1 volatile int x; 2 sink()3void __attribute__((noinline)) sink() { 4 x++; /* break here */ 5 } 6 func3()7void __attribute__((noinline)) func3() { sink(); /* tail */ } 8 func2()9void __attribute__((disable_tail_calls, noinline)) func2() { func3(); /* regular */ } 10 func1()11void __attribute__((noinline)) func1() { func2(); /* tail */ } 12 main()13int __attribute__((disable_tail_calls)) main() { 14 func1(); /* regular */ 15 return 0; 16 } 17