| // RUN: %clangxx_msan -O2 %s -o %t && %run %t | |
| #include <sanitizer/msan_interface.h> | |
| struct S { | |
| S(int a0) : a(a0) {} | |
| int a; | |
| int b; | |
| }; | |
| // Here S is passed to FooRun as a 64-bit integer. | |
| // This triggers an optimization where 10000 * s.a is transformed into | |
| // ((*(uint64_t *)&s) * (10000 * 2**32)) >> 32 | |
| // Test that MSan understands that this kills the uninitialized high half of S | |
| // (i.e. S::b). | |
| void FooRun(S s) { | |
| int64_t x = 10000 * s.a; | |
| __msan_check_mem_is_initialized(&x, sizeof(x)); | |
| } | |
| int main(void) { | |
| S z(1); | |
| // Take &z to ensure that it is built on stack. | |
| S *volatile p = &z; | |
| FooRun(z); | |
| return 0; | |
| } |