Building Clang from source

If you would like to build Clang (and lld) from source for testing purposes, it is really easy! You should have cmake and ninja installed from your distribution.

$ git clone git://github.com/llvm/llvm-project
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -G Ninja \
        -DCMAKE_BUILD_TYPE=Release \
        -DLLVM_ENABLE_PROJECTS="clang;lld;compiler-rt" \
        -DLLVM_ENABLE_WARNINGS=OFF \
        ../llvm
$ ninja

You are interested in more optimized binaries and faster compile times? You are invited to use tc-build!

Example: Build Clang and LLD (projects) for X86 (targets) arch-only in a "stage1" build-only

$ git clone git://github.com/ClangBuiltLinux/tc-build
$ cd tc-build
$ ./build-llvm.py --help
$ ./build-llvm.py --projects "clang;lld" --targets "X86" --build-stage1-only

Please see that repo's README for more informations.