Subversion Repositories openrisc

// Copyright (C) 2005 Free Software Foundation, Inc.

// Contributed by Nathan Sidwell 4 Apr 2005 

// { dg-do run }

// PR 20746: Covariant return pointer could be null.

// Origin: yanliu@ca.ibm.com

//         nathan@codesourcery.com

struct A {

  virtual void One ();

};

struct B  {

  virtual B *Two ();

  virtual B &Three ();

};

struct C : A, B

{

  virtual C *Two ();

  virtual C &Three ();

};

void A::One () {}

B *B::Two()    {return this;}

B &B::Three()    {return *this;}

C *C::Two ()   {return 0;}

C &C::Three ()   {return *(C *)0;}

B *Foo (B *b)

{

  return b->Two ();

}

B &Bar (B *b)

{

  return b->Three ();

}

int main ()

{

  C c;

  /* We should not adjust a null pointer.  */

  if (Foo (&c))

    return 1;

  /* But we should adjust a (bogus) null reference.  */

  if (!&Bar (&c))

    return 2;

  return 0;

}