DOCBOOK: generating a reference manual from source code

Hi there,

I'm trying to generate a docbook document that is more or less a mapping
from a source file (a header in case of C++) to xml, including inlined
documentation.
I have written a tool that generates an Abstract Syntax Tree out of various
sources (right now IDL, C++, and python), and I'm using a 'visitor' to
traverse that tree and generate appropriate output. The difficult part is
to come up with AST nodes that are descriptive and general at the same time,
such that they can serve a variety of languages...

However, in case of docbook I'm missing a couple of entities (or is it just
the documentation that lacks...?): typedefs, modules, enums for example
are missing.

Is there any document that I could consult to get more information about
the kind of problem I'm trying to solve ?

Thanks a lot,	
		Stefan

PS: I'm using docbook xml 4.1.2 and the docbook 4.0 update reference

PPS: the tool I'm talking about is synopsis: http://synopsis.sourceforge.net/