diff --git a/compiler/rustc_middle/src/ty/layout.rs b/compiler/rustc_middle/src/ty/layout.rs
index c5a306fdf1f..c1d6856d33c 100644
--- a/compiler/rustc_middle/src/ty/layout.rs
+++ b/compiler/rustc_middle/src/ty/layout.rs
@@ -318,7 +318,13 @@ impl<'tcx> SizeSkeleton<'tcx> {
Ok(layout) => {
return Ok(SizeSkeleton::Known(layout.size));
}
- Err(err) => err,
+ Err(err @ LayoutError::Unknown(_)) => err,
+ // We can't extract SizeSkeleton info from other layout errors
+ Err(
+ e @ LayoutError::Cycle
+ | e @ LayoutError::SizeOverflow(_)
+ | e @ LayoutError::NormalizationFailure(..),
+ ) => return Err(e),
};
match *ty.kind() {
diff --git a/compiler/rustc_ty_utils/src/layout.rs b/compiler/rustc_ty_utils/src/layout.rs
index 7015778e24b..f35f501b902 100644
--- a/compiler/rustc_ty_utils/src/layout.rs
+++ b/compiler/rustc_ty_utils/src/layout.rs
@@ -145,17 +145,20 @@ fn layout_of_uncached<'tcx>(
return Ok(tcx.mk_layout(LayoutS::scalar(cx, data_ptr)));
}
- let unsized_part = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
-
let metadata = if let Some(metadata_def_id) = tcx.lang_items().metadata_type()
// Projection eagerly bails out when the pointee references errors,
// fall back to structurally deducing metadata.
&& !pointee.references_error()
{
- let metadata_ty = tcx.normalize_erasing_regions(
+ let pointee_metadata = tcx.mk_projection(metadata_def_id, [pointee]);
+ let metadata_ty = match tcx.try_normalize_erasing_regions(
param_env,
- tcx.mk_projection(metadata_def_id, [pointee]),
- );
+ pointee_metadata,
+ ) {
+ Ok(metadata_ty) => metadata_ty,
+ Err(err) => return Err(LayoutError::NormalizationFailure(pointee, err)),
+ };
+
let metadata_layout = cx.layout_of(metadata_ty)?;
// If the metadata is a 1-zst, then the pointer is thin.
if metadata_layout.is_zst() && metadata_layout.align.abi.bytes() == 1 {
@@ -163,10 +166,13 @@ fn layout_of_uncached<'tcx>(
}
let Abi::Scalar(metadata) = metadata_layout.abi else {
- return Err(LayoutError::Unknown(unsized_part));
+ return Err(LayoutError::Unknown(pointee));
};
+
metadata
} else {
+ let unsized_part = tcx.struct_tail_erasing_lifetimes(pointee, param_env);
+
match unsized_part.kind() {
ty::Foreign(..) => {
return Ok(tcx.mk_layout(LayoutS::scalar(cx, data_ptr)));
@@ -178,7 +184,7 @@ fn layout_of_uncached<'tcx>(
vtable
}
_ => {
- return Err(LayoutError::Unknown(unsized_part));
+ return Err(LayoutError::Unknown(pointee));
}
}
};
diff --git a/tests/ui/const-generics/issue-112505-overflow.stderr b/tests/ui/const-generics/issue-112505-overflow.stderr
index 0432f2fa8be..bd8a4feeff5 100644
--- a/tests/ui/const-generics/issue-112505-overflow.stderr
+++ b/tests/ui/const-generics/issue-112505-overflow.stderr
@@ -4,8 +4,8 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
LL | unsafe { std::mem::transmute(v) }
| ^^^^^^^^^^^^^^^^^^^
|
- = note: source type: `[[[u32; 8888888]; 9999999]; 777777777]` (values of the type `[[[u32; 8888888]; 9999999]; 777777777]` are too big for the current architecture)
- = note: target type: `[[[u32; 9999999]; 777777777]; 239]` (59484438436515561504 bits)
+ = note: source type: `[[[u32; 8888888]; 9999999]; 777777777]` (values of the type `[[u32; 8888888]; 9999999]` are too big for the current architecture)
+ = note: target type: `[[[u32; 9999999]; 777777777]; 239]` (values of the type `[[u32; 9999999]; 777777777]` are too big for the current architecture)
error: aborting due to previous error
diff --git a/tests/ui/const-generics/transmute-fail.stderr b/tests/ui/const-generics/transmute-fail.stderr
index 3d1197afd0f..9e308620a9c 100644
--- a/tests/ui/const-generics/transmute-fail.stderr
+++ b/tests/ui/const-generics/transmute-fail.stderr
@@ -43,8 +43,8 @@ error[E0512]: cannot transmute between types of different sizes, or dependently-
LL | std::mem::transmute(v)
| ^^^^^^^^^^^^^^^^^^^
|
- = note: source type: `[[[u32; 8888888]; 9999999]; 777777777]` (values of the type `[[[u32; 8888888]; 9999999]; 777777777]` are too big for the current architecture)
- = note: target type: `[[[u32; 9999999]; 777777777]; 8888888]` (values of the type `[[[u32; 9999999]; 777777777]; 8888888]` are too big for the current architecture)
+ = note: source type: `[[[u32; 8888888]; 9999999]; 777777777]` (values of the type `[[u32; 8888888]; 9999999]` are too big for the current architecture)
+ = note: target type: `[[[u32; 9999999]; 777777777]; 8888888]` (values of the type `[[u32; 9999999]; 777777777]` are too big for the current architecture)
error: aborting due to 6 previous errors
diff --git a/tests/ui/layout/cannot-transmute-unnormalizable-type.rs b/tests/ui/layout/cannot-transmute-unnormalizable-type.rs
new file mode 100644
index 00000000000..d2b6e1d8eba
--- /dev/null
+++ b/tests/ui/layout/cannot-transmute-unnormalizable-type.rs
@@ -0,0 +1,22 @@
+trait Trait {
+ type RefTarget;
+}
+
+impl Trait for ()
+where
+ Missing: Trait,
+ //~^ ERROR cannot find type `Missing` in this scope
+{
+ type RefTarget = ();
+}
+
+struct Other {
+ data: <() as Trait>::RefTarget,
+}
+
+fn main() {
+ unsafe {
+ std::mem::transmute::<Option<()>, Option<&Other>>(None);
+ //~^ ERROR cannot transmute between types of different sizes, or dependently-sized types
+ }
+}
diff --git a/tests/ui/layout/cannot-transmute-unnormalizable-type.stderr b/tests/ui/layout/cannot-transmute-unnormalizable-type.stderr
new file mode 100644
index 00000000000..3cfa09ef9d4
--- /dev/null
+++ b/tests/ui/layout/cannot-transmute-unnormalizable-type.stderr
@@ -0,0 +1,19 @@
+error[E0412]: cannot find type `Missing` in this scope
+ --> $DIR/cannot-transmute-unnormalizable-type.rs:7:5
+ |
+LL | Missing: Trait,
+ | ^^^^^^^ not found in this scope
+
+error[E0512]: cannot transmute between types of different sizes, or dependently-sized types
+ --> $DIR/cannot-transmute-unnormalizable-type.rs:19:9
+ |
+LL | std::mem::transmute::<Option<()>, Option<&Other>>(None);
+ | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+ |
+ = note: source type: `Option<()>` (8 bits)
+ = note: target type: `Option<&Other>` (unable to determine layout for `Other` because `<Other as Pointee>::Metadata` cannot be normalized)
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0412, E0512.
+For more information about an error, try `rustc --explain E0412`.