[`implied_bounds_in_impls`]: don't ICE on default generic parameter and move to nursery
Fixes#11422
This fixes two ICEs ([1](https://github.com/rust-lang/rust-clippy/issues/11422#issue-1872351763), [2](https://play.rust-lang.org/?version=stable&mode=debug&edition=2021&gist=2901e6febb479d3bd2a74f8a5b8a9305)), and moves it to nursery for now, because this lint needs some improvements in its suggestion (see #11435, for one such example).
changelog: Moved [`implied_bounds_in_impls`] to nursery (Now allow-by-default)
[#11437](https://github.com/rust-lang/rust-clippy/pull/11437)
changelog: [`implied_bounds_in_impls`]: don't ICE on default generic parameter in supertrait clause
r? `@xFrednet` (since you reviewed my PR that added this lint, I figured it might make sense to have you review this as well since you have seen this code before. If you don't want to review this, sorry! Feel free to reroll then)
--------
As for the ICE, it's pretty complicated and very confusing imo, so I'm going to try to explain the idea here (partly for myself, too, because I've confused myself several times writing- and fixing this):
<details>
<summary>Expand</summary>
The general idea behind the lint is that, if we have this function:
```rs
fn f() -> impl PartialEq<i32> + PartialOrd<i32> { 0 }
```
We want to lint the `PartialEq` bound because it's unnecessary. That exact bound is already specified in `PartialOrd<i32>`'s supertrait clause:
```rs
trait PartialOrd<Rhs>: PartialEq<Rhs> {}
// PartialOrd<i32>: PartialEq<i32>
```
The way it does this is in two steps:
- Go through all of the bounds in the `impl Trait` return type and collect each of the trait's supertrait bounds into a vec. We also store the generic arguments for later.
- `PartialEq` has no supertraits, nothing to add.
- `PartialOrd` is defined as `trait PartialOrd: PartialEq`, so add `PartialEq` to the list, as well as the generic argument(s) `<i32>`
Once we are done, we have these entries in the vec: `[(PartialEq, [i32])]`
- Go through all the bounds again, and looking for those bounds that have their trait `DefId` in the implied bounds vec.
- `PartialEq` is in that vec. However, that is not enough, because the trait is generic. If the user wrote `impl PartialEq<String> + PartialOrd<i32>`, then `PartialOrd` clearly doesn't imply `PartialEq`. Which means, we also need to check that the generic parameters match. This is why we also collected the generic arguments in `PartialOrd<i32>`. This process of checking generic arguments is pretty complicated and is also where the two ICEs happened.
The way it checks that the generic arguments match is by comparing the generic parameters in the super trait clause:
```rs
trait PartialOrd<Rhs>: PartialEq<Rhs> {}
// ^^^^^^^^^^^^^^
```
...this needs to match...
```rs
fn f() -> impl PartialEq<i32> + ...
// ^^^^^^^^^^^^^^
```
In the compiler, the `Rhs` generic parameter is its own type and we cannot just compare it to `i32`. We need to "substitute" it.
Internally, `Rhs` is represented as `Rhs#1` (the number next to # represents the type parameter index. They start at 0, but 0 is "reserved" for the implicit `Self` generic parameter).
How do we go from `Rhs#1` to `i32`? Well, we know that all the generic parameters had to be substituted in the `impl ... + PartialOrd<i32>` type. So we subtract 1 from the type parameter index, giving us 0 (`Self` is not specified in that list of arguments). We use that as the index into the generic argument list `<i32>`. That's `i32`. Now we know that the supertrait clause looks like `: PartialEq<i32>`.
Then, we can compare that to what the user actually wrote on the bound that we think is being implied: `impl PartialEq<i32> + ...`.
Now to the actual bug: this whole logic doesn't take into account *default* generic parameters. Actually, `PartialOrd` is defined like this:
```rs
trait PartialOrd<Rhs = Self>: PartialEq<Rhs> {}
```
If we now have a function like this:
```rs
fn f() -> impl PartialOrd + PartialEq {}
```
that logic breaks apart... We look at the supertrait predicate `: PartialEq<Rhs>` (`Rhs` is `Rhs#1`), then take the first argument in the generic argument list `PartialEq<..>` to resolve the `Rhs`, but at this point we crash because there *is no* generic argument.
The index 0 is out of bounds. If this happens (and we even get to linting here, which could only happen if it passes typeck), it must mean that that generic parameter has a default type that is not required to be specified.
This PR changes the logic such that if we have a type parameter index that is out of bounds, it looks at the definition of the trait and check that there exists a default type that we can use instead.
So, we see `<Rhs = Self>`, and use `Self` for substitution, and end up with this predicate: `: PartialEq<Self>`. No crash this time.
</details>
Also stabilizes saturating_int_assign_impl, gh-92354.
And also make pub fns const where the underlying saturating_*
fns became const in the meantime since the Saturating type was
created.
Bump ui_test
This makes `ui_test` parse `--bless` and allows a follow up change to use `Mode::Error` (instead of `Mode::Yolo`) with `RustfixMode::Everything`
changelog: none
Fix span when linting `explicit_auto_deref` immediately after `needless_borrow`
fixes#11366
changelog: `explicit_auto_deref`: Fix span when linting immediately after `needless_borrow`
Add config flag for reborrows in explicit_iter_loop
This PR adds a config flag for enforcing explicit into iter lint for reborrowed values. The config flag, `enforce_iter_loop_reborrow`, can be added to clippy.toml files to enable the linting behaviour. By default the reborrow lint is disabled.
fixes: #11074
changelog: [`explicit_iter_loop`]: add config flag `enforce_iter_loop_reborrow` to disable reborrow linting by default
new lint: `iter_out_of_bounds`
Closes#11345
The original idea in the linked issue seemed to be just about arrays afaict, but I extended this to catch some other iterator sources such as `iter::once` or `iter::empty`.
I'm not entirely sure if this name makes a lot of sense now that it's not just about arrays anymore (specifically, not sure if you can call `.take(1)` on an `iter::Empty` to be "out of bounds"?).
changelog: [`iter_out_of_bounds`]: new lint
[`unnecessary_unwrap`]: lint on `.as_ref().unwrap()`
Closes#11371
This turned out to be a little more code than I originally thought, because the lint also makes sure to not lint if the user tries to mutate the option:
```rs
if option.is_some() {
option = None;
option.unwrap(); // don't lint here
}
```
... which means that even if we taught this lint to recognize `.as_mut()`, it would *still* not lint because that would count as a mutation. So we need to allow `.as_mut()` calls but reject other kinds of mutations.
Unfortunately it doesn't look like this is possible with `is_potentially_mutated` (seeing what kind of mutation happened).
This replaces it with a custom little visitor that does basically what it did before, but also allows `.as_mut()`.
changelog: [`unnecessary_unwrap`]: lint on `.as_ref().unwrap()`
skip float_cmp check if lhs is a custom type
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`float_cmp`]: allow float eq comparison when lhs is a custom type that implements PartialEq<f32/f64>
If the lhs of a comparison is not float, it means there is a user implemented PartialEq, and the caller is invoking that custom version of `==`, instead of the default floating point equal comparison.
People may wrap f32 with a struct (say `MyF32`) and implement its PartialEq that will do the `is_close()` check, so that `MyF32` can be compared with either f32 or `MyF32`.
[`if_then_some_else_none`]: look into local initializers for early returns
Fixes#11394
As the PR title says, problem was that it only looked for early returns in semi statements. Local variables don't count as such, so it didn't count `let _v = x?;` (or even just `let _ = return;`) as a possible early return and didn't realize that it can't lint then.
Imo the `stmts_contains_early_return` function that was used before is redundant. `contains_return` could already do that if we just made the parameter a bit more generic, just like `for_each_expr`, which can already accept `&[Stmt]`
changelog: [`if_then_some_else_none`]: look into local initializers for early returns
This commit adds a config flag for enforcing explicit into iter lint
for reborrowed values. The config flag, enforce_iter_loop_reborrow, can be
added to clippy.toml files to enable the linting behaviour. By default
the lint is not enabled.
fix the uitest `enum_clike_unportable_variant`
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: none
fix "derivable_impls: attributes are ignored"
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: [`derivable_impls`]: allow the lint when the trait-impl methods has any attribute.
Added new lint: `reserve_after_initialization`
Closes https://github.com/rust-lang/rust-clippy/issues/11330.
A new lint that informs the user about a more concise way to create a vector with a known capacity.
Example:
```rust
let mut v: Vec<usize> = vec![];
v.reserve(10);
```
Produces the following help:
```rust
|
2 | / let mut v: Vec<usize> = vec![];
3 | | v.reserve(10);
| |__________________^ help: consider using `Vec::with_capacity(space_hint)`: `let v: Vec<usize> = Vec::with_capacity(10);`
|
```
And can be rewritten as:
```rust
let v: Vec<usize> = Vec::with_capacity(10);
```
changelog: new lint [`reserve_after_initialization`]
Fix tuple_array_conversions lint on nightly
```
changelog: ICE: [`tuple_array_conversions`]: Don't expect array length to always be usize
```
tl;dr: changed [`Const::eval_target_usize`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/ty/consts.rs#L359) to [`Consts::try_eval_target_usize`](https://github.com/rust-lang/rust/blob/master/compiler/rustc_middle/src/ty/consts.rs#L327) to get rid of ICE.
I have encountered a problem with clippy: it caught ICE when working with a codebase that uses a lot of nightly features.
Here's a (stripped) ICE info:
```
error: internal compiler error: /rustc/5c6a7e71cd66705c31c9af94077901a220f0870c/compiler/rustc_middle/src/ty/consts.rs:361:32: expected usize, got Const { ty: usize, kind: N/#1 }
thread 'rustc' panicked at /rustc/5c6a7e71cd66705c31c9af94077901a220f0870c/compiler/rustc_errors/src/lib.rs:1635:9:
Box<dyn Any>
stack backtrace:
...
16: 0x110b9c590 - rustc_middle[449edf845976488d]::util:🐛:bug_fmt
17: 0x102f76ae0 - clippy_lints[71754038dd04c2d2]::tuple_array_conversions::all_bindings_are_for_conv
...
```
I don't really know what's going on low-level-wise, but seems like this lin assumed that the length of the array can always be treated as `usize`, and *I assume* this doesn't play well with `feat(generic_const_exprs)`.
I wasn't able to build a minimal reproducible example, but locally this fix does resolve the issue.
key idea:
for `f` in `.map(f)` and `.for_each(f)`:
1. `f` must be a closure with one parameter
2. don't lint if mutable paramter in clsure `f`: `|mut x| ...`
3. don't lint if parameter is moved
[new_without_default]: include `where` clause in suggestions, make applicable
changelog: [`new_without_default`]: include `where` clause in suggestions
Correctly handle async blocks for NEEDLESS_PASS_BY_REF_MUT
Fixes https://github.com/rust-lang/rust-clippy/issues/11299.
The problem was that the `async block`s are popping a closure which we didn't go into, making it miss the mutable access to the variables.
cc `@Centri3`
changelog: none
[`useless_conversion`]: only lint on paths to fn items and fix FP in macro
Fixes#11065 (which is actually two issues: an ICE and a false positive)
It now makes sure that the function call path points to a function-like item (and not e.g. a `const` like in the linked issue), so that calling `TyCtxt::fn_sig` later in the lint does not ICE (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616836099).
It *also* makes sure that the expression is not part of a macro call (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616919639). ~~I'm not sure if there's a better way to check this other than to walk the parent expr chain and see if any of them are expansions.~~ (edit: it doesn't do this anymore)
changelog: [`useless_conversion`]: fix ICE when call receiver is a non-fn item
changelog: [`useless_conversion`]: don't lint if argument is a macro argument (fixes a FP)
r? `@llogiq` (reviewed #10814, which introduced these issues)
Correctly handle async blocks for NEEDLESS_PASS_BY_REF_MUT
Fixes https://github.com/rust-lang/rust-clippy/issues/11299.
The problem was that the `async block`s are popping a closure which we didn't go into, making it miss the mutable access to the variables.
cc `@Centri3`
changelog: none
[`useless_conversion`]: only lint on paths to fn items and fix FP in macro
Fixes#11065 (which is actually two issues: an ICE and a false positive)
It now makes sure that the function call path points to a function-like item (and not e.g. a `const` like in the linked issue), so that calling `TyCtxt::fn_sig` later in the lint does not ICE (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616836099).
It *also* makes sure that the expression is not part of a macro call (fixes https://github.com/rust-lang/rust-clippy/issues/11065#issuecomment-1616919639). ~~I'm not sure if there's a better way to check this other than to walk the parent expr chain and see if any of them are expansions.~~ (edit: it doesn't do this anymore)
changelog: [`useless_conversion`]: fix ICE when call receiver is a non-fn item
changelog: [`useless_conversion`]: don't lint if argument is a macro argument (fixes a FP)
r? `@llogiq` (reviewed #10814, which introduced these issues)
Use ui_test's Windows path backslash heuristic
changelog: none
Instead of unconditionally replacing `\` with `/` we now use [`Match::PathBackslash`](https://docs.rs/ui_test/latest/ui_test/enum.Match.html#variant.PathBackslash) to only replace backslashes in paths that look like windows paths
`ui-toml` and `ui-cargo` tests still use the old way because they produce verbatim paths on windows in some tests (`\\?\C:\foo\...`) which was finnicky to get the replacement order correct with
Also removes the `ui_test` -> `compiletest` alias and `VarGuard`
Fix SPEEDTEST instructions and output
* `--nocapture` hasn't been needed anymore since forever (even before `ui_test`)
* the result was dividing by 1000 instead of the number of test runs, giving bogus (but still useful for the purpose) timing results.
changelog: fix SPEEDTEST instructions and output
redundant_locals: fix FPs on mutated shadows
Fixes#11290.
When a mutable binding is shadowed by
a mutable binding of the same name in a different scope, mutations in that scope have different meaning.
This PR fixes spurious `redundant_locals` emissions on such locals.
cc `@Centri3,` `@flip1995`
changelog: [`redundant_locals`]: fix false positives on mutated shadows
Rustup
r? `@ghost`
cc `@max-niederman` With the latest sync, I'm getting a lot of FP in the `redundant_locals` lint you recently added. Any ideas where this could come from?
changelog: none
When a mutable binding is shadowed by
a mutable binding of the same name in a different scope,
mutations in that scope have different meaning.
This commit fixes spurious `redundant_locals` emissions
on such locals.
[`redundant_guards`]: don't lint on float literals
Fixes#11304
changelog: [`redundant_guards`]: don't lint on float literals
r? `@Centri3` i figured you are probably a good reviewer for this since you implemented the lint ^^
redundant_type_annotations: only pass certain def kinds to type_of
Fixes#11190Fixesrust-lang/rust#113516
Also adds an `is_lint_allowed` check to skip the lint when it's not needed
changelog: none
Add `internal_features` lint
Implements https://github.com/rust-lang/compiler-team/issues/596
Also requires some more test blessing for codegen tests etc
`@jyn514` had the idea of just `allow`ing the lint by default in the test suite. I'm not sure whether this is a good idea, but it's definitely one worth considering. Additional input encouraged.
Fix `suspicious_xor_used_as_pow.rs` performance
The original `suspicious_xor_used_as_pow` lint had poor performance, so I fixed that + a little refactor so that module is readable.
**107 millis. -> 106 millis.** Using `SPEEDTEST` on Rust's VMs
fix#11060
changelog: [`suspicious_xor_used_as_pow`]: Improve performance by 0.934%
It lints against features that are inteded to be internal to the
compiler and standard library. Implements MCP #596.
We allow `internal_features` in the standard library and compiler as those
use many features and this _is_ the standard library from the "internal to the compiler and
standard library" after all.
Marking some features as internal wasn't exactly the most scientific approach, I just marked some
mostly obvious features. While there is a categorization in the macro,
it's not very well upheld (should probably be fixed in another PR).
We always pass `-Ainternal_features` in the testsuite
About 400 UI tests and several other tests use internal features.
Instead of throwing the attribute on each one, just always allow them.
There's nothing wrong with testing internal features^^
New lint `ignored_unit_patterns`
This idea comes from #11238. I've put the lint in `pedantic` as it might trigger numerous positives (three in Clippy itself).
changelog: [`ignored_unit_patterns`]: new lint
Suppress `question_mark` warning if `question_mark_used` is not allowed
Closes#11283
changelog: [`question_mark`]: Don't lint if `question_mark_used` is not allowed
Rename and allow `cast_ref_to_mut` lint
This PR is a small subset of https://github.com/rust-lang/rust/pull/112431, that is the renaming of the lint (`cast_ref_to_mut` -> `invalid_reference_casting`).
BUT also temporarily change the default level of the lint from deny-by-default to allow-by-default until https://github.com/rust-lang/rust/pull/112431 is merged.
r? `@Nilstrieb`
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.
