Improve `needless_lifetimes`
This PR makes the following improvements to `needless_lifetimes`.
* It fixes the following false negative, where `foo` is flagged but `bar` is not:
```rust
fn foo<'a>(x: &'a u8, y: &'_ u8) {}
fn bar<'a>(x: &'a u8, y: &'_ u8, z: &'_ u8) {}
```
* It flags more cases, generally. Previously, `needless_borrow` required *all* lifetimes to be used only once. With the changes, individual lifetimes are flagged for being used only once, even if not all lifetimes are.
* Finally, it tries to produce more clear error messages.
changelog: fix `needless_lifetimes` false negative involving functions with multiple unnamed lifetimes
changelog: in `needless_lifetimes`, flag individual lifetimes used only once, rather than require all lifetimes to be used only once
changelog: in `needless_lifetimes`, emit "replace with `'_`" warnings only when applicable, and point to a generic argument
make ignored internally mutable types for `mutable-key` configurable
We had some false positives where people would create their own types that had interior mutability unrelated to hash/eq. This addition lets you configure this as e.g. `arc-like-types=["bytes::Bytes"]`
This fixes#5325 by allowing users to specify the types whose innards like `Arc` should be ignored (the generic types are still checked) for the sake of detecting inner mutability.
r? `@Alexendoo`
---
changelog: Allow configuring types to ignore internal mutability in `mutable-key`
add new lint `seek_to_start_instead_of_rewind `
changelog: `seek_to_start_instead_of_rewind`: new lint to suggest using `rewind` instead of `seek` to start
Resolve#8600
We had some false positives where people would create their own types
that had interior mutability unrelated to hash/eq. This addition lets
you configure this as e.g. `arc-like-types=["bytes::Bytes"]`
Fix bug introduced by #9386#9386 introduced a potential out-of-bounds array access. Specifically, a location returned by `local_assignments` could have [`location.statement_index` equal to `mir.basic_blocks[location.block].statements.len()`](b8a9a507bf/clippy_utils/src/mir/mod.rs (L129)), in which case the location would refer to the block terminator:
b8a9a507bf/clippy_lints/src/dereference.rs (L1204-L1206)
I suspect the bug is not triggerable now, because of checks leading up to where it occurs. But a future code change could make it triggerable. Hence, it should be fixed.
r? `@Jarcho`
changelog: none
Add `unused_format_specs` lint
Currently catches two cases:
An empty precision specifier:
```rust
// the same as {}
println!("{:.}", x);
```
And using formatting specs on `format_args!()`:
```rust
// prints `x.`, not `x .`
println("{:5}.", format_args!("x"));
```
changelog: new lint: [`unused_format_specs`]
[`unnecessary_cast`] Do not lint negative hexadecimal literals when cast as floats
fix https://github.com/rust-lang/rust-clippy/issues/9603
changelog: [`unnecessary_cast`] Do not lint negative hexadecimal literals when cast as floats
Don't suggest moving tuple structs with a significant drop to late evaluation
fixes#9608
changelog: Don't suggest moving tuple structs with a significant drop to late evaluation
rename `ImplItemKind::TyAlias` to `ImplItemKind::Type`
The naming of this variant seems inconsistent given that this is not really a "type alias", and the associated type variant for `TraitItemKind` is just called `Type`.
Further enhance `needless_borrow`, mildly refactor `redundant_clone`
This PR does the following:
* Moves some code from `redundant_clone` into a new `clippy_utils` module called `mir`, and wraps that code in a function called `dropped_without_further_use`.
* Relaxes the "is copyable" condition condition from #9136 by also suggesting to remove borrows from values dropped without further use. The changes involve the just mentioned function.
* Separates `redundant_clone` into modules.
Strictly speaking, the last bullet is independent of the others. `redundant_clone` is somewhat hairy, IMO. Separating it into modules makes it slightly less so, by helping to delineate what depends upon what.
I've tried to break everything up into digestible commits.
r? `@Jarcho`
(`@Jarcho` I hope you don't mind.)
changelog: continuation of #9136
Add `manual_filter` lint for `Option`
Share much of its implementation with `manual_map` and should greatly benefit from its previous feedback.
I'm sure it's possible to even more refactor both and would gladly take input on that as well as any clippy idiomatic usage, since this is my first lint addition.
I've added the lint to the complexity section for now, I don't know if every new lint needs to go in nursery first.
The matching could be expanded to more than `Some(<value>)` to lint on arbitrary struct matching inside the `Some` but I've left it like it was for `manual_map` for now. `needless_match::pat_same_as_expr` provides a more generic match example.
close https://github.com/rust-lang/rust-clippy/issues/8822
changelog: Add lint [`manual_filter`] for `Option`
Remove `mir::CastKind::Misc`
As discussed in #97649 `mir::CastKind::Misc` is not clear, this PR addresses that by creating a new enum variant for every valid cast.
r? ````@oli-obk````
extend `box-default` lint, add suggestion
This extends the recently added `box-default` lint to also cover `Box::new(vec![])`, `Box::new(String::from(""))` and `Box::new(Vec::from([]))`. Also the lint now suggests a suitable replacement. I did not find a simple way to check whether the type is fully determined by the outside, so I at least checked for some variations to remove the turbofish in those cases.
---
changelog: none
FormatArgsExpn: Find comma spans and ignore weird proc macro spans
Fixes the following cases:
A missing `, 1` from the `expect_fun_call` suggestion:
```rust
Some(()).expect(&format!("{x} {}", 1));
```
```
warning: use of `expect` followed by a function call
--> t.rs:7:14
|
7 | Some(()).expect(&format!("{x} {}", 1));
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|| panic!("{x} {}"))`
```
The suggestion removing from the comma in the comment rather than the one after the format string:
```rust
println!(
"{}",
// a comment, with a comma in it
x
);
```
```
warning: variables can be used directly in the `format!` string
--> t.rs:9:5
|
9 | / println!(
10 | | "{}",
11 | | // a comment, with a comma in it
12 | | x
13 | | );
| |_____^
|
help: change this to
|
10 ~ "{x}",
11 ~ // a comment
|
```
It also no longer accepts expansions where a format string or argument has a "weird" proc macro span, that is one where the literal/expression it outputs has the span of one of its inputs. Kind of like a `format_args` specific `clippy_utils::is_from_proc_macro`, e.g. `format!(indoc! {" ... "})`
changelog: [`expect_fun_call`]: Fix suggestion for `format!` using captured variables
changelog: [`print_literal`], [`write_literal`], [`uninlined_format_args`]: Fix suggestion when following a comment including a comma
* Check for `const`s and `static`s from external crates
* Check for `LangItem`s
* Handle inherent functions which have the same name as a field
* Also check the following functions:
* `match_trait_method`
* `match_def_path`
* `is_expr_path_def_path`
* `is_qpath_def_path`
* Handle checking for a constructor to a diagnostic item or `LangItem`
