用于进行gcc测试

				/* { dg-do run } */				// { dg-additional-sources "nested-extern.cc" }				/* PR 31775 */				extern "C" void abort();				static int i;				int *p = &i;				int main()				{ 				  int i;				  { 				    extern int i;				    i = 1;				    *p = 2;				    if (i == 2)				      abort ();				  }				  return 0;				}