gcc/testsuite/g++.dg/torture/pushpop_macro.C

/* Do the preprocessor push_macro/pop_macro test.  */

/* { dg-do run } */

extern "C" void abort ();

#define _ 2
#pragma push_macro("_")
#undef _
#define _ 1
#pragma pop_macro("_")

int main ()
{
  if (_ != 2)
    abort ();
  return 0;
}