[`map_entry`]: call the visitor on the local's `else` block
Fixes#12489
The lint already has all the logic it needs for figuring out if it can or can't suggest a closure if it sees control flow expressions like `break` or `continue`, but it was ignoring the local's else block, which meant that it didn't see the `return None;` in a `let..else`.
changelog: [`map_entry`]: suggest `if let` instead of a closure when `return` expressions exist in the else block of a `let..else`
new restriction lint: `integer_division_remainder_used`
Fixes https://github.com/rust-lang/rust-clippy/issues/12391
Introduces a restriction lint which disallows the use of `/` and `%` operators on any `Int` or `Uint` types (i.e., any that use the default `Div` or `Rem` trait implementations). Custom implementations of these traits are ignored.
----
changelog: Add new restriction lint [`integer_division_remainder_used`]
[`option_option`]: Fix duplicate diagnostics
Relates to #12379
This `option_option` lint change skips checks against `ty`s inside `field_def`s defined by external macro to prevent duplicate diagnostics to the same span `ty` by multiple `Struct` definitions.
---
changelog: [`option_option`]: Fix duplicate diagnostics
move `readonly_write_lock` to perf
[There haven't been any issues](https://github.com/rust-lang/rust-clippy/issues?q=is%3Aissue+readonly_write_lock) since its creation and it's a pretty useful lint I think, so I'd say it's worth giving it a try?
Did a lintcheck run on 300 crates with no results, but I guess `RwLock` is usually not something that's used much in libraries.
changelog: move [`readonly_write_lock`] to perf (now warn-by-default)
fix [`dbg_macro`] FN when dbg is inside some complex macros
fixes: #12131
It appears that [`root_macro_call_first_node`] only detects `println!` in the following example:
```rust
println!("{:?}", dbg!(s));
```
---
changelog: fix [`dbg_macro`] FN when `dbg` is inside some complex macros
(re-opening b'cuz bors doesn't like my previous one)
fix span calculation for non-ascii in `needless_return`
Fixes#12491
Probably fixes#12328 as well, but that one has no reproducer, so 🤷
The bug was that the lint used `rfind()` for finding the byte index of the start of the previous non-whitespace character:
```
// abc\n return;
^
```
... then subtracting one to get the byte index of the actual whitespace (the `\n` here).
(Subtracting instead of adding because it treats this as the length from the `return` token to the `\n`)
That's correct for ascii, like here, and will get us to the `\n`, however for non ascii, the `c` could be multiple bytes wide, which would put us in the middle of a codepoint if we simply subtract 1 and is what caused the ICE.
There's probably a lot of ways we could fix this.
This PR changes it to iterate backwards using bytes instead of characters, so that when `rposition()` finally finds a non-whitespace byte, we *know* that we've skipped exactly 1 byte. This was *probably*(?) what the code was intending to do
changelog: Fix ICE in [`needless_return`] when previous line end in a non-ascii character
[`unused_enumerate_index`]: trigger on method calls
The lint used to check for patterns looking like:
```rs
for (_, x) in some_iter.enumerate() {
// Index is ignored
}
```
This commit further checks for chained method calls constructs where we
can detect that the index is unused. Currently, this checks only for the
following patterns:
```rs
some_iter.enumerate().map_function(|(_, x)| ..)
let x = some_iter.enumerate();
x.map_function(|(_, x)| ..)
```
where `map_function` is one of `all`, `any`, `filter_map`, `find_map`,
`flat_map`, `for_each` or `map`.
Fixes#12411.
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`unused_enumerate_index`]: add detection for method chains such as `iter.enumerate().map(|(_, x)| x)`
Prior to this change, it might be that the lint would remove an explicit
type that was necessary for the type system to keep track of types.
This should be the last change that prevented this lint to be machine
applicable.
Don't emit `doc_markdown` lint for missing backticks if it's inside a quote
Fixes#10262.
changelog: Don't emit `doc_markdown` lint for missing backticks if it's inside a quote
[`use_self`]: Make it aware of lifetimes
Have the lint trigger even if `Self` has generic lifetime parameters.
```rs
impl<'a> Foo<'a> {
type Item = Foo<'a>; // Can be replaced with Self
fn new() -> Self {
Foo { // No lifetime, but they are inferred to be that of Self
// Can be replaced as well
...
}
}
// Don't replace `Foo<'b>`, the lifetime is different!
fn eq<'b>(self, other: Foo<'b>) -> bool {
..
}
```
Fixes#12381
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`use_self`]: Have the lint trigger even if `Self` has generic lifetime parameters
The lint used to check for patterns looking like:
```rs
for (_, x) in some_iter.enumerate() {
// Index is ignored
}
```
This commit further checks for chained method calls constructs where we
can detect that the index is unused. Currently, this checks only for the
following patterns:
```rs
some_iter.enumerate().map_function(|(_, x)| ..)
let x = some_iter.enumerate();
x.map_function(|(_, x)| ..)
```
where `map_function` is one of `all`, `any`, `filter_map`, `find_map`,
`flat_map`, `for_each` or `map`.
Fixes#12411.
lint when calling the blanket `Into` impl from a `From` impl
Closes#11150
```
warning: function cannot return without recursing
--> x.rs:9:9
|
9 | / fn from(value: f32) -> Self {
10 | | value.into()
11 | | }
| |_________^
|
note: recursive call site
--> x.rs:10:13
|
10 | value.into()
| ^^^^^^^^^^^^
```
I'm also thinking that we can probably generalize this lint to #11032 at some point (instead of hardcoding a bunch of impls), like how rustc's `unconditional_recursion` works, at least up to one indirect call, but this still seems useful for now :)
I've also noticed that we use `fn_def_id` in a bunch of lints and then try to get the node args of the call in a separate step, so I made a helper function that does both in one. I intend to refactor a bunch of uses of `fn_def_id` to use this later
I can add more test cases, but this is already using much of the same logic that exists for the other impls that this lint looks for (e.g. making sure that there are no conditional returns).
changelog: [`unconditional_recursion`]: emit a warning inside of `From::from` when unconditionally calling the blanket `.into()` impl
Move `iter_nth` to `style`, add machine applicable suggestion
There's no `O(n)` involved with `.iter().nth()` on the linted types since the iterator implementations provide `nth` and/or `advance_by` that operate in `O(1)`
For slice iterators the codegen is equivalent, `VecDeque`'s iterator seems to codegen differently but that doesn't seem significant enough to keep it as a perf lint
changelog: [`iter_nth`] Move to `style`
r? `@flip1995`
[`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
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
[`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
