diff options
Diffstat (limited to 'compiler/rustc_parse')
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 74 | ||||
| -rw-r--r-- | compiler/rustc_parse/src/parser/expr.rs | 58 |
2 files changed, 74 insertions, 58 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index a28af7833c3..8b87e4d9690 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(); @@ -2947,26 +2939,24 @@ impl<'a> Parser<'a> { } let seq_span = lo.to(self.prev_token.span); let mut err = self.dcx().struct_span_err(comma_span, "unexpected `,` in pattern"); - if let Ok(seq_snippet) = self.span_to_snippet(seq_span) { - err.multipart_suggestion( - format!( - "try adding parentheses to match on a tuple{}", - if let CommaRecoveryMode::LikelyTuple = rt { "" } else { "..." }, - ), - vec![ - (seq_span.shrink_to_lo(), "(".to_string()), - (seq_span.shrink_to_hi(), ")".to_string()), - ], + err.multipart_suggestion( + format!( + "try adding parentheses to match on a tuple{}", + if let CommaRecoveryMode::LikelyTuple = rt { "" } else { "..." }, + ), + vec![ + (seq_span.shrink_to_lo(), "(".to_string()), + (seq_span.shrink_to_hi(), ")".to_string()), + ], + Applicability::MachineApplicable, + ); + if let CommaRecoveryMode::EitherTupleOrPipe = rt { + err.span_suggestion( + comma_span, + "...or a vertical bar to match on alternatives", + " |", Applicability::MachineApplicable, ); - if let CommaRecoveryMode::EitherTupleOrPipe = rt { - err.span_suggestion( - seq_span, - "...or a vertical bar to match on multiple alternatives", - seq_snippet.replace(',', " |"), - Applicability::MachineApplicable, - ); - } } Err(err) } 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( |