Handle const effects inherited from parent correctly in `type_certainty`
This fixes a (debug) ICE in `type_certainty` that happened in the [k256 crate]. (I'm sure you can also specifically construct an edge test case that will run into type_certainty false positives visible outside of debug builds from this bug)
<details>
<summary>Minimal ICE repro</summary>
```rs
use std::ops::Add;
Add::add(1_i32, 1).add(i32::MIN);
```
</details>
The subtraction here overflowed:
436675b477/clippy_utils/src/ty/type_certainty/mod.rs (L209)
... when we have something like `Add::add` where `add` fn has 0 generic params but the `host_effect_index` is `Some(2)` (inherited from the parent generics, the const trait `Add`), and we end up executing `0 - 1`.
(Even if the own generics weren't empty and we didn't overflow, this would still be wrong because it would assume that a trait method with 1 generic parameter didn't have any generics).
So, *only* exclude the "host" generic parameter if it's actually bound by the own generics
changelog: none
[k256 crate]: https://github.com/RustCrypto/elliptic-curves/tree/master/k256
Fix grammer for the Safety documentation check
The original message ("unsafe function's docs miss `# Safety` section") reads quite awkwardly. I've changed it to "unsafe function's docs are missing a `# Safety` section" to have it read better.
```
changelog: [`missing_headers`]: Tweak the grammar in the lint message
```
[`overly_complex_bool_expr`]: Fix trigger wrongly on never type
fixes#12689
---
changelog: fix [`overly_complex_bool_expr`] triggers wrongly on never type
Dedup nonminimal_bool_methods diags
Relates to #12379
Fix `nonminimal_bool` lint so that it doesn't check the same span multiple times.
`NotSimplificationVisitor` was called for each expression from `NonminimalBoolVisitor` whereas `NotSimplificationVisitor` also recursively checked all expressions.
---
changelog: [`nonminimal_bool`]: Fix duplicate diagnostics
The original message ("unsafe function's docs miss `# Safety` section")
reads quite awkwardly. I've changed it to "unsafe function's docs are missing
a `# Safety` section" to have it read better.
Signed-off-by: Paul R. Tagliamonte <paultag@gmail.com>
Modify str_to_string to be machine-applicable
Fixes https://github.com/rust-lang/rust-clippy/issues/12768
I'm not sure if there is any potential for edge cases with this - since it only ever acts on `&str` types I can't think of any, and especially since the methods do the same thing anyway.
changelog: allow `str_to_string` lint to be automatically applied
Disable `indexing_slicing` for custom Index impls
Fixes https://github.com/rust-lang/rust-clippy/issues/11525
Disables `indexing_slicing` for custom Index impls, specifically any implementations that also do not have a `get` method anywhere along the deref chain (so, for example, it still lints on Vec, which has its `get` method as part of the deref chain).
Thanks `@y21` for pointing me in the right direction with a couple of handy util functions for deref chain and inherent methods, saved a headache there!
changelog: FP: Disable `indexing_slicing` for custom Index impls
fix: let non_canonical_impls skip proc marco
Fixed#12788
Although the issue only mentions `NON_CANONICAL_CLONE_IMPL`, this fix will also affect `NON_CANONICAL_PARTIAL_ORD_IMPL` because I saw
> Because of these unforeseeable or unstable behaviors, macro expansion should often not be regarded as a part of the stable API.
on Clippy Documentation and these two lints are similar, so I think it might be good, not sure if it's right or not.
---
changelog: `NON_CANONICAL_CLONE_IMPL`, `NON_CANONICAL_PARTIAL_ORD_IMPL` will skip proc marco now
[`many_single_char_names`]: Deduplicate diagnostics
Relates to #12379
Fix `many_single_char_names` lint so that it doesn't emit diagnostics when the current level of the scope doesn't contain any single character name.
```rust
let (a, b, c, d): (i32, i32, i32, i32);
match 1 {
1 => (),
e => {},
}
```
produced the exact same MANY_SINGLE_CHAR_NAMES diagnostic at each of the Arm `e => {}` and the Block `{}`.
---
changelog: [`many_single_char_names`]: Fix duplicate diagnostics
Fix `unnecessary_to_owned` interaction with macro expansion
fixes#12821
In the case of an unnecessary `.iter().cloned()`, the lint `unnecessary_to_owned` might suggest to remove the `&` from references without checking if such references are inside a macro expansion. This can lead to unexpected behavior or even broken code if the lint suggestion is applied blindly. See issue #12821 for an example.
This PR checks if such references are inside macro expansions and skips this part of the lint suggestion in these cases.
changelog: [`unnecessary_to_owned`]: Don't suggest to remove `&` inside macro expansion
[perf] Delay the construction of early lint diag structs
Attacks some of the perf regressions from https://github.com/rust-lang/rust/pull/124417#issuecomment-2123700666.
See individual commits for details. The first three commits are not strictly necessary.
However, the 2nd one (06bc4fc67145e3a7be9b5a2cf2b5968cef36e587, *Remove `LintDiagnostic::msg`*) makes the main change way nicer to implement.
It's also pretty sweet on its own if I may say so myself.
`significant_drop_in_scrutinee`: Trigger lint only if lifetime allows early significant drop
I want to argue that the following code snippet should not trigger `significant_drop_in_scrutinee` (https://github.com/rust-lang/rust-clippy/issues/8987). The iterator holds a reference to the locked data, so it is expected that the mutex guard must be alive until the entire loop is finished.
```rust
use std::sync::Mutex;
fn main() {
let mutex_vec = Mutex::new(vec![1, 2, 3]);
for number in mutex_vec.lock().unwrap().iter() {
dbg!(number);
}
}
```
However, the lint should be triggered when we clone the vector. In this case, the iterator does not hold any reference to the locked data.
```diff
- for number in mutex_vec.lock().unwrap().iter() {
+ for number in mutex_vec.lock().unwrap().clone().iter() {
```
Unfortunately, it seems that regions on the types of local variables are mostly erased (`ReErased`) in the late lint pass. So it is hard to tell if the final expression has a lifetime relevant to the value with a significant drop.
In this PR, I try to make a best-effort guess based on the function signatures. To avoid false positives, no lint is issued if the result is uncertain. I'm not sure if this is acceptable or not, so any comments are welcome.
Fixes https://github.com/rust-lang/rust-clippy/issues/8987
changelog: [`significant_drop_in_scrutinee`]: Trigger lint only if lifetime allows early significant drop.
r? `@flip1995`
