Replace hardcoded -g0 with toolchain features

[keith]

Must be paired with a rules_cc version bump that includes bazelbuild/rules_cc#649

Fixes #13308
Fixes #24545

RELNOTES[inc]: Remove default -g0 for host tools. This is still added with the default CC toolchains or if you don't set no_legacy_features

[keith]

cc @gregestren

[gregestren]

Nice simplification!

Must be paired with a rules_cc version bump that includes bazelbuild/rules_cc#649

What's the right merge sequence? Given that presubmit CI isn't failing, Bazel's core CI doesn't cover this?

[keith]

yea ideally we would merge the rules_cc change, create a release, and then i would pull that release bump into this change.

i think the risk of merging them out of sync is actually that internal google toolchains are expecting this and don't get it. because the default public toolchains default to having this for opt, so only folks who override the opt flags wouldn't get this behavior.

[gregestren]

Okay, we can put this into the internal merge queue and see what happens?

[keith]

@gregestren how'd this one go

[gregestren]

I just wanted to double-check with @trybka for merging . Re-pinged.

[gregestren]

Googlers are discussing some proprietary toolchain issues. I'm trying to track that but I think in a worst case we could fork Google's exec configuration to keep -g0 without making that a Bazel-wide problem.

[trybka]

Yeah, we tried to import bazelbuild/rules_cc#649 and ran into issues, trying to sort those out.

Landing this will also require either an exec config fork in the interim or other toolchain additions (i.e. setting -g0 in exec). But doing so would require landing rules_cc PR#649 first.