https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84340
--- Comment #10 from Paolo Bonzini <bonzini at gnu dot org> ---
> Note that we only instrument ASAN_CHECK for memory references. x=0 is not
> that
> case.
That depends... in use-after-scope-types-1.C there is inlining involved. With
my pass ordering change ASAN_CHECK is added before inlining, when there is
still a *ptr.t dereference. After inlining you get:
ASAN_MARK (UNPOISON, &ptr, 8);
ASAN_MARK (UNPOISON, &x, 1);
ASAN_CHECK (7, &ptr.t, 8, 8);
_9 = &ptr.t;
ASAN_CHECK (7, _9, 8, 8);
ptr.t = &x;
ASAN_MARK (POISON, &x, 1);
ASAN_CHECK (6, &ptr.t, 8, 8);
ASAN_CHECK (7, &x, 1, 1);
_10 = &x;
ASAN_CHECK (7, _10, 1, 8);
x = 0;
ASAN_MARK (POISON, &ptr, 8);
But even if this weren't the case, the ASAN_MARK would be lowered to
ASAN_POISON() and everything seems to work:
int main()
{
bool *ptr;
{
bool x;
ptr = &x;
}
return *ptr;
}
becomes
x_8 = ASAN_POISON ();
_6 = (int) x_8;
return _6;
(and it is very similar to gcc.dg/asan/use-after-scope-10.c).
