Put RTTI entries at negative offsets in new ABI.

	* class.c (dfs_build_vbase_offset_vtbl_entries): Put the first
	vbase offset at index -3, not -1.
	(build_vtabe_offset_vtbl_entries): Use unmarked_vtable_pathp, not
	dfs_vtable_path_unmarked_real_bases_queue_p to walk bases.
	(dfs_build_vcall_offset_vtbl_entries): Don't use skip_rtti_stuff.
	(build_rtti_vtbl_entries): New function.
	(set_rtti_entry): Remove.
	(build_primary_vtable): Don't use it.
	(build_secondary_vtable): Likewise.
	(start_vtable): Remove.
	(first_vfun_index): New function.
	(set_vindex): Likewise.
	(add_virtual_function): Don't call start_vtable.  Do call
	set_vindex.
	(set_primary_base): Rename parameter.
	(determine_primary_base): Likewise.
	(num_vfun_entries): Don't use skip_rtti_stuff.
	(num_extra_vtbl_entries): Include RTTI information.
	(build_vtbl_initializer): Use build_rtti_vtbl_entries.
	(skip_rtti_stuff): Remove.
	(dfs_modify_vtables): Don't use it.
	(modify_all_vtables): Don't use start_vtable.  Do use set_vindex.
	(layout_nonempty_base_or_field): Update size handling.
	(create_vtable_ptr): Tweak.
	(layout_class_type): Adjust parameter names.
	(finish_struct_1): Simplify.
	* cp-tree.h (CLASSTYPE_VSIZE): Tweak documentation.
	(skip_rtti_stuff): Remove.
	(first_vfun_index): New function.
	(dfs_vtable_path_unmarked_real_bases_queue_p): Remove.
	(dfs_vtable_path_marked_real_bases_queue_p): Remove.
	(marked_vtable_pathp): Declare.
	(unmarked_vtable_pathp): Likewise.
	* error.c (dump_expr): Use first_vfun_index to calculate vtable
	offsets.
	* rtti.c (build_headof): Look for RTTI at negative offsets.
	(get_tinfo_decl_dynamic): Likewise.
	(tinfo_base_init): Don't take the address of the TINFO_VTABLE_DECL
	here.
	(create_pseudo_type_info): Do it here instead.  Adjust so that
	vptr points at first virtual function.
	* search.c (marked_vtable_pathp): Make it global.
	(unmarked_vtable_pathp): Likewise.
	(dfs_vtable_path_unmarked_real_bases_queue_p): Remove.
	(dfs_vtable_path_marked_real_bases_queue_p): Likewise.
	(dfs_get_pure_virtuals): Don't use skip_rtti_stuff.
	(get_pure_virtuals): Likewise.
	(expand_upcast_fixups): Likewise.
	* tree.c (debug_binfo): Likewise.
	* tinfo.cc (__dynamic_cast): Look for vtable_prefix at appropriate
	negative offset.

From-SVN: r32787

gcc/cp/ChangeLog

+2000-03-28  Mark Mitchell  <mark@codesourcery.com>
+
+	Put RTTI entries at negative offsets in new ABI.
+	* class.c (dfs_build_vbase_offset_vtbl_entries): Put the first
+	vbase offset at index -3, not -1.
+	(build_vtabe_offset_vtbl_entries): Use unmarked_vtable_pathp, not
+	dfs_vtable_path_unmarked_real_bases_queue_p to walk bases.
+	(dfs_build_vcall_offset_vtbl_entries): Don't use skip_rtti_stuff.
+	(build_rtti_vtbl_entries): New function.
+	(set_rtti_entry): Remove.
+	(build_primary_vtable): Don't use it.
+	(build_secondary_vtable): Likewise.
+	(start_vtable): Remove.
+	(first_vfun_index): New function.
+	(set_vindex): Likewise.
+	(add_virtual_function): Don't call start_vtable.  Do call
+	set_vindex.
+	(set_primary_base): Rename parameter.
+	(determine_primary_base): Likewise.
+	(num_vfun_entries): Don't use skip_rtti_stuff.
+	(num_extra_vtbl_entries): Include RTTI information.
+	(build_vtbl_initializer): Use build_rtti_vtbl_entries.
+	(skip_rtti_stuff): Remove.
+	(dfs_modify_vtables): Don't use it.
+	(modify_all_vtables): Don't use start_vtable.  Do use set_vindex.
+	(layout_nonempty_base_or_field): Update size handling.
+	(create_vtable_ptr): Tweak.
+	(layout_class_type): Adjust parameter names.
+	(finish_struct_1): Simplify.
+	* cp-tree.h (CLASSTYPE_VSIZE): Tweak documentation.
+	(skip_rtti_stuff): Remove.
+	(first_vfun_index): New function.
+	(dfs_vtable_path_unmarked_real_bases_queue_p): Remove.
+	(dfs_vtable_path_marked_real_bases_queue_p): Remove.
+	(marked_vtable_pathp): Declare.
+	(unmarked_vtable_pathp): Likewise.
+	* error.c (dump_expr): Use first_vfun_index to calculate vtable
+	offsets.
+	* rtti.c (build_headof): Look for RTTI at negative offsets.
+	(get_tinfo_decl_dynamic): Likewise.
+	(tinfo_base_init): Don't take the address of the TINFO_VTABLE_DECL
+	here.
+	(create_pseudo_type_info): Do it here instead.  Adjust so that
+	vptr points at first virtual function.
+	* search.c (marked_vtable_pathp): Make it global.
+	(unmarked_vtable_pathp): Likewise.
+	(dfs_vtable_path_unmarked_real_bases_queue_p): Remove.
+	(dfs_vtable_path_marked_real_bases_queue_p): Likewise.
+	(dfs_get_pure_virtuals): Don't use skip_rtti_stuff.
+	(get_pure_virtuals): Likewise.
+	(expand_upcast_fixups): Likewise.
+	* tree.c (debug_binfo): Likewise.
+	* tinfo.cc (__dynamic_cast): Look for vtable_prefix at appropriate
+	negative offset.
+	
 Sun Mar 26 20:15:26 2000  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>
 
 	* class.c (check_field_decl): Fix typo.

gcc/cp/cp-tree.h

@@ -1545,8 +1545,8 @@ struct lang_type
 		     CLASSTYPE_VFIELD_PARENT (BINFO_TYPE (NODE)))	\
    : NULL_TREE)
 
-/* The number of virtual functions defined for this
-   _CLASSTYPE node.  */
+/* The number of virtual functions present in this classes virtual
+   function table.  */
 #define CLASSTYPE_VSIZE(NODE) (TYPE_LANG_SPECIFIC(NODE)->vsize)
 
 /* A chain of BINFOs for the direct and indirect virtual base classes
@@ -3685,8 +3685,7 @@ extern void push_lang_context			PARAMS ((tree));
 extern void pop_lang_context			PARAMS ((void));
 extern tree instantiate_type			PARAMS ((tree, tree, int));
 extern void print_class_statistics		PARAMS ((void));
-extern tree skip_rtti_stuff	                PARAMS ((tree, tree,
-							 HOST_WIDE_INT *));
+extern int first_vfun_index                     PARAMS ((tree));
 extern void build_self_reference		PARAMS ((void));
 extern void warn_hidden				PARAMS ((tree));
 extern tree get_enclosing_class			PARAMS ((tree));
@@ -4212,11 +4211,9 @@ extern tree dfs_skip_nonprimary_vbases_unmarkedp PARAMS ((tree, void *));
 extern tree dfs_skip_nonprimary_vbases_markedp  PARAMS ((tree, void *));
 extern tree dfs_unmarked_real_bases_queue_p     PARAMS ((tree, void *));
 extern tree dfs_marked_real_bases_queue_p       PARAMS ((tree, void *));
-extern tree dfs_vtable_path_unmarked_real_bases_queue_p
-                                                PARAMS ((tree, void *));
-extern tree dfs_vtable_path_marked_real_bases_queue_p
-                                                PARAMS ((tree, void *));
 extern tree dfs_skip_vbases                     PARAMS ((tree, void *));
+extern tree marked_vtable_pathp                 PARAMS ((tree, void *));
+extern tree unmarked_vtable_pathp               PARAMS ((tree, void *));
 extern void mark_primary_bases                  PARAMS ((tree));
 extern tree convert_pointer_to_vbase            PARAMS ((tree, tree));
 extern tree find_vbase_instance                 PARAMS ((tree, tree));

gcc/cp/error.c

@@ -1857,7 +1857,7 @@ dump_expr (t, flags)
 	      t = TYPE_METHOD_BASETYPE (t);
 	      virtuals = TYPE_BINFO_VIRTUALS (TYPE_MAIN_VARIANT (t));
 	      
-	      n = tree_low_cst (idx, 0);
+	      n = tree_low_cst (idx, 0) - first_vfun_index (t);
 
 	      /* Map vtable index back one, to allow for the null pointer to
 		 member.  */

gcc/cp/rtti.c

@@ -132,6 +132,7 @@ build_headof (exp)
   tree type = TREE_TYPE (exp);
   tree aref;
   tree offset;
+  tree index;
 
   my_friendly_assert (TREE_CODE (type) == POINTER_TYPE, 20000112);
   type = TREE_TYPE (type);
@@ -151,7 +152,15 @@ build_headof (exp)
   /* We use this a couple of times below, protect it.  */
   exp = save_expr (exp);
 
-  aref = build_vtbl_ref (build_indirect_ref (exp, NULL_PTR), integer_zero_node);
+  /* Under the new ABI, the offset-to-top field is at index -2 from
+     the vptr.  */
+  if (new_abi_rtti_p ())
+    index = build_int_2 (-2, -1);
+  /* But under the old ABI, it is at offset zero.  */
+  else
+    index = integer_zero_node;
+
+  aref = build_vtbl_ref (build_indirect_ref (exp, NULL_PTR), index);
 
   if (flag_vtable_thunks)
     offset = aref;
@@ -230,6 +239,7 @@ get_tinfo_decl_dynamic (exp)
     {
       /* build reference to type_info from vtable.  */
       tree t;
+      tree index;
 
       if (! flag_rtti)
 	error ("taking dynamic typeid of object with -fno-rtti");
@@ -247,10 +257,15 @@ get_tinfo_decl_dynamic (exp)
 	  exp = build_indirect_ref (exp, NULL_PTR);
 	}
 
-      if (flag_vtable_thunks)
-	t = build_vfn_ref ((tree *) 0, exp, integer_one_node);
+      /* The RTTI information is always in the vtable, but it's at
+	 different indices depending on the ABI.  */
+      if (new_abi_rtti_p ())
+	index = minus_one_node;
+      else if (flag_vtable_thunks)
+	index = integer_one_node;
       else
-	t = build_vfn_ref ((tree *) 0, exp, integer_zero_node);
+	index = integer_zero_node;
+      t = build_vfn_ref ((tree *) 0, exp, index);
       TREE_TYPE (t) = build_pointer_type (tinfo_decl_type);
       return t;
     }
@@ -1284,8 +1299,7 @@ tinfo_base_init (desc, target)
   
   if (TINFO_VTABLE_DECL (desc))
     {
-      tree vtbl_ptr = build_unary_op (ADDR_EXPR, TINFO_VTABLE_DECL (desc), 0);
-  
+      tree vtbl_ptr = TINFO_VTABLE_DECL (desc);
       init = tree_cons (NULL_TREE, vtbl_ptr, init);
     }
   
@@ -1616,7 +1630,18 @@ create_pseudo_type_info VPARAMS((const char *real_name, int ident, ...))
   /* Get the vtable decl. */
   real_type = xref_tag (class_type_node, get_identifier (real_name), 1);
   vtable_decl = get_vtable_decl (real_type, /*complete=*/1);
-  
+  vtable_decl = build_unary_op (ADDR_EXPR, vtable_decl, 0);
+
+  /* Under the new ABI, we need to point into the middle of the
+     vtable.  */
+  if (vbase_offsets_in_vtable_p ())
+    {
+      vtable_decl = build (PLUS_EXPR, TREE_TYPE (vtable_decl), 
+			   vtable_decl,
+			   size_extra_vtbl_entries (TYPE_BINFO (real_type)));
+      TREE_CONSTANT (vtable_decl) = 1;
+    }
+
   /* First field is the pseudo type_info base class. */
   fields[0] = build_lang_decl (FIELD_DECL, NULL_TREE, ti_desc_type_node);
   

gcc/cp/search.c

@@ -104,8 +104,6 @@ static void expand_upcast_fixups
 static void fixup_virtual_upcast_offsets
 	PARAMS ((tree, tree, int, int, tree, tree, tree, tree,
 	       tree *));
-static tree marked_vtable_pathp PARAMS ((tree, void *));
-static tree unmarked_vtable_pathp PARAMS ((tree, void *));
 static tree marked_new_vtablep PARAMS ((tree, void *));
 static tree unmarked_new_vtablep PARAMS ((tree, void *));
 static tree marked_pushdecls_p PARAMS ((tree, void *));
@@ -2346,30 +2344,6 @@ dfs_marked_real_bases_queue_p (binfo, data)
   return binfo ? markedp (binfo, NULL) : NULL_TREE;
 }
 
-/* Like dfs_unmarked_real_bases_queue_p but walks only into things
-   that are not BINFO_VTABLE_PATH_MARKED.  */
-
-tree
-dfs_vtable_path_unmarked_real_bases_queue_p (binfo, data)
-     tree binfo;
-     void *data;
-{
-  binfo = get_shared_vbase_if_not_primary (binfo, data); 
-  return binfo ? unmarked_vtable_pathp (binfo, NULL): NULL_TREE;
-}
-
-/* Like dfs_unmarked_real_bases_queue_p but walks only into things
-   that are BINFO_VTABLE_PATH_MARKED.  */
-
-tree
-dfs_vtable_path_marked_real_bases_queue_p (binfo, data)
-     tree binfo;
-     void *data;
-{
-  binfo = get_shared_vbase_if_not_primary (binfo, data); 
-  return binfo ? marked_vtable_pathp (binfo, NULL): NULL_TREE;
-}
-
 /* A queue function that skips all virtual bases (and their 
    bases).  */
 
@@ -2400,9 +2374,7 @@ dfs_get_pure_virtuals (binfo, data)
     {
       tree virtuals;
       
-      for (virtuals = skip_rtti_stuff (binfo, 
-				       BINFO_TYPE (binfo), 
-				       NULL);
+      for (virtuals = BINFO_VIRTUALS (binfo);
 	   virtuals;
 	   virtuals = TREE_CHAIN (virtuals))
 	if (DECL_PURE_VIRTUAL_P (TREE_VALUE (virtuals)))
@@ -2447,7 +2419,7 @@ get_pure_virtuals (type)
     {
       tree virtuals;
 
-      for (virtuals = skip_rtti_stuff (vbases, BINFO_TYPE (vbases), NULL);
+      for (virtuals = BINFO_VIRTUALS (vbases);
 	   virtuals;
 	   virtuals = TREE_CHAIN (virtuals))
 	{
@@ -2527,7 +2499,7 @@ unmarkedp (binfo, data)
   return !BINFO_MARKED (binfo) ? binfo : NULL_TREE;
 }
 
-static tree
+tree
 marked_vtable_pathp (binfo, data) 
      tree binfo;
      void *data ATTRIBUTE_UNUSED;
@@ -2535,7 +2507,7 @@ marked_vtable_pathp (binfo, data)
   return BINFO_VTABLE_PATH_MARKED (binfo) ? binfo : NULL_TREE; 
 }
 
-static tree
+tree
 unmarked_vtable_pathp (binfo, data) 
      tree binfo;
      void *data ATTRIBUTE_UNUSED;
@@ -2863,9 +2835,10 @@ expand_upcast_fixups (binfo, addr, orig_addr, vbase, vbase_addr, t,
       *vbase_offsets = delta;
     }
 
-  virtuals = skip_rtti_stuff (binfo, BINFO_TYPE (binfo), &n);
-
-  while (virtuals)
+  for (virtuals = BINFO_VIRTUALS (binfo), 
+	 n = first_vfun_index (BINFO_TYPE (binfo));
+       virtuals;
+       virtuals = TREE_CHAIN (virtuals), ++n)
     {
       tree current_fndecl = TREE_VALUE (virtuals);
 
@@ -2956,8 +2929,6 @@ expand_upcast_fixups (binfo, addr, orig_addr, vbase, vbase_addr, t,
 	  finish_expr_stmt (build_modify_expr (new_delta, NOP_EXPR,
 					       old_delta));
 	}
-      ++n;
-      virtuals = TREE_CHAIN (virtuals);
     }
 }
 

gcc/cp/tinfo.cc

@@ -1100,9 +1100,8 @@ __dynamic_cast (const void *src_ptr,    // object started from
 {
   const void *vtable = *static_cast <const void *const *> (src_ptr);
   const vtable_prefix *prefix =
-      adjust_pointer <vtable_prefix> (vtable, 0);
-  // FIXME: the above offset should be -offsetof (vtable_prefix, origin));
-  // but we don't currently layout vtables correctly.
+      adjust_pointer <vtable_prefix> (vtable, 
+				      -offsetof (vtable_prefix, origin));
   const void *whole_ptr =
       adjust_pointer <void> (src_ptr, prefix->whole_object);
   const __class_type_info *whole_type = prefix->whole_type;

gcc/cp/tree.c

@@ -925,7 +925,8 @@ debug_binfo (elem)
   else
     fprintf (stderr, "no vtable decl yet\n");
   fprintf (stderr, "virtuals:\n");
-  virtuals = skip_rtti_stuff (elem, BINFO_TYPE (elem), &n);
+  virtuals = BINFO_VIRTUALS (elem);
+  n = first_vfun_index (BINFO_TYPE (elem));
 
   while (virtuals)
     {