fix: Make rust-analyzer.files.excludeDirs work, actually

[ChayimFriedman2]

I have no idea what the original writer of the code thought (CC @matklad, I don't expect you to remember but it was you), but the logic just seems backwards. We should not exclude a file/directory if it is equal to an include! This also meant that we had to add a root == path check so this stuff will actually work, which in turn meant excludes (of root files) no longer worked...

Also rename if to rust-analyzer.files.exclude, because it can exclude files as well.

Fixes #14734.

[matklad]

The original logic still looks correct to me!

It handles nested entries. If root B is nested under A, and C is excluded, then, while scanning A:

• you should ignore C as it is explicitly excluded
• But you also should ignore B, as you get to scanning the contents of B separately

That is, there’s an outer loop over A and B anyway. Without this exclusion, B will be scanned twice

[ChayimFriedman2]

Okay, so the logic needs to be:

dirs.exclude.iter().all(|it| it != path) && (root == path || dirs.include.iter().all(|it| it != path))

[matklad]

To make sure I understand correctly, what happens here is that the same path ends up in exclude (explicitly configured by the user) and also in the include (I am guessing through auto-discovery mechanism)?

🤔

Should be perhaps push the if up here? In VFS, we can assert that neither path is simultaneously in the inclusion and exclusion list.

In the project-discovery code, we can explicitly exclude the excluded directories.

---

Unrelated, but, due to a bug in GitHub, it is best not to include @-mentions in the commit messages. GitHub incorrectly sends a email-notification every time such a commit is pushed, including rebases and forks.

Pings in PR descriptions are totally fine and encouraged!

[ChayimFriedman2]

To make sure I understand correctly, what happens here is that the same path ends up in exclude (explicitly configured by the user) and also in the include (I am guessing through auto-discovery mechanism)?

Yes, exactly.

Should be perhaps push the if up here? In VFS, we can assert that neither path is simultaneously in the inclusion and exclusion list.

I don't think, I think it's fine as it's now.

Unrelated, but, due to a bug in GitHub, it is best not to include @-mentions in the commit messages. GitHub incorrectly sends a email-notification every time such a commit is pushed, including rebases and forks.

Didn't know, sorry! I edited the commit message.

[ChayimFriedman2]

Okay this is now ready for review.

[Veykril]

Unfortunate that we have to encode this specially in the VFS (and then effectively handle in every request handler), but it does make sense as to why (and I can't think of a different way to do this either)

[futile]

Ping, kind of waiting for this (I think it'll solve my "Roots scanned" issue), and wanted to ask when it can/will be merged? thanks! :)

[Veykril]

Forgot about this, should be good to merge :)

[futile]

Awesome, thank you! 🚀