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 a70f881f5fedc..5607fe873f652 100644 --- a/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs +++ b/compiler/rustc_hir_analysis/src/hir_ty_lowering/lint.rs @@ -108,17 +108,20 @@ impl<'tcx> dyn HirTyLowerer<'tcx> + '_ { let tcx = self.tcx(); let parent_id = tcx.hir().get_parent_item(self_ty.hir_id).def_id; if let hir::Node::Item(hir::Item { - kind: - hir::ItemKind::Impl(hir::Impl { - self_ty: impl_self_ty, - of_trait: Some(of_trait_ref), - generics, - .. - }), + kind: hir::ItemKind::Impl(hir::Impl { self_ty: impl_self_ty, of_trait, generics, .. }), .. }) = tcx.hir_node_by_def_id(parent_id) && self_ty.hir_id == impl_self_ty.hir_id { + let Some(of_trait_ref) = of_trait else { + diag.span_suggestion_verbose( + impl_self_ty.span.shrink_to_hi(), + "you might have intended to implement this trait for a given type", + format!(" for /* Type */"), + Applicability::HasPlaceholders, + ); + return; + }; if !of_trait_ref.trait_def_id().is_some_and(|def_id| def_id.is_local()) { return; } diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs index 1889ecc7670ee..824c25db07d2e 100644 --- a/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs +++ b/compiler/rustc_trait_selection/src/error_reporting/traits/fulfillment_errors.rs @@ -1,6 +1,7 @@ use core::ops::ControlFlow; use std::borrow::Cow; +use rustc_ast::TraitObjectSyntax; use rustc_data_structures::fx::FxHashMap; use rustc_data_structures::unord::UnordSet; use rustc_errors::codes::*; @@ -573,7 +574,26 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> { ty::PredicateKind::DynCompatible(trait_def_id) => { let violations = self.tcx.dyn_compatibility_violations(trait_def_id); - report_dyn_incompatibility(self.tcx, span, None, trait_def_id, violations) + let mut err = report_dyn_incompatibility( + self.tcx, + span, + None, + trait_def_id, + violations, + ); + if let hir::Node::Item(item) = + self.tcx.hir_node_by_def_id(obligation.cause.body_id) + && let hir::ItemKind::Impl(impl_) = item.kind + && let None = impl_.of_trait + && let hir::TyKind::TraitObject(_, _, syntax) = impl_.self_ty.kind + && let TraitObjectSyntax::None = syntax + && impl_.self_ty.span.edition().at_least_rust_2021() + { + // Silence the dyn-compatibility error in favor of the missing dyn on + // self type error. #131051. + err.downgrade_to_delayed_bug(); + } + err } ty::PredicateKind::Clause(ty::ClauseKind::WellFormed(ty)) => { diff --git a/tests/ui/traits/missing-for-type-in-impl.e2015.stderr b/tests/ui/traits/missing-for-type-in-impl.e2015.stderr new file mode 100644 index 0000000000000..541b49b024fda --- /dev/null +++ b/tests/ui/traits/missing-for-type-in-impl.e2015.stderr @@ -0,0 +1,74 @@ +warning: trait objects without an explicit `dyn` are deprecated + --> $DIR/missing-for-type-in-impl.rs:8:6 + | +LL | impl Foo { + | ^^^^^^^^ + | + = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021! + = note: for more information, see + = note: `#[warn(bare_trait_objects)]` on by default +help: if this is a dyn-compatible trait, use `dyn` + | +LL | impl dyn Foo { + | +++ +help: you might have intended to implement this trait for a given type + | +LL | impl Foo for /* Type */ { + | ++++++++++++++ + +warning: trait objects without an explicit `dyn` are deprecated + --> $DIR/missing-for-type-in-impl.rs:8:6 + | +LL | impl Foo { + | ^^^^^^^^ + | + = warning: this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021! + = note: for more information, see + = note: duplicate diagnostic emitted due to `-Z deduplicate-diagnostics=no` +help: if this is a dyn-compatible trait, use `dyn` + | +LL | impl dyn Foo { + | +++ +help: you might have intended to implement this trait for a given type + | +LL | impl Foo for /* Type */ { + | ++++++++++++++ + +error[E0038]: the trait `Foo` cannot be made into an object + --> $DIR/missing-for-type-in-impl.rs:8:6 + | +LL | impl Foo { + | ^^^^^^^^ `Foo` cannot be made into an object + | +note: for a trait to be "dyn-compatible" it needs to allow building a vtable to allow the call to be resolvable dynamically; for more information visit + --> $DIR/missing-for-type-in-impl.rs:4:8 + | +LL | trait Foo { + | --- this trait cannot be made into an object... +LL | fn id(me: T) -> T; + | ^^ ...because associated function `id` has no `self` parameter +help: consider turning `id` into a method by giving it a `&self` argument + | +LL | fn id(&self, me: T) -> T; + | ++++++ +help: alternatively, consider constraining `id` so it does not apply to trait objects + | +LL | fn id(me: T) -> T where Self: Sized; + | +++++++++++++++++ + +error[E0277]: the trait bound `i64: Foo` is not satisfied + --> $DIR/missing-for-type-in-impl.rs:19:19 + | +LL | let x: i64 = >::id(10); + | ^^^ the trait `Foo` is not implemented for `i64` + | +help: this trait has no implementations, consider adding one + --> $DIR/missing-for-type-in-impl.rs:3:1 + | +LL | trait Foo { + | ^^^^^^^^^^^^ + +error: aborting due to 2 previous errors; 2 warnings emitted + +Some errors have detailed explanations: E0038, E0277. +For more information about an error, try `rustc --explain E0038`. diff --git a/tests/ui/traits/missing-for-type-in-impl.e2021.stderr b/tests/ui/traits/missing-for-type-in-impl.e2021.stderr new file mode 100644 index 0000000000000..b5a607a54cb54 --- /dev/null +++ b/tests/ui/traits/missing-for-type-in-impl.e2021.stderr @@ -0,0 +1,31 @@ +error[E0277]: the trait bound `i64: Foo` is not satisfied + --> $DIR/missing-for-type-in-impl.rs:19:19 + | +LL | let x: i64 = >::id(10); + | ^^^ the trait `Foo` is not implemented for `i64` + | +help: this trait has no implementations, consider adding one + --> $DIR/missing-for-type-in-impl.rs:3:1 + | +LL | trait Foo { + | ^^^^^^^^^^^^ + +error[E0782]: trait objects must include the `dyn` keyword + --> $DIR/missing-for-type-in-impl.rs:8:6 + | +LL | impl Foo { + | ^^^^^^^^ + | +help: add `dyn` keyword before this trait + | +LL | impl dyn Foo { + | +++ +help: you might have intended to implement this trait for a given type + | +LL | impl Foo for /* Type */ { + | ++++++++++++++ + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0277, E0782. +For more information about an error, try `rustc --explain E0277`. diff --git a/tests/ui/traits/missing-for-type-in-impl.rs b/tests/ui/traits/missing-for-type-in-impl.rs new file mode 100644 index 0000000000000..7d4ad479e773c --- /dev/null +++ b/tests/ui/traits/missing-for-type-in-impl.rs @@ -0,0 +1,22 @@ +//@revisions: e2021 e2015 +//@[e2021]edition: 2021 +trait Foo { + fn id(me: T) -> T; +} + +/* note the "missing" for ... (in this case for i64, in order for this to compile) */ +impl Foo { +//[e2021]~^ ERROR trait objects must include the `dyn` keyword +//[e2015]~^^ WARNING trait objects without an explicit `dyn` are deprecated +//[e2015]~| WARNING trait objects without an explicit `dyn` are deprecated +//[e2015]~| WARNING this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021! +//[e2015]~| WARNING this is accepted in the current edition (Rust 2015) but is a hard error in Rust 2021! +//[e2015]~| ERROR the trait `Foo` cannot be made into an object + fn id(me: i64) -> i64 {me} +} + +fn main() { + let x: i64 = >::id(10); + //~^ ERROR the trait bound `i64: Foo` is not satisfied + println!("{}", x); +}