cp-tree.h (CLASSTYPE_VFIELD_PARENT): Update comments.

1999-12-20  Mark Mitchell  <mark@codesourcery.com>

	* cp-tree.h (CLASSTYPE_VFIELD_PARENT): Update comments.
	(CLASSTYPE_HAS_PRIMARY_BASE_P): New macro.
	(CLASSTYPE_PRIMARY_BINFO): Likewise.
	* class.c (check_methods): Don't set TYPE_HAS_COMPLEX_INIT_REF,
	TYPE_NEEDS_CONSTRUCTING, and CLASSTYPE_NON_AGGREGATE here.
	(check_bases_and_members): Set them here instead.
	(create_vtable_ptr): New function, split out from ...
	(finish_struct_1): ... here.  Use it.  Tidy.  Use
	CLASSTYPE_HAS_PRIMARY_BASE_P and CLASSTYPE_PRIMARY_BINFO.
	* search.c (dfs_init_vbase_pointers): Handle seeing TYPE_VFIELD as
	the first field in the class.
	* tree.c (layout_basetypes): Use CLASSTYPE_N_BASECLASSES.  Handle
	seeing TYPE_VFIELD as the first field in the class.

From-SVN: r31042

gcc/cp/ChangeLog

 1999-12-20  Mark Mitchell  <mark@codesourcery.com>
 
+	* cp-tree.h (CLASSTYPE_VFIELD_PARENT): Update comments.
+	(CLASSTYPE_HAS_PRIMARY_BASE_P): New macro.
+	(CLASSTYPE_PRIMARY_BINFO): Likewise.
+	* class.c (check_methods): Don't set TYPE_HAS_COMPLEX_INIT_REF,
+	TYPE_NEEDS_CONSTRUCTING, and CLASSTYPE_NON_AGGREGATE here.
+	(check_bases_and_members): Set them here instead.
+	(create_vtable_ptr): New function, split out from ...
+	(finish_struct_1): ... here.  Use it.  Tidy.  Use
+	CLASSTYPE_HAS_PRIMARY_BASE_P and CLASSTYPE_PRIMARY_BINFO.
+	* search.c (dfs_init_vbase_pointers): Handle seeing TYPE_VFIELD as
+	the first field in the class.
+	* tree.c (layout_basetypes): Use CLASSTYPE_N_BASECLASSES.  Handle
+	seeing TYPE_VFIELD as the first field in the class.
+	
 	* cp-tree.h (TYPE_VIRTUAL_P): Rename to ...
 	(TYPE_POLYMORPHIC_P): ... this.
 	(TYPE_USES_COMPLEX_INHERITANCE): Rename to ...

gcc/cp/cp-tree.h

@@ -1382,13 +1382,26 @@ struct lang_type
    nested member class templates.  */
 #define CLASSTYPE_TAGS(NODE)		(TYPE_LANG_SPECIFIC(NODE)->tags)
 
-/* If this class has any bases, this is the number of the base class from
-   which our VFIELD is based, -1 otherwise.  If this class has no base
-   classes, this is not used.
-   In D : B1, B2, PARENT would be 0, if D's vtable came from B1,
-   1, if D's vtable came from B2.  */
+/* If this value is non-negative, it is the index (in the
+   TYPE_BINFO_BASETYPES) for the base-class whose vtable pointer we
+   are reusing.  For example, in D : B1, B2, PARENT would be 0, if D's
+   vtable came from B1, 1, if D's vtable came from B2.  */
 #define CLASSTYPE_VFIELD_PARENT(NODE)	(TYPE_LANG_SPECIFIC(NODE)->vfield_parent)
 
+/* Nonzero if NODE has a primary base class, i.e., a base class with
+   which it shares the virtual fucntion table pointer.  */
+#define CLASSTYPE_HAS_PRIMARY_BASE_P(NODE) \
+  (CLASSTYPE_VFIELD_PARENT (NODE) != -1)
+
+/* If non-NULL, this is the binfo for the primary base class, i.e.,
+   the base class which contains the virtual function table pointer
+   for this class.  */
+#define CLASSTYPE_PRIMARY_BINFO(NODE) 			\
+  (CLASSTYPE_HAS_PRIMARY_BASE_P (NODE)			\
+   ? TREE_VEC_ELT (TYPE_BINFO_BASETYPES (NODE),		\
+		   CLASSTYPE_VFIELD_PARENT (NODE))	\
+   : NULL_TREE)
+
 /* The number of virtual functions defined for this
    _CLASSTYPE node.  */
 #define CLASSTYPE_VSIZE(NODE) (TYPE_LANG_SPECIFIC(NODE)->vsize)

gcc/cp/search.c

@@ -2432,18 +2432,11 @@ dfs_init_vbase_pointers (binfo, data)
 {
   struct vbase_info *vi = (struct vbase_info *) data;
   tree type = BINFO_TYPE (binfo);
-  tree fields = TYPE_FIELDS (type);
+  tree fields;
   tree this_vbase_ptr;
 
   CLEAR_BINFO_VTABLE_PATH_MARKED (binfo);
 
-#if 0
-  /* See finish_struct_1 for when we can enable this.  */
-  /* If we have a vtable pointer first, skip it.  */
-  if (VFIELD_NAME_P (DECL_NAME (fields)))
-    fields = TREE_CHAIN (fields);
-#endif
-
   if (BINFO_INHERITANCE_CHAIN (binfo))
     {
       this_vbase_ptr = TREE_CHAIN (BINFO_INHERITANCE_CHAIN (binfo));
@@ -2457,6 +2450,14 @@ dfs_init_vbase_pointers (binfo, data)
   else
     this_vbase_ptr = TREE_CHAIN (binfo);
 
+  /* We're going to iterate through all the pointers to virtual
+     base-classes.  They come at the beginning of the class.  */
+  fields = TYPE_FIELDS (type);
+  if (fields == TYPE_VFIELD (type))
+    /* If the first field is the vtbl pointer (as happens in the new
+       ABI), skip it.  */
+    fields = TREE_CHAIN (fields);
+
   if (fields == NULL_TREE
       || DECL_NAME (fields) == NULL_TREE
       || ! VBASE_NAME_P (DECL_NAME (fields)))

gcc/cp/tree.c

@@ -693,15 +693,7 @@ propagate_binfo_offsets (binfo, offset)
 		break;
 	      }
 
-#if 0
-	  if (BINFO_OFFSET_ZEROP (base_binfo))
-	    BINFO_OFFSET (base_binfo) = offset;
-	  else
-	    BINFO_OFFSET (base_binfo)
-	      = size_binop (PLUS_EXPR, BINFO_OFFSET (base_binfo), offset);
-#else
 	  BINFO_OFFSET (base_binfo) = offset;
-#endif
 
 	  propagate_binfo_offsets (base_binfo, offset);
 
@@ -759,9 +751,9 @@ layout_basetypes (rec, max)
      int max;
 {
   tree binfos = TYPE_BINFO_BASETYPES (rec);
-  int i, n_baseclasses = binfos ? TREE_VEC_LENGTH (binfos) : 0;
-
+  int i, n_baseclasses = CLASSTYPE_N_BASECLASSES (rec);
   tree vbase_types;
+  tree *field;
 
   unsigned int record_align = MAX (BITS_PER_UNIT, TYPE_ALIGN (rec));
   unsigned int desired_align;
@@ -835,27 +827,43 @@ layout_basetypes (rec, max)
                                          size_int (BITS_PER_UNIT));
     }
 
-  /* Now propagate offset information throughout the lattice.  */
+  /* Now propagate offset information throughout the lattice.
+     Simultaneously, remove the temporary FIELD_DECLS we created in
+     build_base_fields to refer to base types.  */
+  field = &TYPE_FIELDS (rec);
+  if (TYPE_VFIELD (rec) == *field)
+    {
+      /* If this class did not have a primary base, we create a
+	 virtual function table pointer.  It will be the first thing
+	 in the class, under the new ABI.  Skip it; the base fields
+	 will follow it.  */
+      my_friendly_assert (flag_new_abi 
+			  && !CLASSTYPE_HAS_PRIMARY_BASE_P (rec),
+			  19991218);
+      field = &TREE_CHAIN (*field);
+    }
+    
   for (i = 0; i < n_baseclasses; i++)
     {
       register tree base_binfo = TREE_VEC_ELT (binfos, i);
       register tree basetype = BINFO_TYPE (base_binfo);
-      tree field = TYPE_FIELDS (rec);
 
       if (TREE_VIA_VIRTUAL (base_binfo))
 	continue;
 
-      my_friendly_assert (TREE_TYPE (field) == basetype, 23897);
+      my_friendly_assert (TREE_TYPE (*field) == basetype, 23897);
 
       if (get_base_distance (basetype, rec, 0, (tree*)0) == -2)
 	cp_warning ("direct base `%T' inaccessible in `%T' due to ambiguity",
 		    basetype, rec);
 
       BINFO_OFFSET (base_binfo)
-	= size_int (CEIL (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (field)),
+	= size_int (CEIL (TREE_INT_CST_LOW (DECL_FIELD_BITPOS (*field)),
 			  BITS_PER_UNIT));
       propagate_binfo_offsets (base_binfo, BINFO_OFFSET (base_binfo));
-      TYPE_FIELDS (rec) = TREE_CHAIN (field);
+
+      /* Remove this field.  */
+      *field = TREE_CHAIN (*field);
     }
 
   for (vbase_types = CLASSTYPE_VBASECLASSES (rec); vbase_types;