Version of LLVM used in Xcode 9.1


I’m wondering which LLVM upstream version is used in “Apple LLVM version 9.0.0 (clang-900.0.38)” included in the latest stable Xcode 9.1?

The last source code published by Apple was which used LLVM 3.9 version (according to CMakeLists.txt).

Best regards,

The version you mention indicates when the release version was branched from, but then during stabilization many bugfixes are cherry-picked on top of that. I would recommend looking at the various Swift release branches of llvm and clang at and to get a more complete picture.

– adrian


I already asked a similar question few months ago, see

Thank you guys! It seems the current Xcode 9.1 uses LLVM 4.0 and the upcoming release (the one which will include Swift 4.1) will use at least LLVM 5.0 (already merged).