diff options
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/query/normalize.rs | 8 | ||||
| -rw-r--r-- | tests/ui/type-alias-impl-trait/debug-ty-with-weak.rs | 12 |
2 files changed, 18 insertions, 2 deletions
diff --git a/compiler/rustc_trait_selection/src/traits/query/normalize.rs b/compiler/rustc_trait_selection/src/traits/query/normalize.rs index 2d97a808225..1b6e92946c4 100644 --- a/compiler/rustc_trait_selection/src/traits/query/normalize.rs +++ b/compiler/rustc_trait_selection/src/traits/query/normalize.rs @@ -322,8 +322,12 @@ impl<'cx, 'tcx> FallibleTypeFolder<TyCtxt<'tcx>> for QueryNormalizer<'cx, 'tcx> }; // `tcx.normalize_projection_ty` may normalize to a type that still has // unevaluated consts, so keep normalizing here if that's the case. - if res != ty && res.has_type_flags(ty::TypeFlags::HAS_CT_PROJECTION) { - res.try_super_fold_with(self)? + // Similarly, `tcx.normalize_weak_ty` will only unwrap one layer of type + // and we need to continue folding it to reveal the TAIT behind it. + if res != ty + && (res.has_type_flags(ty::TypeFlags::HAS_CT_PROJECTION) || kind == ty::Weak) + { + res.try_fold_with(self)? } else { res } diff --git a/tests/ui/type-alias-impl-trait/debug-ty-with-weak.rs b/tests/ui/type-alias-impl-trait/debug-ty-with-weak.rs new file mode 100644 index 00000000000..44158349fdd --- /dev/null +++ b/tests/ui/type-alias-impl-trait/debug-ty-with-weak.rs @@ -0,0 +1,12 @@ +// compile-flags: --crate-type=lib -Cdebuginfo=2 +// build-pass + +#![feature(type_alias_impl_trait)] + +type Debuggable = impl core::fmt::Debug; + +static mut TEST: Option<Debuggable> = None; + +fn foo() -> Debuggable { + 0u32 +} |