I am trying to build libunwind on Mac for both iOS and Mac, I was able to resolve few of the compilation problem.
Building on Mac
I configured the project using
./configure CC="cc -Ae -D_XOPEN_SOURCE=500"
/usr/include/elf.h:58:15: fatal error: 'elf.h' file not found
I got an answer from libunwind developer forum.
I don't think it will work. There's no OS X support in libunwind at the moment, and the platform is quite different. There is a sort of a libunwind (which has little or nothing to do with this one) in the OS itself though. See http://opensource.apple.com/source/libunwind/ There's also some sort of symbolization library for post-processing. IIRC you more or less want to use the tools that ship with base OS or at least Xcode, otherwise you are up against writing quite a lot of tooling yourself.
In short libunwind is not supported on Mac OS X.