Purpose of unwind.h in libunwind and clang Headers

Clang Frontend
#1

Hello everyone!

I am wondering what the purpose of having both unwind.h in libunwind and the clang Headers is. I see that they have quite a lot but not fully equal declarations. I am asking because currently I am running into issues building libc++abi with llvm libunwind support on Windows as the include here: https://github.com/llvm/llvm-project/blob/8f3d47c54ac21f99b25d8ad00598b7f5be00d6d8/libcxxabi/src/cxa_personality.cpp#L23 includes the libunwind unwind.h instead of the one from the clang resource folder. This leads to a build failure as _Unwind_Personality_Fn used below is not defined in llvm libunwind.

Would fixing this just require fixing the include paths in cmake or is the problem somewhere deeper?

Regards
Markus Böck

#2

I believe they are supposed to be mostly interchangeable (probably with nontrivial historic reasons to why there's two different similar files), so in this case the exising __personality_routine typedef in libunwind's unwind.h could be typedeffed to the _Unwind_Personality_Fn name as well.

// Martin