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`.
New Lint: inspect_then_for_each
**Work In Progress**
This PR addresses [Issue 5209](https://github.com/rust-lang/rust-clippy/issues/5209) and adds a new lint called `inspect_then_for_each`.
Current seek some guidance.
If you added a new lint, here's a checklist for things that will be
checked during review or continuous integration.
- \[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`
[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
---
changelog: Add [`inspect_for_each`] lint for the use of `inspect().for_each()` on `Iterators`.
Case sensitive file extensions
Closes#6425
Looks for ends_with methods calls with case sensitive extension comparisons.
changelog: Add new lint that warns about case-sensitive file extension comparisons.
New lint: vec_init_then_push
fixes: #1483
This will trigger on `new`, `default`, and `with_capacity` when the given capacity is less than or equal to the number of push calls. Is there anything else this should trigger on?
changelog: Added lint: `vec_init_then_push`
This splits up clippy::collapsible_if into collapsible_if for
if x {
if y { }
}
=>
if x && y { }
and collapsible_else_if for
if x {
} else {
if y { }
}
=>
if x {
} else if y {
}
so that we can lint for only the latter but not the first if we desire.
changelog: collapsible_if: split up linting for if x {} else { if y {} } into collapsible_else_if lint
needless_doctest_main: handle correctly parse errors
Before this change, finding an error when parsing a doctest would make Clippy exit without emitting an error. Now we properly catch a fatal error and ignore it.
Also, if a doctest specifies an edition in the info line, it will be used when parsing it.
changelog: needless_doctest_main: handle correctly parse errors
Fixes#6022
Add MSRV to more lints specified in #6097
add MSRV to more lints specified in #6097
add instructions for adding msrv in other lints
update tests
- [x] `redundant_field_names` requires Rust 1.17 due to suggest feature stablized in that version.
- [x] `redundant_static_lifetimes` requires Rust 1.17 due to suggest feature stablized in that version.
- [x] `filter_map_next` requires Rust 1.30 due to suggest `Iterator::find_map`.
- [x] `checked_conversions` requires Rust 1.34 due to suggest `TryFrom`.
- [x] `match_like_matches_macro` requires Rust 1.42 due to suggest `matches!`. Addressed in #6201
- [x] `manual_strip` requires Rust 1.45 due to suggest `str::{strip_prefix, strip_suffix}`. Addressed in #6201
- [x] `option_as_ref_deref` requires Rust 1.40 due to suggest `Option::{as_deref, as_deref_mut}`. Addressed in #6201
- [x] `manual_non_exhaustive` requires Rust 1.40 due to suggest `#[non_exhaustive]`. Addressed in #6201
- [x] `manual_range_contains` requires Rust 1.35 due to suggest `Range*::contains`.
- [x] `use_self` requires Rust 1.37 due to suggest `Self::Variant on enum`.
- [x] `mem_replace_with_default` requires Rust 1.40 due to suggest `mem::take`.
- [x] `map_unwrap_or` requires Rust 1.41 due to suggest `Result::{map_or, map_or_else}`.
- [x] `missing_const_for_fn` requires Rust 1.46 due to `match/if/loop in const fn` needs that version.
changelog: Add MSRV config to more lints. ^This is now the complete list, AFAWK
Add lint print_stderr
Resolves#6348
Almost identical to print_stdout, this lint applies to the `eprintln!` and `eprint!` macros rather than `println!` and `print!`.
changelog: Add new lint [`print_stderr`]. [`println_empty_string`] and [`print_with_newline`] now apply to `eprint!()` and `eprintln!()` respectively.
Moved map_err_ignore to restriction and updated help message
This MR moves map_err_ignore lint from `pedantic` to the `restriction` category of lints and updates the help message to give the user an option to ignore the lint by naming the closure variable e.g. `.map_err(|_ignored| ...`
---
changelog: move map_err_ignore to restriction category
Specifically ptr::{sub, wrapping_sub, add, wrapping_add, offset, wrapping_offset} and slice::{from_raw_parts, from_raw_parts_mut}
The lint now also looks for size_of calls through casts (Since offset takes an isize)
Also fix review comments:
- Use const arrays and iterate them for the method/function names
- merge 2 if_chain's into one using a rest pattern
- remove unnecessary unsafe block in test
And make the lint only point to the count expression instead of the entire function call
Add Collapsible match lint
changelog: Add collapsible_match lint
Closes#1252Closes#2521
This lint finds nested `match` or `if let` patterns that can be squashed together. It is designed to be very conservative to only find cases where merging the patterns would most likely reduce cognitive complexity.
Example:
```rust
match result {
Ok(opt) => match opt {
Some(x) => x,
_ => return,
}
_ => return,
}
```
to
```rust
match result {
Ok(Some(x)) => x,
_ => return,
}
```
These criteria must be met for the lint to fire:
* The inner match has exactly 2 branches.
* Both the outer and inner match have a "wild" branch like `_ => ..`. There is a special case for `None => ..` to also be considered "wild-like".
* The contents of the wild branches are identical.
* The binding which "links" the matches is never used elsewhere.
Thanks to the hir, `if let`'s are easily included with this lint since they are desugared into equivalent `match`'es.
I think this would fit into the style category, but I would also understand changing it to pedantic.
run `cargo dev new_lint --category correctness --name suspicious_chained_operators --pass early`
add (currently failing) tests for suspicious_chained_operators
add some tests to answer a question that came up during implementation
write usage code for functions we'll need to find or create
Complete left-right tracking TODO
get it compiling with several `todo!` invocations.
refactor to a set of incomplete functions that don't expect to be able to edit a `Span`
create placeholder for `suggestion_with_swapped_ident` function and correct some comments
add `inside_larger_boolean_expression` test
fill out `get_ident` and `suggestion_with_swapped_ident`
Implementi the `IdentIter`
start on implementing the `IdentIter`
handle the `ExprKind::Path` case in `IdentIter`
on second thought, make the iterator type dynamic so we don't need an explicit type for each one we will need
handle `ExprKind::MacCall` in `IdentIter`
Try handling `box x` expressions
restructure `IdentIter`
set `self.done` when returning `None`
Handle `ExprKind::Array`
reduce duplication with a macro that we expect to use several more times
handle ExprKind::Call
add `new_p` convenience method
handle `MethodCall`
handle `Tup` and `Binary`
handle `Unary`
simplify by not returning an additional `Expr` from the `IdentIter`
add cross product test against false positives
rename suspicious_chained_operators to suspicious_operation_groupings within files
For the record, the exact commands run were:
find . -type f -name "*.md" -exec sed -i 's/suspicious_chained_operators/suspicious_operation_groupings/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/suspicious_chained_operators/suspicious_operation_groupings/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/SUSPICIOUS_CHAINED_OPERATORS/SUSPICIOUS_OPERATION_GROUPINGS/g' {} +
find . -type f -name "*.rs" -exec sed -i 's/SuspiciousChainedOperators/SuspiciousOperationGroupings/g' {} +
Also:
rename file to match module name
rename test file to match lint name
start implementing `IdentDifference` creation
add `IdentIter` utility
use `ident_iter::IdentIter`
fix bug in `suggestion_with_swapped_ident`
add `inside_if_statements` test
implement `Add` `todo`s
register `SuspiciousOperationGroupings` lint pass
fill in `chained_binops`, and fill in a stopgap version of `ident_difference_expr`, but then notice that the lint does not seem to ever be run in the tests
run `cargo dev update_lints` and not that the `suspicious_operation_groupings` lint still does not seem to be run
fix base index incrementing bug
fix paired_identifiers bug, and remove ident from `Single`
change help prefix and note our first successful lint messages!
add odd_number_of_pairs test
get the `non_boolean_operators` test passing, with two copies of the error message
extract `is_useless_with_eq_exprs` so we can know when `eq_op` will already handle something
add `not_caught_by_eq_op` tests since `s1.b * s1.b` was (reasonably) not caught by `eq_op`
cover the case where the change should be made on either side of the expression with `not_caught_by_eq_op` tests
produce the expected suggestion on the `not_caught_by_eq_op_middle_change_left` test
confirm that the previous tests still pass and update references
fix early continue bug and get `not_caught_by_eq_op_middle_change_right` passing
note that `not_caught_by_eq_op_start` already passes
fix bugs based on misunderstanding of what `Iterator::skip` does, and note that `not_caught_by_eq_op_end` now passes
add several parens tests and make some of them pass
handle parens inside `chained_binops_helper` and note that this makes several tests pass
get `inside_larger_boolean_expression_with_unsorted_ops` test passing by extracting out `check_same_op_binops` function
also run `cargo dev fmt`
note that `inside_function_call` already passes
add another `if_statement` test
remove the matching op requirement, making `inside_larger_boolean_expression_with_unsorted_ops` pass
prevent non-change suggestions from being emitted
get the `Nested` tests passing, and remove apparently false note about eq_op
add a test to justify comment in `ident_difference_expr_with_base_location` but find that the failure mode seems different than expected
complete `todo` making `do_not_give_bad_suggestions_for_this_unusual_expr` pass and add some more tests that already pass
add test to `eq_op`
note that `inside_fn_with_similar_expression` already passes
fix `inside_an_if_statement` and note that it already passes
attempt to implement if statement extraction and notice that we don't seem to handle unary ops correctly
add `maximum_unary_minus_right_tree` test and make it pass
add two tests and note one of them passes
filter out unary operations in several places, and find that the issue seems to be that we don't currently recognize the error in `multiple_comparison_types_and_unary_minus` even so.
remove filtering that was causing bad suggestions
remove tests that were deemed too much for now
run `cargo dev fmt`
correct eq_op post-merge
fill out the description and delete debugging code
run `cargo dev update_lints`
update eq_op references
add parens to work around rustfmt issue #3666 and run rustfmt
https://github.com/rust-lang/rustfmt/issues/3666#issuecomment-714612257
update references after formatting
fix dogfood issues
fix multi-cursor edit
fix missed dogfood error
fix more dogfood pedantic issues, including function length
even more nesting
insert hidden definition of Vec3 so docs compile
add spaces to second struct def
reword test description comment
Co-authored-by: llogiq <bogusandre@gmail.com>
add local `use BinOpKind::*;`
Apply suggestions from code review
Co-authored-by: llogiq <bogusandre@gmail.com>
switch `SUSPICIOUS_OPERATION_GROUPINGS` to a style lint
run `cargo dev update_lints`
put both usages of `op_types` in the same closure to satisfy `borrowck`
fix compile error
Check when `from_utf8` is called from sliced byte array from string
---
*Please keep the line below*
changelog: Fix#5487: Add linter to check when `from_utf8` is called from sliced byte array from string.
Add lint for 'field_reassign_with_default` #568
changelog: Add lint for field_reassign_with_default that checks if mutable object + field modification is used to edit a binding initialized with Default::default() instead of struct constructor.
Fixes#568
Notes:
- Checks for reassignment of one or more fields of a binding initialized with Default::default().
- Implemented using EarlyLintPass, might be future proofed better with LateLintPass.
- Does not trigger if Default::default() is used via another type implementing Default.
- This is a re-open of [PR#4761](https://github.com/rust-lang/rust-clippy/pull/4761), but I couldn't figure out how to re-open that one so here's a new one with the requested changes :S
Add lint 'ref_option_ref' #1377
This lint checks for usage of `&Option<&T>` which can be simplified as `Option<&T>` as suggested in #1377.
This WIP PR is here to get feedback on the lint as there's more cases to be handled:
* statics/consts,
* associated types,
* type alias,
* function/method parameter/return,
* ADT definitions (struct/tuple struct fields, enum variants)
changelog: Add 'ref_option_ref' lint
Add lint: from_iter_instead_of_collect
Fixes#5679
This implements lint for `::from_iter()` from #5679 not the general issue (`std::ops::Add::add`, etc.).
This lint checks if expression is function call with `from_iter` name and if it's implementation of the `std::iter::FromIterator` trait.
changelog: Introduce from_iter_instead_of_collect lint
single_char_insert_str: lint using insert_str() on single-char literals and suggest insert()
Fixes#6026
changelog: add single_char_insert_str lint which lints using string.insert_str() with single char literals and suggests string.insert() with a char
- Implement `field_reassign_with_default` as a `LateLintPass`
- Avoid triggering `default_trait_access` on a span already linted by
`field_reassigned_with_default`
- Merge `default_trait_access` and `field_reassign_with_default` into
`Default`
- Co-authored-by: Eduardo Broto <ebroto@tutanota.com>
- Fixes#568
Add lint for comparing to empty slices instead of using .is_empty()
Hey first time making a clippy lint
I added the implementation of the lint the `len_zero` since it shared a lot of the code, I would otherwise have to rewrite. Just tell me if the lint should use it's own file instead
changelog: Add lint for comparing to empty slices
Fixes#6217
New lint: manual-range-contains
This fixes#1110, at least for the contains-suggesting part.
- \[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`
---
changelog: new lint: manual-range-contains
Add lint for `&mut Mutex::lock`
Fixes#1765
changelog: Add lint [`mut_mutex_lock`] for `&mut Mutex::lock` and suggests using `&mut Mutex::get_mut` instead.
Add new lint for undropped ManuallyDrop values
Adds a new lint for the following code:
```rust
struct S;
impl Drop for S {
fn drop(&mut self) {
println!("drip drop");
}
}
fn main() {
// This will not drop the `S`!!!
drop(std::mem::ManuallyDrop::new(S));
unsafe {
// This will.
std::mem::ManuallyDrop::drop(&mut std::mem::ManuallyDrop::new(S));
}
}
```
The inner value of a `ManuallyDrop` will not be dropped unless the proper, unsafe drop function is called on it. This lint makes sure that a user does not accidently use the wrong function and forget to drop a `ManuallyDrop` value.
Fixes#5581.
---
*Please keep the line below*
changelog: none
Add lint for holding RefCell Ref across an await
Fixes#6008
This introduces the lint await_holding_refcell_ref. For async functions, we iterate
over all types in generator_interior_types and look for `core::cell::Ref` or `core::cell::RefMut`. If we find one then we emit a lint.
Heavily cribs from: https://github.com/rust-lang/rust-clippy/pull/5439
changelog: introduce the await_holding_refcell_ref lint
Refactor trivially_copy_pass_by_ref and the new lint into pass_by_ref_or_value module
Update stderr of conf_unknown_key test
Rename lint to large_types_passed_by_value
Increase `pass_by_value_size_limit` default value to 256
Improve rules for `large_types_passed_by_value`
Improve tests for `large_types_passed_by_value`
Improve documentation for `large_types_passed_by_value`
Make minor corrections to pass_by_ref_or_value.rs suggested by clippy itself
Fix `large_types_passed_by_value` example and improve docs
pass_by_ref_or_value: Tweak check for mut annotation in params
large_types_passed_by_value: add tests for pub trait, trait impl and inline attributes
New lint: Recommend using `ptr::eq` when possible
This is based almost entirely on the code available in the previous PR #4596. I merely updated the code to make it compile.
Fixes#3661.
- [ ] I'm not sure about the lint name, but it was the one used in the original PR.
- [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`
---
changelog: none
Downgrade string_lit_as_bytes to nursery
Between #1402 (regarding `to_owned`) and #4494 (regarding `impl Read`), as well as other confusion I've seen hit in my work codebase involving string_lit_as_bytes (`"...".as_bytes().into()`), I don't think this lint is at a quality to be enabled by default.
I would consider re-enabling this lint after it is updated to understand when the surrounding type information is sufficient to unsize `b"..."` to &\[u8\] without causing a type error.
As currently implemented, this lint is pushing people to write `&b"_"[..]` which is not an improvement over `"_".as_bytes()` as far as I am concerned.
---
changelog: Remove string_lit_as_bytes from default set of enabled lints
Downgrade rc_buffer to restriction
I think Arc\<Vec\<T\>\> and Arc\<String\> and similar are a totally reasonable data structure, as observed by others in the comments on [#6044](https://github.com/rust-lang/rust-clippy/pull/6044#event-3799579830) as well. Doing `Arc::make_mut(&mut self.vec).push(...)` or `Arc::make_mut(&mut self.string).push_str("...")` is a terrific and well performing copy-on-write pattern. Linting this with an enabled-by-default <kbd>performance</kbd> lint strikes me as an unacceptable false positive balance.
As of #6090 the documentation of this lint now contains:
> **Known problems:** This pattern can be desirable ...
which should indicate that we shouldn't be linting against correct, reasonable, well-performing patterns with an enabled-by-default lint.
Mentioning #6044, #6090.
r? `@yaahc,` who reviewed the lint.
---
changelog: Remove rc_buffer from default set of enabled lints
Lint for invisible Unicode characters other than ZWSP
This PR extends the existing `zero_width_space` lint to look for other invisible characters as well (in this case, `\\u{ad}` soft hyphen.
I feel like this lint is the logical place to add the check, but I also realize the lint name is not particularly flexible, but I also understand that it shouldn't be renamed for compatibility reasons.
Open questions:
- What other characters should trigger the lint?
- What should be done with the lint name?
- How to indicate the change in functionality?
Motivation behind this PR: https://github.com/rust-lang/rust/issues/77417 - I managed to shoot myself in the foot by an invisible character pasted into my test case.
changelog: rename [`zero_width_space`] to [`invisible_characters`] and add SHY and WJ to the list.
Add `rc_buffer` lint for checking Rc<String> and friends
Fixes#2623
This is a bit different from the original PR attempting to implement this type of lint. Rather than linting against converting into the unwanted types, this PR lints against declaring the unwanted type in a struct or function definition.
I'm reasonably happy with what I have here, although I used the fully qualified type names for the Path and OsString suggestions, and I'm not sure if I should have just used the short versions instead, even if they might not have been declared via use.
Also, I don't know if "buffer type" is the best way to put it or not. Alternatively I could call it a "growable type" or "growable buffer type", but I was thinking of PathBuf when I started making the lint.
changelog: Add `rc_buffer` lint
Add map_err_ignore lint
In a large code base a lot of times errors are ignored by using something like:
```rust
foo.map_err(|_| Some::Enum)?;
```
This drops the original error in favor of a enum that will not have the original error's context. This lint helps catch throwing away the original error in favor of an enum without its context.
---
*Please keep the line below*
changelog: Added map_err_ignore lint
Add a new lint, `manual-strip`, that suggests using the `str::strip_prefix`
and `str::strip_suffix` methods introduced in Rust 1.45 when the same
functionality is performed 'manually'.
Closes#5734
Add lint panic in result
### Change
Adding a new "restriction" lint that will emit a warning when using "panic", "unimplemented" or "unreachable" in a function of type option/result.
### Motivation
Some codebases must avoid crashes at all costs, and hence functions of type option/result must return an error instead of crashing.
### Test plan
Running:
TESTNAME=panic_in_result cargo uitest ---
changelog: none
This catches bugs of the form
tokio::spawn(async move {
let f = some_async_thing();
f // Oh no I forgot to await f so that work will never complete.
});
Warn about assignments where left-hand side place expression is the same
as right-hand side value expression. For example, warn about assignment in:
```rust
pub struct Event {
id: usize,
x: i32,
y: i32,
}
pub fn copy_position(a: &mut Event, b: &Event) {
a.x = b.x;
a.y = a.y;
}
```
This lint catches cases where the last statement of a closure expecting
an instance of Ord has a trailing semi-colon. It compiles since the
closure ends up return () which also implements Ord but causes
unexpected results in cases such as sort_by_key.
Fixes#5080
reprise: rebase, update and address all concerns
Move range_minus_one to pedantic
This moves the range_minus_one lint to the pedantic category, so there
will not be any warnings emitted by default. This should work around
problems where the suggestion is impossible to resolve due to the range
consumer only accepting a specific range implementation, rather than the
`RangeBounds` trait (see #3307).
While it is possible to work around this by extracting the boundary into
a variable, I don't think clippy should encourage people to disable or
work around lints, but instead the lints should be fixable. So hopefully
this will help until a proper implementation checks what the range is
used for.
*Please keep the line below*
changelog: move [`range_minus_one`] to pedantic
Added restriction lint: pattern-type-mismatch
changelog: Added a new restriction lint `pattern-type-mismatch`. This lint is especially helpful for beginners learning about the magic behind pattern matching. (This explanation might be worth to include in the next changelog.)
#5626: lint iterator.map(|x| x)
changelog: adds a new lint for iterator.map(|x| x) (see https://github.com/rust-lang/rust-clippy/issues/5626)
The code also lints for result.map(|x| x) and option.map(|x| x). Also, I'm not sure if I'm checking for type adjustments correctly and I can't think of an example where .map(|x| x) would apply type adjustments.
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
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()`
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`
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
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`
Fixes#4226
This introduces the lint await_holding_lock. For async functions, we iterate
over all types in generator_interior_types and look for types named MutexGuard,
RwLockReadGuard, or RwLockWriteGuard. If we find one then we emit a lint.
If let else mutex
changelog: Adds lint to catch incorrect use of `Mutex::lock` in `if let` expressions with lock calls in any of the blocks.
closes: #5219
Add lint on large non scalar const
This PR adds the new lint `non_scalar_const` that aims to warn against `const` declaration of large arrays. For performance, because of inlining, large arrays should be preferably declared as `static`.
Note: i made this one to warn on all const arrays, whether they are in a body function or not. I don't know if this is really necessary, i could just reduce this lint to variables out of function scope.
Fixes: #400
changelog: add new lint for large non-scalar types declared as const
Downgrade implicit_hasher to pedantic
From the [documentation](https://rust-lang.github.io/rust-clippy/master/index.html#implicit_hasher), this lint is intended to suggest:
```diff
- pub fn foo(map: &mut HashMap<i32, i32>) { }
+ pub fn foo<S: BuildHasher>(map: &mut HashMap<i32, i32, S>) { }
```
I think this is pedantic. I get that this lint can benefit core libraries like serde, but that's exactly the use case for pedantic lints; a library like serde will [enable clippy_pedantic](fd6741f4b0/src/lib.rs (L304)) and take the time to go through everything possible. Similar for libraries doing a libz blitz style checkup before committing to a 1.0 release; it would make sense to run through all the available pedantic lints then.
But otherwise, for most codebases and certainly for industrial codebases, the above suggested change just makes the codebase more obtuse for questionable benefit.
changelog: Remove implicit_hasher from default set of enabled lints
Downgrade unreadable_literal to pedantic
As motivated by #5418. This is the top most commonly suppressed Clippy style lint, which indicates that the community has decided they don't share Clippy's opinion on the best style of this.
I've left the lint in as pedantic, though it could be that "restriction" would be better -- I can see this lint being useful as an opt-in restriction in some codebases.
changelog: Remove unreadable_literal from default set of enabled lints
Add new lint for `Result<T, E>.map_or(None, Some(T))`
Fixes#5414
PR Checklist
---
- [x] Followed lint naming conventions (the name is a bit awkward, but it seems to conform)
- [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
`Result<T, E>` has an [`ok()`](https://doc.rust-lang.org/std/result/enum.Result.html#method.ok) method that adapts a `Result<T,E>` into an `Option<T>`.
It's possible to get around this adapter by writing `Result<T,E>.map_or(None, Some)`.
This lint is implemented as a new variant of the existing [`option_map_none` lint](https://github.com/rust-lang/rust-clippy/pull/2128)
Downgrade inefficient_to_string to pedantic
From the [documentation](https://rust-lang.github.io/rust-clippy/master/index.html#inefficient_to_string):
> ```diff
> - ["foo", "bar"].iter().map(|s| s.to_string());
>
> + ["foo", "bar"].iter().map(|&s| s.to_string());
> ```
I feel like saving 10 nanoseconds from the formatting machinery isn't worth asking the programmer to insert extra `&` / `*` noise in the *vast* majority of cases. This is a pedantic lint.
changelog: Remove inefficient_to_string from default set of enabled lints
Downgrade trivially_copy_pass_by_ref to pedantic
The rationale for this lint is documented as:
> In many calling conventions instances of structs will be passed through registers if they fit into two or less general purpose registers.
I think the purported performance benefits of clippy's recommendation are overstated. This isn't worth asking people to sprinkle code with more `*``*``&``*``&` to chase the alleged performance.
This should be a pedantic lint that is disabled by default and opted in if some specific performance sensitive codebase determines that it is worthwhile.
As a reminder, a typical place that a reference to a primitive would come up is if the function is used as a filter. Triggering a performance-oriented lint on this type of code is the definition of pedantic.
```rust
fn filter(_n: &i32) -> bool {
true
}
fn main() {
let v = vec![1, 2, 3];
v.iter().copied().filter(filter).for_each(drop);
}
```
```console
warning: this argument (4 byte) is passed by reference, but would be more efficient if passed by value (limit: 8 byte)
--> src/main.rs:1:15
|
1 | fn filter(_n: &i32) -> bool {
| ^^^^ help: consider passing by value instead: `i32`
```
changelog: Remove trivially_copy_pass_by_ref from default set of enabled lints
Downgrade let_unit_value to pedantic
Given that the false positive in #1502 is marked E-hard and I don't have much hope of it getting fixed, I think it would be wise to disable this lint by default. I have had to suppress this lint in every substantial codebase (\>100k line) I have worked in. Any time this lint is being triggered, it's always the false positive case.
The motivation for this lint is documented as:
> A unit value cannot usefully be used anywhere. So binding one is kind of pointless.
with this example:
> ```rust
> let x = {
> 1;
> };
> ```
Sure, but the author would find this out via an unused_variable warning or from `x` not being the type that they need further down. If there ends up being a type error on `x`, clippy's advice isn't going to help get the code compiling because it can only run if the code already compiles.
changelog: Remove let_unit_value from default set of enabled lints
Result<T, E> has an `ok()` method that adapts a Result<T,E> into an Option<T>.
It's possible to get around this adapter by writing Result<T,E>.map_or(None, Some).
This lint is implemented as a new variant of the existing
[`option_map_none` lint](https://github.com/rust-lang/rust-clippy/pull/2128)
Move verbose_file_reads to restriction
cc #5368
Using `File::read` instead of `fs::read_to_end` does make sense in multiple cases, so this lint is rather restriction, than complexity
changelog: Move [`verbose_file_reads`] to restriction
Lint for `pub(crate)` items that are not crate visible due to the visibility of the module that contains them
changelog: Add `redundant_pub_crate` lint
Closes#5274.
Add lint to detect floating point operations that can be computed more
accurately at the cost of performance. `cbrt`, `ln_1p` and `exp_m1`
library functions call their equivalent cmath implementations which is
slower but more accurate so moving checks for these under this new lint.
Merge the accuracy and efficiency lints into a single lint that
checks for improvements to accuracy, efficiency and readability
of floating-point expressions.
