bzlmod support

[jsharpe]

Create bzlmod module extensions and submit an entry to https://github.com/bazelbuild/bazel-central-registry

[siddharthab]

Opened bazelbuild/bazel-central-registry#923.

[jsharpe]

Note that currently the llvm extension doesn't forward all the attributes to the llvm_toolchain rule so e.g. cxx_standard is currently broken.

[siddharthab]

So sorry I did not notice it in the review. What's the best way to forward all the attributes rather than copy/pasting?

[jsharpe]

I'm not exactly sure; there are a lot of attributes that need to be forwarded but so you would want to do the equivalent of (**tag_class.attrs) on the call to the rule. I'm not sure if that works though? Can give it a try..

[siddharthab]

Resolved by #218. When you are done testing, I can cut a new patch release.

[siddharthab]

Also please feel free to send PRs as you are testing. Will make the whole process much easier. I no longer use this project in any major codebase, so the unit tests here are the only things I run.

[jlisee]

The release notes for 0.10.2 have instructions on how to use Bzlmod but how do we do that if bazelbuild/bazel-central-registry#923 has not yet landed in the central registry?

From looking at your commit history you have an override like this, do still need something similar:

git_override(module_name = "toolchains_llvm", remote = "https://github.com/grailbio/bazel-toolchain", commit = "e4fad4e6c1821d805ffd9c21bdd6e2cc52764862")

EDIT - fixed the override to match 0.10.2 and use toolchains_llvm

[siddharthab]

Yes, I had hoped that the inclusion into BCR would be quick but it has taken some time. git_override would be a good way to do this. You can keep the module_name to be "toolchains_llvm". I will add this detail to the release notes.

[siddharthab]

https://github.com/grailbio/bazel-toolchain/releases/tag/0.10.3

[siddharthab]

https://registry.bazel.build/modules/toolchains_llvm