[Bug target/44107] gcc emits frame (epilogue) info incompatible with the darwin {8,9}-unwinder,10-compacter

[howarth at nitro dot med.uc.edu]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=44107

--- Comment #24 from Jack Howarth <howarth at nitro dot med.uc.edu> ---
(In reply to David Fang from comment #22)
> Do one of these apple libunwind sources (0.30, 0.35.1) correspond to what's
> bundled in libgcc_s in darwin8,9,10?
> 
> http://opensource.apple.com/tarballs/libunwind/

No. The libunwind sources are the replacement compact and compatibility
unwinders that Apple introduced in 10.7. You will see that the 0.30 release
first appears at http://www.opensource.apple.com/release/mac-os-x-107/. Note
that if you look at
http://www.opensource.apple.com/source/libgcc/libgcc-13/stub.c from 10.6.8, you
will see that the unwinder calls resided in libgcc_s up to 10.5 after which
they were subsumed into libSystem. I am unclear if the subsumed unwinder calls
in 10.6.x were based on the code from libgcc but these certainly aren't based
on libunwind. Since Apple never released the source code for theses files, it
is difficult to know their heritage in 10.6.x. Also see...

http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-September/025894.html
http://lists.cs.uiuc.edu/pipermail/llvmdev/2009-September/025898.html