Auto merge of #110806 - WaffleLapkin:unmkI, r=lcnr

Replace `tcx.mk_trait_ref` with `TraitRef::new`

First step in implementing https://github.com/rust-lang/compiler-team/issues/616
r? `@lcnr`

17 files changed, 77 insertions, 72 deletions

diff --git a/compiler/rustc_trait_selection/src/infer.rs b/compiler/rustc_trait_selection/src/infer.rs
index fcf86da08f4..142c20014a0 100644
--- a/compiler/rustc_trait_selection/src/infer.rs
+++ b/compiler/rustc_trait_selection/src/infer.rs
@@ -66,7 +66,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
         params: impl IntoIterator<Item: Into<GenericArg<'tcx>>>,
         param_env: ty::ParamEnv<'tcx>,
     ) -> traits::EvaluationResult {
-        let trait_ref = self.tcx.mk_trait_ref(trait_def_id, params);
+        let trait_ref = ty::TraitRef::new(self.tcx, trait_def_id, params);
 
         let obligation = traits::Obligation {
             cause: traits::ObligationCause::dummy(),
diff --git a/compiler/rustc_trait_selection/src/solve/project_goals.rs b/compiler/rustc_trait_selection/src/solve/project_goals.rs
index f0840e0443c..e5d51064c8d 100644
--- a/compiler/rustc_trait_selection/src/solve/project_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/project_goals.rs
@@ -274,8 +274,9 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
                         .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
                 }
             };
-        let output_is_sized_pred = tupled_inputs_and_output
-            .map_bound(|(_, output)| tcx.at(DUMMY_SP).mk_trait_ref(LangItem::Sized, [output]));
+        let output_is_sized_pred = tupled_inputs_and_output.map_bound(|(_, output)| {
+            ty::TraitRef::from_lang_item(tcx, LangItem::Sized, DUMMY_SP, [output])
+        });
 
         let pred = tupled_inputs_and_output
             .map_bound(|(inputs, output)| ty::ProjectionPredicate {
@@ -333,10 +334,12 @@ impl<'tcx> assembly::GoalKind<'tcx> for ProjectionPredicate<'tcx> {
 
                 ty::Alias(_, _) | ty::Param(_) | ty::Placeholder(..) => {
                     // FIXME(ptr_metadata): It would also be possible to return a `Ok(Ambig)` with no constraints.
-                    let sized_predicate = ty::Binder::dummy(tcx.at(DUMMY_SP).mk_trait_ref(
+                    let sized_predicate = ty::TraitRef::from_lang_item(
+                        tcx,
                         LangItem::Sized,
+                        DUMMY_SP,
                         [ty::GenericArg::from(goal.predicate.self_ty())],
-                    ));
+                    );
                     ecx.add_goal(goal.with(tcx, sized_predicate));
                     tcx.types.unit
                 }
diff --git a/compiler/rustc_trait_selection/src/solve/trait_goals.rs b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
index c97473e6241..6c98fadd148 100644
--- a/compiler/rustc_trait_selection/src/solve/trait_goals.rs
+++ b/compiler/rustc_trait_selection/src/solve/trait_goals.rs
@@ -272,12 +272,13 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
                         .evaluate_added_goals_and_make_canonical_response(Certainty::AMBIGUOUS);
                 }
             };
-        let output_is_sized_pred = tupled_inputs_and_output
-            .map_bound(|(_, output)| tcx.at(DUMMY_SP).mk_trait_ref(LangItem::Sized, [output]));
+        let output_is_sized_pred = tupled_inputs_and_output.map_bound(|(_, output)| {
+            ty::TraitRef::from_lang_item(tcx, LangItem::Sized, DUMMY_SP, [output])
+        });
 
         let pred = tupled_inputs_and_output
             .map_bound(|(inputs, _)| {
-                tcx.mk_trait_ref(goal.predicate.def_id(), [goal.predicate.self_ty(), inputs])
+                ty::TraitRef::new(tcx, goal.predicate.def_id(), [goal.predicate.self_ty(), inputs])
             })
             .to_predicate(tcx);
         // A built-in `Fn` impl only holds if the output is sized.
@@ -358,10 +359,8 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
         Self::consider_implied_clause(
             ecx,
             goal,
-            ty::Binder::dummy(
-                tcx.mk_trait_ref(goal.predicate.def_id(), [self_ty, generator.resume_ty()]),
-            )
-            .to_predicate(tcx),
+            ty::TraitRef::new(tcx, goal.predicate.def_id(), [self_ty, generator.resume_ty()])
+                .to_predicate(tcx),
             // Technically, we need to check that the generator types are Sized,
             // but that's already proven by the generator being WF.
             [],
@@ -410,9 +409,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
                         data.iter().map(|pred| goal.with(tcx, pred.with_self_ty(tcx, a_ty))),
                     );
                     // The type must be Sized to be unsized.
-                    ecx.add_goal(
-                        goal.with(tcx, ty::Binder::dummy(tcx.mk_trait_ref(sized_def_id, [a_ty]))),
-                    );
+                    ecx.add_goal(goal.with(tcx, ty::TraitRef::new(tcx, sized_def_id, [a_ty])));
                     // The type must outlive the lifetime of the `dyn` we're unsizing into.
                     ecx.add_goal(
                         goal.with(tcx, ty::Binder::dummy(ty::OutlivesPredicate(a_ty, region))),
@@ -461,9 +458,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
                     ecx.eq(goal.param_env, unsized_a_ty, b_ty)?;
                     ecx.add_goal(goal.with(
                         tcx,
-                        ty::Binder::dummy(
-                            tcx.mk_trait_ref(goal.predicate.def_id(), [a_tail_ty, b_tail_ty]),
-                        ),
+                        ty::TraitRef::new(tcx, goal.predicate.def_id(), [a_tail_ty, b_tail_ty]),
                     ));
                     ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
                 }
@@ -482,9 +477,7 @@ impl<'tcx> assembly::GoalKind<'tcx> for TraitPredicate<'tcx> {
                     // Similar to ADTs, require that the rest of the fields are equal.
                     ecx.add_goal(goal.with(
                         tcx,
-                        ty::Binder::dummy(
-                            tcx.mk_trait_ref(goal.predicate.def_id(), [*a_last_ty, *b_last_ty]),
-                        ),
+                        ty::TraitRef::new(tcx, goal.predicate.def_id(), [*a_last_ty, *b_last_ty]),
                     ));
                     ecx.evaluate_added_goals_and_make_canonical_response(Certainty::Yes)
                 }
diff --git a/compiler/rustc_trait_selection/src/traits/auto_trait.rs b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
index e82672e8368..6b080a132f3 100644
--- a/compiler/rustc_trait_selection/src/traits/auto_trait.rs
+++ b/compiler/rustc_trait_selection/src/traits/auto_trait.rs
@@ -86,7 +86,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
     ) -> AutoTraitResult<A> {
         let tcx = self.tcx;
 
-        let trait_ref = tcx.mk_trait_ref(trait_did, [ty]);
+        let trait_ref = ty::TraitRef::new(tcx, trait_did, [ty]);
 
         let infcx = tcx.infer_ctxt().build();
         let mut selcx = SelectionContext::new(&infcx);
@@ -263,7 +263,7 @@ impl<'tcx> AutoTraitFinder<'tcx> {
         let mut already_visited = FxHashSet::default();
         let mut predicates = VecDeque::new();
         predicates.push_back(ty::Binder::dummy(ty::TraitPredicate {
-            trait_ref: infcx.tcx.mk_trait_ref(trait_did, [ty]),
+            trait_ref: ty::TraitRef::new(infcx.tcx, trait_did, [ty]),
 
             constness: ty::BoundConstness::NotConst,
             // Auto traits are positive
diff --git a/compiler/rustc_trait_selection/src/traits/engine.rs b/compiler/rustc_trait_selection/src/traits/engine.rs
index 2beebe94b6d..000427bbe83 100644
--- a/compiler/rustc_trait_selection/src/traits/engine.rs
+++ b/compiler/rustc_trait_selection/src/traits/engine.rs
@@ -97,7 +97,7 @@ impl<'a, 'tcx> ObligationCtxt<'a, 'tcx> {
         def_id: DefId,
     ) {
         let tcx = self.infcx.tcx;
-        let trait_ref = tcx.mk_trait_ref(def_id, [ty]);
+        let trait_ref = ty::TraitRef::new(tcx, def_id, [ty]);
         self.register_obligation(Obligation {
             cause,
             recursion_depth: 0,
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
index 0475f24d87c..7ab652761a4 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/ambiguity.rs
@@ -87,7 +87,7 @@ pub fn recompute_applicable_impls<'tcx>(
         if let ty::PredicateKind::Clause(ty::Clause::Trait(trait_pred)) = kind.skip_binder()
             && param_env_candidate_may_apply(kind.rebind(trait_pred))
         {
-            if kind.rebind(trait_pred.trait_ref) == ty::TraitRef::identity(tcx, trait_pred.def_id()) {
+            if kind.rebind(trait_pred.trait_ref) == ty::Binder::dummy(ty::TraitRef::identity(tcx, trait_pred.def_id())) {
                 ambiguities.push(Ambiguity::ParamEnv(tcx.def_span(trait_pred.def_id())))
             } else {
                 ambiguities.push(Ambiguity::ParamEnv(span))
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
index 69b3c1e7eff..8f2a5d649f0 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs
@@ -358,7 +358,7 @@ impl<'tcx> InferCtxtExt<'tcx> for InferCtxt<'tcx> {
                     span: DUMMY_SP,
                     kind: TypeVariableOriginKind::MiscVariable,
                 });
-                let trait_ref = self.tcx.mk_trait_ref(trait_def_id, [ty.skip_binder(), var]);
+                let trait_ref = ty::TraitRef::new(self.tcx, trait_def_id, [ty.skip_binder(), var]);
                 let obligation = Obligation::new(
                     self.tcx,
                     ObligationCause::dummy(),
diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
index 3e9e497672a..d34eb193453 100644
--- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs
@@ -3502,7 +3502,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                         _ => None,
                     };
                     let trait_pred = trait_pred.map_bound_ref(|tr| ty::TraitPredicate {
-                        trait_ref: self.tcx.mk_trait_ref(
+                        trait_ref: ty::TraitRef::new(self.tcx,
                             trait_pred.def_id(),
                             [field_ty].into_iter().chain(trait_substs),
                         ),
diff --git a/compiler/rustc_trait_selection/src/traits/mod.rs b/compiler/rustc_trait_selection/src/traits/mod.rs
index 0e8c74a6765..8b8c50f6b83 100644
--- a/compiler/rustc_trait_selection/src/traits/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/mod.rs
@@ -127,7 +127,7 @@ pub fn type_known_to_meet_bound_modulo_regions<'tcx>(
     ty: Ty<'tcx>,
     def_id: DefId,
 ) -> bool {
-    let trait_ref = ty::Binder::dummy(infcx.tcx.mk_trait_ref(def_id, [ty]));
+    let trait_ref = ty::TraitRef::new(infcx.tcx, def_id, [ty]);
     pred_known_to_hold_modulo_regions(infcx, param_env, trait_ref.without_const())
 }
 
diff --git a/compiler/rustc_trait_selection/src/traits/object_safety.rs b/compiler/rustc_trait_selection/src/traits/object_safety.rs
index 384b6ae93a1..06d9c10386e 100644
--- a/compiler/rustc_trait_selection/src/traits/object_safety.rs
+++ b/compiler/rustc_trait_selection/src/traits/object_safety.rs
@@ -279,7 +279,7 @@ fn predicates_reference_self(
     trait_def_id: DefId,
     supertraits_only: bool,
 ) -> SmallVec<[Span; 1]> {
-    let trait_ref = ty::TraitRef::identity(tcx, trait_def_id);
+    let trait_ref = ty::Binder::dummy(ty::TraitRef::identity(tcx, trait_def_id));
     let predicates = if supertraits_only {
         tcx.super_predicates_of(trait_def_id)
     } else {
@@ -661,9 +661,9 @@ fn object_ty_for_trait<'tcx>(
     let trait_ref = ty::TraitRef::identity(tcx, trait_def_id);
     debug!(?trait_ref);
 
-    let trait_predicate = trait_ref.map_bound(|trait_ref| {
-        ty::ExistentialPredicate::Trait(ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref))
-    });
+    let trait_predicate = ty::Binder::dummy(ty::ExistentialPredicate::Trait(
+        ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref),
+    ));
     debug!(?trait_predicate);
 
     let pred: ty::Predicate<'tcx> = trait_ref.to_predicate(tcx);
@@ -769,11 +769,10 @@ fn receiver_is_dispatchable<'tcx>(
         let param_env = tcx.param_env(method.def_id);
 
         // Self: Unsize<U>
-        let unsize_predicate = ty::Binder::dummy(
-            tcx.mk_trait_ref(unsize_did, [tcx.types.self_param, unsized_self_ty]),
-        )
-        .without_const()
-        .to_predicate(tcx);
+        let unsize_predicate =
+            ty::TraitRef::new(tcx, unsize_did, [tcx.types.self_param, unsized_self_ty])
+                .without_const()
+                .to_predicate(tcx);
 
         // U: Trait<Arg1, ..., ArgN>
         let trait_predicate = {
@@ -782,7 +781,7 @@ fn receiver_is_dispatchable<'tcx>(
                 if param.index == 0 { unsized_self_ty.into() } else { tcx.mk_param_from_def(param) }
             });
 
-            ty::Binder::dummy(tcx.mk_trait_ref(trait_def_id, substs)).to_predicate(tcx)
+            ty::TraitRef::new(tcx, trait_def_id, substs).to_predicate(tcx)
         };
 
         let caller_bounds =
@@ -797,9 +796,8 @@ fn receiver_is_dispatchable<'tcx>(
 
     // Receiver: DispatchFromDyn<Receiver[Self => U]>
     let obligation = {
-        let predicate = ty::Binder::dummy(
-            tcx.mk_trait_ref(dispatch_from_dyn_did, [receiver_ty, unsized_receiver_ty]),
-        );
+        let predicate =
+            ty::TraitRef::new(tcx, dispatch_from_dyn_did, [receiver_ty, unsized_receiver_ty]);
 
         Obligation::new(tcx, ObligationCause::dummy(), param_env, predicate)
     };
@@ -882,7 +880,8 @@ fn contains_illegal_self_type_reference<'tcx, T: TypeVisitable<TyCtxt<'tcx>>>(
 
                     // Compute supertraits of current trait lazily.
                     if self.supertraits.is_none() {
-                        let trait_ref = ty::TraitRef::identity(self.tcx, self.trait_def_id);
+                        let trait_ref =
+                            ty::Binder::dummy(ty::TraitRef::identity(self.tcx, self.trait_def_id));
                         self.supertraits = Some(
                             traits::supertraits(self.tcx, trait_ref).map(|t| t.def_id()).collect(),
                         );
diff --git a/compiler/rustc_trait_selection/src/traits/project.rs b/compiler/rustc_trait_selection/src/traits/project.rs
index 4369b257f5f..8c74860cdf3 100644
--- a/compiler/rustc_trait_selection/src/traits/project.rs
+++ b/compiler/rustc_trait_selection/src/traits/project.rs
@@ -1319,7 +1319,7 @@ fn assemble_candidate_for_impl_trait_in_trait<'cx, 'tcx>(
         let trait_substs =
             obligation.predicate.substs.truncate_to(tcx, tcx.generics_of(trait_def_id));
         // FIXME(named-returns): Binders
-        let trait_predicate = ty::Binder::dummy(tcx.mk_trait_ref(trait_def_id, trait_substs));
+        let trait_predicate = ty::TraitRef::new(tcx, trait_def_id, trait_substs);
 
         let _ = selcx.infcx.commit_if_ok(|_| {
             match selcx.select(&obligation.with(tcx, trait_predicate)) {
@@ -1682,10 +1682,8 @@ fn assemble_candidates_from_impls<'cx, 'tcx>(
                             if selcx.infcx.predicate_must_hold_modulo_regions(
                                 &obligation.with(
                                     selcx.tcx(),
-                                    ty::Binder::dummy(
-                                        selcx.tcx().at(obligation.cause.span()).mk_trait_ref(LangItem::Sized, [self_ty]),
-                                    )
-                                    .without_const(),
+                                    ty::TraitRef::from_lang_item(selcx.tcx(), LangItem::Sized, obligation.cause.span(),[self_ty])
+                                        .without_const(),
                                 ),
                             ) =>
                         {
@@ -1948,8 +1946,11 @@ fn confirm_builtin_candidate<'cx, 'tcx>(
             )
         });
         if check_is_sized {
-            let sized_predicate = ty::Binder::dummy(
-                tcx.at(obligation.cause.span()).mk_trait_ref(LangItem::Sized, [self_ty]),
+            let sized_predicate = ty::TraitRef::from_lang_item(
+                tcx,
+                LangItem::Sized,
+                obligation.cause.span(),
+                [self_ty],
             )
             .without_const();
             obligations.push(obligation.with(tcx, sized_predicate));
diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
index a8864f47ef0..33f502f8182 100644
--- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs
@@ -459,7 +459,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 obligation.param_env,
                 self.tcx().mk_predicate(obligation.predicate.map_bound(|mut pred| {
                     pred.trait_ref =
-                        self.tcx().mk_trait_ref(fn_ptr_trait, [pred.trait_ref.self_ty()]);
+                        ty::TraitRef::new(self.tcx(), fn_ptr_trait, [pred.trait_ref.self_ty()]);
                     ty::PredicateKind::Clause(ty::Clause::Trait(pred))
                 })),
             );
@@ -634,7 +634,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         }
 
         // <ty as Deref>
-        let trait_ref = tcx.mk_trait_ref(tcx.lang_items().deref_trait()?, [ty]);
+        let trait_ref = ty::TraitRef::new(tcx, tcx.lang_items().deref_trait()?, [ty]);
 
         let obligation =
             traits::Obligation::new(tcx, cause.clone(), param_env, ty::Binder::dummy(trait_ref));
diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
index 3bba11262f5..422285d9474 100644
--- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs
@@ -646,8 +646,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
             output_ty,
             &mut nested,
         );
-        let tr =
-            ty::Binder::dummy(self.tcx().at(cause.span).mk_trait_ref(LangItem::Sized, [output_ty]));
+        let tr = ty::TraitRef::from_lang_item(self.tcx(), LangItem::Sized, cause.span, [output_ty]);
         nested.push(Obligation::new(self.infcx.tcx, cause, obligation.param_env, tr));
 
         Ok(ImplSourceFnPointerData { fn_ty: self_ty, nested })
@@ -1050,8 +1049,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 );
 
                 // We can only make objects from sized types.
-                let tr =
-                    ty::Binder::dummy(tcx.at(cause.span).mk_trait_ref(LangItem::Sized, [source]));
+                let tr = ty::TraitRef::from_lang_item(tcx, LangItem::Sized, cause.span, [source]);
                 nested.push(predicate_to_obligation(tr.without_const().to_predicate(tcx)));
 
                 // If the type is `Foo + 'a`, ensure that the type
@@ -1121,7 +1119,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 // Construct the nested `TailField<T>: Unsize<TailField<U>>` predicate.
                 let tail_unsize_obligation = obligation.with(
                     tcx,
-                    tcx.mk_trait_ref(obligation.predicate.def_id(), [source_tail, target_tail]),
+                    ty::TraitRef::new(
+                        tcx,
+                        obligation.predicate.def_id(),
+                        [source_tail, target_tail],
+                    ),
                 );
                 nested.push(tail_unsize_obligation);
             }
@@ -1146,8 +1148,10 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 nested.extend(obligations);
 
                 // Add a nested `T: Unsize<U>` predicate.
-                let last_unsize_obligation = obligation
-                    .with(tcx, tcx.mk_trait_ref(obligation.predicate.def_id(), [a_last, b_last]));
+                let last_unsize_obligation = obligation.with(
+                    tcx,
+                    ty::TraitRef::new(tcx, obligation.predicate.def_id(), [a_last, b_last]),
+                );
                 nested.push(last_unsize_obligation);
             }
 
@@ -1271,10 +1275,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                         cause.clone(),
                         obligation.recursion_depth + 1,
                         self_ty.rebind(ty::TraitPredicate {
-                            trait_ref: self
-                                .tcx()
-                                .at(cause.span)
-                                .mk_trait_ref(LangItem::Destruct, [nested_ty]),
+                            trait_ref: ty::TraitRef::from_lang_item(
+                                self.tcx(),
+                                LangItem::Destruct,
+                                cause.span,
+                                [nested_ty],
+                            ),
                             constness: ty::BoundConstness::ConstIfConst,
                             polarity: ty::ImplPolarity::Positive,
                         }),
@@ -1295,10 +1301,12 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 // or it's an ADT (and we need to check for a custom impl during selection)
                 _ => {
                     let predicate = self_ty.rebind(ty::TraitPredicate {
-                        trait_ref: self
-                            .tcx()
-                            .at(cause.span)
-                            .mk_trait_ref(LangItem::Destruct, [nested_ty]),
+                        trait_ref: ty::TraitRef::from_lang_item(
+                            self.tcx(),
+                            LangItem::Destruct,
+                            cause.span,
+                            [nested_ty],
+                        ),
                         constness: ty::BoundConstness::ConstIfConst,
                         polarity: ty::ImplPolarity::Positive,
                     });
diff --git a/compiler/rustc_trait_selection/src/traits/select/mod.rs b/compiler/rustc_trait_selection/src/traits/select/mod.rs
index 9890e990eeb..246d3ea2ef2 100644
--- a/compiler/rustc_trait_selection/src/traits/select/mod.rs
+++ b/compiler/rustc_trait_selection/src/traits/select/mod.rs
@@ -2413,7 +2413,7 @@ impl<'tcx> SelectionContext<'_, 'tcx> {
                     self.tcx(),
                     cause.clone(),
                     param_env,
-                    self.tcx().mk_trait_ref(trait_def_id, [normalized_ty]),
+                    ty::TraitRef::new(self.tcx(), trait_def_id, [normalized_ty]),
                 );
                 obligations.push(obligation);
                 obligations
diff --git a/compiler/rustc_trait_selection/src/traits/util.rs b/compiler/rustc_trait_selection/src/traits/util.rs
index 7792ceabe7e..7b7e297c64b 100644
--- a/compiler/rustc_trait_selection/src/traits/util.rs
+++ b/compiler/rustc_trait_selection/src/traits/util.rs
@@ -262,7 +262,7 @@ pub fn closure_trait_ref_and_return_type<'tcx>(
         TupleArgumentsFlag::No => sig.skip_binder().inputs()[0],
         TupleArgumentsFlag::Yes => tcx.mk_tup(sig.skip_binder().inputs()),
     };
-    let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty, arguments_tuple]);
+    let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty, arguments_tuple]);
     sig.map_bound(|sig| (trait_ref, sig.output()))
 }
 
@@ -273,7 +273,7 @@ pub fn generator_trait_ref_and_outputs<'tcx>(
     sig: ty::PolyGenSig<'tcx>,
 ) -> ty::Binder<'tcx, (ty::TraitRef<'tcx>, Ty<'tcx>, Ty<'tcx>)> {
     assert!(!self_ty.has_escaping_bound_vars());
-    let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty, sig.skip_binder().resume_ty]);
+    let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty, sig.skip_binder().resume_ty]);
     sig.map_bound(|sig| (trait_ref, sig.yield_ty, sig.return_ty))
 }
 
@@ -284,7 +284,7 @@ pub fn future_trait_ref_and_outputs<'tcx>(
     sig: ty::PolyGenSig<'tcx>,
 ) -> ty::Binder<'tcx, (ty::TraitRef<'tcx>, Ty<'tcx>)> {
     assert!(!self_ty.has_escaping_bound_vars());
-    let trait_ref = tcx.mk_trait_ref(fn_trait_def_id, [self_ty]);
+    let trait_ref = ty::TraitRef::new(tcx, fn_trait_def_id, [self_ty]);
     sig.map_bound(|sig| (trait_ref, sig.return_ty))
 }
 
diff --git a/compiler/rustc_trait_selection/src/traits/vtable.rs b/compiler/rustc_trait_selection/src/traits/vtable.rs
index c56e7c7cadd..f7a3126b4aa 100644
--- a/compiler/rustc_trait_selection/src/traits/vtable.rs
+++ b/compiler/rustc_trait_selection/src/traits/vtable.rs
@@ -359,7 +359,7 @@ pub(crate) fn vtable_trait_upcasting_coercion_new_vptr_slot<'tcx>(
     // this has been typecked-before, so diagnostics is not really needed.
     let unsize_trait_did = tcx.require_lang_item(LangItem::Unsize, None);
 
-    let trait_ref = tcx.mk_trait_ref(unsize_trait_did, [source, target]);
+    let trait_ref = ty::TraitRef::new(tcx, unsize_trait_did, [source, target]);
 
     match tcx.codegen_select_candidate((ty::ParamEnv::reveal_all(), ty::Binder::dummy(trait_ref))) {
         Ok(ImplSource::TraitUpcasting(implsrc_traitcasting)) => {
diff --git a/compiler/rustc_trait_selection/src/traits/wf.rs b/compiler/rustc_trait_selection/src/traits/wf.rs
index 0590e02d84a..22710c7c059 100644
--- a/compiler/rustc_trait_selection/src/traits/wf.rs
+++ b/compiler/rustc_trait_selection/src/traits/wf.rs
@@ -463,7 +463,8 @@ impl<'tcx> WfPredicates<'tcx> {
     fn require_sized(&mut self, subty: Ty<'tcx>, cause: traits::ObligationCauseCode<'tcx>) {
         if !subty.has_escaping_bound_vars() {
             let cause = self.cause(cause);
-            let trait_ref = self.tcx.at(cause.span).mk_trait_ref(LangItem::Sized, [subty]);
+            let trait_ref =
+                ty::TraitRef::from_lang_item(self.tcx, LangItem::Sized, cause.span, [subty]);
             self.out.push(traits::Obligation::with_depth(
                 self.tcx,
                 cause,