diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index d2ac24b6100..c52fd0b5786 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -461,10 +461,17 @@ fn virtual_call_violation_for_method<'tcx>(
let param_env = tcx.param_env(method.def_id);
- let abi_of_ty = |ty: Ty<'tcx>| -> &Abi {
+ let abi_of_ty = |ty: Ty<'tcx>| -> Option<&Abi> {
match tcx.layout_of(param_env.and(ty)) {
- Ok(layout) => &layout.abi,
- Err(err) => bug!("error: {}\n while computing layout for type {:?}", err, ty),
+ Ok(layout) => Some(&layout.abi),
+ Err(err) => {
+ // #78372
+ tcx.sess.delay_span_bug(
+ tcx.def_span(method.def_id),
+ &format!("error: {}\n while computing layout for type {:?}", err, ty),
+ );
+ None
+ }
}
};
@@ -473,7 +480,7 @@ fn virtual_call_violation_for_method<'tcx>(
receiver_for_self_ty(tcx, receiver_ty, tcx.mk_unit(), method.def_id);
match abi_of_ty(unit_receiver_ty) {
- &Abi::Scalar(..) => (),
+ Some(Abi::Scalar(..)) => (),
abi => {
tcx.sess.delay_span_bug(
tcx.def_span(method.def_id),
@@ -493,13 +500,12 @@ fn virtual_call_violation_for_method<'tcx>(
receiver_for_self_ty(tcx, receiver_ty, trait_object_ty, method.def_id);
match abi_of_ty(trait_object_receiver) {
- &Abi::ScalarPair(..) => (),
+ Some(Abi::ScalarPair(..)) => (),
abi => {
tcx.sess.delay_span_bug(
tcx.def_span(method.def_id),
&format!(
- "receiver when `Self = {}` should have a ScalarPair ABI; \
- found {:?}",
+ "receiver when `Self = {}` should have a ScalarPair ABI; found {:?}",
trait_object_ty, abi
),
);
diff --git a/src/test/ui/issues/issue-78372.rs b/src/test/ui/issues/issue-78372.rs
new file mode 100644
index 00000000000..77a8c92c81c
--- /dev/null
+++ b/src/test/ui/issues/issue-78372.rs
@@ -0,0 +1,14 @@
+use std::ops::DispatchFromDyn; //~ ERROR use of unstable library feature 'dispatch_from_dyn'
+struct Smaht<T, MISC>(PhantomData); //~ ERROR cannot find type `PhantomData` in this scope
+impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {} //~ ERROR cannot find type `U` in this scope
+//~^ ERROR cannot find type `MISC` in this scope
+//~| ERROR use of unstable library feature 'dispatch_from_dyn'
+//~| ERROR the trait `DispatchFromDyn` may only be implemented for a coercion between structures
+//~| ERROR type parameter `T` must be covered by another type when it appears before the first
+trait Foo: X<u32> {}
+trait X<T> {
+ fn foo(self: Smaht<Self, T>);
+}
+trait Marker {}
+impl Marker for dyn Foo {}
+fn main() {}
diff --git a/src/test/ui/issues/issue-78372.stderr b/src/test/ui/issues/issue-78372.stderr
new file mode 100644
index 00000000000..9267e838cea
--- /dev/null
+++ b/src/test/ui/issues/issue-78372.stderr
@@ -0,0 +1,62 @@
+error[E0412]: cannot find type `PhantomData` in this scope
+ --> $DIR/issue-78372.rs:2:23
+ |
+LL | struct Smaht<T, MISC>(PhantomData);
+ | ^^^^^^^^^^^ not found in this scope
+ |
+help: consider importing this struct
+ |
+LL | use std::marker::PhantomData;
+ |
+
+error[E0412]: cannot find type `U` in this scope
+ --> $DIR/issue-78372.rs:3:31
+ |
+LL | impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {}
+ | - ^ help: a type parameter with a similar name exists: `T`
+ | |
+ | similarly named type parameter `T` defined here
+
+error[E0412]: cannot find type `MISC` in this scope
+ --> $DIR/issue-78372.rs:3:34
+ |
+LL | impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {}
+ | - ^^^^ not found in this scope
+ | |
+ | help: you might be missing a type parameter: `, MISC`
+
+error[E0658]: use of unstable library feature 'dispatch_from_dyn'
+ --> $DIR/issue-78372.rs:1:5
+ |
+LL | use std::ops::DispatchFromDyn;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: add `#![feature(dispatch_from_dyn)]` to the crate attributes to enable
+
+error[E0658]: use of unstable library feature 'dispatch_from_dyn'
+ --> $DIR/issue-78372.rs:3:9
+ |
+LL | impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = help: add `#![feature(dispatch_from_dyn)]` to the crate attributes to enable
+
+error[E0378]: the trait `DispatchFromDyn` may only be implemented for a coercion between structures
+ --> $DIR/issue-78372.rs:3:1
+ |
+LL | impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {}
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error[E0210]: type parameter `T` must be covered by another type when it appears before the first local type (`Smaht<[type error], [type error]>`)
+ --> $DIR/issue-78372.rs:3:6
+ |
+LL | impl<T> DispatchFromDyn<Smaht<U, MISC>> for T {}
+ | ^ type parameter `T` must be covered by another type when it appears before the first local type (`Smaht<[type error], [type error]>`)
+ |
+ = note: implementing a foreign trait is only possible if at least one of the types for which it is implemented is local, and no uncovered type parameters appear before that first local type
+ = note: in this case, 'before' refers to the following order: `impl<..> ForeignTrait<T1, ..., Tn> for T0`, where `T0` is the first and `Tn` is the last
+
+error: aborting due to 7 previous errors
+
+Some errors have detailed explanations: E0210, E0378, E0412, E0658.
+For more information about an error, try `rustc --explain E0210`.