def get_var_names(var_name):
  """Defines replacement dictionary for the bare variable name and
     the names derived from it - the optimization flag and the identifier name.
  """
  repl = dict()
  repl['opt_var_name'] = "Opt_%s"%var_name
  repl['id_var_name'] = "ID_%s"%var_name
  repl['var_name'] = var_name
  return repl