Add `unnecessary_to_owned` lint
This PR adds a lint to check for unnecessary calls to `ToOwned::to_owned` and other similar functions (e.g., `Cow::into_owned`, `ToString::to_string`, etc.).
The lint checks for expressions of the form `&receiver.to_owned_like()` used in a position requiring type `&T` where one of the following is true:
* `receiver`'s type is `T` exactly
* `receiver`'s type implements `Deref<Target = T>`
* `receiver`'s type implements `AsRef<T>`
The lint additionally checks for expressions of the form `receiver.to_owned_like()` used as arguments of type `impl AsRef<T>`.
It would be nice if the lint could also check for expressions used as arguments to functions like the following:
```
fn foo<T: AsRef<str>>(x: T) { ... }
```
However, I couldn't figure out how to determine whether a function input type was instantiated from a parameter with a trait bound.
If someone could offer me some guidance, I would be happy to add such functionality.
Closes#7933
changelog: Add [`unnecessary_to_owned`] lint
By changing `as_str()` to take `&self` instead of `self`, we can just
return `&str`. We're still lying about lifetimes, but it's a smaller lie
than before, where `SymbolStr` contained a (fake) `&'static str`!
Stabilize `iter::zip`
Hello all!
As the tracking issue (#83574) for `iter::zip` completed the final commenting period without any concerns being raised, I hereby submit this stabilization PR on the issue.
As the pull request that introduced the feature (#82917) states, the `iter::zip` function is a shorter way to zip two iterators. As it's generally a quality-of-life/ergonomic improvement, it has been integrated into the codebase without any trouble, and has been
used in many places across the rust compiler and standard library since March without any issues.
For more details, I would refer to `@cuviper's` original PR, or the [function's documentation](https://doc.rust-lang.org/std/iter/fn.zip.html).
Tweak errors coming from `for`-loop, `?` and `.await` desugaring
* Suggest removal of `.await` on non-`Future` expression
* Keep track of obligations introduced by desugaring
* Remove span pointing at method for obligation errors coming from desugaring
* Point at called local sync `fn` and suggest making it `async`
```
error[E0277]: `()` is not a future
--> $DIR/unnecessary-await.rs:9:10
|
LL | boo().await;
| -----^^^^^^ `()` is not a future
| |
| this call returns `()`
|
= help: the trait `Future` is not implemented for `()`
help: do not `.await` the expression
|
LL - boo().await;
LL + boo();
|
help: alternatively, consider making `fn boo` asynchronous
|
LL | async fn boo () {}
| +++++
```
Fix#66731.
Stabilize asm! and global_asm!
Tracking issue: #72016
It's been almost 2 years since the original [RFC](https://github.com/rust-lang/rfcs/pull/2850) was posted and we're finally ready to stabilize this feature!
The main changes in this PR are:
- Removing `asm!` and `global_asm!` from the prelude as per the decision in #87228.
- Stabilizing the `asm` and `global_asm` features.
- Removing the unstable book pages for `asm` and `global_asm`. The contents are moved to the [reference](https://github.com/rust-lang/reference/pull/1105) and [rust by example](https://github.com/rust-lang/rust-by-example/pull/1483).
- All links to these pages have been removed to satisfy the link checker. In a later PR these will be replaced with links to the reference or rust by example.
- Removing the automatic suggestion for using `llvm_asm!` instead of `asm!` if you're still using the old syntax, since it doesn't work anymore with `asm!` no longer being in the prelude. This only affects code that predates the old LLVM-style `asm!` being renamed to `llvm_asm!`.
- Updating `stdarch` and `compiler-builtins`.
- Updating all the tests.
r? `@joshtriplett`
fix clippy format using `cargo fmt -p clippy_{lints,utils}`
manually revert rustfmt line truncations
rename to hir::Let in clippy
Undo the shadowing of various `expr` variables after renaming `scrutinee`
reduce destructuring of hir::Let to avoid `expr` collisions
cargo fmt -p clippy_{lints,utils}
bless new clippy::author output
Update lintcheck output to use tables and add markdown support
This PR updates changes lintcheck's output to use text tables and adds a markdown option to use Markdown links in the reports table. At first, I tried to keep the original output format, but the loading of old stats broke with the markdown option. The old format is therefore sadly incompatible with the new one. I can if requested make it in a way that the markdown output is only and optional additional output, but that would require more work for little benefit IMO.
For now, lintcheck has two output types. Here are the examples (best viewed on desktop):
<details>
<summary>`cargo lintcheck --only anyhow`</summary>
```txt
clippy 0.1.59 (460bef22a 2021-12-08)
### Reports
target/lintcheck/sources/anyhow-1.0.38/build.rs:1:null clippy::cargo_common_metadata "package `anyhow` is missing `package.keywords` metadata"
target/lintcheck/sources/anyhow-1.0.38/src/error.rs:350:5 clippy::missing_panics_doc "docs for function which may panic missing `# Panics` section"
target/lintcheck/sources/anyhow-1.0.38/src/lib.rs:1:null clippy::cargo_common_metadata "package `anyhow` is missing `package.keywords` metadata"
### Stats:
| lint | count |
| -------------------------------------------------- | ----- |
| clippy::missing_panics_doc | 1 |
| clippy::cargo_common_metadata | 2 |
### ICEs:
```
</details>
<details>
<summary>`cargo lintcheck --only anyhow --markdown` (The file links only work locally)</summary>
clippy 0.1.59 (460bef22a 2021-12-08)
### Reports
| file | lint | message |
| --- | --- | --- |
| [`anyhow-1.0.38/build.rs:1:null`](../target/lintcheck/sources/anyhow-1.0.38/build.rs#L1) | `clippy::cargo_common_metadata` | "package `anyhow` is missing `package.keywords` metadata" |
| [`anyhow-1.0.38/src/error.rs:350:5`](../target/lintcheck/sources/anyhow-1.0.38/src/error.rs#L350) | `clippy::missing_panics_doc` | "docs for function which may panic missing `# Panics` section" |
| [`anyhow-1.0.38/src/lib.rs:1:null`](../target/lintcheck/sources/anyhow-1.0.38/src/lib.rs#L1) | `clippy::cargo_common_metadata` | "package `anyhow` is missing `package.keywords` metadata" |
### Stats:
| lint | count |
| -------------------------------------------------- | ----- |
| clippy::missing_panics_doc | 1 |
| clippy::cargo_common_metadata | 2 |
### ICEs:
</details>
The table margins are so large to keep the table inline for long file names and lint names
---
changelog: none
r? `@matthiaskrgr`
Remove lintcheck log and add `--filter` option to lintcheck
This PR removes the really outdated lintcheck log from this repo and adds a new `--filter` option to force warnings of a lint. This also ignores `allow` attributes. I believe that this is a good thing, as we'll see if suppressed false positives are also fixed by the changes.
---
#### Example:
```sh
$ cargo lintcheck --filter identity_op
```
#### Output
```
clippy 0.1.59 (460bef22a 2021-12-08)
[..]/cargo-0.49.0/src/cargo/core/compiler/fingerprint.rs:1910:17 clippy::identity_op "the operation is ineffective. Consider reducing it to `(ret[0] as usize)`"
[..]/cargo-0.49.0/src/cargo/util/hex.rs:8:9 clippy::identity_op "the operation is ineffective. Consider reducing it to `num`"
[..]/libc-0.2.81/src/unix/linux_like/linux/mod.rs:2654:18 clippy::identity_op "the operation is ineffective. Consider reducing it to `(dev & 0x00000000000000ff)`"
[..]/libc-0.2.81/src/unix/linux_like/linux/mod.rs:2665:16 clippy::identity_op "the operation is ineffective. Consider reducing it to `(minor & 0x000000ff)`"
[..]/libc-0.2.81/src/unix/linux_like/mod.rs:1218:27 clippy::identity_op "the operation is ineffective. Consider reducing it to `IPOPT_CONTROL`"
[..]/rayon-1.5.0/src/slice/quicksort.rs:588:17 clippy::identity_op "the operation is ineffective. Consider reducing it to `len / 4`"
[..]/regex-1.3.2/src/dfa.rs:1380:14 clippy::identity_op "the operation is ineffective. Consider reducing it to `(empty_flags.start as u8)`"
Stats:
clippy::identity_op 7
ICEs:
```
Two of these lints are suppressed when lintcheck runs normally
---
changelog: none
r? `@matthiaskrgr` Feel free to reassign if you think that someone else would be a better reviewer 🙃
Add new lint to warn when #[must_use] attribute should be used on a method
This lint is somewhat similar to https://rust-lang.github.io/rust-clippy/master/index.html#must_use_candidate but also different: it emits a warning by default and only targets methods (so not functions nor associated functions).
Someone suggested it to me after this tweet: https://twitter.com/m_ou_se/status/1466439813230477312
I think it would reduce the number of cases of API misuses quite a lot.
What do you think?
---
changelog: Added new [`return_self_not_must_use`] lint
Ignore associated types in traits when considering type complexity
changelog: Ignore associated types in traits when checking ``[`type_complexity`]`` lint.
fixes#1013
