A couple of developers are working to replace GCC in the FreeBSD base system with clang/LLVM. Clang is a compiler built on the Low Level Virtual Machine compiler infrastructure. Both clang and llvm are released under a BSD like license, unlike GCC that’s GPL licensed.

Roman Divacky has an update on the project:

The situation as of late September:

  • i386 – kernel boots, world needs little hacks but works
  • amd64 – kernel compiles but does not boot, world needs little hacks
  • ppc – broken because of unknown RTLD bug

All other platforms are untested. Ie. this is a regression from the situation in early spring when we could boot amd64 as well…

A lot has happened over the spring/summer – amd64 got proper mcmodel=kernel support, compiler-rt was introduced (paving the way for libgcc replacement), we ran two experimental ports build to see how clang does there, C++ support is able to parse devd.cc without warnings, we got kernel working with -O2, we promoted FreeBSD to be officially supported plaform in LLVM etc. etc.

The developers could do with a bit of support and help with the testing. Can you?

We have problems though: we don’t have manpower for testing (thats why amd64 kernel stopped booting) and developers for integrating stuff into FreeBSD (maintaining ports etc.). So if you are interested in helping please contact me or join us on IRC in #freebsd-clang on irc.oftc.net. We especially need amd64 testers (because of the amd64 kernel bug) and people with minor platforms like arm/mips/sparc to see how clang/llvm performs there and improve that