[`useless_conversion`]: don't lint if type parameter has unsatisfiable bounds for `.into_iter()` receiver
Fixes#11300.
Before this PR, clippy assumed that if it sees a `f(x.into_iter())` call and the type at that argument position is generic over any `IntoIterator`, then the `.into_iter()` call must be useless because `x` already implements `IntoIterator`, *however* this assumption is not right if the generic parameter has more than just the `IntoIterator` bound (because other traits can be implemented for the IntoIterator target type but not the IntoIterator implementor, as can be seen in the linked issue: `<[i32; 3] as IntoIterator>::IntoIter` satisfies `ExactSizeIterator`, but `[i32; 3]` does not).
So, this PR makes it check that the type parameter only has a single `IntoIterator` bound. It *might* be possible to check if the type of `x` in `f(x.into_iter())` satisfies all the bounds on the generic type parameter as defined on the function (which would allow removing the `.into_iter()` call even with multiple bounds), however I'm not sure how to do that, and the current fix should always work.
**Edit:** This PR has been changed to check if any of the bounds don't hold for the type of the `.into_iter()` receiver, so we can still lint in some cases.
changelog: [`useless_conversion`]: don't lint `.into_iter()` if type parameter has multiple bounds
new lint: `path_ends_with_ext`
Closes#11479
Not sure if it needs more test cases. I couldn't come up with any other ones, but it is a pretty simple lint logic wise with not too many checks
changelog: new lint: [`path_ends_with_ext`]
fix filter_map_bool_then with a bool reference
changelog: [`filter_map_bool_then`]: Fix the incorrect autofix when the `bool` in question is a reference.
fix#11503
[`extra_unused_type_parameters`]: Fix edge case FP for parameters in where bounds
Generic parameters can end up being used on the left side of where-bounds if they are not directly bound but instead appear nested in some concrete generic type. Therefore, we should walk the left side of where bounds, but only if the bounded type is *not* a generic param, in which case we still need to ignore the bound.
Fixes#11302
changelog: [`extra_unused_type_parameters`]: Fix edge case false positive for parameters in where bounds
Ignore closures for some type lints
Fixes#11417
`hir_ty_to_ty` is used in a couple of the `!is_local` lints, which doesn't play nicely inside bodies
changelog: none
Truncate files when opening in metadata-collector
Fixes the issue seen here https://github.com/rust-lang/rust-clippy/pull/11483#discussion_r1324687136 and in a couple other PRs
The changelog file was opened without truncating it, so if the new version is shorter than the old one stray contents would remain at the end of the file
The other two files first removed the file so didn't have this problem, but in all cases we now use `fs::write`/`File::create` which is write + create + truncate
changelog: none
Improve invalid let expression handling
- Move all of the checks for valid let expression positions to parsing.
- Add a field to ExprKind::Let in AST/HIR to mark whether it's in a valid location.
- Suppress some later errors and MIR construction for invalid let expressions.
- Fix a (drop) scope issue that was also responsible for #104172.
Fixes#104172Fixes#104868
treat host effect params as erased in codegen
This fixes the changes brought to codegen tests when effect params are added to libcore, by not attempting to monomorphize functions that get the host param by being `const fn`.
r? `@oli-obk`
This fixes the changes brought to codegen tests when effect params are
added to libcore, by not attempting to monomorphize functions that get
the host param by being `const fn`.
[`len_without_is_empty`]: follow type alias to find inherent `is_empty` method
Fixes#11165
When we see an `impl B` and `B` is a type alias to some type `A`, then we need to follow the type alias to look for an `is_empty` method on the aliased type `A`. Before this PR, it'd get the inherent impls of `B`, which there aren't any and so it would warn that there isn't an `is_empty` method even if there was one.
Passing the type alias `DefId` to `TyCtxt::type_of` gives us the aliased `DefId` (or simply return the type itself if it wasn't a type alias) so we can just use that
changelog: [`len_without_is_empty`]: follow type alias to find inherent `is_empty` method
Ignore span's parents in `collect_ast_format_args`/`find_format_args`
Fixes#11470, covers some cases missed by #10980
Can't have a test yet because of #11126 but it works locally
changelog: none
r? `@dswij`
new unnecessary_map_on_constructor lint
changelog: [`unnecessary_map_on_constructor`]: adds lint for cases in which map is not necessary. `Some(4).map(myfunction)` => `Some(myfunction(4))`
Closes https://github.com/rust-lang/rust-clippy/issues/6472
Note that the case mentioned in the issue `Some(..).and_then(|..| Some(..))` is fixed by a chain of lint changes. This PR completes the last part of that chain.
By `bind_instead_of_map`[lint](https://rust-lang.github.io/rust-clippy/master/index.html#/bind_instead_of_map):
`Some(4).and_then(|x| Some(foo(4)))` => `Some(4).map(|x| foo)`
By `redundant_closure` [lint](https://rust-lang.github.io/rust-clippy/master/index.html#/redundant_closure):
`Some(4).map(|x| foo)` => `Some(4).map(fun)`
Finally by this PR `unnecessary_map_on_constructor`:
`Some(4).map(fun)` => `Some(fun(4))`
I'm not sure this is the desired behavior for clippy and if it should be addressed in another issue/PR. I'd be up to give it a try if that's the case.
