Use llvm/clang trunk with XCode 4.3

1. Install homebrew: https://github.com/mxcl/homebrew/wiki/installation
2. Install llvm-head with clang: brew install –HEAD –with-clang –analyzer –rtti –jit llvm
3. Create a User-Defined variable in your Xcode project
   • Variable name: CC
   • Value: /usr/local/bin/clang
4. Enjoy!

Reference: http://blog.wadetregaskis.com/tot-clang-llvm-in-xcode/