diff --git a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs index a9a92fdbd64..465358de932 100644 --- a/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs +++ b/compiler/rustc_infer/src/infer/error_reporting/need_type_info.rs @@ -734,22 +734,28 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> { if !impl_candidates.is_empty() && e.span.contains(span) && let Some(expr) = exprs.first() && let ExprKind::Path(hir::QPath::Resolved(_, path)) = expr.kind - && let [path_segment] = path.segments + && let [_] = path.segments { + let mut eraser = TypeParamEraser(self.tcx); let candidate_len = impl_candidates.len(); - let suggestions = impl_candidates.iter().map(|candidate| { - format!( - "{}::{}({})", - candidate, segment.ident, path_segment.ident - ) - }); - err.span_suggestions( - e.span, + let mut suggestions: Vec<_> = impl_candidates.iter().map(|candidate| { + let candidate = candidate.super_fold_with(&mut eraser); + vec![ + (expr.span.shrink_to_lo(), format!("{}::{}(", candidate, segment.ident)), + if exprs.len() == 1 { + (expr.span.shrink_to_hi().with_hi(e.span.hi()), ")".to_string()) + } else { + (expr.span.shrink_to_hi().with_hi(exprs[1].span.lo()), ", ".to_string()) + }, + ] + }).collect(); + suggestions.sort_by(|a, b| a[0].1.cmp(&b[0].1)); + err.multipart_suggestions( &format!( "use the fully qualified path for the potential candidate{}", pluralize!(candidate_len), ), - suggestions, + suggestions.into_iter(), Applicability::MaybeIncorrect, ); } @@ -1037,3 +1043,18 @@ impl<'tcx> TypeFolder<'tcx> for ErrTypeParamEraser<'tcx> { } } } + +/// Replace type parameters with `ty::Infer(ty::Var)` to display `_`. +struct TypeParamEraser<'tcx>(TyCtxt<'tcx>); + +impl<'tcx> TypeFolder<'tcx> for TypeParamEraser<'tcx> { + fn tcx<'a>(&'a self) -> TyCtxt<'tcx> { + self.0 + } + fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> { + match t.kind() { + ty::Param(_) | ty::Error(_) => self.tcx().mk_ty_var(ty::TyVid::from_u32(0)), + _ => t.super_fold_with(self), + } + } +} diff --git a/src/test/ui/error-codes/E0283.stderr b/src/test/ui/error-codes/E0283.stderr index 7dcfe96b35c..e2bab486064 100644 --- a/src/test/ui/error-codes/E0283.stderr +++ b/src/test/ui/error-codes/E0283.stderr @@ -14,7 +14,6 @@ LL | let bar = foo_impl.into() * 1u32; | | | | | cannot infer type for type parameter `T` declared on the trait `Into` | this method call resolves to `T` - | help: use the fully qualified path for the potential candidate: `>::into(foo_impl)` | note: multiple `impl`s satisfying `Impl: Into<_>` found --> $DIR/E0283.rs:17:1 @@ -24,6 +23,10 @@ LL | impl Into for Impl { = note: and another `impl` found in the `core` crate: - impl Into for T where U: From; +help: use the fully qualified path for the potential candidate + | +LL | let bar = >::into(foo_impl) * 1u32; + | ++++++++++++++++++++++++++ ~ error: aborting due to 2 previous errors diff --git a/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs b/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs new file mode 100644 index 00000000000..9a444be500c --- /dev/null +++ b/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs @@ -0,0 +1,20 @@ +struct Thing(X); + +trait Method { + fn method(self, _: i32) -> T; +} + +impl Method for Thing { + fn method(self, _: i32) -> i32 { 0 } +} + +impl Method for Thing { + fn method(self, _: i32) -> u32 { 0 } +} + +fn main() { + let thing = Thing(true); + thing.method(42); + //~^ ERROR type annotations needed + //~| ERROR type annotations needed +} diff --git a/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.stderr b/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.stderr new file mode 100644 index 00000000000..0e52420ec43 --- /dev/null +++ b/src/test/ui/traits/do-not-mention-type-params-by-name-in-suggestion-issue-96292.stderr @@ -0,0 +1,37 @@ +error[E0282]: type annotations needed + --> $DIR/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs:17:11 + | +LL | thing.method(42); + | ------^^^^^^---- + | | | + | | cannot infer type for type parameter `T` declared on the trait `Method` + | this method call resolves to `T` + +error[E0283]: type annotations needed + --> $DIR/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs:17:11 + | +LL | thing.method(42); + | ------^^^^^^---- + | | | + | | cannot infer type for type parameter `T` declared on the trait `Method` + | this method call resolves to `T` + | +note: multiple `impl`s satisfying `Thing: Method<_>` found + --> $DIR/do-not-mention-type-params-by-name-in-suggestion-issue-96292.rs:7:1 + | +LL | impl Method for Thing { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +... +LL | impl Method for Thing { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ +help: use the fully qualified path for the potential candidates + | +LL | as Method>::method(thing, 42); + | ++++++++++++++++++++++++++++++++++ ~ +LL | as Method>::method(thing, 42); + | ++++++++++++++++++++++++++++++++++ ~ + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0282, E0283. +For more information about an error, try `rustc --explain E0282`. diff --git a/src/test/ui/traits/issue-77982.stderr b/src/test/ui/traits/issue-77982.stderr index 413225d45a6..63c1cb3791e 100644 --- a/src/test/ui/traits/issue-77982.stderr +++ b/src/test/ui/traits/issue-77982.stderr @@ -37,13 +37,13 @@ LL | opts.get(opt.as_ref()); help: use the fully qualified path for the potential candidates | LL | opts.get(>::as_ref(opt)); - | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + | +++++++++++++++++++++++++++++++++ ~ LL | opts.get(>::as_ref(opt)); - | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + | ++++++++++++++++++++++++++++++++ ~ LL | opts.get(>::as_ref(opt)); - | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + | ++++++++++++++++++++++++++++++++ ~ LL | opts.get(>::as_ref(opt)); - | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + | +++++++++++++++++++++++++++++++ ~ and 4 other candidates error[E0283]: type annotations needed