1 2 extern void abort(void); 3 4 __attribute__ ((noinline)) foo(int n)5 int foo(int n) 6 { 7 if (n < 0) 8 n = ~n; 9 10 return n; 11 } 12 main(void)13 int main(void) 14 { 15 if (foo (-1) != 0) 16 abort (); 17 18 return 0; 19 } 20