diff --git a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs index b7d3617fbe73..0ec73a194754 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs @@ -2,10 +2,12 @@ use rustc_ast::TraitObjectSyntax; use rustc_errors::codes::*; use rustc_errors::{Diag, EmissionGuarantee, ErrorGuaranteed, StashKey, Suggestions}; use rustc_hir as hir; -use rustc_hir::def::{DefKind, Res}; +use rustc_hir::def::{DefKind, Namespace, Res}; +use rustc_hir::def_id::DefId; use rustc_lint_defs::Applicability; use rustc_lint_defs::builtin::BARE_TRAIT_OBJECTS; use rustc_span::Span; +use rustc_span::edit_distance::find_best_match_for_name; use rustc_trait_selection::error_reporting::traits::suggestions::NextTypeParamName; use super::HirTyLowerer; @@ -86,7 +88,12 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { // Check if the impl trait that we are considering is an impl of a local trait. self.maybe_suggest_blanket_trait_impl(self_ty, &mut diag); self.maybe_suggest_assoc_ty_bound(self_ty, &mut diag); - // In case there is an associate type with the same name + self.maybe_suggest_typoed_method( + self_ty, + poly_trait_ref.trait_ref.trait_def_id(), + &mut diag, + ); + // In case there is an associated type with the same name // Add the suggestion to this error if let Some(mut sugg) = tcx.dcx().steal_non_err(self_ty.span, StashKey::AssociatedTypeSuggestion) @@ -343,4 +350,44 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { ); } } + + fn maybe_suggest_typoed_method( + &self, + self_ty: &hir::Ty<'_>, + trait_def_id: Option, + diag: &mut Diag<'_>, + ) { + let tcx = self.tcx(); + let Some(trait_def_id) = trait_def_id else { + return; + }; + let hir::Node::Expr(hir::Expr { + kind: hir::ExprKind::Path(hir::QPath::TypeRelative(path_ty, segment)), + .. + }) = tcx.parent_hir_node(self_ty.hir_id) + else { + return; + }; + if path_ty.hir_id != self_ty.hir_id { + return; + } + let names: Vec<_> = tcx + .associated_items(trait_def_id) + .in_definition_order() + .filter(|assoc| assoc.kind.namespace() == Namespace::ValueNS) + .map(|cand| cand.name) + .collect(); + if let Some(typo) = find_best_match_for_name(&names, segment.ident.name, None) { + diag.span_suggestion_verbose( + segment.ident.span, + format!( + "you may have misspelled this associated item, causing `{}` \ + to be interpreted as a type rather than a trait", + tcx.item_name(trait_def_id), + ), + typo, + Applicability::MaybeIncorrect, + ); + } + } } diff --git a/tests/ui/dyn-keyword/misspelled-associated-item.rs b/tests/ui/dyn-keyword/misspelled-associated-item.rs new file mode 100644 index 000000000000..8319e797d621 --- /dev/null +++ b/tests/ui/dyn-keyword/misspelled-associated-item.rs @@ -0,0 +1,12 @@ +//@ edition: 2021 + +trait Trait { + fn typo() -> Self; +} + +fn main() { + let () = Trait::typoe(); + //~^ ERROR expected a type, found a trait + //~| HELP you can add the `dyn` keyword if you want a trait object + //~| HELP you may have misspelled this associated item +} diff --git a/tests/ui/dyn-keyword/misspelled-associated-item.stderr b/tests/ui/dyn-keyword/misspelled-associated-item.stderr new file mode 100644 index 000000000000..4211889e524c --- /dev/null +++ b/tests/ui/dyn-keyword/misspelled-associated-item.stderr @@ -0,0 +1,18 @@ +error[E0782]: expected a type, found a trait + --> $DIR/misspelled-associated-item.rs:8:14 + | +LL | let () = Trait::typoe(); + | ^^^^^ + | +help: you can add the `dyn` keyword if you want a trait object + | +LL | let () = ::typoe(); + | ++++ + +help: you may have misspelled this associated item, causing `Trait` to be interpreted as a type rather than a trait + | +LL | let () = Trait::typo(); + | ~~~~ + +error: aborting due to 1 previous error + +For more information about this error, try `rustc --explain E0782`.