1void abort (void); 2 3int j; 4 5void bla (int *r) 6{ 7 int *p, *q; 8 9 p = q = r; 10 if (!p) 11 p = &j; 12 13 if (p != q) 14 j = 1; 15} 16 17int main (void) 18{ 19 bla (0); 20 if (!j) 21 abort (); 22 return 0; 23} 24