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 34a0f182ab45f..e2d067e012c77 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
@@ -245,6 +245,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
span, "silent safe transmute error"
);
}
+ GetSafeTransmuteErrorAndReason::Default => {
+ (err_msg, None)
+ }
GetSafeTransmuteErrorAndReason::Error {
err_msg,
safe_transmute_explanation,
@@ -2221,6 +2224,12 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
) -> GetSafeTransmuteErrorAndReason {
use rustc_transmute::Answer;
+ // We don't assemble a transmutability candidate for types that are generic
+ // and we should have ambiguity for types that still have non-region infer.
+ if obligation.predicate.has_non_region_param() || obligation.has_non_region_infer() {
+ return GetSafeTransmuteErrorAndReason::Default;
+ }
+
// Erase regions because layout code doesn't particularly care about regions.
let trait_ref =
self.tcx.erase_regions(self.tcx.instantiate_bound_regions_with_erased(trait_ref));
@@ -2243,6 +2252,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
let dst = trait_ref.args.type_at(0);
let src = trait_ref.args.type_at(1);
+
let err_msg = format!("`{src}` cannot be safely transmuted into `{dst}`");
match rustc_transmute::TransmuteTypeEnv::new(self.infcx).is_transmutable(
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
index 109bae10b54cc..becc1acfb6641 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/mod.rs
@@ -43,6 +43,7 @@ pub struct ImplCandidate<'tcx> {
enum GetSafeTransmuteErrorAndReason {
Silent,
+ Default,
Error { err_msg: String, safe_transmute_explanation: Option<String> },
}
diff --git a/compiler/rustc_transmute/src/layout/tree.rs b/compiler/rustc_transmute/src/layout/tree.rs
index 6d5859a5a6563..17eddbfcd7f5e 100644
--- a/compiler/rustc_transmute/src/layout/tree.rs
+++ b/compiler/rustc_transmute/src/layout/tree.rs
@@ -195,10 +195,11 @@ pub(crate) mod rustc {
impl<'tcx> From<&LayoutError<'tcx>> for Err {
fn from(err: &LayoutError<'tcx>) -> Self {
match err {
- LayoutError::Unknown(..) | LayoutError::ReferencesError(..) => Self::UnknownLayout,
+ LayoutError::Unknown(..)
+ | LayoutError::ReferencesError(..)
+ | LayoutError::NormalizationFailure(..) => Self::UnknownLayout,
LayoutError::SizeOverflow(..) => Self::SizeOverflow,
LayoutError::Cycle(err) => Self::TypeError(*err),
- err => unimplemented!("{:?}", err),
}
}
}
diff --git a/tests/crashes/125881.rs b/tests/crashes/125881.rs
deleted file mode 100644
index a38f1891b61d9..0000000000000
--- a/tests/crashes/125881.rs
+++ /dev/null
@@ -1,8 +0,0 @@
-//@ known-bug: rust-lang/rust#125881
-#![crate_type = "lib"]
-#![feature(transmutability)]
-#![feature(unboxed_closures,effects)]
-
-const fn test() -> impl std::mem::TransmuteFrom() {
- || {}
-}
diff --git a/tests/crashes/126377.rs b/tests/crashes/126377.rs
deleted file mode 100644
index f6727bcc0a494..0000000000000
--- a/tests/crashes/126377.rs
+++ /dev/null
@@ -1,29 +0,0 @@
-//@ known-bug: rust-lang/rust#126377
-
-#![feature(effects)]
-#![feature(generic_const_exprs)]
-
-mod assert {
- use std::mem::{Assume, TransmuteFrom};
-
- pub fn is_transmutable<
- Src,
- Dst,
- const ASSUME_ALIGNMENT: bool,
- const ASSUME_LIFETIMES: bool,
- const ASSUME_SAFETY: bool,
- const ASSUME_VALIDITY: bool,
- >()
- where
- Dst: TransmuteFrom<
- Src,
- { }
- >,
- {}
-}
-
-const fn from_options() -> Assume {
- #[repr(C)] struct Src;
- #[repr(C)] struct Dst;
- assert::is_transmutable::<Src, Dst, {0u8}, false, false, false>();
-}
diff --git a/tests/crashes/130413.rs b/tests/crashes/130413.rs
deleted file mode 100644
index 08435ac6450c0..0000000000000
--- a/tests/crashes/130413.rs
+++ /dev/null
@@ -1,17 +0,0 @@
-//@ known-bug: #130413
-
-#![feature(transmutability)]
-trait Aaa {
- type Y;
-}
-
-trait Bbb {
- type B: std::mem::TransmuteFrom<()>;
-}
-
-impl<T> Bbb for T
-where
- T: Aaa,
-{
- type B = T::Y;
-}
diff --git a/tests/ui/transmutability/assoc-bound.rs b/tests/ui/transmutability/assoc-bound.rs
new file mode 100644
index 0000000000000..e8a20b45cde34
--- /dev/null
+++ b/tests/ui/transmutability/assoc-bound.rs
@@ -0,0 +1,25 @@
+#![crate_type = "lib"]
+#![feature(transmutability)]
+
+trait A {
+ type AssocA;
+}
+
+trait B {
+ type AssocB: std::mem::TransmuteFrom<()>;
+}
+
+impl<T> B for (T, u8)
+where
+ T: A,
+{
+ type AssocB = T::AssocA; //~ERROR: the trait bound `<T as A>::AssocA: TransmuteFrom<(), Assume { alignment: false, lifetimes: false, safety: false, validity: false }>` is not satisfied [E0277]
+}
+
+
+impl<T> B for (T, u16)
+where
+ for<'a> &'a i32: A,
+{
+ type AssocB = <&'static i32 as A>::AssocA; //~ERROR: `()` cannot be safely transmuted into `<&i32 as A>::AssocA`
+}
diff --git a/tests/ui/transmutability/assoc-bound.stderr b/tests/ui/transmutability/assoc-bound.stderr
new file mode 100644
index 0000000000000..08d9089439645
--- /dev/null
+++ b/tests/ui/transmutability/assoc-bound.stderr
@@ -0,0 +1,31 @@
+error[E0277]: the trait bound `<T as A>::AssocA: TransmuteFrom<(), Assume { alignment: false, lifetimes: false, safety: false, validity: false }>` is not satisfied
+ --> $DIR/assoc-bound.rs:16:19
+ |
+LL | type AssocB = T::AssocA;
+ | ^^^^^^^^^ the trait `TransmuteFrom<(), Assume { alignment: false, lifetimes: false, safety: false, validity: false }>` is not implemented for `<T as A>::AssocA`
+ |
+note: required by a bound in `B::AssocB`
+ --> $DIR/assoc-bound.rs:9:18
+ |
+LL | type AssocB: std::mem::TransmuteFrom<()>;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `B::AssocB`
+help: consider further restricting the associated type
+ |
+LL | T: A, <T as A>::AssocA: TransmuteFrom<(), Assume { alignment: false, lifetimes: false, safety: false, validity: false }>
+ | ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+error[E0277]: `()` cannot be safely transmuted into `<&i32 as A>::AssocA`
+ --> $DIR/assoc-bound.rs:24:19
+ |
+LL | type AssocB = <&'static i32 as A>::AssocA;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ `<&i32 as A>::AssocA` has an unknown layout
+ |
+note: required by a bound in `B::AssocB`
+ --> $DIR/assoc-bound.rs:9:18
+ |
+LL | type AssocB: std::mem::TransmuteFrom<()>;
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `B::AssocB`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0277`.