I want to be clear: this is just the initial draft outlining what, I think, should be the responsibilities of the team members. It has not yet been discussed with anyone else.
Add `assigning_clones` lint
This PR is a "revival" of https://github.com/rust-lang/rust-clippy/pull/10613 (with `@kpreid's` permission).
I tried to resolve most of the unresolved things from the mentioned PR:
1) The lint now checks properly if we indeed call the functions `std::clone::Clone::clone` or `std::borrow::ToOwned::to_owned`.
2) It now supports both method and function (UFCS) calls.
3) A heuristic has been added to decide if the lint should apply. It will only apply if the type on which the method is called has a custom implementation of `clone_from/clone_into`. Notably, it will not trigger for types that use `#[derive(Clone)]`.
4) `Deref` handling has been (hopefully) a bit improved, but I'm not sure if it's ideal yet.
I also added a bunch of additional tests.
There are a few things that could be improved, but shouldn't be blockers:
1) When the right-hand side is a function call, it is transformed into e.g. `::std::clone::Clone::clone(...)`. It would be nice to either auto-import the `Clone` trait or use the original path and modify it (e.g. `clone::Clone::clone` -> `clone::Clone::clone_from`). I don't know how to modify the `QPath` to do that though.
2) The lint currently does not trigger when the left-hand side is a local variable without an initializer. This is overly conservative, since it could trigger when the variable has no initializer, but it has been already initialized at the moment of the function call, e.g.
```rust
let mut a;
...
a = Foo;
...
a = b.clone(); // Here the lint should trigger, but currently doesn't
```
These cases probably won't be super common, but it would be nice to make the lint more precise. I'm not sure how to do that though, I'd need access to some dataflow analytics or something like that.
changelog: new lint [`assigning_clones`]
[`misrefactored_assign_op`]: Fix duplicate diagnostics
Relate to #12379
The following diagnostics appear twice
```
--> tests/ui/assign_ops2.rs:26:5
|
LL | a *= a * a;
| ^^^^^^^^^^
|
help: did you mean `a = a * a` or `a = a * a * a`? Consider replacing it with
```
because `a` (lhs) appears in both left operand and right operand in the right hand side.
This PR fixes the issue so that if a diagnostic is created for an operand, the check of the other operand will be skipped. It's fine because the result is always the same in the affected operators.
changelog: [`misrefactored_assign_op`]: Fix duplicate diagnostics
Don't emit "missing backticks" lint if the element is wrapped in `<code>` HTML tags
Fixes#9473.
changelog: Don't emit "missing backticks" lint if the element is wrapped in `<code>` HTML tags
Handle plural acronyms in `doc_markdown`
Prevent `doc_markdown` from triggering on words like `OSes` and `UXes`.
changelog: handle plural acronyms in `doc_markdown`
Add documentation on trait checking and type construction
Changes:
Added documentation on how to create types via `Ty` and how to check specific trait implementations.
changelog: none
r? `@blyxyas`
Add missing header for `manual_is_variant_and`
Noticed this while generating our lint completions failed in rust-analyzer (separate PR from https://github.com/rust-lang/rust-clippy/pull/12415 as I made these via the github interface quickly)
changelog: none
[`identity_op`]: Fix duplicate diagnostics
Relates to #12379
In the `identity_op` lint, the following diagnostic was emitted two times
```
--> tests/ui/identity_op.rs:156:5
|
LL | 1 * 1;
| ^^^^^ help: consider reducing it to: `1`
|
```
because both of the left operand and the right operand are the identity element of the multiplication.
This PR fixes the issue so that if a diagnostic is created for an operand, the check of the other operand will be skipped. It's fine because the result is always the same in the affected operators.
---
changelog: [`identity_op`]: Fix duplicate diagnostics
Check for try blocks in `question_mark` more consistently
Fixes#12337
I split this PR up into two commits since this moves a method out of an `impl`, which makes for a pretty bad diff (the `&self` parameter is now unused, and there isn't a reason for that function to be part of the `impl` now).
The first commit is the actual relevant change and the 2nd commit just moves stuff (github's "hide whitespace" makes the diff easier to look at)
------------
Now for the actual issue:
`?` within `try {}` blocks desugars to a `break` to the block, rather than a `return`, so that changes behavior in those cases.
The lint has multiple patterns to look for and in *some* of them it already does correctly check whether we're in a try block, but this isn't done for all of its patterns.
We could add another `self.inside_try_block()` check to the function that looks for `let-else-return`, but I chose to actually just move those checks out and instead have them in `LintPass::check_{stmt,expr}`. This has the advantage that we can't (easily) accidentally forget to add that check in new patterns that might be added in the future.
(There's also a bit of a subtle interaction between two lints, where `question_mark`'s LintPass calls into `manual_let_else`, so I added a check to make sure we don't avoid linting for something that doesn't have anything to do with `?`)
changelog: [`question_mark`]: avoid linting on try blocks in more cases
fix [`derive_partial_eq_without_eq`] FP on trait projection
fixes: #9413#9319
---
changelog: fix [`derive_partial_eq_without_eq`] FP on trait projection
Well, this is awkward, it works but I don't understand why, why `clippy_utils::ty::implements_trait` couldn't detects the existance of `Eq` trait, even thought it's obviously present in the derive attribute.
Pointers cannot be converted to integers at compile time
Fix#12402
changelog: [`transmutes_expressible_as_ptr_casts`]: do not suggest invalid const casts
Dedup std_instead_of_core by using first segment span for uniqueness
Relates to #12379.
Instead of checking that the paths have an identical span, it checks that the relevant `std` part of the path segment's span is identical. Added a multiline test, because my first implementation was worse and failed that, then I realized that you could grab the span off the first_segment `Ident`.
I did find another bug that isn't addressed by this, and that exists on master as well.
The path:
```Rust
use std::{io::Write, fmt::Display};
```
Will get fixed into:
```Rust
use core::{io::Write, fmt::Display};
```
Which doesn't compile since `io::Write` isn't in `core`, if any of those paths are present in `core` it'll do the replace and cause a miscompilation. Do you think I should file a separate bug for that? Since `rustfmt` default splits those up it isn't that big of a deal.
Rustfmt:
```Rust
// Pre
use std::{io::Write, fmt::Display};
// Post
use std::fmt::Display;
use std::io::Write;
```
---
changelog: [`std_instead_of_core`]: Fix duplicated output on multiple imports
Document manifest options
All built-in cargo commands have this output included when run with `cargo foo --help`. Clippy is the only exception, so I have copied the text here. As far as I can tell, the flags come from Cargo itself and not clippy, but the user almost certainly does not care about that.
```text
Manifest Options:
--manifest-path <PATH> Path to Cargo.toml
--frozen Require Cargo.lock and cache are up to date
--locked Require Cargo.lock is up to date
--offline Run without accessing the network
```
changelog: Add the standard Manifest Options section to the `--help` output
fix: `manual_memcpy` wrong indexing for multi dimensional arrays
fixes: #9334
This PR fixes an invalid suggestion for multi-dimensional arrays.
For example,
```rust
let src = vec![vec![0; 5]; 5];
let mut dst = vec![0; 5];
for i in 0..5 {
dst[i] = src[i][i];
}
```
For the above code, Clippy suggests `dst.copy_from_slice(&src[i]);`, but it is not compilable because `i` is only used to loop the array.
I adjusted it so that Clippy `manual_memcpy` works properly for multi-dimensional arrays.
changelog: [`manual_memcpy`]: Fixes invalid indexing suggestions for multi-dimensional arrays
Fix FP in `threadlocal!` when falling back to `os_local`
**Issue**: The lint always triggers for some targets.
**Why**: The lint assumes an `__init` function is not present for const initializers.
This does not hold for all targets. Some targets always have an initializer function.
**Fix**: If an initializer function exists, we check that it is not a `const` fn.
Lint overview before the patch:
1. Outside `threadlocal!`, then exit early.
2. In `threadlocal!` and `__init` does not exist => is const already, exit early.
3. In `threadlocal!` and `__init` exists and `__init` body can be `const` => we lint.
Lint overview after the patch:
1. Outside `threadlocal!`, then exit early.
2. In `threadlocal!` and `__init` does not exist => is const already, exit early.
3. In `threadlocal!` and `__init` exists and is `const fn` => is const already, exit early.
4. In `threadlocal!` and `__init` exists and is not `const fn` and `__init` body can be `const` => we lint.
The patch adds step 3.
changelog: Fixed fp in [`thread_local_initializer_can_be_made_const`] where fallback implementation of `threadlocal!` was always linted.
## Verifying the changes
For each of these platforms [ mac, x86_64-windows-gnu, x86_64-windows-msvc ]:
1. switched to master, ran bless. Found a failure for windows-gnu.
2. switched to patch, ran bless. Success for all three platforms.
## How platform affects the lint:
The compiler performs a [conditional compilation depending on platform features](https://doc.rust-lang.org/src/std/sys/common/thread_local/mod.rs.html). The `os_local` fallback includes a call to `__init`, without step 3, we lint in all cases.
```rust
cfg_if::cfg_if! {
if #[cfg(any(all(target_family = "wasm", not(target_feature = "atomics")), target_os = "uefi"))] {
#[doc(hidden)]
mod static_local;
#[doc(hidden)]
pub use static_local::{Key, thread_local_inner};
} else if #[cfg(target_thread_local)] {
#[doc(hidden)]
mod fast_local;
#[doc(hidden)]
pub use fast_local::{Key, thread_local_inner};
} else {
#[doc(hidden)]
mod os_local;
#[doc(hidden)]
pub use os_local::{Key, thread_local_inner};
}
}
```
r? `@llogiq`
`os_local` impl of `thread_local` — regardless of whether it is const and
unlike other implementations — includes an `fn __init(): EXPR`.
Existing implementation of the lint checked for the presence of said
function and whether the expr can be made const. Because for `os_local`
we always have an `__init()`, it triggers for const implementations.
The solution is to check whether the `__init()` function is already const.
If it is `const`, there is nothing to do. Otherwise, we verify that we can
make it const.
Co-authored-by: Alejandra González <blyxyas@gmail.com>
