Years ago, I stumbled upon a Visual C++ 6.0 bug (if memory serves me right), just by playing around trying to understand C/C++ decls. It would crash on a stray:

   *c;

at the beginning of a translation unit.

Didn't K&R have a tiny, tiny C declarations parser (printing out 'human readable' equivalents) example in their book? I think the caveat was that it needs to assume it's dealing with a declaration...