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!

$ git clone https://github.com/ClangBuiltLinux/tc-build $ cd tc-build $ ./build-llvm.py 

If you do not have as powerful of a machine or are time restricted in some other way, you can build just Clang and LLD in a "stage 1" configuration (rather than the default of building a smaller clang and lld to build a fuller LLVM toolchain afterwards).

$ ./build-llvm.py --projects clang lld --build-stage1-only 

Please see that repo's README for more information on properly using it.