I asked the guy working on compiler-rt to change one boolean so the LLVM 18 build would work on macOS, and he locked the whole issue down as "heated" and it's still not fixed four years later.

I love LLVM though. clang-tidy, ASAN, UBSAN, LSAN, MSAN, and TSAN are AMAZING. If you are coding C and C++ and NOT using clang-tidy, you are doing it wrong.

My biggest problem with LLVM rn is that -fbounds-safety is only available on Xcode/AppleClang and not LLVM Clang. MSAN and LSAN are only available on LLVM and not Xcode/AppleClang. Also Xcode doesn't ship clang-tidy, clang-format, or llvm-symbolizer. It's kind of a mess on macOS rn. I basically rolled my own darwin LLVM for LSAN and clang-tidy support.

The situation on Linux is even weirder. RHEL doesn't ship libcxx, but Fedora does ship it. No distro has libcxx instrumented for MSAN at the moment which means rolling your own.

What would be amazing is if some distro would just ship native LLVM with all the things working out of the box. Fedora is really close right now, but I still have to build compiler-rt manually for MSAN support..