diff options
| author | Michael Goulet <michael@errs.io> | 2023-05-10 23:00:47 +0000 |
|---|---|---|
| committer | Michael Goulet <michael@errs.io> | 2023-05-15 17:14:59 +0000 |
| commit | a5763ff8d3e67c156ebe8160de1db26a644d4c5d (patch) | |
| tree | 7ed43464a4909c0c7547136f7ceb4b0267ff3cef | |
| parent | 2913ad6db0f72fed5139253faed73200c7af3535 (diff) | |
| download | rust-a5763ff8d3e67c156ebe8160de1db26a644d4c5d.tar.gz rust-a5763ff8d3e67c156ebe8160de1db26a644d4c5d.zip | |
Recover `impl<T ?Sized>` correctly
| -rw-r--r-- | compiler/rustc_parse/src/parser/generics.rs | 5 | ||||
| -rw-r--r-- | tests/ui/parser/impl-on-unsized-typo.rs | 6 | ||||
| -rw-r--r-- | tests/ui/parser/impl-on-unsized-typo.stderr | 8 |
3 files changed, 19 insertions, 0 deletions
diff --git a/compiler/rustc_parse/src/parser/generics.rs b/compiler/rustc_parse/src/parser/generics.rs index e6d0f9fbc76..cd779b0b43e 100644 --- a/compiler/rustc_parse/src/parser/generics.rs +++ b/compiler/rustc_parse/src/parser/generics.rs @@ -453,6 +453,8 @@ impl<'a> Parser<'a> { // `<` (LIFETIME|IDENT) `:` - generic parameter with bounds // `<` (LIFETIME|IDENT) `=` - generic parameter with a default // `<` const - generic const parameter + // `<` IDENT `?` - RECOVERY for `impl<T ?Bound` missing a `:`, meant to + // avoid the `T?` to `Option<T>` recovery for types. // The only truly ambiguous case is // `<` IDENT `>` `::` IDENT ... // we disambiguate it in favor of generics (`impl<T> ::absolute::Path<T> { ... }`) @@ -463,6 +465,9 @@ impl<'a> Parser<'a> { || self.look_ahead(start + 1, |t| t.is_lifetime() || t.is_ident()) && self.look_ahead(start + 2, |t| { matches!(t.kind, token::Gt | token::Comma | token::Colon | token::Eq) + // Recovery-only branch -- this could be removed, + // since it only affects diagnostics currently. + || matches!(t.kind, token::Question) }) || self.is_keyword_ahead(start + 1, &[kw::Const])) } diff --git a/tests/ui/parser/impl-on-unsized-typo.rs b/tests/ui/parser/impl-on-unsized-typo.rs new file mode 100644 index 00000000000..e09c0463045 --- /dev/null +++ b/tests/ui/parser/impl-on-unsized-typo.rs @@ -0,0 +1,6 @@ +trait Tr {} + +impl<T ?Sized> Tr for T {} +//~^ ERROR expected one of `,`, `:`, `=`, or `>`, found `?` + +fn main() {} diff --git a/tests/ui/parser/impl-on-unsized-typo.stderr b/tests/ui/parser/impl-on-unsized-typo.stderr new file mode 100644 index 00000000000..23dcc1efd68 --- /dev/null +++ b/tests/ui/parser/impl-on-unsized-typo.stderr @@ -0,0 +1,8 @@ +error: expected one of `,`, `:`, `=`, or `>`, found `?` + --> $DIR/impl-on-unsized-typo.rs:3:8 + | +LL | impl<T ?Sized> Tr for T {} + | ^ expected one of `,`, `:`, `=`, or `>` + +error: aborting due to previous error + |