diff options
Diffstat (limited to 'compiler/rustc_mir_build/src/thir/pattern/mod.rs')
| -rw-r--r-- | compiler/rustc_mir_build/src/thir/pattern/mod.rs | 123 |
1 files changed, 88 insertions, 35 deletions
diff --git a/compiler/rustc_mir_build/src/thir/pattern/mod.rs b/compiler/rustc_mir_build/src/thir/pattern/mod.rs index a35c880120b..9e1451f4caa 100644 --- a/compiler/rustc_mir_build/src/thir/pattern/mod.rs +++ b/compiler/rustc_mir_build/src/thir/pattern/mod.rs @@ -53,16 +53,29 @@ pub(super) fn pat_from_hir<'a, 'tcx>( suggestion: Vec::new(), ref_pattern_count: 0, binding_mode_count: 0, + default_mode_span: None, + default_mode_labels: Default::default(), })), }; let result = pcx.lower_pattern(pat); debug!("pat_from_hir({:?}) = {:?}", pat, result); if let Some(info) = migration_info { let sugg = pcx.rust_2024_migration_suggestion.expect("suggestion should be present"); - let mut spans = MultiSpan::from_spans(info.primary_spans.clone()); - for (span, label) in &info.span_labels { + let mut spans = + MultiSpan::from_spans(info.primary_labels.iter().map(|(span, _)| *span).collect()); + for (span, label) in &info.primary_labels { spans.push_span_label(*span, label.clone()); } + for (span, label_mutbl) in &sugg.default_mode_labels { + // Don't point to a macro call site. + if !span.from_expansion() { + let label = match label_mutbl { + Mutability::Not => "default binding mode is `ref`", + Mutability::Mut => "default binding mode is `ref mut`", + }; + spans.push_span_label(*span, label.to_owned()) + } + } // If a relevant span is from at least edition 2024, this is a hard error. let is_hard_error = spans.primary_spans().iter().any(|span| span.at_least_rust_2024()); if is_hard_error { @@ -96,6 +109,40 @@ pub(super) fn pat_from_hir<'a, 'tcx>( impl<'a, 'tcx> PatCtxt<'a, 'tcx> { fn lower_pattern(&mut self, pat: &'tcx hir::Pat<'tcx>) -> Box<Pat<'tcx>> { + let adjustments: &[Ty<'tcx>] = + self.typeck_results.pat_adjustments().get(pat.hir_id).map_or(&[], |v| &**v); + + let mut opt_old_mode_span = None; + if let Some(s) = &mut self.rust_2024_migration_suggestion + && !adjustments.is_empty() + { + let mut min_mutbl = Mutability::Mut; + let suggestion_str: String = adjustments + .iter() + .map(|ref_ty| { + let &ty::Ref(_, _, mutbl) = ref_ty.kind() else { + span_bug!(pat.span, "pattern implicitly dereferences a non-ref type"); + }; + + match mutbl { + Mutability::Not => { + min_mutbl = Mutability::Not; + "&" + } + Mutability::Mut => "&mut ", + } + }) + .collect(); + s.suggestion.push((pat.span.shrink_to_lo(), suggestion_str)); + s.ref_pattern_count += adjustments.len(); + + // Remember if this changed the default binding mode, in case we want to label it. + if s.default_mode_span.is_none_or(|(_, old_mutbl)| min_mutbl < old_mutbl) { + opt_old_mode_span = Some(s.default_mode_span); + s.default_mode_span = Some((pat.span, min_mutbl)); + } + }; + // When implicit dereferences have been inserted in this pattern, the unadjusted lowered // pattern has the type that results *after* dereferencing. For example, in this code: // @@ -124,8 +171,6 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { _ => self.lower_pattern_unadjusted(pat), }; - let adjustments: &[Ty<'tcx>] = - self.typeck_results.pat_adjustments().get(pat.hir_id).map_or(&[], |v| &**v); let adjusted_pat = adjustments.iter().rev().fold(unadjusted_pat, |thir_pat, ref_ty| { debug!("{:?}: wrapping pattern with type {:?}", thir_pat, ref_ty); Box::new(Pat { @@ -136,24 +181,10 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { }); if let Some(s) = &mut self.rust_2024_migration_suggestion - && !adjustments.is_empty() + && let Some(old_mode_span) = opt_old_mode_span { - let suggestion_str: String = adjustments - .iter() - .map(|ref_ty| { - let &ty::Ref(_, _, mutbl) = ref_ty.kind() else { - span_bug!(pat.span, "pattern implicitly dereferences a non-ref type"); - }; - - match mutbl { - ty::Mutability::Not => "&", - ty::Mutability::Mut => "&mut ", - } - }) - .collect(); - s.suggestion.push((pat.span.shrink_to_lo(), suggestion_str)); - s.ref_pattern_count += adjustments.len(); - }; + s.default_mode_span = old_mode_span; + } adjusted_pat } @@ -353,7 +384,22 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { let mutability = if mutable { hir::Mutability::Mut } else { hir::Mutability::Not }; PatKind::DerefPattern { subpattern: self.lower_pattern(subpattern), mutability } } - hir::PatKind::Ref(subpattern, _) | hir::PatKind::Box(subpattern) => { + hir::PatKind::Ref(subpattern, _) => { + // Track the default binding mode for the Rust 2024 migration suggestion. + let old_mode_span = self.rust_2024_migration_suggestion.as_mut().and_then(|s| { + if let Some((default_mode_span, default_ref_mutbl)) = s.default_mode_span { + // If this eats a by-ref default binding mode, label the binding mode. + s.default_mode_labels.insert(default_mode_span, default_ref_mutbl); + } + s.default_mode_span.take() + }); + let subpattern = self.lower_pattern(subpattern); + if let Some(s) = &mut self.rust_2024_migration_suggestion { + s.default_mode_span = old_mode_span; + } + PatKind::Deref { subpattern } + } + hir::PatKind::Box(subpattern) => { PatKind::Deref { subpattern: self.lower_pattern(subpattern) } } @@ -380,19 +426,26 @@ impl<'a, 'tcx> PatCtxt<'a, 'tcx> { .get(pat.hir_id) .expect("missing binding mode"); - if let Some(s) = &mut self.rust_2024_migration_suggestion - && explicit_ba.0 == ByRef::No - && let ByRef::Yes(mutbl) = mode.0 - { - let sugg_str = match mutbl { - Mutability::Not => "ref ", - Mutability::Mut => "ref mut ", - }; - s.suggestion.push(( - pat.span.with_lo(ident.span.lo()).shrink_to_lo(), - sugg_str.to_owned(), - )); - s.binding_mode_count += 1; + if let Some(s) = &mut self.rust_2024_migration_suggestion { + if explicit_ba != hir::BindingMode::NONE + && let Some((default_mode_span, default_ref_mutbl)) = s.default_mode_span + { + // If this overrides a by-ref default binding mode, label the binding mode. + s.default_mode_labels.insert(default_mode_span, default_ref_mutbl); + } + if explicit_ba.0 == ByRef::No + && let ByRef::Yes(mutbl) = mode.0 + { + let sugg_str = match mutbl { + Mutability::Not => "ref ", + Mutability::Mut => "ref mut ", + }; + s.suggestion.push(( + pat.span.with_lo(ident.span.lo()).shrink_to_lo(), + sugg_str.to_owned(), + )); + s.binding_mode_count += 1; + } } // A ref x pattern is the same node used for x, and as such it has |