Rework `only_used_in_recursion`
fixes#8782fixes#8629fixes#8560fixes#8556
This is a complete rewrite of the lint. This loses some capabilities of the old implementation. Namely the ability to track through tuple and slice patterns, as well as the ability to trace through assignments.
The two reported bugs are fixed with this. One was caused by using the name of the method rather than resolving to the `DefId` of the called method. The second was cause by using the existence of a cycle in the dependency graph to determine whether the parameter was used in recursion even though there were other ways to create a cycle in the graph.
Implementation wise this switches from using a visitor to walking up the tree from every use of each parameter until it has been determined the parameter is used for something other than recursion. This is likely to perform better as it avoids walking the entire function a second time, and it is unlikely to walk up the HIR tree very much. Some cases would perform worse though.
cc `@buttercrab`
changelog: Scale back `only_used_in_recursion` to fix false positives
changelog: Move `only_used_in_recursion` back to `complexity`
Enhance `needless_borrow` to consider trait implementations
The proposed enhancement causes `needless_borrow` to suggest removing `&` from `&e` when `&e` is an argument position requiring trait implementations, and `e` implements the required traits. Example:
```
error: the borrowed expression implements the required traits
--> $DIR/needless_borrow.rs:131:51
|
LL | let _ = std::process::Command::new("ls").args(&["-a", "-l"]).status().unwrap();
| ^^^^^^^^^^^^^ help: change this to: `["-a", "-l"]`
```
r? `@Jarcho`
changelog: Enhance `needless_borrow` to consider trait implementations
unwrap_used and expect_used: trigger on uses of their _err variants
changelog: [`unwrap_used`]: lint uses of `unwrap_err`
changelog: [`expect_used`]: lint uses of `expect_err`
fixes#9331
`transmute_undefined_repr` fix
changelog: Don't lint `transmute_undefined_repr` when the the first field of a `repr(C)` type is compatible with the other type
suggest map_or in case_sensitive_file_extension_comparisons
changelog: [`case_sensitive_file_extension_comparisons `]: updated suggestion in the example to use `map_or`
Currently, case_sensitive_file_extension_comparisons suggests using `map(..).unwrap_or(..)` which trips up the `map_unwrap_or` lint. This updates the suggestion to use `map_or`.
Fix [`non_ascii_literal`] in tests
changelog: Don't lint [`non_ascii_literal`] when using non-ascii comments in tests
changelog: Don't lint [`non_ascii_literal`] when `allow`ed on tests
closes: #7739closes: #8263
Currently, case_sensitive_file_extension_comparisons suggests using
`map(..).unwrap_or(..)` which trips up `map_unwrap_or`. This updates
the suggestion to use map_or.
Add new lint [`positional_named_format_parameters`]
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: Add new lint [`positional_named_format_parameters`] to warn when named parameters in format strings are used as positional arguments.
Fix if_let_mutex not checking Mutexes behind refs
Fixes#9193
We can always peel references because we are looking for a method-call, for which autoderef applies.
---
changelog: [`if_let_mutex`]: detect calls to `Mutex::lock()` if mutex is behind a ref
changelog: [`if_let_mutex`]: Add labels to the two instances of the same Mutex that will deadlock
