In all honesty, I don't have a tonne of experience with setting up code coverage in non-Golang environments.

I think that https://coveralls.io looks very nice and has a good interface. That said, I'm always a little bit wary to adopt SaaS when there could be a more "long lived" solution. (for example, choosing astyle over clang-format despite astyle existing on Sourceforge)

I was recommended gcov as well. I'm probably going to read the manual for gcov and then give it a go. If anyone has firm opinions and/or recommendations, I would be very interested to hear them.

Seems like a lot of C test coverage tools are proprietary.