[Bug target/47558] 163267 breaks exception traceback in xplor-nih

["howarth at nitro dot med.uc.edu" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47558

--- Comment #59 from Jack Howarth <howarth at nitro dot med.uc.edu> 2011-02-05 18:40:15 UTC ---
I can confirm that the patch in Comment 58 both eliminates the failure in the
reduced test case from Comment 56 as well as the failure in the dipCoup test in
xplor-nih. I am less certain that we want the
current phrasing of the comment...

+/* FIXME: Work around PR47558 by linking against libSystem ahead of 
+   libgcc_ext. */

We should arrive at a consensus on whether symbols which overlap between
libgcc_ext and libSystem should be given priority in libSystem and resolved
there. This patch achieves this and if we agree this should be the case, the
comment should instead read...

+/* Linking libSystem ahead of libgcc_ext prioritizes those overlapping symbols
in libSystem
+    over those from libgcc_ext which re-exposes PR42333. */

This is the correct behavior for the long-run on darwin and we should re-double
our efforts to get
<rdar://problem/7457013>,  ___divdc3 slightly wrong, fixed in Lion.