How to traverse through all type declarations in a compilation module?

["Haifeng He" <hehaifeng2nd@xxxxxxxxx>]

Hi,

I would like to know what types were defined in a compilation module?
For example, suppose in a program, user defines
struct A, B, C. I would like to get the type information of all these
struct (I am using GIMBLE representation. )
Where does GCC store the those type informations and how can I get them?

Thanks

Haifeng