diff options
| -rw-r--r-- | compiler/rustc_resolve/src/late/diagnostics.rs | 434 |
1 files changed, 261 insertions, 173 deletions
diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs index c3c9b0b5617..ac115360257 100644 --- a/compiler/rustc_resolve/src/late/diagnostics.rs +++ b/compiler/rustc_resolve/src/late/diagnostics.rs @@ -130,6 +130,15 @@ pub(super) enum LifetimeElisionCandidate { Missing(MissingLifetime), } +struct BaseError<'a> { + msg: String, + fallback_label: String, + span: Span, + span_label: Option<(Span, &'a str)>, + could_be_expr: bool, + suggestion: Option<(Span, &'a str, String)>, +} + impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { fn def_span(&self, def_id: DefId) -> Option<Span> { match def_id.krate { @@ -138,35 +147,18 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } - /// Handles error reporting for `smart_resolve_path_fragment` function. - /// Creates base error and amends it with one short label and possibly some longer helps/notes. - pub(crate) fn smart_resolve_report_errors( + fn make_base_error( &mut self, path: &[Segment], span: Span, source: PathSource<'_>, res: Option<Res>, - ) -> (DiagnosticBuilder<'a, ErrorGuaranteed>, Vec<ImportSuggestion>) { - let ident_span = path.last().map_or(span, |ident| ident.ident.span); - let ns = source.namespace(); - let is_expected = &|res| source.is_expected(res); - let is_enum_variant = &|res| matches!(res, Res::Def(DefKind::Variant, _)); - - debug!(?res, ?source); - + ) -> BaseError<'static> { // Make the base error. - struct BaseError<'a> { - msg: String, - fallback_label: String, - span: Span, - span_label: Option<(Span, &'a str)>, - could_be_expr: bool, - suggestion: Option<(Span, &'a str, String)>, - } let mut expected = source.descr_expected(); let path_str = Segment::names_to_string(path); let item_str = path.last().unwrap().ident; - let base_error = if let Some(res) = res { + if let Some(res) = res { BaseError { msg: format!("expected {}, found {} `{}`", expected, res.descr(), path_str), fallback_label: format!("not a {expected}"), @@ -277,53 +269,92 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { could_be_expr: false, suggestion, } - }; + } + } + /// Handles error reporting for `smart_resolve_path_fragment` function. + /// Creates base error and amends it with one short label and possibly some longer helps/notes. + pub(crate) fn smart_resolve_report_errors( + &mut self, + path: &[Segment], + span: Span, + source: PathSource<'_>, + res: Option<Res>, + ) -> (DiagnosticBuilder<'a, ErrorGuaranteed>, Vec<ImportSuggestion>) { + debug!(?res, ?source); + let base_error = self.make_base_error(path, span, source, res); let code = source.error_code(res.is_some()); let mut err = self.r.session.struct_span_err_with_code(base_error.span, &base_error.msg, code); self.suggest_swapping_misplaced_self_ty_and_trait(&mut err, source, res, base_error.span); - if let Some((span, label)) = base_error.span_label { + if let Some((span, label)) = base_error.span_label.clone() { err.span_label(span, label); } - if let Some(sugg) = base_error.suggestion { - err.span_suggestion_verbose(sugg.0, sugg.1, sugg.2, Applicability::MaybeIncorrect); + if let Some(ref sugg) = base_error.suggestion { + err.span_suggestion_verbose(sugg.0, sugg.1, &sugg.2, Applicability::MaybeIncorrect); } - if let Some(span) = self.diagnostic_metadata.current_block_could_be_bare_struct_literal { - err.multipart_suggestion( - "you might have meant to write a `struct` literal", - vec![ - (span.shrink_to_lo(), "{ SomeStruct ".to_string()), - (span.shrink_to_hi(), "}".to_string()), - ], - Applicability::HasPlaceholders, - ); + self.suggest_bare_struct_literal(&mut err); + self.suggest_pattern_match_with_let(&mut err, source, span); + + self.suggest_self_or_self_ref(&mut err, path, span); + self.detect_assoct_type_constraint_meant_as_path(&mut err, &base_error); + if self.suggest_self_ty_or_self_value(&mut err, source, path, span) { + return (err, Vec::new()); } - match (source, self.diagnostic_metadata.in_if_condition) { - ( - PathSource::Expr(_), - Some(Expr { span: expr_span, kind: ExprKind::Assign(lhs, _, _), .. }), - ) => { - // Icky heuristic so we don't suggest: - // `if (i + 2) = 2` => `if let (i + 2) = 2` (approximately pattern) - // `if 2 = i` => `if let 2 = i` (lhs needs to contain error span) - if lhs.is_approximately_pattern() && lhs.span.contains(span) { - err.span_suggestion_verbose( - expr_span.shrink_to_lo(), - "you might have meant to use pattern matching", - "let ", - Applicability::MaybeIncorrect, - ); + + let (found, candidates) = + self.try_lookup_name_with_relex_fashion(&mut err, source, path, span, res, &base_error); + if found { + return (err, candidates); + } + + self.suggest_type_ascription(&mut err, source, path, res, span, &base_error); + self.add_err_code_cases(&mut err, source, path, span); + + (err, candidates) + } + + fn detect_assoct_type_constraint_meant_as_path( + &self, + err: &mut Diagnostic, + base_error: &BaseError<'static>, + ) { + let Some(ty) = self.diagnostic_metadata.current_type_path else { return; }; + let TyKind::Path(_, path) = &ty.kind else { return; }; + for segment in &path.segments { + let Some(params) = &segment.args else { continue; }; + let ast::GenericArgs::AngleBracketed(ref params) = params.deref() else { continue; }; + for param in ¶ms.args { + let ast::AngleBracketedArg::Constraint(constraint) = param else { continue; }; + let ast::AssocConstraintKind::Bound { bounds } = &constraint.kind else { + continue; + }; + for bound in bounds { + let ast::GenericBound::Trait(trait_ref, ast::TraitBoundModifier::None) + = bound else + { + continue; + }; + if base_error.span == trait_ref.span { + err.span_suggestion_verbose( + constraint.ident.span.between(trait_ref.span), + "you might have meant to write a path instead of an associated type bound", + "::", + Applicability::MachineApplicable, + ); + } } } - _ => {} } + } + fn suggest_self_or_self_ref(&mut self, err: &mut Diagnostic, path: &[Segment], span: Span) { let is_assoc_fn = self.self_type_is_available(); + let item_str = path.last().unwrap().ident; // Emit help message for fake-self from other languages (e.g., `this` in Javascript). if ["this", "my"].contains(&item_str.as_str()) && is_assoc_fn { err.span_suggestion_short( @@ -358,96 +389,25 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } } + } - self.detect_assoct_type_constraint_meant_as_path(base_error.span, &mut err); - - // Emit special messages for unresolved `Self` and `self`. - if is_self_type(path, ns) { - err.code(rustc_errors::error_code!(E0411)); - err.span_label( - span, - "`Self` is only available in impls, traits, and type definitions".to_string(), - ); - if let Some(item_kind) = self.diagnostic_metadata.current_item { - err.span_label( - item_kind.ident.span, - format!( - "`Self` not allowed in {} {}", - item_kind.kind.article(), - item_kind.kind.descr() - ), - ); - } - return (err, Vec::new()); - } - if is_self_value(path, ns) { - debug!("smart_resolve_path_fragment: E0424, source={:?}", source); - - err.code(rustc_errors::error_code!(E0424)); - err.span_label(span, match source { - PathSource::Pat => "`self` value is a keyword and may not be bound to variables or shadowed", - _ => "`self` value is a keyword only available in methods with a `self` parameter", - }); - if let Some((fn_kind, span)) = &self.diagnostic_metadata.current_function { - // The current function has a `self' parameter, but we were unable to resolve - // a reference to `self`. This can only happen if the `self` identifier we - // are resolving came from a different hygiene context. - if fn_kind.decl().inputs.get(0).map_or(false, |p| p.is_self()) { - err.span_label(*span, "this function has a `self` parameter, but a macro invocation can only access identifiers it receives from parameters"); - } else { - let doesnt = if is_assoc_fn { - let (span, sugg) = fn_kind - .decl() - .inputs - .get(0) - .map(|p| (p.span.shrink_to_lo(), "&self, ")) - .unwrap_or_else(|| { - // Try to look for the "(" after the function name, if possible. - // This avoids placing the suggestion into the visibility specifier. - let span = fn_kind - .ident() - .map_or(*span, |ident| span.with_lo(ident.span.hi())); - ( - self.r - .session - .source_map() - .span_through_char(span, '(') - .shrink_to_hi(), - "&self", - ) - }); - err.span_suggestion_verbose( - span, - "add a `self` receiver parameter to make the associated `fn` a method", - sugg, - Applicability::MaybeIncorrect, - ); - "doesn't" - } else { - "can't" - }; - if let Some(ident) = fn_kind.ident() { - err.span_label( - ident.span, - &format!("this function {} have a `self` parameter", doesnt), - ); - } - } - } else if let Some(item_kind) = self.diagnostic_metadata.current_item { - err.span_label( - item_kind.ident.span, - format!( - "`self` not allowed in {} {}", - item_kind.kind.article(), - item_kind.kind.descr() - ), - ); - } - return (err, Vec::new()); - } - + fn try_lookup_name_with_relex_fashion( + &mut self, + err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>, + source: PathSource<'_>, + path: &[Segment], + span: Span, + res: Option<Res>, + base_error: &BaseError<'static>, + ) -> (bool, Vec<ImportSuggestion>) { // Try to lookup name in more relaxed fashion for better error reporting. let ident = path.last().unwrap().ident; + let is_expected = &|res| source.is_expected(res); + let ns = source.namespace(); + let is_enum_variant = &|res| matches!(res, Res::Def(DefKind::Variant, _)); + let path_str = Segment::names_to_string(path); + let ident_span = path.last().map_or(span, |ident| ident.ident.span); + let mut candidates = self .r .lookup_import_candidates(ident, ns, &self.parent_scope, is_expected) @@ -494,7 +454,7 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { { // Already reported this issue on the lhs of the type ascription. err.delay_as_bug(); - return (err, candidates); + return (true, candidates); } } @@ -522,8 +482,9 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { ); } } + // Try Levenshtein algorithm. - let typo_sugg = self.lookup_typo_candidate(path, ns, is_expected); + let typo_sugg = self.lookup_typo_candidate(path, source.namespace(), is_expected); if path.len() == 1 && self.self_type_is_available() { if let Some(candidate) = self.lookup_assoc_candidate(ident, ns, is_expected) { let self_is_available = self.self_value_is_available(path[0].ident.span); @@ -560,8 +521,8 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { ); } } - self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span); - return (err, candidates); + self.r.add_typo_suggestion(err, typo_sugg, ident_span); + return (true, candidates); } // If the first argument in call is `self` suggest calling a method. @@ -579,14 +540,14 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { format!("self.{path_str}({args_snippet})"), Applicability::MachineApplicable, ); - return (err, candidates); + return (true, candidates); } } // Try context-dependent help if relaxed lookup didn't work. if let Some(res) = res { if self.smart_resolve_context_dependent_help( - &mut err, + err, span, source, res, @@ -594,14 +555,25 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { &base_error.fallback_label, ) { // We do this to avoid losing a secondary span when we override the main error span. - self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span); - return (err, candidates); + self.r.add_typo_suggestion(err, typo_sugg, ident_span); + return (true, candidates); } } + return (false, candidates); + } + fn suggest_type_ascription( + &mut self, + err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>, + source: PathSource<'_>, + path: &[Segment], + res: Option<Res>, + span: Span, + base_error: &BaseError<'static>, + ) { let is_macro = base_error.span.from_expansion() && base_error.span.desugaring_kind().is_none(); - if !self.type_ascription_suggestion(&mut err, base_error.span) { + if !self.type_ascription_suggestion(err, base_error.span) { let mut fallback = false; if let ( PathSource::Trait(AliasPossibility::Maybe), @@ -663,9 +635,12 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } - fallback |= self.restrict_assoc_type_in_where_clause(span, &mut err); + let is_expected = &|res| source.is_expected(res); + let ident_span = path.last().map_or(span, |ident| ident.ident.span); + fallback |= self.restrict_assoc_type_in_where_clause(span, err); - if !self.r.add_typo_suggestion(&mut err, typo_sugg, ident_span) { + let typo_sugg = self.lookup_typo_candidate(path, source.namespace(), is_expected); + if !self.r.add_typo_suggestion(err, typo_sugg, ident_span) { fallback = true; match self.diagnostic_metadata.current_let_binding { Some((pat_sp, Some(ty_sp), None)) @@ -683,17 +658,27 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { // If the trait has a single item (which wasn't matched by Levenshtein), suggest it let suggestion = self.get_single_associated_item(&path, &source, is_expected); - self.r.add_typo_suggestion(&mut err, suggestion, ident_span); + self.r.add_typo_suggestion(err, suggestion, ident_span); } if fallback { // Fallback label. - err.span_label(base_error.span, base_error.fallback_label); + err.span_label(base_error.span, &base_error.fallback_label); } } + } + + fn add_err_code_cases( + &mut self, + err: &mut DiagnosticBuilder<'_, ErrorGuaranteed>, + source: PathSource<'_>, + path: &[Segment], + span: Span, + ) { if let Some(err_code) = &err.code { if err_code == &rustc_errors::error_code!(E0425) { for label_rib in &self.label_ribs { for (label_ident, node_id) in &label_rib.bindings { + let ident = path.last().unwrap().ident; if format!("'{}", ident) == label_ident.to_string() { err.span_label(label_ident.span, "a label with a similar name exists"); if let PathSource::Expr(Some(Expr { @@ -724,38 +709,106 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } } - - (err, candidates) } - fn detect_assoct_type_constraint_meant_as_path(&self, base_span: Span, err: &mut Diagnostic) { - let Some(ty) = self.diagnostic_metadata.current_type_path else { return; }; - let TyKind::Path(_, path) = &ty.kind else { return; }; - for segment in &path.segments { - let Some(params) = &segment.args else { continue; }; - let ast::GenericArgs::AngleBracketed(ref params) = params.deref() else { continue; }; - for param in ¶ms.args { - let ast::AngleBracketedArg::Constraint(constraint) = param else { continue; }; - let ast::AssocConstraintKind::Bound { bounds } = &constraint.kind else { - continue; - }; - for bound in bounds { - let ast::GenericBound::Trait(trait_ref, ast::TraitBoundModifier::None) - = bound else - { - continue; - }; - if base_span == trait_ref.span { + /// Emit special messages for unresolved `Self` and `self`. + fn suggest_self_ty_or_self_value( + &mut self, + err: &mut Diagnostic, + source: PathSource<'_>, + path: &[Segment], + span: Span, + ) -> bool { + if is_self_type(path, source.namespace()) { + err.code(rustc_errors::error_code!(E0411)); + err.span_label( + span, + "`Self` is only available in impls, traits, and type definitions".to_string(), + ); + if let Some(item_kind) = self.diagnostic_metadata.current_item { + err.span_label( + item_kind.ident.span, + format!( + "`Self` not allowed in {} {}", + item_kind.kind.article(), + item_kind.kind.descr() + ), + ); + } + return true; + } + + if is_self_value(path, source.namespace()) { + debug!("smart_resolve_path_fragment: E0424, source={:?}", source); + err.code(rustc_errors::error_code!(E0424)); + err.span_label( + span, + match source { + PathSource::Pat => { + "`self` value is a keyword and may not be bound to variables or shadowed" + } + _ => "`self` value is a keyword only available in methods with a `self` parameter", + }, + ); + let is_assoc_fn = self.self_type_is_available(); + if let Some((fn_kind, span)) = &self.diagnostic_metadata.current_function { + // The current function has a `self' parameter, but we were unable to resolve + // a reference to `self`. This can only happen if the `self` identifier we + // are resolving came from a different hygiene context. + if fn_kind.decl().inputs.get(0).map_or(false, |p| p.is_self()) { + err.span_label(*span, "this function has a `self` parameter, but a macro invocation can only access identifiers it receives from parameters"); + } else { + let doesnt = if is_assoc_fn { + let (span, sugg) = fn_kind + .decl() + .inputs + .get(0) + .map(|p| (p.span.shrink_to_lo(), "&self, ")) + .unwrap_or_else(|| { + // Try to look for the "(" after the function name, if possible. + // This avoids placing the suggestion into the visibility specifier. + let span = fn_kind + .ident() + .map_or(*span, |ident| span.with_lo(ident.span.hi())); + ( + self.r + .session + .source_map() + .span_through_char(span, '(') + .shrink_to_hi(), + "&self", + ) + }); err.span_suggestion_verbose( - constraint.ident.span.between(trait_ref.span), - "you might have meant to write a path instead of an associated type bound", - "::", - Applicability::MachineApplicable, + span, + "add a `self` receiver parameter to make the associated `fn` a method", + sugg, + Applicability::MaybeIncorrect, + ); + "doesn't" + } else { + "can't" + }; + if let Some(ident) = fn_kind.ident() { + err.span_label( + ident.span, + &format!("this function {} have a `self` parameter", doesnt), ); } } + } else if let Some(item_kind) = self.diagnostic_metadata.current_item { + err.span_label( + item_kind.ident.span, + format!( + "`self` not allowed in {} {}", + item_kind.kind.article(), + item_kind.kind.descr() + ), + ); } + return true; } + false } fn suggest_swapping_misplaced_self_ty_and_trait( @@ -787,6 +840,41 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> { } } + fn suggest_bare_struct_literal(&mut self, err: &mut Diagnostic) { + if let Some(span) = self.diagnostic_metadata.current_block_could_be_bare_struct_literal { + err.multipart_suggestion( + "you might have meant to write a `struct` literal", + vec![ + (span.shrink_to_lo(), "{ SomeStruct ".to_string()), + (span.shrink_to_hi(), "}".to_string()), + ], + Applicability::HasPlaceholders, + ); + } + } + + fn suggest_pattern_match_with_let( + &mut self, + err: &mut Diagnostic, + source: PathSource<'_>, + span: Span, + ) { + if let PathSource::Expr(_) = source && + let Some(Expr { span: expr_span, kind: ExprKind::Assign(lhs, _, _), .. } ) = self.diagnostic_metadata.in_if_condition { + // Icky heuristic so we don't suggest: + // `if (i + 2) = 2` => `if let (i + 2) = 2` (approximately pattern) + // `if 2 = i` => `if let 2 = i` (lhs needs to contain error span) + if lhs.is_approximately_pattern() && lhs.span.contains(span) { + err.span_suggestion_verbose( + expr_span.shrink_to_lo(), + "you might have meant to use pattern matching", + "let ", + Applicability::MaybeIncorrect, + ); + } + } + } + fn get_single_associated_item( &mut self, path: &[Segment], |