modernc.org/ccgo/v3@v3.16.14/lib/testdata/gcc-9.1.0/gcc/testsuite/gcc.c-torture/execute/pr21964-1.c (about)

     1  void
     2  foo (int n, int m)
     3  {
     4    if (m == 0)
     5      exit (0);
     6    else if (n != 0)
     7      abort ();
     8    else
     9      foo (n++, m - 1);
    10  }
    11   
    12  int
    13  main (void)
    14  {
    15    foo (0, 4);
    16  }