Remove bound_{explicit,}_item_bounds

compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs

@@ -673,40 +673,34 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
         let tcx = self.infcx.tcx;
 
         // Find out if the predicates show that the type is a Fn or FnMut
-        let find_fn_kind_from_did = |predicates: ty::EarlyBinder<
-            &[(ty::Predicate<'tcx>, Span)],
-        >,
-                                     substs| {
-            predicates.0.iter().find_map(|(pred, _)| {
-                    let pred = if let Some(substs) = substs {
-                        predicates.rebind(*pred).subst(tcx, substs).kind().skip_binder()
-                    } else {
-                        pred.kind().skip_binder()
-                    };
-                    if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = pred && pred.self_ty() == ty {
-                    if Some(pred.def_id()) == tcx.lang_items().fn_trait() {
-                        return Some(hir::Mutability::Not);
-                    } else if Some(pred.def_id()) == tcx.lang_items().fn_mut_trait() {
-                        return Some(hir::Mutability::Mut);
-                    }
+        let find_fn_kind_from_did = |(pred, _): (ty::Predicate<'tcx>, _)| {
+            if let ty::PredicateKind::Clause(ty::Clause::Trait(pred)) = pred.kind().skip_binder()
+                && pred.self_ty() == ty
+            {
+                if Some(pred.def_id()) == tcx.lang_items().fn_trait() {
+                    return Some(hir::Mutability::Not);
+                } else if Some(pred.def_id()) == tcx.lang_items().fn_mut_trait() {
+                    return Some(hir::Mutability::Mut);
                 }
-                    None
-                })
+            }
+            None
         };
 
         // If the type is opaque/param/closure, and it is Fn or FnMut, let's suggest (mutably)
         // borrowing the type, since `&mut F: FnMut` iff `F: FnMut` and similarly for `Fn`.
         // These types seem reasonably opaque enough that they could be substituted with their
         // borrowed variants in a function body when we see a move error.
-        let borrow_level = match ty.kind() {
-            ty::Param(_) => find_fn_kind_from_did(
-                tcx.bound_explicit_predicates_of(self.mir_def_id().to_def_id())
-                    .map_bound(|p| p.predicates),
-                None,
-            ),
-            ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => {
-                find_fn_kind_from_did(tcx.bound_explicit_item_bounds(*def_id), Some(*substs))
-            }
+        let borrow_level = match *ty.kind() {
+            ty::Param(_) => tcx
+                .explicit_predicates_of(self.mir_def_id().to_def_id())
+                .predicates
+                .iter()
+                .copied()
+                .find_map(find_fn_kind_from_did),
+            ty::Alias(ty::Opaque, ty::AliasTy { def_id, substs, .. }) => tcx
+                .bound_explicit_item_bounds(def_id)
+                .subst_iter_copied(tcx, substs)
+                .find_map(find_fn_kind_from_did),
             ty::Closure(_, substs) => match substs.as_closure().kind() {
                 ty::ClosureKind::Fn => Some(hir::Mutability::Not),
                 ty::ClosureKind::FnMut => Some(hir::Mutability::Mut),

compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -1309,7 +1309,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
     let infcx = wfcx.infcx;
     let tcx = wfcx.tcx();
 
-    let predicates = tcx.bound_predicates_of(def_id.to_def_id());
+    let predicates = tcx.predicates_of(def_id.to_def_id());
     let generics = tcx.generics_of(def_id);
 
     let is_our_default = |def: &ty::GenericParamDef| match def.kind {
@@ -1410,7 +1410,6 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
 
     // Now we build the substituted predicates.
     let default_obligations = predicates
-        .0
         .predicates
         .iter()
         .flat_map(|&(pred, sp)| {
@@ -1441,13 +1440,13 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             }
             let mut param_count = CountParams::default();
             let has_region = pred.visit_with(&mut param_count).is_break();
-            let substituted_pred = predicates.rebind(pred).subst(tcx, substs);
+            let substituted_pred = ty::EarlyBinder(pred).subst(tcx, substs);
             // Don't check non-defaulted params, dependent defaults (including lifetimes)
             // or preds with multiple params.
             if substituted_pred.has_non_region_param() || param_count.params.len() > 1 || has_region
             {
                 None
-            } else if predicates.0.predicates.iter().any(|&(p, _)| p == substituted_pred) {
+            } else if predicates.predicates.iter().any(|&(p, _)| p == substituted_pred) {
                 // Avoid duplication of predicates that contain no parameters, for example.
                 None
             } else {
@@ -1473,7 +1472,7 @@ fn check_where_clauses<'tcx>(wfcx: &WfCheckingCtxt<'_, 'tcx>, span: Span, def_id
             traits::Obligation::new(tcx, cause, wfcx.param_env, pred)
         });
 
-    let predicates = predicates.0.instantiate_identity(tcx);
+    let predicates = predicates.instantiate_identity(tcx);
 
     let predicates = wfcx.normalize(span, None, predicates);
 

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

@@ -330,9 +330,8 @@ impl<'tcx> TypeErrCtxt<'_, 'tcx> {
 
         let Ok(trait_predicates) = self
             .tcx
-            .bound_explicit_predicates_of(trait_item_def_id)
-            .map_bound(|p| p.predicates)
-            .subst_iter_copied(self.tcx, trait_item_substs)
+            .explicit_predicates_of(trait_item_def_id)
+            .instantiate_own(self.tcx, trait_item_substs)
             .map(|(pred, _)| {
                 if pred.is_suggestable(self.tcx, false) {
                     Ok(pred.to_string())

compiler/rustc_middle/src/ty/util.rs

@@ -666,20 +666,6 @@ impl<'tcx> TyCtxt<'tcx> {
         ty::EarlyBinder(self.item_bounds(def_id))
     }
 
-    pub fn bound_predicates_of(
-        self,
-        def_id: DefId,
-    ) -> ty::EarlyBinder<ty::generics::GenericPredicates<'tcx>> {
-        ty::EarlyBinder(self.predicates_of(def_id))
-    }
-
-    pub fn bound_explicit_predicates_of(
-        self,
-        def_id: DefId,
-    ) -> ty::EarlyBinder<ty::generics::GenericPredicates<'tcx>> {
-        ty::EarlyBinder(self.explicit_predicates_of(def_id))
-    }
-
     pub fn bound_impl_subject(self, def_id: DefId) -> ty::EarlyBinder<ty::ImplSubject<'tcx>> {
         ty::EarlyBinder(self.impl_subject(def_id))
     }

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

@@ -2558,12 +2558,11 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
         // obligation will normalize to `<$0 as Iterator>::Item = $1` and
         // `$1: Copy`, so we must ensure the obligations are emitted in
         // that order.
-        let predicates = tcx.bound_predicates_of(def_id);
-        debug!(?predicates);
-        assert_eq!(predicates.0.parent, None);
-        let mut obligations = Vec::with_capacity(predicates.0.predicates.len());
-        for (predicate, span) in predicates.0.predicates {
-            let span = *span;
+        let predicates = tcx.predicates_of(def_id);
+        assert_eq!(predicates.parent, None);
+        let predicates = predicates.instantiate_own(tcx, substs);
+        let mut obligations = Vec::with_capacity(predicates.len());
+        for (predicate, span) in predicates {
             let cause = cause.clone().derived_cause(parent_trait_pred, |derived| {
                 ImplDerivedObligation(Box::new(ImplDerivedObligationCause {
                     derived,
@@ -2576,7 +2575,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> {
                 param_env,
                 cause.clone(),
                 recursion_depth,
-                predicates.rebind(*predicate).subst(tcx, substs),
+                predicate,
                 &mut obligations,
             );
             obligations.push(Obligation { cause, recursion_depth, param_env, predicate });

compiler/rustc_traits/src/chalk/db.rs

@@ -7,7 +7,7 @@
 //! `crate::chalk::lowering` (to lower rustc types into Chalk types).
 
 use rustc_middle::traits::ChalkRustInterner as RustInterner;
-use rustc_middle::ty::{self, AssocKind, EarlyBinder, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
+use rustc_middle::ty::{self, AssocKind, Ty, TyCtxt, TypeFoldable, TypeSuperFoldable};
 use rustc_middle::ty::{InternalSubsts, SubstsRef};
 use rustc_target::abi::{Integer, IntegerType};
 
@@ -38,13 +38,12 @@ impl<'tcx> RustIrDatabase<'tcx> {
         def_id: DefId,
         bound_vars: SubstsRef<'tcx>,
     ) -> Vec<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>> {
-        let predicates = self.interner.tcx.predicates_defined_on(def_id).predicates;
-        predicates
-            .iter()
-            .map(|(wc, _)| EarlyBinder(*wc).subst(self.interner.tcx, bound_vars))
-            .filter_map(|wc| LowerInto::<
-                    Option<chalk_ir::QuantifiedWhereClause<RustInterner<'tcx>>>
-                    >::lower_into(wc, self.interner)).collect()
+        self.interner
+            .tcx
+            .predicates_defined_on(def_id)
+            .instantiate_own(self.interner.tcx, bound_vars)
+            .filter_map(|(wc, _)| LowerInto::lower_into(wc, self.interner))
+            .collect()
     }
 
     fn bounds_for<T>(&self, def_id: DefId, bound_vars: SubstsRef<'tcx>) -> Vec<T>