1 volatile int x;
2 
3 void __attribute__((noinline)) sink() {
4   x++; //% self.filecheck("bt", "main.cpp", "-implicit-check-not=artificial")
5   // CHECK: frame #0: 0x{{[0-9a-f]+}} a.out`sink() at main.cpp:[[@LINE-1]]:4 [opt]
6   // CHECK-NEXT: frame #1: 0x{{[0-9a-f]+}} a.out`func3() at main.cpp:14:3 [opt] [artificial]
7   // CHECK-NEXT: frame #2: 0x{{[0-9a-f]+}} a.out`func2() {{.*}} [opt]
8   // CHECK-NEXT: frame #3: 0x{{[0-9a-f]+}} a.out`func1() at main.cpp:23:3 [opt] [artificial]
9   // CHECK-NEXT: frame #4: 0x{{[0-9a-f]+}} a.out`main{{.*}} [opt]
10 }
11 
12 void __attribute__((noinline)) func3() {
13   x++;
14   sink(); /* tail */
15 }
16 
17 void __attribute__((disable_tail_calls, noinline)) func2() {
18   func3(); /* regular */
19 }
20 
21 void __attribute__((noinline)) func1() {
22   x++;
23   func2(); /* tail */
24 }
25 
26 int __attribute__((disable_tail_calls)) main() {
27   // DEBUG: self.runCmd("log enable lldb step -f /tmp/lldbstep.log")
28   func1(); /* regular */
29   return 0;
30 }
31