero if we are currently in a function scope. Note
503 that this function returns zero if we are within a local class, but
504 not within a member function body of the local class. */
507 at_function_scope_p (void)
509 tree cs = current_scope ();
510 return cs && TREE_CODE (cs) == FUNCTION_DECL;
513 /* Returns true if the innermost active scope is a class scope. */
516 at_class_scope_p (void)
518 tree cs = current_scope ();
519 return cs && TYPE_P (cs);
522 /* Returns true if the innermost active scope is a namespace scope. */
525 at_namespace_scope_p (void)
527 /* We are in a namespace scope if we are not it a class scope or a
529 return !current_scope();
532 /* Return the scope of DECL, as appropriate when doing name-lookup. */
535 context_for_name_lookup (tree decl)
539 For the purposes of name lookup, after the anonymous union
540 definition, the members of the anonymous union are considered to
541 have been defined in the scope in which the anonymous union is
543 tree context = DECL_CONTEXT (decl);
545 while (context && TYPE_P (context) && ANON_AGGR_TYPE_P (context))
546 context = TYPE_CONTEXT (context);
548 context = global_namespace;
553 /* The accessibility routines use BINFO_ACCESS for scratch space
554 during the computation of the accessibility of some declaration. */
556 #define BINFO_ACCESS(NODE) \
557 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
559 /* Set the access associated with NODE to ACCESS. */
561 #define SET_BINFO_ACCESS(NODE, ACCESS) \
562 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
563 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
565 /* Called from access_in_type via dfs_walk. Calculate the access to
566 DATA (which is really a DECL) in BINFO. */
569 dfs_access_in_type (tree binfo, void *data)
571 tree decl = (tree) data;
572 tree type = BINFO_TYPE (binfo);
573 access_kind access = ak_none;
575 if (context_for_name_lookup (decl) == type)
577 /* If we have descended to the scope of DECL, just note the
578 appropriate access. */
579 if (TREE_PRIVATE (decl))
581 else if (TREE_PROTECTED (decl))
582 access = ak_protected;
588 /* First, check for an access-declaration that gives us more
589 access to the DECL. The CONST_DECL for an enumeration
590 constant will not have DECL_LANG_SPECIFIC, and thus no
592 if (DECL_LANG_SPECIFIC (decl) && !DECL_DISCRIMINATOR_P (decl))
594 tree decl_access = purpose_member (type, DECL_ACCESS (decl));
598 decl_access = TREE_VALUE (decl_access);
600 if (decl_access == access_public_node)
602 else if (decl_access == access_protected_node)
603 access = ak_protected;
604 else if (decl_access == access_private_node)
615 VEC (tree) *accesses;
617 /* Otherwise, scan our baseclasses, and pick the most favorable
619 accesses = BINFO_BASE_ACCESSES (binfo);
620 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
622 tree base_access = VEC_index (tree, accesses, i);
623 access_kind base_access_now = BINFO_ACCESS (base_binfo);
625 if (base_access_now == ak_none || base_access_now == ak_private)
626 /* If it was not accessible in the base, or only
627 accessible as a private member, we can't access it
629 base_access_now = ak_none;
630 else if (base_access == access_protected_node)
631 /* Public and protected members in the base become
633 base_access_now = ak_protected;
634 else if (base_access == access_private_node)
635 /* Public and protected members in the base become
637 base_access_now = ak_private;
639 /* See if the new access, via this base, gives more
640 access than our previous best access. */
641 if (base_access_now != ak_none
642 && (access == ak_none || base_access_now < access))
644 access = base_access_now;
646 /* If the new access is public, we can't do better. */
647 if (access == ak_public)
654 /* Note the access to DECL in TYPE. */
655 SET_BINFO_ACCESS (binfo, access);
660 /* Return the access to DECL in TYPE. */
663 access_in_type (tree type, tree decl)
665 tree binfo = TYPE_BINFO (type);
667 /* We must take into account
671 If a name can be reached by several paths through a multiple
672 inheritance graph, the access is that of the path that gives
675 The algorithm we use is to make a post-order depth-first traversal
676 of the base-class hierarchy. As we come up the tree, we annotate
677 each node with the most lenient access. */
678 dfs_walk_once (binfo, NULL, dfs_access_in_type, decl);
680 return BINFO_ACCESS (binfo);
683 /* Returns nonzero if it is OK to access DECL through an object
684 indicated by BINFO in the context of DERIVED. */
687 protected_accessible_p (tree decl, tree derived, tree binfo)
691 /* We're checking this clause from [class.access.base]
693 m as a member of N is protected, and the reference occurs in a
694 member or friend of class N, or in a member or friend of a
695 class P derived from N, where m as a member of P is private or
698 Here DERIVED is a possible P and DECL is m. accessible_p will
699 iterate over various values of N, but the access to m in DERIVED
702 Note that I believe that the passage above is wrong, and should read
703 "...is private or protected or public"; otherwise you get bizarre results
704 whereby a public using-decl can prevent you from accessing a protected
705 member of a base. (jason 2000/02/28) */
707 /* If DERIVED isn't derived from m's class, then it can't be a P. */
708 if (!DERIVED_FROM_P (context_for_name_lookup (decl), derived))
711 access = access_in_type (derived, decl);
713 /* If m is inaccessible in DERIVED, then it's not a P. */
714 if (access == ak_none)
719 When a friend or a member function of a derived class references
720 a protected nonstatic member of a base class, an access check
721 applies in addition to those described earlier in clause
722 _class.access_) Except when forming a pointer to member
723 (_expr.unary.op_), the access must be through a pointer to,
724 reference to, or object of the derived class itself (or any class
725 derived from that class) (_expr.ref_). If the access is to form
726 a pointer to member, the nested-name-specifier shall name the
727 derived class (or any class derived from that class). */
728 if (DECL_NONSTATIC_MEMBER_P (decl))
730 /* We can tell through what the reference is occurring by
731 chasing BINFO up to the root. */
733 while (BINFO_INHERITANCE_CHAIN (t))
734 t = BINFO_INHERITANCE_CHAIN (t);
736 if (!DERIVED_FROM_P (derived, BINFO_TYPE (t)))
743 /* Returns nonzero if SCOPE is a friend of a type which would be able
744 to access DECL through the object indicated by BINFO. */
747 friend_accessible_p (tree scope, tree decl, tree binfo)
749 tree befriending_classes;
755 if (TREE_CODE (scope) == FUNCTION_DECL
756 || DECL_FUNCTION_TEMPLATE_P (scope))
757 befriending_classes = DECL_BEFRIENDING_CLASSES (scope);
758 else if (TYPE_P (scope))
759 befriending_classes = CLASSTYPE_BEFRIENDING_CLASSES (scope);
763 for (t = befriending_classes; t; t = TREE_CHAIN (t))
764 if (protected_accessible_p (decl, TREE_VALUE (t), binfo))
767 /* Nested classes are implicitly friends of their enclosing types, as
768 per core issue 45 (this is a change from the standard). */
770 for (t = TYPE_CONTEXT (scope); t && TYPE_P (t); t = TYPE_CONTEXT (t))
771 if (protected_accessible_p (decl, t, binfo))
774 if (TREE_CODE (scope) == FUNCTION_DECL
775 || DECL_FUNCTION_TEMPLATE_P (scope))
777 /* Perhaps this SCOPE is a member of a class which is a
779 if (DECL_CLASS_SCOPE_P (decl)
780 && friend_accessible_p (DECL_CONTEXT (scope), decl, binfo))
783 /* Or an instantiation of something which is a friend. */
784 if (DECL_TEMPLATE_INFO (scope))
787 /* Increment processing_template_decl to make sure that
788 dependent_type_p works correctly. */
789 ++processing_template_decl;
790 ret = friend_accessible_p (DECL_TI_TEMPLATE (scope), decl, binfo);
791 --processing_template_decl;
795 else if (CLASSTYPE_TEMPLATE_INFO (scope))
798 /* Increment processing_template_decl to make sure that
799 dependent_type_p works correctly. */
800 ++processing_template_decl;
801 ret = friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope), decl, binfo);
802 --processing_template_decl;
810 accessible_r (tree binfo, bool once)
812 tree rval = NULL_TREE;
816 /* Find the next child binfo to walk. */
817 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
819 bool mark = once && BINFO_VIRTUAL_P (base_binfo);
821 if (mark && BINFO_MARKED (base_binfo))
824 /* If the base is inherited via private or protected
825 inheritance, then we can't see it, unless we are a friend of
826 the current binfo. */
827 if (BINFO_BASE_ACCESS (binfo, ix) != access_public_node
828 && !is_friend (BINFO_TYPE (binfo), current_scope ()))
832 BINFO_MARKED (base_binfo) = 1;
834 rval = accessible_r (base_binfo, once);
839 if (BINFO_ACCESS (binfo) != ak_none
840 && is_friend (BINFO_TYPE (binfo), current_scope ()))
846 /* DECL is a declaration from a base class of TYPE, which was the
847 class used to name DECL. Return nonzero if, in the current
848 context, DECL is accessible. If TYPE is actually a BINFO node,
849 then we can tell in what context the access is occurring by looking
850 at the most derived class along the path indicated by BINFO. */
853 accessible_p (tree type, tree decl)
860 /* Nonzero if it's OK to access DECL if it has protected
861 accessibility in TYPE. */
862 int protected_ok = 0;
864 /* If this declaration is in a block or namespace scope, there's no
866 if (!TYPE_P (context_for_name_lookup (decl)))
869 /* There is no need to perform access checks inside a thunk. */
870 scope = current_scope ();
871 if (scope && DECL_THUNK_P (scope))
874 /* In a template declaration, we cannot be sure whether the
875 particular specialization that is instantiated will be a friend
876 or not. Therefore, all access checks are deferred until
878 if (processing_template_decl)
884 type = BINFO_TYPE (type);
887 binfo = TYPE_BINFO (type);
889 /* [class.access.base]
891 A member m is accessible when named in class N if
893 --m as a member of N is public, or
895 --m as a member of N is private, and the reference occurs in a
896 member or friend of class N, or
898 --m as a member of N is protected, and the reference occurs in a
899 member or friend of class N, or in a member or friend of a
900 class P derived from N, where m as a member of P is private or
903 --there exists a base class B of N that is accessible at the point
904 of reference, and m is accessible when named in class B.
906 We walk the base class hierarchy, checking these conditions. */
908 /* Figure out where the reference is occurring. Check to see if
909 DECL is private or protected in this scope, since that will
910 determine whether protected access is allowed. */
911 if (current_class_type)
912 protected_ok = protected_accessible_p (decl, current_class_type, binfo);
914 /* Now, loop through the classes of which we are a friend. */
916 protected_ok = friend_accessible_p (scope, decl, binfo);
918 /* Standardize the binfo that access_in_type will use. We don't
919 need to know what path was chosen from this point onwards. */
920 binfo = TYPE_BINFO (type);
922 /* Compute the accessibility of DECL in the class hierarchy
923 dominated by type. */
924 access = access_in_type (type, decl);
925 if (access == ak_public
926 || (access == ak_protected && protected_ok))
930 /* Walk the hierarchy again, looking for a base class that allows
933 (binfo, CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)));
935 if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)))
936 ;/* We are not diamond shaped, and therefore cannot
937 encounter the same binfo twice. */
938 else if (!BINFO_INHERITANCE_CHAIN (binfo))
940 /* We are at the top of the hierachy, and can use the
941 CLASSTYPE_VBASECLASSES list for unmarking the virtual
947 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0;
948 VEC_iterate (tree, vbases, ix, base_binfo); ix++)
949 BINFO_MARKED (base_binfo) = 0;
952 dfs_unmark_r (binfo);
954 return t != NULL_TREE;
958 struct lookup_field_info {
959 /* The type in which we're looking. */
961 /* The name of the field for which we're looking. */
963 /* If non-NULL, the current result of the lookup. */
965 /* The path to RVAL. */
967 /* If non-NULL, the lookup was ambiguous, and this is a list of the
970 /* If nonzero, we are looking for types, not data members. */
972 /* If something went wrong, a message indicating what. */
976 /* Within the scope of a template class, you can refer to the to the
977 current specialization with the name of the template itself. For
980 template <typename T> struct S { S* sp; }
982 Returns nonzero if DECL is such a declaration in a class TYPE. */
985 template_self_reference_p (tree type, tree decl)
987 return (CLASSTYPE_USE_TEMPLATE (type)
988 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type))
989 && TREE_CODE (decl) == TYPE_DECL
990 && DECL_ARTIFICIAL (decl)
991 && DECL_NAME (decl) == constructor_name (type));
994 /* Nonzero for a class member means that it is shared between all objects
997 [class.member.lookup]:If the resulting set of declarations are not all
998 from sub-objects of the same type, or the set has a nonstatic member
999 and includes members from distinct sub-objects, there is an ambiguity
1000 and the program is ill-formed.
1002 This function checks that T contains no nonstatic members. */
1005 shared_member_p (tree t)
1007 if (TREE_CODE (t) == VAR_DECL || TREE_CODE (t) == TYPE_DECL \
1008 || TREE_CODE (t) == CONST_DECL)
1010 if (is_overloaded_fn (t))
1012 for (; t; t = OVL_NEXT (t))
1014 tree fn = OVL_CURRENT (t);
1015 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn))
1023 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1024 found as a base class and sub-object of the object denoted by
1028 is_subobject_of_p (tree parent, tree binfo)
1032 for (probe = parent; probe; probe = BINFO_INHERITANCE_CHAIN (probe))
1036 if (BINFO_VIRTUAL_P (probe))
1037 return (binfo_for_vbase (BINFO_TYPE (probe), BINFO_TYPE (binfo))
1043 /* DATA is really a struct lookup_field_info. Look for a field with
1044 the name indicated there in BINFO. If this function returns a
1045 non-NULL value it is the result of the lookup. Called from
1046 lookup_field via breadth_first_search. */
1049 lookup_field_r (tree binfo, void *data)
1051 struct lookup_field_info *lfi = (struct lookup_field_info *) data;
1052 tree type = BINFO_TYPE (binfo);
1053 tree nval = NULL_TREE;
1055 /* If this is a dependent base, don't look in it. */
1056 if (BINFO_DEPENDENT_BASE_P (binfo))
1059 /* If this base class is hidden by the best-known value so far, we
1060 don't need to look. */
1061 if (lfi->rval_binfo && BINFO_INHERITANCE_CHAIN (binfo) == lfi->rval_binfo
1062 && !BINFO_VIRTUAL_P (binfo))
1063 return dfs_skip_bases;
1065 /* First, look for a function. There can't be a function and a data
1066 member with the same name, and if there's a function and a type
1067 with the same name, the type is hidden by the function. */
1068 if (!lfi->want_type)
1070 int idx = lookup_fnfields_1 (type, lfi->name);
1072 nval = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), idx);
1076 /* Look for a data member or type. */
1077 nval = lookup_field_1 (type, lfi->name, lfi->want_type);
1079 /* If there is no declaration with the indicated name in this type,
1080 then there's nothing to do. */
1084 /* If we're looking up a type (as with an elaborated type specifier)
1085 we ignore all non-types we find. */
1086 if (lfi->want_type && TREE_CODE (nval) != TYPE_DECL
1087 && !DECL_CLASS_TEMPLATE_P (nval))
1089 if (lfi->name == TYPE_IDENTIFIER (type))
1091 /* If the aggregate has no user defined constructors, we allow
1092 it to have fields with the same name as the enclosing type.
1093 If we are looking for that name, find the corresponding
1095 for (nval = TREE_CHAIN (nval); nval; nval = TREE_CHAIN (nval))
1096 if (DECL_NAME (nval) == lfi->name
1097 && TREE_CODE (nval) == TYPE_DECL)
1102 if (!nval && CLASSTYPE_NESTED_UTDS (type) != NULL)
1104 binding_entry e = binding_table_find (CLASSTYPE_NESTED_UTDS (type),
1107 nval = TYPE_MAIN_DECL (e->type);
1113 /* You must name a template base class with a template-id. */
1114 if (!same_type_p (type, lfi->type)
1115 && template_self_reference_p (type, nval))
1118 /* If the lookup already found a match, and the new value doesn't
1119 hide the old one, we might have an ambiguity. */
1121 && !is_subobject_of_p (lfi->rval_binfo, binfo))
1124 if (nval == lfi->rval && shared_member_p (nval))
1125 /* The two things are really the same. */
1127 else if (is_subobject_of_p (binfo, lfi->rval_binfo))
1128 /* The previous value hides the new one. */
1132 /* We have a real ambiguity. We keep a chain of all the
1134 if (!lfi->ambiguous && lfi->rval)
1136 /* This is the first time we noticed an ambiguity. Add
1137 what we previously thought was a reasonable candidate
1139 lfi->ambiguous = tree_cons (NULL_TREE, lfi->rval, NULL_TREE);
1140 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1143 /* Add the new value. */
1144 lfi->ambiguous = tree_cons (NULL_TREE, nval, lfi->ambiguous);
1145 TREE_TYPE (lfi->ambiguous) = error_mark_node;
1146 lfi->errstr = "request for member `%D' is ambiguous";
1152 lfi->rval_binfo = binfo;
1156 /* Don't look for constructors or destructors in base classes. */
1157 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
1158 return dfs_skip_bases;
1162 /* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1163 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1164 FUNCTIONS, and OPTYPE respectively. */
1167 build_baselink (tree binfo, tree access_binfo, tree functions, tree optype)
1171 gcc_assert (TREE_CODE (functions) == FUNCTION_DECL
1172 || TREE_CODE (functions) == TEMPLATE_DECL
1173 || TREE_CODE (functions) == TEMPLATE_ID_EXPR
1174 || TREE_CODE (functions) == OVERLOAD);
1175 gcc_assert (!optype || TYPE_P (optype));
1176 gcc_assert (TREE_TYPE (functions));
1178 baselink = make_node (BASELINK);
1179 TREE_TYPE (baselink) = TREE_TYPE (functions);
1180 BASELINK_BINFO (baselink) = binfo;
1181 BASELINK_ACCESS_BINFO (baselink) = access_binfo;
1182 BASELINK_FUNCTIONS (baselink) = functions;
1183 BASELINK_OPTYPE (baselink) = optype;
1188 /* Look for a member named NAME in an inheritance lattice dominated by
1189 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1190 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1191 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1192 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1193 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1194 TREE_VALUEs are the list of ambiguous candidates.
1196 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1198 If nothing can be found return NULL_TREE and do not issue an error. */
1201 lookup_member (tree xbasetype, tree name, int protect, bool want_type)
1203 tree rval, rval_binfo = NULL_TREE;
1204 tree type = NULL_TREE, basetype_path = NULL_TREE;
1205 struct lookup_field_info lfi;
1207 /* rval_binfo is the binfo associated with the found member, note,
1208 this can be set with useful information, even when rval is not
1209 set, because it must deal with ALL members, not just non-function
1210 members. It is used for ambiguity checking and the hidden
1211 checks. Whereas rval is only set if a proper (not hidden)
1212 non-function member is found. */
1214 const char *errstr = 0;
1216 gcc_assert (TREE_CODE (name) == IDENTIFIER_NODE);
1218 if (TREE_CODE (xbasetype) == TREE_BINFO)
1220 type = BINFO_TYPE (xbasetype);
1221 basetype_path = xbasetype;
1225 gcc_assert (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype)));
1227 xbasetype = NULL_TREE;
1230 type = complete_type (type);
1232 basetype_path = TYPE_BINFO (type);
1237 #ifdef GATHER_STATISTICS
1238 n_calls_lookup_field++;
1239 #endif /* GATHER_STATISTICS */
1241 memset (&lfi, 0, sizeof (lfi));
1244 lfi.want_type = want_type;
1245 dfs_walk_all (basetype_path, &lookup_field_r, NULL, &lfi);
1247 rval_binfo = lfi.rval_binfo;
1249 type = BINFO_TYPE (rval_binfo);
1250 errstr = lfi.errstr;
1252 /* If we are not interested in ambiguities, don't report them;
1253 just return NULL_TREE. */
1254 if (!protect && lfi.ambiguous)
1260 return lfi.ambiguous;
1267 In the case of overloaded function names, access control is
1268 applied to the function selected by overloaded resolution. */
1269 if (rval && protect && !is_overloaded_fn (rval))
1270 perform_or_defer_access_check (basetype_path, rval);
1272 if (errstr && protect)
1274 error (errstr, name, type);
1276 print_candidates (lfi.ambiguous);
1277 rval = error_mark_node;
1280 if (rval && is_overloaded_fn (rval))
1281 rval = build_baselink (rval_binfo, basetype_path, rval,
1282 (IDENTIFIER_TYPENAME_P (name)
1283 ? TREE_TYPE (name): NULL_TREE));
1287 /* Like lookup_member, except that if we find a function member we
1288 return NULL_TREE. */
1291 lookup_field (tree xbasetype, tree name, int protect, bool want_type)
1293 tree rval = lookup_member (xbasetype, name, protect, want_type);
1295 /* Ignore functions, but propagate the ambiguity list. */
1296 if (!error_operand_p (rval)
1297 && (rval && BASELINK_P (rval)))
1303 /* Like lookup_member, except that if we find a non-function member we
1304 return NULL_TREE. */
1307 lookup_fnfields (tree xbasetype, tree name, int protect)
1309 tree rval = lookup_member (xbasetype, name, protect, /*want_type=*/false);
1311 /* Ignore non-functions, but propagate the ambiguity list. */
1312 if (!error_operand_p (rval)
1313 && (rval && !BASELINK_P (rval)))
1319 /* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE
1320 corresponding to "operator TYPE ()", or -1 if there is no such
1321 operator. Only CLASS_TYPE itself is searched; this routine does
1322 not scan the base classes of CLASS_TYPE. */
1325 lookup_conversion_operator (tree class_type, tree type)
1329 if (TYPE_HAS_CONVERSION (class_type))
1333 VEC(tree) *methods = CLASSTYPE_METHOD_VEC (class_type);
1335 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1336 VEC_iterate (tree, methods, i, fn); ++i)
1338 /* All the conversion operators come near the beginning of
1339 the class. Therefore, if FN is not a conversion
1340 operator, there is no matching conversion operator in
1342 fn = OVL_CURRENT (fn);
1343 if (!DECL_CONV_FN_P (fn))
1346 if (TREE_CODE (fn) == TEMPLATE_DECL)
1347 /* All the templated conversion functions are on the same
1348 slot, so remember it. */
1350 else if (same_type_p (DECL_CONV_FN_TYPE (fn), type))
1358 /* TYPE is a class type. Return the index of the fields within
1359 the method vector with name NAME, or -1 is no such field exists. */
1362 lookup_fnfields_1 (tree type, tree name)
1364 VEC(tree) *method_vec;
1369 if (!CLASS_TYPE_P (type))
1372 if (COMPLETE_TYPE_P (type))
1374 if ((name == ctor_identifier
1375 || name == base_ctor_identifier
1376 || name == complete_ctor_identifier))
1378 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type))
1379 lazily_declare_fn (sfk_constructor, type);
1380 if (CLASSTYPE_LAZY_COPY_CTOR (type))
1381 lazily_declare_fn (sfk_copy_constructor, type);
1383 else if (name == ansi_assopname(NOP_EXPR)
1384 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type))
1385 lazily_declare_fn (sfk_assignment_operator, type);
1388 method_vec = CLASSTYPE_METHOD_VEC (type);
1392 #ifdef GATHER_STATISTICS
1393 n_calls_lookup_fnfields_1++;
1394 #endif /* GATHER_STATISTICS */
1396 /* Constructors are first... */
1397 if (name == ctor_identifier)
1399 fn = CLASSTYPE_CONSTRUCTORS (type);
1400 return fn ? CLASSTYPE_CONSTRUCTOR_SLOT : -1;
1402 /* and destructors are second. */
1403 if (name == dtor_identifier)
1405 fn = CLASSTYPE_DESTRUCTORS (type);
1406 return fn ? CLASSTYPE_DESTRUCTOR_SLOT : -1;
1408 if (IDENTIFIER_TYPENAME_P (name))
1409 return lookup_conversion_operator (type, TREE_TYPE (name));
1411 /* Skip the conversion operators. */
1412 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
1413 VEC_iterate (tree, method_vec, i, fn);
1415 if (!DECL_CONV_FN_P (OVL_CURRENT (fn)))
1418 /* If the type is complete, use binary search. */
1419 if (COMPLETE_TYPE_P (type))
1425 hi = VEC_length (tree, method_vec);
1430 #ifdef GATHER_STATISTICS
1431 n_outer_fields_searched++;
1432 #endif /* GATHER_STATISTICS */
1434 tmp = VEC_index (tree, method_vec, i);
1435 tmp = DECL_NAME (OVL_CURRENT (tmp));
1438 else if (tmp < name)
1445 for (; VEC_iterate (tree, method_vec, i, fn); ++i)
1447 #ifdef GATHER_STATISTICS
1448 n_outer_fields_searched++;
1449 #endif /* GATHER_STATISTICS */
1450 if (DECL_NAME (OVL_CURRENT (fn)) == name)
1457 /* Like lookup_fnfields_1, except that the name is extracted from
1458 FUNCTION, which is a FUNCTION_DECL or a TEMPLATE_DECL. */
1461 class_method_index_for_fn (tree class_type, tree function)
1463 gcc_assert (TREE_CODE (function) == FUNCTION_DECL
1464 || DECL_FUNCTION_TEMPLATE_P (function));
1466 return lookup_fnfields_1 (class_type,
1467 DECL_CONSTRUCTOR_P (function) ? ctor_identifier :
1468 DECL_DESTRUCTOR_P (function) ? dtor_identifier :
1469 DECL_NAME (function));
1473 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1474 the class or namespace used to qualify the name. CONTEXT_CLASS is
1475 the class corresponding to the object in which DECL will be used.
1476 Return a possibly modified version of DECL that takes into account
1479 In particular, consider an expression like `B::m' in the context of
1480 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1481 then the most derived class indicated by the BASELINK_BINFO will be
1482 `B', not `D'. This function makes that adjustment. */
1485 adjust_result_of_qualified_name_lookup (tree decl,
1486 tree qualifying_scope,
1489 if (context_class && CLASS_TYPE_P (qualifying_scope)
1490 && DERIVED_FROM_P (qualifying_scope, context_class)
1491 && BASELINK_P (decl))
1495 gcc_assert (CLASS_TYPE_P (context_class));
1497 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1498 Because we do not yet know which function will be chosen by
1499 overload resolution, we cannot yet check either accessibility
1500 or ambiguity -- in either case, the choice of a static member
1501 function might make the usage valid. */
1502 base = lookup_base (context_class, qualifying_scope,
1503 ba_ignore | ba_quiet, NULL);
1506 BASELINK_ACCESS_BINFO (decl) = base;
1507 BASELINK_BINFO (decl)
1508 = lookup_base (base, BINFO_TYPE (BASELINK_BINFO (decl)),
1509 ba_ignore | ba_quiet,
1518 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
1519 PRE_FN is called in preorder, while POST_FN is called in postorder.
1520 If PRE_FN returns DFS_SKIP_BASES, child binfos will not be
1521 walked. If PRE_FN or POST_FN returns a different non-NULL value,
1522 that value is immediately returned and the walk is terminated. One
1523 of PRE_FN and POST_FN can be NULL. At each node, PRE_FN and
1524 POST_FN are passed the binfo to examine and the caller's DATA
1525 value. All paths are walked, thus virtual and morally virtual
1526 binfos can be multiply walked. */
1529 dfs_walk_all (tree binfo, tree (*pre_fn) (tree, void *),
1530 tree (*post_fn) (tree, void *), void *data)
1536 /* Call the pre-order walking function. */
1539 rval = pre_fn (binfo, data);
1542 if (rval == dfs_skip_bases)
1548 /* Find the next child binfo to walk. */
1549 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1551 rval = dfs_walk_all (base_binfo, pre_fn, post_fn, data);
1557 /* Call the post-order walking function. */
1559 return post_fn (binfo, data);
1563 /* Worker for dfs_walk_once. This behaves as dfs_walk_all, except
1564 that binfos are walked at most once. */
1567 dfs_walk_once_r (tree binfo, tree (*pre_fn) (tree, void *),
1568 tree (*post_fn) (tree, void *), void *data)
1574 /* Call the pre-order walking function. */
1577 rval = pre_fn (binfo, data);
1580 if (rval == dfs_skip_bases)
1587 /* Find the next child binfo to walk. */
1588 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1590 if (BINFO_VIRTUAL_P (base_binfo))
1592 if (BINFO_MARKED (base_binfo))
1594 BINFO_MARKED (base_binfo) = 1;
1597 rval = dfs_walk_once_r (base_binfo, pre_fn, post_fn, data);
1603 /* Call the post-order walking function. */
1605 return post_fn (binfo, data);
1610 /* Worker for dfs_walk_once. Recursively unmark the virtual base binfos of
1614 dfs_unmark_r (tree binfo)
1619 /* Process the basetypes. */
1620 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1622 if (BINFO_VIRTUAL_P (base_binfo))
1624 if (!BINFO_MARKED (base_binfo))
1626 BINFO_MARKED (base_binfo) = 0;
1628 /* Only walk, if it can contain more virtual bases. */
1629 if (CLASSTYPE_VBASECLASSES (BINFO_TYPE (base_binfo)))
1630 dfs_unmark_r (base_binfo);
1634 /* Like dfs_walk_all, except that binfos are not multiply walked. For
1635 non-diamond shaped hierarchies this is the same as dfs_walk_all.
1636 For diamond shaped hierarchies we must mark the virtual bases, to
1637 avoid multiple walks. */
1640 dfs_walk_once (tree binfo, tree (*pre_fn) (tree, void *),
1641 tree (*post_fn) (tree, void *), void *data)
1645 gcc_assert (pre_fn || post_fn);
1647 if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)))
1648 /* We are not diamond shaped, and therefore cannot encounter the
1649 same binfo twice. */
1650 rval = dfs_walk_all (binfo, pre_fn, post_fn, data);
1653 rval = dfs_walk_once_r (binfo, pre_fn, post_fn, data);
1654 if (!BINFO_INHERITANCE_CHAIN (binfo))
1656 /* We are at the top of the hierachy, and can use the
1657 CLASSTYPE_VBASECLASSES list for unmarking the virtual
1663 for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0;
1664 VEC_iterate (tree, vbases, ix, base_binfo); ix++)
1665 BINFO_MARKED (base_binfo) = 0;
1668 dfs_unmark_r (binfo);
1673 /* Check that virtual overrider OVERRIDER is acceptable for base function
1674 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1677 check_final_overrider (tree overrider, tree basefn)
1679 tree over_type = TREE_TYPE (overrider);
1680 tree base_type = TREE_TYPE (basefn);
1681 tree over_return = TREE_TYPE (over_type);
1682 tree base_return = TREE_TYPE (base_type);
1683 tree over_throw = TYPE_RAISES_EXCEPTIONS (over_type);
1684 tree base_throw = TYPE_RAISES_EXCEPTIONS (base_type);
1687 if (DECL_INVALID_OVERRIDER_P (overrider))
1690 if (same_type_p (base_return, over_return))
1692 else if ((CLASS_TYPE_P (over_return) && CLASS_TYPE_P (base_return))
1693 || (TREE_CODE (base_return) == TREE_CODE (over_return)
1694 && POINTER_TYPE_P (base_return)))
1696 /* Potentially covariant. */
1697 unsigned base_quals, over_quals;
1699 fail = !POINTER_TYPE_P (base_return);
1702 fail = cp_type_quals (base_return) != cp_type_quals (over_return);
1704 base_return = TREE_TYPE (base_return);
1705 over_return = TREE_TYPE (over_return);
1707 base_quals = cp_type_quals (base_return);
1708 over_quals = cp_type_quals (over_return);
1710 if ((base_quals & over_quals) != over_quals)
1713 if (CLASS_TYPE_P (base_return) && CLASS_TYPE_P (over_return))
1715 tree binfo = lookup_base (over_return, base_return,
1716 ba_check | ba_quiet, NULL);
1722 && can_convert (TREE_TYPE (base_type), TREE_TYPE (over_type)))
1723 /* GNU extension, allow trivial pointer conversions such as
1724 converting to void *, or qualification conversion. */
1726 /* can_convert will permit user defined conversion from a
1727 (reference to) class type. We must reject them. */
1728 over_return = non_reference (TREE_TYPE (over_type));
1729 if (CLASS_TYPE_P (over_return))
1743 cp_error_at ("invalid covariant return type for `%#D'", overrider);
1744 cp_error_at (" overriding `%#D'", basefn);
1748 cp_error_at ("conflicting return type specified for `%#D'",
1750 cp_error_at (" overriding `%#D'", basefn);
1752 DECL_INVALID_OVERRIDER_P (overrider) = 1;
1756 /* Check throw specifier is at least as strict. */
1757 if (!comp_except_specs (base_throw, over_throw, 0))
1759 cp_error_at ("looser throw specifier for `%#F'", overrider);
1760 cp_error_at (" overriding `%#F'", basefn);
1761 DECL_INVALID_OVERRIDER_P (overrider) = 1;
1768 /* Given a class TYPE, and a function decl FNDECL, look for
1769 virtual functions in TYPE's hierarchy which FNDECL overrides.
1770 We do not look in TYPE itself, only its bases.
1772 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1773 find that it overrides anything.
1775 We check that every function which is overridden, is correctly
1779 look_for_overrides (tree type, tree fndecl)
1781 tree binfo = TYPE_BINFO (type);
1786 for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
1788 tree basetype = BINFO_TYPE (base_binfo);
1790 if (TYPE_POLYMORPHIC_P (basetype))
1791 found += look_for_overrides_r (basetype, fndecl);
1796 /* Look in TYPE for virtual functions with the same signature as
1800 look_for_overrides_here (tree type, tree fndecl)
1804 /* If there are no methods in TYPE (meaning that only implicitly
1805 declared methods will ever be provided for TYPE), then there are
1806 no virtual functions. */
1807 if (!CLASSTYPE_METHOD_VEC (type))
1810 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl))
1811 ix = CLASSTYPE_DESTRUCTOR_SLOT;
1813 ix = lookup_fnfields_1 (type, DECL_NAME (fndecl));
1816 tree fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (type), ix);
1818 for (; fns; fns = OVL_NEXT (fns))
1820 tree fn = OVL_CURRENT (fns);
1822 if (!DECL_VIRTUAL_P (fn))
1823 /* Not a virtual. */;
1824 else if (DECL_CONTEXT (fn) != type)
1825 /* Introduced with a using declaration. */;
1826 else if (DECL_STATIC_FUNCTION_P (fndecl))
1828 tree btypes = TYPE_ARG_TYPES (TREE_TYPE (fn));
1829 tree dtypes = TYPE_ARG_TYPES (TREE_TYPE (fndecl));
1830 if (compparms (TREE_CHAIN (btypes), dtypes))
1833 else if (same_signature_p (fndecl, fn))
1840 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1841 TYPE itself and its bases. */
1844 look_for_overrides_r (tree type, tree fndecl)
1846 tree fn = look_for_overrides_here (type, fndecl);
1849 if (DECL_STATIC_FUNCTION_P (fndecl))
1851 /* A static member function cannot match an inherited
1852 virtual member function. */
1853 cp_error_at ("`%#D' cannot be declared", fndecl);
1854 cp_error_at (" since `%#D' declared in base class", fn);
1858 /* It's definitely virtual, even if not explicitly set. */
1859 DECL_VIRTUAL_P (fndecl) = 1;
1860 check_final_overrider (fndecl, fn);
1865 /* We failed to find one declared in this class. Look in its bases. */
1866 return look_for_overrides (type, fndecl);
1869 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1872 dfs_get_pure_virtuals (tree binfo, void *data)
1874 tree type = (tree) data;
1876 /* We're not interested in primary base classes; the derived class
1877 of which they are a primary base will contain the information we
1879 if (!BINFO_PRIMARY_P (binfo))
1883 for (virtuals = BINFO_VIRTUALS (binfo);
1885 virtuals = TREE_CHAIN (virtuals))
1886 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals)))
1887 VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (type),
1894 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1897 get_pure_virtuals (tree type)
1899 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1900 is going to be overridden. */
1901 CLASSTYPE_PURE_VIRTUALS (type) = NULL;
1902 /* Now, run through all the bases which are not primary bases, and
1903 collect the pure virtual functions. We look at the vtable in
1904 each class to determine what pure virtual functions are present.
1905 (A primary base is not interesting because the derived class of
1906 which it is a primary base will contain vtable entries for the
1907 pure virtuals in the base class. */
1908 dfs_walk_once (TYPE_BINFO (type), NULL, dfs_get_pure_virtuals, type);
1911 /* Debug info for C++ classes can get very large; try to avoid
1912 emitting it everywhere.
1914 Note that this optimization wins even when the target supports
1915 BINCL (if only slightly), and reduces the amount of work for the
1919 maybe_suppress_debug_info (tree t)
1921 if (write_symbols == NO_DEBUG)
1924 /* We might have set this earlier in cp_finish_decl. */
1925 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 0;
1927 /* If we already know how we're handling this class, handle debug info
1929 if (CLASSTYPE_INTERFACE_KNOWN (t))
1931 if (CLASSTYPE_INTERFACE_ONLY (t))
1932 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
1933 /* else don't set it. */
1935 /* If the class has a vtable, write out the debug info along with
1937 else if (TYPE_CONTAINS_VPTR_P (t))
1938 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t)) = 1;
1940 /* Otherwise, just emit the debug info normally. */
1943 /* Note that we want debugging information for a base class of a class
1944 whose vtable is being emitted. Normally, this would happen because
1945 calling the constructor for a derived class implies calling the
1946 constructors for all bases, which involve initializing the
1947 appropriate vptr with the vtable for the base class; but in the
1948 presence of optimization, this initialization may be optimized
1949 away, so we tell finish_vtable_vardecl that we want the debugging
1950 information anyway. */
1953 dfs_debug_mark (tree binfo, void *data ATTRIBUTE_UNUSED)
1955 tree t = BINFO_TYPE (binfo);
1957 if (CLASSTYPE_DEBUG_REQUESTED (t))
1958 return dfs_skip_bases;
1960 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
1965 /* Write out the debugging information for TYPE, whose vtable is being
1966 emitted. Also walk through our bases and note that we want to
1967 write out information for them. This avoids the problem of not
1968 writing any debug info for intermediate basetypes whose
1969 constructors, and thus the references to their vtables, and thus
1970 the vtables themselves, were optimized away. */
1973 note_debug_info_needed (tree type)
1975 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)))
1977 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type)) = 0;
1978 rest_of_type_compilation (type, toplevel_bindings_p ());
1981 dfs_walk_all (TYPE_BINFO (type), dfs_debug_mark, NULL, 0);
1985 print_search_statistics (void)
1987 #ifdef GATHER_STATISTICS
1988 fprintf (stderr, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
1989 n_fields_searched, n_calls_lookup_field, n_calls_lookup_field_1);
1990 fprintf (stderr, "%d fnfields searched in %d calls to lookup_fnfields\n",
1991 n_outer_fields_searched, n_calls_lookup_fnfields);
1992 fprintf (stderr, "%d calls to get_base_type\n", n_calls_get_base_type);
1993 #else /* GATHER_STATISTICS */
1994 fprintf (stderr, "no search statistics\n");
1995 #endif /* GATHER_STATISTICS */
1999 reinit_search_statistics (void)
2001 #ifdef GATHER_STATISTICS
2002 n_fields_searched = 0;
2003 n_calls_lookup_field = 0, n_calls_lookup_field_1 = 0;
2004 n_calls_lookup_fnfields = 0, n_calls_lookup_fnfields_1 = 0;
2005 n_calls_get_base_type = 0;
2006 n_outer_fields_searched = 0;
2007 n_contexts_saved = 0;
2008 #endif /* GATHER_STATISTICS */
2011 /* Helper for lookup_conversions_r. TO_TYPE is the type converted to
2012 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if
2013 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual
2014 bases have been encountered already in the tree walk. PARENT_CONVS
2015 is the list of lists of conversion functions that could hide CONV
2016 and OTHER_CONVS is the list of lists of conversion functions that
2017 could hide or be hidden by CONV, should virtualness be involved in
2018 the hierarchy. Merely checking the conversion op's name is not
2019 enough because two conversion operators to the same type can have
2020 different names. Return nonzero if we are visible. */
2023 check_hidden_convs (tree binfo, int virtual_depth, int virtualness,
2024 tree to_type, tree parent_convs, tree other_convs)
2028 /* See if we are hidden by a parent conversion. */
2029 for (level = parent_convs; level; level = TREE_CHAIN (level))
2030 for (probe = TREE_VALUE (level); probe; probe = TREE_CHAIN (probe))
2031 if (same_type_p (to_type, TREE_TYPE (probe)))
2034 if (virtual_depth || virtualness)
2036 /* In a virtual hierarchy, we could be hidden, or could hide a
2037 conversion function on the other_convs list. */
2038 for (level = other_convs; level; level = TREE_CHAIN (level))
2044 if (!(virtual_depth || TREE_STATIC (level)))
2045 /* Neither is morally virtual, so cannot hide each other. */
2048 if (!TREE_VALUE (level))
2049 /* They evaporated away already. */
2052 they_hide_us = (virtual_depth
2053 && original_binfo (binfo, TREE_PURPOSE (level)));
2054 we_hide_them = (!they_hide_us && TREE_STATIC (level)
2055 && original_binfo (TREE_PURPOSE (level), binfo));
2057 if (!(we_hide_them || they_hide_us))
2058 /* Neither is within the other, so no hiding can occur. */
2061 for (prev = &TREE_VALUE (level), other = *prev; other;)
2063 if (same_type_p (to_type, TREE_TYPE (other)))
2066 /* We are hidden. */
2071 /* We hide the other one. */
2072 other = TREE_CHAIN (other);
2077 prev = &TREE_CHAIN (other);
2085 /* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists
2086 of conversion functions, the first slot will be for the current
2087 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists
2088 of conversion functions from children of the current binfo,
2089 concatenated with conversions from elsewhere in the hierarchy --
2090 that list begins with OTHER_CONVS. Return a single list of lists
2091 containing only conversions from the current binfo and its
2095 split_conversions (tree my_convs, tree parent_convs,
2096 tree child_convs, tree other_convs)
2101 /* Remove the original other_convs portion from child_convs. */
2102 for (prev = NULL, t = child_convs;
2103 t != other_convs; prev = t, t = TREE_CHAIN (t))
2107 TREE_CHAIN (prev) = NULL_TREE;
2109 child_convs = NULL_TREE;
2111 /* Attach the child convs to any we had at this level. */
2114 my_convs = parent_convs;
2115 TREE_CHAIN (my_convs) = child_convs;
2118 my_convs = child_convs;
2123 /* Worker for lookup_conversions. Lookup conversion functions in
2124 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in
2125 a morally virtual base, and VIRTUALNESS is nonzero, if we've
2126 encountered virtual bases already in the tree walk. PARENT_CONVS &
2127 PARENT_TPL_CONVS are lists of list of conversions within parent
2128 binfos. OTHER_CONVS and OTHER_TPL_CONVS are conversions found
2129 elsewhere in the tree. Return the conversions found within this
2130 portion of the graph in CONVS and TPL_CONVS. Return nonzero is we
2131 encountered virtualness. We keep template and non-template
2132 conversions separate, to avoid unnecessary type comparisons.
2134 The located conversion functions are held in lists of lists. The
2135 TREE_VALUE of the outer list is the list of conversion functions
2136 found in a particular binfo. The TREE_PURPOSE of both the outer
2137 and inner lists is the binfo at which those conversions were
2138 found. TREE_STATIC is set for those lists within of morally
2139 virtual binfos. The TREE_VALUE of the inner list is the conversion
2140 function or overload itself. The TREE_TYPE of each inner list node
2141 is the converted-to type. */
2144 lookup_conversions_r (tree binfo,
2145 int virtual_depth, int virtualness,
2146 tree parent_convs, tree parent_tpl_convs,
2147 tree other_convs, tree other_tpl_convs,
2148 tree *convs, tree *tpl_convs)
2150 int my_virtualness = 0;
2151 tree my_convs = NULL_TREE;
2152 tree my_tpl_convs = NULL_TREE;
2153 tree child_convs = NULL_TREE;
2154 tree child_tpl_convs = NULL_TREE;
2157 VEC(tree) *method_vec = CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo));
2160 /* If we have no conversion operators, then don't look. */
2161 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo)))
2163 *convs = *tpl_convs = NULL_TREE;
2168 if (BINFO_VIRTUAL_P (binfo))
2171 /* First, locate the unhidden ones at this level. */
2172 for (i = CLASSTYPE_FIRST_CONVERSION_SLOT;
2173 VEC_iterate (tree, method_vec, i, conv);
2176 tree cur = OVL_CURRENT (conv);
2178 if (!DECL_CONV_FN_P (cur))
2181 if (TREE_CODE (cur) == TEMPLATE_DECL)
2183 /* Only template conversions can be overloaded, and we must
2184 flatten them out and check each one individually. */
2187 for (tpls = conv; tpls; tpls = OVL_NEXT (tpls))
2189 tree tpl = OVL_CURRENT (tpls);
2190 tree type = DECL_CONV_FN_TYPE (tpl);
2192 if (check_hidden_convs (binfo, virtual_depth, virtualness,
2193 type, parent_tpl_convs, other_tpl_convs))
2195 my_tpl_convs = tree_cons (binfo, tpl, my_tpl_convs);
2196 TREE_TYPE (my_tpl_convs) = type;
2199 TREE_STATIC (my_tpl_convs) = 1;
2207 tree name = DECL_NAME (cur);
2209 if (!IDENTIFIER_MARKED (name))
2211 tree type = DECL_CONV_FN_TYPE (cur);
2213 if (check_hidden_convs (binfo, virtual_depth, virtualness,
2214 type, parent_convs, other_convs))
2216 my_convs = tree_cons (binfo, conv, my_convs);
2217 TREE_TYPE (my_convs) = type;
2220 TREE_STATIC (my_convs) = 1;
2223 IDENTIFIER_MARKED (name) = 1;
2231 parent_convs = tree_cons (binfo, my_convs, parent_convs);
2233 TREE_STATIC (parent_convs) = 1;
2238 parent_tpl_convs = tree_cons (binfo, my_tpl_convs, parent_tpl_convs);
2240 TREE_STATIC (parent_convs) = 1;
2243 child_convs = other_convs;
2244 child_tpl_convs = other_tpl_convs;
2246 /* Now iterate over each base, looking for more conversions. */
2247 for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
2249 tree base_convs, base_tpl_convs;
2250 unsigned base_virtualness;
2252 base_virtualness = lookup_conversions_r (base_binfo,
2253 virtual_depth, virtualness,
2254 parent_convs, parent_tpl_convs,
2255 child_convs, child_tpl_convs,
2256 &base_convs, &base_tpl_convs);
2257 if (base_virtualness)
2258 my_virtualness = virtualness = 1;
2259 child_convs = chainon (base_convs, child_convs);
2260 child_tpl_convs = chainon (base_tpl_convs, child_tpl_convs);
2263 /* Unmark the conversions found at this level */
2264 for (conv = my_convs; conv; conv = TREE_CHAIN (conv))
2265 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (conv)))) = 0;
2267 *convs = split_conversions (my_convs, parent_convs,
2268 child_convs, other_convs);
2269 *tpl_convs = split_conversions (my_tpl_convs, parent_tpl_convs,
2270 child_tpl_convs, other_tpl_convs);
2272 return my_virtualness;
2275 /* Return a TREE_LIST containing all the non-hidden user-defined
2276 conversion functions for TYPE (and its base-classes). The
2277 TREE_VALUE of each node is the FUNCTION_DECL of the conversion
2278 function. The TREE_PURPOSE is the BINFO from which the conversion
2279 functions in this node were selected. This function is effectively
2280 performing a set of member lookups as lookup_fnfield does, but
2281 using the type being converted to as the unique key, rather than the
2285 lookup_conversions (tree type)
2287 tree convs, tpl_convs;
2288 tree list = NULL_TREE;
2290 complete_type (type);
2291 if (!TYPE_BINFO (type))
2294 lookup_conversions_r (TYPE_BINFO (type), 0, 0,
2295 NULL_TREE, NULL_TREE, NULL_TREE, NULL_TREE,
2296 &convs, &tpl_convs);
2298 /* Flatten the list-of-lists */
2299 for (; convs; convs = TREE_CHAIN (convs))
2303 for (probe = TREE_VALUE (convs); probe; probe = next)
2305 next = TREE_CHAIN (probe);
2307 TREE_CHAIN (probe) = list;
2312 for (; tpl_convs; tpl_convs = TREE_CHAIN (tpl_convs))
2316 for (probe = TREE_VALUE (tpl_convs); probe; probe = next)
2318 next = TREE_CHAIN (probe);
2320 TREE_CHAIN (probe) = list;
2328 /* Returns the binfo of the first direct or indirect virtual base derived
2329 from BINFO, or NULL if binfo is not via virtual. */
2332 binfo_from_vbase (tree binfo)
2334 for (; binfo; binfo = BINFO_INHERITANCE_CHAIN (binfo))
2336 if (BINFO_VIRTUAL_P (binfo))
2342 /* Returns the binfo of the first direct or indirect virtual base derived
2343 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2347 binfo_via_virtual (tree binfo, tree limit)
2349 for (; binfo && (!limit || !same_type_p (BINFO_TYPE (binfo), limit));
2350 binfo = BINFO_INHERITANCE_CHAIN (binfo))
2352 if (BINFO_VIRTUAL_P (binfo))
2358 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2359 Find the equivalent binfo within whatever graph HERE is located.
2360 This is the inverse of original_binfo. */
2363 copied_binfo (tree binfo, tree here)
2365 tree result = NULL_TREE;
2367 if (BINFO_VIRTUAL_P (binfo))
2371 for (t = here; BINFO_INHERITANCE_CHAIN (t);
2372 t = BINFO_INHERITANCE_CHAIN (t))
2375 result = binfo_for_vbase (BINFO_TYPE (binfo), BINFO_TYPE (t));
2377 else if (BINFO_INHERITANCE_CHAIN (binfo))
2383 cbinfo = copied_binfo (BINFO_INHERITANCE_CHAIN (binfo), here);
2384 for (ix = 0; BINFO_BASE_ITERATE (cbinfo, ix, base_binfo); ix++)
2385 if (BINFO_TYPE (base_binfo) == BINFO_TYPE (binfo))
2387 result = base_binfo;
2393 gcc_assert (BINFO_TYPE (here) == BINFO_TYPE (binfo));
2397 gcc_assert (result);
2402 binfo_for_vbase (tree base, tree t)
2408 for (vbases = CLASSTYPE_VBASECLASSES (t), ix = 0;
2409 VEC_iterate (tree, vbases, ix, binfo); ix++)
2410 if (BINFO_TYPE (binfo) == base)
2415 /* BINFO is some base binfo of HERE, within some other
2416 hierarchy. Return the equivalent binfo, but in the hierarchy
2417 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2418 is not a base binfo of HERE, returns NULL_TREE. */
2421 original_binfo (tree binfo, tree here)
2425 if (BINFO_TYPE (binfo) == BINFO_TYPE (here))
2427 else if (BINFO_VIRTUAL_P (binfo))
2428 result = (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here))
2429 ? binfo_for_vbase (BINFO_TYPE (binfo), BINFO_TYPE (here))
2431 else if (BINFO_INHERITANCE_CHAIN (binfo))
2435 base_binfos = original_binfo (BINFO_INHERITANCE_CHAIN (binfo), here);
2441 for (ix = 0; (base_binfo = BINFO_BASE_BINFO (base_binfos, ix)); ix++)
2442 if (BINFO_TYPE (base_binfo) == BINFO_TYPE (binfo))
2444 result = base_binfo;