Matthias Krüger 1fd0c71818 Rollup merge of #120221 - compiler-errors:statements-are-not-patterns, r=nnethercote ...

Don't make statement nonterminals match pattern nonterminals

Right now, the heuristic we use to check if a token may begin a pattern nonterminal falls back to `may_be_ident`:
https://github.com/rust-lang/rust/blob/ef71f1047e04438181d7cb925a833e2ada6ab390/compiler/rustc_parse/src/parser/nonterminal.rs#L21-L37

This has the unfortunate side effect that a `stmt` nonterminal eagerly matches against a `pat` nonterminal, leading to a parse error:
```rust
macro_rules! m {
    ($pat:pat) => {};
    ($stmt:stmt) => {};
}

macro_rules! m2 {
    ($stmt:stmt) => {
        m! { $stmt }
    };
}

m2! { let x = 1 }
```

This PR fixes it by more accurately reflecting the set of nonterminals that may begin a pattern nonterminal.

As a side-effect, I modified `Token::can_begin_pattern` to work correctly and used that in `Parser::nonterminal_may_begin_with`.

2024-08-31 10:08:51 +02:00

..

src

Rollup merge of #120221 - compiler-errors:statements-are-not-patterns, r=nnethercote

2024-08-31 10:08:51 +02:00

Cargo.toml

Move some tests from rustc_expand to rustc_parse.

2024-05-06 09:06:02 +10:00

messages.ftl

Rollup merge of #128496 - clubby789:box-syntax-multipart, r=compiler-errors

2024-08-01 18:43:41 +02:00