When the 'early' and 'late' visitors visit an attribute target, they
activate any lint attributes (e.g. `#[allow]`) that apply to it.
This can affect warnings emitted on sibiling attributes. For example,
the following code does not produce an `unused_attributes` for
`#[inline]`, since the sibiling `#[allow(unused_attributes)]` suppressed
the warning.
```rust
trait Foo {
#[allow(unused_attributes)] #[inline] fn first();
#[inline] #[allow(unused_attributes)] fn second();
}
```
However, we do not do this for statements - instead, the lint attributes
only become active when we visit the struct nested inside `StmtKind`
(e.g. `Item`).
Currently, this is difficult to observe due to another issue - the
`HasAttrs` impl for `StmtKind` ignores attributes for `StmtKind::Item`.
As a result, the `unused_doc_comments` lint will never see attributes on
item statements.
This commit makes two interrelated fixes to the handling of inert
(non-proc-macro) attributes on statements:
* The `HasAttr` impl for `StmtKind` now returns attributes for
`StmtKind::Item`, treating it just like every other `StmtKind`
variant. The only place relying on the old behavior was macro
which has been updated to explicitly ignore attributes on item
statements. This allows the `unused_doc_comments` lint to fire for
item statements.
* The `early` and `late` lint visitors now activate lint attributes when
invoking the callback for `Stmt`. This ensures that a lint
attribute (e.g. `#[allow(unused_doc_comments)]`) can be applied to
sibiling attributes on an item statement.
For now, the `unused_doc_comments` lint is explicitly disabled on item
statements, which preserves the current behavior. The exact locatiosn
where this lint should fire are being discussed in PR #78306
We also update the documentation to note that the remediations are
different for `std` and `no_std` crates.
Signed-off-by: Joe Richey <joerichey@google.com>
Identical arguments on assert macro family
Lint when identical args are used on `assert_eq!`, `debug_assert_eq!`, `assert_ne!` and `debug_assert_ne!` macros.
Added to the lint `eq_op`.
Common functions added to `utils/higher.rs`
Fixes: #3574Fixes: #4694
changelog: Lint on identical args when calling `assert_eq!`, `debug_assert_eq!`, `assert_ne!` and `debug_assert_ne!` macros
BTreeMap: refactor Entry out of map.rs into its own file
btree/map.rs is approaching the 3000 line mark, splitting out the entry
code buys about 500 lines of headroom.
I've created this PR because the changes I've made in #77438 will push `map.rs` over the 3000 line limit and cause tidy to complain.
I picked `Entry` to factor out because it feels less tightly coupled to the rest of `BTreeMap` than the various iterator implementations.
Related: #60302
Sync from rust
Fix rustc breakage by running:
```rust
git subtree push -P src/tools/clippy git@github.com:josephlr/rust-clippy sync-from-rust
```
and then adding a commit that runs `cargo dev fmt`
---
changelog: none
The wrapper type led to tons of target.target
across the compiler. Its ptr_width field isn't
required any more, as target_pointer_width
is already present in parsed form.
Fix two ICEs caused by ty.is_{sized,freeze}
Fixes#6153
Properly fixes#6139
The test case in #6153 is kind of weird. Even removing one of the arguments of the `foo` function prevented the ICE. I think this test case is actually minimal.
changelog: none
Ref style link false positive
This PR does not fix#5834, but it records the problematic link text as a **known problem** inside `doc_markdown` lint.
r? `@flip1995`
- [ ] Followed [lint naming conventions][lint_naming]
- [ ] Added passing UI tests (including committed `.stderr` file)
- [x] `cargo test` passes locally
- [x] Executed `cargo dev update_lints`
- [ ] Added lint documentation
- [x] Run `cargo dev fmt`
---
*Please keep the line below*
changelog: Document problematic link text style as known problem for `doc_markdown`
Expands `manual_memcpy` to lint ones with loop counters
Closes#1670
This PR expands `manual_memcpy` to lint ones with loop counters as described in https://github.com/rust-lang/rust-clippy/issues/1670#issuecomment-293280204
Although the current code is working, I have a couple of questions and concerns.
~~Firstly, I manually implemented `Clone` for `Sugg` because `AssocOp` lacks `Clone`. As `AssocOp` only holds an enum, which is `Copy`, as a value, it seems `AssocOp` can be `Clone`; but, I was not sure where to ask it. Should I make a PR to `rustc`?~~ The [PR]( https://github.com/rust-lang/rust/pull/73629) was made.
Secondly, manual copying with loop counters are likely to trigger `needless_range_loop` and `explicit_counter_loop` along with `manual_memcpy`; in fact, I explicitly allowed them in the tests. Is there any way to disable these two lints when a code triggers `manual_memcpy`?
And, another thing I'd like to note is that `Sugg` adds unnecessary parentheses when expressions with parentheses passed to its `hir` function, as seen here:
```
error: it looks like you're manually copying between slices
--> $DIR/manual_memcpy.rs:145:14
|
LL | for i in 3..(3 + src.len()) {
| ^^^^^^^^^^^^^^^^^^ help: try replacing the loop by: `dst[3..((3 + src.len()))].clone_from_slice(&src[..((3 + src.len()) - 3)])
```
However, using the `hir` function is needed to prevent the suggestion causing errors when users use bitwise operations; and also this have already existed, for example: `verbose_bit_mask`. Thus, I think this is fine.
changelog: Expands `manual_memcpy` to lint ones with loop counters
Preserve raw strs for: format!(s) to s.to_string() lint
fixes#6142
clippy::useless_format will keep the source's string (after converting {{ and }} to { and }) when suggesting a change from format!() to .to_string() usage. Ie:
| let s = format!(r#""hello {{}}""#);
| ^^^^^^^^^^^^^^^^^^^^^ help: consider using `.to_string()`: `r#""hello {}""#.to_string()`
changelog: [`useless_format`]: preserve raw string literals when no arguments to `format!()` are provided.
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
clippy_lints: Do not warn against Box parameter in C FFI
changelog: [`boxed_local`]: don't lint in `extern fn` arguments
Fixes#5542.
When using C FFI, to handle pointers in parameters it is needed to
declare them as `Box` in its Rust-side signature. However, the current
linter warns against the usage of Box stating that "local variable
doesn't need to be boxed here".
This commit fixes it by ignoring functions whose Abi is C.
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
Fix unicode regexen with bytes::Regex
fixes#6005
The rationale for this is that since we wrote that lint, `bytes::Regex` was extended to be able to use unicode character classes.
---
changelog: [`invalid_regex`]: allow unicode character classes in bytes regex.
Fixes#5542.
When using C FFI, to handle pointers in parameters it is needed to
declare them as `Box` in its Rust-side signature. However, the current
linter warns against the usage of Box stating that "local variable
doesn't need to be boxed here".
This commit fixes it by ignoring functions whose Abi is Cdecl.
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
Fix LitKind's byte buffer to use refcounted slice
While working on adding a new lint for clippy (see https://github.com/rust-lang/rust-clippy/pull/6044) for avoiding shared ownership of "mutable buffer" types (such as using `Rc<Vec<T>>` instead of `Rc<[T]>`), I noticed a type exported from rustc_ast and used by clippy gets caught by the lint. This PR fixes the exported type.
This PR includes the actual change to clippy too, but I will open a PR directly against clippy for that part (although it will currently fail to build there).
unnecessary sort by: avoid dereferencing the suggested closure parameter
This change tries to simplify the solution for problematic cases but is less restrictive than #6006.
* We can't dereference shared references to non-Copy types, so the new suggestion does not do that. Note that this implies that the suggested closure parameter will be a reference.
* We can't take a reference to the closure parameter in the returned key, so we don't lint in those cases. This can happen either because the key borrows from the parameter (e.g. `|a| a.borrows()`), or because we suggest `|a| Reverse(a)`. If we did we would hit this error:
```
error: lifetime may not live long enough
--> /home/ebroto/src/ebroto-clippy/tests/ui/unnecessary_sort_by.fixed:19:25
|
19 | vec.sort_by_key(|b| Reverse(b));
| -- ^^^^^^^^^^ returning this value requires that `'1` must outlive `'2`
| ||
| |return type of closure is Reverse<&'2 isize>
| has type `&'1 isize`
error: aborting due to previous error
```
Note that Clippy does not currently have the (MIR-based) machinery necessary to check that what is borrowed is actually the closure parameter.
changelog: [`unnecessary_sort_by`]: avoid dereferencing the suggested closure parameter
Fixes#6001
Do not lint float fractions in `mistyped_literal_suffixes`
As suggested in https://github.com/rust-lang/rust-clippy/issues/4706#issuecomment-544797928, the fractional part is now ignored (the integer part is checked instead).
Fixes: #4706
changelog: `mistyped_literal_suffixes` no longer warns on the fractional part of a float (e.g. 713.23_64)
fix a false positive in two `interior_mutable_const` lints where a constant with enums gets linted
even if it uses a clearly unfrozen variant. Note that the code uses the MIR interpreter, which
the author of #3962 thought unlikely to be a solution. This might be over-engineering;
but, I think it's important to be able to work with the 'http' crate (#3825).
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.
Don't emit a lint for the suggestion leading to errors in `needless_range_loop`
Fix#5945
changelog: Don't emit a lint for the suggestion leading to errors in `needless_range_loop`
New Lint: disallowed_method
Fixes https://github.com/rust-lang/rust-clippy/issues/6073
I added a `disallowed_method` lint that works similar to `blacklisted_name`, e.g allows config-defined disallowed method calls.
This lint allows advanced users to patch in undesired method calls for specific projects. It basically uses the DefId of method calls and matches it to parsed strings. Is there an alternative approach that could use more easily digestible configuration strings?
All tests pass as expected except for a linting error on `ui/redundant_pattern_matching_option`, which I am not sure how to resolve since I don't think I changed anything affecting it.
changelog: Add disallowed_method lint to warn on user-defined method calls
Fix FP in `print_stdout`
Fix#6041
This lint shouldn't be emitted in `build.rs` as `println!` and `print!` are used for the build script.
changelog: none
Update Clippy
Bi-weekly Clippy update.
This includes a `Cargo.lock` update (d445493479711389f4dea3a0f433041077ba2088), so probably needs `rollup=never`.
r? `@Manishearth`
Allow a unique name to be assigned to dataflow graphviz output
Previously, if the same analysis were invoked multiple times in a single compilation session, the graphviz output for later runs would overwrite that of previous runs. Allow callers to add a unique identifier to each run so this can be avoided.
Revert: or_fun_call should lint calls to `const fn`s with no args
The changes in #5889 and #5984 were done under the incorrect assumption that a `const fn` with no args was guaranteed to be evaluated at compile time. A `const fn` is only guaranteed to be evaluated at compile time if it's inside a const context (the initializer of a `const` or a `static`).
See this [zulip conversation](https://rust-lang.zulipchat.com/#narrow/stream/122651-general/topic/Common.20misconception.3A.20.60const.20fn.60.20and.20its.20effect.20on.20codegen/near/208059113) for more details on this common misconception.
Given that none of the linted methods by `or_fun_call` can be called in const contexts, the lint should make no exceptions.
changelog: [`or_fun_call`] lints again calls to `const fn` with no args
Fix a FP in `explicit_counter_loop`
Fixes#4677 and #6074
Fix a false positive in `explicit_counter_loop` where the loop counter is used after incremented, adjust the test so that counters are incremented at the end of the loop and add the test for this false positive.
---
changelog: Fix a false positive in `explicit_counter_loop` where the loop counter is used after incremented
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
Fix a false positive in `explicit_counter_loop` where the loop counter is used after incremented,
adjust the test so that counters are incremented at the end of the loop
and add the test for this false positive.
Stabilize some Result methods as const
Stabilize the following methods of Result as const:
- `is_ok`
- `is_err`
- `as_ref`
A test is also included, analogous to the test for `const_option`.
These methods are currently const under the unstable feature `const_result` (tracking issue: #67520).
I believe these methods to be eligible for stabilization because of the stabilization of #49146 (Allow if and match in constants) and the trivial implementations, see also: [PR#75463](https://github.com/rust-lang/rust/pull/75463) and [PR#76135](https://github.com/rust-lang/rust/pull/76135).
Note: these methods are the only methods currently under the `const_result` feature, thus this PR results in the removal of the feature.
Related: #76225
* stop linting associated types and generic type parameters
* start linting ones in trait impls
whose corresponding definitions in the traits are generic
* remove the `is_copy` check
as presumably the only purpose of it is to allow
generics with `Copy` bounds as `Freeze` is internal
and generics are no longer linted
* remove the term 'copy' from the tests
as being `Copy` no longer have meaning
option_if_let_else - distinguish pure from impure else expressions
Addresses partially #5821.
changelog: improve the lint `option_if_let_else`. Suggest `map_or` or `map_or_else` based on the else expression purity.
Extend invalid_atomic_ordering for compare_exchange{,_weak} and fetch_update
changelog: The invalid_atomic_ordering lint can now detect misuse of `compare_exchange`, `compare_exchange_weak`, and `fetch_update`.
---
I was surprised not to find an issue or existing support here, since these are the functions which are always hardest to get the ordering right on for me (as the allowed orderings for `fail` depend on the `success` parameter).
I believe this lint now covers all atomic methods which care about their ordering now, but I could be wrong.
Hopefully I didn't forget to do anything for the PR!
{print,write}-with-newline: do not suggest empty format string
changelog: do not suggest empty format strings in `print-with-newline` and `write-with-newline`
clarify margin of error in wording of float comparison operator lint messages
fixes#6040
changelog: change wording of float comparison operator to make margin of error less ambiguous
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
Attach tokens to all AST types used in `Nonterminal`
We perform token capturing when we have outer attributes (for nonterminals that support attributes - e.g. `Stmt`), or when we parse a `Nonterminal` for a `macro_rules!` argument. The full list of `Nonterminals` affected by this PR is:
* `NtBlock`
* `NtStmt`
* `NtTy`
* `NtMeta`
* `NtPath`
* `NtVis`
* `NtLiteral`
Of these nonterminals, only `NtStmt` and `NtLiteral` (which is actually just an `Expr`), support outer attributes - the rest only ever have token capturing perform when they match a `macro_rules!` argument.
This makes progress towards solving https://github.com/rust-lang/rust/issues/43081 - we now collect tokens for everything that might need them. However, we still need to handle `#[cfg]`, inner attributes, and misc pretty-printing issues (e.g. #75734)
I've separated the changes into (mostly) independent commits, which could be split into individual PRs for each `Nonterminal` variant. The purpose of having them all in one PR is to do a single Crater run for all of them.
Most of the changes in this PR are trivial (adding `tokens: None` everywhere we construct the various AST structs). The significant changes are:
* `ast::Visibility` is changed from `type Visibility = Spanned<VisibilityKind>` to a `struct Visibility { kind, span, tokens }`.
* `maybe_collect_tokens` is made generic, and used for both `ast::Expr` and `ast::Stmt`.
* Some of the statement-parsing functions are refactored so that we can capture the trailing semicolon.
* `Nonterminal` and `Expr` both grew by 8 bytes, as some of the structs which are stored inline (rather than behind a `P`) now have an `Option<TokenStream>` field. Hopefully the performance impact of doing this is negligible.
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
Improve the "known problems" section of `interior_mutable_key`
* Remove the mention to `Rc` and `Arc` as these are `Freeze` (despite my intuition) so the lint correctly handles already.
* Instead, explain what could cause a false positive, and mention `bytes` as an example.
---
changelog: Improved the "known problems" section of `interior_mutable_key`
improve the suggestion of the lint `unit-arg`
Fixes#5823Fixes#6015
Changes
```
help: move the expression in front of the call...
|
3 | g();
|
help: ...and use a unit literal instead
|
3 | o.map_or((), |i| f(i))
|
```
into
```
help: move the expression in front of the call and replace it with the unit literal `()`
|
3 | g();
| o.map_or((), |i| f(i))
|
```
changelog: improve the suggestion of the lint `unit-arg`
Add CONST_ITEM_MUTATION lint
Fixes#74053Fixes#55721
This PR adds a new lint `CONST_ITEM_MUTATION`.
Given an item `const FOO: SomeType = ..`, this lint fires on:
* Attempting to write directly to a field (`FOO.field = some_val`) or
array entry (`FOO.array_field[0] = val`)
* Taking a mutable reference to the `const` item (`&mut FOO`), including
through an autoderef `FOO.some_mut_self_method()`
The lint message explains that since each use of a constant creates a
new temporary, the original `const` item will not be modified.
* Remove the mention to `Rc` and `Arc` as these are `Freeze`
so the lint correctly handles already.
* Instead, explain what could cause a false positive,
and mention `bytes` as an example.
We no longer lint assignments to const item fields in the
`temporary_assignment` lint, since this is now covered by the
`CONST_ITEM_MUTATION` lint.
Additionally, we `#![allow(const_item_mutation)]` in the
`borrow_interior_mutable_const.rs` test. Clippy UI tests are run with
`-D warnings`, which seems to cause builtin lints to prevent Clippy
lints from running.
Support dataflow problems on arbitrary lattices
This PR implements last of the proposed extensions I mentioned in the design meeting for the original dataflow refactor. It extends the current dataflow framework to work with arbitrary lattices, not just `BitSet`s. This is a prerequisite for dataflow-enabled MIR const-propagation. Personally, I am skeptical of the usefulness of doing const-propagation pre-monomorphization, since many useful constants only become known after monomorphization (e.g. `size_of::<T>()`) and users have a natural tendency to hand-optimize the rest. It's probably worth exprimenting with, however, and others have shown interest cc `@rust-lang/wg-mir-opt.`
The `Idx` associated type is moved from `AnalysisDomain` to `GenKillAnalysis` and replaced with an associated `Domain` type that must implement `JoinSemiLattice`. Like before, each `Analysis` defines the "bottom value" for its domain, but can no longer override the dataflow join operator. Analyses that want to use set intersection must now use the `lattice::Dual` newtype. `GenKillAnalysis` impls have an additional requirement that `Self::Domain: BorrowMut<BitSet<Self::Idx>>`, which effectively means that they must use `BitSet<Self::Idx>` or `lattice::Dual<BitSet<Self::Idx>>` as their domain.
Most of these changes were mechanical. However, because a `Domain` is no longer always a powerset of some index type, we can no longer use an `IndexVec<BasicBlock, GenKillSet<A::Idx>>>` to store cached block transfer functions. Instead, we use a boxed `dyn Fn` trait object. I discuss a few alternatives to the current approach in a commit message.
The majority of new lines of code are to preserve existing Graphviz diagrams for those unlucky enough to have to debug dataflow analyses. I find these diagrams incredibly useful when things are going wrong and considered regressing them unacceptable, especially the pretty-printing of `MovePathIndex`s, which are used in many dataflow analyses. This required a parallel `fmt` trait used only for printing dataflow domains, as well as a refactoring of the `graphviz` module now that we cannot expect the domain to be a `BitSet`. Some features did have to be removed, such as the gen/kill display mode (which I didn't use but existed to mirror the output of the old dataflow framework) and line wrapping. Since I had to rewrite much of it anyway, I took the opportunity to switch to a `Visitor` for printing dataflow state diffs instead of using cursors, which are error prone for code that must be generic over both forward and backward analyses. As a side-effect of this change, we no longer have quadratic behavior when writing graphviz diagrams for backward dataflow analyses.
r? `@pnkfelix`
Fix FP in `same_item_push`
Don't emit a lint when the pushed item doesn't have Clone trait
Fix#5979
changelog: Fix FP in `same_item_push` not to emit a lint when the pushed item doesn't have Clone trait
useless_attribute: Permit wildcard_imports and enum_glob_use
Fixes#5918
changelog: `useless_attribute`: Permit `wildcard_imports` and `enum_glob_use` on `use` items
default_trait_access: Fix wrong suggestion
https://github.com/rust-lang/rust-clippy/issues/5975#issuecomment-683751131
> I think the underlying problem is clippy suggests code with complete parameters, not clippy triggers this lint even for complex types. AFAIK, If code compiles with `Default::default`, it doesn't need to specify any parameters, as type inference is working. (So, in this case, `default_trait_access` should suggest `RefCell::default`.)
Fixes#5975Fixes#5990
changelog: `default_trait_access`: fixed wrong suggestion
Add a lint for an async block/closure that yields a type that is itself awaitable.
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.
});
See the two XXXkhuey comments and the unfixed `_l` structure for things that need more thought.
*Please keep the line below*
changelog: none
or_fn_call: ignore nullary associated const fns
The fix in #5889 was missing associated functions.
changelog: Ignore also `const fn` methods in [`or_fun_call`]
Fixes#5693
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.
});
Fix FP in `to_string_in_display`
Don't emit a lint when `.to_string()` on anything that is not `self`
Fix#5967
changelog: Fix FP in `to_string_in_display` when calling `.to_string()` on anything that is not `self`
Corrects the float_equality_without_abs lint
Fixes an issue in the `float_equality_without_abs` lint. The lint suggestion was configured in a way that it lints the whole error and not just the subtraction part. In the current configuration the lint would suggest to change the expression in a wrong way, e.g.
```rust
let _ = (a - b) < f32::EPSILON; // before
let _ = (a - b).abs(); // after
```
This was dicovered by @flip1995. (See discussion of PR #5952).
Also the suggestion is now formatted via `utils::sugg`.
changelog: none
Fix `let_and_return` bad suggestion
Add a cast to the suggestion when the return expression has adjustments.
These adjustments are lost when the suggestion is applied.
This is similar to the problem in issue #4437.
Closes#5729
changelog: Fix `let_and_return` bad suggestion
Fix fp in `borrow_interior_mutable_const`
fixes#5796
changelog: fix false positive in `borrow_interior_mutable_const` when referencing a field behind a pointer.
Fix incorrect suggestion when `clone_on_ref_ptr` is triggered in macros
In the lint `clone_on_ref_ptr`, if the `span` is in a macro, don't expand it for suggestion.
Fixes: #2076
changelog: none
r? @ebroto
Add a cast to the suggestion when the return expression has adjustments.
These adjustments are lost when the suggestion is applied.
This is similar to the problem in issue #4437.
Closes#5729
Don't lint if it has always inline attribute
Don't trigger the lint `trivially_copy_pass_by_ref` if it has `#[inline(always)]` attribute.
Note: I am not particularly familiar with `inline` impacts, so I implemented this the way that if only `#[inline]` attribute is here (without `always`), the lint will still trigger. Also, it will still trigger if it has `#[inline(never)]`.
Just tell me if it sounds too much conservative.
Fixes: #5876
changelog: none
Prelude imports are exempt from wildcard import warnings. Until now only
imports of the form
```
use ...::prelude::*;
```
were considered. This change makes it so that the segment `prelude` can
show up anywhere, for instance:
```
use ...::prelude::v1::*;
```
Fixes#5917
Fix false positive in `PRECEDENCE` lint
Extend the lint to handle chains of methods combined with unary negation.
Closes#5924
changelog: Fix false negative in `PRECEDENCE` lint
This extends PR #73293 to handle patterns (Pat). Unlike expressions,
patterns do not support custom attributes, so we only need to capture
tokens during macro_rules! argument parsing.
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;
}
```
Add unnecessary lazy evaluation lint
changelog: Add [`unnecessary_lazy_evaluations`] lint that checks for usages of `unwrap_or_else` and similar functions that can be simplified.
Closes#5715
should_impl_trait - ignore methods with lifetime params
Fixes: #5617
changelog: don't lint should_implement_trait when an `Iterator::next` case has explicit parameters
Fix: keep parenthesis for suggestion in `useless_conversion` lint
Note: this lint was previously named `identity_conversion`.
fixes: #4750
changelog: fix parenthesis for `useless_conversion` lint suggestion
Add the other overloadable operations to suspicious_arithmetic_impl
In #2268 I idly mused that the other user-overloadable operations could be added to this lint. Knowing that the lint was arguably incomplete was gnawing at the back of my mind, so I figured that I might as well make this PR, particularly given the change needed was so small.
changelog: Start warning on suspicious implementations of the `BitAnd`, `BitOr`, `BitXor`, `Rem`, `Shl`, and `Shr` traits.
In #2268 I idly mused that the other user-overloadable operations could be added to this lint. Knowing that the lint was arguably incomplete was gnawing at the back of my mind, so I figured that I might as well make this PR, particularly given the change needed was so small.
Miri: Renamed "undef" to "uninit"
Renamed remaining references to "undef" to "uninit" when referring to Miri.
Impacted directories are:
- `src/librustc_codegen_llvm/consts.rs`
- `src/librustc_middle/mir/interpret/`
- `src/librustc_middle/ty/print/pretty.rs`
- `src/librustc_mir/`
- `src/tools/clippy/clippy_lints/src/consts.rs`
Upon building Miri based on the new changes it was verified that no changes needed to be made with the Miri project.
Related issue #71193
make a bunch of lints texts adhere to rustc dev guide
According to the rustc-dev guide: "The text should be matter of fact and avoid capitalization and periods, unless multiple sentences are needed"
changelog: make some lint output adhere to the rustc-dev guide
enable #[allow(clippy::unsafe_derive_deserialize)]
Before this change this lint could not be allowed as the code we are checking is automatically generated.
changelog: Enable using the `allow` attribute on top of an ADT linted by [`unsafe_derive_deserialize`].
Fixes: #5789
Fix ICE in `loops` module
changelog: Fix ICE related to `needless_collect` when a call to `iter()` was not present.
I went for restoring the old suggestion of `next().is_some()` over `get(0).is_some()` given that `iter()` is not necessarily present (could be e.g. `into_iter()` or `iter_mut()`) and that the old suggestion could change semantics, e.g. a call to `filter()` could be present between `iter()` and the collect part.
Fixes#5872
Renamed remaining references to "undef" to "uninit" when referring to Miri.
Impacted directories are:
- src/librustc_codegen_llvm/consts.rs
- src/librustc_middle/mir/interpret/
- src/librustc_middle/ty/print/pretty.rs
- src/librustc_mir/
- src/tools/clippy/clippy_lints/src/consts.rs
Upon building Miri based on the new changes it was verified that no changes needed to be made with the Miri project.
Related issue #71193
By moving `{known,used}_attrs` from `SessionGlobals` to `Session`. This
means they are accessed via the `Session`, rather than via TLS. A few
`Attr` methods and `librustc_ast` functions are now methods of
`Session`.
All of this required passing a `Session` to lots of functions that didn't
already have one. Some of these functions also had arguments removed, because
those arguments could be accessed directly via the `Session` argument.
`contains_feature_attr()` was dead, and is removed.
Some functions were moved from `librustc_ast` elsewhere because they now need
to access `Session`, which isn't available in that crate.
- `entry_point_type()` --> `librustc_builtin_macros`
- `global_allocator_spans()` --> `librustc_metadata`
- `is_proc_macro_attr()` --> `Session`
try_err: Consider Try impl for Poll when generating suggestions
There are two different implementation of `Try` trait for `Poll` type:
`Poll<Result<T, E>>` and `Poll<Option<Result<T, E>>>`. Take them into
account when generating suggestions.
For example, for `Err(e)?` suggest either `return Poll::Ready(Err(e))` or
`return Poll::Ready(Some(Err(e)))` as appropriate.
Fixes#5855
changelog: try_err: Consider Try impl for Poll when generating suggestions
Add derive_ord_xor_partial_ord lint
Fix#1621
Some remarks:
This PR follows the example of the analogous derive_hash_xor_partial_eq lint where possible.
I initially tried using the `match_path` function to identify `Ord` implementation like the derive_hash_xor_partial_eq lint currently does, for `Hash` implementations but that didn't work.
Specifically, the structs at the top level were getting paths that matched `&["$crate", "cmp", "Ord"]` instead of `&["std", "cmp", "Ord"]`. While trying to figure out what to do instead I saw the comment at the top of [clippy_lints/src/utils/paths.rs](f5d429cd76/clippy_lints/src/utils/paths.rs (L5)) that mentioned [this issue](https://github.com/rust-lang/rust-clippy/issues/5393) and suggested to use diagnostic items instead of hardcoded paths whenever possible. I looked for a way to identify `Ord` implementations with diagnostic items, but (possibly because this was the first time I had heard of diagnostic items,) I was unable to find one.
Eventually I tried using `get_trait_def_id` and comparing `DefId` values directly and that seems to work as expected. Maybe there's a better approach however?
changelog: new lint: derive_ord_xor_partial_ord
Handle mapping to Option in `map_flatten` lint
Fixes#4496
The existing [`map_flatten`](https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten) lint suggests changing `expr.map(...).flatten()` to `expr.flat_map(...)` when `expr` is `Iterator`. This PR changes suggestion to `filter_map` instead of `flat_map` when mapping to `Option`, because it is more natural
Also here are some questions:
* If expression has type which implements `Iterator` trait (`match_trait_method(cx, expr, &paths::ITERATOR) == true`), how can I get type of iterator elements? Currently I use return type of closure inside `map`, but probably it is not good way
* I would like to change suggestion range to cover only `.map(...).flatten()`, that is from:
```
let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| 0..x).flatten().collect();
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `flat_map` instead: `vec![5_i8; 6].into_iter().flat_map
```
to
```
let _: Vec<_> = vec![5_i8; 6].into_iter().map(|x| 0..x).flatten().collect();
^^^^^^^^^^^^^^^^^^^^^^^^ help: try using `flat_map` instead: `.flat_map(|x| 0..x)`
```
Is it ok?
* Is `map_flatten` lint intentionally in `pedantic` category, or could it be moved to `complexity`?
changelog: Handle mapping to Option in [`map_flatten`](https://rust-lang.github.io/rust-clippy/master/index.html#map_flatten) lint
needless_collect: catch x: Vec<_> = iter.collect(); x.into_iter() ...
changelog: Expand the needless_collect lint as suggested in #5627 (WIP).
This PR is WIP because I can't figure out how to make the multi-part suggestion include its changes in the source code (the fixed is identical to the source, despite the lint making suggestions). Aside from that one issue, I think this should be good.
For consistency with `Attribute::has_name` which doesn't mark the attribute as used either.
Replace all uses of `check_name` with `has_name` outside of rustc
There are two different implementation of Try trait for Poll type;
Poll<Result<T, E>> and Poll<Option<Result<T, E>>>. Take them into
account when generating suggestions.
For example, for Err(e)? suggest either return Poll::Ready(Err(e)) or
return Poll::Ready(Some(Err(e))) as appropriate.
Fix FP for `suspicious_arithmetic_impl` from `suspicious_trait_impl` …
As discussed in #3215, the `suspicious_trait_impl` lint causes too many false positives, as it is complex to find out if binary operations are suspicious or not.
This PR restricts the number of binary operations to at most one, otherwise we don't lint.
This can be seen as very conservative, but at least FP can be reduced to bare minimum.
Fixes: #3215
changelog: limit the `suspicious_arithmetic_impl` lint to one binop, to avoid many FPs
Use `(std::)f64::EPSILON` in the examples as suggested in the lints
`float_cmp(_const)` suggests using `{f32|f64}::EPSILON` and it'd be great if the docs mentioned it.
changelog: none
This commit modifies the `substitute_normalize_and_test_predicates`
query, renaming it to `impossible_predicates` and only checking
predicates which do not require substs. By making this change,
polymorphization doesn't have to explicitly support vtables.
Signed-off-by: David Wood <david@davidtw.co>
Ignore not really redundant clones of ManuallyDrop
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
changelog: Ignore redundant clone lint for ManuallyDrop.
"Redundant" clones of `ManuallyDrop` are sometimes used for the side effect of
invoking the clone, without running the drop implementation of the inner type.
In other words, they aren't really redundant. For example, futures-rs crate:
```rust
#[allow(clippy::redundant_clone)] // The clone here isn't actually redundant.
unsafe fn increase_refcount<T: ArcWake>(data: *const ()) {
// Retain Arc, but don't touch refcount by wrapping in ManuallyDrop
let arc = mem::ManuallyDrop::new(Arc::<T>::from_raw(data as *const T));
// Now increase refcount, but don't drop new refcount either
let _arc_clone: mem::ManuallyDrop<_> = arc.clone();
}
```
Ignore redundant clone lint for ManuallyDrop.
Panic multiple args
changelog: Fixes bug with `panic` lint reported in #5767. I also did the same changes to the lints for `todo`, `unimplemented` and `unreachable`, so those lints should now also detect calls to those macros with a message.
Removing RHS snippet from SHADOW_UNRELATED message.
Fixes#5703
I am not sure if I reinvented the wheel here, but I could not really find a snippet function that did this truncation, so I created the function. Please tell me if there was a more obvious way to do this, I am new here. 😄
changelog: Truncates multi-line RHS in shadow_unrelated message if it has more than 5 lines.
improve advice in iter_nth_zero
fixes#5783
*Please keep the line below*
changelog: For iter_nth_zero, the "use .next()" replacement advice is on the last line of the code snippet, where it is vulnerable to truncation. Display that advice at the beginning instead.
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
Rename collapsable_if fix suggestion to "collapse nested if block"
The name "try" is confusing when shown as quick fix by rust-analyzer
changelog: Rename `collapsable_if` fix suggestion to "collapse nested if block"
The "use .next()" replacement advice is on the last line of the code snippet,
where it is vulnerable to truncation. Display that advice at the beginning
instead.
closes#5783
Fix out of bounds access by checking length equality BEFORE accessing by index.
Fixes#5780
changelog: fix out of bounds access in unnested_or_patterns lint.
Edit: I did not bother reducing a testcase from `librustc_typeck` crate but I can confirm that with the change the crash no longer occurs.
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
Some accuracy lints for floating point operations
This will add some lints for accuracy on floating point operations suggested by @clarfon in #2040 (fixes#2040).
These are the remaining lints:
- [x] x.powi(2) => x * x
- [x] x.logN() / y.logN() => x.logbase(y)
- [x] x.logbase(E) => x.log()
- [x] x.logbase(10) => x.log10()
- [x] x.logbase(2) => x.log2().
- [x] x * PI / 180 => x.to_radians()
- [x] x * 180 / PI => x.to_degrees()
- [x] (x + 1).log() => x.log_1p()
- [x] sqrt(x * x + y * y) => x.hypot(y)
changelog: Included some accuracy lints for floating point operations
new lint: match_like_matches_macro
Suggests using the `matches!` macro from `std` where appropriate.
`redundant_pattern_matching` has been moved into the `matches` pass to allow suppressing the suggestion where `is_some` and friends are a better replacement.
changelog: new lint: `match_like_matches_macro`
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.
single_match_else - single expr/stmt else block corner case
One approach to fix#3489.
See discussion in the issue.
changelog: single_match_else - single expr/stmt else block corner case fix
Rollup of 14 pull requests
Successful merges:
- #70563 ([rustdoc] Page hash handling)
- #73856 (Edit librustc_lexer top-level docs)
- #73870 (typeck: adding type information to projection)
- #73953 (Audit hidden/short code suggestions)
- #73962 (libstd/net/tcp.rs: #![deny(unsafe_op_in_unsafe_fn)])
- #73969 (mir: mark mir construction temporaries as internal)
- #73974 (Move A|Rc::as_ptr from feature(weak_into_raw) to feature(rc_as_ptr))
- #74067 (rustdoc: Restore underline text decoration on hover for FQN in header)
- #74074 (Fix the return type of Windows' `OpenOptionsExt::security_qos_flags`.)
- #74078 (Always resolve type@primitive as a primitive, not a module)
- #74089 (Add rust-analyzer to the build manifest)
- #74090 (Remove unused RUSTC_DEBUG_ASSERTIONS)
- #74102 (Fix const prop ICE)
- #74112 (Expand abbreviation in core::ffi description)
Failed merges:
r? @ghost
typeck: adding type information to projection
This commit modifies the Place as follow:
* remove 'ty' from ProjectionKind
* add type information into to Projection
* replace 'ty' in Place with 'base_ty'
* introduce 'ty()' in `Place` to return the final type of the `Place`
* introduce `ty_before_projection()` in `Place` to return the type of
a `Place` before i'th projection is applied
Closes https://github.com/rust-lang/project-rfc-2229/issues/5
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.)
This commit modifies the Place as follow:
* remove 'ty' from ProjectionKind
* add type information into to Projection
* replace 'ty' in Place with 'base_ty'
* introduce 'ty()' in `Place` to return the final type of the `Place`
* introduce `ty_before_projection()` in `Place` to return the type of
a `Place` before i'th projection is applied
Closes https://github.com/rust-lang/project-rfc-2229/issues/5
Rollup of 13 pull requests
Successful merges:
- #72620 (Omit DW_AT_linkage_name when it is the same as DW_AT_name)
- #72967 (Don't move cursor in search box when using arrows to navigate results)
- #73102 (proc_macro: Stop flattening groups with dummy spans)
- #73297 (Support configurable deny-warnings for all in-tree crates.)
- #73507 (Cleanup MinGW LLVM linkage workaround)
- #73588 (Fix handling of reserved registers for ARM inline asm)
- #73597 (Record span of `const` kw in GenericParamKind)
- #73629 (Make AssocOp Copy)
- #73681 (Update Chalk to 0.14)
- #73707 (Fix links in `SliceIndex` documentation)
- #73719 (emitter: column width defaults to 140)
- #73729 (disable collectionbenches for android)
- #73748 (Add code block to code in documentation of `List::rebase_onto`)
Failed merges:
r? @ghost
Record span of `const` kw in GenericParamKind
Context: this is needed for a fix of https://github.com/rust-lang/rustfmt/issues/4263,
which currently records the span of a const generic param incorrectly
because the location of the `const` kw is not known.
I am not sure how to add tests for this; any guidance in how to do so
would be appreciated 🙂
cmp_owned: handle when PartialEq is not implemented symmetrically
changelog: Handle asymmetrical implementations of PartialEq in [`cmp_owned`].
Fixes#4874
clone_on_copy - add machine applicability
Fix#4826.
Change the applicability of the lint clone_on_copy. Split a test file and run rustfix on the clone_on_copy part.
changelog: clone_on_copy - add machine applicability
Context: this is needed to fix https://github.com/rust-lang/rustfmt/issues/4263,
which currently records the span of a const generic param incorrectly
because the location of the `const` kw is not known.
I am not sure how to add tests for this; any guidance in how to do so
would be appreciated 🙂
#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.
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
Don't trigger while_let_on_iterator when the iterator is recreated every iteration
r? @phansch
Fixes#1654
changelog: Fix false positive in [`while_let_on_iterator`]
Downgrade match_bool to pedantic
I don't quite buy the justification in https://rust-lang.github.io/rust-clippy/. The justification is:
> It makes the code less readable.
In the Rust codebases I've worked in, I have found people were comfortable using `match bool` (selectively) to make code more readable. For example, initializing struct fields is a place where the indentation of `match` can work better than the indentation of `if`:
```rust
let _ = Struct {
v: {
...
},
w: match doing_w {
true => ...,
false => ...,
},
x: Nested {
c: ...,
b: ...,
a: ...,
},
y: if doing_y {
...
} else { // :(
...
},
z: ...,
};
```
Or sometimes people prefer something a bit less pithy than `if` when the meaning of the bool doesn't read off clearly from the condition:
```rust
if set.insert(...) {
... // ???
} else {
...
}
match set.insert(...) {
// set.insert returns false if already present
false => ...,
true => ...,
}
```
Or `match` can be a better fit when the bool is playing the role more of a value than a branch condition:
```rust
impl ErrorCodes {
pub fn from(b: bool) -> Self {
match b {
true => ErrorCodes::Yes,
false => ErrorCodes::No,
}
}
}
```
And then there's plain old it's-1-line-shorter, which means we get 25% more content on a screen when stacking a sequence of conditions:
```rust
let old_noun = match old_binding.is_import() {
true => "import",
false => "definition",
};
let new_participle = match new_binding.is_import() {
true => "imported",
false => "defined",
};
```
Bottom line is I think this lint fits the bill better as a pedantic lint; I don't think linting on this by default is justified.
changelog: Remove match_bool from default set of enabled lints
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
Fix issue #2907.
Update the "borrow box" lint to avoid recommending the following
conversion:
```
// Old
pub fn f(&mut Box<T>) {...}
// New
pub fn f(&mut T) {...}
```
Given a mutable reference to a box, functions may want to change
"which" object the Box is pointing at.
This change avoids recommending removing the "Box" parameter
for mutable references.
changelog: Don't trigger [`borrow_box`] lint on `&mut Box` references
Cleanup: `node_id` -> `hir_id`
This removes some more `node_id` terminology from Clippy and replaces one occurrence of `as_local_node_id` with `as_local_hir_id`, which should be doing the same for that particular case.
changelog: none
Update the "borrow box" lint to avoid recommending the following
conversion:
```
// Old
pub fn f(&mut Box<T>) {...}
// New
pub fn f(&mut T) {...}
```
Given a mutable reference to a box, functions may want to change
"which" object the Box is pointing at.
This change avoids recommending removing the "Box" parameter
for mutable references.
add lint futures_not_send
changelog: add lint futures_not_send
fixes#5379
~Remark: one thing that can (should?) still be improved is to directly include the error message from the `Send` check so that the programmer stays in the flow. Currently, getting the actual error message requires a restructuring of the code to make the `Send` constraint explicit.~
It now shows all unmet constraints for allowing the Future to be Send.
Fixes issue #4892.
First contribution here 😊 ! Do not hesitate to correct me.
This PR is related to issue #4892 .
# Summary
```rust
-literal.method_call(args)
```
The main idea is to not trigger `clippy::precedence` when the method call is an odd function.
# Example
```rust
// should trigger lint
let _ = -1.0_f64.abs() //precedence of method call abs() and neg ('-') is ambiguous
// should not trigger lint
let _ = -1.0_f64.sin() // sin is an odd function => -sin(x) = sin(-x)
```
# Theory
Rust allows following literals:
- char
- string
- integers
- floats
- byte
- bool
Only integers/floats implements the relevant `std::ops::Neg`.
Following odd functions are implemented on i[8-128] and/or f[32-64]:
- `asin`
- `asinh`
- `atan`
- `atanh`
- `cbrt`
- `fract`
- `round`
- `signum`
- `sin`
- `sinh`
- `tan`
- `tanh `
- `to_degrees`
- `to_radians`
# Implementation
As suggested by `flip1995` in [comment](https://github.com/rust-lang/rust-clippy/issues/4892#issuecomment-568249683), this PR add a whitelist of odd functions and compare method call to the the whitelist before triggering lint.
changelog: Don't trigger [`clippy::precedence`] on odd functions.
question_mark: don't add `as_ref()` for a call expression
If a call returns a `!Copy` value, it does so regardless of whether `as_ref()` is added. For example, `foo.into_option().as_ref()?` can be simplified to `foo.into_option()?`.
---
changelog: Improved `question_mark` lint suggestion so that it doesn't add redundant `as_ref()`
Do not lint in macros for match lints
Don't lint in macros for match lints, more precisely in `check_pat` and `check_local` where it was not the case.
changelog: none
fixes: #5362
large_enum_variant: Report sizes of variants
This reports the sizes of the largest and second-largest variants.
Closes#5459
changelog: `large_enum_variant`: Report the sizes of the largest and second-largest variants.
Disallow bit-shifting in integer_arithmetic
Make the `integer_arithmetic` lint detect all the operations that are defined as being capable of overflow in the [Rust Reference](https://doc.rust-lang.org/reference/expressions/operator-expr.html#overflow), by also linting for bit-shifting operations (`<<`, `>>`).
changelog: Disallow bit-shifting in `integer_arithmetic`
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
Add lint for explicit deref and deref_mut method calls
This PR adds the lint `explicit_deref_method` that suggests replacing `deref()` and `deref_mut()` with `&*a` and `&mut *a`.
It doesn't lint inside macros.
This PR is the continuation of #3258.
changelog: Add lint `explicit_deref_method`.
Fixes: #1566
Add lint for float in array comparison
Fixes#4277
changelog:
- Added new handler for expression of index kind (e.g. `arr[i]`). It returns a constant when both array and index are constant, or when the array is constant and all values are equal.
- Trigger float_cmp and float_cmp_const lint when comparing arrays. Allow for comparison when one of the arrays contains only zeros or infinities.
- Added appropriate tests for such cases.
Refactor: Use rustc's `match_def_path`
This replaces our match_def_path implementation with the rustc one.
Note that we can't just use it in all call sites because of the
`&[&str]` / `&[Symbol]` difference in Clippy/rustc.
changelog: none
This replaces our match_def_path implementation with the rustc one.
Note that we can't just use it in all call sites because of the
`&[&str]` / `&[Symbol]` difference in Clippy/rustc.
Make use of more diagnostic items
This makes use of some (not all) already existing diagnostic items. Specifically:
* 79982a2: `core::mem::uninitialized`, `core::mem::zeroed`, `alloc::sync::Arc`, `alloc::sync::Rc`
* 83874d0: `Option` and `Result`
cc #5393
changelog: none
Fixes#5405: redundant clone false positive with arrays
Check whether slice elements implement Copy before suggesting to drop
the clone method
changelog: add a check for slice indexing on redundant_clone lint
Update documentation for new_ret_no_self
changelog: Update documentation for lint new_ret_no_self to reflect that the return type must only contain `Self`, not be `Self`
The lint was changed to be more lenient than the documentation implies in PR #3338 (Related issue #3313)
Change the existing hex bit mask (`0x1111`) to a binary one (`0b1111`).
The former does not seem to have anything to do with trailing zeros and is
probably a typo.
This change adds a check to the `inconsistent_digit_grouping` to add a check for
NumericLiterals that follow the UUID format of 8-4-4-4-12.
If the NumericLiteral matches the UUID format, no further inconsistent grouping checks
will be performed.
Closes#5431
Check for clone-on-copy in argument positions
Earlier if arguments to method calls matched the above pattern they were
not reported. This patch ensures such arguments are checked as well.
Fixes#5436
changelog: apply clone_on_copy lint to func args as well
Earlier if arguments to method calls matched the above pattern they were
not reported. This patch ensures such arguments are checked as well.
Fixes#5436
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
Check fn header along with decl when suggesting to implement trait
When checking for functions that are potential candidates for trait
implementations check the function header to make sure modifiers like
asyncness, constness and safety match before triggering the lint.
Fixes#5413, #4290
changelog: check fn header along with decl for should_implement_trait
When checking for functions that are potential candidates for trait
implementations check the function header to make sure modifiers like
asyncness, constness and safety match before triggering the lint.
Fixes#5413, #4290
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
Fix update_lints
This fixes a bug in update_lints, where `internal` lints were not registered properly. This also cleans up some code. For example: The code generation functions no longer filter the lints the are given. This is now the task of the caller. This way, it is more obvious in the `replace_in_file` calls which lints will be included in which part of a file.
This also turns the lint modules private. There is no need for them to be public, since shared code should be in the utils module anyway.
And last but not least, this fixes the `register_lints` code generation, so also internal lints get registered.
changelog: none
