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"
41 /* The class dominating the hierarchy. */
43 /* A pointer to a complete object of the indicated TYPE. */
48 static int is_subobject_of_p (tree
, tree
);
49 static base_kind
lookup_base_r (tree
, tree
, base_access
, bool, tree
*);
50 static int dynamic_cast_base_recurse (tree
, tree
, bool, tree
*);
51 static tree
dfs_debug_unmarkedp (tree
, int, void *);
52 static tree
dfs_debug_mark (tree
, void *);
53 static int check_hidden_convs (tree
, int, int, tree
, tree
, tree
);
54 static tree
split_conversions (tree
, tree
, tree
, tree
);
55 static int lookup_conversions_r (tree
, int, int,
56 tree
, tree
, tree
, tree
, tree
*, tree
*);
57 static int look_for_overrides_r (tree
, tree
);
58 static tree
lookup_field_queue_p (tree
, int, void *);
59 static int shared_member_p (tree
);
60 static tree
lookup_field_r (tree
, void *);
61 static tree
dfs_accessible_queue_p (tree
, int, void *);
62 static tree
dfs_accessible_p (tree
, void *);
63 static tree
dfs_access_in_type (tree
, void *);
64 static access_kind
access_in_type (tree
, tree
);
65 static int protected_accessible_p (tree
, tree
, tree
);
66 static int friend_accessible_p (tree
, tree
, tree
);
67 static int template_self_reference_p (tree
, tree
);
68 static tree
dfs_get_pure_virtuals (tree
, void *);
71 /* Variables for gathering statistics. */
72 #ifdef GATHER_STATISTICS
73 static int n_fields_searched
;
74 static int n_calls_lookup_field
, n_calls_lookup_field_1
;
75 static int n_calls_lookup_fnfields
, n_calls_lookup_fnfields_1
;
76 static int n_calls_get_base_type
;
77 static int n_outer_fields_searched
;
78 static int n_contexts_saved
;
79 #endif /* GATHER_STATISTICS */
82 /* Worker for lookup_base. BINFO is the binfo we are searching at,
83 BASE is the RECORD_TYPE we are searching for. ACCESS is the
84 required access checks. IS_VIRTUAL indicates if BINFO is morally
87 If BINFO is of the required type, then *BINFO_PTR is examined to
88 compare with any other instance of BASE we might have already
89 discovered. *BINFO_PTR is initialized and a base_kind return value
90 indicates what kind of base was located.
92 Otherwise BINFO's bases are searched. */
95 lookup_base_r (tree binfo
, tree base
, base_access access
,
96 bool is_virtual
, /* inside a virtual part */
101 base_kind found
= bk_not_base
;
103 if (same_type_p (BINFO_TYPE (binfo
), base
))
105 /* We have found a base. Check against what we have found
107 found
= bk_same_type
;
109 found
= bk_via_virtual
;
113 else if (binfo
!= *binfo_ptr
)
115 if (access
!= ba_any
)
117 else if (!is_virtual
)
118 /* Prefer a non-virtual base. */
126 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
130 bk
= lookup_base_r (base_binfo
, base
,
132 is_virtual
|| BINFO_VIRTUAL_P (base_binfo
),
138 if (access
!= ba_any
)
147 gcc_assert (found
== bk_not_base
);
152 if (found
!= bk_ambig
)
166 /* Returns true if type BASE is accessible in T. (BASE is known to be
167 a (possibly non-proper) base class of T.) */
170 accessible_base_p (tree t
, tree base
)
174 /* [class.access.base]
176 A base class is said to be accessible if an invented public
177 member of the base class is accessible.
179 If BASE is a non-proper base, this condition is trivially
181 if (same_type_p (t
, base
))
183 /* Rather than inventing a public member, we use the implicit
184 public typedef created in the scope of every class. */
185 decl
= TYPE_FIELDS (base
);
186 while (!DECL_SELF_REFERENCE_P (decl
))
187 decl
= TREE_CHAIN (decl
);
188 while (ANON_AGGR_TYPE_P (t
))
189 t
= TYPE_CONTEXT (t
);
190 return accessible_p (t
, decl
);
193 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
194 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
195 non-NULL, fill with information about what kind of base we
198 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
199 not set in ACCESS, then an error is issued and error_mark_node is
200 returned. If the ba_quiet bit is set, then no error is issued and
201 NULL_TREE is returned. */
204 lookup_base (tree t
, tree base
, base_access access
, base_kind
*kind_ptr
)
206 tree binfo
= NULL_TREE
; /* The binfo we've found so far. */
207 tree t_binfo
= NULL_TREE
;
210 if (t
== error_mark_node
|| base
== error_mark_node
)
213 *kind_ptr
= bk_not_base
;
214 return error_mark_node
;
216 gcc_assert (TYPE_P (base
));
225 t
= complete_type (TYPE_MAIN_VARIANT (t
));
226 t_binfo
= TYPE_BINFO (t
);
229 base
= complete_type (TYPE_MAIN_VARIANT (base
));
232 bk
= lookup_base_r (t_binfo
, base
, access
, 0, &binfo
);
236 /* Check that the base is unambiguous and accessible. */
237 if (access
!= ba_any
)
245 if (!(access
& ba_quiet
))
247 error ("`%T' is an ambiguous base of `%T'", base
, t
);
248 binfo
= error_mark_node
;
253 if ((access
& ~ba_quiet
) != ba_ignore
254 /* If BASE is incomplete, then BASE and TYPE are probably
255 the same, in which case BASE is accessible. If they
256 are not the same, then TYPE is invalid. In that case,
257 there's no need to issue another error here, and
258 there's no implicit typedef to use in the code that
259 follows, so we skip the check. */
260 && COMPLETE_TYPE_P (base
)
261 && !accessible_base_p (t
, base
))
263 if (!(access
& ba_quiet
))
265 error ("`%T' is an inaccessible base of `%T'", base
, t
);
266 binfo
= error_mark_node
;
270 bk
= bk_inaccessible
;
281 /* Worker function for get_dynamic_cast_base_type. */
284 dynamic_cast_base_recurse (tree subtype
, tree binfo
, bool is_via_virtual
,
287 VEC (tree
) *accesses
;
292 if (BINFO_TYPE (binfo
) == subtype
)
298 *offset_ptr
= BINFO_OFFSET (binfo
);
303 accesses
= BINFO_BASE_ACCESSES (binfo
);
304 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
306 tree base_access
= VEC_index (tree
, accesses
, i
);
309 if (base_access
!= access_public_node
)
311 rval
= dynamic_cast_base_recurse
312 (subtype
, base_binfo
,
313 is_via_virtual
|| BINFO_VIRTUAL_P (base_binfo
), offset_ptr
);
317 worst
= worst
>= 0 ? -3 : worst
;
320 else if (rval
== -3 && worst
!= -1)
326 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
327 started from is related to the required TARGET type, in order to optimize
328 the inheritance graph search. This information is independent of the
329 current context, and ignores private paths, hence get_base_distance is
330 inappropriate. Return a TREE specifying the base offset, BOFF.
331 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
332 and there are no public virtual SUBTYPE bases.
333 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
334 BOFF == -2, SUBTYPE is not a public base.
335 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
338 get_dynamic_cast_base_type (tree subtype
, tree target
)
340 tree offset
= NULL_TREE
;
341 int boff
= dynamic_cast_base_recurse (subtype
, TYPE_BINFO (target
),
346 offset
= ssize_int (boff
);
350 /* Search for a member with name NAME in a multiple inheritance
351 lattice specified by TYPE. If it does not exist, return NULL_TREE.
352 If the member is ambiguously referenced, return `error_mark_node'.
353 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
354 true, type declarations are preferred. */
356 /* Do a 1-level search for NAME as a member of TYPE. The caller must
357 figure out whether it can access this field. (Since it is only one
358 level, this is reasonable.) */
361 lookup_field_1 (tree type
, tree name
, bool want_type
)
365 if (TREE_CODE (type
) == TEMPLATE_TYPE_PARM
366 || TREE_CODE (type
) == BOUND_TEMPLATE_TEMPLATE_PARM
367 || TREE_CODE (type
) == TYPENAME_TYPE
)
368 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
369 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
370 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
371 the code often worked even when we treated the index as a list
373 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
377 && DECL_LANG_SPECIFIC (TYPE_NAME (type
))
378 && DECL_SORTED_FIELDS (TYPE_NAME (type
)))
380 tree
*fields
= &DECL_SORTED_FIELDS (TYPE_NAME (type
))->elts
[0];
381 int lo
= 0, hi
= DECL_SORTED_FIELDS (TYPE_NAME (type
))->len
;
388 #ifdef GATHER_STATISTICS
390 #endif /* GATHER_STATISTICS */
392 if (DECL_NAME (fields
[i
]) > name
)
394 else if (DECL_NAME (fields
[i
]) < name
)
400 /* We might have a nested class and a field with the
401 same name; we sorted them appropriately via
402 field_decl_cmp, so just look for the first or last
403 field with this name. */
408 while (i
>= lo
&& DECL_NAME (fields
[i
]) == name
);
409 if (TREE_CODE (field
) != TYPE_DECL
410 && !DECL_CLASS_TEMPLATE_P (field
))
417 while (i
< hi
&& DECL_NAME (fields
[i
]) == name
);
425 field
= TYPE_FIELDS (type
);
427 #ifdef GATHER_STATISTICS
428 n_calls_lookup_field_1
++;
429 #endif /* GATHER_STATISTICS */
430 for (field
= TYPE_FIELDS (type
); field
; field
= TREE_CHAIN (field
))
432 #ifdef GATHER_STATISTICS
434 #endif /* GATHER_STATISTICS */
435 gcc_assert (DECL_P (field
));
436 if (DECL_NAME (field
) == NULL_TREE
437 && ANON_AGGR_TYPE_P (TREE_TYPE (field
)))
439 tree temp
= lookup_field_1 (TREE_TYPE (field
), name
, want_type
);
443 if (TREE_CODE (field
) == USING_DECL
)
445 /* We generally treat class-scope using-declarations as
446 ARM-style access specifications, because support for the
447 ISO semantics has not been implemented. So, in general,
448 there's no reason to return a USING_DECL, and the rest of
449 the compiler cannot handle that. Once the class is
450 defined, USING_DECLs are purged from TYPE_FIELDS; see
451 handle_using_decl. However, we make special efforts to
452 make using-declarations in template classes work
454 if (CLASSTYPE_TEMPLATE_INFO (type
)
455 && !CLASSTYPE_USE_TEMPLATE (type
)
456 && !TREE_TYPE (field
))
462 if (DECL_NAME (field
) == name
464 || TREE_CODE (field
) == TYPE_DECL
465 || DECL_CLASS_TEMPLATE_P (field
)))
469 if (name
== vptr_identifier
)
471 /* Give the user what s/he thinks s/he wants. */
472 if (TYPE_POLYMORPHIC_P (type
))
473 return TYPE_VFIELD (type
);
478 /* There are a number of cases we need to be aware of here:
479 current_class_type current_function_decl
486 Those last two make life interesting. If we're in a function which is
487 itself inside a class, we need decls to go into the fn's decls (our
488 second case below). But if we're in a class and the class itself is
489 inside a function, we need decls to go into the decls for the class. To
490 achieve this last goal, we must see if, when both current_class_ptr and
491 current_function_decl are set, the class was declared inside that
492 function. If so, we know to put the decls into the class's scope. */
497 if (current_function_decl
== NULL_TREE
)
498 return current_class_type
;
499 if (current_class_type
== NULL_TREE
)
500 return current_function_decl
;
501 if ((DECL_FUNCTION_MEMBER_P (current_function_decl
)
502 && same_type_p (DECL_CONTEXT (current_function_decl
),
504 || (DECL_FRIEND_CONTEXT (current_function_decl
)
505 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl
),
506 current_class_type
)))
507 return current_function_decl
;
509 return current_class_type
;
512 /* Returns nonzero if we are currently in a function scope. Note
513 that this function returns zero if we are within a local class, but
514 not within a member function body of the local class. */
517 at_function_scope_p (void)
519 tree cs
= current_scope ();
520 return cs
&& TREE_CODE (cs
) == FUNCTION_DECL
;
523 /* Returns true if the innermost active scope is a class scope. */
526 at_class_scope_p (void)
528 tree cs
= current_scope ();
529 return cs
&& TYPE_P (cs
);
532 /* Returns true if the innermost active scope is a namespace scope. */
535 at_namespace_scope_p (void)
537 /* We are in a namespace scope if we are not it a class scope or a
539 return !current_scope();
542 /* Return the scope of DECL, as appropriate when doing name-lookup. */
545 context_for_name_lookup (tree decl
)
549 For the purposes of name lookup, after the anonymous union
550 definition, the members of the anonymous union are considered to
551 have been defined in the scope in which the anonymous union is
553 tree context
= DECL_CONTEXT (decl
);
555 while (context
&& TYPE_P (context
) && ANON_AGGR_TYPE_P (context
))
556 context
= TYPE_CONTEXT (context
);
558 context
= global_namespace
;
563 /* The accessibility routines use BINFO_ACCESS for scratch space
564 during the computation of the accessibility of some declaration. */
566 #define BINFO_ACCESS(NODE) \
567 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
569 /* Set the access associated with NODE to ACCESS. */
571 #define SET_BINFO_ACCESS(NODE, ACCESS) \
572 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
573 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
575 /* Called from access_in_type via dfs_walk. Calculate the access to
576 DATA (which is really a DECL) in BINFO. */
579 dfs_access_in_type (tree binfo
, void *data
)
581 tree decl
= (tree
) data
;
582 tree type
= BINFO_TYPE (binfo
);
583 access_kind access
= ak_none
;
585 if (context_for_name_lookup (decl
) == type
)
587 /* If we have descended to the scope of DECL, just note the
588 appropriate access. */
589 if (TREE_PRIVATE (decl
))
591 else if (TREE_PROTECTED (decl
))
592 access
= ak_protected
;
598 /* First, check for an access-declaration that gives us more
599 access to the DECL. The CONST_DECL for an enumeration
600 constant will not have DECL_LANG_SPECIFIC, and thus no
602 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
))
604 tree decl_access
= purpose_member (type
, DECL_ACCESS (decl
));
608 decl_access
= TREE_VALUE (decl_access
);
610 if (decl_access
== access_public_node
)
612 else if (decl_access
== access_protected_node
)
613 access
= ak_protected
;
614 else if (decl_access
== access_private_node
)
625 VEC (tree
) *accesses
;
627 /* Otherwise, scan our baseclasses, and pick the most favorable
629 accesses
= BINFO_BASE_ACCESSES (binfo
);
630 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
632 tree base_access
= VEC_index (tree
, accesses
, i
);
633 access_kind base_access_now
= BINFO_ACCESS (base_binfo
);
635 if (base_access_now
== ak_none
|| base_access_now
== ak_private
)
636 /* If it was not accessible in the base, or only
637 accessible as a private member, we can't access it
639 base_access_now
= ak_none
;
640 else if (base_access
== access_protected_node
)
641 /* Public and protected members in the base become
643 base_access_now
= ak_protected
;
644 else if (base_access
== access_private_node
)
645 /* Public and protected members in the base become
647 base_access_now
= ak_private
;
649 /* See if the new access, via this base, gives more
650 access than our previous best access. */
651 if (base_access_now
!= ak_none
652 && (access
== ak_none
|| base_access_now
< access
))
654 access
= base_access_now
;
656 /* If the new access is public, we can't do better. */
657 if (access
== ak_public
)
664 /* Note the access to DECL in TYPE. */
665 SET_BINFO_ACCESS (binfo
, access
);
667 /* Mark TYPE as visited so that if we reach it again we do not
668 duplicate our efforts here. */
669 BINFO_MARKED (binfo
) = 1;
674 /* Return the access to DECL in TYPE. */
677 access_in_type (tree type
, tree decl
)
679 tree binfo
= TYPE_BINFO (type
);
681 /* We must take into account
685 If a name can be reached by several paths through a multiple
686 inheritance graph, the access is that of the path that gives
689 The algorithm we use is to make a post-order depth-first traversal
690 of the base-class hierarchy. As we come up the tree, we annotate
691 each node with the most lenient access. */
692 dfs_walk_real (binfo
, 0, dfs_access_in_type
, unmarkedp
, decl
);
693 dfs_walk (binfo
, dfs_unmark
, markedp
, 0);
695 return BINFO_ACCESS (binfo
);
698 /* Called from accessible_p via dfs_walk. */
701 dfs_accessible_queue_p (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
703 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
705 if (BINFO_MARKED (binfo
))
708 /* If this class is inherited via private or protected inheritance,
709 then we can't see it, unless we are a friend of the derived class. */
710 if (BINFO_BASE_ACCESS (derived
, ix
) != access_public_node
711 && !is_friend (BINFO_TYPE (derived
), current_scope ()))
717 /* Called from accessible_p via dfs_walk. */
720 dfs_accessible_p (tree binfo
, void *data ATTRIBUTE_UNUSED
)
724 BINFO_MARKED (binfo
) = 1;
725 access
= BINFO_ACCESS (binfo
);
726 if (access
!= ak_none
727 && is_friend (BINFO_TYPE (binfo
), current_scope ()))
733 /* Returns nonzero if it is OK to access DECL through an object
734 indicated by BINFO in the context of DERIVED. */
737 protected_accessible_p (tree decl
, tree derived
, tree binfo
)
741 /* We're checking this clause from [class.access.base]
743 m as a member of N is protected, and the reference occurs in a
744 member or friend of class N, or in a member or friend of a
745 class P derived from N, where m as a member of P is private or
748 Here DERIVED is a possible P and DECL is m. accessible_p will
749 iterate over various values of N, but the access to m in DERIVED
752 Note that I believe that the passage above is wrong, and should read
753 "...is private or protected or public"; otherwise you get bizarre results
754 whereby a public using-decl can prevent you from accessing a protected
755 member of a base. (jason 2000/02/28) */
757 /* If DERIVED isn't derived from m's class, then it can't be a P. */
758 if (!DERIVED_FROM_P (context_for_name_lookup (decl
), derived
))
761 access
= access_in_type (derived
, decl
);
763 /* If m is inaccessible in DERIVED, then it's not a P. */
764 if (access
== ak_none
)
769 When a friend or a member function of a derived class references
770 a protected nonstatic member of a base class, an access check
771 applies in addition to those described earlier in clause
772 _class.access_) Except when forming a pointer to member
773 (_expr.unary.op_), the access must be through a pointer to,
774 reference to, or object of the derived class itself (or any class
775 derived from that class) (_expr.ref_). If the access is to form
776 a pointer to member, the nested-name-specifier shall name the
777 derived class (or any class derived from that class). */
778 if (DECL_NONSTATIC_MEMBER_P (decl
))
780 /* We can tell through what the reference is occurring by
781 chasing BINFO up to the root. */
783 while (BINFO_INHERITANCE_CHAIN (t
))
784 t
= BINFO_INHERITANCE_CHAIN (t
);
786 if (!DERIVED_FROM_P (derived
, BINFO_TYPE (t
)))
793 /* Returns nonzero if SCOPE is a friend of a type which would be able
794 to access DECL through the object indicated by BINFO. */
797 friend_accessible_p (tree scope
, tree decl
, tree binfo
)
799 tree befriending_classes
;
805 if (TREE_CODE (scope
) == FUNCTION_DECL
806 || DECL_FUNCTION_TEMPLATE_P (scope
))
807 befriending_classes
= DECL_BEFRIENDING_CLASSES (scope
);
808 else if (TYPE_P (scope
))
809 befriending_classes
= CLASSTYPE_BEFRIENDING_CLASSES (scope
);
813 for (t
= befriending_classes
; t
; t
= TREE_CHAIN (t
))
814 if (protected_accessible_p (decl
, TREE_VALUE (t
), binfo
))
817 /* Nested classes are implicitly friends of their enclosing types, as
818 per core issue 45 (this is a change from the standard). */
820 for (t
= TYPE_CONTEXT (scope
); t
&& TYPE_P (t
); t
= TYPE_CONTEXT (t
))
821 if (protected_accessible_p (decl
, t
, binfo
))
824 if (TREE_CODE (scope
) == FUNCTION_DECL
825 || DECL_FUNCTION_TEMPLATE_P (scope
))
827 /* Perhaps this SCOPE is a member of a class which is a
829 if (DECL_CLASS_SCOPE_P (decl
)
830 && friend_accessible_p (DECL_CONTEXT (scope
), decl
, binfo
))
833 /* Or an instantiation of something which is a friend. */
834 if (DECL_TEMPLATE_INFO (scope
))
837 /* Increment processing_template_decl to make sure that
838 dependent_type_p works correctly. */
839 ++processing_template_decl
;
840 ret
= friend_accessible_p (DECL_TI_TEMPLATE (scope
), decl
, binfo
);
841 --processing_template_decl
;
845 else if (CLASSTYPE_TEMPLATE_INFO (scope
))
848 /* Increment processing_template_decl to make sure that
849 dependent_type_p works correctly. */
850 ++processing_template_decl
;
851 ret
= friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope
), decl
, binfo
);
852 --processing_template_decl
;
859 /* DECL is a declaration from a base class of TYPE, which was the
860 class used to name DECL. Return nonzero if, in the current
861 context, DECL is accessible. If TYPE is actually a BINFO node,
862 then we can tell in what context the access is occurring by looking
863 at the most derived class along the path indicated by BINFO. */
866 accessible_p (tree type
, tree decl
)
873 /* Nonzero if it's OK to access DECL if it has protected
874 accessibility in TYPE. */
875 int protected_ok
= 0;
877 /* If this declaration is in a block or namespace scope, there's no
879 if (!TYPE_P (context_for_name_lookup (decl
)))
882 /* There is no need to perform access checks inside a thunk. */
883 scope
= current_scope ();
884 if (scope
&& DECL_THUNK_P (scope
))
887 /* In a template declaration, we cannot be sure whether the
888 particular specialization that is instantiated will be a friend
889 or not. Therefore, all access checks are deferred until
891 if (processing_template_decl
)
897 type
= BINFO_TYPE (type
);
900 binfo
= TYPE_BINFO (type
);
902 /* [class.access.base]
904 A member m is accessible when named in class N if
906 --m as a member of N is public, or
908 --m as a member of N is private, and the reference occurs in a
909 member or friend of class N, or
911 --m as a member of N is protected, and the reference occurs in a
912 member or friend of class N, or in a member or friend of a
913 class P derived from N, where m as a member of P is private or
916 --there exists a base class B of N that is accessible at the point
917 of reference, and m is accessible when named in class B.
919 We walk the base class hierarchy, checking these conditions. */
921 /* Figure out where the reference is occurring. Check to see if
922 DECL is private or protected in this scope, since that will
923 determine whether protected access is allowed. */
924 if (current_class_type
)
925 protected_ok
= protected_accessible_p (decl
, current_class_type
, binfo
);
927 /* Now, loop through the classes of which we are a friend. */
929 protected_ok
= friend_accessible_p (scope
, decl
, binfo
);
931 /* Standardize the binfo that access_in_type will use. We don't
932 need to know what path was chosen from this point onwards. */
933 binfo
= TYPE_BINFO (type
);
935 /* Compute the accessibility of DECL in the class hierarchy
936 dominated by type. */
937 access
= access_in_type (type
, decl
);
938 if (access
== ak_public
939 || (access
== ak_protected
&& protected_ok
))
943 /* Walk the hierarchy again, looking for a base class that allows
945 t
= dfs_walk (binfo
, dfs_accessible_p
, dfs_accessible_queue_p
, 0);
946 /* Clear any mark bits. Note that we have to walk the whole tree
947 here, since we have aborted the previous walk from some point
949 dfs_walk (binfo
, dfs_unmark
, 0, 0);
951 return t
!= NULL_TREE
;
955 struct lookup_field_info
{
956 /* The type in which we're looking. */
958 /* The name of the field for which we're looking. */
960 /* If non-NULL, the current result of the lookup. */
962 /* The path to RVAL. */
964 /* If non-NULL, the lookup was ambiguous, and this is a list of the
967 /* If nonzero, we are looking for types, not data members. */
969 /* If something went wrong, a message indicating what. */
973 /* Returns nonzero if BINFO is not hidden by the value found by the
974 lookup so far. If BINFO is hidden, then there's no need to look in
975 it. DATA is really a struct lookup_field_info. Called from
976 lookup_field via breadth_first_search. */
979 lookup_field_queue_p (tree derived
, int ix
, void *data
)
981 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
982 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
984 /* Don't look for constructors or destructors in base classes. */
985 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi
->name
))
988 /* If this base class is hidden by the best-known value so far, we
989 don't need to look. */
990 if (lfi
->rval_binfo
&& derived
== lfi
->rval_binfo
)
993 /* If this is a dependent base, don't look in it. */
994 if (BINFO_DEPENDENT_BASE_P (binfo
))
1000 /* Within the scope of a template class, you can refer to the to the
1001 current specialization with the name of the template itself. For
1004 template <typename T> struct S { S* sp; }
1006 Returns nonzero if DECL is such a declaration in a class TYPE. */
1009 template_self_reference_p (tree type
, tree decl
)
1011 return (CLASSTYPE_USE_TEMPLATE (type
)
1012 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type
))
1013 && TREE_CODE (decl
) == TYPE_DECL
1014 && DECL_ARTIFICIAL (decl
)
1015 && DECL_NAME (decl
) == constructor_name (type
));
1018 /* Nonzero for a class member means that it is shared between all objects
1021 [class.member.lookup]:If the resulting set of declarations are not all
1022 from sub-objects of the same type, or the set has a nonstatic member
1023 and includes members from distinct sub-objects, there is an ambiguity
1024 and the program is ill-formed.
1026 This function checks that T contains no nonstatic members. */
1029 shared_member_p (tree t
)
1031 if (TREE_CODE (t
) == VAR_DECL
|| TREE_CODE (t
) == TYPE_DECL \
1032 || TREE_CODE (t
) == CONST_DECL
)
1034 if (is_overloaded_fn (t
))
1036 for (; t
; t
= OVL_NEXT (t
))
1038 tree fn
= OVL_CURRENT (t
);
1039 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn
))
1047 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1048 found as a base class and sub-object of the object denoted by
1052 is_subobject_of_p (tree parent
, tree binfo
)
1056 for (probe
= parent
; probe
; probe
= BINFO_INHERITANCE_CHAIN (probe
))
1060 if (BINFO_VIRTUAL_P (probe
))
1061 return (binfo_for_vbase (BINFO_TYPE (probe
), BINFO_TYPE (binfo
))
1067 /* DATA is really a struct lookup_field_info. Look for a field with
1068 the name indicated there in BINFO. If this function returns a
1069 non-NULL value it is the result of the lookup. Called from
1070 lookup_field via breadth_first_search. */
1073 lookup_field_r (tree binfo
, void *data
)
1075 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
1076 tree type
= BINFO_TYPE (binfo
);
1077 tree nval
= NULL_TREE
;
1079 /* First, look for a function. There can't be a function and a data
1080 member with the same name, and if there's a function and a type
1081 with the same name, the type is hidden by the function. */
1082 if (!lfi
->want_type
)
1084 int idx
= lookup_fnfields_1 (type
, lfi
->name
);
1086 nval
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), idx
);
1090 /* Look for a data member or type. */
1091 nval
= lookup_field_1 (type
, lfi
->name
, lfi
->want_type
);
1093 /* If there is no declaration with the indicated name in this type,
1094 then there's nothing to do. */
1098 /* If we're looking up a type (as with an elaborated type specifier)
1099 we ignore all non-types we find. */
1100 if (lfi
->want_type
&& TREE_CODE (nval
) != TYPE_DECL
1101 && !DECL_CLASS_TEMPLATE_P (nval
))
1103 if (lfi
->name
== TYPE_IDENTIFIER (type
))
1105 /* If the aggregate has no user defined constructors, we allow
1106 it to have fields with the same name as the enclosing type.
1107 If we are looking for that name, find the corresponding
1109 for (nval
= TREE_CHAIN (nval
); nval
; nval
= TREE_CHAIN (nval
))
1110 if (DECL_NAME (nval
) == lfi
->name
1111 && TREE_CODE (nval
) == TYPE_DECL
)
1116 if (!nval
&& CLASSTYPE_NESTED_UTDS (type
) != NULL
)
1118 binding_entry e
= binding_table_find (CLASSTYPE_NESTED_UTDS (type
),
1121 nval
= TYPE_MAIN_DECL (e
->type
);
1127 /* You must name a template base class with a template-id. */
1128 if (!same_type_p (type
, lfi
->type
)
1129 && template_self_reference_p (type
, nval
))
1132 /* If the lookup already found a match, and the new value doesn't
1133 hide the old one, we might have an ambiguity. */
1135 && !is_subobject_of_p (lfi
->rval_binfo
, binfo
))
1138 if (nval
== lfi
->rval
&& shared_member_p (nval
))
1139 /* The two things are really the same. */
1141 else if (is_subobject_of_p (binfo
, lfi
->rval_binfo
))
1142 /* The previous value hides the new one. */
1146 /* We have a real ambiguity. We keep a chain of all the
1148 if (!lfi
->ambiguous
&& lfi
->rval
)
1150 /* This is the first time we noticed an ambiguity. Add
1151 what we previously thought was a reasonable candidate
1153 lfi
->ambiguous
= tree_cons (NULL_TREE
, lfi
->rval
, NULL_TREE
);
1154 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1157 /* Add the new value. */
1158 lfi
->ambiguous
= tree_cons (NULL_TREE
, nval
, lfi
->ambiguous
);
1159 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1160 lfi
->errstr
= "request for member `%D' is ambiguous";
1166 lfi
->rval_binfo
= binfo
;
1172 /* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1173 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1174 FUNCTIONS, and OPTYPE respectively. */
1177 build_baselink (tree binfo
, tree access_binfo
, tree functions
, tree optype
)
1181 gcc_assert (TREE_CODE (functions
) == FUNCTION_DECL
1182 || TREE_CODE (functions
) == TEMPLATE_DECL
1183 || TREE_CODE (functions
) == TEMPLATE_ID_EXPR
1184 || TREE_CODE (functions
) == OVERLOAD
);
1185 gcc_assert (!optype
|| TYPE_P (optype
));
1186 gcc_assert (TREE_TYPE (functions
));
1188 baselink
= make_node (BASELINK
);
1189 TREE_TYPE (baselink
) = TREE_TYPE (functions
);
1190 BASELINK_BINFO (baselink
) = binfo
;
1191 BASELINK_ACCESS_BINFO (baselink
) = access_binfo
;
1192 BASELINK_FUNCTIONS (baselink
) = functions
;
1193 BASELINK_OPTYPE (baselink
) = optype
;
1198 /* Look for a member named NAME in an inheritance lattice dominated by
1199 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1200 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1201 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1202 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1203 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1204 TREE_VALUEs are the list of ambiguous candidates.
1206 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1208 If nothing can be found return NULL_TREE and do not issue an error. */
1211 lookup_member (tree xbasetype
, tree name
, int protect
, bool want_type
)
1213 tree rval
, rval_binfo
= NULL_TREE
;
1214 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1215 struct lookup_field_info lfi
;
1217 /* rval_binfo is the binfo associated with the found member, note,
1218 this can be set with useful information, even when rval is not
1219 set, because it must deal with ALL members, not just non-function
1220 members. It is used for ambiguity checking and the hidden
1221 checks. Whereas rval is only set if a proper (not hidden)
1222 non-function member is found. */
1224 const char *errstr
= 0;
1226 gcc_assert (TREE_CODE (name
) == IDENTIFIER_NODE
);
1228 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1230 type
= BINFO_TYPE (xbasetype
);
1231 basetype_path
= xbasetype
;
1235 gcc_assert (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype
)));
1237 xbasetype
= NULL_TREE
;
1240 type
= complete_type (type
);
1242 basetype_path
= TYPE_BINFO (type
);
1247 #ifdef GATHER_STATISTICS
1248 n_calls_lookup_field
++;
1249 #endif /* GATHER_STATISTICS */
1251 memset (&lfi
, 0, sizeof (lfi
));
1254 lfi
.want_type
= want_type
;
1255 dfs_walk_real (basetype_path
, &lookup_field_r
, 0,
1256 &lookup_field_queue_p
, &lfi
);
1258 rval_binfo
= lfi
.rval_binfo
;
1260 type
= BINFO_TYPE (rval_binfo
);
1261 errstr
= lfi
.errstr
;
1263 /* If we are not interested in ambiguities, don't report them;
1264 just return NULL_TREE. */
1265 if (!protect
&& lfi
.ambiguous
)
1271 return lfi
.ambiguous
;
1278 In the case of overloaded function names, access control is
1279 applied to the function selected by overloaded resolution. */
1280 if (rval
&& protect
&& !is_overloaded_fn (rval
))
1281 perform_or_defer_access_check (basetype_path
, rval
);
1283 if (errstr
&& protect
)
1285 error (errstr
, name
, type
);
1287 print_candidates (lfi
.ambiguous
);
1288 rval
= error_mark_node
;
1291 if (rval
&& is_overloaded_fn (rval
))
1292 rval
= build_baselink (rval_binfo
, basetype_path
, rval
,
1293 (IDENTIFIER_TYPENAME_P (name
)
1294 ? TREE_TYPE (name
): NULL_TREE
));
1298 /* Like lookup_member, except that if we find a function member we
1299 return NULL_TREE. */
1302 lookup_field (tree xbasetype
, tree name
, int protect
, bool want_type
)
1304 tree rval
= lookup_member (xbasetype
, name
, protect
, want_type
);
1306 /* Ignore functions, but propagate the ambiguity list. */
1307 if (!error_operand_p (rval
)
1308 && (rval
&& BASELINK_P (rval
)))
1314 /* Like lookup_member, except that if we find a non-function member we
1315 return NULL_TREE. */
1318 lookup_fnfields (tree xbasetype
, tree name
, int protect
)
1320 tree rval
= lookup_member (xbasetype
, name
, protect
, /*want_type=*/false);
1322 /* Ignore non-functions, but propagate the ambiguity list. */
1323 if (!error_operand_p (rval
)
1324 && (rval
&& !BASELINK_P (rval
)))
1330 /* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE
1331 corresponding to "operator TYPE ()", or -1 if there is no such
1332 operator. Only CLASS_TYPE itself is searched; this routine does
1333 not scan the base classes of CLASS_TYPE. */
1336 lookup_conversion_operator (tree class_type
, tree type
)
1340 if (TYPE_HAS_CONVERSION (class_type
))
1344 VEC(tree
) *methods
= CLASSTYPE_METHOD_VEC (class_type
);
1346 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1347 VEC_iterate (tree
, methods
, i
, fn
); ++i
)
1349 /* All the conversion operators come near the beginning of
1350 the class. Therefore, if FN is not a conversion
1351 operator, there is no matching conversion operator in
1353 fn
= OVL_CURRENT (fn
);
1354 if (!DECL_CONV_FN_P (fn
))
1357 if (TREE_CODE (fn
) == TEMPLATE_DECL
)
1358 /* All the templated conversion functions are on the same
1359 slot, so remember it. */
1361 else if (same_type_p (DECL_CONV_FN_TYPE (fn
), type
))
1369 /* TYPE is a class type. Return the index of the fields within
1370 the method vector with name NAME, or -1 is no such field exists. */
1373 lookup_fnfields_1 (tree type
, tree name
)
1375 VEC(tree
) *method_vec
;
1380 if (!CLASS_TYPE_P (type
))
1383 if (COMPLETE_TYPE_P (type
))
1385 if ((name
== ctor_identifier
1386 || name
== base_ctor_identifier
1387 || name
== complete_ctor_identifier
))
1389 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type
))
1390 lazily_declare_fn (sfk_constructor
, type
);
1391 if (CLASSTYPE_LAZY_COPY_CTOR (type
))
1392 lazily_declare_fn (sfk_copy_constructor
, type
);
1394 else if (name
== ansi_assopname(NOP_EXPR
)
1395 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type
))
1396 lazily_declare_fn (sfk_assignment_operator
, type
);
1399 method_vec
= CLASSTYPE_METHOD_VEC (type
);
1403 #ifdef GATHER_STATISTICS
1404 n_calls_lookup_fnfields_1
++;
1405 #endif /* GATHER_STATISTICS */
1407 /* Constructors are first... */
1408 if (name
== ctor_identifier
)
1410 fn
= CLASSTYPE_CONSTRUCTORS (type
);
1411 return fn
? CLASSTYPE_CONSTRUCTOR_SLOT
: -1;
1413 /* and destructors are second. */
1414 if (name
== dtor_identifier
)
1416 fn
= CLASSTYPE_DESTRUCTORS (type
);
1417 return fn
? CLASSTYPE_DESTRUCTOR_SLOT
: -1;
1419 if (IDENTIFIER_TYPENAME_P (name
))
1420 return lookup_conversion_operator (type
, TREE_TYPE (name
));
1422 /* Skip the conversion operators. */
1423 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1424 VEC_iterate (tree
, method_vec
, i
, fn
);
1426 if (!DECL_CONV_FN_P (OVL_CURRENT (fn
)))
1429 /* If the type is complete, use binary search. */
1430 if (COMPLETE_TYPE_P (type
))
1436 hi
= VEC_length (tree
, method_vec
);
1441 #ifdef GATHER_STATISTICS
1442 n_outer_fields_searched
++;
1443 #endif /* GATHER_STATISTICS */
1445 tmp
= VEC_index (tree
, method_vec
, i
);
1446 tmp
= DECL_NAME (OVL_CURRENT (tmp
));
1449 else if (tmp
< name
)
1456 for (; VEC_iterate (tree
, method_vec
, i
, fn
); ++i
)
1458 #ifdef GATHER_STATISTICS
1459 n_outer_fields_searched
++;
1460 #endif /* GATHER_STATISTICS */
1461 if (DECL_NAME (OVL_CURRENT (fn
)) == name
)
1468 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1469 the class or namespace used to qualify the name. CONTEXT_CLASS is
1470 the class corresponding to the object in which DECL will be used.
1471 Return a possibly modified version of DECL that takes into account
1474 In particular, consider an expression like `B::m' in the context of
1475 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1476 then the most derived class indicated by the BASELINK_BINFO will be
1477 `B', not `D'. This function makes that adjustment. */
1480 adjust_result_of_qualified_name_lookup (tree decl
,
1481 tree qualifying_scope
,
1484 if (context_class
&& CLASS_TYPE_P (qualifying_scope
)
1485 && DERIVED_FROM_P (qualifying_scope
, context_class
)
1486 && BASELINK_P (decl
))
1490 gcc_assert (CLASS_TYPE_P (context_class
));
1492 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1493 Because we do not yet know which function will be chosen by
1494 overload resolution, we cannot yet check either accessibility
1495 or ambiguity -- in either case, the choice of a static member
1496 function might make the usage valid. */
1497 base
= lookup_base (context_class
, qualifying_scope
,
1498 ba_ignore
| ba_quiet
, NULL
);
1501 BASELINK_ACCESS_BINFO (decl
) = base
;
1502 BASELINK_BINFO (decl
)
1503 = lookup_base (base
, BINFO_TYPE (BASELINK_BINFO (decl
)),
1504 ba_ignore
| ba_quiet
,
1513 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
1514 PREFN is called in preorder, while POSTFN is called in postorder.
1515 If they ever returns a non-NULL value, that value is immediately
1516 returned and the walk is terminated. Both PREFN and POSTFN can be
1517 NULL. At each node, PREFN and POSTFN are passed the binfo to
1518 examine. Before each base-binfo of BINFO is walked, QFN is called.
1519 If the value returned is nonzero, the base-binfo is walked;
1520 otherwise it is not. If QFN is NULL, it is treated as a function
1521 which always returns 1. All callbacks are passed DATA whenever
1525 dfs_walk_real (tree binfo
,
1526 tree (*prefn
) (tree
, void *),
1527 tree (*postfn
) (tree
, void *),
1528 tree (*qfn
) (tree
, int, void *),
1533 tree rval
= NULL_TREE
;
1535 /* Call the pre-order walking function. */
1538 rval
= (*prefn
) (binfo
, data
);
1543 /* Process the basetypes. */
1544 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1548 base_binfo
= (*qfn
) (binfo
, i
, data
);
1552 rval
= dfs_walk_real (base_binfo
, prefn
, postfn
, qfn
, data
);
1557 /* Call the post-order walking function. */
1559 rval
= (*postfn
) (binfo
, data
);
1564 /* Exactly like dfs_walk_real, except that there is no pre-order
1565 function call and FN is called in post-order. */
1568 dfs_walk (tree binfo
,
1569 tree (*fn
) (tree
, void *),
1570 tree (*qfn
) (tree
, int, void *),
1573 return dfs_walk_real (binfo
, 0, fn
, qfn
, data
);
1576 /* Check that virtual overrider OVERRIDER is acceptable for base function
1577 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1580 check_final_overrider (tree overrider
, tree basefn
)
1582 tree over_type
= TREE_TYPE (overrider
);
1583 tree base_type
= TREE_TYPE (basefn
);
1584 tree over_return
= TREE_TYPE (over_type
);
1585 tree base_return
= TREE_TYPE (base_type
);
1586 tree over_throw
= TYPE_RAISES_EXCEPTIONS (over_type
);
1587 tree base_throw
= TYPE_RAISES_EXCEPTIONS (base_type
);
1590 if (DECL_INVALID_OVERRIDER_P (overrider
))
1593 if (same_type_p (base_return
, over_return
))
1595 else if ((CLASS_TYPE_P (over_return
) && CLASS_TYPE_P (base_return
))
1596 || (TREE_CODE (base_return
) == TREE_CODE (over_return
)
1597 && POINTER_TYPE_P (base_return
)))
1599 /* Potentially covariant. */
1600 unsigned base_quals
, over_quals
;
1602 fail
= !POINTER_TYPE_P (base_return
);
1605 fail
= cp_type_quals (base_return
) != cp_type_quals (over_return
);
1607 base_return
= TREE_TYPE (base_return
);
1608 over_return
= TREE_TYPE (over_return
);
1610 base_quals
= cp_type_quals (base_return
);
1611 over_quals
= cp_type_quals (over_return
);
1613 if ((base_quals
& over_quals
) != over_quals
)
1616 if (CLASS_TYPE_P (base_return
) && CLASS_TYPE_P (over_return
))
1618 tree binfo
= lookup_base (over_return
, base_return
,
1619 ba_check
| ba_quiet
, NULL
);
1625 && can_convert (TREE_TYPE (base_type
), TREE_TYPE (over_type
)))
1626 /* GNU extension, allow trivial pointer conversions such as
1627 converting to void *, or qualification conversion. */
1629 /* can_convert will permit user defined conversion from a
1630 (reference to) class type. We must reject them. */
1631 over_return
= non_reference (TREE_TYPE (over_type
));
1632 if (CLASS_TYPE_P (over_return
))
1646 cp_error_at ("invalid covariant return type for `%#D'", overrider
);
1647 cp_error_at (" overriding `%#D'", basefn
);
1651 cp_error_at ("conflicting return type specified for `%#D'",
1653 cp_error_at (" overriding `%#D'", basefn
);
1655 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1659 /* Check throw specifier is at least as strict. */
1660 if (!comp_except_specs (base_throw
, over_throw
, 0))
1662 cp_error_at ("looser throw specifier for `%#F'", overrider
);
1663 cp_error_at (" overriding `%#F'", basefn
);
1664 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1671 /* Given a class TYPE, and a function decl FNDECL, look for
1672 virtual functions in TYPE's hierarchy which FNDECL overrides.
1673 We do not look in TYPE itself, only its bases.
1675 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1676 find that it overrides anything.
1678 We check that every function which is overridden, is correctly
1682 look_for_overrides (tree type
, tree fndecl
)
1684 tree binfo
= TYPE_BINFO (type
);
1689 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1691 tree basetype
= BINFO_TYPE (base_binfo
);
1693 if (TYPE_POLYMORPHIC_P (basetype
))
1694 found
+= look_for_overrides_r (basetype
, fndecl
);
1699 /* Look in TYPE for virtual functions with the same signature as
1703 look_for_overrides_here (tree type
, tree fndecl
)
1707 /* If there are no methods in TYPE (meaning that only implicitly
1708 declared methods will ever be provided for TYPE), then there are
1709 no virtual functions. */
1710 if (!CLASSTYPE_METHOD_VEC (type
))
1713 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl
))
1714 ix
= CLASSTYPE_DESTRUCTOR_SLOT
;
1716 ix
= lookup_fnfields_1 (type
, DECL_NAME (fndecl
));
1719 tree fns
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), ix
);
1721 for (; fns
; fns
= OVL_NEXT (fns
))
1723 tree fn
= OVL_CURRENT (fns
);
1725 if (!DECL_VIRTUAL_P (fn
))
1726 /* Not a virtual. */;
1727 else if (DECL_CONTEXT (fn
) != type
)
1728 /* Introduced with a using declaration. */;
1729 else if (DECL_STATIC_FUNCTION_P (fndecl
))
1731 tree btypes
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
1732 tree dtypes
= TYPE_ARG_TYPES (TREE_TYPE (fndecl
));
1733 if (compparms (TREE_CHAIN (btypes
), dtypes
))
1736 else if (same_signature_p (fndecl
, fn
))
1743 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1744 TYPE itself and its bases. */
1747 look_for_overrides_r (tree type
, tree fndecl
)
1749 tree fn
= look_for_overrides_here (type
, fndecl
);
1752 if (DECL_STATIC_FUNCTION_P (fndecl
))
1754 /* A static member function cannot match an inherited
1755 virtual member function. */
1756 cp_error_at ("`%#D' cannot be declared", fndecl
);
1757 cp_error_at (" since `%#D' declared in base class", fn
);
1761 /* It's definitely virtual, even if not explicitly set. */
1762 DECL_VIRTUAL_P (fndecl
) = 1;
1763 check_final_overrider (fndecl
, fn
);
1768 /* We failed to find one declared in this class. Look in its bases. */
1769 return look_for_overrides (type
, fndecl
);
1772 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1775 dfs_get_pure_virtuals (tree binfo
, void *data
)
1777 tree type
= (tree
) data
;
1779 /* We're not interested in primary base classes; the derived class
1780 of which they are a primary base will contain the information we
1782 if (!BINFO_PRIMARY_P (binfo
))
1786 for (virtuals
= BINFO_VIRTUALS (binfo
);
1788 virtuals
= TREE_CHAIN (virtuals
))
1789 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals
)))
1790 VEC_safe_push (tree
, CLASSTYPE_PURE_VIRTUALS (type
),
1794 BINFO_MARKED (binfo
) = 1;
1799 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1802 get_pure_virtuals (tree type
)
1804 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1805 is going to be overridden. */
1806 CLASSTYPE_PURE_VIRTUALS (type
) = NULL
;
1807 /* Now, run through all the bases which are not primary bases, and
1808 collect the pure virtual functions. We look at the vtable in
1809 each class to determine what pure virtual functions are present.
1810 (A primary base is not interesting because the derived class of
1811 which it is a primary base will contain vtable entries for the
1812 pure virtuals in the base class. */
1813 dfs_walk (TYPE_BINFO (type
), dfs_get_pure_virtuals
, unmarkedp
, type
);
1814 dfs_walk (TYPE_BINFO (type
), dfs_unmark
, markedp
, type
);
1817 /* DEPTH-FIRST SEARCH ROUTINES. */
1820 markedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1822 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1824 return BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1828 unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1830 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1832 return !BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1835 /* The worker functions for `dfs_walk'. These do not need to
1836 test anything (vis a vis marking) if they are paired with
1837 a predicate function (above). */
1840 dfs_unmark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1842 BINFO_MARKED (binfo
) = 0;
1847 /* Debug info for C++ classes can get very large; try to avoid
1848 emitting it everywhere.
1850 Note that this optimization wins even when the target supports
1851 BINCL (if only slightly), and reduces the amount of work for the
1855 maybe_suppress_debug_info (tree t
)
1857 if (write_symbols
== NO_DEBUG
)
1860 /* We might have set this earlier in cp_finish_decl. */
1861 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 0;
1863 /* If we already know how we're handling this class, handle debug info
1865 if (CLASSTYPE_INTERFACE_KNOWN (t
))
1867 if (CLASSTYPE_INTERFACE_ONLY (t
))
1868 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1869 /* else don't set it. */
1871 /* If the class has a vtable, write out the debug info along with
1873 else if (TYPE_CONTAINS_VPTR_P (t
))
1874 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1876 /* Otherwise, just emit the debug info normally. */
1879 /* Note that we want debugging information for a base class of a class
1880 whose vtable is being emitted. Normally, this would happen because
1881 calling the constructor for a derived class implies calling the
1882 constructors for all bases, which involve initializing the
1883 appropriate vptr with the vtable for the base class; but in the
1884 presence of optimization, this initialization may be optimized
1885 away, so we tell finish_vtable_vardecl that we want the debugging
1886 information anyway. */
1889 dfs_debug_mark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1891 tree t
= BINFO_TYPE (binfo
);
1893 CLASSTYPE_DEBUG_REQUESTED (t
) = 1;
1898 /* Returns BINFO if we haven't already noted that we want debugging
1899 info for this base class. */
1902 dfs_debug_unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1904 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1906 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo
))
1907 ? binfo
: NULL_TREE
);
1910 /* Write out the debugging information for TYPE, whose vtable is being
1911 emitted. Also walk through our bases and note that we want to
1912 write out information for them. This avoids the problem of not
1913 writing any debug info for intermediate basetypes whose
1914 constructors, and thus the references to their vtables, and thus
1915 the vtables themselves, were optimized away. */
1918 note_debug_info_needed (tree type
)
1920 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)))
1922 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)) = 0;
1923 rest_of_type_compilation (type
, toplevel_bindings_p ());
1926 dfs_walk (TYPE_BINFO (type
), dfs_debug_mark
, dfs_debug_unmarkedp
, 0);
1930 print_search_statistics (void)
1932 #ifdef GATHER_STATISTICS
1933 fprintf (stderr
, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
1934 n_fields_searched
, n_calls_lookup_field
, n_calls_lookup_field_1
);
1935 fprintf (stderr
, "%d fnfields searched in %d calls to lookup_fnfields\n",
1936 n_outer_fields_searched
, n_calls_lookup_fnfields
);
1937 fprintf (stderr
, "%d calls to get_base_type\n", n_calls_get_base_type
);
1938 #else /* GATHER_STATISTICS */
1939 fprintf (stderr
, "no search statistics\n");
1940 #endif /* GATHER_STATISTICS */
1944 reinit_search_statistics (void)
1946 #ifdef GATHER_STATISTICS
1947 n_fields_searched
= 0;
1948 n_calls_lookup_field
= 0, n_calls_lookup_field_1
= 0;
1949 n_calls_lookup_fnfields
= 0, n_calls_lookup_fnfields_1
= 0;
1950 n_calls_get_base_type
= 0;
1951 n_outer_fields_searched
= 0;
1952 n_contexts_saved
= 0;
1953 #endif /* GATHER_STATISTICS */
1956 /* Helper for lookup_conversions_r. TO_TYPE is the type converted to
1957 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if
1958 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual
1959 bases have been encountered already in the tree walk. PARENT_CONVS
1960 is the list of lists of conversion functions that could hide CONV
1961 and OTHER_CONVS is the list of lists of conversion functions that
1962 could hide or be hidden by CONV, should virtualness be involved in
1963 the hierarchy. Merely checking the conversion op's name is not
1964 enough because two conversion operators to the same type can have
1965 different names. Return nonzero if we are visible. */
1968 check_hidden_convs (tree binfo
, int virtual_depth
, int virtualness
,
1969 tree to_type
, tree parent_convs
, tree other_convs
)
1973 /* See if we are hidden by a parent conversion. */
1974 for (level
= parent_convs
; level
; level
= TREE_CHAIN (level
))
1975 for (probe
= TREE_VALUE (level
); probe
; probe
= TREE_CHAIN (probe
))
1976 if (same_type_p (to_type
, TREE_TYPE (probe
)))
1979 if (virtual_depth
|| virtualness
)
1981 /* In a virtual hierarchy, we could be hidden, or could hide a
1982 conversion function on the other_convs list. */
1983 for (level
= other_convs
; level
; level
= TREE_CHAIN (level
))
1989 if (!(virtual_depth
|| TREE_STATIC (level
)))
1990 /* Neither is morally virtual, so cannot hide each other. */
1993 if (!TREE_VALUE (level
))
1994 /* They evaporated away already. */
1997 they_hide_us
= (virtual_depth
1998 && original_binfo (binfo
, TREE_PURPOSE (level
)));
1999 we_hide_them
= (!they_hide_us
&& TREE_STATIC (level
)
2000 && original_binfo (TREE_PURPOSE (level
), binfo
));
2002 if (!(we_hide_them
|| they_hide_us
))
2003 /* Neither is within the other, so no hiding can occur. */
2006 for (prev
= &TREE_VALUE (level
), other
= *prev
; other
;)
2008 if (same_type_p (to_type
, TREE_TYPE (other
)))
2011 /* We are hidden. */
2016 /* We hide the other one. */
2017 other
= TREE_CHAIN (other
);
2022 prev
= &TREE_CHAIN (other
);
2030 /* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists
2031 of conversion functions, the first slot will be for the current
2032 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists
2033 of conversion functions from children of the current binfo,
2034 concatenated with conversions from elsewhere in the hierarchy --
2035 that list begins with OTHER_CONVS. Return a single list of lists
2036 containing only conversions from the current binfo and its
2040 split_conversions (tree my_convs
, tree parent_convs
,
2041 tree child_convs
, tree other_convs
)
2046 /* Remove the original other_convs portion from child_convs. */
2047 for (prev
= NULL
, t
= child_convs
;
2048 t
!= other_convs
; prev
= t
, t
= TREE_CHAIN (t
))
2052 TREE_CHAIN (prev
) = NULL_TREE
;
2054 child_convs
= NULL_TREE
;
2056 /* Attach the child convs to any we had at this level. */
2059 my_convs
= parent_convs
;
2060 TREE_CHAIN (my_convs
) = child_convs
;
2063 my_convs
= child_convs
;
2068 /* Worker for lookup_conversions. Lookup conversion functions in
2069 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in
2070 a morally virtual base, and VIRTUALNESS is nonzero, if we've
2071 encountered virtual bases already in the tree walk. PARENT_CONVS &
2072 PARENT_TPL_CONVS are lists of list of conversions within parent
2073 binfos. OTHER_CONVS and OTHER_TPL_CONVS are conversions found
2074 elsewhere in the tree. Return the conversions found within this
2075 portion of the graph in CONVS and TPL_CONVS. Return nonzero is we
2076 encountered virtualness. We keep template and non-template
2077 conversions separate, to avoid unnecessary type comparisons.
2079 The located conversion functions are held in lists of lists. The
2080 TREE_VALUE of the outer list is the list of conversion functions
2081 found in a particular binfo. The TREE_PURPOSE of both the outer
2082 and inner lists is the binfo at which those conversions were
2083 found. TREE_STATIC is set for those lists within of morally
2084 virtual binfos. The TREE_VALUE of the inner list is the conversion
2085 function or overload itself. The TREE_TYPE of each inner list node
2086 is the converted-to type. */
2089 lookup_conversions_r (tree binfo
,
2090 int virtual_depth
, int virtualness
,
2091 tree parent_convs
, tree parent_tpl_convs
,
2092 tree other_convs
, tree other_tpl_convs
,
2093 tree
*convs
, tree
*tpl_convs
)
2095 int my_virtualness
= 0;
2096 tree my_convs
= NULL_TREE
;
2097 tree my_tpl_convs
= NULL_TREE
;
2098 tree child_convs
= NULL_TREE
;
2099 tree child_tpl_convs
= NULL_TREE
;
2102 VEC(tree
) *method_vec
= CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo
));
2105 /* If we have no conversion operators, then don't look. */
2106 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo
)))
2108 *convs
= *tpl_convs
= NULL_TREE
;
2113 if (BINFO_VIRTUAL_P (binfo
))
2116 /* First, locate the unhidden ones at this level. */
2117 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
2118 VEC_iterate (tree
, method_vec
, i
, conv
);
2121 tree cur
= OVL_CURRENT (conv
);
2123 if (!DECL_CONV_FN_P (cur
))
2126 if (TREE_CODE (cur
) == TEMPLATE_DECL
)
2128 /* Only template conversions can be overloaded, and we must
2129 flatten them out and check each one individually. */
2132 for (tpls
= conv
; tpls
; tpls
= OVL_NEXT (tpls
))
2134 tree tpl
= OVL_CURRENT (tpls
);
2135 tree type
= DECL_CONV_FN_TYPE (tpl
);
2137 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2138 type
, parent_tpl_convs
, other_tpl_convs
))
2140 my_tpl_convs
= tree_cons (binfo
, tpl
, my_tpl_convs
);
2141 TREE_TYPE (my_tpl_convs
) = type
;
2144 TREE_STATIC (my_tpl_convs
) = 1;
2152 tree name
= DECL_NAME (cur
);
2154 if (!IDENTIFIER_MARKED (name
))
2156 tree type
= DECL_CONV_FN_TYPE (cur
);
2158 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2159 type
, parent_convs
, other_convs
))
2161 my_convs
= tree_cons (binfo
, conv
, my_convs
);
2162 TREE_TYPE (my_convs
) = type
;
2165 TREE_STATIC (my_convs
) = 1;
2168 IDENTIFIER_MARKED (name
) = 1;
2176 parent_convs
= tree_cons (binfo
, my_convs
, parent_convs
);
2178 TREE_STATIC (parent_convs
) = 1;
2183 parent_tpl_convs
= tree_cons (binfo
, my_tpl_convs
, parent_tpl_convs
);
2185 TREE_STATIC (parent_convs
) = 1;
2188 child_convs
= other_convs
;
2189 child_tpl_convs
= other_tpl_convs
;
2191 /* Now iterate over each base, looking for more conversions. */
2192 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
2194 tree base_convs
, base_tpl_convs
;
2195 unsigned base_virtualness
;
2197 base_virtualness
= lookup_conversions_r (base_binfo
,
2198 virtual_depth
, virtualness
,
2199 parent_convs
, parent_tpl_convs
,
2200 child_convs
, child_tpl_convs
,
2201 &base_convs
, &base_tpl_convs
);
2202 if (base_virtualness
)
2203 my_virtualness
= virtualness
= 1;
2204 child_convs
= chainon (base_convs
, child_convs
);
2205 child_tpl_convs
= chainon (base_tpl_convs
, child_tpl_convs
);
2208 /* Unmark the conversions found at this level */
2209 for (conv
= my_convs
; conv
; conv
= TREE_CHAIN (conv
))
2210 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (conv
)))) = 0;
2212 *convs
= split_conversions (my_convs
, parent_convs
,
2213 child_convs
, other_convs
);
2214 *tpl_convs
= split_conversions (my_tpl_convs
, parent_tpl_convs
,
2215 child_tpl_convs
, other_tpl_convs
);
2217 return my_virtualness
;
2220 /* Return a TREE_LIST containing all the non-hidden user-defined
2221 conversion functions for TYPE (and its base-classes). The
2222 TREE_VALUE of each node is the FUNCTION_DECL of the conversion
2223 function. The TREE_PURPOSE is the BINFO from which the conversion
2224 functions in this node were selected. This function is effectively
2225 performing a set of member lookups as lookup_fnfield does, but
2226 using the type being converted to as the unique key, rather than the
2230 lookup_conversions (tree type
)
2232 tree convs
, tpl_convs
;
2233 tree list
= NULL_TREE
;
2235 complete_type (type
);
2236 if (!TYPE_BINFO (type
))
2239 lookup_conversions_r (TYPE_BINFO (type
), 0, 0,
2240 NULL_TREE
, NULL_TREE
, NULL_TREE
, NULL_TREE
,
2241 &convs
, &tpl_convs
);
2243 /* Flatten the list-of-lists */
2244 for (; convs
; convs
= TREE_CHAIN (convs
))
2248 for (probe
= TREE_VALUE (convs
); probe
; probe
= next
)
2250 next
= TREE_CHAIN (probe
);
2252 TREE_CHAIN (probe
) = list
;
2257 for (; tpl_convs
; tpl_convs
= TREE_CHAIN (tpl_convs
))
2261 for (probe
= TREE_VALUE (tpl_convs
); probe
; probe
= next
)
2263 next
= TREE_CHAIN (probe
);
2265 TREE_CHAIN (probe
) = list
;
2273 /* Returns the binfo of the first direct or indirect virtual base derived
2274 from BINFO, or NULL if binfo is not via virtual. */
2277 binfo_from_vbase (tree binfo
)
2279 for (; binfo
; binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2281 if (BINFO_VIRTUAL_P (binfo
))
2287 /* Returns the binfo of the first direct or indirect virtual base derived
2288 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2292 binfo_via_virtual (tree binfo
, tree limit
)
2294 for (; binfo
&& (!limit
|| !same_type_p (BINFO_TYPE (binfo
), limit
));
2295 binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2297 if (BINFO_VIRTUAL_P (binfo
))
2303 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2304 Find the equivalent binfo within whatever graph HERE is located.
2305 This is the inverse of original_binfo. */
2308 copied_binfo (tree binfo
, tree here
)
2310 tree result
= NULL_TREE
;
2312 if (BINFO_VIRTUAL_P (binfo
))
2316 for (t
= here
; BINFO_INHERITANCE_CHAIN (t
);
2317 t
= BINFO_INHERITANCE_CHAIN (t
))
2320 result
= binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (t
));
2322 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2328 cbinfo
= copied_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2329 for (ix
= 0; BINFO_BASE_ITERATE (cbinfo
, ix
, base_binfo
); ix
++)
2330 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2332 result
= base_binfo
;
2338 gcc_assert (BINFO_TYPE (here
) == BINFO_TYPE (binfo
));
2342 gcc_assert (result
);
2347 binfo_for_vbase (tree base
, tree t
)
2353 for (vbases
= CLASSTYPE_VBASECLASSES (t
), ix
= 0;
2354 VEC_iterate (tree
, vbases
, ix
, binfo
); ix
++)
2355 if (BINFO_TYPE (binfo
) == base
)
2360 /* BINFO is some base binfo of HERE, within some other
2361 hierarchy. Return the equivalent binfo, but in the hierarchy
2362 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2363 is not a base binfo of HERE, returns NULL_TREE. */
2366 original_binfo (tree binfo
, tree here
)
2370 if (BINFO_TYPE (binfo
) == BINFO_TYPE (here
))
2372 else if (BINFO_VIRTUAL_P (binfo
))
2373 result
= (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here
))
2374 ? binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (here
))
2376 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2380 base_binfos
= original_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2386 for (ix
= 0; (base_binfo
= BINFO_BASE_BINFO (base_binfos
, ix
)); ix
++)
2387 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2389 result
= base_binfo
;