Coveralls support

[kennytm]

• Produce coveralls-compatible branch coverage JSON info
• Upload from Travis CI to coveralls
• Upload from AppVeyor to coveralls

API reference: https://coveralls.zendesk.com/hc/en-us/articles/201350799-API-Reference

Maybe use https://crates.io/crates/coveralls-api

[marco-c]

Have you considered using grcov for parsing and output generation?

[kennytm]

@marco-c Thanks, but

GCC 4.9 or higher is required.

Unless it is independent of the C compilers, nope.

[marco-c]

It doesn't support GCC < 4.9, but it does support GCC >= 4.9 and LLVM.

Are you interested in GCC < 4.9 support? It's a very old compiler, so I didn't bother, but if your project requires it I can add support.

[kennytm]

@marco-c I thought it means GCC needs to be installed? Also I saw the build.rs which references llvm-config that does not exist in $PATH of macOS.

---

Anyway this project (kennytm/cov) is currently very inactive because the coverage is useless when unused generic functions are simply ignored...

[marco-c]

@marco-c I thought it means GCC needs to be installed?

I need to fix the docs, GCC doesn't need to be installed if you want to parse gcno/gcda files generated via LLVM.

Also I saw the build.rs which references llvm-config that does not exist in $PATH of macOS.

Yes, it does require the LLVM libs because it is using the LLVM API to parse the gcno/gcda files.

[marco-c]

@kennytm note llvm-config is only needed to build, but nothing is required at runtime. I'm using the LLVM API to make sure I pick up any change to the gcno/gcda format.