volatile int x; // clang-format off void __attribute__((noinline)) tail_call_sink() { x++; //% self.filecheck("bt", "main.cpp", "-check-prefix=TAIL-CALL-SINK") // TAIL-CALL-SINK: frame #0: 0x{{[0-9a-f]+}} a.out`tail_call_sink() at main.cpp:[[@LINE-1]]:4 // TAIL-CALL-SINK-NEXT: inlinable_function_which_tail_calls() at main.cpp{{.*}} [artificial] // TAIL-CALL-SINK-NEXT: main{{.*}} } // clang-format on void __attribute__((always_inline)) inlinable_function_which_tail_calls() { tail_call_sink(); } void __attribute__((noinline)) func3() { inlinable_function_which_tail_calls(); } // clang-format off void __attribute__((always_inline)) inline_sink() { x++; //% self.filecheck("bt", "main.cpp", "-check-prefix=INLINE-SINK") // INLINE-SINK: frame #0: 0x{{[0-9a-f]+}} a.out`inline_sink() at main.cpp:[[@LINE-1]]:4 // INLINE-SINK-NEXT: func2{{.*}} // INLINE-SINK-NEXT: func1{{.*}} [artificial] // INLINE-SINK-NEXT: main{{.*}} } // clang-format on void __attribute__((noinline)) func2() { inline_sink(); /* inlined */ } void __attribute__((noinline)) func1() { func2(); /* tail */ } int __attribute__((disable_tail_calls)) main() { // First, call a function that tail-calls a function, which itself inlines // a third function. func1(); // Next, call a function which contains an inlined tail-call. func3(); return 0; }