Apply clang-format to cub

[bdice]

Description

This applies clang-format to CUB. With #1588 and the pre-commit.ci bot, autoformatting can be applied to any PR by commenting pre-commit.ci autofix.

All changes were automatically applied aside from the edits to .pre-commit-config.yaml.

See also:

• [EPIC]: Set up automatic and consistent code formatting with clang-format #455
• Automatic code formatting in PRs #456
• Setup pre-commit.ci for automated linter enforcement and applying changes #1589

Checklist

• New or existing tests cover these changes.
• The documentation is up to date with these changes.

[bdice]

This is a starting point for discussion -- I am open to any/all feedback on this PR. Some questions:

• Is the .clang-format configuration exactly what we want, or should we tweak it first?
• Are there any paths that we should exclude? e.g. vendored files that we want to keep the same as their upstream copy?
• Do we want to break this down and apply it in chunks somehow?
• How should we time the merge of this change to reduce conflicts with open PRs?

[alliepiper]

Do we want to break this down and apply it in chunks somehow?

This might be a necessity, the changes view is crashing my browser 😄

Maybe 1 PR per project?

[wmaxey]

I'm under the impression we're going to want to exclude libcudacxx at least temporarily. We need to prevent clang-format from touching nv/target and probably figure out if we need a different format for the rest of the headers.

[jrhemstad]

I'm under the impression we're going to want to exclude libcudacxx at least temporarily. We need to prevent clang-format from touching nv/target and probably figure out if we need a different format for the rest of the headers.

We agreed in #551 to just have a single .clang-format for everything. I understand omitting nv/target, but everything else should be fair game.

[bdice]

Great, thanks for the feedback. I'll attempt to handle both comments above at the same time: I tweaked this and applied it only to CUB, to start. CUB has the smallest diff out of CUB, libcudacxx, and Thrust.

[wmaxey]

I'm under the impression we're going to want to exclude libcudacxx at least temporarily. We need to prevent clang-format from touching nv/target and probably figure out if we need a different format for the rest of the headers.

We agreed in #551 to just have a single .clang-format for everything. I understand omitting nv/target, but everything else should be fair game.

I'm happy with that. I looked at the changes and the surgery done isn't too impactful. <nv/target> was excluded already for some reason.

[bdice]

@jrhemstad @wmaxey @alliepiper I'm a little unsure of the conclusion to draw from the discussion above. Should I make a change and apply clang-format to the entire repo? Or break up the formatting into one PR per subproject as @alliepiper proposed?

[miscco]

I believe we should drop any additional .clang-format files.

<nv/target> can be dealt with a // clang-format off comment at the beginning of the file and // clang-format on at the end

It will be a trainwreck in our libcu++ test suite as we often have terribly long lines there, but I am absolutely in favor of just getting something in over the current state

[miscco]

I saw some issues with the formatting in libcu++ though.

It was not properly aligning consecutive alias definitions

[alliepiper]

I'm a little unsure of the conclusion to draw from the discussion above. Should I make a change and apply clang-format to the entire repo?

Making a separate PR for each subproject will simplify reviewing and let us discuss and deal with each one's issues separately, since some will probably be easier to land than others.

[alliepiper]

While we're at it, we should probably add something like this to track these big formatting sweeps: https://github.com/NVIDIA/nvbench/blob/main/.git-blame-ignore-revs

[bdice]

.git-blame-ignore-revs is a good idea, but it will have to be done in follow-up PRs because the commit hashes will not be known in advance due to squash merging.

[gevtushenko]

@bdice thank you for this effort! Setting up an auto-formatting was long overdue for CUB. I had a few minor fixes that I pushed to your branch.

[bdice]

@gevtushenko Awesome, thanks! Please merge when you’re ready. @miscco volunteered to do the follow-ups for enabling clang-format on Thrust and libcudacxx.

[miscco]

Thanks a lot for working on this @bdice its awesome 🎉