1 files changed, 230 insertions, 174 deletions

diff --git a/gcc/cp/search.c b/gcc/cp/search.c
index 47d08f34c74..cd6e9b2dc65 100644
--- a/gcc/cp/search.c
+++ b/gcc/cp/search.c
@@ -36,29 +36,20 @@ Boston, MA 02111-1307, USA.  */
 #include "toplev.h"
 #include "stack.h"
 
-struct vbase_info 
-{
-  /* The class dominating the hierarchy.  */
-  tree type;
-  /* A pointer to a complete object of the indicated TYPE.  */
-  tree decl_ptr;
-  tree inits;
-};
-
 static int is_subobject_of_p (tree, tree);
 static base_kind lookup_base_r (tree, tree, base_access, bool, tree *);
 static int dynamic_cast_base_recurse (tree, tree, bool, tree *);
-static tree dfs_debug_unmarkedp (tree, int, void *);
 static tree dfs_debug_mark (tree, void *);
+static tree dfs_walk_once_r (tree, tree (*pre_fn) (tree, void *),
+			     tree (*post_fn) (tree, void *), void *data);
+static void dfs_unmark_r (tree);
 static int check_hidden_convs (tree, int, int, tree, tree, tree);
 static tree split_conversions (tree, tree, tree, tree);
 static int lookup_conversions_r (tree, int, int,
 				 tree, tree, tree, tree, tree *, tree *);
 static int look_for_overrides_r (tree, tree);
-static tree lookup_field_queue_p (tree, int, void *);
 static tree lookup_field_r (tree, void *);
-static tree dfs_accessible_queue_p (tree, int, void *);
-static tree dfs_accessible_p (tree, void *);
+static tree accessible_r (tree, bool);
 static tree dfs_access_in_type (tree, void *);
 static access_kind access_in_type (tree, tree);
 static int protected_accessible_p (tree, tree, tree);
@@ -663,10 +654,6 @@ dfs_access_in_type (tree binfo, void *data)
   /* Note the access to DECL in TYPE.  */
   SET_BINFO_ACCESS (binfo, access);
 
-  /* Mark TYPE as visited so that if we reach it again we do not
-     duplicate our efforts here.  */
-  BINFO_MARKED (binfo) = 1;
-
   return NULL_TREE;
 }
 
@@ -688,47 +675,11 @@ access_in_type (tree type, tree decl)
     The algorithm we use is to make a post-order depth-first traversal
     of the base-class hierarchy.  As we come up the tree, we annotate
     each node with the most lenient access.  */
-  dfs_walk_real (binfo, 0, dfs_access_in_type, unmarkedp, decl);
-  dfs_walk (binfo, dfs_unmark, markedp,  0);
+  dfs_walk_once (binfo, NULL, dfs_access_in_type, decl);
 
   return BINFO_ACCESS (binfo);
 }
 
-/* Called from accessible_p via dfs_walk.  */
-
-static tree
-dfs_accessible_queue_p (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
-{
-  tree binfo = BINFO_BASE_BINFO (derived, ix);
-  
-  if (BINFO_MARKED (binfo))
-    return NULL_TREE;
-
-  /* If this class is inherited via private or protected inheritance,
-     then we can't see it, unless we are a friend of the derived class.  */
-  if (BINFO_BASE_ACCESS (derived, ix) != access_public_node
-      && !is_friend (BINFO_TYPE (derived), current_scope ()))
-    return NULL_TREE;
-
-  return binfo;
-}
-
-/* Called from accessible_p via dfs_walk.  */
-
-static tree
-dfs_accessible_p (tree binfo, void *data ATTRIBUTE_UNUSED)
-{
-  access_kind access;
-
-  BINFO_MARKED (binfo) = 1;
-  access = BINFO_ACCESS (binfo);
-  if (access != ak_none
-      && is_friend (BINFO_TYPE (binfo), current_scope ()))
-    return binfo;
-
-  return NULL_TREE;
-}
-
 /* Returns nonzero if it is OK to access DECL through an object
    indicated by BINFO in the context of DERIVED.  */
 
@@ -855,6 +806,43 @@ friend_accessible_p (tree scope, tree decl, tree binfo)
   return 0;
 }
 
+static tree
+accessible_r (tree binfo, bool once)
+{
+  tree rval = NULL_TREE;
+  unsigned ix;
+  tree base_binfo;
+  
+  /* Find the next child binfo to walk.  */
+  for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
+    {
+      bool mark = once && BINFO_VIRTUAL_P (base_binfo);
+
+      if (mark && BINFO_MARKED (base_binfo))
+	continue;
+  
+      /* If the base is inherited via private or protected
+     	 inheritance, then we can't see it, unless we are a friend of
+     	 the current binfo.  */
+      if (BINFO_BASE_ACCESS (binfo, ix) != access_public_node
+	  && !is_friend (BINFO_TYPE (binfo), current_scope ()))
+	continue;
+
+      if (mark)
+	BINFO_MARKED (base_binfo) = 1;
+
+      rval = accessible_r (base_binfo, once);
+      if (rval)
+	return rval;
+    }
+  
+  if (BINFO_ACCESS (binfo) != ak_none
+      && is_friend (BINFO_TYPE (binfo), current_scope ()))
+    rval = binfo;
+  
+  return rval;
+}
+
 /* DECL is a declaration from a base class of TYPE, which was the
    class used to name DECL.  Return nonzero if, in the current
    context, DECL is accessible.  If TYPE is actually a BINFO node,
@@ -941,12 +929,28 @@ accessible_p (tree type, tree decl)
     {
       /* Walk the hierarchy again, looking for a base class that allows
 	 access.  */
-      t = dfs_walk (binfo, dfs_accessible_p, dfs_accessible_queue_p, 0);
-      /* Clear any mark bits.  Note that we have to walk the whole tree
-	 here, since we have aborted the previous walk from some point
-	 deep in the tree.  */
-      dfs_walk (binfo, dfs_unmark, 0,  0);
+      t = accessible_r
+	(binfo, CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)));
 
+      if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)))
+	;/* We are not diamond shaped, and therefore cannot
+	    encounter the same binfo twice.  */
+      else if (!BINFO_INHERITANCE_CHAIN (binfo))
+	{
+	  /* We are at the top of the hierarchy, and can use the
+             CLASSTYPE_VBASECLASSES list for unmarking the virtual
+             bases.  */
+	  VEC (tree) *vbases;
+	  unsigned ix;
+	  tree base_binfo;
+	  
+	  for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0;
+	       VEC_iterate (tree, vbases, ix, base_binfo); ix++)
+	    BINFO_MARKED (base_binfo) = 0;
+	}
+      else
+	dfs_unmark_r (binfo);
+      
       return t != NULL_TREE;
     }
 }
@@ -969,33 +973,6 @@ struct lookup_field_info {
   const char *errstr;
 };
 
-/* Returns nonzero if BINFO is not hidden by the value found by the
-   lookup so far.  If BINFO is hidden, then there's no need to look in
-   it.  DATA is really a struct lookup_field_info.  Called from
-   lookup_field via breadth_first_search.  */
-
-static tree
-lookup_field_queue_p (tree derived, int ix, void *data)
-{
-  tree binfo = BINFO_BASE_BINFO (derived, ix);
-  struct lookup_field_info *lfi = (struct lookup_field_info *) data;
-
-  /* Don't look for constructors or destructors in base classes.  */
-  if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
-    return NULL_TREE;
-
-  /* If this base class is hidden by the best-known value so far, we
-     don't need to look.  */
-  if (lfi->rval_binfo && derived == lfi->rval_binfo)
-    return NULL_TREE;
-
-  /* If this is a dependent base, don't look in it.  */
-  if (BINFO_DEPENDENT_BASE_P (binfo))
-    return NULL_TREE;
-  
-  return binfo;
-}
-
 /* Within the scope of a template class, you can refer to the to the
    current specialization with the name of the template itself.  For
    example:
@@ -1075,6 +1052,16 @@ lookup_field_r (tree binfo, void *data)
   tree type = BINFO_TYPE (binfo);
   tree nval = NULL_TREE;
 
+  /* If this is a dependent base, don't look in it.  */
+  if (BINFO_DEPENDENT_BASE_P (binfo))
+    return NULL_TREE;
+  
+  /* If this base class is hidden by the best-known value so far, we
+     don't need to look.  */
+  if (lfi->rval_binfo && BINFO_INHERITANCE_CHAIN (binfo) == lfi->rval_binfo
+      && !BINFO_VIRTUAL_P (binfo))
+    return dfs_skip_bases;
+
   /* First, look for a function.  There can't be a function and a data
      member with the same name, and if there's a function and a type
      with the same name, the type is hidden by the function.  */
@@ -1092,7 +1079,7 @@ lookup_field_r (tree binfo, void *data)
   /* If there is no declaration with the indicated name in this type,
      then there's nothing to do.  */
   if (!nval)
-    return NULL_TREE;
+    goto done;
 
   /* If we're looking up a type (as with an elaborated type specifier)
      we ignore all non-types we find.  */
@@ -1119,14 +1106,14 @@ lookup_field_r (tree binfo, void *data)
 	  if (e != NULL)
 	    nval = TYPE_MAIN_DECL (e->type);
 	  else 
-	    return NULL_TREE;
+	    goto done;
 	}
     }
 
   /* You must name a template base class with a template-id.  */
   if (!same_type_p (type, lfi->type) 
       && template_self_reference_p (type, nval))
-    return NULL_TREE;
+    goto done;
 
   /* If the lookup already found a match, and the new value doesn't
      hide the old one, we might have an ambiguity.  */
@@ -1165,6 +1152,10 @@ lookup_field_r (tree binfo, void *data)
       lfi->rval_binfo = binfo;
     }
 
+ done:
+  /* Don't look for constructors or destructors in base classes.  */
+  if (IDENTIFIER_CTOR_OR_DTOR_P (lfi->name))
+    return dfs_skip_bases;
   return NULL_TREE;
 }
 
@@ -1251,8 +1242,7 @@ lookup_member (tree xbasetype, tree name, int protect, bool want_type)
   lfi.type = type;
   lfi.name = name;
   lfi.want_type = want_type;
-  dfs_walk_real (basetype_path, &lookup_field_r, 0,
-		 &lookup_field_queue_p, &lfi);
+  dfs_walk_all (basetype_path, &lookup_field_r, NULL, &lfi);
   rval = lfi.rval;
   rval_binfo = lfi.rval_binfo;
   if (rval_binfo)
@@ -1464,6 +1454,22 @@ lookup_fnfields_1 (tree type, tree name)
   return -1;
 }
 
+/* Like lookup_fnfields_1, except that the name is extracted from
+   FUNCTION, which is a FUNCTION_DECL or a TEMPLATE_DECL.  */
+
+int
+class_method_index_for_fn (tree class_type, tree function)
+{
+  gcc_assert (TREE_CODE (function) == FUNCTION_DECL
+	      || DECL_FUNCTION_TEMPLATE_P (function));
+
+  return lookup_fnfields_1 (class_type,
+			    DECL_CONSTRUCTOR_P (function) ? ctor_identifier :
+			    DECL_DESTRUCTOR_P (function) ? dtor_identifier :
+			    DECL_NAME (function));
+}
+
+
 /* DECL is the result of a qualified name lookup.  QUALIFYING_SCOPE is
    the class or namespace used to qualify the name.  CONTEXT_CLASS is
    the class corresponding to the object in which DECL will be used.
@@ -1510,66 +1516,158 @@ adjust_result_of_qualified_name_lookup (tree decl,
 
 
 /* Walk the class hierarchy within BINFO, in a depth-first traversal.
-   PREFN is called in preorder, while POSTFN is called in postorder.
-   If they ever returns a non-NULL value, that value is immediately
-   returned and the walk is terminated.  Both PREFN and POSTFN can be
-   NULL.  At each node, PREFN and POSTFN are passed the binfo to
-   examine.  Before each base-binfo of BINFO is walked, QFN is called.
-   If the value returned is nonzero, the base-binfo is walked;
-   otherwise it is not.  If QFN is NULL, it is treated as a function
-   which always returns 1.  All callbacks are passed DATA whenever
-   they are called.  */
+   PRE_FN is called in preorder, while POST_FN is called in postorder.
+   If PRE_FN returns DFS_SKIP_BASES, child binfos will not be
+   walked.  If PRE_FN or POST_FN returns a different non-NULL value,
+   that value is immediately returned and the walk is terminated.  One
+   of PRE_FN and POST_FN can be NULL.  At each node, PRE_FN and
+   POST_FN are passed the binfo to examine and the caller's DATA
+   value.  All paths are walked, thus virtual and morally virtual
+   binfos can be multiply walked.  */
 
 tree
-dfs_walk_real (tree binfo,
-	       tree (*prefn) (tree, void *),
-	       tree (*postfn) (tree, void *),
-	       tree (*qfn) (tree, int, void *),
-	       void *data)
+dfs_walk_all (tree binfo, tree (*pre_fn) (tree, void *),
+	      tree (*post_fn) (tree, void *), void *data)
 {
-  int i;
+  tree rval;
+  unsigned ix;
   tree base_binfo;
-  tree rval = NULL_TREE;
-
+  
   /* Call the pre-order walking function.  */
-  if (prefn)
+  if (pre_fn)
     {
-      rval = (*prefn) (binfo, data);
+      rval = pre_fn (binfo, data);
+      if (rval)
+	{
+	  if (rval == dfs_skip_bases)
+	    goto skip_bases;
+	  return rval;
+	}
+    }
+
+  /* Find the next child binfo to walk.  */
+  for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
+    {
+      rval = dfs_walk_all (base_binfo, pre_fn, post_fn, data);
       if (rval)
 	return rval;
     }
 
-  /* Process the basetypes.  */
-  for (i = 0; BINFO_BASE_ITERATE (binfo, i, base_binfo); i++)
+ skip_bases:
+  /* Call the post-order walking function.  */
+  if (post_fn)
+    return post_fn (binfo, data);
+  return NULL_TREE;
+}
+
+/* Worker for dfs_walk_once.  This behaves as dfs_walk_all, except
+   that binfos are walked at most once.  */
+
+static tree
+dfs_walk_once_r (tree binfo, tree (*pre_fn) (tree, void *),
+		 tree (*post_fn) (tree, void *), void *data)
+{
+  tree rval;
+  unsigned ix;
+  tree base_binfo;
+  
+  /* Call the pre-order walking function.  */
+  if (pre_fn)
     {
-      if (qfn)
+      rval = pre_fn (binfo, data);
+      if (rval)
 	{
-	  base_binfo = (*qfn) (binfo, i, data);
-	  if (!base_binfo)
+	  if (rval == dfs_skip_bases)
+	    goto skip_bases;
+	  
+	  return rval;
+	}
+    }
+
+  /* Find the next child binfo to walk.  */
+  for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
+    {
+      if (BINFO_VIRTUAL_P (base_binfo))
+	{
+	  if (BINFO_MARKED (base_binfo))
 	    continue;
+	  BINFO_MARKED (base_binfo) = 1;
 	}
-      rval = dfs_walk_real (base_binfo, prefn, postfn, qfn, data);
+  
+      rval = dfs_walk_once_r (base_binfo, pre_fn, post_fn, data);
       if (rval)
 	return rval;
     }
-
+  
+ skip_bases:
   /* Call the post-order walking function.  */
-  if (postfn)
-    rval = (*postfn) (binfo, data);
+  if (post_fn)
+    return post_fn (binfo, data);
   
-  return rval;
+  return NULL_TREE;
+}
+
+/* Worker for dfs_walk_once. Recursively unmark the virtual base binfos of
+   BINFO.  */
+   
+static void
+dfs_unmark_r (tree binfo)
+{
+  unsigned ix;
+  tree base_binfo;
+  
+  /* Process the basetypes.  */
+  for (ix = 0; BINFO_BASE_ITERATE (binfo, ix, base_binfo); ix++)
+    {
+      if (BINFO_VIRTUAL_P (base_binfo))
+	{
+	  if (!BINFO_MARKED (base_binfo))
+	    continue;
+	  BINFO_MARKED (base_binfo) = 0;
+	}
+      /* Only walk, if it can contain more virtual bases.  */
+      if (CLASSTYPE_VBASECLASSES (BINFO_TYPE (base_binfo)))
+	dfs_unmark_r (base_binfo);
+    }
 }
 
-/* Exactly like dfs_walk_real, except that there is no pre-order
-   function call and  FN is called in post-order.  */
+/* Like dfs_walk_all, except that binfos are not multiply walked.  For
+   non-diamond shaped hierarchies this is the same as dfs_walk_all.
+   For diamond shaped hierarchies we must mark the virtual bases, to
+   avoid multiple walks.  */
 
 tree
-dfs_walk (tree binfo,
-	  tree (*fn) (tree, void *),
-	  tree (*qfn) (tree, int, void *),
-	  void *data)
+dfs_walk_once (tree binfo, tree (*pre_fn) (tree, void *),
+	       tree (*post_fn) (tree, void *), void *data)
 {
-  return dfs_walk_real (binfo, 0, fn, qfn, data);
+  tree rval;
+
+  gcc_assert (pre_fn || post_fn);
+  
+  if (!CLASSTYPE_DIAMOND_SHAPED_P (BINFO_TYPE (binfo)))
+    /* We are not diamond shaped, and therefore cannot encounter the
+       same binfo twice.  */
+    rval = dfs_walk_all (binfo, pre_fn, post_fn, data);
+  else
+    {
+      rval = dfs_walk_once_r (binfo, pre_fn, post_fn, data);
+      if (!BINFO_INHERITANCE_CHAIN (binfo))
+	{
+	  /* We are at the top of the hierarchy, and can use the
+             CLASSTYPE_VBASECLASSES list for unmarking the virtual
+             bases.  */
+	  VEC (tree) *vbases;
+	  unsigned ix;
+	  tree base_binfo;
+	  
+	  for (vbases = CLASSTYPE_VBASECLASSES (BINFO_TYPE (binfo)), ix = 0;
+	       VEC_iterate (tree, vbases, ix, base_binfo); ix++)
+	    BINFO_MARKED (base_binfo) = 0;
+	}
+      else
+	dfs_unmark_r (binfo);
+    }
+  return rval;
 }
 
 /* Check that virtual overrider OVERRIDER is acceptable for base function
@@ -1789,8 +1887,6 @@ dfs_get_pure_virtuals (tree binfo, void *data)
 	  VEC_safe_push (tree, CLASSTYPE_PURE_VIRTUALS (type),
 			 BV_FN (virtuals));
     }
-  
-  BINFO_MARKED (binfo) = 1;
 
   return NULL_TREE;
 }
@@ -1809,40 +1905,9 @@ get_pure_virtuals (tree type)
      (A primary base is not interesting because the derived class of
      which it is a primary base will contain vtable entries for the
      pure virtuals in the base class.  */
-  dfs_walk (TYPE_BINFO (type), dfs_get_pure_virtuals, unmarkedp, type);
-  dfs_walk (TYPE_BINFO (type), dfs_unmark, markedp, type);
+  dfs_walk_once (TYPE_BINFO (type), NULL, dfs_get_pure_virtuals, type);
 }
 
-/* DEPTH-FIRST SEARCH ROUTINES.  */
-
-tree 
-markedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED) 
-{
-  tree binfo = BINFO_BASE_BINFO (derived, ix);
-  
-  return BINFO_MARKED (binfo) ? binfo : NULL_TREE; 
-}
-
-tree
-unmarkedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED) 
-{
-  tree binfo = BINFO_BASE_BINFO (derived, ix);
-  
-  return !BINFO_MARKED (binfo) ? binfo : NULL_TREE; 
-}
-
-/* The worker functions for `dfs_walk'.  These do not need to
-   test anything (vis a vis marking) if they are paired with
-   a predicate function (above).  */
-
-tree
-dfs_unmark (tree binfo, void *data ATTRIBUTE_UNUSED)
-{
-  BINFO_MARKED (binfo) = 0;
-  return NULL_TREE;
-}
-
-
 /* Debug info for C++ classes can get very large; try to avoid
    emitting it everywhere.
 
@@ -1889,23 +1954,14 @@ dfs_debug_mark (tree binfo, void *data ATTRIBUTE_UNUSED)
 {
   tree t = BINFO_TYPE (binfo);
 
+  if (CLASSTYPE_DEBUG_REQUESTED (t))
+    return dfs_skip_bases;
+
   CLASSTYPE_DEBUG_REQUESTED (t) = 1;
 
   return NULL_TREE;
 }
 
-/* Returns BINFO if we haven't already noted that we want debugging
-   info for this base class.  */
-
-static tree 
-dfs_debug_unmarkedp (tree derived, int ix, void *data ATTRIBUTE_UNUSED)
-{
-  tree binfo = BINFO_BASE_BINFO (derived, ix);
-  
-  return (!CLASSTYPE_DEBUG_REQUESTED (BINFO_TYPE (binfo)) 
-	  ? binfo : NULL_TREE);
-}
-
 /* Write out the debugging information for TYPE, whose vtable is being
    emitted.  Also walk through our bases and note that we want to
    write out information for them.  This avoids the problem of not
@@ -1922,7 +1978,7 @@ note_debug_info_needed (tree type)
       rest_of_type_compilation (type, toplevel_bindings_p ());
     }
 
-  dfs_walk (TYPE_BINFO (type), dfs_debug_mark, dfs_debug_unmarkedp, 0);
+  dfs_walk_all (TYPE_BINFO (type), dfs_debug_mark, NULL, 0);
 }
 
 void