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 tree
lookup_field_r (tree
, void *);
60 static tree
dfs_accessible_queue_p (tree
, int, void *);
61 static tree
dfs_accessible_p (tree
, void *);
62 static tree
dfs_access_in_type (tree
, void *);
63 static access_kind
access_in_type (tree
, tree
);
64 static int protected_accessible_p (tree
, tree
, tree
);
65 static int friend_accessible_p (tree
, tree
, tree
);
66 static int template_self_reference_p (tree
, tree
);
67 static tree
dfs_get_pure_virtuals (tree
, void *);
70 /* Variables for gathering statistics. */
71 #ifdef GATHER_STATISTICS
72 static int n_fields_searched
;
73 static int n_calls_lookup_field
, n_calls_lookup_field_1
;
74 static int n_calls_lookup_fnfields
, n_calls_lookup_fnfields_1
;
75 static int n_calls_get_base_type
;
76 static int n_outer_fields_searched
;
77 static int n_contexts_saved
;
78 #endif /* GATHER_STATISTICS */
81 /* Worker for lookup_base. BINFO is the binfo we are searching at,
82 BASE is the RECORD_TYPE we are searching for. ACCESS is the
83 required access checks. IS_VIRTUAL indicates if BINFO is morally
86 If BINFO is of the required type, then *BINFO_PTR is examined to
87 compare with any other instance of BASE we might have already
88 discovered. *BINFO_PTR is initialized and a base_kind return value
89 indicates what kind of base was located.
91 Otherwise BINFO's bases are searched. */
94 lookup_base_r (tree binfo
, tree base
, base_access access
,
95 bool is_virtual
, /* inside a virtual part */
100 base_kind found
= bk_not_base
;
102 if (same_type_p (BINFO_TYPE (binfo
), base
))
104 /* We have found a base. Check against what we have found
106 found
= bk_same_type
;
108 found
= bk_via_virtual
;
112 else if (binfo
!= *binfo_ptr
)
114 if (access
!= ba_any
)
116 else if (!is_virtual
)
117 /* Prefer a non-virtual base. */
125 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
129 bk
= lookup_base_r (base_binfo
, base
,
131 is_virtual
|| BINFO_VIRTUAL_P (base_binfo
),
137 if (access
!= ba_any
)
146 gcc_assert (found
== bk_not_base
);
151 if (found
!= bk_ambig
)
165 /* Returns true if type BASE is accessible in T. (BASE is known to be
166 a (possibly non-proper) base class of T.) */
169 accessible_base_p (tree t
, tree base
)
173 /* [class.access.base]
175 A base class is said to be accessible if an invented public
176 member of the base class is accessible.
178 If BASE is a non-proper base, this condition is trivially
180 if (same_type_p (t
, base
))
182 /* Rather than inventing a public member, we use the implicit
183 public typedef created in the scope of every class. */
184 decl
= TYPE_FIELDS (base
);
185 while (!DECL_SELF_REFERENCE_P (decl
))
186 decl
= TREE_CHAIN (decl
);
187 while (ANON_AGGR_TYPE_P (t
))
188 t
= TYPE_CONTEXT (t
);
189 return accessible_p (t
, decl
);
192 /* Lookup BASE in the hierarchy dominated by T. Do access checking as
193 ACCESS specifies. Return the binfo we discover. If KIND_PTR is
194 non-NULL, fill with information about what kind of base we
197 If the base is inaccessible, or ambiguous, and the ba_quiet bit is
198 not set in ACCESS, then an error is issued and error_mark_node is
199 returned. If the ba_quiet bit is set, then no error is issued and
200 NULL_TREE is returned. */
203 lookup_base (tree t
, tree base
, base_access access
, base_kind
*kind_ptr
)
205 tree binfo
= NULL_TREE
; /* The binfo we've found so far. */
206 tree t_binfo
= NULL_TREE
;
209 if (t
== error_mark_node
|| base
== error_mark_node
)
212 *kind_ptr
= bk_not_base
;
213 return error_mark_node
;
215 gcc_assert (TYPE_P (base
));
224 t
= complete_type (TYPE_MAIN_VARIANT (t
));
225 t_binfo
= TYPE_BINFO (t
);
228 base
= complete_type (TYPE_MAIN_VARIANT (base
));
231 bk
= lookup_base_r (t_binfo
, base
, access
, 0, &binfo
);
235 /* Check that the base is unambiguous and accessible. */
236 if (access
!= ba_any
)
244 if (!(access
& ba_quiet
))
246 error ("`%T' is an ambiguous base of `%T'", base
, t
);
247 binfo
= error_mark_node
;
252 if ((access
& ~ba_quiet
) != ba_ignore
253 /* If BASE is incomplete, then BASE and TYPE are probably
254 the same, in which case BASE is accessible. If they
255 are not the same, then TYPE is invalid. In that case,
256 there's no need to issue another error here, and
257 there's no implicit typedef to use in the code that
258 follows, so we skip the check. */
259 && COMPLETE_TYPE_P (base
)
260 && !accessible_base_p (t
, base
))
262 if (!(access
& ba_quiet
))
264 error ("`%T' is an inaccessible base of `%T'", base
, t
);
265 binfo
= error_mark_node
;
269 bk
= bk_inaccessible
;
280 /* Worker function for get_dynamic_cast_base_type. */
283 dynamic_cast_base_recurse (tree subtype
, tree binfo
, bool is_via_virtual
,
286 VEC (tree
) *accesses
;
291 if (BINFO_TYPE (binfo
) == subtype
)
297 *offset_ptr
= BINFO_OFFSET (binfo
);
302 accesses
= BINFO_BASE_ACCESSES (binfo
);
303 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
305 tree base_access
= VEC_index (tree
, accesses
, i
);
308 if (base_access
!= access_public_node
)
310 rval
= dynamic_cast_base_recurse
311 (subtype
, base_binfo
,
312 is_via_virtual
|| BINFO_VIRTUAL_P (base_binfo
), offset_ptr
);
316 worst
= worst
>= 0 ? -3 : worst
;
319 else if (rval
== -3 && worst
!= -1)
325 /* The dynamic cast runtime needs a hint about how the static SUBTYPE type
326 started from is related to the required TARGET type, in order to optimize
327 the inheritance graph search. This information is independent of the
328 current context, and ignores private paths, hence get_base_distance is
329 inappropriate. Return a TREE specifying the base offset, BOFF.
330 BOFF >= 0, there is only one public non-virtual SUBTYPE base at offset BOFF,
331 and there are no public virtual SUBTYPE bases.
332 BOFF == -1, SUBTYPE occurs as multiple public virtual or non-virtual bases.
333 BOFF == -2, SUBTYPE is not a public base.
334 BOFF == -3, SUBTYPE occurs as multiple public non-virtual bases. */
337 get_dynamic_cast_base_type (tree subtype
, tree target
)
339 tree offset
= NULL_TREE
;
340 int boff
= dynamic_cast_base_recurse (subtype
, TYPE_BINFO (target
),
345 offset
= ssize_int (boff
);
349 /* Search for a member with name NAME in a multiple inheritance
350 lattice specified by TYPE. If it does not exist, return NULL_TREE.
351 If the member is ambiguously referenced, return `error_mark_node'.
352 Otherwise, return a DECL with the indicated name. If WANT_TYPE is
353 true, type declarations are preferred. */
355 /* Do a 1-level search for NAME as a member of TYPE. The caller must
356 figure out whether it can access this field. (Since it is only one
357 level, this is reasonable.) */
360 lookup_field_1 (tree type
, tree name
, bool want_type
)
364 if (TREE_CODE (type
) == TEMPLATE_TYPE_PARM
365 || TREE_CODE (type
) == BOUND_TEMPLATE_TEMPLATE_PARM
366 || TREE_CODE (type
) == TYPENAME_TYPE
)
367 /* The TYPE_FIELDS of a TEMPLATE_TYPE_PARM and
368 BOUND_TEMPLATE_TEMPLATE_PARM are not fields at all;
369 instead TYPE_FIELDS is the TEMPLATE_PARM_INDEX. (Miraculously,
370 the code often worked even when we treated the index as a list
372 The TYPE_FIELDS of TYPENAME_TYPE is its TYPENAME_TYPE_FULLNAME. */
376 && DECL_LANG_SPECIFIC (TYPE_NAME (type
))
377 && DECL_SORTED_FIELDS (TYPE_NAME (type
)))
379 tree
*fields
= &DECL_SORTED_FIELDS (TYPE_NAME (type
))->elts
[0];
380 int lo
= 0, hi
= DECL_SORTED_FIELDS (TYPE_NAME (type
))->len
;
387 #ifdef GATHER_STATISTICS
389 #endif /* GATHER_STATISTICS */
391 if (DECL_NAME (fields
[i
]) > name
)
393 else if (DECL_NAME (fields
[i
]) < name
)
399 /* We might have a nested class and a field with the
400 same name; we sorted them appropriately via
401 field_decl_cmp, so just look for the first or last
402 field with this name. */
407 while (i
>= lo
&& DECL_NAME (fields
[i
]) == name
);
408 if (TREE_CODE (field
) != TYPE_DECL
409 && !DECL_CLASS_TEMPLATE_P (field
))
416 while (i
< hi
&& DECL_NAME (fields
[i
]) == name
);
424 field
= TYPE_FIELDS (type
);
426 #ifdef GATHER_STATISTICS
427 n_calls_lookup_field_1
++;
428 #endif /* GATHER_STATISTICS */
429 for (field
= TYPE_FIELDS (type
); field
; field
= TREE_CHAIN (field
))
431 #ifdef GATHER_STATISTICS
433 #endif /* GATHER_STATISTICS */
434 gcc_assert (DECL_P (field
));
435 if (DECL_NAME (field
) == NULL_TREE
436 && ANON_AGGR_TYPE_P (TREE_TYPE (field
)))
438 tree temp
= lookup_field_1 (TREE_TYPE (field
), name
, want_type
);
442 if (TREE_CODE (field
) == USING_DECL
)
444 /* We generally treat class-scope using-declarations as
445 ARM-style access specifications, because support for the
446 ISO semantics has not been implemented. So, in general,
447 there's no reason to return a USING_DECL, and the rest of
448 the compiler cannot handle that. Once the class is
449 defined, USING_DECLs are purged from TYPE_FIELDS; see
450 handle_using_decl. However, we make special efforts to
451 make using-declarations in template classes work
453 if (CLASSTYPE_TEMPLATE_INFO (type
)
454 && !CLASSTYPE_USE_TEMPLATE (type
)
455 && !TREE_TYPE (field
))
461 if (DECL_NAME (field
) == name
463 || TREE_CODE (field
) == TYPE_DECL
464 || DECL_CLASS_TEMPLATE_P (field
)))
468 if (name
== vptr_identifier
)
470 /* Give the user what s/he thinks s/he wants. */
471 if (TYPE_POLYMORPHIC_P (type
))
472 return TYPE_VFIELD (type
);
477 /* There are a number of cases we need to be aware of here:
478 current_class_type current_function_decl
485 Those last two make life interesting. If we're in a function which is
486 itself inside a class, we need decls to go into the fn's decls (our
487 second case below). But if we're in a class and the class itself is
488 inside a function, we need decls to go into the decls for the class. To
489 achieve this last goal, we must see if, when both current_class_ptr and
490 current_function_decl are set, the class was declared inside that
491 function. If so, we know to put the decls into the class's scope. */
496 if (current_function_decl
== NULL_TREE
)
497 return current_class_type
;
498 if (current_class_type
== NULL_TREE
)
499 return current_function_decl
;
500 if ((DECL_FUNCTION_MEMBER_P (current_function_decl
)
501 && same_type_p (DECL_CONTEXT (current_function_decl
),
503 || (DECL_FRIEND_CONTEXT (current_function_decl
)
504 && same_type_p (DECL_FRIEND_CONTEXT (current_function_decl
),
505 current_class_type
)))
506 return current_function_decl
;
508 return current_class_type
;
511 /* Returns nonzero if we are currently in a function scope. Note
512 that this function returns zero if we are within a local class, but
513 not within a member function body of the local class. */
516 at_function_scope_p (void)
518 tree cs
= current_scope ();
519 return cs
&& TREE_CODE (cs
) == FUNCTION_DECL
;
522 /* Returns true if the innermost active scope is a class scope. */
525 at_class_scope_p (void)
527 tree cs
= current_scope ();
528 return cs
&& TYPE_P (cs
);
531 /* Returns true if the innermost active scope is a namespace scope. */
534 at_namespace_scope_p (void)
536 /* We are in a namespace scope if we are not it a class scope or a
538 return !current_scope();
541 /* Return the scope of DECL, as appropriate when doing name-lookup. */
544 context_for_name_lookup (tree decl
)
548 For the purposes of name lookup, after the anonymous union
549 definition, the members of the anonymous union are considered to
550 have been defined in the scope in which the anonymous union is
552 tree context
= DECL_CONTEXT (decl
);
554 while (context
&& TYPE_P (context
) && ANON_AGGR_TYPE_P (context
))
555 context
= TYPE_CONTEXT (context
);
557 context
= global_namespace
;
562 /* The accessibility routines use BINFO_ACCESS for scratch space
563 during the computation of the accessibility of some declaration. */
565 #define BINFO_ACCESS(NODE) \
566 ((access_kind) ((TREE_PUBLIC (NODE) << 1) | TREE_PRIVATE (NODE)))
568 /* Set the access associated with NODE to ACCESS. */
570 #define SET_BINFO_ACCESS(NODE, ACCESS) \
571 ((TREE_PUBLIC (NODE) = ((ACCESS) & 2) != 0), \
572 (TREE_PRIVATE (NODE) = ((ACCESS) & 1) != 0))
574 /* Called from access_in_type via dfs_walk. Calculate the access to
575 DATA (which is really a DECL) in BINFO. */
578 dfs_access_in_type (tree binfo
, void *data
)
580 tree decl
= (tree
) data
;
581 tree type
= BINFO_TYPE (binfo
);
582 access_kind access
= ak_none
;
584 if (context_for_name_lookup (decl
) == type
)
586 /* If we have descended to the scope of DECL, just note the
587 appropriate access. */
588 if (TREE_PRIVATE (decl
))
590 else if (TREE_PROTECTED (decl
))
591 access
= ak_protected
;
597 /* First, check for an access-declaration that gives us more
598 access to the DECL. The CONST_DECL for an enumeration
599 constant will not have DECL_LANG_SPECIFIC, and thus no
601 if (DECL_LANG_SPECIFIC (decl
) && !DECL_DISCRIMINATOR_P (decl
))
603 tree decl_access
= purpose_member (type
, DECL_ACCESS (decl
));
607 decl_access
= TREE_VALUE (decl_access
);
609 if (decl_access
== access_public_node
)
611 else if (decl_access
== access_protected_node
)
612 access
= ak_protected
;
613 else if (decl_access
== access_private_node
)
624 VEC (tree
) *accesses
;
626 /* Otherwise, scan our baseclasses, and pick the most favorable
628 accesses
= BINFO_BASE_ACCESSES (binfo
);
629 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
631 tree base_access
= VEC_index (tree
, accesses
, i
);
632 access_kind base_access_now
= BINFO_ACCESS (base_binfo
);
634 if (base_access_now
== ak_none
|| base_access_now
== ak_private
)
635 /* If it was not accessible in the base, or only
636 accessible as a private member, we can't access it
638 base_access_now
= ak_none
;
639 else if (base_access
== access_protected_node
)
640 /* Public and protected members in the base become
642 base_access_now
= ak_protected
;
643 else if (base_access
== access_private_node
)
644 /* Public and protected members in the base become
646 base_access_now
= ak_private
;
648 /* See if the new access, via this base, gives more
649 access than our previous best access. */
650 if (base_access_now
!= ak_none
651 && (access
== ak_none
|| base_access_now
< access
))
653 access
= base_access_now
;
655 /* If the new access is public, we can't do better. */
656 if (access
== ak_public
)
663 /* Note the access to DECL in TYPE. */
664 SET_BINFO_ACCESS (binfo
, access
);
666 /* Mark TYPE as visited so that if we reach it again we do not
667 duplicate our efforts here. */
668 BINFO_MARKED (binfo
) = 1;
673 /* Return the access to DECL in TYPE. */
676 access_in_type (tree type
, tree decl
)
678 tree binfo
= TYPE_BINFO (type
);
680 /* We must take into account
684 If a name can be reached by several paths through a multiple
685 inheritance graph, the access is that of the path that gives
688 The algorithm we use is to make a post-order depth-first traversal
689 of the base-class hierarchy. As we come up the tree, we annotate
690 each node with the most lenient access. */
691 dfs_walk_real (binfo
, 0, dfs_access_in_type
, unmarkedp
, decl
);
692 dfs_walk (binfo
, dfs_unmark
, markedp
, 0);
694 return BINFO_ACCESS (binfo
);
697 /* Called from accessible_p via dfs_walk. */
700 dfs_accessible_queue_p (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
702 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
704 if (BINFO_MARKED (binfo
))
707 /* If this class is inherited via private or protected inheritance,
708 then we can't see it, unless we are a friend of the derived class. */
709 if (BINFO_BASE_ACCESS (derived
, ix
) != access_public_node
710 && !is_friend (BINFO_TYPE (derived
), current_scope ()))
716 /* Called from accessible_p via dfs_walk. */
719 dfs_accessible_p (tree binfo
, void *data ATTRIBUTE_UNUSED
)
723 BINFO_MARKED (binfo
) = 1;
724 access
= BINFO_ACCESS (binfo
);
725 if (access
!= ak_none
726 && is_friend (BINFO_TYPE (binfo
), current_scope ()))
732 /* Returns nonzero if it is OK to access DECL through an object
733 indicated by BINFO in the context of DERIVED. */
736 protected_accessible_p (tree decl
, tree derived
, tree binfo
)
740 /* We're checking this clause from [class.access.base]
742 m as a member of N is protected, and the reference occurs in a
743 member or friend of class N, or in a member or friend of a
744 class P derived from N, where m as a member of P is private or
747 Here DERIVED is a possible P and DECL is m. accessible_p will
748 iterate over various values of N, but the access to m in DERIVED
751 Note that I believe that the passage above is wrong, and should read
752 "...is private or protected or public"; otherwise you get bizarre results
753 whereby a public using-decl can prevent you from accessing a protected
754 member of a base. (jason 2000/02/28) */
756 /* If DERIVED isn't derived from m's class, then it can't be a P. */
757 if (!DERIVED_FROM_P (context_for_name_lookup (decl
), derived
))
760 access
= access_in_type (derived
, decl
);
762 /* If m is inaccessible in DERIVED, then it's not a P. */
763 if (access
== ak_none
)
768 When a friend or a member function of a derived class references
769 a protected nonstatic member of a base class, an access check
770 applies in addition to those described earlier in clause
771 _class.access_) Except when forming a pointer to member
772 (_expr.unary.op_), the access must be through a pointer to,
773 reference to, or object of the derived class itself (or any class
774 derived from that class) (_expr.ref_). If the access is to form
775 a pointer to member, the nested-name-specifier shall name the
776 derived class (or any class derived from that class). */
777 if (DECL_NONSTATIC_MEMBER_P (decl
))
779 /* We can tell through what the reference is occurring by
780 chasing BINFO up to the root. */
782 while (BINFO_INHERITANCE_CHAIN (t
))
783 t
= BINFO_INHERITANCE_CHAIN (t
);
785 if (!DERIVED_FROM_P (derived
, BINFO_TYPE (t
)))
792 /* Returns nonzero if SCOPE is a friend of a type which would be able
793 to access DECL through the object indicated by BINFO. */
796 friend_accessible_p (tree scope
, tree decl
, tree binfo
)
798 tree befriending_classes
;
804 if (TREE_CODE (scope
) == FUNCTION_DECL
805 || DECL_FUNCTION_TEMPLATE_P (scope
))
806 befriending_classes
= DECL_BEFRIENDING_CLASSES (scope
);
807 else if (TYPE_P (scope
))
808 befriending_classes
= CLASSTYPE_BEFRIENDING_CLASSES (scope
);
812 for (t
= befriending_classes
; t
; t
= TREE_CHAIN (t
))
813 if (protected_accessible_p (decl
, TREE_VALUE (t
), binfo
))
816 /* Nested classes are implicitly friends of their enclosing types, as
817 per core issue 45 (this is a change from the standard). */
819 for (t
= TYPE_CONTEXT (scope
); t
&& TYPE_P (t
); t
= TYPE_CONTEXT (t
))
820 if (protected_accessible_p (decl
, t
, binfo
))
823 if (TREE_CODE (scope
) == FUNCTION_DECL
824 || DECL_FUNCTION_TEMPLATE_P (scope
))
826 /* Perhaps this SCOPE is a member of a class which is a
828 if (DECL_CLASS_SCOPE_P (decl
)
829 && friend_accessible_p (DECL_CONTEXT (scope
), decl
, binfo
))
832 /* Or an instantiation of something which is a friend. */
833 if (DECL_TEMPLATE_INFO (scope
))
836 /* Increment processing_template_decl to make sure that
837 dependent_type_p works correctly. */
838 ++processing_template_decl
;
839 ret
= friend_accessible_p (DECL_TI_TEMPLATE (scope
), decl
, binfo
);
840 --processing_template_decl
;
844 else if (CLASSTYPE_TEMPLATE_INFO (scope
))
847 /* Increment processing_template_decl to make sure that
848 dependent_type_p works correctly. */
849 ++processing_template_decl
;
850 ret
= friend_accessible_p (CLASSTYPE_TI_TEMPLATE (scope
), decl
, binfo
);
851 --processing_template_decl
;
858 /* DECL is a declaration from a base class of TYPE, which was the
859 class used to name DECL. Return nonzero if, in the current
860 context, DECL is accessible. If TYPE is actually a BINFO node,
861 then we can tell in what context the access is occurring by looking
862 at the most derived class along the path indicated by BINFO. */
865 accessible_p (tree type
, tree decl
)
872 /* Nonzero if it's OK to access DECL if it has protected
873 accessibility in TYPE. */
874 int protected_ok
= 0;
876 /* If this declaration is in a block or namespace scope, there's no
878 if (!TYPE_P (context_for_name_lookup (decl
)))
881 /* There is no need to perform access checks inside a thunk. */
882 scope
= current_scope ();
883 if (scope
&& DECL_THUNK_P (scope
))
886 /* In a template declaration, we cannot be sure whether the
887 particular specialization that is instantiated will be a friend
888 or not. Therefore, all access checks are deferred until
890 if (processing_template_decl
)
896 type
= BINFO_TYPE (type
);
899 binfo
= TYPE_BINFO (type
);
901 /* [class.access.base]
903 A member m is accessible when named in class N if
905 --m as a member of N is public, or
907 --m as a member of N is private, and the reference occurs in a
908 member or friend of class N, or
910 --m as a member of N is protected, and the reference occurs in a
911 member or friend of class N, or in a member or friend of a
912 class P derived from N, where m as a member of P is private or
915 --there exists a base class B of N that is accessible at the point
916 of reference, and m is accessible when named in class B.
918 We walk the base class hierarchy, checking these conditions. */
920 /* Figure out where the reference is occurring. Check to see if
921 DECL is private or protected in this scope, since that will
922 determine whether protected access is allowed. */
923 if (current_class_type
)
924 protected_ok
= protected_accessible_p (decl
, current_class_type
, binfo
);
926 /* Now, loop through the classes of which we are a friend. */
928 protected_ok
= friend_accessible_p (scope
, decl
, binfo
);
930 /* Standardize the binfo that access_in_type will use. We don't
931 need to know what path was chosen from this point onwards. */
932 binfo
= TYPE_BINFO (type
);
934 /* Compute the accessibility of DECL in the class hierarchy
935 dominated by type. */
936 access
= access_in_type (type
, decl
);
937 if (access
== ak_public
938 || (access
== ak_protected
&& protected_ok
))
942 /* Walk the hierarchy again, looking for a base class that allows
944 t
= dfs_walk (binfo
, dfs_accessible_p
, dfs_accessible_queue_p
, 0);
945 /* Clear any mark bits. Note that we have to walk the whole tree
946 here, since we have aborted the previous walk from some point
948 dfs_walk (binfo
, dfs_unmark
, 0, 0);
950 return t
!= NULL_TREE
;
954 struct lookup_field_info
{
955 /* The type in which we're looking. */
957 /* The name of the field for which we're looking. */
959 /* If non-NULL, the current result of the lookup. */
961 /* The path to RVAL. */
963 /* If non-NULL, the lookup was ambiguous, and this is a list of the
966 /* If nonzero, we are looking for types, not data members. */
968 /* If something went wrong, a message indicating what. */
972 /* Returns nonzero if BINFO is not hidden by the value found by the
973 lookup so far. If BINFO is hidden, then there's no need to look in
974 it. DATA is really a struct lookup_field_info. Called from
975 lookup_field via breadth_first_search. */
978 lookup_field_queue_p (tree derived
, int ix
, void *data
)
980 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
981 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
983 /* Don't look for constructors or destructors in base classes. */
984 if (IDENTIFIER_CTOR_OR_DTOR_P (lfi
->name
))
987 /* If this base class is hidden by the best-known value so far, we
988 don't need to look. */
989 if (lfi
->rval_binfo
&& derived
== lfi
->rval_binfo
)
992 /* If this is a dependent base, don't look in it. */
993 if (BINFO_DEPENDENT_BASE_P (binfo
))
999 /* Within the scope of a template class, you can refer to the to the
1000 current specialization with the name of the template itself. For
1003 template <typename T> struct S { S* sp; }
1005 Returns nonzero if DECL is such a declaration in a class TYPE. */
1008 template_self_reference_p (tree type
, tree decl
)
1010 return (CLASSTYPE_USE_TEMPLATE (type
)
1011 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type
))
1012 && TREE_CODE (decl
) == TYPE_DECL
1013 && DECL_ARTIFICIAL (decl
)
1014 && DECL_NAME (decl
) == constructor_name (type
));
1017 /* Nonzero for a class member means that it is shared between all objects
1020 [class.member.lookup]:If the resulting set of declarations are not all
1021 from sub-objects of the same type, or the set has a nonstatic member
1022 and includes members from distinct sub-objects, there is an ambiguity
1023 and the program is ill-formed.
1025 This function checks that T contains no nonstatic members. */
1028 shared_member_p (tree t
)
1030 if (TREE_CODE (t
) == VAR_DECL
|| TREE_CODE (t
) == TYPE_DECL \
1031 || TREE_CODE (t
) == CONST_DECL
)
1033 if (is_overloaded_fn (t
))
1035 for (; t
; t
= OVL_NEXT (t
))
1037 tree fn
= OVL_CURRENT (t
);
1038 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn
))
1046 /* Routine to see if the sub-object denoted by the binfo PARENT can be
1047 found as a base class and sub-object of the object denoted by
1051 is_subobject_of_p (tree parent
, tree binfo
)
1055 for (probe
= parent
; probe
; probe
= BINFO_INHERITANCE_CHAIN (probe
))
1059 if (BINFO_VIRTUAL_P (probe
))
1060 return (binfo_for_vbase (BINFO_TYPE (probe
), BINFO_TYPE (binfo
))
1066 /* DATA is really a struct lookup_field_info. Look for a field with
1067 the name indicated there in BINFO. If this function returns a
1068 non-NULL value it is the result of the lookup. Called from
1069 lookup_field via breadth_first_search. */
1072 lookup_field_r (tree binfo
, void *data
)
1074 struct lookup_field_info
*lfi
= (struct lookup_field_info
*) data
;
1075 tree type
= BINFO_TYPE (binfo
);
1076 tree nval
= NULL_TREE
;
1078 /* First, look for a function. There can't be a function and a data
1079 member with the same name, and if there's a function and a type
1080 with the same name, the type is hidden by the function. */
1081 if (!lfi
->want_type
)
1083 int idx
= lookup_fnfields_1 (type
, lfi
->name
);
1085 nval
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), idx
);
1089 /* Look for a data member or type. */
1090 nval
= lookup_field_1 (type
, lfi
->name
, lfi
->want_type
);
1092 /* If there is no declaration with the indicated name in this type,
1093 then there's nothing to do. */
1097 /* If we're looking up a type (as with an elaborated type specifier)
1098 we ignore all non-types we find. */
1099 if (lfi
->want_type
&& TREE_CODE (nval
) != TYPE_DECL
1100 && !DECL_CLASS_TEMPLATE_P (nval
))
1102 if (lfi
->name
== TYPE_IDENTIFIER (type
))
1104 /* If the aggregate has no user defined constructors, we allow
1105 it to have fields with the same name as the enclosing type.
1106 If we are looking for that name, find the corresponding
1108 for (nval
= TREE_CHAIN (nval
); nval
; nval
= TREE_CHAIN (nval
))
1109 if (DECL_NAME (nval
) == lfi
->name
1110 && TREE_CODE (nval
) == TYPE_DECL
)
1115 if (!nval
&& CLASSTYPE_NESTED_UTDS (type
) != NULL
)
1117 binding_entry e
= binding_table_find (CLASSTYPE_NESTED_UTDS (type
),
1120 nval
= TYPE_MAIN_DECL (e
->type
);
1126 /* You must name a template base class with a template-id. */
1127 if (!same_type_p (type
, lfi
->type
)
1128 && template_self_reference_p (type
, nval
))
1131 /* If the lookup already found a match, and the new value doesn't
1132 hide the old one, we might have an ambiguity. */
1134 && !is_subobject_of_p (lfi
->rval_binfo
, binfo
))
1137 if (nval
== lfi
->rval
&& shared_member_p (nval
))
1138 /* The two things are really the same. */
1140 else if (is_subobject_of_p (binfo
, lfi
->rval_binfo
))
1141 /* The previous value hides the new one. */
1145 /* We have a real ambiguity. We keep a chain of all the
1147 if (!lfi
->ambiguous
&& lfi
->rval
)
1149 /* This is the first time we noticed an ambiguity. Add
1150 what we previously thought was a reasonable candidate
1152 lfi
->ambiguous
= tree_cons (NULL_TREE
, lfi
->rval
, NULL_TREE
);
1153 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1156 /* Add the new value. */
1157 lfi
->ambiguous
= tree_cons (NULL_TREE
, nval
, lfi
->ambiguous
);
1158 TREE_TYPE (lfi
->ambiguous
) = error_mark_node
;
1159 lfi
->errstr
= "request for member `%D' is ambiguous";
1165 lfi
->rval_binfo
= binfo
;
1171 /* Return a "baselink" with BASELINK_BINFO, BASELINK_ACCESS_BINFO,
1172 BASELINK_FUNCTIONS, and BASELINK_OPTYPE set to BINFO, ACCESS_BINFO,
1173 FUNCTIONS, and OPTYPE respectively. */
1176 build_baselink (tree binfo
, tree access_binfo
, tree functions
, tree optype
)
1180 gcc_assert (TREE_CODE (functions
) == FUNCTION_DECL
1181 || TREE_CODE (functions
) == TEMPLATE_DECL
1182 || TREE_CODE (functions
) == TEMPLATE_ID_EXPR
1183 || TREE_CODE (functions
) == OVERLOAD
);
1184 gcc_assert (!optype
|| TYPE_P (optype
));
1185 gcc_assert (TREE_TYPE (functions
));
1187 baselink
= make_node (BASELINK
);
1188 TREE_TYPE (baselink
) = TREE_TYPE (functions
);
1189 BASELINK_BINFO (baselink
) = binfo
;
1190 BASELINK_ACCESS_BINFO (baselink
) = access_binfo
;
1191 BASELINK_FUNCTIONS (baselink
) = functions
;
1192 BASELINK_OPTYPE (baselink
) = optype
;
1197 /* Look for a member named NAME in an inheritance lattice dominated by
1198 XBASETYPE. If PROTECT is 0 or two, we do not check access. If it
1199 is 1, we enforce accessibility. If PROTECT is zero, then, for an
1200 ambiguous lookup, we return NULL. If PROTECT is 1, we issue error
1201 messages about inaccessible or ambiguous lookup. If PROTECT is 2,
1202 we return a TREE_LIST whose TREE_TYPE is error_mark_node and whose
1203 TREE_VALUEs are the list of ambiguous candidates.
1205 WANT_TYPE is 1 when we should only return TYPE_DECLs.
1207 If nothing can be found return NULL_TREE and do not issue an error. */
1210 lookup_member (tree xbasetype
, tree name
, int protect
, bool want_type
)
1212 tree rval
, rval_binfo
= NULL_TREE
;
1213 tree type
= NULL_TREE
, basetype_path
= NULL_TREE
;
1214 struct lookup_field_info lfi
;
1216 /* rval_binfo is the binfo associated with the found member, note,
1217 this can be set with useful information, even when rval is not
1218 set, because it must deal with ALL members, not just non-function
1219 members. It is used for ambiguity checking and the hidden
1220 checks. Whereas rval is only set if a proper (not hidden)
1221 non-function member is found. */
1223 const char *errstr
= 0;
1225 gcc_assert (TREE_CODE (name
) == IDENTIFIER_NODE
);
1227 if (TREE_CODE (xbasetype
) == TREE_BINFO
)
1229 type
= BINFO_TYPE (xbasetype
);
1230 basetype_path
= xbasetype
;
1234 gcc_assert (IS_AGGR_TYPE_CODE (TREE_CODE (xbasetype
)));
1236 xbasetype
= NULL_TREE
;
1239 type
= complete_type (type
);
1241 basetype_path
= TYPE_BINFO (type
);
1246 #ifdef GATHER_STATISTICS
1247 n_calls_lookup_field
++;
1248 #endif /* GATHER_STATISTICS */
1250 memset (&lfi
, 0, sizeof (lfi
));
1253 lfi
.want_type
= want_type
;
1254 dfs_walk_real (basetype_path
, &lookup_field_r
, 0,
1255 &lookup_field_queue_p
, &lfi
);
1257 rval_binfo
= lfi
.rval_binfo
;
1259 type
= BINFO_TYPE (rval_binfo
);
1260 errstr
= lfi
.errstr
;
1262 /* If we are not interested in ambiguities, don't report them;
1263 just return NULL_TREE. */
1264 if (!protect
&& lfi
.ambiguous
)
1270 return lfi
.ambiguous
;
1277 In the case of overloaded function names, access control is
1278 applied to the function selected by overloaded resolution. */
1279 if (rval
&& protect
&& !is_overloaded_fn (rval
))
1280 perform_or_defer_access_check (basetype_path
, rval
);
1282 if (errstr
&& protect
)
1284 error (errstr
, name
, type
);
1286 print_candidates (lfi
.ambiguous
);
1287 rval
= error_mark_node
;
1290 if (rval
&& is_overloaded_fn (rval
))
1291 rval
= build_baselink (rval_binfo
, basetype_path
, rval
,
1292 (IDENTIFIER_TYPENAME_P (name
)
1293 ? TREE_TYPE (name
): NULL_TREE
));
1297 /* Like lookup_member, except that if we find a function member we
1298 return NULL_TREE. */
1301 lookup_field (tree xbasetype
, tree name
, int protect
, bool want_type
)
1303 tree rval
= lookup_member (xbasetype
, name
, protect
, want_type
);
1305 /* Ignore functions, but propagate the ambiguity list. */
1306 if (!error_operand_p (rval
)
1307 && (rval
&& BASELINK_P (rval
)))
1313 /* Like lookup_member, except that if we find a non-function member we
1314 return NULL_TREE. */
1317 lookup_fnfields (tree xbasetype
, tree name
, int protect
)
1319 tree rval
= lookup_member (xbasetype
, name
, protect
, /*want_type=*/false);
1321 /* Ignore non-functions, but propagate the ambiguity list. */
1322 if (!error_operand_p (rval
)
1323 && (rval
&& !BASELINK_P (rval
)))
1329 /* Return the index in the CLASSTYPE_METHOD_VEC for CLASS_TYPE
1330 corresponding to "operator TYPE ()", or -1 if there is no such
1331 operator. Only CLASS_TYPE itself is searched; this routine does
1332 not scan the base classes of CLASS_TYPE. */
1335 lookup_conversion_operator (tree class_type
, tree type
)
1339 if (TYPE_HAS_CONVERSION (class_type
))
1343 VEC(tree
) *methods
= CLASSTYPE_METHOD_VEC (class_type
);
1345 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1346 VEC_iterate (tree
, methods
, i
, fn
); ++i
)
1348 /* All the conversion operators come near the beginning of
1349 the class. Therefore, if FN is not a conversion
1350 operator, there is no matching conversion operator in
1352 fn
= OVL_CURRENT (fn
);
1353 if (!DECL_CONV_FN_P (fn
))
1356 if (TREE_CODE (fn
) == TEMPLATE_DECL
)
1357 /* All the templated conversion functions are on the same
1358 slot, so remember it. */
1360 else if (same_type_p (DECL_CONV_FN_TYPE (fn
), type
))
1368 /* TYPE is a class type. Return the index of the fields within
1369 the method vector with name NAME, or -1 is no such field exists. */
1372 lookup_fnfields_1 (tree type
, tree name
)
1374 VEC(tree
) *method_vec
;
1379 if (!CLASS_TYPE_P (type
))
1382 if (COMPLETE_TYPE_P (type
))
1384 if ((name
== ctor_identifier
1385 || name
== base_ctor_identifier
1386 || name
== complete_ctor_identifier
))
1388 if (CLASSTYPE_LAZY_DEFAULT_CTOR (type
))
1389 lazily_declare_fn (sfk_constructor
, type
);
1390 if (CLASSTYPE_LAZY_COPY_CTOR (type
))
1391 lazily_declare_fn (sfk_copy_constructor
, type
);
1393 else if (name
== ansi_assopname(NOP_EXPR
)
1394 && CLASSTYPE_LAZY_ASSIGNMENT_OP (type
))
1395 lazily_declare_fn (sfk_assignment_operator
, type
);
1398 method_vec
= CLASSTYPE_METHOD_VEC (type
);
1402 #ifdef GATHER_STATISTICS
1403 n_calls_lookup_fnfields_1
++;
1404 #endif /* GATHER_STATISTICS */
1406 /* Constructors are first... */
1407 if (name
== ctor_identifier
)
1409 fn
= CLASSTYPE_CONSTRUCTORS (type
);
1410 return fn
? CLASSTYPE_CONSTRUCTOR_SLOT
: -1;
1412 /* and destructors are second. */
1413 if (name
== dtor_identifier
)
1415 fn
= CLASSTYPE_DESTRUCTORS (type
);
1416 return fn
? CLASSTYPE_DESTRUCTOR_SLOT
: -1;
1418 if (IDENTIFIER_TYPENAME_P (name
))
1419 return lookup_conversion_operator (type
, TREE_TYPE (name
));
1421 /* Skip the conversion operators. */
1422 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
1423 VEC_iterate (tree
, method_vec
, i
, fn
);
1425 if (!DECL_CONV_FN_P (OVL_CURRENT (fn
)))
1428 /* If the type is complete, use binary search. */
1429 if (COMPLETE_TYPE_P (type
))
1435 hi
= VEC_length (tree
, method_vec
);
1440 #ifdef GATHER_STATISTICS
1441 n_outer_fields_searched
++;
1442 #endif /* GATHER_STATISTICS */
1444 tmp
= VEC_index (tree
, method_vec
, i
);
1445 tmp
= DECL_NAME (OVL_CURRENT (tmp
));
1448 else if (tmp
< name
)
1455 for (; VEC_iterate (tree
, method_vec
, i
, fn
); ++i
)
1457 #ifdef GATHER_STATISTICS
1458 n_outer_fields_searched
++;
1459 #endif /* GATHER_STATISTICS */
1460 if (DECL_NAME (OVL_CURRENT (fn
)) == name
)
1467 /* Like lookup_fnfields_1, except that the name is extracted from
1468 FUNCTION, which is a FUNCTION_DECL or a TEMPLATE_DECL. */
1471 class_method_index_for_fn (tree class_type
, tree function
)
1473 gcc_assert (TREE_CODE (function
) == FUNCTION_DECL
1474 || DECL_FUNCTION_TEMPLATE_P (function
));
1476 return lookup_fnfields_1 (class_type
,
1477 DECL_CONSTRUCTOR_P (function
) ? ctor_identifier
:
1478 DECL_DESTRUCTOR_P (function
) ? dtor_identifier
:
1479 DECL_NAME (function
));
1483 /* DECL is the result of a qualified name lookup. QUALIFYING_SCOPE is
1484 the class or namespace used to qualify the name. CONTEXT_CLASS is
1485 the class corresponding to the object in which DECL will be used.
1486 Return a possibly modified version of DECL that takes into account
1489 In particular, consider an expression like `B::m' in the context of
1490 a derived class `D'. If `B::m' has been resolved to a BASELINK,
1491 then the most derived class indicated by the BASELINK_BINFO will be
1492 `B', not `D'. This function makes that adjustment. */
1495 adjust_result_of_qualified_name_lookup (tree decl
,
1496 tree qualifying_scope
,
1499 if (context_class
&& CLASS_TYPE_P (qualifying_scope
)
1500 && DERIVED_FROM_P (qualifying_scope
, context_class
)
1501 && BASELINK_P (decl
))
1505 gcc_assert (CLASS_TYPE_P (context_class
));
1507 /* Look for the QUALIFYING_SCOPE as a base of the CONTEXT_CLASS.
1508 Because we do not yet know which function will be chosen by
1509 overload resolution, we cannot yet check either accessibility
1510 or ambiguity -- in either case, the choice of a static member
1511 function might make the usage valid. */
1512 base
= lookup_base (context_class
, qualifying_scope
,
1513 ba_ignore
| ba_quiet
, NULL
);
1516 BASELINK_ACCESS_BINFO (decl
) = base
;
1517 BASELINK_BINFO (decl
)
1518 = lookup_base (base
, BINFO_TYPE (BASELINK_BINFO (decl
)),
1519 ba_ignore
| ba_quiet
,
1528 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
1529 PREFN is called in preorder, while POSTFN is called in postorder.
1530 If they ever returns a non-NULL value, that value is immediately
1531 returned and the walk is terminated. Both PREFN and POSTFN can be
1532 NULL. At each node, PREFN and POSTFN are passed the binfo to
1533 examine. Before each base-binfo of BINFO is walked, QFN is called.
1534 If the value returned is nonzero, the base-binfo is walked;
1535 otherwise it is not. If QFN is NULL, it is treated as a function
1536 which always returns 1. All callbacks are passed DATA whenever
1540 dfs_walk_real (tree binfo
,
1541 tree (*prefn
) (tree
, void *),
1542 tree (*postfn
) (tree
, void *),
1543 tree (*qfn
) (tree
, int, void *),
1548 tree rval
= NULL_TREE
;
1550 /* Call the pre-order walking function. */
1553 rval
= (*prefn
) (binfo
, data
);
1558 /* Process the basetypes. */
1559 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
1563 base_binfo
= (*qfn
) (binfo
, i
, data
);
1567 rval
= dfs_walk_real (base_binfo
, prefn
, postfn
, qfn
, data
);
1572 /* Call the post-order walking function. */
1574 rval
= (*postfn
) (binfo
, data
);
1579 /* Exactly like dfs_walk_real, except that there is no pre-order
1580 function call and FN is called in post-order. */
1583 dfs_walk (tree binfo
,
1584 tree (*fn
) (tree
, void *),
1585 tree (*qfn
) (tree
, int, void *),
1588 return dfs_walk_real (binfo
, 0, fn
, qfn
, data
);
1591 /* Check that virtual overrider OVERRIDER is acceptable for base function
1592 BASEFN. Issue diagnostic, and return zero, if unacceptable. */
1595 check_final_overrider (tree overrider
, tree basefn
)
1597 tree over_type
= TREE_TYPE (overrider
);
1598 tree base_type
= TREE_TYPE (basefn
);
1599 tree over_return
= TREE_TYPE (over_type
);
1600 tree base_return
= TREE_TYPE (base_type
);
1601 tree over_throw
= TYPE_RAISES_EXCEPTIONS (over_type
);
1602 tree base_throw
= TYPE_RAISES_EXCEPTIONS (base_type
);
1605 if (DECL_INVALID_OVERRIDER_P (overrider
))
1608 if (same_type_p (base_return
, over_return
))
1610 else if ((CLASS_TYPE_P (over_return
) && CLASS_TYPE_P (base_return
))
1611 || (TREE_CODE (base_return
) == TREE_CODE (over_return
)
1612 && POINTER_TYPE_P (base_return
)))
1614 /* Potentially covariant. */
1615 unsigned base_quals
, over_quals
;
1617 fail
= !POINTER_TYPE_P (base_return
);
1620 fail
= cp_type_quals (base_return
) != cp_type_quals (over_return
);
1622 base_return
= TREE_TYPE (base_return
);
1623 over_return
= TREE_TYPE (over_return
);
1625 base_quals
= cp_type_quals (base_return
);
1626 over_quals
= cp_type_quals (over_return
);
1628 if ((base_quals
& over_quals
) != over_quals
)
1631 if (CLASS_TYPE_P (base_return
) && CLASS_TYPE_P (over_return
))
1633 tree binfo
= lookup_base (over_return
, base_return
,
1634 ba_check
| ba_quiet
, NULL
);
1640 && can_convert (TREE_TYPE (base_type
), TREE_TYPE (over_type
)))
1641 /* GNU extension, allow trivial pointer conversions such as
1642 converting to void *, or qualification conversion. */
1644 /* can_convert will permit user defined conversion from a
1645 (reference to) class type. We must reject them. */
1646 over_return
= non_reference (TREE_TYPE (over_type
));
1647 if (CLASS_TYPE_P (over_return
))
1661 cp_error_at ("invalid covariant return type for `%#D'", overrider
);
1662 cp_error_at (" overriding `%#D'", basefn
);
1666 cp_error_at ("conflicting return type specified for `%#D'",
1668 cp_error_at (" overriding `%#D'", basefn
);
1670 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1674 /* Check throw specifier is at least as strict. */
1675 if (!comp_except_specs (base_throw
, over_throw
, 0))
1677 cp_error_at ("looser throw specifier for `%#F'", overrider
);
1678 cp_error_at (" overriding `%#F'", basefn
);
1679 DECL_INVALID_OVERRIDER_P (overrider
) = 1;
1686 /* Given a class TYPE, and a function decl FNDECL, look for
1687 virtual functions in TYPE's hierarchy which FNDECL overrides.
1688 We do not look in TYPE itself, only its bases.
1690 Returns nonzero, if we find any. Set FNDECL's DECL_VIRTUAL_P, if we
1691 find that it overrides anything.
1693 We check that every function which is overridden, is correctly
1697 look_for_overrides (tree type
, tree fndecl
)
1699 tree binfo
= TYPE_BINFO (type
);
1704 for (ix
= 0; BINFO_BASE_ITERATE (binfo
, ix
, base_binfo
); ix
++)
1706 tree basetype
= BINFO_TYPE (base_binfo
);
1708 if (TYPE_POLYMORPHIC_P (basetype
))
1709 found
+= look_for_overrides_r (basetype
, fndecl
);
1714 /* Look in TYPE for virtual functions with the same signature as
1718 look_for_overrides_here (tree type
, tree fndecl
)
1722 /* If there are no methods in TYPE (meaning that only implicitly
1723 declared methods will ever be provided for TYPE), then there are
1724 no virtual functions. */
1725 if (!CLASSTYPE_METHOD_VEC (type
))
1728 if (DECL_MAYBE_IN_CHARGE_DESTRUCTOR_P (fndecl
))
1729 ix
= CLASSTYPE_DESTRUCTOR_SLOT
;
1731 ix
= lookup_fnfields_1 (type
, DECL_NAME (fndecl
));
1734 tree fns
= VEC_index (tree
, CLASSTYPE_METHOD_VEC (type
), ix
);
1736 for (; fns
; fns
= OVL_NEXT (fns
))
1738 tree fn
= OVL_CURRENT (fns
);
1740 if (!DECL_VIRTUAL_P (fn
))
1741 /* Not a virtual. */;
1742 else if (DECL_CONTEXT (fn
) != type
)
1743 /* Introduced with a using declaration. */;
1744 else if (DECL_STATIC_FUNCTION_P (fndecl
))
1746 tree btypes
= TYPE_ARG_TYPES (TREE_TYPE (fn
));
1747 tree dtypes
= TYPE_ARG_TYPES (TREE_TYPE (fndecl
));
1748 if (compparms (TREE_CHAIN (btypes
), dtypes
))
1751 else if (same_signature_p (fndecl
, fn
))
1758 /* Look in TYPE for virtual functions overridden by FNDECL. Check both
1759 TYPE itself and its bases. */
1762 look_for_overrides_r (tree type
, tree fndecl
)
1764 tree fn
= look_for_overrides_here (type
, fndecl
);
1767 if (DECL_STATIC_FUNCTION_P (fndecl
))
1769 /* A static member function cannot match an inherited
1770 virtual member function. */
1771 cp_error_at ("`%#D' cannot be declared", fndecl
);
1772 cp_error_at (" since `%#D' declared in base class", fn
);
1776 /* It's definitely virtual, even if not explicitly set. */
1777 DECL_VIRTUAL_P (fndecl
) = 1;
1778 check_final_overrider (fndecl
, fn
);
1783 /* We failed to find one declared in this class. Look in its bases. */
1784 return look_for_overrides (type
, fndecl
);
1787 /* Called via dfs_walk from dfs_get_pure_virtuals. */
1790 dfs_get_pure_virtuals (tree binfo
, void *data
)
1792 tree type
= (tree
) data
;
1794 /* We're not interested in primary base classes; the derived class
1795 of which they are a primary base will contain the information we
1797 if (!BINFO_PRIMARY_P (binfo
))
1801 for (virtuals
= BINFO_VIRTUALS (binfo
);
1803 virtuals
= TREE_CHAIN (virtuals
))
1804 if (DECL_PURE_VIRTUAL_P (BV_FN (virtuals
)))
1805 VEC_safe_push (tree
, CLASSTYPE_PURE_VIRTUALS (type
),
1809 BINFO_MARKED (binfo
) = 1;
1814 /* Set CLASSTYPE_PURE_VIRTUALS for TYPE. */
1817 get_pure_virtuals (tree type
)
1819 /* Clear the CLASSTYPE_PURE_VIRTUALS list; whatever is already there
1820 is going to be overridden. */
1821 CLASSTYPE_PURE_VIRTUALS (type
) = NULL
;
1822 /* Now, run through all the bases which are not primary bases, and
1823 collect the pure virtual functions. We look at the vtable in
1824 each class to determine what pure virtual functions are present.
1825 (A primary base is not interesting because the derived class of
1826 which it is a primary base will contain vtable entries for the
1827 pure virtuals in the base class. */
1828 dfs_walk (TYPE_BINFO (type
), dfs_get_pure_virtuals
, unmarkedp
, type
);
1829 dfs_walk (TYPE_BINFO (type
), dfs_unmark
, markedp
, type
);
1832 /* DEPTH-FIRST SEARCH ROUTINES. */
1835 markedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1837 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1839 return BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1843 unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1845 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1847 return !BINFO_MARKED (binfo
) ? binfo
: NULL_TREE
;
1850 /* The worker functions for `dfs_walk'. These do not need to
1851 test anything (vis a vis marking) if they are paired with
1852 a predicate function (above). */
1855 dfs_unmark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1857 BINFO_MARKED (binfo
) = 0;
1862 /* Debug info for C++ classes can get very large; try to avoid
1863 emitting it everywhere.
1865 Note that this optimization wins even when the target supports
1866 BINCL (if only slightly), and reduces the amount of work for the
1870 maybe_suppress_debug_info (tree t
)
1872 if (write_symbols
== NO_DEBUG
)
1875 /* We might have set this earlier in cp_finish_decl. */
1876 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 0;
1878 /* If we already know how we're handling this class, handle debug info
1880 if (CLASSTYPE_INTERFACE_KNOWN (t
))
1882 if (CLASSTYPE_INTERFACE_ONLY (t
))
1883 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1884 /* else don't set it. */
1886 /* If the class has a vtable, write out the debug info along with
1888 else if (TYPE_CONTAINS_VPTR_P (t
))
1889 TYPE_DECL_SUPPRESS_DEBUG (TYPE_MAIN_DECL (t
)) = 1;
1891 /* Otherwise, just emit the debug info normally. */
1894 /* Note that we want debugging information for a base class of a class
1895 whose vtable is being emitted. Normally, this would happen because
1896 calling the constructor for a derived class implies calling the
1897 constructors for all bases, which involve initializing the
1898 appropriate vptr with the vtable for the base class; but in the
1899 presence of optimization, this initialization may be optimized
1900 away, so we tell finish_vtable_vardecl that we want the debugging
1901 information anyway. */
1904 dfs_debug_mark (tree binfo
, void *data ATTRIBUTE_UNUSED
)
1906 tree t
= BINFO_TYPE (binfo
);
1908 CLASSTYPE_DEBUG_REQUESTED (t
) = 1;
1913 /* Returns BINFO if we haven't already noted that we want debugging
1914 info for this base class. */
1917 dfs_debug_unmarkedp (tree derived
, int ix
, void *data ATTRIBUTE_UNUSED
)
1919 tree binfo
= BINFO_BASE_BINFO (derived
, ix
);
1921 return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo
))
1922 ? binfo
: NULL_TREE
);
1925 /* Write out the debugging information for TYPE, whose vtable is being
1926 emitted. Also walk through our bases and note that we want to
1927 write out information for them. This avoids the problem of not
1928 writing any debug info for intermediate basetypes whose
1929 constructors, and thus the references to their vtables, and thus
1930 the vtables themselves, were optimized away. */
1933 note_debug_info_needed (tree type
)
1935 if (TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)))
1937 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (type
)) = 0;
1938 rest_of_type_compilation (type
, toplevel_bindings_p ());
1941 dfs_walk (TYPE_BINFO (type
), dfs_debug_mark
, dfs_debug_unmarkedp
, 0);
1945 print_search_statistics (void)
1947 #ifdef GATHER_STATISTICS
1948 fprintf (stderr
, "%d fields searched in %d[%d] calls to lookup_field[_1]\n",
1949 n_fields_searched
, n_calls_lookup_field
, n_calls_lookup_field_1
);
1950 fprintf (stderr
, "%d fnfields searched in %d calls to lookup_fnfields\n",
1951 n_outer_fields_searched
, n_calls_lookup_fnfields
);
1952 fprintf (stderr
, "%d calls to get_base_type\n", n_calls_get_base_type
);
1953 #else /* GATHER_STATISTICS */
1954 fprintf (stderr
, "no search statistics\n");
1955 #endif /* GATHER_STATISTICS */
1959 reinit_search_statistics (void)
1961 #ifdef GATHER_STATISTICS
1962 n_fields_searched
= 0;
1963 n_calls_lookup_field
= 0, n_calls_lookup_field_1
= 0;
1964 n_calls_lookup_fnfields
= 0, n_calls_lookup_fnfields_1
= 0;
1965 n_calls_get_base_type
= 0;
1966 n_outer_fields_searched
= 0;
1967 n_contexts_saved
= 0;
1968 #endif /* GATHER_STATISTICS */
1971 /* Helper for lookup_conversions_r. TO_TYPE is the type converted to
1972 by a conversion op in base BINFO. VIRTUAL_DEPTH is nonzero if
1973 BINFO is morally virtual, and VIRTUALNESS is nonzero if virtual
1974 bases have been encountered already in the tree walk. PARENT_CONVS
1975 is the list of lists of conversion functions that could hide CONV
1976 and OTHER_CONVS is the list of lists of conversion functions that
1977 could hide or be hidden by CONV, should virtualness be involved in
1978 the hierarchy. Merely checking the conversion op's name is not
1979 enough because two conversion operators to the same type can have
1980 different names. Return nonzero if we are visible. */
1983 check_hidden_convs (tree binfo
, int virtual_depth
, int virtualness
,
1984 tree to_type
, tree parent_convs
, tree other_convs
)
1988 /* See if we are hidden by a parent conversion. */
1989 for (level
= parent_convs
; level
; level
= TREE_CHAIN (level
))
1990 for (probe
= TREE_VALUE (level
); probe
; probe
= TREE_CHAIN (probe
))
1991 if (same_type_p (to_type
, TREE_TYPE (probe
)))
1994 if (virtual_depth
|| virtualness
)
1996 /* In a virtual hierarchy, we could be hidden, or could hide a
1997 conversion function on the other_convs list. */
1998 for (level
= other_convs
; level
; level
= TREE_CHAIN (level
))
2004 if (!(virtual_depth
|| TREE_STATIC (level
)))
2005 /* Neither is morally virtual, so cannot hide each other. */
2008 if (!TREE_VALUE (level
))
2009 /* They evaporated away already. */
2012 they_hide_us
= (virtual_depth
2013 && original_binfo (binfo
, TREE_PURPOSE (level
)));
2014 we_hide_them
= (!they_hide_us
&& TREE_STATIC (level
)
2015 && original_binfo (TREE_PURPOSE (level
), binfo
));
2017 if (!(we_hide_them
|| they_hide_us
))
2018 /* Neither is within the other, so no hiding can occur. */
2021 for (prev
= &TREE_VALUE (level
), other
= *prev
; other
;)
2023 if (same_type_p (to_type
, TREE_TYPE (other
)))
2026 /* We are hidden. */
2031 /* We hide the other one. */
2032 other
= TREE_CHAIN (other
);
2037 prev
= &TREE_CHAIN (other
);
2045 /* Helper for lookup_conversions_r. PARENT_CONVS is a list of lists
2046 of conversion functions, the first slot will be for the current
2047 binfo, if MY_CONVS is non-NULL. CHILD_CONVS is the list of lists
2048 of conversion functions from children of the current binfo,
2049 concatenated with conversions from elsewhere in the hierarchy --
2050 that list begins with OTHER_CONVS. Return a single list of lists
2051 containing only conversions from the current binfo and its
2055 split_conversions (tree my_convs
, tree parent_convs
,
2056 tree child_convs
, tree other_convs
)
2061 /* Remove the original other_convs portion from child_convs. */
2062 for (prev
= NULL
, t
= child_convs
;
2063 t
!= other_convs
; prev
= t
, t
= TREE_CHAIN (t
))
2067 TREE_CHAIN (prev
) = NULL_TREE
;
2069 child_convs
= NULL_TREE
;
2071 /* Attach the child convs to any we had at this level. */
2074 my_convs
= parent_convs
;
2075 TREE_CHAIN (my_convs
) = child_convs
;
2078 my_convs
= child_convs
;
2083 /* Worker for lookup_conversions. Lookup conversion functions in
2084 BINFO and its children. VIRTUAL_DEPTH is nonzero, if BINFO is in
2085 a morally virtual base, and VIRTUALNESS is nonzero, if we've
2086 encountered virtual bases already in the tree walk. PARENT_CONVS &
2087 PARENT_TPL_CONVS are lists of list of conversions within parent
2088 binfos. OTHER_CONVS and OTHER_TPL_CONVS are conversions found
2089 elsewhere in the tree. Return the conversions found within this
2090 portion of the graph in CONVS and TPL_CONVS. Return nonzero is we
2091 encountered virtualness. We keep template and non-template
2092 conversions separate, to avoid unnecessary type comparisons.
2094 The located conversion functions are held in lists of lists. The
2095 TREE_VALUE of the outer list is the list of conversion functions
2096 found in a particular binfo. The TREE_PURPOSE of both the outer
2097 and inner lists is the binfo at which those conversions were
2098 found. TREE_STATIC is set for those lists within of morally
2099 virtual binfos. The TREE_VALUE of the inner list is the conversion
2100 function or overload itself. The TREE_TYPE of each inner list node
2101 is the converted-to type. */
2104 lookup_conversions_r (tree binfo
,
2105 int virtual_depth
, int virtualness
,
2106 tree parent_convs
, tree parent_tpl_convs
,
2107 tree other_convs
, tree other_tpl_convs
,
2108 tree
*convs
, tree
*tpl_convs
)
2110 int my_virtualness
= 0;
2111 tree my_convs
= NULL_TREE
;
2112 tree my_tpl_convs
= NULL_TREE
;
2113 tree child_convs
= NULL_TREE
;
2114 tree child_tpl_convs
= NULL_TREE
;
2117 VEC(tree
) *method_vec
= CLASSTYPE_METHOD_VEC (BINFO_TYPE (binfo
));
2120 /* If we have no conversion operators, then don't look. */
2121 if (!TYPE_HAS_CONVERSION (BINFO_TYPE (binfo
)))
2123 *convs
= *tpl_convs
= NULL_TREE
;
2128 if (BINFO_VIRTUAL_P (binfo
))
2131 /* First, locate the unhidden ones at this level. */
2132 for (i
= CLASSTYPE_FIRST_CONVERSION_SLOT
;
2133 VEC_iterate (tree
, method_vec
, i
, conv
);
2136 tree cur
= OVL_CURRENT (conv
);
2138 if (!DECL_CONV_FN_P (cur
))
2141 if (TREE_CODE (cur
) == TEMPLATE_DECL
)
2143 /* Only template conversions can be overloaded, and we must
2144 flatten them out and check each one individually. */
2147 for (tpls
= conv
; tpls
; tpls
= OVL_NEXT (tpls
))
2149 tree tpl
= OVL_CURRENT (tpls
);
2150 tree type
= DECL_CONV_FN_TYPE (tpl
);
2152 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2153 type
, parent_tpl_convs
, other_tpl_convs
))
2155 my_tpl_convs
= tree_cons (binfo
, tpl
, my_tpl_convs
);
2156 TREE_TYPE (my_tpl_convs
) = type
;
2159 TREE_STATIC (my_tpl_convs
) = 1;
2167 tree name
= DECL_NAME (cur
);
2169 if (!IDENTIFIER_MARKED (name
))
2171 tree type
= DECL_CONV_FN_TYPE (cur
);
2173 if (check_hidden_convs (binfo
, virtual_depth
, virtualness
,
2174 type
, parent_convs
, other_convs
))
2176 my_convs
= tree_cons (binfo
, conv
, my_convs
);
2177 TREE_TYPE (my_convs
) = type
;
2180 TREE_STATIC (my_convs
) = 1;
2183 IDENTIFIER_MARKED (name
) = 1;
2191 parent_convs
= tree_cons (binfo
, my_convs
, parent_convs
);
2193 TREE_STATIC (parent_convs
) = 1;
2198 parent_tpl_convs
= tree_cons (binfo
, my_tpl_convs
, parent_tpl_convs
);
2200 TREE_STATIC (parent_convs
) = 1;
2203 child_convs
= other_convs
;
2204 child_tpl_convs
= other_tpl_convs
;
2206 /* Now iterate over each base, looking for more conversions. */
2207 for (i
= 0; BINFO_BASE_ITERATE (binfo
, i
, base_binfo
); i
++)
2209 tree base_convs
, base_tpl_convs
;
2210 unsigned base_virtualness
;
2212 base_virtualness
= lookup_conversions_r (base_binfo
,
2213 virtual_depth
, virtualness
,
2214 parent_convs
, parent_tpl_convs
,
2215 child_convs
, child_tpl_convs
,
2216 &base_convs
, &base_tpl_convs
);
2217 if (base_virtualness
)
2218 my_virtualness
= virtualness
= 1;
2219 child_convs
= chainon (base_convs
, child_convs
);
2220 child_tpl_convs
= chainon (base_tpl_convs
, child_tpl_convs
);
2223 /* Unmark the conversions found at this level */
2224 for (conv
= my_convs
; conv
; conv
= TREE_CHAIN (conv
))
2225 IDENTIFIER_MARKED (DECL_NAME (OVL_CURRENT (TREE_VALUE (conv
)))) = 0;
2227 *convs
= split_conversions (my_convs
, parent_convs
,
2228 child_convs
, other_convs
);
2229 *tpl_convs
= split_conversions (my_tpl_convs
, parent_tpl_convs
,
2230 child_tpl_convs
, other_tpl_convs
);
2232 return my_virtualness
;
2235 /* Return a TREE_LIST containing all the non-hidden user-defined
2236 conversion functions for TYPE (and its base-classes). The
2237 TREE_VALUE of each node is the FUNCTION_DECL of the conversion
2238 function. The TREE_PURPOSE is the BINFO from which the conversion
2239 functions in this node were selected. This function is effectively
2240 performing a set of member lookups as lookup_fnfield does, but
2241 using the type being converted to as the unique key, rather than the
2245 lookup_conversions (tree type
)
2247 tree convs
, tpl_convs
;
2248 tree list
= NULL_TREE
;
2250 complete_type (type
);
2251 if (!TYPE_BINFO (type
))
2254 lookup_conversions_r (TYPE_BINFO (type
), 0, 0,
2255 NULL_TREE
, NULL_TREE
, NULL_TREE
, NULL_TREE
,
2256 &convs
, &tpl_convs
);
2258 /* Flatten the list-of-lists */
2259 for (; convs
; convs
= TREE_CHAIN (convs
))
2263 for (probe
= TREE_VALUE (convs
); probe
; probe
= next
)
2265 next
= TREE_CHAIN (probe
);
2267 TREE_CHAIN (probe
) = list
;
2272 for (; tpl_convs
; tpl_convs
= TREE_CHAIN (tpl_convs
))
2276 for (probe
= TREE_VALUE (tpl_convs
); probe
; probe
= next
)
2278 next
= TREE_CHAIN (probe
);
2280 TREE_CHAIN (probe
) = list
;
2288 /* Returns the binfo of the first direct or indirect virtual base derived
2289 from BINFO, or NULL if binfo is not via virtual. */
2292 binfo_from_vbase (tree binfo
)
2294 for (; binfo
; binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2296 if (BINFO_VIRTUAL_P (binfo
))
2302 /* Returns the binfo of the first direct or indirect virtual base derived
2303 from BINFO up to the TREE_TYPE, LIMIT, or NULL if binfo is not
2307 binfo_via_virtual (tree binfo
, tree limit
)
2309 for (; binfo
&& (!limit
|| !same_type_p (BINFO_TYPE (binfo
), limit
));
2310 binfo
= BINFO_INHERITANCE_CHAIN (binfo
))
2312 if (BINFO_VIRTUAL_P (binfo
))
2318 /* BINFO is a base binfo in the complete type BINFO_TYPE (HERE).
2319 Find the equivalent binfo within whatever graph HERE is located.
2320 This is the inverse of original_binfo. */
2323 copied_binfo (tree binfo
, tree here
)
2325 tree result
= NULL_TREE
;
2327 if (BINFO_VIRTUAL_P (binfo
))
2331 for (t
= here
; BINFO_INHERITANCE_CHAIN (t
);
2332 t
= BINFO_INHERITANCE_CHAIN (t
))
2335 result
= binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (t
));
2337 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2343 cbinfo
= copied_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2344 for (ix
= 0; BINFO_BASE_ITERATE (cbinfo
, ix
, base_binfo
); ix
++)
2345 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2347 result
= base_binfo
;
2353 gcc_assert (BINFO_TYPE (here
) == BINFO_TYPE (binfo
));
2357 gcc_assert (result
);
2362 binfo_for_vbase (tree base
, tree t
)
2368 for (vbases
= CLASSTYPE_VBASECLASSES (t
), ix
= 0;
2369 VEC_iterate (tree
, vbases
, ix
, binfo
); ix
++)
2370 if (BINFO_TYPE (binfo
) == base
)
2375 /* BINFO is some base binfo of HERE, within some other
2376 hierarchy. Return the equivalent binfo, but in the hierarchy
2377 dominated by HERE. This is the inverse of copied_binfo. If BINFO
2378 is not a base binfo of HERE, returns NULL_TREE. */
2381 original_binfo (tree binfo
, tree here
)
2385 if (BINFO_TYPE (binfo
) == BINFO_TYPE (here
))
2387 else if (BINFO_VIRTUAL_P (binfo
))
2388 result
= (CLASSTYPE_VBASECLASSES (BINFO_TYPE (here
))
2389 ? binfo_for_vbase (BINFO_TYPE (binfo
), BINFO_TYPE (here
))
2391 else if (BINFO_INHERITANCE_CHAIN (binfo
))
2395 base_binfos
= original_binfo (BINFO_INHERITANCE_CHAIN (binfo
), here
);
2401 for (ix
= 0; (base_binfo
= BINFO_BASE_BINFO (base_binfos
, ix
)); ix
++)
2402 if (BINFO_TYPE (base_binfo
) == BINFO_TYPE (binfo
))
2404 result
= base_binfo
;