1 files changed, 19 insertions, 11 deletions

diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
index 18d308f71..b3bf9ad59 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/on_unimplemented.rs
@@ -60,7 +60,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
     ) -> Option<(DefId, SubstsRef<'tcx>)> {
         let tcx = self.tcx;
         let param_env = obligation.param_env;
-        let trait_ref = tcx.erase_late_bound_regions(trait_ref);
+        let trait_ref = self.instantiate_binder_with_placeholders(trait_ref);
         let trait_self_ty = trait_ref.self_ty();
 
         let mut self_match_impls = vec![];
@@ -72,7 +72,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
 
             let impl_self_ty = impl_trait_ref.self_ty();
 
-            if let Ok(..) = self.can_eq(param_env, trait_self_ty, impl_self_ty) {
+            if self.can_eq(param_env, trait_self_ty, impl_self_ty) {
                 self_match_impls.push((def_id, impl_substs));
 
                 if iter::zip(
@@ -149,10 +149,9 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             .unwrap_or_else(|| (trait_ref.def_id(), trait_ref.skip_binder().substs));
         let trait_ref = trait_ref.skip_binder();
 
-        let mut flags = vec![(
-            sym::ItemContext,
-            self.describe_enclosure(obligation.cause.body_id).map(|s| s.to_owned()),
-        )];
+        let body_hir = self.tcx.hir().local_def_id_to_hir_id(obligation.cause.body_id);
+        let mut flags =
+            vec![(sym::ItemContext, self.describe_enclosure(body_hir).map(|s| s.to_owned()))];
 
         match obligation.cause.code() {
             ObligationCauseCode::BuiltinDerivedObligation(..)
@@ -201,7 +200,10 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             if let Some(def) = self_ty.ty_adt_def() {
                 // We also want to be able to select self's original
                 // signature with no type arguments resolved
-                flags.push((sym::_Self, Some(self.tcx.type_of(def.did()).to_string())));
+                flags.push((
+                    sym::_Self,
+                    Some(self.tcx.type_of(def.did()).subst_identity().to_string()),
+                ));
             }
 
             for param in generics.params.iter() {
@@ -219,7 +221,10 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     if let Some(def) = param_ty.ty_adt_def() {
                         // We also want to be able to select the parameter's
                         // original signature with no type arguments resolved
-                        flags.push((name, Some(self.tcx.type_of(def.did()).to_string())));
+                        flags.push((
+                            name,
+                            Some(self.tcx.type_of(def.did()).subst_identity().to_string()),
+                        ));
                     }
                 }
             }
@@ -252,7 +257,10 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 if let Some(def) = aty.ty_adt_def() {
                     // We also want to be able to select the slice's type's original
                     // signature with no type arguments resolved
-                    flags.push((sym::_Self, Some(format!("[{}]", self.tcx.type_of(def.did())))));
+                    flags.push((
+                        sym::_Self,
+                        Some(format!("[{}]", self.tcx.type_of(def.did()).subst_identity())),
+                    ));
                 }
                 if aty.is_integral() {
                     flags.push((sym::_Self, Some("[{integral}]".to_string())));
@@ -262,7 +270,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
             // Arrays give us `[]`, `[{ty}; _]` and `[{ty}; N]`
             if let ty::Array(aty, len) = self_ty.kind() {
                 flags.push((sym::_Self, Some("[]".to_string())));
-                let len = len.kind().try_to_value().and_then(|v| v.try_to_machine_usize(self.tcx));
+                let len = len.kind().try_to_value().and_then(|v| v.try_to_target_usize(self.tcx));
                 flags.push((sym::_Self, Some(format!("[{}; _]", aty))));
                 if let Some(n) = len {
                     flags.push((sym::_Self, Some(format!("[{}; {}]", aty, n))));
@@ -270,7 +278,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                 if let Some(def) = aty.ty_adt_def() {
                     // We also want to be able to select the array's type's original
                     // signature with no type arguments resolved
-                    let def_ty = self.tcx.type_of(def.did());
+                    let def_ty = self.tcx.type_of(def.did()).subst_identity();
                     flags.push((sym::_Self, Some(format!("[{def_ty}; _]"))));
                     if let Some(n) = len {
                         flags.push((sym::_Self, Some(format!("[{def_ty}; {n}]"))));