====== Use llvm/clang trunk with XCode 4.3 ======

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

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