Fixes to `manual_let_else`'s divergence check
A few changes to the divergence check in `manual_let_else` and moves it the implementation to `clippy_utils` since it's generally useful:
* Handle internal `break` and `continue` expressions.
e.g. The first loop is divergent, but the second is not.
```rust
{
loop {
break 'outer;
};
}
{
loop {
break;
};
}
```
* Match rust's definition of divergence which is defined via the type system.
e.g. The following is not considered divergent by rustc as the inner block has a result type of `()`:
```rust
{
'a: {
panic!();
break 'a;
};
}
```
* Handle when adding a single semicolon would make the expression divergent.
e.g. The following would be a divergent if a semicolon were added after the `if` expression:
```rust
{ if panic!() { 0 } else { 1 } }
```
changelog: None
Lint `needless_borrow` and `explicit_auto_deref` on most union field accesses
Changes both lints to follow rustc's rules around auto-deref through `ManuallyDrop` union fields rather than just bailing on union fields.
changelog: [`needless_borrow`] & [`explicit_auto_deref`]: Lint on most union field accesses
Disable `vec_box` when using different allocators
Fixes#7114
This PR disables the `vec_box` lint when the `Box` and `Vec` use different allocators (but not when they use the same - custom - allocator).
For example - `Vec<Box<i32, DummyAllocator>>` will disable the lint, and `Vec<Box<i32, DummyAllocator>, DummyAllocator>` will not disable the lint.
In addition, the applicability of this lint has been changed to `Unspecified` due to the automatic fixes potentially breaking code such as the following:
```rs
fn foo() -> Vec<Box<i32>> { // -> Vec<i32>
vec![Box::new(1)]
}
```
It should be noted that the `if_chain->let-chains` fix has also been applied to this lint, so the diff does contain many changes.
changelog: disable `vec_box` lint when using nonstandard allocators
[`mod_module_files`] Don't emit lint for mod.rs in tests
fixes: #11775
current state: indiscriminately emits the lint for mod files in tests.
The following
```
tests/
common/
mod.rs
test.rs
```
is a common pattern for code shared across the tests and is suggested in the rust book. The change adds an additional check to verify that the mod file is not in tests.
changelog: Fix [`mod_module_files`]: false positive for mod files in tests folder
fixes: #11775
current state: indiscriminately emits the lint for mod files in tests.
The following
tests/
common/
mod.rs
test.rs
is a common pattern for code shared across the tests and is suggested in
the rust book. The change adds an additional check to verify that the
mod file is not in tests.
changelog: Fix [`mod_module_files`]: false positive for mod files in
tests folder
Fix `dbg_macro` semi span calculation
`span_including_semi` was using a `BytePos` to index into a file's source which happened to work because the root file of the test started at `BytePos` 0, it didn't work for other files
changelog: none
new lint: `unnecessary_fallible_conversions`
Closes#11577
A new lint that looks for calls such as `i64::try_from(1i32)` and suggests `i64::from(1i32)`. See lint description (and linked issue) for more details for why.
There's a tiny bit of overlap with the `useless_conversion` lint, in that the other one warns `T::try_from(T)` (i.e., fallibly converting to the same type), so this lint ignores cases like `i32::try_from(1i32)` to avoid emitting two warnings for the same expression.
Also, funnily enough, with this one exception, this lint would warn on exactly every case in the `useless_conversion_try` ui test that `useless_conversion` didn't cover (but never two warnings at the same time), which is neat. I did add an `#![allow]` though since we don't want interleaved warnings from multiple lints in the same uitest.
changelog: new lint: `unnecessary_fallible_conversions`
fix enum_variant_names depending lint depending on order
changelog: [`enum_variant_names`]: fix single word variants preventing lint of later variant pre/postfixed with the enum name
fixes#11494
Single word variants prevented checking the `check_enum_start` and `check_enum_end` for being run on later variants
Use multiple pushes in `vec_init_then_push` example
Makes the perf argument clearer, since a single push doesn't have unnecessary allocations compared to `vec![x]`
changelog: none
Remove internal feature from clippy_utils
It's only used to gate a few `const`s, removing the feature gate means it doesn't have to be recompiled when moving between a normal and `-F internal` build/test/etc
changelog: none
ignore lower-camel-case words in `doc_markdown`
This fixes#11568 by ignoring camelCase words starting with a lower case letter.
r? `@blyxyas`
---
changelog: none
move `read_zero_byte_vec` to nursery
I think the concerns in #9274 are valid, and we should move this to nursery while we're reworking this.
changelog: [`read_zero_byte_vec`] moved to nursery
Expand docs on clippy::todo
https://doc.rust-lang.org/nightly/core/macro.todo.html describes that `todo!()` is intended for explicitly unfinished code. Explain this, and mention `unimplemented!()` as an alternative.
Whilst we're here, improve the punctuation on the other lints.
changelog: [`todo`]: expand docs
Fix missing parenthesis in suboptimal floating point help
This fixes#11559 by adding a branch in the `Neg` implementation for `Sugg` that adds parentheses to keep precedence in order, then using that in the suggestion. I also removed some needless `.to_string()`s while I was at it.
---
changelog: none
[`iter_without_into_iter`]: fix papercuts in suggestion and restrict linting to exported types
See #11692 for more context.
tldr: the lint `iter_without_into_iter` has suggestions that don't compile, which imo isn't that problematic because it does have the appropriate `Applicability` that tells external tools that it shouldn't be auto-applied.
However there were some obvious "errors" in the suggestion that really should've been included in my initial PR adding the lint, which is fixed by this PR:
- `IntoIterator::into_iter` needs a `self` argument.
- `IntoIterator::Iter` associated type doesn't exist. This should've just been `Item`.
This still doesn't make it machine applicable, and the remaining things are imho quite non-trivial to implement, as I've explained in https://github.com/rust-lang/rust-clippy/issues/11692#issuecomment-1773886111.
I personally think it's fine to leave it there and let the user change the remaining errors when copy-pasting the suggestion (e.g. errors caused by lifetimes that were permitted in fn return-position but are not in associated types).
This is how many of our other lint suggestions already work.
Also, we now restrict linting to only exported types. This required moving basically all of the tests around since they were previously in the `main` function. Same for `into_iter_without_iter`. The git diff is a bit useless here...
changelog: [`iter_without_into_iter`]: fix papercuts in suggestion and restrict linting to exported types
(cc `@lopopolo,` figured I should mention you since you created the issue)
https://doc.rust-lang.org/nightly/core/macro.todo.html
describes that `todo!()` is intended for explicitly unfinished
code. Explain this, and mention `unimplemented!()` as an alternative.
Whilst we're here, improve the punctuation on the other lints.
