Update mgca to use `type const` syntax instead of the `#[type_const]` attribute.
This PR changes the `#[type_const]` attribute to the `type const` syntax for https://github.com/rust-lang/rust/issues/132980.
This will fixes https://github.com/rust-lang/rust/issues/151273 and similar issues, since we need to check `type const` of items before expansion. The move to add a syntax was mentioned here: https://github.com/rust-lang/rust/pull/151289#issuecomment-3765241397
The first part of this PR adds support by allowing `type const <IDENT>: <TYPE> { = <EXPR> };` syntax in `rustc_parse/src/parser/item.rs`.
The next part since the AST item does not contain enough information to determine if we have a `type const` was rework `ConstItemRhs` into `ConstItemRhsKind` to store the information since we no longer have the attribute acting as a source of extra data/metadata.
The hir node `ConstItemRhsKind` current shape mostly works, except in the case of `TraitItemKind` where it is an option. I initially went about giving `hir::ConstItemRhsKind` a similar form the AST, but it touches a lot more lines of code and files so because of that, the less invasive option was to add a simple boolean flag to `TraitItemKind`.
The forth part of this PR includes adding a query I called `is_rhs_type_const` so that we can handle both local and foreign def_ids.
The fifth aspect of the PR is adding a `mgca_type_const_syntax` feature gate that is checked before expansion. The standard mgca feature gate is ran after expansion. This feature gate allows for conditional compilation (e.g #[cfg(..)]) of the `type const` syntax in nightly without `min_generic_const_args` being enabled.
The last bit is updating all the the tests that used the `#[type_const]` attribute to use the new syntax that failed because of the changes. This is the bulk of touched/edited files in the PR.
r? @BoxyUwU
@rustbot label +F-associated_const_equality +F-min_generic_const_args
Revert, but without type const.
Update symbol for feature err, then update suggestion output, and lastly update tests that change because of those.
Update these new tests with the correct syntax, and few existing tests with the new outputs the merge with main added.
Fix for tidyfmt and some errors when manually resolving a merge conflicts.
Update these tests to use update error messages and type const syntax.
Update comments and error message to use new syntax instead of old type_const attribute.
Remove the type_const attribute
update some more tests to use the new syntax.
Update these test cases.
update feature gate test
Change gate logic for `mgca_type_const_syntax` to work also if `min_generic_const_args` is enabled.
Create a new feature gate that checks for the feature before expansion.
Make rustfmt handle the `type const` syntax correctly.
Add a convience method to check if a RhsKind is type const.
Rename `Const` discriminant to `Body` for `ConstItemRhsKind`
Give the `TraitItemKind` flag an enum instead of a simple bool to better describe what the flag is for.
Update formatting for these match statements.
Update clippy test to use type const syntax.
Update test to use type const syntax.
update rustfmt to match ast items.
Update clippy to match ast and hir items.
Few more test cases that used old attribute, instead of 'type const'
Update to match the output from the feature gate checks.
tidyfmt adjustments.
Update the is_type_const, so I can constrain record!(..) in encoder.rs
Update conditional compilation test.
Move the feature gate to after expansion to allow for cfg(...) to work.
Update some more tests to use the new syntax.
Update type const tests in associated-const-bindings to use new syntax.
Don't check based off the attribute, but the item here.
Update some tests outside of the const_generics folder that were using #[type_const]
update the tests in associated consts that use #[type_const] to use type const
Update these mgca tests with the type const syntax.
Add a flag to TraitItemKind for detecting type const for now. Maybe later change ItemConstRhs to have optional consts but that touches a lot more lines of code.
Don't need into for these now that it's a query.
Add is_type_const query to handle foreign def ids.
update this test to use type const syntax.
Fix logic here, we only want to lower if there is expression in this case.
Update built-in macros to use ConstItemRhsKind
Update more instance of the old ConstItemRhs.
Rename ConstItemKind to ConstItemRhsKind, I noticed there is a typed called ConstantItemKind, so add the Rhs to the name to avoid confusion.
Update lower to use ConstItemKind
Add an other helper method to check if the rhs kinda has an expr.
Update item parse to use ConstItemKind enum.
Felt the field name could a be little clear when editing a few other things.
Change the ConstItem struct see know if we have a type const or regular const.
Make sure this syntax is properly feature gated.
Add message format checking
Checks the indentation of diagnostic messages, it checks that everything is at least as indented as the attribute that contains it
r? @jdonszelmann (Anyone else, also feel free to review, just assigning to Jana because she's been reviewing the other PRs)
Implement MVP for opaque generic const arguments
This is meant to be the interim successor to generic const expressions.
Essentially, const item RHS's will be allowed to do arbitrary const
operations using generics. The limitation is that these const items will
be treated opaquely, like ADTs in nominal typing, such that uses of them
will only be equal if the same const item is referenced. In other words,
two const items with the exact same RHS will not be considered equal.
I also added some logic to check feature gates that depend on others
being enabled (like oGCA depending on mGCA).
### Coherence
During coherence, OGCA consts should be normalized ambiguously because
they are opaque but eventually resolved to a real value. We don't want
two OGCAs that have the same value to be treated as distinct for
coherence purposes. (Just like opaque types.)
This actually doesn't work yet because there are pre-existing
fundamental issues with equate relations involving consts that need to
be normalized. The problem is that we normalize only one layer of the
const item and don't actually process the resulting anon const. Normally
the created inference variable should be handled, which in this case
would cause us to hit the anon const, but that's not happening.
Specifically, `visit_const` on `Generalizer` should be updated to be
similar to `visit_ty`.
r? @BoxyUwU
Fix a few diagnostics
When working on the inline diagnostics conversion (https://github.com/rust-lang/rust/issues/151366), I noticed that my script sometimes took the wrong message.
Because it didn't happen very often, I just fixed it manually when a uitest fails.
However I got paranoid that the script changed messages that were not covered by uitests, so I checked for all messages in the previous `messages.ftl` files, whether they occured at least once in the codebase. I found 3 messages that indeed were wrongly replaced by my script, fixed them, and added uitests to make sure this doesn't happen again :)
r? @jdonszelmann (Anyone else, also feel free to review, just assigning to Jana because she's been reviewing the other PRs)
This is meant to be the interim successor to generic const expressions.
Essentially, const item RHS's will be allowed to do arbitrary const
operations using generics. The limitation is that these const items will
be treated opaquely, like ADTs in nominal typing, such that uses of them
will only be equal if the same const item is referenced. In other words,
two const items with the exact same RHS will not be considered equal.
I also added some logic to check feature gates that depend on others
being enabled (like oGCA depending on mGCA).
= Coherence =
During coherence, OGCA consts should be normalized ambiguously because
they are opaque but eventually resolved to a real value. We don't want
two OGCAs that have the same value to be treated as distinct for
coherence purposes. (Just like opaque types.)
This actually doesn't work yet because there are pre-existing
fundamental issues with equate relations involving consts that need to
be normalized. The problem is that we normalize only one layer of the
const item and don't actually process the resulting anon const. Normally
the created inference variable should be handled, which in this case
would cause us to hit the anon const, but that's not happening.
Specifically, `visit_const` on `Generalizer` should be updated to be
similar to `visit_ty`.
Support long diff conflict markers
git can be configured to use more than 7 characters for conflict markers, and jj automatically uses longer conflict markers when the text contains any char sequence that could be confused with conflict markers. Ensure that we only point at markers that are consistent with the start marker's length.
Ensure that we only consider char sequences at the beginning of a line as a diff marker.
Fix https://github.com/rust-lang/rust/issues/150352.
Feature-gate `mut ref` patterns in struct pattern field shorthand
Tracking issue for `mut_ref` (and other parts of Match Ergonomics 2024): https://github.com/rust-lang/rust/issues/123076https://github.com/rust-lang/rust/pull/123080 introduced `mut ref`[^1] patterns (for by-reference bindings where the binding itself is mutable), feature-gated behind the `mut_ref` feature, except for in struct pattern shorthand, where the feature gating was missing. Thus, `mut ref` patterns in struct pattern shorthand has been unintentionally stable for ~18 months (since 1.79.0 ([compiler explorer](https://rust.godbolt.org/z/4WTrvhboT))).
This PR adds feature-gating for `mut ref` patterns in struct pattern shorthand. Since this is reverting an accidental stabilization, this probably needs a crater run and a T-lang FCP?
Some alternative possibilities:
* Do nothing (let the inconsistency exist until `feature(mut_ref)` is stabilized)
* Document the existing behavior
* Do a FCW instead of fully feature-gating
* Stabilize `feature(mut_ref)`
CC https://github.com/rust-lang/rust/pull/123080#issuecomment-3746793632
CC @Nadrieril
[^1]: everything in this description also applies analogously to `mut ref mut` patterns.
fix(parser): Disallow CR in frontmatter
T-lang came back on the stabilization PR (rust-lang/rust#148051) asking for CR to be disallowed
to leave room for all stray CRs to be rejected in the future.
At that point, the test can remain but the implementation can be
removed.
If that plan does not go through, we'll need to re-evaluate
- whether this is more lint-like and should defer to the calling tool
that is managing the frontmatter
- how much Rust should treat the frontmatter as Rust and apply the same
grammar restrictions of "no stray CR" (like raw string literals)
Part of rust-lang/rust#136889
T-lang came back on the stabilization PR asking for CR to be disallowed
to leave room for all stray CRs to be rejected in the future.
At that point, the test can remain but the implementation can be
removed.
If that plan does not go through, we'll need to re-evaluate
- whether this is more lint-like and should defer to the calling tool
that is managing the frontmatter
- how much Rust should treat the frontmatter as Rust and apply the same
grammar restrictions of "no stray CR" (like raw string literals)
From the `parser` module to the `errors` module, which is where most of
its uses are.
This means the `errors` module no longer depends on the `parser` module,
removing a cyclic dependency between the two modules.
Every diagnostic struct in `rustc_parse` is in the `errors` module,
except for `ForbiddenLetReason` and `MisspelledKw`. There's no good
reason for this, and presumably it is just an accidental inconsistency.
This commit moves them into `errors`.
Based on earlier work by León Orell Valerian Liehr.
Co-authored-by: León Orell Valerian Liehr <me@fmease.dev>
Signed-off-by: Usman Akinyemi <uniqueusman@archlinux>
`const` blocks as a `mod` item
Tracking issue: rust-lang/rust#149226
This adds support for writing `const { ... }` as an item in a module. In the current implementation, this is a unique AST item that gets lowered to `const _: () = const { ... };` in HIR.
rustfmt support included.
TODO:
- `pub const { ... }` does not make sense (see rust-lang/rust#147136). Reject it. Should this be rejected by the parser or smth?
- Improve diagnostics (preferably they should not mention the fake `_` ident).
Do not recover from `Trait()` if generic list is unterminated
If we encounter `fn foo<T: Trait()`, the recovery logic would it as if `Trait` was intended to use the Fn-like trait syntax, but if we don't know for certain that we've parsed a full trait bound (`fn foo<T: Trait()>`), we bail from the recovery as more likely there could have been a missing closing `>` and the `(` corresponds to the start of the fn parameter list.
Fixrust-lang/rust#141436.
If we encounter `fn foo<T: Trait()`, the recovery logic would it as if `Trait` was intended to use the Fn-like trait syntax, but if we don't know for certain that we've parsed a full trait bound (`fn foo<T: Trait()>`), we bail from the recovery as more likely there could have been a missing closing `>` and the `(` corresponds to the start of the fn parameter list.
