用于进行gcc测试

				// PR target/29487				// { dg-do link }				// { dg-options "-O2" }								/* This function is not defined.  The compiler should optimize away				   all calls to it.  */				extern void undefined () throw ();								extern void f1();								inline void f2() {				  f1();				}								/* This function will be COMDAT if not inlined.  */				inline void f1() {}								/* This function will be COMDAT.  */				template 				void f3() {				  if (false)				    throw 3;				}								inline void f4() {				  if (false)				    throw 7;				}								int main () {				  try {				    f1();				    f2();				    f3();				    f4();				  } catch (...) {				    /* The compiler should recognize that none of the functions above				       can throw exceptions, and therefore remove this code as				       unreachable.  */				    undefined ();				  }				}