syntax: cleanup param, method, and misc parsing
Do some misc cleanup of the parser:
- Method and parameter parsing is refactored.
- A parser for `const | mut` is introduced that https://github.com/rust-lang/rust/pull/64588 can reuse.
- Some other misc parsing.
Next up in a different PR:
- ~Implementing https://github.com/rust-lang/rust/issues/64252.~ -- maybe some other time...
- Heavily restructuring up `item.rs` which is a mess (hopefully, no promises ^^).
r? @petrochenkov
BTreeSet intersection, is_subset & difference optimizations
...based on the range of values contained; in particular, a massive improvement when these ranges are disjoint (or merely touching), like in the neg-vs-pos benchmarks already in liballoc. Inspired by #64383 but none of the ideas there worked out.
I introduced another variant in IntersectionInner and in DifferenceInner, because I couldn't find a way to initialize these iterators as empty if there's no empty set around.
Also, reduced the size of "large" sets in test cases - if Miri can't handle it, it was needlessly slowing down everyone.
Rollup of 10 pull requests
Successful merges:
- #63674 (syntax: Support modern attribute syntax in the `meta` matcher)
- #63931 (Stabilize macros in some more positions)
- #64887 (syntax: recover trailing `|` in or-patterns)
- #64895 (async/await: improve not-send errors)
- #64896 (Remove legacy grammar)
- #64907 (A small amount of tidying-up factored out from PR #64648)
- #64928 (Add tests for some issues)
- #64930 (Silence unreachable code lint from await desugaring)
- #64935 (Improve code clarity)
- #64937 (Deduplicate closure type errors)
Failed merges:
r? @ghost
Deduplicate closure type errors
Closure typing obligations flow in both direcitons to properly infer
types. Because of this, we will get 2 type errors whenever there's
an unfulfilled obligation. To avoid this, we deduplicate them in the
`InferCtxt`.
Silence unreachable code lint from await desugaring
Fixes#61798.
This PR silences the unreachable code lint when it originates from within an await desugaring.
A small amount of tidying-up factored out from PR #64648
As requested by @Mark-Simulacrum, I put this in a separate commit to make it easier to review. (As far as I can tell, no violations of the policy here, and they are simply in a separate PR because they're not directly related to the import of that PR.)
r? @Mark-Simulacrum
Remove legacy grammar
Revival of #50835 & #55545
On the #wg-grammar discord there was agreement that enough progress has been made to be able to remove the legacy grammar.
r? @Centril @qmx
cc @rust-lang/wg-grammar
async/await: improve not-send errors
cc #64130.
```
note: future does not implement `std::marker::Send` because this value is used across an await
--> $DIR/issue-64130-non-send-future-diags.rs:15:5
|
LL | let g = x.lock().unwrap();
| - has type `std::sync::MutexGuard<'_, u32>`
LL | baz().await;
| ^^^^^^^^^^^ await occurs here, with `g` maybe used later
LL | }
| - `g` is later dropped here
```
r? @nikomatsakis
syntax: recover trailing `|` in or-patterns
Fixes https://github.com/rust-lang/rust/issues/64879.
For example (this also shows that we are sensitive to the typo `||`):
```
error: a trailing `|` is not allowed in an or-pattern
--> $DIR/remove-leading-vert.rs:33:11
|
LL | A || => {}
| - ^^ help: remove the `||`
| |
| while parsing this or-pattern starting here
|
= note: alternatives in or-patterns are separated with `|`, not `||`
```
r? @estebank
syntax: Support modern attribute syntax in the `meta` matcher
Where "modern" means https://github.com/rust-lang/rust/pull/57367:
```
PATH
PATH `(` TOKEN_STREAM `)`
PATH `[` TOKEN_STREAM `]`
PATH `{` TOKEN_STREAM `}`
```
Unfortunately, `meta` wasn't future-proofed using the `FOLLOW` token set like other matchers (https://github.com/rust-lang/rust/issues/34011), so code like `$meta:meta {` or `$meta:meta [` may break, and we need a crater run to find out how often this happens in practice.
Closes https://github.com/rust-lang/rust/issues/49629 (by fully supporting `meta` rather than removing it.)
