------- Additional Comments From rguenth at gcc dot gnu dot org 2005-08-11
10:44 -------
We inline all and get
void bar() ()
{
char & D.1777;
struct B * D.1776;
char & D.1773;
union C D.1772;
<bb 0>:
D.1772.p = &a;
D.1776_5 = D.1772.q;
D.1777_6 = &D.1776_5->d;
D.1773_7 = D.1777_6;
*D.1773_7 = 0;
return;
}
where we access the padding between c and i in struct A through an
object of type B. This must be invalid code. Even if it is, the
gcc_unreachable () is probably not a good idea - Danny, how should
we deal with this? Ignore references to padding and just return
NULL from first_vi_for_offset?
There's a similar problem in get_constraint_for_component_ref which
I hit with array-aliasing and work-around by
*************** get_constraint_for_component_ref (tree t
*** 2075,2082 ****
}
/* assert that we found *some* field there. The user couldn't be
accessing *only* padding. */
!
! gcc_assert (curr);
}
else
if (dump_file && (dump_flags & TDF_DETAILS))
--- 2076,2084 ----
}
/* assert that we found *some* field there. The user couldn't be
accessing *only* padding. */
! /* Still the user could access one past the end of an array
! embedded in a struct resulting in accessing *only* padding. */
! /* gcc_assert (curr); */
}
else
if (dump_file && (dump_flags & TDF_DETAILS))
--
What |Removed |Added
----------------------------------------------------------------------------
CC| |rguenth at gcc dot gnu dot
| |org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=22615
