如何制作一个干净的铿锵前端？

I'm working on a C++ source analyzer project and it seems that clang is nice candidate for the parsing work. The problem is that clang heavily depends on the infrastructure "llvm" project, How do I configure it to get a clean front-end without any concrete machine oriented backend? Just like LCC does, they provide a "null" backend for people who focus on parser parts. Any suggestion is appreciated.I'm working on a C++ source analyzer project an