New lint: default_numeric_fallback
fixes#6064
r? `@flip1995`
As we discussed in [here](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Issue.20.236064/near/224647188) and [here](https://rust-lang.zulipchat.com/#narrow/stream/257328-clippy/topic/Issue.20clippy.236064/near/224746333), I start implementing this lint from the strictest version.
In this PR, I'll allow the below two cases to pass the lint to reduce FPs.
1. Appearances of unsuffixed numeric literals in `Local` if `Local` has a type annotation, for example:
```rust
// Good.
let x: i32 = 1;
// Also good.
let x: (i32, i32) = if cond {
(1, 2)
} else {
(2, 3)
};
```
2. Appearances of unsuffixed numeric literals in args of `Call` or `MethodCall` if corresponding arguments of their signature have concrete types, for example:
```rust
fn foo_mono(x: i32) -> i32 {
x
}
fn foo_poly<T>(t: T) -> t {
t
}
// Good.
let x = foo_mono(13);
// Still bad.
let x: i32 = foo_poly(13);
```
changelog: Added restriction lint: `default_numeric_fallback`
Do not lint when the closure is called using an iterator
Fix FP when the closure is used in an iterator for `blocks_in_if_conditions` lint
FIxes: #1141
changelog: none
Rework use_self impl based on ty::Ty comparison #3410 | Take 2
This builds on top of #5531
I already reviewed and approved the commits by `@montrivo.` So only the review of my commits should be necessary.
I would also appreciate your review `@montrivo,` since you are familiar with the challenges here.
Fixes#3410 and Fixes#4143 (same problem)
Fixes#2843Fixes#3859Fixes#4734 and fixes#6221Fixes#4305Fixes#5078 (even at expression level now 🎉)
Fixes#3881 and Fixes#4887 (same problem)
Fixes#3909
Not yet: #4140 (test added)
All the credit for the fixes goes to `@montrivo.` I only refactored and copy and pasted his code.
changelog: rewrite [`use_self`] lint and fix multiple (8) FPs. One to go.
Fix suggestions that need parens in `from_iter_instead_of_collect` lint
Fixes broken suggestions that need parens (i.e.: range)
Fixes: #6648
changelog: none
This renames the variants in HIR UnOp from
enum UnOp {
UnDeref,
UnNot,
UnNeg,
}
to
enum UnOp {
Deref,
Not,
Neg,
}
Motivations:
- This is more consistent with the rest of the code base where most enum
variants don't have a prefix.
- These variants are never used without the `UnOp` prefix so the extra
`Un` prefix doesn't help with readability. E.g. we don't have any
`UnDeref`s in the code, we only have `UnOp::UnDeref`.
- MIR `UnOp` type variants don't have a prefix so this is more
consistent with MIR types.
- "un" prefix reads like "inverse" or "reverse", so as a beginner in
rustc code base when I see "UnDeref" what comes to my mind is
something like "&*" instead of just "*".
disallowed_methods: Support functions in addition to methods
## Context:
Hey all! I have a particular use case where I'd like to ban certain functions in a code base I work on. For example, I want to ban `Instant::now()` (among others) as we have a time service for mocking time in deterministic simulation tests. Obviously, it doesn't make sense to include a lint like this for all clippy users. Imagine my excitement when I spotted the new `disallowed_methods` lint in clippy--perfect! Unfortunately, after playing around with it for a bit, I was frustrated to realize that it didn't support functions like `Instant::now()`, so I've added support for them in this PR.
It might also make sense to rename the lint from `disallowed_methods` -> `disallowed_functions`, though I've held off from including that rename in this change, since I'm unsure of clippy's breaking change policy.
## Change
Support functions in addition to methods. In other words, support:
`disallowed_methods = ["alloc::vec::Vec::new"]` (a function) in addition to
`disallowed_methods = ["alloc::vec::Vec::leak"]` (a method).
Improve the documentation to clarify that users must specify the full qualified path for each disallowed function, which can be confusing for reexports. Include an example `clippy.toml`.
Simplify the actual lint pass so we can reuse `utils::fn_def_id`.
changelog: disallowed_method: Now supports functions in addition to methods
Add new lint `filter_map_identity`
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This commit adds a new lint named filter_map_identity.
This lint is the same as `flat_map_identity` except that it checks for the usage of `filter_map`.
---
Closes#6643
changelog: Added a new lint: `filter_map_identity`
Adds a new lint that checks if there is a semicolon on the last block statement if it returns nothing
changelog: Added a new lint: `SEMICOLON_IF_NOTHING_RETURNED`
fixes#6467
Adds the `SEMICOLON_IF_NOTHING_RETURNED` lint and therefore closes#6467.
Cleanup path-to-local checks
changelog: none
It seemed like too much ceremony going on to check if an expression matches a variable. So I created two util functions `path_to_local(Expr) -> Option<HirId>` and `path_to_local_id(Expr, HirId) -> bool` to make this easier, and used them wherever applicable.
I changed logic in a few places to use `HirId` instead of `Symbol` where it was easy to do so. I believe this is more correct and may even fix some bugs.
I also removed some calls to `qpath_res`. This is not needed if you are only looking for a `Res::Local`.
As a note, I wanted to name the util functions in a way that encourages understanding of the HIR.
