modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/pushpop_macro.c (about)

     1  extern void abort ();
     2  
     3  #define _ 2
     4  #pragma push_macro("_")
     5  #undef _
     6  #define _ 1
     7  #pragma pop_macro("_")
     8  
     9  int main ()
    10  {
    11    if (_ != 2)
    12      abort ();
    13    return 0;
    14  }
    15