This might change though, now that GCC has some stiff open source competition. I heard GCC is partly a bit of a hairball to prevent GPL loopholes. They wanted

This might change though, now that GCC has some stiff open source competition. I heard GCC is partly a bit of a hairball to prevent GPL loopholes. They wanted to ensure you can't wrap it in some kind of RPC framework to get around the GNU GPL. They might clean things up a bit, if there's no longer an incentive for people to want to effectively steal it (since they can just use Clang instead). In fact, open source projects (even GLP ones) might start switching to Clang, if it has a cleaner API. So the costs of a hairy API are going to start outweighing the benefits.