new lint: [`readonly_write_lock`]
Closes#8555
A new lint that catches `RwLock::write` calls to acquire a write lock only to read from it and not actually do any writes (mutations).
changelog: new lint: [`readonly_write_lock`]
Now `option_env_unwrap` warns even if a variable isn't set at compiletime
Fixes#10742
changelog: Fix false negative where `option_env_unwrap` wouldn't warn if the env variable isn't set at compile-time.
[`slow_vector_initialization`]: catch `Vec::new()` followed by `.resize(len, 0)`
Closes#10938
changelog: [`slow_vector_initialization`]: catch `Vec::new()` followed by `.resize(len, 0)`
New lint [`needless_return_with_try`]
Closes#10902
Rather than having a config option, this will just suggest removing the "return"; if `try_err` is used as well, then it'll be added again but without the `?`.
changelog: New lint [`needless_return_with_try`]
ptr_arg should ignore extern functions
Fixes: #11181
changelog: [`ptr_arg`]: ignore extern functions that are not
I am not sure whether we should ignore other Rust calling conventions like `rust-intrinsic`, `rust-call` or `rust-cold`.
`unwrap_or_else_default` -> `unwrap_or_default` and improve resulting lint
Resolves#10080 (though it doesn't implement exactly what's described there)
This PR does the following:
1. Merges `unwrap_or_else_default.rs`'s code into `or_fun_call.rs`
2. Extracts the code to handle `unwrap_or(/* default value */)` and similar, and moves it into `unwrap_or_else_default`
3. Implements the missing functionality from #9342, e.g.,, to handle `or_insert_with(Default::default)`
4. Renames `unwrap_or_else_default` to `unwrap_or_default` (since the "new" lint handles both `unwrap_or` and `unwrap_or_else`, it seemed sensible to use the shortened name)
This PR is currently two commits. The first implements 1-3, the second implements 4.
A word about 2: the `or_fun_call` lint currently produces warnings like the following:
```
error: use of `unwrap_or` followed by a call to `new`
--> $DIR/or_fun_call.rs:56:14
|
LL | with_new.unwrap_or(Vec::new());
| ^^^^^^^^^^^^^^^^^^^^^ help: try: `unwrap_or_default()`
```
To me, such warnings look like they should come from `unwrap_or_else_default`, not `or_fun_call`, especially since `or_fun_call` is [in the nursery](https://github.com/rust-lang/rust-clippy/pull/9829).
---
changelog: Move: Renamed `unwrap_or_else_default` to [`unwrap_or_default`]
[#10120](https://github.com/rust-lang/rust-clippy/pull/10120)
changelog: Enhancement: [`unwrap_or_default`]: Now handles more functions, like `or_insert_with`
[#10120](https://github.com/rust-lang/rust-clippy/pull/10120)
<!-- changelog_checked-->
check that the types are equal in `SpanlessEq::eq_expr`
Fixes#11213
changelog: [`if_same_then_else`]: don't lint for integer literals of different types
Fix async functions handling for `needless_pass_by_ref_mut` lint
Fixes https://github.com/rust-lang/rust-clippy/issues/11179.
The problem with async is that "internals" are actually inside a closure from the `ExprUseVisitor` point of view, meaning we need to actually run the check on the closures' body as well.
changelog: none
r? `@llogiq`
Make `comparison_to_empty` work on `if let`/`let` chains
This adds `LetChain` to `clippy_utils::higher`, other lints may benefit from such a change as well :D
changelog: Enhancement: [`comparison_to_empty`]: Now lints on `if let`
[`unused_async`]: don't lint if paths reference async fn without immediate call
Fixes#9695Fixes#9359
Clippy shouldn't lint unused `async` if there are paths referencing them if that path isn't the receiver of a function call, because that means that the function might be passed to some other function:
```rs
async fn f() {} // No await statements, so unused at this point
fn requires_fn_future<F: Future<Output = ()>>(_: fn() -> F) {}
requires_fn_future(f); // `f`'s asyncness is actually not unused.
```
(This isn't limited to just passing the function as a parameter to another function, it could also first be stored in a variable and later passed to another function as an argument)
This requires delaying the linting until post-crate and collecting path references to local async functions along the way.
changelog: [`unused_async`]: don't lint if paths reference async fn that require asyncness
fix dogfood lints in `redundant_local`
keep `redundant_local` from running in proc macros
rewrite `redundant_local` as late pass
make redundant_local's `find_binding` more readable
pluralize `redundant_locals` name
add test for `redundant_locals` in macros
test `redundant_locals` in proc macros
use more destructuring in `redundant_locals`
fix: format redundant_locals.rs
ignore needless_pass_by_mut_ref in redundant_locals test
Allow `Self::cmp(self, other)` as a correct impl
Fixes#11178
Also no longer checks if the method name is *just* cmp, but the path. That was an oversight on my part ^^
r? `@xFrednet`
(and `@blyxyas` too!)
changelog: [`incorrect_partial_ord_impl_on_ord_type`]: Now allows non-method calls to `cmp` like `Self::cmp(self, other)`
fix: false positive for `option_env!` in `ifs_same_cond`
Clippy had a false positive for with `ifs_same_cond` when two if-let expressions have an `option_env!` macro. The fix is similar to the `env!` macro fix.
The following example had a clippy error:
```rust
if let Some(env1) = option_env!("ENV1") {
// ...
} else if let Some(env2) = option_env!("ENV2") {
// ...
}
```
See https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=01b85c61b56ddd900117fb247af04824
changelog: [`ifs_same_cond`]: fix false positive when using `option_env!` in if-let expressions.
[`unnecessary_literal_unwrap`]: Fix ICE on None.unwrap_or_default()
Fixes#11099Fixes#11064
I'm running into #11099 (cc `@y21)` on my Rust codebase. Clippy ICEs on this code when evaluating the `unnecessary_literal_unwrap` lint:
```rust
fn main() {
let val1: u8 = None.unwrap_or_default();
}
```
This fixes that ICE and adds an message specifically for that case:
```
error: used `unwrap_or_default()` on `None` value
--> $DIR/unnecessary_literal_unwrap.rs:26:5
|
LL | None::<String>.unwrap_or_default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the `None` and `unwrap_or_default()`: `String::default()`
```
This PR also fixes the same ICE with `None.unwrap_or_else` (by giving the generic error message for the lint in that case).
changelog: Fix ICE in `unnecessary_literal_unwrap` on `None.unwrap_or_default()`
Clippy had a false positive for with `ifs_same_cond` when two
if-let expressions have an `option_env!` macro. The fix is similar to the
`env!` macro fix.
The following example had a clippy error:
```rust
if let Some(env1) = option_env!("ENV1") {
// ...
} else if let Some(env2) = option_env!("ENV2") {
// ...
}
```
See https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=01b85c61b56ddd900117fb247af04824
changelog: Fix [`ifs_same_cond`] false positive when using `option_env!` in if-let expressions.
[`manual_filter_map`]: lint on `matches` and pattern matching
Fixes#8010
Previously this lint only worked specifically for a very limited set of methods on the filter call (`.filter(|opt| opt.is_some())` and `.filter(|res| res.is_ok())`). This PR extends it to also recognize `matches!` in the `filter` and pattern matching with `if let` or `match` in the `map`.
Example:
```rs
enum Enum {
A(i32),
B,
}
let _ = [Enum::A(123), Enum::B].into_iter()
.filter(|x| matches!(x, Enum::A(_)))
.map(|x| if let Enum::A(s) = x { s } else { unreachable!() });
```
Now suggests:
```diff
- .filter(|x| matches!(x, Enum::A(_))).map(if let Enum::A(s) = x { s } else { unreachable!() })
+ .filter_map(|x| match x { Enum::A(s) => Some(s), _ => None })
```
Adding this required a somewhat large change in code because it originally seemed to be specifically written with only method calls in the filter in mind, and `matches!` has different behavior in the map, so this new setup should make it possible to support more "generic" cases that need different handling for the filter and map calls.
changelog: [`manual_filter_map`]: lint on `matches` and pattern matching (and some internal refactoring)
Fix `unwrap_or_else_default` false positive
This PR fixes a false positive in the handling of `unwrap_or_else` with a default value when the value is needed for type inference.
An easy example to exhibit the false positive is the following:
```rust
let option = None;
option.unwrap_or_else(Vec::new).push(1);
```
The following code would not compile, because the fact that the value is a `Vec` has been lost:
```rust
let option = None;
option.unwrap_or_default().push(1);
```
The fix is to:
- implement a heuristic to tell whether an expression's type can be determined purely from its subexpressions, and the arguments and locals they use;
- apply the heuristic to `unwrap_or_else`'s receiver.
The heuristic returns false when applied to `option` in the above example, but it returns true when applied to `option` in either of the following examples:
```rust
let option: Option<Vec<u64>> = None;
option.unwrap_or_else(Vec::new).push(1);
```
```rust
let option = None::<Vec<u64>>;
option.unwrap_or_else(Vec::new).push(1);
```
(Aside: https://github.com/rust-lang/rust-clippy/pull/10120 unfairly contained multiple changes in one PR. I am trying to break that PR up into smaller pieces.)
---
changelog: FP: [`unwrap_or_else_default`]: No longer lints if the default value is needed for type inference
