I've got a small bash script to find the interesting files, then, for each such file, a Perl scrict is called. This perlscript is supposed to find all properties, events, relations, methods, etc. and simply output a class header and an implementation.
With my current version I find all the info that I need, but I only present it as a table. The next step will be to exchange the backend with a C++ code generator and hopefully, simply compile away. I know that their might be some fuzz with the GWidget base class, but doing 1 class out of 120 is pretty good, compared to that I actually concidered doing it all by hand.
I would like to thank Larry Wall and everyone else who has made Perl such a nice and powerful language!