GCC Dehydra allows us to do analysis passes on our existing code. In the far future it may also allow us to do optimization passes. But it does not have the ability to do code rewriting, and probably won’t gain that ability any time soon. In order to be able to do C++->C++ transformations, you have to have correct end positions for all statements/tokens, not just beginning positions. GCC does not track this information, and making it do so would be a massive undertaking.
Mozilla2 still lives in a dual world where automatic code refactoring is done using the elsa/oink toolchain, while static analysis is taking place using the GCC toolchain.