20011109-1.c

this is a gcc file, you can download it and learn its usetility, for further detail please look at t

void fail1(void)
{
  abort ();
}
void fail2(void)
{
  abort ();
}
void fail3(void)
{
  abort ();
}
void fail4(void)
{
  abort ();
}


void foo(long x)
{
  switch (x)
    {
    case -6: 
      fail1 (); break;
    case 0: 
      fail2 (); break;
    case 1: case 2: 
      break;
    case 3: case 4: case 5: 
      fail3 ();
      break;
    default:
      fail4 ();
      break;
    }
  switch (x)
    {
      
    case -3: 
      fail1 (); break;
    case 0: case 4: 
      fail2 (); break;
    case 1: case 3: 
      break;
    case 2: case 8: 
      abort ();
      break;
    default:
      fail4 ();
      break;
    }
}

int main(void)
{
  foo (1);
  exit (0);
}