Downgrade rc_buffer to restriction
I think Arc\<Vec\<T\>\> and Arc\<String\> and similar are a totally reasonable data structure, as observed by others in the comments on [#6044](https://github.com/rust-lang/rust-clippy/pull/6044#event-3799579830) as well. Doing `Arc::make_mut(&mut self.vec).push(...)` or `Arc::make_mut(&mut self.string).push_str("...")` is a terrific and well performing copy-on-write pattern. Linting this with an enabled-by-default <kbd>performance</kbd> lint strikes me as an unacceptable false positive balance.
As of #6090 the documentation of this lint now contains:
> **Known problems:** This pattern can be desirable ...
which should indicate that we shouldn't be linting against correct, reasonable, well-performing patterns with an enabled-by-default lint.
Mentioning #6044, #6090.
r? `@yaahc,` who reviewed the lint.
---
changelog: Remove rc_buffer from default set of enabled lints
Fix LitKind's byte buffer to use refcounted slice
While working on adding a new lint for clippy (see https://github.com/rust-lang/rust-clippy/pull/6044) for avoiding shared ownership of "mutable buffer" types (such as using `Rc<Vec<T>>` instead of `Rc<[T]>`), I noticed a type exported from rustc_ast and used by clippy gets caught by the lint. This PR fixes the exported type.
This PR includes the actual change to clippy too, but I will open a PR directly against clippy for that part (although it will currently fail to build there).
unnecessary sort by: avoid dereferencing the suggested closure parameter
This change tries to simplify the solution for problematic cases but is less restrictive than #6006.
* We can't dereference shared references to non-Copy types, so the new suggestion does not do that. Note that this implies that the suggested closure parameter will be a reference.
* We can't take a reference to the closure parameter in the returned key, so we don't lint in those cases. This can happen either because the key borrows from the parameter (e.g. `|a| a.borrows()`), or because we suggest `|a| Reverse(a)`. If we did we would hit this error:
```
error: lifetime may not live long enough
--> /home/ebroto/src/ebroto-clippy/tests/ui/unnecessary_sort_by.fixed:19:25
|
19 | vec.sort_by_key(|b| Reverse(b));
| -- ^^^^^^^^^^ returning this value requires that `'1` must outlive `'2`
| ||
| |return type of closure is Reverse<&'2 isize>
| has type `&'1 isize`
error: aborting due to previous error
```
Note that Clippy does not currently have the (MIR-based) machinery necessary to check that what is borrowed is actually the closure parameter.
changelog: [`unnecessary_sort_by`]: avoid dereferencing the suggested closure parameter
Fixes#6001
Do not lint float fractions in `mistyped_literal_suffixes`
As suggested in https://github.com/rust-lang/rust-clippy/issues/4706#issuecomment-544797928, the fractional part is now ignored (the integer part is checked instead).
Fixes: #4706
changelog: `mistyped_literal_suffixes` no longer warns on the fractional part of a float (e.g. 713.23_64)
fix a false positive in two `interior_mutable_const` lints where a constant with enums gets linted
even if it uses a clearly unfrozen variant. Note that the code uses the MIR interpreter, which
the author of #3962 thought unlikely to be a solution. This might be over-engineering;
but, I think it's important to be able to work with the 'http' crate (#3825).
Lint for invisible Unicode characters other than ZWSP
This PR extends the existing `zero_width_space` lint to look for other invisible characters as well (in this case, `\\u{ad}` soft hyphen.
I feel like this lint is the logical place to add the check, but I also realize the lint name is not particularly flexible, but I also understand that it shouldn't be renamed for compatibility reasons.
Open questions:
- What other characters should trigger the lint?
- What should be done with the lint name?
- How to indicate the change in functionality?
Motivation behind this PR: https://github.com/rust-lang/rust/issues/77417 - I managed to shoot myself in the foot by an invisible character pasted into my test case.
changelog: rename [`zero_width_space`] to [`invisible_characters`] and add SHY and WJ to the list.
Don't emit a lint for the suggestion leading to errors in `needless_range_loop`
Fix#5945
changelog: Don't emit a lint for the suggestion leading to errors in `needless_range_loop`
