I\'m trying to work on a kind of code generator to help unit-testing an legacy C/C++ blended project. I don\'t find any kind of independent tool can generate stub code from decl
For another approach, you could consider piggy-backing on an existing compiler.
GCC-XML will "compile" C++ into XML files with a lot of useful information; it may be enough for your purposes.
Unfortunately, GCC-XML is only 1/4-maintained, and getting it to work can be...interesting. Good luck, if you go this route.