Downgrade unnested_or_patterns to pedantic
Even with #5704 fixed, I don't believe it is a safe bet that if someone is using or-patterns anywhere in a codebase then they want to use it as much as possible in the whole codebase. I think it would be reasonable to reevaluate after the feature is stable. I feel that a warn-by-default lint suggesting use of an unstable feature, even if already being used in one place, is questionable.
changelog: Remove unnested_or_patterns from default set of enabled lints
The code should to check that the current expression _is_ the end
expression; not that it's equal to it. The equality check seems very
wasteful in terms of performance.
New lint: suggest `ptr::read` instead of `mem::replace(..., uninitialized())`
resolves: #5575
changelog: improvements to `MEM_REPLACE_WITH_UNINIT`:
- add a new test case in `tests/ui/repl_uninit.rs` to cover the case of replacing with `mem::MaybeUninit::uninit().assume_init()`.
- modify the existing `MEM_REPLACE_WITH_UNINIT` when replacing with `mem::uninitialized` to suggest using `ptr::read` instead.
- lint with `MEM_REPLACE_WITH_UNINIT` when replacing with `mem::MaybeUninit::uninit().assume_init()`
For the following code
```rust
let c = || bar(foo.x, foo.x)
```
We generate two different `hir::Place`s for both `foo.x`.
Handling this adds overhead for analysis we need to do for RFC 2229.
We also want to store type information at each Projection to support
analysis as part of the RFC. This resembles what we have for
`mir::Place`
This commit modifies the Place as follows:
- Rename to `PlaceWithHirId`, where there `hir_id` is that of the
expressioin.
- Move any other information that describes the access out to another
struct now called `Place`.
- Removed `Span`, it can be accessed using the [hir
API](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_middle/hir/map/struct.Map.html#method.span)
- Modify `Projection` to be a strucutre of its own, that currently only
contains the `ProjectionKind`.
Adding type information to projections wil be completed as part of https://github.com/rust-lang/project-rfc-2229/issues/5
Closes https://github.com/rust-lang/project-rfc-2229/issues/3
Co-authored-by: Aman Arora <me@aman-arora.com>
Co-authored-by: Roxane Fruytier <roxane.fruytier@hotmail.com>
Stabilize Option::zip
This PR stabilizes the following API:
```rust
impl<T> Option<T> {
pub fn zip<U>(self, other: Option<U>) -> Option<(T, U)>;
}
```
This API has real world usage as seen in <https://grep.app/search?q=-%3E%20Option%3C%5C%28T%2C%5Cs%3FU%5C%29%3E®exp=true&filter[lang][0]=Rust>.
The `zip_with` method is left unstably as this API is kinda niche
and it hasn't received much usage in Rust repositories on GitHub.
cc #70086
Clean up type alias impl trait implementation
- Removes special case for top-level impl trait
- Removes associated opaque types
- Forbid lifetime elision in let position impl trait. This is consistent with the behavior for inferred types.
- Handle lifetimes in type alias impl trait more uniformly with other parameters
cc #69323
cc #63063Closes#57188Closes#62988Closes#69136Closes#73061
let_and_return: avoid "does not live long enough" errors
EDIT: Add #3324 to the list of fixes
<details>
<summary>Description of old impl</summary>
<br>
Avoid suggesting turning the RHS expression of the last statement into the block tail expression if a temporary borrows from a local that would be destroyed before.
This is my first incursion into MIR so there's probably room for improvement!
</details>
Avoid linting if the return type of some method or function called in the last statement has a lifetime parameter.
changelog: Fix false positive in [`let_and_return`]
Fixes#3792Fixes#3324
Make `PolyTraitRef::self_ty` return `Binder<Ty>`
This came up during review of #71618. The current implementation is the same as a call to `skip_binder` but harder to audit. Make it preserve binding levels and add a call to `skip_binder` at all use sites so they can be audited as part of #72507.
Give corrected code
This PR adds corrected code for doc examples.
I did this in several commits to facilitate review.
Don't hesitate to tell me if I forgot some.
Also, sometimes I felt it was not necessary to give corrected code, but I maybe wrong.
fixes: #4829
changelog: Improve documentation examples across multiple lints.
New lint: iter_next_slice
Hello, this is a work-in-progress PR for issue: https://github.com/rust-lang/rust-clippy/issues/5572
I have implemented lint to replace `iter().next()` for `slice[index..]` and `array` with `get(index)` and `get(0)` respectively. However since I made a lot of changes, I would like to request some feedback before continuing so that I could fix mistakes.
Thank you!
---
changelog: implement `iter_next_slice` lint and test, and modify `needless_continues`, `for_loop_over_options_result` UI tests since they have `iter().next()`
Add regression test for endless loop / update `pulldown_cmark`
Closes#4917
This was fixed in pulldown_cmark 0.7.1, specifically raphlinus/pulldown-cmark#438
changelog: none
Rework suggestion generation of `unit_arg` lint
Found this bug while running `cargo fix --clippy` on quite a big codebase:
This would replace something like:
```rust
Some(fn_that_actually_does_something(&a, b))
```
with
```rust
Some(())
```
which obviously suppresses side effects.
Since pretty much every expression could have side effects, I think making this suggestion `MaybeIncorrect` is the best thing to do here.
A correct suggestion would be:
```rust
fn_that_actually_does_something(&a, b);
Some(())
```
Somehow the suggestion is not correctly applied to the arguments, when more than one argument is a unit value. I have to look into this a little more, though.
changelog: Fixes suggestion of `unit_arg` lint, so that it suggests semantic equivalent code
Fixes#4741
len_zero: skip ranges if feature `range_is_empty` is not enabled
If the feature is not enabled, calling `is_empty()` on a range is ambiguous. Moreover, the two possible resolutions are unstable methods, one inherent to the range and the other being part of the `ExactSizeIterator` trait.
Since `len_zero` only checks for existing `is_empty()` inherent methods, we only take into account the `range_is_empty` feature.
Related: https://github.com/rust-lang/rust/issues/48111#issuecomment-445132965
changelog: len_zero: avoid linting ranges without #![feature(range_is_empty)]
Fixes: #3807
Extend useless conversion
This PR extends `useless_conversion` lint with `TryFrom` and `TryInto`
fixes: #5344
changelog: Extend `useless_conversion` with `TryFrom` and `TryInto`
Make empty_line_after_outer_attr an early lint
Fixes#5567
Unfortunately I couldn't find a way to reproduce the issue without syn/quote. Considering that most real-world macros use syn and/or quote, I think it's okay to pull them in anyway.
changelog: Fix false positive in [`empty_line_after_outer_attr`]
reversed_empty_ranges: add suggestion for &slice[N..N]
As discussed in the issue thread, the user accepted this solution. Let me know if this is what we want, or if changing the way we lint the N..N case is prefered.
changelog: reversed_empty_ranges: add suggestion for &slice[N..N]
Closes#5628
ptr_arg: honor `allow` attribute on arguments
The `intravisit::Visitor` impl for `LateContextAndPass` only takes into account the attributes of a function parameter inside the `check_param` method. `ptr_arg` starts its heuristics at `check_item` / `check_impl_item` / `check_trait_item`, so the `allow` is not taken into account automatically.
changelog: ptr_arg: honor `allow` attribute on arguments
Fixes#5644
new_without_default: do not suggest deriving
---
changelog: do not suggest deriving `Default` in `new_without_default`
This commit changes the behavior of the `new_without_default` lint to not suggest deriving `Default`. This suggestion is misleading if the `new` implementation does something different than what a derived `Default` implementation would do, because then the two methods would not be equivalent.
Instead, the `can_derive_default` check is removed, and we always suggest implementing `Default` in terms of `new()`.
Clarify the documentation of the `unnecessary_mut_passed` lint
fixes#5433 by replacing "giving" with "passing"
changelog: Clarifies documentation for `unnecessary_mut_passed`
Add to the list of words clippy::doc_markdown ignores
"TypeScript" is the only one of these I actually ran into organically; I can remove the others if they're too much.
changelog: Add to the list of words `clippy::doc_markdown` ignores
New lint: `match_wildcard_for_single_variants`
changelog: Added a new lint match_wildcard_for_single_variants to warn on enum matches where a wildcard is used to match a single variant
Closes#5556
Rename lint `identity_conversion` to `useless_conversion`
Lint name `identity_conversion` was misleading, so this PR renames it to `useless_conversion`.
As decision has not really came up in the issue comments, this PR will probably need discussion.
fixes#3106
changelog: Rename lint `identity_conversion` to `useless_conversion`
Merge some lints together
This PR merges following lints:
- `block_in_if_condition_expr` and `block_in_if_condition_stmt` → `blocks_in_if_conditions`
- `option_map_unwrap_or`, `option_map_unwrap_or_else` and `result_map_unwrap_or_else` → `map_unwrap`
- `option_unwrap_used` and `result_unwrap_used` → `unwrap_used`
- `option_expect_used` and `result_expect_used` → `expect_used`
- `wrong_pub_self_convention` into `wrong_self_convention`
- `for_loop_over_option` and `for_loop_over_result` → `for_loops_over_fallibles`
Lints that have already been merged since the issue was created:
- [x] `new_without_default` and `new_without_default_derive` → `new_without_default`
Need more discussion:
- `string_add` and `string_add_assign`: do we agree to merge them or not? Is there something more to do? → **not merge finally**
- `identity_op` and `modulo_one` → `useless_arithmetic`: seems outdated, since `modulo_arithmetic` has been created.
fixes#1078
changelog: Merging some lints together:
- `block_in_if_condition_expr` and `block_in_if_condition_stmt` → `blocks_in_if_conditions`
- `option_map_unwrap_or`, `option_map_unwrap_or_else` and `result_map_unwrap_or_else` → `map_unwrap_or`
- `option_unwrap_used` and `result_unwrap_used` → `unwrap_used`
- `option_expect_used` and `result_expect_used` → `expect_used`
- `for_loop_over_option` and `for_loop_over_result` → `for_loops_over_fallibles`
Literal error reporting cleanup
While doing some performance work, I noticed some code duplication in `librustc_parser/lexer/mod.rs`, so I cleaned it up.
This PR is probably best reviewed commit by commit.
I'm not sure what the API stability practices for `librustc_lexer` are. Four public methods in `unescape.rs` can be removed, but two are used by clippy, so I left them in for now.
I could open a PR for Rust-Analyzer when this one lands.
But how do I open a PR for clippy? (Git submodules are frustrating to work with)
identity_op: allow `1 << 0`
I went for accepting `1 << 0` verbatim instead of something more general as it seems to be what everyone in the issue thread needed.
changelog: identity_op: allow `1 << 0` as it's a common pattern in bit manipulation code.
Fixes#3430
Downgrade useless_let_if_seq to nursery
I feel that this lint has the wrong balance of incorrect suggestions for a default-enabled lint.
The immediate code I faced was something like:
```rust
fn main() {
let mut good = do1();
if !do2() {
good = false;
}
if good {
println!("good");
}
}
fn do1() -> bool { println!("1"); false }
fn do2() -> bool { println!("2"); false }
```
On this code Clippy calls it unidiomatic and suggests the following diff, which has different behavior in a way that I don't necessarily want.
```diff
- let mut good = do1();
- if !do2() {
- good = false;
- }
+ let good = if !do2() {
+ false
+ } else {
+ do1()
+ };
```
On exploring issues filed about this lint, I have found that other users have also struggled with inappropriate suggestions (https://github.com/rust-lang/rust-clippy/issues/4124, https://github.com/rust-lang/rust-clippy/issues/3043, https://github.com/rust-lang/rust-clippy/issues/2918, https://github.com/rust-lang/rust-clippy/issues/2176) and suggestions that make the code worse (https://github.com/rust-lang/rust-clippy/issues/3769, https://github.com/rust-lang/rust-clippy/issues/2749). Overall I believe that this lint is still at nursery quality for now and should not be enabled.
---
changelog: Remove useless_let_if_seq from default set of enabled lints
Reversed empty ranges
This lint checks range expressions with inverted limits which result in empty ranges. This includes also the ranges used to index slices.
The lint reverse_range_loop was covering iteration of reversed ranges in a for loop, which is a subset of what this new lint covers, so it has been removed. I'm not sure if that's the best choice. It would be doable to check in the new lint that we are not in the arguments of a for loop; I went for removing it because the logic was too similar to keep them separated.
changelog: Added reversed_empty_ranges lint that checks for ranges where the limits have been inverted, resulting in empty ranges. Removed reverse_range_loop which was covering a subset of the new lint.
Closes#4192Closes#96
Extend example for the `unneeded_field_pattern` lint
Current example is incorrect (or pseudo-code) because a struct name is omitted. I have used the code from the tests instead. Perhaps this example can be made less verbose, but I think it is more convenient to see a "real" code as an example.
---
changelog: extend example for the `unneeded_field_pattern` lint
Fix match on vec items: match on vec[..]
- Added new tests
- Fixed false positive when matching on full range, which will never panic
Closes#5551
changelog: fix match_on_vec_items when matching full range
Fix `unnecessary_unwrap` lint when checks are done in parameters
Fixes a false positive in `unnecessary_unwrap` lint when checks are done in macro parameters.
FIxes#5174
changelog: Fixes a false positive in `unnecessary_unwrap` lint when checks are done in macro parameters.
Fix FP on while-let-on-iterator
- fix `is_refutable` for slice patterns
- fix `is_refutable` for bindings
- add some TODO-s for cases, which can not be fixed easily
fixes#3780
changelog: fix FP on while-let-on-iterator for arrays and bindings
Implement the manual_non_exhaustive lint
Some implementation notes:
* Not providing automatic fixups because additional changes may be needed in other parts of the code, e.g. when constructing a struct.
* Even though the attribute is valid on enum variants, it's not possible to use the manual implementation of the pattern because the visibility is always public, so the lint ignores enum variants.
* Unit structs are also ignored, it's not possible to implement the pattern manually without fields.
* The attribute is not accepted in unions, so those are ignored too.
* Even though the original issue did not mention it, tuple structs are also linted because it's possible to apply the pattern manually.
changelog: Added the manual non-exhaustive implementation lint
Closes#2017
Fix the bugs of `manual_memcpy`, simplify the suggestion and refactor it
While I’m working on the long procrastinated work to expand `manual_memcpy`(#1670), I found a few minor bugs and probably unidiomatic or old coding style. There is a brief explanation of changes to the behaviour this PR will make below. And, I have a questoin: do I need to add tests for the first and second fixed bugs? I thought it might be too rare cases to include the tests for those. I added for the last one though.
* Bug fix
* It negates resulted offsets (`src/dst_offset`) when `offset` is subtraction by 0. This PR will remove any subtraction by 0 as a part of minification.
```rust
for i in 0..5 {
dst[i - 0] = src[i];
}
```
```diff
warning: it looks like you're manually copying between slices
--> src/main.rs:2:14
|
LL | for i in 0..5 {
- | ^^^^ help: try replacing the loop by: `dst[..-5].clone_from_slice(&src[..5])`
+ | ^^^^ help: try replacing the loop by: `dst[..5].clone_from_slice(&src[..5])`
|
```
* It prints `RangeTo` or `RangeFull` when both of `end` and `offset` are 0, which have different meaning. This PR will print 0. I could reject the cases `end` is 0, but I thought I won’t catch other cases `reverse_range_loop` will trigger, and it’s over to catch every such cases.
```rust
for i in 0..0 {
dst[i] = src[i];
}
```
```diff
warning: it looks like you're manually copying between slices
--> src/main.rs:2:14
|
LL | for i in 0..0 {
- | ^^^^ help: try replacing the loop by: `dst.clone_from_slice(&src[..])`
+ | ^^^^ help: try replacing the loop by: `dst[..0].clone_from_slice(&src[..0])`
|
```
* it prints four dots when `end` is `None`. This PR will ignore any `for` loops without `end` because a `for` loop that takes `RangeFrom` as its argument and contains indexing without the statements or the expressions that end loops such as `break` will definitely panic, and `manual_memcpy` should ignore the loops with such control flow.
```rust
fn manual_copy(src: &[u32], dst: &mut [u32]) {
for i in 0.. {
dst[i] = src[i];
}
}
```
```diff
-warning: it looks like you're manually copying between slices
- --> src/main.rs:2:14
- |
-LL | for i in 0.. {
- | ^^^ help: try replacing the loop by: `dst[....].clone_from_slice(&src[....])`
- |
```
* Simplification of the suggestion
* It prints 0 when `start` or `end` and `offset` are same (from #3323). This PR will use `RangeTo`
changelog: fixed the bugs of `manual_memcpy` and also simplify the suggestion.
Current example is incorrect (or pseudo-code) because a struct name is omitted. I have used the code from the tests instead. Perhaps this example can be made less verbose, but I think it is more convenient to see a "real" code as an example.
New lint `match_vec_item`
Added new lint to warn a match on index item which can panic. It's always better to use `get(..)` instead.
Closes#5500
changelog: New lint `match_on_vec_items`
- Show just one error message with multiple suggestions in case of
using multiple times an OS in target family position
- Only suggest #[cfg(unix)] when the OS is in the Unix family
- Test all the operating systems
