xcode 4 and clang+llvm

Hi Everyone,
I am working on the new mac os lion and I downloaded the new Xcode 4.3, which comes with
llvm. I am in the process of writing some code transformations but i am not sure how to
go about it because I can’t find the Transforms directory. I can install llvm from source but that will be like installing it twice. Any help is greatly appreciated. Thanks.