change usages of impl_trait_ref to bound_impl_trait_ref

compiler/rustc_hir_analysis/src/astconv/mod.rs

@@ -2059,14 +2059,14 @@ impl<'o, 'tcx> dyn AstConv<'tcx> + 'o {
             (_, Res::SelfTyAlias { alias_to: impl_def_id, is_trait_impl: true, .. }) => {
                 // `Self` in an impl of a trait -- we have a concrete self type and a
                 // trait reference.
-                let Some(trait_ref) = tcx.impl_trait_ref(impl_def_id) else {
+                let Some(trait_ref) = tcx.bound_impl_trait_ref(impl_def_id) else {
                     // A cycle error occurred, most likely.
                     let guar = tcx.sess.delay_span_bug(span, "expected cycle error");
                     return Err(guar);
                 };
 
                 self.one_bound_for_assoc_type(
-                    || traits::supertraits(tcx, ty::Binder::dummy(trait_ref)),
+                    || traits::supertraits(tcx, ty::Binder::dummy(trait_ref.skip_binder())),
                     || "Self".to_string(),
                     assoc_ident,
                     span,

compiler/rustc_hir_analysis/src/check/check.rs

@@ -535,12 +535,12 @@ fn check_item_type(tcx: TyCtxt<'_>, id: hir::ItemId) {
                 return;
             };
             debug!("ItemKind::Impl {} with id {:?}", it.ident, it.owner_id);
-            if let Some(impl_trait_ref) = tcx.impl_trait_ref(it.owner_id) {
+            if let Some(impl_trait_ref) = tcx.bound_impl_trait_ref(it.owner_id.to_def_id()) {
                 check_impl_items_against_trait(
                     tcx,
                     it.span,
                     it.owner_id.def_id,
-                    impl_trait_ref,
+                    impl_trait_ref.skip_binder(),
                     &impl_.items,
                 );
                 check_on_unimplemented(tcx, it);

compiler/rustc_hir_analysis/src/check/compare_impl_item.rs

@@ -616,7 +616,8 @@ pub(super) fn collect_return_position_impl_trait_in_trait_tys<'tcx>(
 ) -> Result<&'tcx FxHashMap<DefId, Ty<'tcx>>, ErrorGuaranteed> {
     let impl_m = tcx.opt_associated_item(def_id).unwrap();
     let trait_m = tcx.opt_associated_item(impl_m.trait_item_def_id.unwrap()).unwrap();
-    let impl_trait_ref = tcx.impl_trait_ref(impl_m.impl_container(tcx).unwrap()).unwrap();
+    let impl_trait_ref =
+        tcx.bound_impl_trait_ref(impl_m.impl_container(tcx).unwrap()).unwrap().subst_identity();
     let param_env = tcx.param_env(def_id);
 
     // First, check a few of the same things as `compare_impl_method`,
@@ -1684,7 +1685,8 @@ pub(super) fn compare_impl_const_raw(
 ) -> Result<(), ErrorGuaranteed> {
     let impl_const_item = tcx.associated_item(impl_const_item_def);
     let trait_const_item = tcx.associated_item(trait_const_item_def);
-    let impl_trait_ref = tcx.impl_trait_ref(impl_const_item.container_id(tcx)).unwrap();
+    let impl_trait_ref =
+        tcx.bound_impl_trait_ref(impl_const_item.container_id(tcx)).unwrap().subst_identity();
     debug!("compare_const_impl(impl_trait_ref={:?})", impl_trait_ref);
 
     let impl_c_span = tcx.def_span(impl_const_item_def.to_def_id());

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -181,8 +181,8 @@ fn check_item<'tcx>(tcx: TyCtxt<'tcx>, item: &'tcx hir::Item<'tcx>) {
         // for `T`
         hir::ItemKind::Impl(ref impl_) => {
             let is_auto = tcx
-                .impl_trait_ref(def_id)
+                .bound_impl_trait_ref(def_id.into())
-                .map_or(false, |trait_ref| tcx.trait_is_auto(trait_ref.def_id));
+                .map_or(false, |trait_ref| tcx.trait_is_auto(trait_ref.skip_binder().def_id));
             if let (hir::Defaultness::Default { .. }, true) = (impl_.defaultness, is_auto) {
                 let sp = impl_.of_trait.as_ref().map_or(item.span, |t| t.path.span);
                 let mut err =
@@ -1253,7 +1253,8 @@ fn check_impl<'tcx>(
                 // `#[rustc_reservation_impl]` impls are not real impls and
                 // therefore don't need to be WF (the trait's `Self: Trait` predicate
                 // won't hold).
-                let trait_ref = tcx.impl_trait_ref(item.owner_id).unwrap();
+                let trait_ref =
+                    tcx.bound_impl_trait_ref(item.owner_id.to_def_id()).unwrap().subst_identity();
                 let trait_ref = wfcx.normalize(
                     ast_trait_ref.path.span,
                     Some(WellFormedLoc::Ty(item.hir_id().expect_owner().def_id)),

compiler/rustc_hir_analysis/src/coherence/builtin.rs

@@ -192,7 +192,7 @@ fn visit_implementation_of_dispatch_from_dyn(tcx: TyCtxt<'_>, impl_did: LocalDef
     let source = tcx.type_of(impl_did);
     assert!(!source.has_escaping_bound_vars());
     let target = {
-        let trait_ref = tcx.impl_trait_ref(impl_did).unwrap();
+        let trait_ref = tcx.bound_impl_trait_ref(impl_did.into()).unwrap().subst_identity();
         assert_eq!(trait_ref.def_id, dispatch_from_dyn_trait);
 
         trait_ref.substs.type_at(1)
@@ -354,7 +354,7 @@ pub fn coerce_unsized_info<'tcx>(tcx: TyCtxt<'tcx>, impl_did: DefId) -> CoerceUn
     });
 
     let source = tcx.type_of(impl_did);
-    let trait_ref = tcx.impl_trait_ref(impl_did).unwrap();
+    let trait_ref = tcx.bound_impl_trait_ref(impl_did.into()).unwrap().subst_identity();
     assert_eq!(trait_ref.def_id, coerce_unsized_trait);
     let target = trait_ref.substs.type_at(1);
     debug!("visit_implementation_of_coerce_unsized: {:?} -> {:?} (bound)", source, target);

compiler/rustc_hir_analysis/src/coherence/mod.rs

@@ -128,7 +128,7 @@ fn coherent_trait(tcx: TyCtxt<'_>, def_id: DefId) {
 
     let impls = tcx.hir().trait_impls(def_id);
     for &impl_def_id in impls {
-        let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+        let trait_ref = tcx.bound_impl_trait_ref(impl_def_id.into()).unwrap().subst_identity();
 
         check_impl(tcx, impl_def_id, trait_ref);
         check_object_overlap(tcx, impl_def_id, trait_ref);

compiler/rustc_hir_analysis/src/coherence/orphan.rs

@@ -21,7 +21,7 @@ pub(crate) fn orphan_check_impl(
     tcx: TyCtxt<'_>,
     impl_def_id: LocalDefId,
 ) -> Result<(), ErrorGuaranteed> {
-    let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+    let trait_ref = tcx.bound_impl_trait_ref(impl_def_id.into()).unwrap().skip_binder();
     trait_ref.error_reported()?;
 
     let ret = do_orphan_check_impl(tcx, trait_ref, impl_def_id);

compiler/rustc_hir_analysis/src/coherence/unsafety.rs

@@ -13,7 +13,9 @@ pub(super) fn check_item(tcx: TyCtxt<'_>, def_id: LocalDefId) {
     let item = tcx.hir().expect_item(def_id);
     let hir::ItemKind::Impl(ref impl_) = item.kind else { bug!() };
 
-    if let Some(trait_ref) = tcx.impl_trait_ref(item.owner_id) {
+    if let Some(trait_ref) =
+        tcx.bound_impl_trait_ref(item.owner_id.to_def_id()).map(|t| t.subst_identity())
+    {
         let trait_def = tcx.trait_def(trait_ref.def_id);
         let unsafe_attr =
             impl_.generics.params.iter().find(|p| p.pure_wrt_drop).map(|_| "may_dangle");

compiler/rustc_hir_analysis/src/collect/predicates_of.rs

@@ -87,7 +87,9 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
         Node::Item(item) => match item.kind {
             ItemKind::Impl(ref impl_) => {
                 if impl_.defaultness.is_default() {
-                    is_default_impl_trait = tcx.impl_trait_ref(def_id).map(ty::Binder::dummy);
+                    is_default_impl_trait = tcx
+                        .bound_impl_trait_ref(def_id)
+                        .map(|t| ty::Binder::dummy(t.subst_identity()));
                 }
                 &impl_.generics
             }
@@ -251,7 +253,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: DefId) -> ty::GenericP
     // for details.
     if let Node::Item(&Item { kind: ItemKind::Impl { .. }, .. }) = node {
         let self_ty = tcx.type_of(def_id);
-        let trait_ref = tcx.impl_trait_ref(def_id);
+        let trait_ref = tcx.bound_impl_trait_ref(def_id).map(ty::EarlyBinder::subst_identity);
         cgp::setup_constraining_predicates(
             tcx,
             &mut predicates,

compiler/rustc_hir_analysis/src/collect/type_of.rs

@@ -286,7 +286,7 @@ pub(super) fn type_of(tcx: TyCtxt<'_>, def_id: DefId) -> Ty<'_> {
                 }
             }
             ImplItemKind::Type(ty) => {
-                if tcx.impl_trait_ref(tcx.hir().get_parent_item(hir_id)).is_none() {
+                if tcx.bound_impl_trait_ref(tcx.hir().get_parent_item(hir_id).to_def_id()).is_none() {
                     check_feature_inherent_assoc_ty(tcx, item.span);
                 }
 

compiler/rustc_hir_analysis/src/impl_wf_check.rs

@@ -85,7 +85,8 @@ fn enforce_impl_params_are_constrained(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
     }
     let impl_generics = tcx.generics_of(impl_def_id);
     let impl_predicates = tcx.predicates_of(impl_def_id);
-    let impl_trait_ref = tcx.impl_trait_ref(impl_def_id);
+    let impl_trait_ref =
+        tcx.bound_impl_trait_ref(impl_def_id.into()).map(ty::EarlyBinder::subst_identity);
 
     let mut input_parameters = cgp::parameters_for_impl(impl_self_ty, impl_trait_ref);
     cgp::identify_constrained_generic_params(

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -89,8 +89,8 @@ pub(super) fn check_min_specialization(tcx: TyCtxt<'_>, impl_def_id: LocalDefId)
 }
 
 fn parent_specialization_node(tcx: TyCtxt<'_>, impl1_def_id: LocalDefId) -> Option<Node> {
-    let trait_ref = tcx.impl_trait_ref(impl1_def_id)?;
+    let trait_ref = tcx.bound_impl_trait_ref(impl1_def_id.into())?;
-    let trait_def = tcx.trait_def(trait_ref.def_id);
+    let trait_def = tcx.trait_def(trait_ref.skip_binder().def_id);
 
     let impl2_node = trait_def.ancestors(tcx, impl1_def_id.to_def_id()).ok()?.nth(1)?;
 
@@ -207,7 +207,7 @@ fn unconstrained_parent_impl_substs<'tcx>(
     let impl_generic_predicates = tcx.predicates_of(impl_def_id);
     let mut unconstrained_parameters = FxHashSet::default();
     let mut constrained_params = FxHashSet::default();
-    let impl_trait_ref = tcx.impl_trait_ref(impl_def_id);
+    let impl_trait_ref = tcx.bound_impl_trait_ref(impl_def_id).map(ty::EarlyBinder::subst_identity);
 
     // Unfortunately the functions in `constrained_generic_parameters` don't do
     // what we want here. We want only a list of constrained parameters while
@@ -370,7 +370,7 @@ fn check_predicates<'tcx>(
     });
 
     // Include the well-formed predicates of the type parameters of the impl.
-    for arg in tcx.impl_trait_ref(impl1_def_id).unwrap().substs {
+    for arg in tcx.bound_impl_trait_ref(impl1_def_id.into()).unwrap().subst_identity().substs {
         let infcx = &tcx.infer_ctxt().build();
         let obligations = wf::obligations(
             infcx,

compiler/rustc_hir_typeck/src/method/confirm.rs

@@ -240,7 +240,7 @@ impl<'a, 'tcx> ConfirmContext<'a, 'tcx> {
             probe::InherentImplPick => {
                 let impl_def_id = pick.item.container_id(self.tcx);
                 assert!(
-                    self.tcx.impl_trait_ref(impl_def_id).is_none(),
+                    self.tcx.bound_impl_trait_ref(impl_def_id).is_none(),
                     "impl {:?} is not an inherent impl",
                     impl_def_id
                 );

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -1036,8 +1036,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     // Provide the best span we can. Use the item, if local to crate, else
                     // the impl, if local to crate (item may be defaulted), else nothing.
                     let Some(item) = self.associated_value(impl_did, item_name).or_else(|| {
-                        let impl_trait_ref = self.tcx.impl_trait_ref(impl_did)?;
+                        let impl_trait_ref = self.tcx.bound_impl_trait_ref(impl_did)?;
-                        self.associated_value(impl_trait_ref.def_id, item_name)
+                        self.associated_value(impl_trait_ref.skip_binder().def_id, item_name)
                     }) else {
                         continue;
                     };
@@ -1052,10 +1052,13 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     let impl_ty = self.tcx.at(span).type_of(impl_did);
 
-                    let insertion = match self.tcx.impl_trait_ref(impl_did) {
+                    let insertion = match self.tcx.bound_impl_trait_ref(impl_did) {
                         None => String::new(),
                         Some(trait_ref) => {
-                            format!(" of the trait `{}`", self.tcx.def_path_str(trait_ref.def_id))
+                            format!(
+                                " of the trait `{}`",
+                                self.tcx.def_path_str(trait_ref.skip_binder().def_id)
+                            )
                         }
                     };
 
@@ -1085,8 +1088,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                         err.note(&note_str);
                     }
                     if let Some(sugg_span) = sugg_span
-                        && let Some(trait_ref) = self.tcx.impl_trait_ref(impl_did) {
+                        && let Some(trait_ref) = self.tcx.bound_impl_trait_ref(impl_did) {
-                        let path = self.tcx.def_path_str(trait_ref.def_id);
+                        let path = self.tcx.def_path_str(trait_ref.skip_binder().def_id);
 
                         let ty = match item.kind {
                             ty::AssocKind::Const | ty::AssocKind::Type => rcvr_ty,
@@ -2581,7 +2584,8 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                             self.tcx.impl_polarity(*imp_did) == ty::ImplPolarity::Negative
                         })
                         .any(|imp_did| {
-                            let imp = self.tcx.impl_trait_ref(imp_did).unwrap();
+                            let imp =
+                                self.tcx.bound_impl_trait_ref(imp_did).unwrap().subst_identity();
                             let imp_simp =
                                 simplify_type(self.tcx, imp.self_ty(), TreatParams::AsPlaceholder);
                             imp_simp.map_or(false, |s| s == simp_rcvr_ty)

compiler/rustc_infer/src/infer/error_reporting/note.rs

@@ -317,9 +317,10 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
             self.tcx.associated_item(impl_item_def_id).impl_container(self.tcx) else { return; };
         let Some(trait_ref) = self
             .tcx
-            .impl_trait_ref(impl_def_id)
+            .bound_impl_trait_ref(impl_def_id)
             else { return; };
         let trait_substs = trait_ref
+            .subst_identity()
             // Replace the explicit self type with `Self` for better suggestion rendering
             .with_self_ty(self.tcx, self.tcx.mk_ty_param(0, kw::SelfUpper))
             .substs;

compiler/rustc_lint/src/nonstandard_style.rs

@@ -26,7 +26,7 @@ pub fn method_context(cx: &LateContext<'_>, id: hir::HirId) -> MethodLateContext
     let item = cx.tcx.associated_item(def_id);
     match item.container {
         ty::TraitContainer => MethodLateContext::TraitAutoImpl,
-        ty::ImplContainer => match cx.tcx.impl_trait_ref(item.container_id(cx.tcx)) {
+        ty::ImplContainer => match cx.tcx.bound_impl_trait_ref(item.container_id(cx.tcx)) {
             Some(_) => MethodLateContext::TraitImpl,
             None => MethodLateContext::PlainImpl,
         },

compiler/rustc_lint/src/pass_by_value.rs

@@ -24,7 +24,7 @@ impl<'tcx> LateLintPass<'tcx> for PassByValue {
         match &ty.kind {
             TyKind::Ref(_, hir::MutTy { ty: inner_ty, mutbl: hir::Mutability::Not }) => {
                 if let Some(impl_did) = cx.tcx.impl_of_method(ty.hir_id.owner.to_def_id()) {
-                    if cx.tcx.impl_trait_ref(impl_did).is_some() {
+                    if cx.tcx.bound_impl_trait_ref(impl_did).is_some() {
                         return;
                     }
                 }

compiler/rustc_metadata/src/rmeta/encoder.rs

@@ -1555,7 +1555,8 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                 self.tables.impl_defaultness.set(def_id.index, *defaultness);
                 self.tables.constness.set(def_id.index, *constness);
 
-                let trait_ref = self.tcx.impl_trait_ref(def_id);
+                let trait_ref =
+                    self.tcx.bound_impl_trait_ref(def_id).map(ty::EarlyBinder::skip_binder);
                 if let Some(trait_ref) = trait_ref {
                     let trait_def = self.tcx.trait_def(trait_ref.def_id);
                     if let Ok(mut an) = trait_def.ancestors(self.tcx, def_id) {
@@ -1632,7 +1633,9 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
             }
         }
         if let hir::ItemKind::Impl { .. } = item.kind {
-            if let Some(trait_ref) = self.tcx.impl_trait_ref(def_id) {
+            if let Some(trait_ref) =
+                self.tcx.bound_impl_trait_ref(def_id).map(ty::EarlyBinder::subst_identity)
+            {
                 record!(self.tables.impl_trait_ref[def_id] <- trait_ref);
             }
         }
@@ -1898,7 +1901,10 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
 
         for id in tcx.hir().items() {
             if matches!(tcx.def_kind(id.owner_id), DefKind::Impl) {
-                if let Some(trait_ref) = tcx.impl_trait_ref(id.owner_id) {
+                if let Some(trait_ref) = tcx
+                    .bound_impl_trait_ref(id.owner_id.to_def_id())
+                    .map(ty::EarlyBinder::subst_identity)
+                {
                     let simplified_self_ty = fast_reject::simplify_type(
                         self.tcx,
                         trait_ref.self_ty(),

compiler/rustc_middle/src/hir/mod.rs

@@ -101,7 +101,8 @@ impl<'tcx> TyCtxt<'tcx> {
     }
 
     pub fn impl_subject(self, def_id: DefId) -> ImplSubject<'tcx> {
-        self.impl_trait_ref(def_id)
+        self.bound_impl_trait_ref(def_id)
+            .map(|t| t.subst_identity())
             .map(ImplSubject::Trait)
             .unwrap_or_else(|| ImplSubject::Inherent(self.type_of(def_id)))
     }

compiler/rustc_middle/src/ty/context.rs

@@ -1027,7 +1027,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Checks if the bound region is in Impl Item.
     pub fn is_bound_region_in_impl_item(self, suitable_region_binding_scope: LocalDefId) -> bool {
         let container_id = self.parent(suitable_region_binding_scope.to_def_id());
-        if self.impl_trait_ref(container_id).is_some() {
+        if self.bound_impl_trait_ref(container_id).is_some() {
             // For now, we do not try to target impls of traits. This is
             // because this message is going to suggest that the user
             // change the fn signature, but they may not be free to do so,

compiler/rustc_middle/src/ty/mod.rs

@@ -2187,8 +2187,12 @@ impl<'tcx> TyCtxt<'tcx> {
     ) -> Option<ImplOverlapKind> {
         // If either trait impl references an error, they're allowed to overlap,
         // as one of them essentially doesn't exist.
-        if self.impl_trait_ref(def_id1).map_or(false, |tr| tr.references_error())
+        if self
-            || self.impl_trait_ref(def_id2).map_or(false, |tr| tr.references_error())
+            .bound_impl_trait_ref(def_id1)
+            .map_or(false, |tr| tr.skip_binder().references_error())
+            || self
+                .bound_impl_trait_ref(def_id2)
+                .map_or(false, |tr| tr.skip_binder().references_error())
         {
             return Some(ImplOverlapKind::Permitted { marker: false });
         }
@@ -2217,8 +2221,8 @@ impl<'tcx> TyCtxt<'tcx> {
 
         let is_marker_overlap = {
             let is_marker_impl = |def_id: DefId| -> bool {
-                let trait_ref = self.impl_trait_ref(def_id);
+                let trait_ref = self.bound_impl_trait_ref(def_id);
-                trait_ref.map_or(false, |tr| self.trait_def(tr.def_id).is_marker)
+                trait_ref.map_or(false, |tr| self.trait_def(tr.skip_binder().def_id).is_marker)
             };
             is_marker_impl(def_id1) && is_marker_impl(def_id2)
         };
@@ -2364,7 +2368,7 @@ impl<'tcx> TyCtxt<'tcx> {
     /// Given the `DefId` of an impl, returns the `DefId` of the trait it implements.
     /// If it implements no trait, returns `None`.
     pub fn trait_id_of_impl(self, def_id: DefId) -> Option<DefId> {
-        self.impl_trait_ref(def_id).map(|tr| tr.def_id)
+        self.bound_impl_trait_ref(def_id).map(|tr| tr.skip_binder().def_id)
     }
 
     /// If the given `DefId` describes an item belonging to a trait,

compiler/rustc_monomorphize/src/collector.rs

@@ -1351,7 +1351,10 @@ fn create_mono_items_for_default_impls<'tcx>(
                 tcx.def_path_str(item.owner_id.to_def_id())
             );
 
-            if let Some(trait_ref) = tcx.impl_trait_ref(item.owner_id) {
+            if let Some(trait_ref) = tcx
+                .bound_impl_trait_ref(item.owner_id.to_def_id())
+                .map(ty::EarlyBinder::subst_identity)
+            {
                 let param_env = ty::ParamEnv::reveal_all();
                 let trait_ref = tcx.normalize_erasing_regions(param_env, trait_ref);
                 let overridden_methods = tcx.impl_item_implementor_ids(item.owner_id);

compiler/rustc_passes/src/dead.rs

@@ -266,7 +266,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
             if let Some(trait_of) = self.tcx.trait_id_of_impl(impl_of)
                 && self.tcx.has_attr(trait_of, sym::rustc_trivial_field_reads)
             {
-                let trait_ref = self.tcx.impl_trait_ref(impl_of).unwrap();
+                let trait_ref = self.tcx.bound_impl_trait_ref(impl_of).unwrap().subst_identity();
                 if let ty::Adt(adt_def, _) = trait_ref.self_ty().kind()
                     && let Some(adt_def_id) = adt_def.did().as_local()
                 {
@@ -310,7 +310,7 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
             }
             Node::ImplItem(impl_item) => {
                 let item = self.tcx.local_parent(impl_item.owner_id.def_id);
-                if self.tcx.impl_trait_ref(item).is_none() {
+                if self.tcx.bound_impl_trait_ref(item.into()).is_none() {
                     //// If it's a type whose items are live, then it's live, too.
                     //// This is done to handle the case where, for example, the static
                     //// method of a private type is used, but the type itself is never
@@ -534,7 +534,7 @@ fn check_item<'tcx>(
             }
         }
         DefKind::Impl => {
-            let of_trait = tcx.impl_trait_ref(id.owner_id);
+            let of_trait = tcx.bound_impl_trait_ref(id.owner_id.to_def_id());
 
             if of_trait.is_some() {
                 worklist.push(id.owner_id.def_id);

compiler/rustc_passes/src/stability.rs

@@ -593,7 +593,7 @@ impl<'tcx> Visitor<'tcx> for MissingStabilityAnnotations<'tcx> {
 
     fn visit_impl_item(&mut self, ii: &'tcx hir::ImplItem<'tcx>) {
         let impl_def_id = self.tcx.hir().get_parent_item(ii.hir_id());
-        if self.tcx.impl_trait_ref(impl_def_id).is_none() {
+        if self.tcx.bound_impl_trait_ref(impl_def_id.to_def_id()).is_none() {
             self.check_missing_stability(ii.owner_id.def_id, ii.span);
             self.check_missing_const_stability(ii.owner_id.def_id, ii.span);
         }

compiler/rustc_privacy/src/lib.rs

@@ -337,8 +337,8 @@ trait VisibilityLike: Sized {
     ) -> Self {
         let mut find = FindMin { tcx, effective_visibilities, min: Self::MAX };
         find.visit(tcx.type_of(def_id));
-        if let Some(trait_ref) = tcx.impl_trait_ref(def_id) {
+        if let Some(trait_ref) = tcx.bound_impl_trait_ref(def_id.into()) {
-            find.visit_trait(trait_ref);
+            find.visit_trait(trait_ref.subst_identity());
         }
         find.min
     }
@@ -857,8 +857,8 @@ impl ReachEverythingInTheInterfaceVisitor<'_, '_> {
     }
 
     fn trait_ref(&mut self) -> &mut Self {
-        if let Some(trait_ref) = self.ev.tcx.impl_trait_ref(self.item_def_id) {
+        if let Some(trait_ref) = self.ev.tcx.bound_impl_trait_ref(self.item_def_id.into()) {
-            self.visit_trait(trait_ref);
+            self.visit_trait(trait_ref.subst_identity());
         }
         self
     }

compiler/rustc_trait_selection/src/traits/coherence.rs

@@ -77,8 +77,8 @@ pub fn overlapping_impls(
     // a quick check via fast_reject to tell if the impl headers could possibly
     // unify.
     let drcx = DeepRejectCtxt { treat_obligation_params: TreatParams::AsInfer };
-    let impl1_ref = tcx.impl_trait_ref(impl1_def_id);
+    let impl1_ref = tcx.bound_impl_trait_ref(impl1_def_id).map(ty::EarlyBinder::subst_identity);
-    let impl2_ref = tcx.impl_trait_ref(impl2_def_id);
+    let impl2_ref = tcx.bound_impl_trait_ref(impl2_def_id).map(ty::EarlyBinder::subst_identity);
     let may_overlap = match (impl1_ref, impl2_ref) {
         (Some(a), Some(b)) => iter::zip(a.substs, b.substs)
             .all(|(arg1, arg2)| drcx.generic_args_may_unify(arg1, arg2)),
@@ -461,7 +461,7 @@ pub fn orphan_check(tcx: TyCtxt<'_>, impl_def_id: DefId) -> Result<(), OrphanChe
 
     // We only except this routine to be invoked on implementations
     // of a trait, not inherent implementations.
-    let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+    let trait_ref = tcx.bound_impl_trait_ref(impl_def_id).unwrap().skip_binder();
     debug!("orphan_check: trait_ref={:?}", trait_ref);
 
     // If the *trait* is local to the crate, ok.

compiler/rustc_trait_selection/src/traits/error_reporting/mod.rs

@@ -1940,7 +1940,7 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     return None;
                 }
 
-                let imp = self.tcx.impl_trait_ref(def_id).unwrap();
+                let imp = self.tcx.bound_impl_trait_ref(def_id).unwrap().subst_identity();
 
                 self.fuzzy_match_tys(trait_pred.skip_binder().self_ty(), imp.self_ty(), false)
                     .map(|similarity| ImplCandidate { trait_ref: imp, similarity })
@@ -2039,7 +2039,8 @@ impl<'tcx> InferCtxtPrivExt<'tcx> for TypeErrCtxt<'_, 'tcx> {
                     self.tcx.impl_polarity(def_id) != ty::ImplPolarity::Negative
                         || self.tcx.is_builtin_derive(def_id)
                 })
-                .filter_map(|def_id| self.tcx.impl_trait_ref(def_id))
+                .filter_map(|def_id| self.tcx.bound_impl_trait_ref(def_id))
+                .map(ty::EarlyBinder::subst_identity)
                 .filter(|trait_ref| {
                     let self_ty = trait_ref.self_ty();
                     // Avoid mentioning type parameters.

compiler/rustc_trait_selection/src/traits/mod.rs

@@ -521,8 +521,10 @@ fn is_impossible_method(tcx: TyCtxt<'_>, (impl_def_id, trait_item_def_id): (DefI
 
     let generics = tcx.generics_of(trait_item_def_id);
     let predicates = tcx.predicates_of(trait_item_def_id);
-    let impl_trait_ref =
+    let impl_trait_ref = tcx
-        tcx.impl_trait_ref(impl_def_id).expect("expected impl to correspond to trait");
+        .bound_impl_trait_ref(impl_def_id)
+        .expect("expected impl to correspond to trait")
+        .subst_identity();
     let param_env = tcx.param_env(impl_def_id);
 
     let mut visitor = ReferencesOnlyParentGenerics { tcx, generics, trait_item_def_id };

compiler/rustc_trait_selection/src/traits/specialize/mod.rs

@@ -148,7 +148,7 @@ pub(super) fn specializes(tcx: TyCtxt<'_>, (impl1_def_id, impl2_def_id): (DefId,
 
     // create a parameter environment corresponding to a (placeholder) instantiation of impl1
     let penv = tcx.param_env(impl1_def_id);
-    let impl1_trait_ref = tcx.impl_trait_ref(impl1_def_id).unwrap();
+    let impl1_trait_ref = tcx.bound_impl_trait_ref(impl1_def_id).unwrap().subst_identity();
 
     // Create an infcx, taking the predicates of impl1 as assumptions:
     let infcx = tcx.infer_ctxt().build();
@@ -431,7 +431,7 @@ fn report_conflicting_impls<'tcx>(
 pub(crate) fn to_pretty_impl_header(tcx: TyCtxt<'_>, impl_def_id: DefId) -> Option<String> {
     use std::fmt::Write;
 
-    let trait_ref = tcx.impl_trait_ref(impl_def_id)?;
+    let trait_ref = tcx.bound_impl_trait_ref(impl_def_id)?.skip_binder();
     let mut w = "impl".to_owned();
 
     let substs = InternalSubsts::identity_for_item(tcx, impl_def_id);

compiler/rustc_trait_selection/src/traits/specialize/specialization_graph.rs

@@ -48,7 +48,7 @@ trait ChildrenExt<'tcx> {
 impl<'tcx> ChildrenExt<'tcx> for Children {
     /// Insert an impl into this set of children without comparing to any existing impls.
     fn insert_blindly(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId) {
-        let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+        let trait_ref = tcx.bound_impl_trait_ref(impl_def_id).unwrap().subst_identity();
         if let Some(st) = fast_reject::simplify_type(tcx, trait_ref.self_ty(), TreatParams::AsInfer)
         {
             debug!("insert_blindly: impl_def_id={:?} st={:?}", impl_def_id, st);
@@ -63,7 +63,7 @@ impl<'tcx> ChildrenExt<'tcx> for Children {
     /// an impl with a parent. The impl must be present in the list of
     /// children already.
     fn remove_existing(&mut self, tcx: TyCtxt<'tcx>, impl_def_id: DefId) {
-        let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+        let trait_ref = tcx.bound_impl_trait_ref(impl_def_id).unwrap().subst_identity();
         let vec: &mut Vec<DefId>;
         if let Some(st) = fast_reject::simplify_type(tcx, trait_ref.self_ty(), TreatParams::AsInfer)
         {
@@ -181,7 +181,7 @@ impl<'tcx> ChildrenExt<'tcx> for Children {
             if le && !ge {
                 debug!(
                     "descending as child of TraitRef {:?}",
-                    tcx.impl_trait_ref(possible_sibling).unwrap()
+                    tcx.bound_impl_trait_ref(possible_sibling).unwrap().subst_identity()
                 );
 
                 // The impl specializes `possible_sibling`.
@@ -189,7 +189,7 @@ impl<'tcx> ChildrenExt<'tcx> for Children {
             } else if ge && !le {
                 debug!(
                     "placing as parent of TraitRef {:?}",
-                    tcx.impl_trait_ref(possible_sibling).unwrap()
+                    tcx.bound_impl_trait_ref(possible_sibling).unwrap().subst_identity()
                 );
 
                 replace_children.push(possible_sibling);
@@ -275,7 +275,7 @@ impl<'tcx> GraphExt<'tcx> for Graph {
     ) -> Result<Option<FutureCompatOverlapError<'tcx>>, OverlapError<'tcx>> {
         assert!(impl_def_id.is_local());
 
-        let trait_ref = tcx.impl_trait_ref(impl_def_id).unwrap();
+        let trait_ref = tcx.bound_impl_trait_ref(impl_def_id).unwrap().subst_identity();
         let trait_def_id = trait_ref.def_id;
 
         debug!(
@@ -388,7 +388,7 @@ pub(crate) fn assoc_def(
     impl_def_id: DefId,
     assoc_def_id: DefId,
 ) -> Result<LeafDef, ErrorGuaranteed> {
-    let trait_def_id = tcx.impl_trait_ref(impl_def_id).unwrap().def_id;
+    let trait_def_id = tcx.bound_impl_trait_ref(impl_def_id).unwrap().skip_binder().def_id;
     let trait_def = tcx.trait_def(trait_def_id);
 
     // This function may be called while we are still building the

compiler/rustc_traits/src/chalk/db.rs

@@ -380,7 +380,8 @@ impl<'tcx> chalk_solve::RustIrDatabase<RustInterner<'tcx>> for RustIrDatabase<'t
         let trait_def_id = auto_trait_id.0;
         let all_impls = self.interner.tcx.all_impls(trait_def_id);
         for impl_def_id in all_impls {
-            let trait_ref = self.interner.tcx.impl_trait_ref(impl_def_id).unwrap();
+            let trait_ref =
+                self.interner.tcx.bound_impl_trait_ref(impl_def_id).unwrap().subst_identity();
             let self_ty = trait_ref.self_ty();
             let provides = match (self_ty.kind(), chalk_ty) {
                 (&ty::Adt(impl_adt_def, ..), Adt(id, ..)) => impl_adt_def.did() == id.0.did(),

compiler/rustc_ty_utils/src/implied_bounds.rs

@@ -21,14 +21,16 @@ fn assumed_wf_types(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Ty<'_>> {
             assumed_wf_types.extend(liberated_sig.inputs_and_output);
             tcx.intern_type_list(&assumed_wf_types)
         }
-        DefKind::Impl => match tcx.impl_trait_ref(def_id) {
+        DefKind::Impl => {
+            match tcx.bound_impl_trait_ref(def_id).map(ty::EarlyBinder::subst_identity) {
                 Some(trait_ref) => {
                     let types: Vec<_> = trait_ref.substs.types().collect();
                     tcx.intern_type_list(&types)
                 }
                 // Only the impl self type
                 None => tcx.intern_type_list(&[tcx.type_of(def_id)]),
-        },
+            }
+        }
         DefKind::AssocConst | DefKind::AssocTy => tcx.assumed_wf_types(tcx.parent(def_id)),
         DefKind::Mod
         | DefKind::Struct

compiler/rustc_ty_utils/src/ty.rs

@@ -289,7 +289,7 @@ fn well_formed_types_in_env(tcx: TyCtxt<'_>, def_id: DefId) -> &ty::List<Predica
         // In a trait impl, we assume that the header trait ref and all its
         // constituents are well-formed.
         NodeKind::TraitImpl => {
-            let trait_ref = tcx.impl_trait_ref(def_id).expect("not an impl");
+            let trait_ref = tcx.bound_impl_trait_ref(def_id).expect("not an impl").subst_identity();
 
             // FIXME(chalk): this has problems because of late-bound regions
             //inputs.extend(trait_ref.substs.iter().flat_map(|arg| arg.walk()));
@@ -359,8 +359,9 @@ fn issue33140_self_ty(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Ty<'_>> {
     debug!("issue33140_self_ty({:?})", def_id);
 
     let trait_ref = tcx
-        .impl_trait_ref(def_id)
+        .bound_impl_trait_ref(def_id)
-        .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id));
+        .unwrap_or_else(|| bug!("issue33140_self_ty called on inherent impl {:?}", def_id))
+        .skip_binder();
 
     debug!("issue33140_self_ty({:?}), trait-ref={:?}", def_id, trait_ref);
 

src/librustdoc/clean/inline.rs

@@ -376,7 +376,7 @@ pub(crate) fn build_impl(
     let _prof_timer = cx.tcx.sess.prof.generic_activity("build_impl");
 
     let tcx = cx.tcx;
-    let associated_trait = tcx.impl_trait_ref(did);
+    let associated_trait = tcx.bound_impl_trait_ref(did).map(ty::EarlyBinder::skip_binder);
 
     // Only inline impl if the implemented trait is
     // reachable in rustdoc generated documentation

src/librustdoc/clean/types.rs

@@ -734,7 +734,7 @@ impl Item {
                     ty::ImplContainer => {
                         // Trait impl items always inherit the impl's visibility --
                         // we don't want to show `pub`.
-                        tcx.impl_trait_ref(tcx.parent(assoc_item.def_id)).is_some()
+                        tcx.bound_impl_trait_ref(tcx.parent(assoc_item.def_id)).is_some()
                     }
                 };
                 if is_trait_item {

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -784,9 +784,9 @@ fn trait_impls_for<'a>(
 
         // Look at each trait implementation to see if it's an impl for `did`
         tcx.find_map_relevant_impl(trait_, ty, |impl_| {
-            let trait_ref = tcx.impl_trait_ref(impl_).expect("this is not an inherent impl");
+            let trait_ref = tcx.bound_impl_trait_ref(impl_).expect("this is not an inherent impl");
             // Check if these are the same type.
-            let impl_type = trait_ref.self_ty();
+            let impl_type = trait_ref.subst_identity().self_ty();
             trace!(
                 "comparing type {} with kind {:?} against type {:?}",
                 impl_type,

src/tools/clippy/clippy_lints/src/derive.rs

@@ -247,11 +247,11 @@ fn check_hash_peq<'tcx>(
                     return;
                 }
 
-                let trait_ref = cx.tcx.impl_trait_ref(impl_id).expect("must be a trait implementation");
+                let trait_ref = cx.tcx.bound_impl_trait_ref(impl_id).expect("must be a trait implementation");
 
                 // Only care about `impl PartialEq<Foo> for Foo`
                 // For `impl PartialEq<B> for A, input_types is [A, B]
-                if trait_ref.substs.type_at(1) == ty {
+                if trait_ref.subst_identity().substs.type_at(1) == ty {
                     span_lint_and_then(
                         cx,
                         DERIVED_HASH_WITH_MANUAL_EQ,
@@ -295,11 +295,11 @@ fn check_ord_partial_ord<'tcx>(
                     return;
                 }
 
-                let trait_ref = cx.tcx.impl_trait_ref(impl_id).expect("must be a trait implementation");
+                let trait_ref = cx.tcx.bound_impl_trait_ref(impl_id).expect("must be a trait implementation");
 
                 // Only care about `impl PartialOrd<Foo> for Foo`
                 // For `impl PartialOrd<B> for A, input_types is [A, B]
-                if trait_ref.substs.type_at(1) == ty {
+                if trait_ref.subst_identity().substs.type_at(1) == ty {
                     let mess = if partial_ord_is_automatically_derived {
                         "you are implementing `Ord` explicitly but have derived `PartialOrd`"
                     } else {

src/tools/clippy/clippy_lints/src/fallible_impl_from.rs

@@ -55,8 +55,8 @@ impl<'tcx> LateLintPass<'tcx> for FallibleImplFrom {
         // check for `impl From<???> for ..`
         if_chain! {
             if let hir::ItemKind::Impl(impl_) = &item.kind;
-            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id);
+            if let Some(impl_trait_ref) = cx.tcx.bound_impl_trait_ref(item.owner_id.to_def_id());
-            if cx.tcx.is_diagnostic_item(sym::From, impl_trait_ref.def_id);
+            if cx.tcx.is_diagnostic_item(sym::From, impl_trait_ref.skip_binder().def_id);
             then {
                 lint_impl_body(cx, item.span, impl_.items);
             }

src/tools/clippy/clippy_lints/src/from_over_into.rs

@@ -76,7 +76,7 @@ impl<'tcx> LateLintPass<'tcx> for FromOverInto {
             && let Some(into_trait_seg) = hir_trait_ref.path.segments.last()
             // `impl Into<target_ty> for self_ty`
             && let Some(GenericArgs { args: [GenericArg::Type(target_ty)], .. }) = into_trait_seg.args
-            && let Some(middle_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id)
+            && let Some(middle_trait_ref) = cx.tcx.bound_impl_trait_ref(item.owner_id.to_def_id()).map(ty::EarlyBinder::subst_identity)
             && cx.tcx.is_diagnostic_item(sym::Into, middle_trait_ref.def_id)
             && !matches!(middle_trait_ref.substs.type_at(1).kind(), ty::Alias(ty::Opaque, _))
         {

src/tools/clippy/clippy_lints/src/implicit_saturating_sub.rs

@@ -101,7 +101,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingSub {
                             if name.ident.as_str() == "MIN";
                             if let Some(const_id) = cx.typeck_results().type_dependent_def_id(cond_num_val.hir_id);
                             if let Some(impl_id) = cx.tcx.impl_of_method(const_id);
-                            if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
+                            if let None = cx.tcx.bound_impl_trait_ref(impl_id); // An inherent impl
                             if cx.tcx.type_of(impl_id).is_integral();
                             then {
                                 print_lint_and_sugg(cx, var_name, expr)
@@ -114,7 +114,7 @@ impl<'tcx> LateLintPass<'tcx> for ImplicitSaturatingSub {
                             if name.ident.as_str() == "min_value";
                             if let Some(func_id) = cx.typeck_results().type_dependent_def_id(func.hir_id);
                             if let Some(impl_id) = cx.tcx.impl_of_method(func_id);
-                            if let None = cx.tcx.impl_trait_ref(impl_id); // An inherent impl
+                            if let None = cx.tcx.bound_impl_trait_ref(impl_id); // An inherent impl
                             if cx.tcx.type_of(impl_id).is_integral();
                             then {
                                 print_lint_and_sugg(cx, var_name, expr)

src/tools/clippy/clippy_lints/src/methods/implicit_clone.rs

@@ -53,7 +53,7 @@ pub fn is_clone_like(cx: &LateContext<'_>, method_name: &str, method_def_id: hir
         "to_vec" => cx
             .tcx
             .impl_of_method(method_def_id)
-            .filter(|&impl_did| cx.tcx.type_of(impl_did).is_slice() && cx.tcx.impl_trait_ref(impl_did).is_none())
+            .filter(|&impl_did| cx.tcx.type_of(impl_did).is_slice() && cx.tcx.bound_impl_trait_ref(impl_did).is_none())
             .is_some(),
         _ => false,
     }

src/tools/clippy/clippy_lints/src/methods/suspicious_splitn.rs

@@ -12,7 +12,7 @@ pub(super) fn check(cx: &LateContext<'_>, method_name: &str, expr: &Expr<'_>, se
         if count <= 1;
         if let Some(call_id) = cx.typeck_results().type_dependent_def_id(expr.hir_id);
         if let Some(impl_id) = cx.tcx.impl_of_method(call_id);
-        if cx.tcx.impl_trait_ref(impl_id).is_none();
+        if cx.tcx.bound_impl_trait_ref(impl_id).is_none();
         let self_ty = cx.tcx.type_of(impl_id);
         if self_ty.is_slice() || self_ty.is_str();
         then {

src/tools/clippy/clippy_lints/src/missing_doc.rs

@@ -175,7 +175,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingDoc {
     fn check_impl_item(&mut self, cx: &LateContext<'tcx>, impl_item: &'tcx hir::ImplItem<'_>) {
         // If the method is an impl for a trait, don't doc.
         if let Some(cid) = cx.tcx.associated_item(impl_item.owner_id).impl_container(cx.tcx) {
-            if cx.tcx.impl_trait_ref(cid).is_some() {
+            if cx.tcx.bound_impl_trait_ref(cid).is_some() {
                 return;
             }
         } else {

src/tools/clippy/clippy_lints/src/missing_inline.rs

@@ -155,7 +155,7 @@ impl<'tcx> LateLintPass<'tcx> for MissingInline {
         let container_id = assoc_item.container_id(cx.tcx);
         let trait_def_id = match assoc_item.container {
             TraitContainer => Some(container_id),
-            ImplContainer => cx.tcx.impl_trait_ref(container_id).map(|t| t.def_id),
+            ImplContainer => cx.tcx.bound_impl_trait_ref(container_id).map(|t| t.skip_binder().def_id),
         };
 
         if let Some(trait_def_id) = trait_def_id {

src/tools/clippy/clippy_lints/src/non_send_fields_in_send_ty.rs

@@ -89,8 +89,8 @@ impl<'tcx> LateLintPass<'tcx> for NonSendFieldInSendTy {
             if let Some(trait_id) = trait_ref.trait_def_id();
             if send_trait == trait_id;
             if hir_impl.polarity == ImplPolarity::Positive;
-            if let Some(ty_trait_ref) = cx.tcx.impl_trait_ref(item.owner_id);
+            if let Some(ty_trait_ref) = cx.tcx.bound_impl_trait_ref(item.owner_id.to_def_id());
-            if let self_ty = ty_trait_ref.self_ty();
+            if let self_ty = ty_trait_ref.subst_identity().self_ty();
             if let ty::Adt(adt_def, impl_trait_substs) = self_ty.kind();
             then {
                 let mut non_send_fields = Vec::new();

src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs

@@ -244,7 +244,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
             })) => {
                 #[allow(trivial_casts)]
                 if let Some(Node::Item(item)) = get_parent_node(cx.tcx, owner_id.into())
-                    && let Some(trait_ref) = cx.tcx.impl_trait_ref(item.owner_id)
+                    && let Some(trait_ref) = cx.tcx.bound_impl_trait_ref(item.owner_id.to_def_id()).map(|t| t.subst_identity())
                     && let Some(trait_item_id) = cx.tcx.associated_item(owner_id).trait_item_def_id
                 {
                     (

src/tools/clippy/clippy_lints/src/use_self.rs

@@ -133,11 +133,11 @@ impl<'tcx> LateLintPass<'tcx> for UseSelf {
                 ref mut types_to_skip,
                 ..
             }) = self.stack.last_mut();
-            if let Some(impl_trait_ref) = cx.tcx.impl_trait_ref(impl_id);
+            if let Some(impl_trait_ref) = cx.tcx.bound_impl_trait_ref(impl_id.to_def_id());
             then {
                 // `self_ty` is the semantic self type of `impl <trait> for <type>`. This cannot be
                 // `Self`.
-                let self_ty = impl_trait_ref.self_ty();
+                let self_ty = impl_trait_ref.subst_identity().self_ty();
 
                 // `trait_method_sig` is the signature of the function, how it is declared in the
                 // trait, not in the impl of the trait.