[`unnecessary_to_owned`]: catch `to_owned` on byte slice to create temporary `&str`
Closes#11648
Detects the pattern `&String::from_utf8(bytes.to_vec()).unwrap()` and suggests `core::str::from_utf8(bytes).unwrap()`, which avoids the unnecessary intermediate allocation.
I decided to put this in the existing `unnecessary_to_owned` lint (rather than creating a new lint) for a few reasons:
- we get to use some of its logic (for example, recognizing any of the functions in the `to_owned` family, e.g. `to_vec`)
- the actual inefficient operation that can be avoided here is the call to `.to_vec()`, so this is in a way similar to the other cases caught by `unnecessary_to_owned`, just through a bunch of type conversions
- we can make this more "generic" later and catch other cases, so imo it's best not to tie this lint specifically to the `String` type
changelog: [`unnecessary_to_owned`]: catch `&String::from_utf8(bytes.to_vec()).unwrap()` and suggest `core::str::from_utf8(bytes).unwrap()`
Fix some false-positive cases of `explicit_auto_deref`
changelog: [`explicit_auto_deref`] Fix some false-positive cases
Fix part of #9841
Fix #12969
r? xFrednet
Don't lint `assertions_on_constants` on any const assertions
close#12816close#12847
cc #12817
----
changelog: Fix false positives in consts for `assertions_on_constants` and `unnecessary_operation`.
resolve `clippy::invalid_paths` on `bool::then`
*Please write a short comment explaining your change (or "none" for internal only changes)*
changelog: none
This removes the ICE codepaths for `f16` and `f128` in Clippy.
`rustc_apfloat` is used as a dependency for the parsing of these types,
since their `FromStr` implementation will not be available in the
standard library for a while.
Add more types to `is_from_proc_macro`
I've been running through going through all the lint implementations to clean them up. I'll be separating out the changes into small PRs to make reviewing easier.
changelog: none
* Delay the parsing of the use node
* Mark when the `SyntaxContext` changes rather than return `None`
* Return a default value if the HIR tree is broken rather than `None`
Avoid emitting `assigning_clones` when cloned data borrows from the place to clone into
Fixes#12444Fixes#12460Fixes#12749Fixes#12757Fixes#12929
I think the documentation for the function should describe what- and how this is fixing the issues well.
It avoids emitting a warning when the data being cloned borrows from the place to clone into, which is information that we can get from `PossibleBorrowerMap`. Unfortunately, it is a tiny bit tedious to match on the MIR like that and I'm not sure if this is possibly relying a bit too much on the exact MIR lowering for assignments.
Things left to do:
- [x] Handle place projections (or verify that they work as expected)
- [x] Handle non-`Drop` types
changelog: [`assigning_clones`]: avoid warning when the suggestion would lead to a borrow-check error
Let `qualify_min_const_fn` deal with drop terminators
Fixes#12677
The `method_accepts_droppable` check that was there seemed overly conservative.
> Returns true if any of the method parameters is a type that implements `Drop`.
> The method can't be made const then, because `drop` can't be const-evaluated.
Accepting parameters that implement `Drop` should still be fine as long as the parameter isn't actually dropped, as is the case in the linked issue where the droppable is moved into the return place. This more accurate analysis ("is there a `drop` terminator") is already done by `qualify_min_const_fn` [here](f5e250180c/clippy_utils/src/qualify_min_const_fn.rs (L298)), so I don't think this additional check is really necessary?
Fixing the other, second case in the linked issue was only slightly more involved, since `Vec::new()` is a function call that has the ability to panic, so there must be a `drop()` terminator for cleanup, however we should be able to freely ignore that. [Const checking ignores cleanup blocks](https://github.com/rust-lang/rust/blob/master/compiler/rustc_const_eval/src/transform/check_consts/check.rs#L382-L388), so we should, too?
r? `@Jarcho`
----
changelog: [`missing_const_for_fn`]: continue linting on fns with parameters implementing `Drop` if they're not actually dropped
Make `for_each_expr` visit closures by default, rename the old version `for_each_expr_without_closures`
A lot of the time `for_each_expr` is picked when closures should be visited so I think it makes sense for this to be the default with the alternative available for when you don't need to visit them.
The first commit renames `for_each_expr` to `for_each_expr_without_closures` and `for_each_expr_with_closures` to `for_each_expr`
The second commit switches a few uses that I caught over to include closures to fix a few bugs
changelog: none
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
Rename HIR `TypeBinding` to `AssocItemConstraint` and related cleanup
Rename `hir::TypeBinding` and `ast::AssocConstraint` to `AssocItemConstraint` and update all items and locals using the old terminology.
Motivation: The terminology *type binding* is extremely outdated. "Type bindings" not only include constraints on associated *types* but also on associated *constants* (feature `associated_const_equality`) and on RPITITs of associated *functions* (feature `return_type_notation`). Hence the word *item* in the new name. Furthermore, the word *binding* commonly refers to a mapping from a binder/identifier to a "value" for some definition of "value". Its use in "type binding" made sense when equality constraints (e.g., `AssocTy = Ty`) were the only kind of associated item constraint. Nowadays however, we also have *associated type bounds* (e.g., `AssocTy: Bound`) for which the term *binding* doesn't make sense.
---
Old terminology (HIR, rustdoc):
```
`TypeBinding`: (associated) type binding
├── `Constraint`: associated type bound
└── `Equality`: (associated) equality constraint (?)
├── `Ty`: (associated) type binding
└── `Const`: associated const equality (constraint)
```
Old terminology (AST, abbrev.):
```
`AssocConstraint`
├── `Bound`
└── `Equality`
├── `Ty`
└── `Const`
```
New terminology (AST, HIR, rustdoc):
```
`AssocItemConstraint`: associated item constraint
├── `Bound`: associated type bound
└── `Equality`: associated item equality constraint OR associated item binding (for short)
├── `Ty`: associated type equality constraint OR associated type binding (for short)
└── `Const`: associated const equality constraint OR associated const binding (for short)
```
r? compiler-errors
