what's required to support shared libs?

[milianw]

Hey all,

this sounds like a great addition to the tooling landscape, thank you very much! I would love to try it out, but your constraints page says:

Statically linked binaries only

This is sadly a deal breaker for my world. Can someone share some details on what's blocking shared library support? Maybe I can help you out and add the required bits and pieces for that - unless you are saying this is conceptually impossible (why?).

Thanks again!

[ttreyer]

Hey @milianw,

Thanks a lot for having a look at OI!

Since we focused on statically linked binary, we really haven't tested how Object Introspection handles shared libraries. So we could certainly do with some help for supporting them 🙂

The two area that should be affected by shared libraries are: locating Symbols and reading Debug Info. We rely on elfutils' libdwfl and drgn's libdrgn to handle these two tasks for us. I believe they're both able to handle multiple executables/libraries, but OI might not leverage their APIs to do so.

What I would suggest doing is:

1. Try oid on a dynamically linked executable.
2. If it doesn't work then have a look at the SymbolService in oi/SymbolService.{h,cpp}:
   a. Ensure SymbolService::loadModules loads the shared libraries in libdwfl.
   b. Ensure SymbolService::getDrgnProgram loads the Debug Infos of the shared libraries into libdrgn.

We'll happily work with you on this feature and feel free to get in touch if you have any question!