Rework use_self impl based on ty::Ty comparison #3410 | Take 2
This builds on top of #5531
I already reviewed and approved the commits by `@montrivo.` So only the review of my commits should be necessary.
I would also appreciate your review `@montrivo,` since you are familiar with the challenges here.
Fixes#3410 and Fixes#4143 (same problem)
Fixes#2843Fixes#3859Fixes#4734 and fixes#6221Fixes#4305Fixes#5078 (even at expression level now 🎉)
Fixes#3881 and Fixes#4887 (same problem)
Fixes#3909
Not yet: #4140 (test added)
All the credit for the fixes goes to `@montrivo.` I only refactored and copy and pasted his code.
changelog: rewrite [`use_self`] lint and fix multiple (8) FPs. One to go.
Fix suggestions that need parens in `from_iter_instead_of_collect` lint
Fixes broken suggestions that need parens (i.e.: range)
Fixes: #6648
changelog: none
This renames the variants in HIR UnOp from
enum UnOp {
UnDeref,
UnNot,
UnNeg,
}
to
enum UnOp {
Deref,
Not,
Neg,
}
Motivations:
- This is more consistent with the rest of the code base where most enum
variants don't have a prefix.
- These variants are never used without the `UnOp` prefix so the extra
`Un` prefix doesn't help with readability. E.g. we don't have any
`UnDeref`s in the code, we only have `UnOp::UnDeref`.
- MIR `UnOp` type variants don't have a prefix so this is more
consistent with MIR types.
- "un" prefix reads like "inverse" or "reverse", so as a beginner in
rustc code base when I see "UnDeref" what comes to my mind is
something like "&*" instead of just "*".
Add new lint `filter_map_identity`
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This commit adds a new lint named filter_map_identity.
This lint is the same as `flat_map_identity` except that it checks for the usage of `filter_map`.
---
Closes#6643
changelog: Added a new lint: `filter_map_identity`
Adds a new lint that checks if there is a semicolon on the last block statement if it returns nothing
changelog: Added a new lint: `SEMICOLON_IF_NOTHING_RETURNED`
fixes#6467
Adds the `SEMICOLON_IF_NOTHING_RETURNED` lint and therefore closes#6467.
This commit adds a new lint named `filter_map_identity`. This lint is
the same as `flat_map_identity` except that it checks for `filter_map`.
Closes#6643
New Lint: Manual Flatten
This is a draft PR for [Issue 6564](https://github.com/rust-lang/rust-clippy/issues/6564).
r? `@camsteffen`
- \[x] Followed [lint naming conventions][lint_naming]
- \[x] Added passing UI tests (including committed `.stderr` file)
- \[x] `cargo test` passes locally
- \[x] Executed `cargo dev update_lints`
- \[x] Added lint documentation
- \[x] Run `cargo dev fmt`
---
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Add new lint [`manual_flatten`] to check for loops over a single `if let` expression with `Result` or `Option`.
Fix file names of flat_map_identity test
This patch fixes the file names of the `flat_map_identity` test.
Previously, their names were started with `unnecessary_flat_map` even though the lint rule name is `flat_map_identity`. This inconsistency happened probably because the rule name was changed during the discussion in the PR where this rule was introduced.
ref: https://github.com/rust-lang/rust-clippy/pull/4231
changelog: none
This commit fixes the file names of the `flat_map_identity` test.
Previously, their names were started with `unnecessary_flat_map` even
though the lint rule name is `flat_map_identity`. This inconsistency
happened probably because the rule name was changed during the
discussion in the PR where this rule was introduced.
ref: https://github.com/rust-lang/rust-clippy/pull/4231
Fix let_and_return false positive
The issue:
See this Rust playground link: https://play.rust-lang.org/?edition=2018&gist=12cb5d1e7527f8c37743b87fc4a53748
Run the above with clippy to see the following warning:
```
warning: returning the result of a `let` binding from a block
--> src/main.rs:24:5
|
23 | let value = Foo::new(&x).value();
| --------------------------------- unnecessary `let` binding
24 | value
| ^^^^^
|
= note: `#[warn(clippy::let_and_return)]` on by default
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
help: return the expression directly
|
23 |
24 | Foo::new(&x).value()
|
```
Implementing the suggested fix, removing the temporary let binding,
yields a compiler error:
```
error[E0597]: `x` does not live long enough
--> src/main.rs:23:14
|
23 | Foo::new(&x).value()
| ---------^^-
| | |
| | borrowed value does not live long enough
| a temporary with access to the borrow is created here ...
24 | }
| -
| |
| `x` dropped here while still borrowed
| ... and the borrow might be used here, when that temporary is dropped and runs the `Drop` code for type `Foo`
|
= note: the temporary is part of an expression at the end of a block;
consider forcing this temporary to be dropped sooner, before the block's local variables are dropped
help: for example, you could save the expression's value in a new local variable `x` and then make `x` be the expression at the end of the block
|
23 | let x = Foo::new(&x).value(); x
| ^^^^^^^ ^^^
```
The fix:
Of course, clippy looks like it should already handle this edge case;
however, it appears `utils::fn_def_id` is not returning a `DefId` for
`Foo::new`. Changing the `qpath_res` lookup to use the child Path
`hir_id` instead of the parent Call `hir_id` fixes the issue.
changelog: none
