This bug is similar to http://gcc.gnu.org/PR24255 in that instead of passing
the pointer to the variable itself a pointer to a temporary holding the address
of the variable is used. However, the test case (which I will attach next)
doesn't start failing until the following patch (found with Janis' reghunt
scripts):
2007-10-09 Richard Guenther <rguent...@suse.de>
PR middle-end/33692
* gimplify.c (canonicalize_component_ref): Honor qualifiers
of referenced structure and component.
* gcc.dg/pr33692.c: New testcase.
The problematic union looks like:
union q
{
unsigned n;
unsigned get_n () const { return n; }
} __attribute__ ((transparent_union));
If I change the second field to basically anything else, the test case passes.
This seems to be a regression with GCC 4.4, 4.5 and mainline, as it compiles
fine with my GCC 4.3 based system compiler which predates richi's patch.
I'll note this only seems to fail using "g++ -m32 ..." and does not fail when
using -m64.
--
Summary: transparent_union mishandled
Product: gcc
Version: 4.6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: bergner at gcc dot gnu dot org
GCC build triplet: powerpc64-linux
GCC host triplet: powerpc64-linux
GCC target triplet: powerpc64-linux
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43859
