Really? That's probably why I failed! Ironically (given my post) I've never looked at Clang's parser. I have looked at GCC's and, well, sheepishly: I don't get it, it is a beast of a project and I wasn't able to crack the architecture. I should try again tho.
C is almost context-free with the exception of typedef. A custom parser helps with error diagnostics, e.g. missed semicolon or a "." swapped with "->".
