The rustc AST allows both `for<>` binders and `?` polarity
modifiers in trait bounds, but they are parsed in a specific
order and validated for correctness:
1. `for<>` binder is parsed first.
2. Polarity modifiers (`?`, `!`) are parsed second.
3. The parser validates that binders and polarity modifiers
do not conflict:
```rust
if let Some(binder_span) = binder_span {
match modifiers.polarity {
BoundPolarity::Maybe(polarity_span) => {
// Error: "for<...> binder not allowed with ? polarity"
}
}
}
```
This implies:
- `for<> ?Sized` → Valid syntax. Invalid semantics.
- `?for<> Sized` → Invalid syntax.
However, rust-analyzer incorrectly had special-case logic that
allowed `?for<>` as valid syntax. This fix removes that incorrect
special case, making rust-analyzer reject `?for<> Sized` as a
syntax error, matching rustc behavior.
This has caused confusion in other crates (such as syn) which
rely on these files to implement correct syntax evaluation.
Even when at curly braces, otherwise the parser can get stuck.
This has happened in the past in #18625, but it was just worked around instead of handling the root of the problem. Now this happened again in #20171. IMO we can't let `err_and_bump()` not bump, that's too confusing and invites errors. We can (as I did) workaround the worse recovery instead.
Including:
- Infer `label {}` and `const` operands.
- Correctly handle unsafe check inside `label {}`.
- Fix an embarrassing parser typo that cause labels to never be part of the AST
A new syntax node `ast::VariantDef` has been introduced to map between the HIR node and the AST.
The files have been updated with `cargo test -p xtask`.
Signed-off-by: Prajwal S N <prajwalnadig21@gmail.com>
Split manual.adoc into markdown files, one for each chapter.
For the parts of the manual that are generated from source code doc
comments, update the comments to use markdown syntax and update the
code generators to write to `generated.md` files.
For the weekly release, stop copying the .adoc files to the
`rust-analyzer/rust-analyzer.github.io` at release time. Instead,
we'll sync the manual hourly from this repository.
See https://github.com/rust-analyzer/rust-analyzer.github.io/pull/226
for the sync. This PR should be merged first, and that PR needs to be
merged before the next weekly release.
This change is based on #15795, but rebased and updated. I've also
manually checked each page for markdown syntax issues and fixed any I
encountered.
Co-authored-by: Lukas Wirth <lukastw97@gmail.com>
Co-authored-by: Josh Rotenberg <joshrotenberg@gmail.com>
