You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

55 lines
1.1 KiB

// Verifies that speculative loads from unions do not happen under asan.
// RUN: %clangxx_asan -O0 %s -o %t && %run %t 2>&1
// RUN: %clangxx_asan -O1 %s -o %t && %run %t 2>&1
// RUN: %clangxx_asan -O2 %s -o %t && %run %t 2>&1
// RUN: %clangxx_asan -O3 %s -o %t && %run %t 2>&1
#include <sanitizer/asan_interface.h>
struct S {
struct _long {
void* _pad;
const char* _ptr;
};
struct _short {
unsigned char _size;
char _ch[23];
};
union {
_short _s;
_long _l;
} _data;
S() {
_data._s._size = 0;
__asan_poison_memory_region(_data._s._ch, 23);
}
~S() {
__asan_unpoison_memory_region(_data._s._ch, 23);
}
bool is_long() const {
return _data._s._size & 1;
}
const char* get_pointer() const {
return is_long() ? _data._l._ptr : _data._s._ch;
}
};
inline void side_effect(const void *arg) {
__asm__ __volatile__("" : : "r" (arg) : "memory");
}
int main(int argc, char **argv) {
S s;
side_effect(&s); // optimizer is too smart otherwise
const char *ptr = s.get_pointer();
side_effect(ptr); // force use ptr
return 0;
}