As part of a bugfix I did today ((Thanks, as always, to my employer, Collabora, for letting me work on Empathy)), I made a commit to remove a redundant class from Empathy, which made me wonder if there were any other redundant classes in Empathy. A quick grep of G_DEFINE_ told me there are some 116 classes in Empathy, so I wasn’t going to check them all by hand.
Instead I put together this script, which I share with you in case it’s useful, which basically checks for all classes defined with G_DEFINE_TYPE and then looks to see if anything with that namespace is used in another file. It generates false positives for classes that aren’t used outside the file they’re defined in, or classes that have different namespaces to the classname, but it produces a much more manageable list.
I did consider looking for unused symbols, but couldn’t work out an easy way to do it properly. Empathy’s compile process is split into two archive libraries (libempathy.a and libempathy-gtk.a) and several binaries (empathy, empathy-call, empathy-accounts, etc.), so I couldn’t think of a way to ask the linker to find any unused symbols. I put together this second script, which will build a list of symbols in archives and look for those symbols copied into the binaries, which gets some of the way there, but will miss any unused symbols defined in the binaries’ sources (src/).