Before sending this to XLS internal reviewers, does this look good @cdleary ?

Do you still want to land? Is this superseded by #3184?

Yes, still want to land.
In #3184 I explicitly broke out the changes in xls/public as I was waiting on this one separately.

Well, this looks good to me. I'm inclined to land unless @cdleary opposes, it's also not hard to revert/fix later if need be.

I think for the header it's useful to have the central .h file roll up all the public APIs, for the cc doesn't matter though.

At least internally, it looks like xlsynth relies on the BUILD dep else a linker error complaining about missing symbols from c_api_vast. @cdleary do you want to keep the BUILD dep or explicitly depend on c_api_vast in xlsynth?

@grebe I need a target that rolls up all the C API symbols as a DSO, that was libxls.so which is the shared library wrapper of c_api AFAIK -- it'd be nice to not break that for header cleanliness :-) we need something that is canonically "libxls with all its symbols"

Makes sense, I think an IWYU: pragma export makes sense then as that will keep the bazel dep as well. @hzeller do you mind making the change?

Done. Added the // IWYU: pragma export and re-added the :c_api_vast to //xls/public:c_api

the ci failure looks unrelated.

Yeah, CI is a known issue.