Do not treat vtable supertraits as distinct when bound with different bound vars

1 files changed, 10 insertions, 4 deletions

diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index d53848f7461..150594ab94d 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1138,11 +1138,12 @@ fn create_mono_items_for_vtable_methods<'tcx>(
         bug!("create_mono_items_for_vtable_methods: {trait_ty:?} not a trait type");
     };
     if let Some(principal) = trait_ty.principal() {
-        let poly_trait_ref = principal.with_self_ty(tcx, impl_ty);
-        assert!(!poly_trait_ref.has_escaping_bound_vars());
+        let trait_ref =
+            tcx.instantiate_bound_regions_with_erased(principal.with_self_ty(tcx, impl_ty));
+        assert!(!trait_ref.has_escaping_bound_vars());
 
         // Walk all methods of the trait, including those of its supertraits
-        let entries = tcx.vtable_entries(poly_trait_ref);
+        let entries = tcx.vtable_entries(trait_ref);
         debug!(?entries);
         let methods = entries
             .iter()
@@ -1197,7 +1198,12 @@ fn collect_alloc<'tcx>(tcx: TyCtxt<'tcx>, alloc_id: AllocId, output: &mut MonoIt
             }
         }
         GlobalAlloc::VTable(ty, dyn_ty) => {
-            let alloc_id = tcx.vtable_allocation((ty, dyn_ty.principal()));
+            let alloc_id = tcx.vtable_allocation((
+                ty,
+                dyn_ty
+                    .principal()
+                    .map(|principal| tcx.instantiate_bound_regions_with_erased(principal)),
+            ));
             collect_alloc(tcx, alloc_id, output)
         }
     }