Update lint deprecation for tool lints

[phansch]

changelog: Allow tool lints (clippy::*) to be deprecated

Our lint deprecation previously didn't work for tool lints, because
register_removed was registering lints to be removed without the
clippy prefix.

Fixes #4349

[phansch]

Note that the current change means, that this will stop deprecation warnings when using non-tool lints, like #[allow(assign_ops)]. There will just be an unknown_lint warning for non-tool lints.

cc @flip1995

[flip1995]

Note that the current change means, that this will stop deprecation warnings when using non-tool lints

When I implemented the tool lints, I was aware of this problem, but decided to leave it untouched until we heave to deprecate another lint. The reasoning behind that was, that people who still use the deprecated lints, probably won't use tool lints. That reasoning still applies, so the best case would be to allow deprecating both tool lints and non-tool lints. But IIRC that wasn't that easy to implement (otherwise I would have done it (probably 😄)).

I think every maintained crate swapped to tool lints by now and we're on the safe side to make this change?

[phansch]

allow deprecating both tool lints and non-tool lints.

I haven't tried it, but wouldn't it be enough to register both the tool version and the non-tool version as removed (on the Clippy side)?

[flip1995]

There will just be an unknown_lint warning for non-tool lints.

This warning is not optimal, but I think as long as there is some warning about deprecated lints, this should be fine.

[flip1995]

"specialization will likely happen soon" 15e55f5 lol 😄

[flip1995]

I haven't tried it, but wouldn't it be enough to register both the tool version and the non-tool version as removed (on the Clippy side)?

We can try it. But that should only be required for lints that were deprecated before tool lints existed. So I would place them in a separate function or write a deprecate_old! macro to do this.

[phansch]

@flip1995 should be good to go now
edit: oops, need to fix a method call first

[flip1995]

Thanks!

@bors r+

[bors]

📌 Commit e406ab5 has been approved by flip1995

[bors]

⌛ Testing commit e406ab5 with merge d37233c...

[bors]

💔 Test failed - checks-travis

[matthiaskrgr]

Looks spurious?

   Compiling cargo_metadata v0.8.1

   Compiling clippy_lints v0.0.212 (C:\Users\travis\build\rust-lang\rust-clippy\clippy_lints)

    Finished dev [unoptimized + debuginfo] target(s) in 4m 27s

+++ cargo test --features 'debugging deny-warnings'

error: unable to unlink old fallback exe

info: caused by: Access is denied. (os error 5)

info: backtrace:

stack backtrace:

   0: <no info> (0x72aa68)

   1: <no info> (0x72aeca)

   2: <no info> (0x7275db)

   3: <no info> (0x5511eb)

   4: <no info> (0x5b9049)

   5: <no info> (0x470d5c)

   6: <no info> (0x46d302)

   7: <no info> (0x407bb6)

   8: <no info> (0x473032)

   9: <no info> (0x4013f8)

  10: <no info> (0x40151b)

  11: BaseThreadInitThunk (0x7ffcc8f03034)

@bors retry

[phansch]

@bors retry yup!

[bors]

⌛ Testing commit e406ab5 with merge 06430e7...

[bors]

☀️ Test successful - checks-travis, status-appveyor
Approved by: flip1995
Pushing 06430e7 to master...