1 // RUN: %clangxx_msan -O2 %s -o %t && %run %t 2 3 #include <sanitizer/msan_interface.h> 4 5 struct S { SS6 S(int a0) : a(a0) {} 7 int a; 8 int b; 9 }; 10 11 // Here S is passed to FooRun as a 64-bit integer. 12 // This triggers an optimization where 10000 * s.a is transformed into 13 // ((*(uint64_t *)&s) * (10000 * 2**32)) >> 32 14 // Test that MSan understands that this kills the uninitialized high half of S 15 // (i.e. S::b). FooRun(S s)16void FooRun(S s) { 17 int64_t x = 10000 * s.a; 18 __msan_check_mem_is_initialized(&x, sizeof(x)); 19 } 20 main(void)21int main(void) { 22 S z(1); 23 // Take &z to ensure that it is built on stack. 24 S *volatile p = &z; 25 FooRun(z); 26 return 0; 27 } 28