[`manual_retain`]: Fix duplicate diagnostics
Relates to: #12379
The first lint guard executed in `LateLintPass::check_expr` was testing if the parent was of type `ExprKind::Assign`. This meant the lint emitted on both sides of the assignment operator when `check_expr` is called on either `Expr`. The guard in the fix only lints once when the `Expr` is of kind `Assign`.
changelog: Fix duplicate lint diagnostic emission from [`manual_retain`]
Add new `duplicated_attributes` lint
It's a lint idea that `@llogiq` gave me while reviewing another PR.
There are some limitations, in particular for the "output". Initially I wanted to make it possible for directly lint against the whole attribute if its parts were all duplicated, but then I realized that the output would be chaotic if the duplicates were coming from different attributes, so I preferred to go to the simplest way and simply emit a warning for each entry. Not the best, but makes the implementation much easier.
Another limitation is that `cfg_attr` would be a bit more tricky to implement because we need to check if two `cfg` sets are exactly the same. I added a FIXME and will likely come back to it later.
And finally, I updated the `cargo dev update_lints` command because the generated `tests/ui/rename.rs` file was emitting the `duplicated_attributes` lint, so I allowed this lint inside it to prevent it from working.
changelog: Add new `duplicated_attributes` lint
Fix dependency specifications
As Clippy lacks `Cargo.lock`, it makes sense to test its dependency specifications with [direct-minimal-versions](https://doc.rust-lang.org/cargo/reference/unstable.html#direct-minimal-versions). This can be done with the following addition to `.cargo/config.toml`.
```toml
[unstable]
direct-minimal-versions = true
```
* `tempfile` 3.3 is required by `clippy_lints`.
* `regex` 1.5.5 is required by `ui_test` 0.22.2.
* `quote` 1.0.25 is required by `syn` 2.0.0.
* `serde` 1.0.145 is required by `toml` 0.7.3.
changelog: none
[`single_match`]: Fix duplicate diagnostics
Relates to #12379
edit two test file
`tests/ui/single_match_else.rs`
`tests/ui/single_match.rs`
those two test file point to the same lint
---
changelog: [`single_match`] Fix duplicate diagnostics
[`seek_from_current`]: readability improvements
fixes#12457.
---
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`seek_from_current`]: readability improvements
add documentation to the `span_lint_hir` functions
As far as I could tell, these weren't documented anywhere, and since this is sometimes needed over `span_lint` for `#[allow]` attrs to work, I thought I would add a little bit of documentation.
When I started with clippy development, I also had no idea what these functions were for.
changelog: none
Add new `manual_unwrap_or_default` lint
This adds a new lint checking if a `match` or a `if let` can be replaced with `unwrap_or_default`.
----
changelog: Add new [`manual_unwrap_or_default`] lint
Add new lint `zero_repeat_side_effects`
Fixes https://github.com/rust-lang/rust-clippy/issues/6439
Adds a new `suspicious` lint zero_repeat_side_effects. This lint warns the user when initializing an array or `Vec` using the `Repeat` syntax, i.e., `[x; y]`. If `x` is an `Expr::Call/MethodCall` or contains an `Expr::Call/MethodCall` and `y` is zero, then there is a chance that the internal call can produce side effects, such as printing to console, which is not very obvious.
This lint warns against this and instead suggests to separate out the function call and the array/Vec initialization.
changelog: Add new lint `zero_repeat_side_effects`
use `span_lint_hir` instead of `span_lint` in more lints
Decided to grep for `check_(fn|block)` and look where `span_lint` is used, since some lints lint will then emit a lint on a statement or expression in that function, which would use the wrong lint level attributes
The `LintContext` keeps track of the last entered HIR node that had any attributes, and uses those (and its parents) for figuring out the lint level when a lint is emitted
However, this only works when we actually emit a lint at the same node as the `check_*` function we are in.
If we're in `check_fn` and we emit a lint on a statement within that function, then there is no way to allow the lint only for that one statement (if `span_lint` is used). It would only count allow attributes on the function
changelog: [`needless_return`]: [`useless_let_if_seq`]: [`mut_mut`]: [`read_zero_byte_vec`]: [`unused_io_amount`]: [`unused_peekable`]: now respects `#[allow]` attributes on the affected statement instead of only on the enclosing block or function
[`mut_mut`]: Fix duplicate diags
Relates to #12379
The `mut_mut` lint produced two diagnostics for each `mut mut` pattern in `ty` inside `block`s because `MutVisitor::visit_ty` was called from `MutMut::check_ty` and `MutMut::check_block` independently. This PR fixes the issue.
---
changelog: [`mut_mut`]: Fix duplicate diagnostics
New lint `const_is_empty`
This lint detects calls to `.is_empty()` on an entity initialized from a string literal and flag them as suspicious. To avoid triggering on macros called from generated code, it checks that the `.is_empty()` receiver, the call itself and the initialization come from the same context.
Fixes#12307
changelog: [`const_is_empty`]: new lint
fix [`missing_docs_in_private_items`] on some proc macros
fixes: #12197
---
changelog: [`missing_docs_in_private_items`] support manually search for docs as fallback method
Don't lint `redundant_field_names` across macro boundaries
Fixes#12426
The `field.span.eq_ctxt(field.ident.span)` addition is the relevant line for the bugfix
The current implementation checks that the field's name and the path are in the same context by comparing the idents, but not that the two are in the same context as the entire field itself, so in local macros `SomeStruct { $ident: $ident }` would get linted
changelog: none
Remove double expr lint
Related to #12379.
Previously the code manually checked nested binop exprs in unary exprs, but those were caught anyway by `check_expr`. Removed that code path, the path is used in the tests.
---
changelog: [`nonminimal_bool`] Remove duplicate output on nested Binops in Unary exprs.
Add `assigning_clones` lint
This PR is a "revival" of https://github.com/rust-lang/rust-clippy/pull/10613 (with `@kpreid's` permission).
I tried to resolve most of the unresolved things from the mentioned PR:
1) The lint now checks properly if we indeed call the functions `std::clone::Clone::clone` or `std::borrow::ToOwned::to_owned`.
2) It now supports both method and function (UFCS) calls.
3) A heuristic has been added to decide if the lint should apply. It will only apply if the type on which the method is called has a custom implementation of `clone_from/clone_into`. Notably, it will not trigger for types that use `#[derive(Clone)]`.
4) `Deref` handling has been (hopefully) a bit improved, but I'm not sure if it's ideal yet.
I also added a bunch of additional tests.
There are a few things that could be improved, but shouldn't be blockers:
1) When the right-hand side is a function call, it is transformed into e.g. `::std::clone::Clone::clone(...)`. It would be nice to either auto-import the `Clone` trait or use the original path and modify it (e.g. `clone::Clone::clone` -> `clone::Clone::clone_from`). I don't know how to modify the `QPath` to do that though.
2) The lint currently does not trigger when the left-hand side is a local variable without an initializer. This is overly conservative, since it could trigger when the variable has no initializer, but it has been already initialized at the moment of the function call, e.g.
```rust
let mut a;
...
a = Foo;
...
a = b.clone(); // Here the lint should trigger, but currently doesn't
```
These cases probably won't be super common, but it would be nice to make the lint more precise. I'm not sure how to do that though, I'd need access to some dataflow analytics or something like that.
changelog: new lint [`assigning_clones`]
[`misrefactored_assign_op`]: Fix duplicate diagnostics
Relate to #12379
The following diagnostics appear twice
```
--> tests/ui/assign_ops2.rs:26:5
|
LL | a *= a * a;
| ^^^^^^^^^^
|
help: did you mean `a = a * a` or `a = a * a * a`? Consider replacing it with
```
because `a` (lhs) appears in both left operand and right operand in the right hand side.
This PR fixes the issue so that if a diagnostic is created for an operand, the check of the other operand will be skipped. It's fine because the result is always the same in the affected operators.
changelog: [`misrefactored_assign_op`]: Fix duplicate diagnostics
Don't emit "missing backticks" lint if the element is wrapped in `<code>` HTML tags
Fixes#9473.
changelog: Don't emit "missing backticks" lint if the element is wrapped in `<code>` HTML tags
