feat(lint): impl lint about use first() instead of get(0)
close#8851
This PR adds new lint about considering replacing .get(0) with .first().
Thank you in advance.
changelog: adds new lint [`get_first`] to consider replacing .get(0) with .first()
`get_last_with_len`: lint `VecDeque` and any deref to slice
changelog: [`get_last_with_len`]: lint `VecDeque` and any deref to slice
Previously only `Vec`s were linted, this will now catch any usages on slices, arrays, etc. It also suggests `.back()` for `VecDeque`s
Also moves the lint into `methods/`
Add some testcases for recent rustfix update
changelog: none
This adds a testcase for a bugfix that has been fixed by https://github.com/rust-lang/rustfix/tree/v0.6.1
`rustfix` is pulled in by `compiletest_rs`. So to test that the correct rustfix version is used, I added one (and a half) testcase.
I tried to add a testcase for #8734 as well, but interesting enough the rustfix is wrong:
```diff
fn issue8734() {
let _ = [0u8, 1, 2, 3]
.into_iter()
- .and_then(|n| match n {
+ .flat_map(|n| match n {
+ 1 => [n
+ .saturating_add(1)
1 => [n
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)
.saturating_add(1)],
n => [n],
});
}
```
this needs some investigation and then this testcase needs to be enabled by commenting it out
closes#8878
related to #8734
`identity_op`: add parenthesis to suggestions where required
changelog: [`identity_op`]: add parenthesis to suggestions where required
Follow up to #8730, wraps the cases we can't lint as-is in parenthesis rather than ignoring them
Catches a couple new FPs with mixed operator precedences and `as` casts
```rust
// such as
0 + { a } * 2;
0 + a as usize;
```
The suggestions are now applied using `span_lint_and_sugg` rather than appearing in just the message and have a `run-rustfix` test
Fix imports for "Checking if a type defines a specific method"
The import of `clippy_utils::is_type_diagnostic_item` would cause this error:
```
error[E0432]: unresolved import `clippy_utils::is_type_diagnostic_item
```
changelog: none
The import of `clippy_utils::is_type_diagnostic_item` would cause this
error:
```
error[E0432]: unresolved import `clippy_utils::is_type_diagnostic_item
```
Refactor call terminator to always include destination place
In #71117 people seemed to agree that call terminators should always have a destination place, even if the call was guaranteed to diverge. This implements that. Unsurprisingly, the diff touches a lot of code, but thankfully I had to do almost nothing interesting. The only interesting thing came up in const prop, where the stack frame having no return place was also used to indicate that the layout could not be computed (or similar). I replaced this with a ZST allocation, which should continue to do the right things.
cc `@RalfJung` `@eddyb` who were involved in the original conversation
r? rust-lang/mir-opt
Lifetime variance fixes for clippy
#97287 migrates rustc to a `Ty` type that is invariant over its lifetime `'tcx`, so I need to fix a bunch of places that assume that `Ty<'a>` and `Ty<'b>` can be shortened to some common lifetime.
This is doable, since everything is already `'tcx`, so all this PR does is be a bit more explicit that elided lifetimes are actually `'tcx`.
Split out from #97287 so the clippy team can review independently.
Drop Tracking: Implement `fake_read` callback
This PR updates drop tracking's use of `ExprUseVisitor` so that we treat `fake_read` events as borrows. Without doing this, we were not handling match expressions correctly, which showed up as a breakage in the `addassign-yield.rs` test. We did not previously notice this because we still had rather large temporary scopes that we held borrows for, which changed in #94309.
This PR also includes a variant of the `addassign-yield.rs` test case to make sure we continue to have correct behavior here with drop tracking.
r? `@nikomatsakis`
Rustup
`@rust-lang/clippy,` `@Jarcho,` `@dswij,` `@Alexendoo.` Could someone review this? It should be pretty straight forward since it's just a sync. I think it's also fine if either one of `@Jarcho,` `@dswij,` `@Alexendoo` approves this, as these are usually not reviewed. I just want to make sure that I didn't break something obvious 🙃
It should be enough to look at the merge commit 🙃
changelog: none
changelog: move [`significant_drop_in_scrutinee`] to `suspicious`
