https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66848
--- Comment #13 from Jack Howarth <howarth.at.gcc at gmail dot com> --- (In reply to m...@gcc.gnu.org from comment #12) > Is this just a partial import from upstream? If so, I think we should just > check it in and call the issue solved. No, the patch shown is an ugly hack of reducing the alignment to 2 (or 1) which merely suppresses the breakage of boehm-gc (and thus gcj) under the Apple Clang 7.0 compiled libunwind.dylib on darwin15. The newer upstream boehm-gc uses the same alignments as gcc's boehm-gc but doesn't suffer the test suite failures. All I can say at the moment is that the bug seems to be alignment related. However it is unclear to me if the bug actually lies in gcc's current boehm-gc or whether the breakage really lies in the Apple Clang 7.0 optimizations to the system unwinder and that the newer upstream boehm-gc merely makes the bug go latent. Apple claims these new optimizations to the unwinder are valid but I really doubt that the bug has been truly examined in depth to validate that .
