Add `unnecessary_find_map` lint
This PR adds an `unnecessary_find_map` lint. It is essentially just a minor enhancement of `unnecessary_filter_map`.
Closes#8467
changelog: New lint `unnecessary_find_map`
new lint: `missing-spin-loop`
This fixes#7809. I went with the shorter name because the function is called `std::hint::spin_loop`. It doesn't yet detect `while let` loops. I left that for a follow-up PR.
---
changelog: new lint: [`missing_spin_loop`]
Transmute_undefined_repr to nursery again
This PR reinstates #8418, which was reverted in #8425 (incorrectly I think).
I don't want to start a revert war over this but I feel very strongly that this lint is not in a state that would be a net benefit to users of clippy. In its current form, making this an enabled-by-default `correctness` lint with authoritative-sounding proclamations of undefined behavior does more harm than the benefit of the true positive cases.
I can file a bunch more examples of false positives but I don't want to give the author of this lint the impression that it is ready to graduate from `nursery` as soon as I've exhausted the amount of time I am willing to spend revising this lint.
Instead I would recommend that the author of the lint try running it on some reputable codebases containing transmutes. Everywhere that the lint triggers please consider critically whether it should be triggering. For cases that you think are true positives, please raise a few of them with the crate authors (in a PR or issue) to better understand their perspective if they think the transmute is correct.
---
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Re-remove [`transmute_undefined_repr`] from default set of enabled lints
This internal lint checks if the `extract_msrv_attrs!` macro is used if
a lint has a MSRV. If not, it suggests to add this attribute to the lint
pass implementation.
fix false positives of large_enum_variant
fixes: #8321
The size of enums containing generic type was calculated to be 0.
I changed [large_enum_variant] so that such enums are not linted.
changelog: none
Don't lint `match` expressions with `cfg`ed arms
Somehow there are no open issues related to this for any of the affected lints. At least none that I could fine from a quick search.
changelog: Don't lint `match` expressions with `cfg`ed arms in many cases
Fix `await_holding_lock` not linting `parking_lot` Mutex/RwLock
This adds tests for `RwLock` and `parking_lot::{Mutex, RwLock}`, which were added before in 2dc8c083f5, but never tested in UI tests. I noticed this while reading [fasterthanli.me](https://fasterthanli.me/articles/a-rust-match-made-in-hell) latest blog post, complaining that Clippy doesn't catch this for `parking_lot`. (Too many people read his blog, he's too powerful)
Some more things:
- Adds a test for #6446
- Improves the lint message
changelog: [`await_holding_lock`]: Now also lints for `parking_lot::{Mutex, RwLock}`
Even though the FP for that the lints were moved to pedantic isn't fixed
yet, running the lintcheck tool over the most popular 279 crates didn't
trigger this lint once. I would say that this lint is valuable enough,
despite the known FP, to be warn-by-default. Especially since a pretty
nice workaround exists.
Improve `redundant_slicing` lint
fixes#7972fixes#7257
This can supersede #7976
changelog: Fix suggestion for `redundant_slicing` when re-borrowing for a method call
changelog: New lint `deref_as_slicing`
Don't lint `needless_borrow` in method receiver positions
fixes#8408fixes#8407fixes#8391fixes#8367fixes#8380
This is a temporary fix for `needless_borrow`. The proper fix is included in #8355.
This should probably be merged into rustc before beta branches on Friday. This issue has been reported six or seven times in the past couple of weeks.
changelog: Fix various issues with `needless_borrow` n´. Note to changelog writer: those issues might have been introduced in this release cycle, so this might not matter in the changelog.
Don't lint Default::default if it is the udpate syntax base
changelog: Don't lint `Default::default` it is part of the update syntax
Current clippy warns about this:
```
warning: calling `Foo::default()` is more clear than this expression
--> src/main.rs:12:11
|
12 | ..Default::default()
| ^^^^^^^^^^^^^^^^^^ help: try: `Foo::default()`
|
```
With these changes, it will not lint that particular expression anymore.
