rem: Dirstack_state *ds = XMALLOC (struct dirstack_state, 1);
add: Dirstack_state *ds = xmalloc (sizeof *ds);
context: ds_init (){  Dirstack_state *ds = XMALLOC (struct dirstack_state, 1);  obstack_init (&ds->dir_stack);  obstack_init (&ds->len_stack);  obstack_init (&ds->Active_dir);  return ds;}