Add x_explicit_api_mode to remaining kotlinc_options

[pettermahlen]

See https://github.com/Kotlin/KEEP/blob/master/proposals/explicit-api-mode.md for more about the switch itself.

I'm not sure how to test this - the best test would be to have some test code with default access modifiers and explicit-api=strict set, and then run a compilation and verify that it fails. That seems complex, and like it would require a fair amount of tooling, which I'm not sure if it's available. Please advice if so.

[Bencodes]

Support for this was already added here #576. Does it not work?

[pettermahlen]

No, it's not working, for some reason, although I hadn't even noticed this PR, nor the fact that the options are in fact documented here https://bazelbuild.github.io/rules_kotlin/kotlin.html#kt_kotlinc_options...

I'm new to Bazel, but it looks like the opts.bzl that gets pulled in locally is from /private/var/tmp/_bazel_petter/602bfdc6fd57d9ddfc7aad7b3ee3cb9e/external/io_bazel_rules_kotlin_configured/kotlin/opts.bzl, which doesn't contain the explicit API setting. The version we're pulling in is v1.5.0-beta-4, which AFAICT should contain #576. Is there some configuration option that is wrong, perhaps? (Thinking about the _configured suffix).

[pettermahlen]

Hm, the reason I made this change was that my BUILD file does the following load (as per the README):

load("@io_bazel_rules_kotlin//kotlin:core.bzl", "kt_kotlinc_options")

And AFAICT, core.bzl loads from kotlin/internal, or https://github.com/bazelbuild/rules_kotlin/blob/master/kotlin/internal/opts.bzl, which in turn points to the files I changed in this PR. Assuming I read the code right, I am a complete newbie as mentioned.

There seems to be 8 opts.bzl files in the repo (including one named opts.release.bzl). Is that what's causing the issue?

[Bencodes]

Ah so the solution here is to replicate the existing x_explicit_api_mode option in the newly added opts files that are missing this explicit api mode attribute. Do you want to update your PR to do that?

[pettermahlen]

Done. AFAICT, it was only the 1.5 file that was missing the option.

[Bencodes]

Lgtm but @cgruber or @restingbull will need to merge this