Don't call `query_normalize` when reporting similar impls
Firstly, It's sketchy to be using `query_normalize` at all during HIR typeck -- it's asking for an ICE 😅. Secondly, we're normalizing an impl trait ref that potentially has parameter types in `ty::ParamEnv::empty()`, which is kinda sketchy as well.
The only UI test change from removing this normalization is that we don't evaluate anonymous constants in impls, which end up giving us really ugly suggestions:
```
error[E0277]: the trait bound `[X; 35]: Default` is not satisfied
--> /home/gh-compiler-errors/test.rs:4:5
|
4 | <[X; 35] as Default>::default();
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Default` is not implemented for `[X; 35]`
|
= help: the following other types implement trait `Default`:
&[T]
&mut [T]
[T; 32]
[T; core::::array::{impl#30}::{constant#0}]
[T; core::::array::{impl#31}::{constant#0}]
[T; core::::array::{impl#32}::{constant#0}]
[T; core::::array::{impl#33}::{constant#0}]
[T; core::::array::{impl#34}::{constant#0}]
and 27 others
```
So just fold the impls with a `BottomUpFolder` that calls `ty::Const::eval`. This doesn't work totally correctly with generic-const-exprs, but it's fine for stable code, and this is error reporting after all.
tests: unset `RUSTC_LOG_COLOR` in a test
Setting `RUSTC_LOG_COLOR=always` is sometimes useful if tools that one pipes `RUSTC_LOG` into support coloured output, but it makes this test fail because it has a `.stderr` file with `WARN` log output.
Setting `RUSTC_LOG_COLOR=always` is sometimes useful if tools that one
pipes `RUSTC_LOG` into support coloured output, but it makes this test
fail.
Signed-off-by: David Wood <david@davidtw.co>
- Either explicitly annotate `let x: () = expr;` where `x` has unit
type, or remove the unit binding to leave only `expr;` instead.
- Fix disjoint-capture-in-same-closure test
When constant evaluation fails because its MIR is tainted by errors,
suppress note indicating that erroneous constant was used, since those
errors have to be fixed regardless of the constant being used or not.
Uplift `clippy::{drop,forget}_{ref,copy}` lints
This PR aims at uplifting the `clippy::drop_ref`, `clippy::drop_copy`, `clippy::forget_ref` and `clippy::forget_copy` lints.
Those lints are/were declared in the correctness category of clippy because they lint on useless and most probably is not what the developer wanted.
## `drop_ref` and `forget_ref`
The `drop_ref` and `forget_ref` lint checks for calls to `std::mem::drop` or `std::mem::forget` with a reference instead of an owned value.
### Example
```rust
let mut lock_guard = mutex.lock();
std::mem::drop(&lock_guard) // Should have been drop(lock_guard), mutex
// still locked
operation_that_requires_mutex_to_be_unlocked();
```
### Explanation
Calling `drop` or `forget` on a reference will only drop the reference itself, which is a no-op. It will not call the `drop` or `forget` method on the underlying referenced value, which is likely what was intended.
## `drop_copy` and `forget_copy`
The `drop_copy` and `forget_copy` lint checks for calls to `std::mem::forget` or `std::mem::drop` with a value that derives the Copy trait.
### Example
```rust
let x: i32 = 42; // i32 implements Copy
std::mem::forget(x) // A copy of x is passed to the function, leaving the
// original unaffected
```
### Explanation
Calling `std::mem::forget` [does nothing for types that implement Copy](https://doc.rust-lang.org/std/mem/fn.drop.html) since the value will be copied and moved into the function on invocation.
-----
Followed the instructions for uplift a clippy describe here: https://github.com/rust-lang/rust/pull/99696#pullrequestreview-1134072751
cc `@m-ou-se` (as T-libs-api leader because the uplifting was discussed in a recent meeting)
check array type of repeat exprs is wf
Fixes#111091
Also makes sure that we actually renumber regions in the length of repeat exprs which we previously weren't doing and would cause ICEs in `adt_const_params` + `generic_const_exprs` from attempting to prove the wf goals when the length was an unevaluated constant with `'erased` in the `ty` field of `Const`
The duplicate errors are caused by the fact that `const_arg_to_const`/`array_len_to_const` in `FnCtxt` adds a `WellFormed` goal for the created `Const` which is also checked by the added `WellFormed(array_ty)`. I don't want to change this to just emit a `T: Sized` goal for the element type since that would ignore `ConstArgHasType` wf requirements and generally uncomfortable with the idea of trying to sync up `wf::obligations` for arrays and the code in hir typeck for repeat exprs.
r? `@compiler-errors`
Explicitly reject negative and reservation drop impls
Fixes#110858
It doesn't really make sense for a type to have a `!Drop` impl. Or at least, I don't want us to implicitly assign a meaning to it by the way the compiler *currently* handles it (incompletely), and rather I would like to see a PR (or an RFC...) assign a meaning to `!Drop` if we actually wanted one for it.
My type ascription
Oh rip it out
Ah
If you think we live too much then
You can sacrifice diagnostics
Don't mix your garbage
Into my syntax
So many weird hacks keep diagnostics alive
Yet I don't even step outside
So many bad diagnostics keep tyasc alive
Yet tyasc doesn't even bother to survive!
Add suggestion to use closure argument instead of a capture on borrowck error
Fixes#109271
r? `@compiler-errors`
This should probably be refined a bit, but opening a PR so that I don't forget anything.
Check pattern refutability on THIR
The current `check_match` query is based on HIR, but partially re-lowers HIR into THIR.
This PR proposed to use the results of the `thir_body` query to check matches, instead of re-building THIR.
Most of the diagnostic changes are spans getting shorter, or commas/semicolons not getting removed.
This PR degrades the diagnostic for confusing constants in patterns (`let A = foo()` where `A` resolves to a `const A` somewhere): it does not point ot the definition of `const A` any more.
Use span of placeholders in format_args!() expansion.
`format_args!("{}", x)` expands to something that contains `Argument::new_display(&x)`. That entire expression was generated with the span of `x`.
After this PR, `&x` uses the span of `x`, but the `new_display` call uses the span of the `{}` placeholder within the format string. If an implicitly captured argument was used like in `format_args!("{x}")`, both use the span of the `{x}` placeholder.
This fixes https://github.com/rust-lang/rust/issues/109576, and also allows for more improvements to similar diagnostics in the future, since the usage of `x` can now be traced to the exact `{}` placeholder that required it to be `Display` (or `Debug` etc.)
Move const trait bounds checks to MIR constck
Fixes#109543. When checking paths in HIR typeck, we don't want to check for const predicates since all we want might just be a function pointer. Therefore we move this to MIR constck and check that bounds are met during MIR constck.
r? `@oli-obk`
