1  extern void abort (void);
       2  
       3  int foo (int size)
       4  {
       5    int a[size];
       6    a[size - 10] = 42;
       7    return a[size - 10] + size;
       8  }
       9  
      10  int
      11  main()
      12  {
      13    int x = foo (20);
      14    if (x != 62)
      15      abort ();
      16    return 0;
      17  }