Fixes#10609: Adds lint to detect construction of unit struct using `default`
Using `default` to construct a unit struct increases code complexity and adds a function call. This can be avoided by simply removing the call to `default` and simply construct by name.
changelog: [`default_constructed_unit_structs`]: detects construction of unit structs using `default`
fixes#10609
Currently a `{D,Subd}iagnosticMessage` can be created from any type that
impls `Into<String>`. That includes `&str`, `String`, and `Cow<'static,
str>`, which are reasonable. It also includes `&String`, which is pretty
weird, and results in many places making unnecessary allocations for
patterns like this:
```
self.fatal(&format!(...))
```
This creates a string with `format!`, takes a reference, passes the
reference to `fatal`, which does an `into()`, which clones the
reference, doing a second allocation. Two allocations for a single
string, bleh.
This commit changes the `From` impls so that you can only create a
`{D,Subd}iagnosticMessage` from `&str`, `String`, or `Cow<'static,
str>`. This requires changing all the places that currently create one
from a `&String`. Most of these are of the `&format!(...)` form
described above; each one removes an unnecessary static `&`, plus an
allocation when executed. There are also a few places where the existing
use of `&String` was more reasonable; these now just use `clone()` at
the call site.
As well as making the code nicer and more efficient, this is a step
towards possibly using `Cow<'static, str>` in
`{D,Subd}iagnosticMessage::{Str,Eager}`. That would require changing
the `From<&'a str>` impls to `From<&'static str>`, which is doable, but
I'm not yet sure if it's worthwhile.
Fix `items_after_test_module`: Ignore imported modules
Fixes#10713. It does a little bit of dark magic, but intention is what really counts.
changelog:[`items_after_test_module`]: Ignore imported modules (`mod foo;`) with no body.
Using `default` to construct a unit struct increases code complexity and
adds a function call. This can be avoided by simply removing the call to
`default` and simply construct by name.
Add configuration for `semicolon_block` lints
Does exactly what it says on the tin, suggests moving a block's final semicolon inside if it's multiline and outside if it's singleline.
I don't really like how this is implemented so I'm not too sure if this is ready yet. Alas, it might be ok.
---
fixes#10654
changelog: Enhancement: [`semicolon_inside_block`]: Added `semicolon-inside-block-ignore-singleline` as a new config value.
[#10656](https://github.com/rust-lang/rust-clippy/pull/10656)
changelog: Enhancement: [`semicolon_outside_block`]: Added `semicolon-outside-block-ignore-multiline` as a new config value.
[#10656](https://github.com/rust-lang/rust-clippy/pull/10656)
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Switch to `EarlyBinder` for `explicit_item_bounds`
Part of the work to finish https://github.com/rust-lang/rust/issues/105779.
This PR adds `EarlyBinder` to the return type of the `explicit_item_bounds` query and removes `bound_explicit_item_bounds`.
r? `@compiler-errors` (hope it's okay to request you, since you reviewed #110299 and #110498😃)
Improve the help message + add a help span
This would close#10410, because it applies the general consensus achieved in that issue (that replacing `let _ = ...` to `_ = ...` doesn't present any benefits).
I also added a little help message span.
changelog:[`let_underscore_untyped`]: Fix the help message confusion + add a help message span.
check for `..` pattern in `redundant_pattern_matching`
The `redundant_pattern_matching` lint currently checks for `if let Some(_) = ...`, but not for `if let Some(..) = ...`.
This PR makes sure to also check for the `..` pattern in tuple structs.
It also found one such instance in clippy itself so that shows it's worth checking for this pattern as well 😅
changelog: [`redundant_pattern_matching`]: check for `..` pattern in tuple structs
Fix false positive in `allow_attributes`
This would emit a warning if used in a proc-macro with the feature `lint_reasons` enabled. This is now fixed.
changelog: [`allow_attributes`]: Don't lint if in external macro
Ignore `shadow` warns in code from macro expansions
This PR fixes https://github.com/rust-lang/rust-clippy/issues/9757
I am in doubt if just looking for `pat.span.from_expansion()` would be sufficient instead of looking for both `pat.span.desugaring_kind().is_some()` or `pat.span.from_expansion()`. The tests (including the new one) passes if I leave the only `if pat.span.from_expansion()`. Any feedbacks?
Also, this is my first PR here, sorry for anything and thanks for the patience!
changelog: [`shadow_same`, `shadow_reuse`, `shadow_unrelated`]: avoiding warns in macro-generated code
New lint: detect `if` expressions with simple boolean assignments to the same target
Closes#10430
changelog: [`needless_bool_assign`] new lint to detect simple boolean assignment to the same target in `if` branches
Run various queries from other queries instead of explicitly in phases
These are just legacy leftovers from when rustc didn't have a query system. While there are more cleanups of this sort that can be done here, I want to land them in smaller steps.
This phased order of query invocations was already a lie, as any query that looks at types (e.g. the wf checks run before) can invoke e.g. const eval which invokes borrowck, which invokes typeck, ...
Don't suggest `suboptimal_flops` unavailable in nostd
Fixes#10634
changelog: Enhancement: [`suboptimal_flops`]: Do not suggest `{f32,f64}::abs()` or `{f32,f64}::mul_add()` in a `no_std`-environment.
Add `items_after_test_module` lint
Resolves task *3* of #10506, alongside *1* resolved at #10543 in an effort to help standarize a little bit more testing modules.
---
changelog:[`items_after_test_module`]: Added the lint.
make [`len_zero`] lint not spanning over parenthesis
sorry it should be a quick fix but I was caught up by other stuffs last couple weeks 🤦♂️
---
fixes: #10529
changelog: make [`len_zero`] lint not spanning over parenthesis
Add offset_of! macro (RFC 3308)
Implements https://github.com/rust-lang/rfcs/pull/3308 (tracking issue #106655) by adding the built in macro `core::mem::offset_of`. Two of the future possibilities are also implemented:
* Nested field accesses (without array indexing)
* DST support (for `Sized` fields)
I wrote this a few months ago, before the RFC merged. Now that it's merged, I decided to rebase and finish it.
cc `@thomcc` (RFC author)
Suppress the triggering of some lints in derived structures
Fixes#10185Fixes#10417
For `integer_arithmetic`, `arithmetic_side_effects` and `shadow_reuse`.
* ~~Not sure how to test these use-cases so feel free to point any method or any related PR.~~
---
changelog: FP: [`integer_arithmetic`], [`arithmetic_side_effects`]: No longer lint inside proc macros
[#10203](https://github.com/rust-lang/rust-clippy/pull/10203)
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Add size-parameter to unecessary_box_returns
Fixes#10641
This adds a configuration-knob to the `unecessary_box_returns`-lint which allows _not_ linting a `fn() -> Box<T>` if `T` is "large". The default byte size above which we no longer lint is 128 bytes (due to https://github.com/rust-lang/rust-clippy/issues/4652#issue-505670554, also used in #9373). The overall rational is given in #10641.
---
changelog: Enhancement: [`unnecessary_box_returns`]: Added new lint configuration `unnecessary-box-size` to set the maximum size of `T` in `Box<T>` to be linted
[#10651](https://github.com/rust-lang/rust-clippy/pull/10651)
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This allows allocating `Expr`s into a dropless arena, which is useful
for using length prefixed thing slices in HIR, since these can only be
allocated in the dropless arena and not in a typed arena. This is
something I'm working on.
Fix UB in `as_ptr_cast_mut` documentation
changelog: none
Fixes#10628
There's no `String::as_mut_ptr` surprisingly, so the example is actually calling `str::as_mut_ptr` on an empty `str`
Clear with drain
Fixes#10572: both the original intent of the issue (extending `clear_with_drain`) and the false negative for `collection_is_never_read` I found in the process are fixed by this PR.
changelog: [`clear_with_drain`]: extend to 5 other types of containers. [`collection_is_never_read`]: fix false negative for `String`s.
remove unusued `#![feature(drain_filter)]`
The unstable feature does not appear to be used and its presence blocks work in https://github.com/rust-lang/rust/pull/104455
changelog: none
fix `single_component_path_imports` FP on `self::<import>::..`
fixes#10549
I noticed that a couple functions in the file I was working on took `cx` as a parameter but didn't use them, so I removed that. Can revert if desired because it isn't related to my changes.
changelog: [`single_component_path_imports`] don't suggest removing import when it is used as `self::<import>::..`
fix [`mem_replace_option_with_none`] not considering field variables
fixes: #9824
---
changelog: fix [`mem_replace_option_with_none`] not considering field variables
Make redundant_async_block a more complete late pass
This lets us detect more complex situations: `async { x.await }` is simplified into `x` if:
- `x` is an expression without side-effect
- or `x` is an `async` block itself
In both cases, no part of the `async` expression can be part of a macro expansion.
Fixes#10509.
Fixes#10525.
changelog: [`redundant_async_block`] Do not lint expressions with side effects.
This lets us detect more complex situations: `async { x.await }` is
simplified into `x` if:
- `x` is an expression without side-effect
- or `x` is an async block itself
In both cases, no part of the `async` expression can be part of a macro
expansion.
Add `tests_outside_test_module` lint
Adds `tests_outside_test_module` from #10506. This PR **doesn't** close the issue, just resolves task 1.
changelog: [`tests_outside_test_module`]: The lint has been added
Fix bug with getting parent directories in `lookup_conf_file`
Currently `lookup_conf_file` doesn't canonicalize the configuration directory before using [`PathBuf::pop`](https://doc.rust-lang.org/std/path/struct.PathBuf.html#method.pop) to get the parent directory. This isn't usually an issue when clippy is invoked via `cargo clippy` as `CARGO_MANIFEST_DIR` is already canonicalized. However, this currently causes `clippy-driver` to ignore any `clippy.toml` in any parent directories when `CARGO_MANIFEST_DIR` and `CLIPPY_CONF_DIR` are not set.
changelog: Fix a bug that would cause parent directories not to be searched for `clippy.toml` when using `clippy-driver` directly.
Mini-fix `double_must_use` for async functions
From Rust 1.67 onwards, the `#[must_use]` attribute also applies to the `Future::Output` (rust-lang/rust#100633). So the lint `double_must_use` was linting all async functions. This PR changes the `double_must_use` lint so it ignores `async` functions.
---
Closes#10486
changelog: [`double_must_use`]: Fix false positive in async function
Initial support for return type notation (RTN)
See: https://smallcultfollowing.com/babysteps/blog/2023/02/13/return-type-notation-send-bounds-part-2/
1. Only supports `T: Trait<method(): Send>` style bounds, not `<T as Trait>::method(): Send`. Checking validity and injecting an implicit binder for all of the late-bound method generics is harder to do for the latter.
* I'd add this in a follow-up.
3. ~Doesn't support RTN in general type position, i.e. no `let x: <T as Trait>::method() = ...`~
* I don't think we actually want this.
5. Doesn't add syntax for "eliding" the function args -- i.e. for now, we write `method(): Send` instead of `method(..): Send`.
* May be a hazard if we try to add it in the future. I'll probably add it in a follow-up later, with a structured suggestion to change `method()` to `method(..)` once we add it.
7. ~I'm not in love with the feature gate name 😺~
* I renamed it to `return_type_notation` ✔️
Follow-up PRs will probably add support for `where T::method(): Send` bounds. I'm not sure if we ever want to support return-type-notation in arbitrary type positions. I may also make the bounds require `..` in the args list later.
r? `@ghost`
Add suggestions to `extra_unused_type_parameters`
Change the `extra_unused_type_parameters` lint to provide machine applicable suggestions rather than just help messages. Exception to this are cases when any unused type parameters appear bounded in where clauses - for now I've deemed these cases unfixable and separated them out. Future work might be able to provide suggestions in these cases.
Also, added a test case for the `avoid_breaking_exported_api` config option.
r? `@flip1995`
changelog: [`extra_unused_type_parameters`]: Now provides fixable suggestions.
Added the `[unnecessary_box_returns]` lint
fixes#5
I'm not confident in the name of this lint. Let me know if you can think of something better
---
changelog: New lint: ``[`unnecessary_box_returns`]``
[#9102](https://github.com/rust-lang/rust-clippy/pull/9102)
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Fix allow attribute, items from macros in `items_after_statements`
Fixes#10540
changelog: [`items_after_statements`]: Fixes `#[allow(clippy::items_after_statements)]` when applied to an item, and ignores items after statements from different macro contexts
Remove the `NodeId` of `ast::ExprKind::Async`
This is a followup to https://github.com/rust-lang/rust/pull/104833#pullrequestreview-1314537416.
In my original attempt, I was using `LoweringContext::expr`, which was not correct as it creates a fresh `DefId`.
It now uses the correct `DefId` for the wrapping `Expr`, and also makes forwarding `#[track_caller]` attributes more explicit.
Make this function work with signed integer types by extracting the
underlying type and finding the min and max values.
Change the signature to make it more consistent:
- The range is now given as an `Expr` in order to extract the type
- The container's path is now passed, and only as an `Option` so that
the function can be called in the general case without a container
fix [`cast_possible_truncation`] offering wrong suggestion for casting float to integer
fixes: #10366
---
changelog: [`cast_possible_truncation`] Fix incorrect suggestions when casting from float types or to `_`
Wrap `transmutes_expressible_as_ptr_casts` suggestions in parentheses
changelog: [`transmutes_expressible_as_ptr_casts`]: Fix suggestion missing wrapping parentheses
Fixes#10449
r? `@Jarcho`
Is this the best way to go about this? `unused_parens` will catch the unnecessary ones but emitting them in the first place isn't ideal
suggest `try_into` when casting to wildcard type;
fix [`cast_possible_truncation`] suggesting useless parenthesis;
remove suggesting for float to float conversion in [`cast_possible_truncation`]
style nit
New lint: detect unnecessary struct building
Fixes#10476.
Running this lint on the top 500 crates produced one hit (in `rust-lang/rust-bindgen`) and [a PR has been submitted there](https://github.com/rust-lang/rust-bindgen/pull/2440).
changelog: [`unnecessary_struct_initialization`]: new lint
The lint is very slow as it doesn't cache the deeply nested check for
the attribute. If we cache it, we can reduce the time spent on checking
`rustc_borrowck` from 28s to 9s, which is a nice improvement. In the
profile, the time inside `has_sig_drop_attr` goes from 66% to 0.2%,
which is a lot more reasonable.
See the PR for nice graphs.
Do not propose to simplify a not expression coming from a macro
Fixes#10523
changelog: FP [`nonminimal_bool`]: do not propose to change code coming from a macro
Do not propose to remove `async move` if variables are captured by ref
Fixes#10482
changelog: FP [`redundant_async_block`] Do not propose to remove `async move` if variables are captured by ref
a general type system cleanup
removes the helper functions `traits::fully_solve_X` as they add more complexity then they are worth. It's confusing which of these helpers should be used in which context.
changes the way we deal with overflow to always add depth in `evaluate_predicates_recursively`. It may make sense to actually fully transition to not have `recursion_depth` on obligations but that's probably a bit too much for this PR.
also removes some other small - and imo unnecessary - helpers.
r? types
The dogfood success condition was inverted in `tests/dogfood.rs`:
```rust
assert!(!failed_packages.is_empty(), …);
```
while instead the `failed_packages` collection must be empty:
```rust
assert!(failed_packages.is_empty(), …);
```
And indeed, several clippy lint source files were not clean and had to be
fixed in the process.
Issue function modifiers in the right order in manual_async_fn lint
Fixes#10450
changelog: [`manual_async_fn`] output function modifiers in correct order
fix `almost_swapped`: Ignore external macros
Fixes#10421 ; Related to #10499 (Fixing points *1* and *3* from #10421)
changelog: [`almost_swapped`]: Add a check to ignore external macros
Fix `almost_swapped` false positive (`let mut a = b; a = a`)
Fixes `2` in #10421
changelog: [`almost_swapped`]: Fix false positive when a variable is changed to itself. (`a = a`)
The documentation retained "vice versa" from the previous incarnation of
the lint but the lint itself no longer lints against manual `Hash`
implementations with a derived `PartialEq`.
I also adjusted the documentation for `PartialOrd`-`Ord` lint as "vice
versa" seemed a little confusing to me there (as to what it was refering
to exactly.)
Remove `identity_future` indirection
This was previously needed because the indirection used to hide some unexplained lifetime errors, which it turned out were related to the `min_choice` algorithm.
Removing the indirection also solves a couple of cycle errors, large moves and makes async blocks support the `#[track_caller]`annotation.
Fixes https://github.com/rust-lang/rust/issues/104826.
enhance [`ifs_same_cond`] to warn same immutable method calls as well
fixes: #10272
---
changelog: Enhancement: [`ifs_same_cond`]: Now also detects immutable method calls.
[#10350](https://github.com/rust-lang/rust-clippy/pull/10350)
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