`SpanlessEq` improvements
fixes#9775
Also includes a simplification to `consts::constant`'s interface since I was already touching the code.
At the start of `eq_expr` the check:
```rust
if !self.inner.allow_side_effects && left.span.ctxt() != right.span.ctxt() {
return false;
}
```
was removed. This was added in 49e2501 to handle `cfg` macros. This is better handled by the newly added `check_ctxt`.
changelog: [various lints]: Don't consider different `cfg!` expansions to be the same unless they are for the same config.
changelog: [various lints]: Don't consider the expansion of two different macros to be equal, even when they expand to the same token sequence.
changelog: [various lints]: Don't consider two blocks to be equal if they contain disabled code or empty macro expansions, unless those section contain the exact same token sequence.
* Don't consider expansions of different macros to be the same, even if they expand to the same tokens
* Don't consider `cfg!` expansions to be equal if they check different configs.
* Replace variables inside | patterns in the if let: let v = if let V::A(v) | V::B(v) = v { v } else ...
* Support nested patterns: let v = if let Ok(Ok(Ok(v))) = v { v } else ...
* Support tuple structs with more than one arg: let v = V::W(v, _) = v { v } else ...
* Correctly handle .. in tuple struct patterns: let v = V::X(v, ..) = v { v } else ...
Rename `integer_arithmetic`
The lack of official feedback in #10200 made me give up on pursuing the matter but after yet another use-case that is not handled by `integer_arithmetic` (#10615), I think it is worth trying again.
---
changelog: Move/Deprecation: Rename `integer_arithmetic` to `arithmetic_side_effects`
[#10674](https://github.com/rust-lang/rust-clippy/pull/10674)
<!-- changelog_checked -->
don't remove `dbg!` in arbitrary expressions
Fixes#9914
The `dbg_macro` lint replaces empty `dbg!` invocations with the empty string in its suggestion, which is not always valid code in certain contexts (e.g. `let _ = dbg!();` becomes `let _ = ;`). This PR changes it to `()`, which should always be valid where `dbg!()` is valid (`dbg!()` with no arguments evaluates to `()`).
It also special-cases "standalone" `dbg!();` expression statements, where it will suggest removing the whole statement entirely like it did before.
changelog: [`dbg_macro`]: don't remove `dbg!()` in arbitrary expressions as it sometimes results in syntax errors
Remove unnecessary `clone` from `needless_collect` example
The example for [clippy::needless_collect](https://rust-lang.github.io/rust-clippy/master/#needless_collect) is written as follows:
```rust
let len = iterator.clone().collect::<Vec<_>>().len();
// should be
let len = iterator.count();
```
With this change, the unnecessary `clone()` is removed and the the standard
### Example
```rust
// original
```
Use instead:
```rust
// improved
```
structure is followed.
Discussion: https://github.com/rust-lang/rust-clippy/discussions/10784#discussion-5198885
changelog: [`needless_collect`]: Cleaned up the example in the lint documentation.
fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
fixes: #10680
---
changelog: fix [`invalid_regex`] not recognizing new syntax introduced after regex-1.8.0
bump up `regex-syntax` dependency version to 0.7.0
Fix: Some suggestions generated by the option_if_let_else lint did not compile
This addresses a bug in Clippy where the fix suggestend by the `option_if_let_else` lint would not compile for `Result`s which have an impure expression in the `else` branch.
---
changelog: [`option_if_let_else`]: Fixed incorrect suggestion for `Result`s
[#10337](https://github.com/rust-lang/rust-clippy/pull/10337)
<!-- changelog_checked -->
Fixes#10335.
Updates `needless_collect` to lint for collecting into a method or
function argument thats taking an `IntoIterator` (for example `extend`).
Every `Iterator` trivially implements `IntoIterator` and colleting it
only causes an unnecessary allocation.
[arithmetic_side_effects] Consider referenced allowed or hard-coded types
Fix#10767
```
changelog: [`arithmetic_side_effects`]: Do not fire when dealing with allowed or hard-coded types that are referenced.
```
fix: warn on empty line outer AttrKind::DocComment
changelog: [`empty_line_after_doc_comments`]: add lint for checking empty lines after rustdoc comments.
Fixes: #10395
add lint `manual_next_back`
changelog: [`manual_next_back`]: checks for manual reverse iteration (`.rev().next()`) of a `DoubleEndedIterator`
fixes#10274
