用于进行gcc测试

				// { dg-do compile }								// Copyright (C) 2002 Free Software Foundation, Inc.				// Contributed by Nathan Sidwell 16 Sep 2002 								// PR 7640. ICE.								void init ()				{				  do {  } while (0)					    obj = 0; // { dg-error "expected|not declared" "" }				     				}