[C++ PATCH] Fix bug 91

[Nathan Sidwell <nathan at codesourcery dot com>]

Hi,
I've installed this obvious patch for bug 91, were we were selecting
A::operator(A&) instead of A::operator(A const &) to assign the base
class in B::operator(B const &).

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

nathan
-- 
Dr Nathan Sidwell   ::   http://www.codesourcery.com   ::   CodeSourcery LLC
         'But that's a lie.' - 'Yes it is. What's your point?'
nathan@codesourcery.com : http://www.cs.bris.ac.uk/~nathan/ : nathan@acm.org
2000-11-30  Nathan Sidwell  <nathan@codesourcery.com>

	* method.c (do_build_assign_ref): Construct appropriately
	CV-qualified base reference. Don't allow const casts in base
	conversion.

Index: cp/method.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cp/method.c,v
retrieving revision 1.180
diff -c -3 -p -r1.180 method.c
*** method.c	2000/11/25 19:50:50	1.180
--- method.c	2000/11/30 09:02:51
*************** do_build_assign_ref (fndecl)
*** 2428,2436 ****
        for (i = 0; i < n_bases; ++i)
  	{
  	  tree basetype = BINFO_TYPE (TREE_VEC_ELT (binfos, i));
! 	  tree p = convert_to_reference
! 	    (build_reference_type (basetype), parm,
! 	     CONV_IMPLICIT|CONV_CONST, LOOKUP_COMPLAIN, NULL_TREE);
  	  p = convert_from_reference (p);
  	  p = build_member_call (basetype, ansi_assopname (NOP_EXPR),
  				 build_tree_list (NULL_TREE, p));
--- 2428,2439 ----
        for (i = 0; i < n_bases; ++i)
  	{
  	  tree basetype = BINFO_TYPE (TREE_VEC_ELT (binfos, i));
! 	  tree p = build_qualified_type
! 	      (basetype, CP_TYPE_QUALS (TREE_TYPE (parm)));
! 
! 	  p = convert_to_reference
! 	    (build_reference_type (p), parm,
! 	     CONV_IMPLICIT, LOOKUP_COMPLAIN, NULL_TREE);
  	  p = convert_from_reference (p);
  	  p = build_member_call (basetype, ansi_assopname (NOP_EXPR),
  				 build_tree_list (NULL_TREE, p));
// Copyright (C) 2000 Free Software Foundation, Inc.
// Contributed by Nathan Sidwell 28 Nov 2000 <nathan@codesourcery.com>

// Bug 91. We'd not preserve constness looking for a base classes assignment
// operator.

#include <stdio.h>

int glob = 0;

struct A
{
  A() {}

  A( A& arg) 
  { printf ("%s\n", __PRETTY_FUNCTION__); glob = 1;}

  A( const A& arg)
  { printf ("%s\n", __PRETTY_FUNCTION__); glob = 2;}

  A& operator=( A& ) 
  { printf ("%s\n", __PRETTY_FUNCTION__); glob = 3; return *this; }

  A& operator=( const A& ) 
  { printf ("%s\n", __PRETTY_FUNCTION__); glob = 4; return *this; }
};

struct B : A
{
  B () {}
};

void foo( A& )
{
  printf ("%s\n", __PRETTY_FUNCTION__); glob = 5;
}

void foo( const A& )
{
 printf ("%s\n", __PRETTY_FUNCTION__); glob = 6;
}


int main()
{
  const A a0;
  glob = 0; printf ("A(cA) : ");  A a1(a0); if (glob != 2) return 1;
  glob = 0; printf ("A(A ) : ");  A a2(a1); if (glob != 1) return 2;
  
  const B b0;
  glob = 0; printf ("B(cB) : ");  B b1(b0); if (glob != 2) return 3;
  glob = 0; printf ("B(B ) : ");  B b2(b1); if (glob != 2) return 4;

  glob = 0; printf ("A= cA : ");  a1 = a0; if (glob != 4) return 5;
  glob = 0; printf ("A= A : ");   a1 = a2; if (glob != 3) return 6;
  glob = 0; printf ("B= cB : ");  b1 = b0; if (glob != 4) return 7;
  glob = 0; printf ("B= B : ");   b1 = b2; if (glob != 4) return 8;

  glob = 0; printf ("foo(cB): "); foo(b0); if (glob != 6) return 9;
  glob = 0; printf ("foo(B ): "); foo(b2); if (glob != 5) return 10;

  return 0;
}