`Conf` macro improvements
changelog: Allow `default_trait_access` in macros
Mainly this is a change to use serde as in [Manually implementing Deserialize for a struct](https://serde.rs/deserialize-struct.html), which opens the door for a cleaner implementation overall.
* Allow `default_trait_access` in macros (tangential, but used in this PR)
* Deserialize into `TryConf { conf, errors }` instead of using a global `ERRORS` variable.
* Improve the `define_Conf!` macro
* Remove the redundant string literal `(name, "name", ..)`
* Support deprecated configs with `#[conf_deprecated(message)]`. Message shows in error.
* Make the default value optional. Use `Default::default()` if omitted.
* Invalid config value error now shows the key (see test output)
* Cleaner `impl Default for Conf` (no `toml::from_str("")`)
while_immutable_cond: check condition for mutation
This fixes#6689 by also checking the bindings mutated in the condition, whereas it was previously only checked in the loop body.
---
changelog: Fix FP in [`while_immutable_cond`] where mutation in the loop variable wasn't picked up.
`implicit_return` improvements
fixes: #6940
changelog: Fix `implicit_return` suggestion for async functions
changelog: Improve `implicit_return` suggestions when returning the result of a macro
changelog: Check for `break` expressions inside a loop which are then implicitly returned
changelog: Allow all diverging functions in `implicit_return`, not just panic functions
Remove leftover plugin conf_file code
changelog: none
Removes dead code that used to support the following syntax:
```rust
#![plugin(clippy(conf_file="path/to/clippy's/configuration"))]
```
RLS (and others?) will need to remove the `&[]` from `clippy_lints::read_conf(&[], sess)`.
r? `@flip1995`
fix ice when checking rustc libstd
```
thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', src/tools/clippy/clippy_lints/src/matches.rs:1595:53
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```
I don't have a minimised testcase because I don't have time to reduce libstd down to a few lines right now.
---
changelog: fix index out of bounds access when checking rustc libstd
thread 'rustc' panicked at 'index out of bounds: the len is 0 but the index is 0', src/tools/clippy/clippy_lints/src/matches.rs:1595:53
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
I don't have a minimised testcase because I don't have time to reduce libstd down to a few lines right now.
Fix FN in `iter_cloned_collect` with a large array
fixes#6808
changelog: Fix FN in `iter_cloned_collect` with a large array
I spotted that [is_iterable_array](a362a4d1d0/clippy_lints/src/loops/explicit_iter_loop.rs (L67-L75)) function that `explicit_iter_loop` lint is using only works for array sizes <= 32.
There is this comment:
> IntoIterator is currently only implemented for array sizes <= 32 in rustc
I'm a bit confused, because I read that [IntoIterator for arrays](https://doc.rust-lang.org/src/core/array/mod.rs.html#194-201) with const generic `N` is stable since = "1.0.0". Although Const Generics MVP were stabilized in Rust 1.51.
Should I set MSRV for the current change? I will try to test with older compilers soon.
manual_unwrap_or: fix invalid code suggestion, due to macro expansion
fixes#6965
changelog: fix invalid code suggestion in `manual_unwrap_or` lint, due to macro expansion
Refactor MSRV aliases
changelog: Remove MSRV from `needless_question_mark` and change MSRV for `missing_const_for_fn` from 1.37.0 to 1.46.0.
First [mentioned on Zulip](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Better.20MSRV.20testing.20idea/near/236215074).
* Moves MSRV constants into `clippy_utils::msrvs`. Now they are named to represent a stabilized feature flag or library item that is required for a lint's suggestion.
* `needless_question_mark` no longer has MSRV. Not needed since it does not suggest adding `?`.
* `missing_const_for_fn` MSRV was changed from 1.37.0 to 1.46.0. This seems to be a past mistake.
extend `single_element_loop` to match `.iter()`
This extends `single_element_loop` to also match `[..].iter()` in the loop argument. Related to #7125, but not completely fixing it due to the lint only firing if the array expression contains a local variable.
---
changelog: none
`single_component_path_imports`: ignore `pub(crate) use some_macro;`
Fixes#7106
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Ignore exporting a macro within a crate using `pub(crate) use some_macro;` for [`single_component_path_imports`]
Unused io amount detects `.read().ok()?`
fixes#7096
changelog: unused_io_amount now detect expertion like `.read().ok()?`, `.read().or_else(|err| ...)?` and similar expressions.
Better suggestions when returning macro calls.
Suggest changeing all the break expressions in a loop, not just the final statement.
Don't lint divergent functions.
Don't suggest returning the result of any divergent fuction.
Switch transmute_ptr_to_ptr to "pedantic" class.
Per discussion in https://github.com/rust-lang/rust-clippy/issues/6372, this lint has significant false positives.
changelog: transmute_ptr_to_ptr defaults to "allow".
Add lint to check for boolean comparison in assert macro calls
This PR adds a lint to check if an assert macro is using a boolean as "comparison value". For example:
```rust
assert_eq!("a".is_empty(), false);
```
Could be rewritten as:
```rust
assert!(!"a".is_empty());
```
PS: The dev guidelines are amazing. Thanks a lot for writing them!
changelog: Add `bool_assert_comparison` lint
