diff options
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 40 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 58 | ||||
| -rw-r--r-- | tests/ui/parser/issues/issue-87086-colon-path-sep.rs | 3 | ||||
| -rw-r--r-- | tests/ui/parser/issues/issue-87086-colon-path-sep.stderr | 20 | ||||
| -rw-r--r-- | tests/ui/parser/type-ascription-in-pattern.rs | 17 | ||||
| -rw-r--r-- | tests/ui/parser/type-ascription-in-pattern.stderr | 80 |
6 files changed, 95 insertions, 123 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index a28af7833c3..a9fbd0fa33d 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -2748,28 +2748,7 @@ impl<'a> Parser<'a> { if token::Colon != self.token.kind { return first_pat; } - if !matches!(first_pat.kind, PatKind::Ident(_, _, None) | PatKind::Path(..)) - || !self.look_ahead(1, |token| token.is_non_reserved_ident()) - { - let mut snapshot_type = self.create_snapshot_for_diagnostic(); - snapshot_type.bump(); // `:` - match snapshot_type.parse_ty() { - Err(inner_err) => { - inner_err.cancel(); - } - Ok(ty) => { - let Err(mut err) = self.expected_one_of_not_found(&[], &[]) else { - return first_pat; - }; - err.span_label(ty.span, "specifying the type of a pattern isn't supported"); - self.restore_snapshot(snapshot_type); - let span = first_pat.span.to(ty.span); - first_pat = self.mk_pat(span, PatKind::Wild); - err.emit(); - } - } - return first_pat; - } + // The pattern looks like it might be a path with a `::` -> `:` typo: // `match foo { bar:baz => {} }` let colon_span = self.token.span; @@ -2857,7 +2836,13 @@ impl<'a> Parser<'a> { Applicability::MaybeIncorrect, ); } else { - first_pat = self.mk_pat(new_span, PatKind::Wild); + first_pat = self.mk_pat( + new_span, + PatKind::Err( + self.dcx() + .span_delayed_bug(colon_span, "recovered bad path pattern"), + ), + ); } self.restore_snapshot(snapshot_pat); } @@ -2870,7 +2855,14 @@ impl<'a> Parser<'a> { err.span_label(ty.span, "specifying the type of a pattern isn't supported"); self.restore_snapshot(snapshot_type); let new_span = first_pat.span.to(ty.span); - first_pat = self.mk_pat(new_span, PatKind::Wild); + first_pat = + self.mk_pat( + new_span, + PatKind::Err(self.dcx().span_delayed_bug( + colon_span, + "recovered bad pattern with type", + )), + ); } } err.emit(); diff --git a/compiler/rustc_parse/src/parser/expr.rs b/compiler/rustc_parse/src/parser/expr.rs index 81a5d48d94e..8046abcd70b 100644 --- a/compiler/rustc_parse/src/parser/expr.rs +++ b/compiler/rustc_parse/src/parser/expr.rs @@ -3612,7 +3612,7 @@ impl<'a> Parser<'a> { self.token.is_keyword(kw::Async) && self.is_gen_block(kw::Gen, 1) } - fn is_certainly_not_a_block(&self) -> bool { + fn is_likely_struct_lit(&self) -> bool { // `{ ident, ` and `{ ident: ` cannot start a block. self.look_ahead(1, |t| t.is_ident()) && self.look_ahead(2, |t| t == &token::Comma || t == &token::Colon) @@ -3624,24 +3624,50 @@ impl<'a> Parser<'a> { path: &ast::Path, ) -> Option<PResult<'a, Box<Expr>>> { let struct_allowed = !self.restrictions.contains(Restrictions::NO_STRUCT_LITERAL); - if struct_allowed || self.is_certainly_not_a_block() { - if let Err(err) = self.expect(exp!(OpenBrace)) { - return Some(Err(err)); + match (struct_allowed, self.is_likely_struct_lit()) { + // A struct literal isn't expected and one is pretty much assured not to be present. The + // only situation that isn't detected is when a struct with a single field was attempted + // in a place where a struct literal wasn't expected, but regular parser errors apply. + // Happy path. + (false, false) => None, + (true, _) => { + // A struct is accepted here, try to parse it and rely on `parse_expr_struct` for + // any kind of recovery. Happy path. + if let Err(err) = self.expect(exp!(OpenBrace)) { + return Some(Err(err)); + } + Some(self.parse_expr_struct(qself.clone(), path.clone(), true)) } - let expr = self.parse_expr_struct(qself.clone(), path.clone(), true); - if let (Ok(expr), false) = (&expr, struct_allowed) { - // This is a struct literal, but we don't can't accept them here. - self.dcx().emit_err(errors::StructLiteralNotAllowedHere { - span: expr.span, - sub: errors::StructLiteralNotAllowedHereSugg { - left: path.span.shrink_to_lo(), - right: expr.span.shrink_to_hi(), - }, - }); + (false, true) => { + // We have something like `match foo { bar,` or `match foo { bar:`, which means the + // user might have meant to write a struct literal as part of the `match` + // discriminant. This is done purely for error recovery. + let snapshot = self.create_snapshot_for_diagnostic(); + if let Err(err) = self.expect(exp!(OpenBrace)) { + return Some(Err(err)); + } + match self.parse_expr_struct(qself.clone(), path.clone(), false) { + Ok(expr) => { + // This is a struct literal, but we don't accept them here. + self.dcx().emit_err(errors::StructLiteralNotAllowedHere { + span: expr.span, + sub: errors::StructLiteralNotAllowedHereSugg { + left: path.span.shrink_to_lo(), + right: expr.span.shrink_to_hi(), + }, + }); + Some(Ok(expr)) + } + Err(err) => { + // We couldn't parse a valid struct, rollback and let the parser emit an + // error elsewhere. + err.cancel(); + self.restore_snapshot(snapshot); + None + } + } } - return Some(expr); } - None } pub(super) fn parse_struct_fields( diff --git a/tests/ui/parser/issues/issue-87086-colon-path-sep.rs b/tests/ui/parser/issues/issue-87086-colon-path-sep.rs index d081c06044f..e1ea38f2795 100644 --- a/tests/ui/parser/issues/issue-87086-colon-path-sep.rs +++ b/tests/ui/parser/issues/issue-87086-colon-path-sep.rs @@ -37,10 +37,9 @@ fn g1() { //~| HELP: maybe write a path separator here _ => {} } - if let Foo:Bar = f() { //~ WARN: irrefutable `if let` pattern + if let Foo:Bar = f() { //~^ ERROR: expected one of //~| HELP: maybe write a path separator here - //~| HELP: consider replacing the `if let` with a `let` } } diff --git a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr index a9bad96f9af..061586882e0 100644 --- a/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr +++ b/tests/ui/parser/issues/issue-87086-colon-path-sep.stderr @@ -64,7 +64,7 @@ LL | if let Foo::Bar = f() { | + error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:49:16 + --> $DIR/issue-87086-colon-path-sep.rs:48:16 | LL | ref qux: Foo::Baz => {} | ^ -------- specifying the type of a pattern isn't supported @@ -77,7 +77,7 @@ LL | ref qux::Foo::Baz => {} | ~~ error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:58:16 + --> $DIR/issue-87086-colon-path-sep.rs:57:16 | LL | mut qux: Foo::Baz => {} | ^ -------- specifying the type of a pattern isn't supported @@ -90,7 +90,7 @@ LL | mut qux::Foo::Baz => {} | ~~ error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:69:12 + --> $DIR/issue-87086-colon-path-sep.rs:68:12 | LL | Foo:Bar::Baz => {} | ^-------- specifying the type of a pattern isn't supported @@ -103,7 +103,7 @@ LL | Foo::Bar::Baz => {} | + error: expected one of `@` or `|`, found `:` - --> $DIR/issue-87086-colon-path-sep.rs:75:12 + --> $DIR/issue-87086-colon-path-sep.rs:74:12 | LL | Foo:Bar => {} | ^--- specifying the type of a pattern isn't supported @@ -115,15 +115,5 @@ help: maybe write a path separator here LL | Foo::Bar => {} | + -warning: irrefutable `if let` pattern - --> $DIR/issue-87086-colon-path-sep.rs:40:8 - | -LL | if let Foo:Bar = f() { - | ^^^^^^^^^^^^^^^^^ - | - = note: this pattern will always match, so the `if let` is useless - = help: consider replacing the `if let` with a `let` - = note: `#[warn(irrefutable_let_patterns)]` on by default - -error: aborting due to 9 previous errors; 1 warning emitted +error: aborting due to 9 previous errors diff --git a/tests/ui/parser/type-ascription-in-pattern.rs b/tests/ui/parser/type-ascription-in-pattern.rs index 18d7061d69c..75059d33db6 100644 --- a/tests/ui/parser/type-ascription-in-pattern.rs +++ b/tests/ui/parser/type-ascription-in-pattern.rs @@ -1,15 +1,16 @@ fn foo(x: bool) -> i32 { - match x { //~ ERROR struct literals are not allowed here - x: i32 => x, //~ ERROR expected - true => 42., //~ ERROR expected identifier - false => 0.333, //~ ERROR expected identifier + match x { + x: i32 => x, //~ ERROR: expected + //~^ ERROR: mismatched types + true => 42., + false => 0.333, } -} //~ ERROR expected one of +} fn main() { match foo(true) { - 42: i32 => (), //~ ERROR expected - _: f64 => (), //~ ERROR expected - x: i32 => (), //~ ERROR expected + 42: i32 => (), //~ ERROR: expected + _: f64 => (), //~ ERROR: expected + x: i32 => (), //~ ERROR: expected } } diff --git a/tests/ui/parser/type-ascription-in-pattern.stderr b/tests/ui/parser/type-ascription-in-pattern.stderr index 135879f208b..09190754993 100644 --- a/tests/ui/parser/type-ascription-in-pattern.stderr +++ b/tests/ui/parser/type-ascription-in-pattern.stderr @@ -1,64 +1,18 @@ -error: expected one of `!`, `,`, `.`, `::`, `?`, `{`, `}`, or an operator, found `=>` - --> $DIR/type-ascription-in-pattern.rs:3:16 - | -LL | match x { - | - while parsing this struct -LL | x: i32 => x, - | -^^ expected one of 8 possible tokens - | | - | help: try adding a comma: `,` - -error: expected identifier, found keyword `true` - --> $DIR/type-ascription-in-pattern.rs:4:9 - | -LL | match x { - | - while parsing this struct -LL | x: i32 => x, -LL | true => 42., - | ^^^^ expected identifier, found keyword - -error: expected identifier, found keyword `false` - --> $DIR/type-ascription-in-pattern.rs:5:9 - | -LL | match x { - | - while parsing this struct -... -LL | false => 0.333, - | ^^^^^ expected identifier, found keyword - -error: struct literals are not allowed here - --> $DIR/type-ascription-in-pattern.rs:2:11 - | -LL | match x { - | ___________^ -LL | | x: i32 => x, -LL | | true => 42., -LL | | false => 0.333, -LL | | } - | |_____^ - | -help: surround the struct literal with parentheses +error: expected one of `@` or `|`, found `:` + --> $DIR/type-ascription-in-pattern.rs:3:10 | -LL ~ match (x { LL | x: i32 => x, -LL | true => 42., -LL | false => 0.333, -LL ~ }) + | ^ --- specifying the type of a pattern isn't supported + | | + | expected one of `@` or `|` | - -error: expected one of `.`, `?`, `{`, or an operator, found `}` - --> $DIR/type-ascription-in-pattern.rs:7:1 +help: maybe write a path separator here | -LL | match x { - | ----- while parsing this `match` expression -... -LL | } - | - expected one of `.`, `?`, `{`, or an operator -LL | } - | ^ unexpected token +LL | x::i32 => x, + | ~~ error: expected one of `...`, `..=`, `..`, or `|`, found `:` - --> $DIR/type-ascription-in-pattern.rs:11:11 + --> $DIR/type-ascription-in-pattern.rs:12:11 | LL | 42: i32 => (), | ^ --- specifying the type of a pattern isn't supported @@ -66,7 +20,7 @@ LL | 42: i32 => (), | expected one of `...`, `..=`, `..`, or `|` error: expected `|`, found `:` - --> $DIR/type-ascription-in-pattern.rs:12:10 + --> $DIR/type-ascription-in-pattern.rs:13:10 | LL | _: f64 => (), | ^ --- specifying the type of a pattern isn't supported @@ -74,7 +28,7 @@ LL | _: f64 => (), | expected `|` error: expected one of `@` or `|`, found `:` - --> $DIR/type-ascription-in-pattern.rs:13:10 + --> $DIR/type-ascription-in-pattern.rs:14:10 | LL | x: i32 => (), | ^ --- specifying the type of a pattern isn't supported @@ -86,5 +40,15 @@ help: maybe write a path separator here LL | x::i32 => (), | ~~ -error: aborting due to 8 previous errors +error[E0308]: mismatched types + --> $DIR/type-ascription-in-pattern.rs:3:19 + | +LL | fn foo(x: bool) -> i32 { + | --- expected `i32` because of return type +LL | match x { +LL | x: i32 => x, + | ^ expected `i32`, found `bool` + +error: aborting due to 5 previous errors +For more information about this error, try `rustc --explain E0308`. |