diff options
Diffstat (limited to 'compiler/rustc_parse/src/parser/diagnostics.rs')
| -rw-r--r-- | compiler/rustc_parse/src/parser/diagnostics.rs | 29 |
1 files changed, 23 insertions, 6 deletions
diff --git a/compiler/rustc_parse/src/parser/diagnostics.rs b/compiler/rustc_parse/src/parser/diagnostics.rs index 716ababb008..c1cca1186af 100644 --- a/compiler/rustc_parse/src/parser/diagnostics.rs +++ b/compiler/rustc_parse/src/parser/diagnostics.rs @@ -2874,7 +2874,12 @@ impl<'a> Parser<'a> { first_pat } - pub(crate) fn maybe_recover_unexpected_block_label(&mut self) -> bool { + /// If `loop_header` is `Some` and an unexpected block label is encountered, + /// it is suggested to be moved just before `loop_header`, else it is suggested to be removed. + pub(crate) fn maybe_recover_unexpected_block_label( + &mut self, + loop_header: Option<Span>, + ) -> bool { // Check for `'a : {` if !(self.check_lifetime() && self.look_ahead(1, |t| *t == token::Colon) @@ -2885,16 +2890,28 @@ impl<'a> Parser<'a> { let label = self.eat_label().expect("just checked if a label exists"); self.bump(); // eat `:` let span = label.ident.span.to(self.prev_token.span); - self.dcx() + let mut diag = self + .dcx() .struct_span_err(span, "block label not supported here") - .with_span_label(span, "not supported here") - .with_tool_only_span_suggestion( + .with_span_label(span, "not supported here"); + if let Some(loop_header) = loop_header { + diag.multipart_suggestion( + "if you meant to label the loop, move this label before the loop", + vec![ + (label.ident.span.until(self.token.span), String::from("")), + (loop_header.shrink_to_lo(), format!("{}: ", label.ident)), + ], + Applicability::MachineApplicable, + ); + } else { + diag.tool_only_span_suggestion( label.ident.span.until(self.token.span), "remove this block label", "", Applicability::MachineApplicable, - ) - .emit(); + ); + } + diag.emit(); true } |