diff options
3 files changed, 53 insertions, 20 deletions
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 a9029a8cec0..e45108d1713 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 @@ -27,7 +27,7 @@ use std::iter; pub enum TypeAnnotationNeeded { /// ```compile_fail,E0282 - /// let x = "hello".chars().rev().collect(); + /// let x; /// ``` E0282, /// An implementation cannot be chosen unambiguously because of lack of information. diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs index 5e77b5904f6..49fcd25673d 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs @@ -25,7 +25,7 @@ use rustc_errors::{ MultiSpan, Style, }; use rustc_hir as hir; -use rustc_hir::def::Namespace; +use rustc_hir::def::{DefKind, Namespace, Res}; use rustc_hir::def_id::{DefId, LocalDefId}; use rustc_hir::intravisit::Visitor; use rustc_hir::{GenericParam, Item, Node}; @@ -2453,12 +2453,12 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { && let [ .., trait_path_segment @ hir::PathSegment { - res: rustc_hir::def::Res::Def(rustc_hir::def::DefKind::Trait, trait_id), + res: Res::Def(DefKind::Trait, trait_id), .. }, hir::PathSegment { ident: assoc_item_name, - res: rustc_hir::def::Res::Def(_, item_id), + res: Res::Def(_, item_id), .. } ] = path.segments @@ -2469,7 +2469,9 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { let (verb, noun) = match self.tcx.associated_item(item_id).kind { ty::AssocKind::Const => ("refer to the", "constant"), ty::AssocKind::Fn => ("call", "function"), - ty::AssocKind::Type => ("refer to the", "type"), // this is already covered by E0223, but this single match arm doesn't hurt here + // This is already covered by E0223, but this following single match + // arm doesn't hurt here. + ty::AssocKind::Type => ("refer to the", "type"), }; // Replace the more general E0283 with a more specific error @@ -2477,37 +2479,58 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> { err = self.tcx.sess.struct_span_err_with_code( span, format!( - "cannot {verb} associated {noun} on trait without specifying the corresponding `impl` type", + "cannot {verb} associated {noun} on trait without specifying the \ + corresponding `impl` type", ), rustc_errors::error_code!(E0790), ); if let Some(local_def_id) = data.trait_ref.def_id.as_local() - && let Some(hir::Node::Item(hir::Item { ident: trait_name, kind: hir::ItemKind::Trait(_, _, _, _, trait_item_refs), .. })) = self.tcx.hir().find_by_def_id(local_def_id) - && let Some(method_ref) = trait_item_refs.iter().find(|item_ref| item_ref.ident == *assoc_item_name) { - err.span_label(method_ref.span, format!("`{trait_name}::{assoc_item_name}` defined here")); + && let Some(hir::Node::Item(hir::Item { + ident: trait_name, + kind: hir::ItemKind::Trait(_, _, _, _, trait_item_refs), + .. + })) = self.tcx.hir().find_by_def_id(local_def_id) + && let Some(method_ref) = trait_item_refs + .iter() + .find(|item_ref| item_ref.ident == *assoc_item_name) + { + err.span_label( + method_ref.span, + format!("`{trait_name}::{assoc_item_name}` defined here"), + ); } err.span_label(span, format!("cannot {verb} associated {noun} of trait")); let trait_impls = self.tcx.trait_impls_of(data.trait_ref.def_id); - if trait_impls.blanket_impls().is_empty() - && let Some(impl_def_id) = trait_impls.non_blanket_impls().values().flatten().next() + if let Some(impl_def_id) = + trait_impls.non_blanket_impls().values().flatten().next() { - let non_blanket_impl_count = trait_impls.non_blanket_impls().values().flatten().count(); + let non_blanket_impl_count = + trait_impls.non_blanket_impls().values().flatten().count(); // If there is only one implementation of the trait, suggest using it. // Otherwise, use a placeholder comment for the implementation. - let (message, impl_suggestion) = if non_blanket_impl_count == 1 {( - "use the fully-qualified path to the only available implementation", - format!("<{} as ", self.tcx.type_of(impl_def_id).instantiate_identity()) - )} else { - ("use a fully-qualified path to a specific available implementation", - "</* self type */ as ".to_string() - )}; + let (message, self_type) = if non_blanket_impl_count == 1 { + ( + "use the fully-qualified path to the only available \ + implementation", + format!( + "{}", + self.tcx.type_of(impl_def_id).instantiate_identity() + ), + ) + } else { + ( + "use a fully-qualified path to a specific available \ + implementation", + "/* self type */".to_string(), + ) + }; let mut suggestions = vec![( path.span.shrink_to_lo(), - impl_suggestion + format!("<{self_type} as "), )]; if let Some(generic_arg) = trait_path_segment.args { let between_span = trait_path_segment.ident.span.between(generic_arg.span_ext); diff --git a/tests/ui/impl-trait/cross-return-site-inference.stderr b/tests/ui/impl-trait/cross-return-site-inference.stderr index a86e00fa04a..8ee3e9abf9c 100644 --- a/tests/ui/impl-trait/cross-return-site-inference.stderr +++ b/tests/ui/impl-trait/cross-return-site-inference.stderr @@ -14,12 +14,22 @@ error[E0790]: cannot call associated function on trait without specifying the co | LL | return Err(From::from("foo")); | ^^^^^^^^^^ cannot call associated function of trait + | +help: use a fully-qualified path to a specific available implementation + | +LL | return Err(</* self type */ as From>::from("foo")); + | +++++++++++++++++++ + error[E0790]: cannot call associated function on trait without specifying the corresponding `impl` type --> $DIR/cross-return-site-inference.rs:44:9 | LL | Err(From::from("foo")) | ^^^^^^^^^^ cannot call associated function of trait + | +help: use a fully-qualified path to a specific available implementation + | +LL | Err(</* self type */ as From>::from("foo")) + | +++++++++++++++++++ + error: aborting due to 3 previous errors |