re PR c++/23984 (second operand of PLUS_EXPR is NULL (in constructor))

cp:
	PR c++/23984
	* class.c (build_base_path): The vtable is always the first thing
	in the vtt.
testsuite:
	PR c++/23984
	* g++.dg/init/ctor7.C: New.

From-SVN: r105396

gcc/cp/ChangeLog

+2005-10-13  Nathan Sidwell  <nathan@codesourcery.com>
+
+	PR c++/23984
+	* class.c (build_base_path): The vtable is always the first thing
+	in the vtt.
+
 2005-10-13  Mark Mitchell  <mark@codesourcery.com>
 
 	PR c++/20721

gcc/cp/class.c

@@ -325,16 +325,14 @@ build_base_path (enum tree_code code,
 
       if (fixed_type_p < 0 && in_base_initializer)
 	{
-	  /* In a base member initializer, we cannot rely on
-	     the vtable being set up. We have to use the vtt_parm.  */
-	  tree derived = BINFO_INHERITANCE_CHAIN (v_binfo);
+	  /* In a base member initializer, we cannot rely on the
+	     vtable being set up.  We have to indirect via the
+	     vtt_parm.  */
 	  tree t;
 
-	  t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
+	  t = TREE_TYPE (TYPE_VFIELD (current_class_type));
 	  t = build_pointer_type (t);
 	  v_offset = convert (t, current_vtt_parm);
-	  v_offset = build2 (PLUS_EXPR, t, v_offset,
-			     BINFO_VPTR_INDEX (derived));
 	  v_offset = build_indirect_ref (v_offset, NULL);
 	}
       else

gcc/testsuite/ChangeLog

+2005-10-14  Nathan Sidwell  <nathan@codesourcery.com>
+
+	PR c++/23984
+	* g++.dg/init/ctor7.C: New.
+
 2005-10-13  David Edelsohn  <edelsohn@gnu.org>
 
 	PR c++/23730

gcc/testsuite/g++.dg/init/ctor7.C

+// { dg-do run }
+
+// Copyright (C) 2005 Free Software Foundation, Inc.
+// Contributed by Nathan Sidwell 13 Oct 2005 <nathan@codesourcery.com>
+
+// PR 23984:ICE
+// Origin:  Andrew Pinski pinskia@gcc.gnu.org
+
+struct B
+{
+  virtual void Foo ();
+};
+
+void B::Foo ()
+{
+}
+
+struct D : virtual B
+{
+};
+
+struct E
+{
+  B *ptr;
+  
+  E (B *);
+};
+
+static B *ptr;
+
+E::E (B *ptr_)
+  :ptr (ptr_)
+{
+}
+
+struct G : D, E
+{
+  G ();
+};
+
+G::G ()
+  : E (this)
+{
+}
+
+int main ()
+{
+  G object;
+
+  return object.ptr != &object;
+}