Tweak irrefutable let else warning output
Fixes https://github.com/rust-lang/rust/issues/153454
Greeting!
This PR tweak diagnostic output for `irrefutable-let-else` patterns and adds a check for `let a = Some(b) else {...}`
Thanks for the review!
```
help: consider using `let Some(name) = case` to match on a specific variant
|
LL - let name = Some(case) else {
LL + let Some(name) = case else {
|
```
Syntactically reject tuple index shorthands in struct patterns to fix a correctness regression
Split out of PR rust-lang/rust#154492. This fixes a correctness regression introduced in PR rust-lang/rust#81235 from 2021. Crater was run in my other PR and didn't report any real regressions (https://github.com/rust-lang/rust/pull/154492#issuecomment-4187544786); a rerun has been issued for a few spurious builds (https://github.com/rust-lang/rust/pull/154492#issuecomment-4237077272) but I'm certain it won't find anything either.
This is a theoretical breaking change that doesn't need any T-lang input IMHO since it's such a minute, niche and crystal clear bug that's not worth bothering them with (such a decision is not unprecedented). I'm adding it to the compatibility section of the release notes as is customary.
The Reference doesn't need updating since it didn't adopt this bug and thus accurately describes this part of the grammar as it used to be before 2021-02-23 and as it's meant to be.
The majority of the diff is doc comment additions & necessary UI test restructurings.
Reject dangling attributes in where clauses
Report `attribute without where predicates` for trailing outer attributes in where clauses.
Closesrust-lang/rust#155073 .
also removes E0452 and splits
`tests/rustdoc-ui/lints/renamed-lint-still-applies` into 2 tests
this is because of delayed warn lint being lost on compiler aborting on
error
Emit pre-expansion feature gate warnings for negative impls and specialization
Follow up to rust-lang/rust#154475; part of rust-lang/rust#154045.
This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](https://github.com/rust-lang/compiler-team/issues/535).
However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](https://github.com/rust-lang/rust/pull/116393#issuecomment-1745571299) that this is a T-compiler matter).
move many tests from `structs-enums` to `structs` or `enum`
This PR moves most of the tests in `ui/structs-enums` that are only about structs or only about enums to their respective directory, as a step towards removing `ui/structs-enums`.
Followup to rust-lang/rust#154131.
r? @Kivooeo
- On `const` and `static` point at the type (like we do for let bindings)
- On fn calls, point at const parameter in fn definition
- On type, point at const parameter in type definition
- On array type lengths, explain that array length is always `usize`
- On enum variant discriminant, mention `repr`
Improve irrefutable let-else lint wording
Update the `irrefutable_let_patterns` wording for let-else to better reflect that the `else` clause is unreachable when the LHS pattern always matches.
Closesrust-lang/rust#152938
Remove unhelpful hint from trivial bound errors
The `= help: see issue #48214` hint on trivial bound errors isn't useful, most users hitting these errors aren't trying to use the `trivial_bounds` feature. The `disabled_nightly_features` call already handles suggesting the feature gate on nightly.
Closesrust-lang/rust#152872
This prevents spurious errors when a field is intended to be present
but a preceding syntax error caused it not to be parsed. For example,
StructName { foo: 1 bar: 2 }
will not successfully parse a field `bar`, and we will report the syntax
error but not the missing field.
Remove "failed to resolve" and use the same format we use in other resolution errors "cannot find `name`".
```
error[E0433]: cannot find `nonexistent` in `existent`
--> $DIR/custom_attr_multisegment_error.rs:5:13
|
LL | #[existent::nonexistent]
| ^^^^^^^^^^^ could not find `nonexistent` in `existent`
```
Implement RFC 3678: Final trait methods
Tracking: https://github.com/rust-lang/rust/issues/131179
This PR is based on rust-lang/rust#130802, with some minor changes and conflict resolution.
Futhermore, this PR excludes final methods from the vtable of a dyn Trait.
And some excerpt from the original PR description:
> Implements the surface part of https://github.com/rust-lang/rfcs/pull/3678.
>
> I'm using the word "method" in the title, but in the diagnostics and the feature gate I used "associated function", since that's more accurate.
cc @joshtriplett
support c-variadic functions in `rustc_const_eval`
tracking issue: https://github.com/rust-lang/rust/issues/44930
The new `GlobalAlloc::VaList` is used to create an `AllocId` that represents the variable argument list of a frame. The allocation itself does not store any data, all we need is the unique identifier.
The actual variable argument list is stored in `Memory`, and keyed by the `AllocId`. The `Frame` also stores this `AllocId`, so that when a frame is popped, it can deallocate the variable arguments.
At "runtime" a `VaList` value stores a pointer to the global allocation in its first bytes. The provenance on this pointer can be used to retrieve its `AllocId`, and the offset of the pointer is used to store the index of the next argument to read from the variable argument list.
Miri does not yet support `va_arg`, but I think that can be done separetely?
r? @RalfJung
cc @workingjubilee
Jonathan Brouwer