diff options
Diffstat (limited to 'compiler/rustc_resolve/src/diagnostics.rs')
| -rw-r--r-- | compiler/rustc_resolve/src/diagnostics.rs | 172 |
1 files changed, 164 insertions, 8 deletions
diff --git a/compiler/rustc_resolve/src/diagnostics.rs b/compiler/rustc_resolve/src/diagnostics.rs index 5dfc4292a38..abbacc70b3e 100644 --- a/compiler/rustc_resolve/src/diagnostics.rs +++ b/compiler/rustc_resolve/src/diagnostics.rs @@ -661,8 +661,12 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { ResolutionError::VariableNotBoundInPattern(binding_error, parent_scope) => { let BindingError { name, target, origin, could_be_path } = binding_error; - let target_sp = target.iter().copied().collect::<Vec<_>>(); - let origin_sp = origin.iter().copied().collect::<Vec<_>>(); + let mut target_sp = target.iter().map(|pat| pat.span).collect::<Vec<_>>(); + target_sp.sort(); + target_sp.dedup(); + let mut origin_sp = origin.iter().map(|(span, _)| *span).collect::<Vec<_>>(); + origin_sp.sort(); + origin_sp.dedup(); let msp = MultiSpan::from_spans(target_sp.clone()); let mut err = self @@ -671,8 +675,35 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { for sp in target_sp { err.subdiagnostic(errors::PatternDoesntBindName { span: sp, name }); } - for sp in origin_sp { - err.subdiagnostic(errors::VariableNotInAllPatterns { span: sp }); + for sp in &origin_sp { + err.subdiagnostic(errors::VariableNotInAllPatterns { span: *sp }); + } + let mut suggested_typo = false; + if !target.iter().all(|pat| matches!(pat.kind, ast::PatKind::Ident(..))) + && !origin.iter().all(|(_, pat)| matches!(pat.kind, ast::PatKind::Ident(..))) + { + // The check above is so that when we encounter `match foo { (a | b) => {} }`, + // we don't suggest `(a | a) => {}`, which would never be what the user wants. + let mut target_visitor = BindingVisitor::default(); + for pat in &target { + target_visitor.visit_pat(pat); + } + target_visitor.identifiers.sort(); + target_visitor.identifiers.dedup(); + let mut origin_visitor = BindingVisitor::default(); + for (_, pat) in &origin { + origin_visitor.visit_pat(pat); + } + origin_visitor.identifiers.sort(); + origin_visitor.identifiers.dedup(); + // Find if the binding could have been a typo + if let Some(typo) = + find_best_match_for_name(&target_visitor.identifiers, name.name, None) + && !origin_visitor.identifiers.contains(&typo) + { + err.subdiagnostic(errors::PatternBindingTypo { spans: origin_sp, typo }); + suggested_typo = true; + } } if could_be_path { let import_suggestions = self.lookup_import_candidates( @@ -693,10 +724,86 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { }, ); - if import_suggestions.is_empty() { + if import_suggestions.is_empty() && !suggested_typo { + let kinds = [ + DefKind::Ctor(CtorOf::Variant, CtorKind::Const), + DefKind::Ctor(CtorOf::Struct, CtorKind::Const), + DefKind::Const, + DefKind::AssocConst, + ]; + let mut local_names = vec![]; + self.add_module_candidates( + parent_scope.module, + &mut local_names, + &|res| matches!(res, Res::Def(_, _)), + None, + ); + let local_names: FxHashSet<_> = local_names + .into_iter() + .filter_map(|s| match s.res { + Res::Def(_, def_id) => Some(def_id), + _ => None, + }) + .collect(); + + let mut local_suggestions = vec![]; + let mut suggestions = vec![]; + for kind in kinds { + if let Some(suggestion) = self.early_lookup_typo_candidate( + ScopeSet::All(Namespace::ValueNS), + &parent_scope, + name, + &|res: Res| match res { + Res::Def(k, _) => k == kind, + _ => false, + }, + ) && let Res::Def(kind, mut def_id) = suggestion.res + { + if let DefKind::Ctor(_, _) = kind { + def_id = self.tcx.parent(def_id); + } + let kind = kind.descr(def_id); + if local_names.contains(&def_id) { + // The item is available in the current scope. Very likely to + // be a typo. Don't use the full path. + local_suggestions.push(( + suggestion.candidate, + suggestion.candidate.to_string(), + kind, + )); + } else { + suggestions.push(( + suggestion.candidate, + self.def_path_str(def_id), + kind, + )); + } + } + } + let suggestions = if !local_suggestions.is_empty() { + // There is at least one item available in the current scope that is a + // likely typo. We only show those. + local_suggestions + } else { + suggestions + }; + for (name, sugg, kind) in suggestions { + err.span_suggestion_verbose( + span, + format!( + "you might have meant to use the similarly named {kind} `{name}`", + ), + sugg, + Applicability::MaybeIncorrect, + ); + suggested_typo = true; + } + } + if import_suggestions.is_empty() && !suggested_typo { let help_msg = format!( - "if you meant to match on a variant or a `const` item, consider \ - making the path in the pattern qualified: `path::to::ModOrType::{name}`", + "if you meant to match on a unit struct, unit variant or a `const` \ + item, consider making the path in the pattern qualified: \ + `path::to::ModOrType::{name}`", ); err.span_help(span, help_msg); } @@ -1016,6 +1123,39 @@ impl<'ra, 'tcx> Resolver<'ra, 'tcx> { .emit() } + fn def_path_str(&self, mut def_id: DefId) -> String { + // We can't use `def_path_str` in resolve. + let mut path = vec![def_id]; + while let Some(parent) = self.tcx.opt_parent(def_id) { + def_id = parent; + path.push(def_id); + if def_id.is_top_level_module() { + break; + } + } + // We will only suggest importing directly if it is accessible through that path. + path.into_iter() + .rev() + .map(|def_id| { + self.tcx + .opt_item_name(def_id) + .map(|name| { + match ( + def_id.is_top_level_module(), + def_id.is_local(), + self.tcx.sess.edition(), + ) { + (true, true, Edition::Edition2015) => String::new(), + (true, true, _) => kw::Crate.to_string(), + (true, false, _) | (false, _, _) => name.to_string(), + } + }) + .unwrap_or_else(|| "_".to_string()) + }) + .collect::<Vec<String>>() + .join("::") + } + pub(crate) fn add_scope_set_candidates( &mut self, suggestions: &mut Vec<TypoSuggestion>, @@ -3396,7 +3536,7 @@ impl UsePlacementFinder { } } -impl<'tcx> visit::Visitor<'tcx> for UsePlacementFinder { +impl<'tcx> Visitor<'tcx> for UsePlacementFinder { fn visit_crate(&mut self, c: &Crate) { if self.target_module == CRATE_NODE_ID { let inject = c.spans.inject_use_span; @@ -3424,6 +3564,22 @@ impl<'tcx> visit::Visitor<'tcx> for UsePlacementFinder { } } +#[derive(Default)] +struct BindingVisitor { + identifiers: Vec<Symbol>, + spans: FxHashMap<Symbol, Vec<Span>>, +} + +impl<'tcx> Visitor<'tcx> for BindingVisitor { + fn visit_pat(&mut self, pat: &ast::Pat) { + if let ast::PatKind::Ident(_, ident, _) = pat.kind { + self.identifiers.push(ident.name); + self.spans.entry(ident.name).or_default().push(ident.span); + } + visit::walk_pat(self, pat); + } +} + fn search_for_any_use_in_items(items: &[Box<ast::Item>]) -> Option<Span> { for item in items { if let ItemKind::Use(..) = item.kind |