gcc 3.0 internal compiler error at varasm.c:591

[Robert McNulty Junior]

  /* Check that we are not being given an automatic variable.  */
  /* A weak alias has TREE_PUBLIC set but not the other bits.  */
  if (TREE_CODE (decl) == PARM_DECL
      || TREE_CODE (decl) == RESULT_DECL
      || (TREE_CODE (decl) == VAR_DECL
	  && !TREE_STATIC (decl)
	  && !TREE_PUBLIC (decl)
	  && !DECL_EXTERNAL (decl)
	  && !DECL_REGISTER (decl)))
    abort ();

What caused the abortion?