[C++ PATCH]: Fix 23984

[Nathan Sidwell <nathan at codesourcery dot com>]

I've installed this patch to fix 23984.  The vtable we want is always the first 
one in the vtt parm.  No need to add the VPTR_IDX, which might be completely bogus.

built & checked on i686-pc-linux-gnu.

nathan
--
Nathan Sidwell    ::   http://www.codesourcery.com   ::     CodeSourcery LLC
nathan@codesourcery.com    ::     http://www.planetfall.pwp.blueyonder.co.uk

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.

Index: cp/class.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cp/class.c,v
retrieving revision 1.735
diff -c -3 -p -r1.735 class.c
*** cp/class.c	12 Oct 2005 20:54:49 -0000	1.735
--- cp/class.c	14 Oct 2005 08:28:27 -0000
*************** build_base_path (enum tree_code code,
*** 325,340 ****
  
        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);
  	  tree t;
  
! 	  t = TREE_TYPE (TYPE_VFIELD (BINFO_TYPE (derived)));
  	  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
--- 325,338 ----
  
        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 indirect via the
! 	     vtt_parm.  */
  	  tree t;
  
! 	  t = TREE_TYPE (TYPE_VFIELD (current_class_type));
  	  t = build_pointer_type (t);
  	  v_offset = convert (t, current_vtt_parm);
  	  v_offset = build_indirect_ref (v_offset, NULL);
  	}
        else

// { 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;
}