Granted, this may not be at all what you are looking for, but depending on your needs, it might be just the trick.

Doxygen generates JavaDoc-like documentation for projects in many languages, including C and C++. DoxygenFilter is a new take on an old project (DoxyFilt) that also handles ("filters") Perl code, and now promises support for multi-programming-language projects. See Examples of output generated by doxygen.

HTH,