diff --git a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
index f07396ce74ffb..4d22e168bb64c 100644
--- a/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
+++ b/compiler/rustc_typeck/src/impl_wf_check/min_specialization.rs
@@ -279,11 +279,16 @@ fn check_predicates<'tcx>(
span: Span,
) {
let tcx = infcx.tcx;
- let impl1_predicates: Vec<_> = traits::elaborate_predicates(
+ let instantiated = tcx.predicates_of(impl1_def_id).instantiate(tcx, impl1_substs);
+ let impl1_predicates: Vec<_> = traits::elaborate_predicates_with_span(
tcx,
- tcx.predicates_of(impl1_def_id).instantiate(tcx, impl1_substs).predicates.into_iter(),
+ std::iter::zip(
+ instantiated.predicates,
+ // Don't drop predicates (unsound!) because `spans` is too short
+ instantiated.spans.into_iter().chain(std::iter::repeat(span)),
+ ),
)
- .map(|obligation| obligation.predicate)
+ .map(|obligation| (obligation.predicate, obligation.cause.span))
.collect();
let mut impl2_predicates = if impl2_node.is_from_trait() {
@@ -321,7 +326,7 @@ fn check_predicates<'tcx>(
// which is sound because we forbid impls like the following
//
// impl<D: Debug> AlwaysApplicable for D { }
- let always_applicable_traits = impl1_predicates.iter().copied().filter(|&predicate| {
+ let always_applicable_traits = impl1_predicates.iter().copied().filter(|&(predicate, _)| {
matches!(
trait_predicate_kind(tcx, predicate),
Some(TraitSpecializationKind::AlwaysApplicable)
@@ -345,11 +350,11 @@ fn check_predicates<'tcx>(
}
}
impl2_predicates.extend(
- traits::elaborate_predicates(tcx, always_applicable_traits)
+ traits::elaborate_predicates_with_span(tcx, always_applicable_traits)
.map(|obligation| obligation.predicate),
);
- for predicate in impl1_predicates {
+ for (predicate, span) in impl1_predicates {
if !impl2_predicates.contains(&predicate) {
check_specialization_on(tcx, predicate, span)
}
@@ -384,9 +389,17 @@ fn check_specialization_on<'tcx>(tcx: TyCtxt<'tcx>, predicate: ty::Predicate<'tc
.emit();
}
}
+ ty::PredicateKind::Projection(ty::ProjectionPredicate { projection_ty, term }) => {
+ tcx.sess
+ .struct_span_err(
+ span,
+ &format!("cannot specialize on associated type `{projection_ty} == {term}`",),
+ )
+ .emit();
+ }
_ => {
tcx.sess
- .struct_span_err(span, &format!("cannot specialize on `{:?}`", predicate))
+ .struct_span_err(span, &format!("cannot specialize on predicate `{}`", predicate))
.emit();
}
}
diff --git a/src/test/ui/specialization/min_specialization/repeated_projection_type.stderr b/src/test/ui/specialization/min_specialization/repeated_projection_type.stderr
index 450984aacc787..a751ba793472e 100644
--- a/src/test/ui/specialization/min_specialization/repeated_projection_type.stderr
+++ b/src/test/ui/specialization/min_specialization/repeated_projection_type.stderr
@@ -1,8 +1,8 @@
-error: cannot specialize on `Binder(ProjectionPredicate(ProjectionTy { substs: [V], item_def_id: DefId(0:6 ~ repeated_projection_type[54ea]::Id::This) }, Ty((I,))), [])`
- --> $DIR/repeated_projection_type.rs:19:1
+error: cannot specialize on associated type `<V as Id>::This == (I,)`
+ --> $DIR/repeated_projection_type.rs:19:15
|
LL | impl<I, V: Id<This = (I,)>> X for V {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^^
error: aborting due to previous error
diff --git a/src/test/ui/specialization/min_specialization/spec-marker-supertraits.stderr b/src/test/ui/specialization/min_specialization/spec-marker-supertraits.stderr
index b1ab58551e680..ba9d6bbe30011 100644
--- a/src/test/ui/specialization/min_specialization/spec-marker-supertraits.stderr
+++ b/src/test/ui/specialization/min_specialization/spec-marker-supertraits.stderr
@@ -1,8 +1,8 @@
error: cannot specialize on trait `HasMethod`
- --> $DIR/spec-marker-supertraits.rs:22:1
+ --> $DIR/spec-marker-supertraits.rs:22:9
|
LL | impl<T: Marker> Spec for T {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^
error: aborting due to previous error
diff --git a/src/test/ui/specialization/min_specialization/specialization_super_trait.stderr b/src/test/ui/specialization/min_specialization/specialization_super_trait.stderr
index 1f2ff99d41568..e935786624b4b 100644
--- a/src/test/ui/specialization/min_specialization/specialization_super_trait.stderr
+++ b/src/test/ui/specialization/min_specialization/specialization_super_trait.stderr
@@ -1,8 +1,8 @@
error: cannot specialize on trait `Default`
- --> $DIR/specialization_super_trait.rs:13:1
+ --> $DIR/specialization_super_trait.rs:13:9
|
LL | impl<T: Default> SpecMarker for T {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^
error: aborting due to previous error
diff --git a/src/test/ui/specialization/min_specialization/specialization_trait.stderr b/src/test/ui/specialization/min_specialization/specialization_trait.stderr
index ecb07ba908eb7..bc87ae0f8b847 100644
--- a/src/test/ui/specialization/min_specialization/specialization_trait.stderr
+++ b/src/test/ui/specialization/min_specialization/specialization_trait.stderr
@@ -11,10 +11,10 @@ LL | impl<T> SpecMarker for (T, T) {
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: cannot specialize on trait `Clone`
- --> $DIR/specialization_trait.rs:21:1
+ --> $DIR/specialization_trait.rs:21:9
|
LL | impl<T: Clone> SpecMarker for [T] {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^
error: aborting due to 3 previous errors
diff --git a/src/test/ui/specialization/min_specialization/specialize_on_trait.stderr b/src/test/ui/specialization/min_specialization/specialize_on_trait.stderr
index 92daddbd8008f..7b79c7eb4ad1c 100644
--- a/src/test/ui/specialization/min_specialization/specialize_on_trait.stderr
+++ b/src/test/ui/specialization/min_specialization/specialize_on_trait.stderr
@@ -1,8 +1,8 @@
error: cannot specialize on trait `SpecMarker`
- --> $DIR/specialize_on_trait.rs:15:1
+ --> $DIR/specialize_on_trait.rs:15:9
|
LL | impl<T: SpecMarker> X for T {
- | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ | ^^^^^^^^^^
error: aborting due to previous error