diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 7bbce730c1658..a63c54a2618b7 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -1569,10 +1569,8 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
         let tcx = self.infcx.tcx;
         let generics = tcx.generics_of(self.mir_def_id());
 
-        let Some(hir_generics) = tcx
-            .typeck_root_def_id(self.mir_def_id().to_def_id())
-            .as_local()
-            .and_then(|def_id| tcx.hir_get_generics(def_id))
+        let Some(hir_generics) =
+            tcx.hir_get_generics(tcx.typeck_root_def_id_local(self.mir_def_id()))
         else {
             return;
         };
diff --git a/compiler/rustc_borrowck/src/diagnostics/mod.rs b/compiler/rustc_borrowck/src/diagnostics/mod.rs
index 8b4bda8f7fefc..86d7119639a3f 100644
--- a/compiler/rustc_borrowck/src/diagnostics/mod.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/mod.rs
@@ -1274,12 +1274,9 @@ impl<'infcx, 'tcx> MirBorrowckCtxt<'_, 'infcx, 'tcx> {
                     if let ty::Param(param_ty) = *self_ty.kind()
                         && let generics = self.infcx.tcx.generics_of(self.mir_def_id())
                         && let param = generics.type_param(param_ty, self.infcx.tcx)
-                        && let Some(hir_generics) = self
-                            .infcx
-                            .tcx
-                            .typeck_root_def_id(self.mir_def_id().to_def_id())
-                            .as_local()
-                            .and_then(|def_id| self.infcx.tcx.hir_get_generics(def_id))
+                        && let Some(hir_generics) = self.infcx.tcx.hir_get_generics(
+                            self.infcx.tcx.typeck_root_def_id_local(self.mir_def_id()),
+                        )
                         && let spans = hir_generics
                             .predicates
                             .iter()
diff --git a/compiler/rustc_borrowck/src/universal_regions.rs b/compiler/rustc_borrowck/src/universal_regions.rs
index aeba5ee70cf17..e96c6c7c56f9b 100644
--- a/compiler/rustc_borrowck/src/universal_regions.rs
+++ b/compiler/rustc_borrowck/src/universal_regions.rs
@@ -476,12 +476,10 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         let mut indices = self.compute_indices(fr_static, defining_ty);
         debug!("build: indices={:?}", indices);
 
-        let typeck_root_def_id = self.infcx.tcx.typeck_root_def_id(self.mir_def.to_def_id());
-
         // If this is a 'root' body (not a closure/coroutine/inline const), then
         // there are no extern regions, so the local regions start at the same
         // position as the (empty) sub-list of extern regions
-        let first_local_index = if self.mir_def.to_def_id() == typeck_root_def_id {
+        let first_local_index = if !self.infcx.tcx.is_typeck_child(self.mir_def.to_def_id()) {
             first_extern_index
         } else {
             // If this is a closure, coroutine, or inline-const, then the late-bound regions from the enclosing
@@ -583,7 +581,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
     /// see `DefiningTy` for details.
     fn defining_ty(&self) -> DefiningTy<'tcx> {
         let tcx = self.infcx.tcx;
-        let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.to_def_id());
+        let typeck_root_def_id = tcx.typeck_root_def_id_local(self.mir_def);
 
         match tcx.hir_body_owner_kind(self.mir_def) {
             BodyOwnerKind::Closure | BodyOwnerKind::Fn => {
@@ -614,7 +612,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
 
             BodyOwnerKind::Const { .. } | BodyOwnerKind::Static(..) => {
                 let identity_args = GenericArgs::identity_for_item(tcx, typeck_root_def_id);
-                if self.mir_def.to_def_id() == typeck_root_def_id {
+                if self.mir_def == typeck_root_def_id {
                     let args = self.infcx.replace_free_regions_with_nll_infer_vars(
                         NllRegionVariableOrigin::FreeRegion,
                         identity_args,
@@ -660,7 +658,7 @@ impl<'cx, 'tcx> UniversalRegionsBuilder<'cx, 'tcx> {
         defining_ty: DefiningTy<'tcx>,
     ) -> UniversalRegionIndices<'tcx> {
         let tcx = self.infcx.tcx;
-        let typeck_root_def_id = tcx.typeck_root_def_id(self.mir_def.to_def_id());
+        let typeck_root_def_id = tcx.typeck_root_def_id_local(self.mir_def);
         let identity_args = GenericArgs::identity_for_item(tcx, typeck_root_def_id);
         let renumbered_args = defining_ty.args();
 
@@ -948,16 +946,14 @@ fn for_each_late_bound_region_in_recursive_scope<'tcx>(
     mut mir_def_id: LocalDefId,
     mut f: impl FnMut(ty::Region<'tcx>),
 ) {
-    let typeck_root_def_id = tcx.typeck_root_def_id(mir_def_id.to_def_id());
-
     // Walk up the tree, collecting late-bound regions until we hit the typeck root
     loop {
         for_each_late_bound_region_in_item(tcx, mir_def_id, &mut f);
 
-        if mir_def_id.to_def_id() == typeck_root_def_id {
-            break;
-        } else {
+        if tcx.is_typeck_child(mir_def_id.to_def_id()) {
             mir_def_id = tcx.local_parent(mir_def_id);
+        } else {
+            break;
         }
     }
 }
diff --git a/compiler/rustc_hir_analysis/src/check/region.rs b/compiler/rustc_hir_analysis/src/check/region.rs
index 8865638e3af2f..e31beca390837 100644
--- a/compiler/rustc_hir_analysis/src/check/region.rs
+++ b/compiler/rustc_hir_analysis/src/check/region.rs
@@ -11,7 +11,7 @@ use std::mem;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_hir as hir;
 use rustc_hir::def::{CtorKind, DefKind, Res};
-use rustc_hir::def_id::DefId;
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::{self, Visitor};
 use rustc_hir::{Arm, Block, Expr, LetStmt, Pat, PatKind, Stmt};
 use rustc_index::Idx;
@@ -849,13 +849,13 @@ impl<'tcx> Visitor<'tcx> for ScopeResolutionVisitor<'tcx> {
 /// re-use in incremental scenarios. We may sometimes need to rerun the
 /// type checker even when the HIR hasn't changed, and in those cases
 /// we can avoid reconstructing the region scope tree.
-pub(crate) fn region_scope_tree(tcx: TyCtxt<'_>, def_id: DefId) -> &ScopeTree {
-    let typeck_root_def_id = tcx.typeck_root_def_id(def_id);
+pub(crate) fn region_scope_tree(tcx: TyCtxt<'_>, def_id: LocalDefId) -> &ScopeTree {
+    let typeck_root_def_id = tcx.typeck_root_def_id_local(def_id);
     if typeck_root_def_id != def_id {
         return tcx.region_scope_tree(typeck_root_def_id);
     }
 
-    let scope_tree = if let Some(body) = tcx.hir_maybe_body_owned_by(def_id.expect_local()) {
+    let scope_tree = if let Some(body) = tcx.hir_maybe_body_owned_by(def_id) {
         let mut visitor = ScopeResolutionVisitor {
             tcx,
             scope_tree: ScopeTree::default(),
diff --git a/compiler/rustc_hir_analysis/src/collect/generics_of.rs b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
index 866787a457180..ea98beb955805 100644
--- a/compiler/rustc_hir_analysis/src/collect/generics_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/generics_of.rs
@@ -76,12 +76,12 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         | Node::Ctor(..)
         | Node::Field(_) => {
             let parent_id = tcx.hir_get_parent_item(hir_id);
-            Some(parent_id.to_def_id())
+            Some(parent_id.def_id)
         }
         // FIXME(#43408) always enable this once `lazy_normalization` is
         // stable enough and does not need a feature gate anymore.
         Node::AnonConst(_) => {
-            let parent_did = tcx.parent(def_id.to_def_id());
+            let parent_did = tcx.local_parent(def_id);
             debug!(?parent_did);
 
             let mut in_param_ty = false;
@@ -175,7 +175,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         }
         Node::ConstBlock(_)
         | Node::Expr(&hir::Expr { kind: hir::ExprKind::Closure { .. }, .. }) => {
-            Some(tcx.typeck_root_def_id(def_id.to_def_id()))
+            Some(tcx.typeck_root_def_id_local(def_id))
         }
         Node::OpaqueTy(&hir::OpaqueTy {
             origin:
@@ -188,7 +188,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
             } else {
                 assert_matches!(tcx.def_kind(fn_def_id), DefKind::AssocFn | DefKind::Fn);
             }
-            Some(fn_def_id.to_def_id())
+            Some(fn_def_id)
         }
         Node::OpaqueTy(&hir::OpaqueTy {
             origin: hir::OpaqueTyOrigin::TyAlias { parent, in_assoc_ty },
@@ -202,7 +202,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
             debug!("generics_of: parent of opaque ty {:?} is {:?}", def_id, parent);
             // Opaque types are always nested within another item, and
             // inherit the generics of the item.
-            Some(parent.to_def_id())
+            Some(parent)
         }
 
         // All of these nodes have no parent from which to inherit generics.
@@ -380,7 +380,7 @@ pub(super) fn generics_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Generics {
         own_params.iter().map(|param| (param.def_id, param.index)).collect();
 
     ty::Generics {
-        parent: parent_def_id,
+        parent: parent_def_id.map(LocalDefId::to_def_id),
         parent_count,
         own_params,
         param_def_id_to_index,
diff --git a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
index 98999232a7435..8fd3d631962c8 100644
--- a/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
+++ b/compiler/rustc_hir_analysis/src/collect/predicates_of.rs
@@ -107,7 +107,7 @@ fn gather_explicit_predicates_of(tcx: TyCtxt<'_>, def_id: LocalDefId) -> ty::Gen
             );
 
             return ty::GenericPredicates {
-                parent: Some(tcx.parent(def_id.to_def_id())),
+                parent: Some(tcx.local_parent(def_id).to_def_id()),
                 predicates: tcx.arena.alloc_from_iter(predicates),
             };
         }
diff --git a/compiler/rustc_hir_typeck/src/closure.rs b/compiler/rustc_hir_typeck/src/closure.rs
index 82b7c578a1f25..1a9c2a21c7ef3 100644
--- a/compiler/rustc_hir_typeck/src/closure.rs
+++ b/compiler/rustc_hir_typeck/src/closure.rs
@@ -72,7 +72,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         debug!(?bound_sig, ?liberated_sig);
 
         let parent_args =
-            GenericArgs::identity_for_item(tcx, tcx.typeck_root_def_id(expr_def_id.to_def_id()));
+            GenericArgs::identity_for_item(tcx, tcx.typeck_root_def_id_local(expr_def_id));
 
         let tupled_upvars_ty = self.next_ty_var(expr_span);
 
diff --git a/compiler/rustc_hir_typeck/src/lib.rs b/compiler/rustc_hir_typeck/src/lib.rs
index 734e5136f8806..6cfcdfe87480e 100644
--- a/compiler/rustc_hir_typeck/src/lib.rs
+++ b/compiler/rustc_hir_typeck/src/lib.rs
@@ -106,7 +106,7 @@ fn typeck_with_inspect<'tcx>(
 ) -> &'tcx ty::TypeckResults<'tcx> {
     // Closures' typeck results come from their outermost function,
     // as they are part of the same "inference environment".
-    let typeck_root_def_id = tcx.typeck_root_def_id(def_id.to_def_id()).expect_local();
+    let typeck_root_def_id = tcx.typeck_root_def_id_local(def_id);
     if typeck_root_def_id != def_id {
         return tcx.typeck(typeck_root_def_id);
     }
diff --git a/compiler/rustc_metadata/src/rmeta/encoder.rs b/compiler/rustc_metadata/src/rmeta/encoder.rs
index e554da362f83e..8bf919dab8e79 100644
--- a/compiler/rustc_metadata/src/rmeta/encoder.rs
+++ b/compiler/rustc_metadata/src/rmeta/encoder.rs
@@ -727,7 +727,7 @@ impl<'a, 'tcx> EncodeContext<'a, 'tcx> {
                     is_stub: false,
                 },
                 extra_filename: tcx.sess.opts.cg.extra_filename.clone(),
-                stable_crate_id: tcx.def_path_hash(LOCAL_CRATE.as_def_id()).stable_crate_id(),
+                stable_crate_id: tcx.stable_crate_id(LOCAL_CRATE),
                 required_panic_strategy: tcx.required_panic_strategy(LOCAL_CRATE),
                 panic_in_drop_strategy: tcx.sess.opts.unstable_opts.panic_in_drop,
                 edition: tcx.sess.edition(),
diff --git a/compiler/rustc_middle/src/queries.rs b/compiler/rustc_middle/src/queries.rs
index ff96f5044dc14..3572e3ff35cbe 100644
--- a/compiler/rustc_middle/src/queries.rs
+++ b/compiler/rustc_middle/src/queries.rs
@@ -1413,7 +1413,7 @@ rustc_queries! {
 
     /// Per-body `region::ScopeTree`. The `DefId` should be the owner `DefId` for the body;
     /// in the case of closures, this will be redirected to the enclosing function.
-    query region_scope_tree(def_id: DefId) -> &'tcx crate::middle::region::ScopeTree {
+    query region_scope_tree(def_id: LocalDefId) -> &'tcx crate::middle::region::ScopeTree {
         desc { "computing drop scopes for `{}`", tcx.def_path_str(def_id) }
     }
 
diff --git a/compiler/rustc_middle/src/ty/context.rs b/compiler/rustc_middle/src/ty/context.rs
index 58a2edca8ecef..28688bcbfafc4 100644
--- a/compiler/rustc_middle/src/ty/context.rs
+++ b/compiler/rustc_middle/src/ty/context.rs
@@ -899,12 +899,8 @@ impl<'tcx> TyCtxt<'tcx> {
     pub fn has_typeck_results(self, def_id: LocalDefId) -> bool {
         // Closures' typeck results come from their outermost function,
         // as they are part of the same "inference environment".
-        let typeck_root_def_id = self.typeck_root_def_id(def_id.to_def_id());
-        if typeck_root_def_id != def_id.to_def_id() {
-            return self.has_typeck_results(typeck_root_def_id.expect_local());
-        }
-
-        self.hir_node_by_def_id(def_id).body_id().is_some()
+        let root = self.typeck_root_def_id_local(def_id);
+        self.hir_node_by_def_id(root).body_id().is_some()
     }
 
     /// Expects a body and returns its codegen attributes.
diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs
index e7c7d59248700..d0cbdff366dfa 100644
--- a/compiler/rustc_middle/src/ty/util.rs
+++ b/compiler/rustc_middle/src/ty/util.rs
@@ -650,6 +650,20 @@ impl<'tcx> TyCtxt<'tcx> {
         def_id
     }
 
+    /// Given the `LocalDefId`, returns the `LocalDefId` of the innermost item that
+    /// has its own type-checking context or "inference environment".
+    ///
+    /// For example, a closure has its own `LocalDefId`, but it is type-checked
+    /// with the containing item. Therefore, when we fetch the `typeck` of the closure,
+    /// for example, we really wind up fetching the `typeck` of the enclosing fn item.
+    pub fn typeck_root_def_id_local(self, def_id: LocalDefId) -> LocalDefId {
+        let mut def_id = def_id;
+        while self.is_typeck_child(def_id.to_def_id()) {
+            def_id = self.local_parent(def_id);
+        }
+        def_id
+    }
+
     /// Given the `DefId` and args a closure, creates the type of
     /// `self` argument that the closure expects. For example, for a
     /// `Fn` closure, this would return a reference type `&T` where
diff --git a/compiler/rustc_mir_build/src/thir/cx/expr.rs b/compiler/rustc_mir_build/src/thir/cx/expr.rs
index 4256ee45f8501..7e6f30378a490 100644
--- a/compiler/rustc_mir_build/src/thir/cx/expr.rs
+++ b/compiler/rustc_mir_build/src/thir/cx/expr.rs
@@ -816,8 +816,8 @@ impl<'tcx> ThirBuildCx<'tcx> {
                         }
                         hir::InlineAsmOperand::Const { ref anon_const } => {
                             let ty = self.typeck_results.node_type(anon_const.hir_id);
-                            let did = anon_const.def_id.to_def_id();
-                            let typeck_root_def_id = tcx.typeck_root_def_id(did);
+                            let did = anon_const.def_id;
+                            let typeck_root_def_id = tcx.typeck_root_def_id_local(did);
                             let parent_args = tcx.erase_and_anonymize_regions(
                                 GenericArgs::identity_for_item(tcx, typeck_root_def_id),
                             );
@@ -825,7 +825,7 @@ impl<'tcx> ThirBuildCx<'tcx> {
                                 InlineConstArgs::new(tcx, InlineConstArgsParts { parent_args, ty })
                                     .args;
 
-                            let uneval = mir::UnevaluatedConst::new(did, args);
+                            let uneval = mir::UnevaluatedConst::new(did.to_def_id(), args);
                             let value = mir::Const::Unevaluated(uneval, ty);
                             InlineAsmOperand::Const { value, span: tcx.def_span(did) }
                         }
@@ -895,15 +895,15 @@ impl<'tcx> ThirBuildCx<'tcx> {
 
             hir::ExprKind::ConstBlock(ref anon_const) => {
                 let ty = self.typeck_results.node_type(anon_const.hir_id);
-                let did = anon_const.def_id.to_def_id();
-                let typeck_root_def_id = tcx.typeck_root_def_id(did);
+                let did = anon_const.def_id;
+                let typeck_root_def_id = tcx.typeck_root_def_id_local(did);
                 let parent_args = tcx.erase_and_anonymize_regions(GenericArgs::identity_for_item(
                     tcx,
                     typeck_root_def_id,
                 ));
                 let args = InlineConstArgs::new(tcx, InlineConstArgsParts { parent_args, ty }).args;
 
-                ExprKind::ConstBlock { did, args }
+                ExprKind::ConstBlock { did: did.to_def_id(), args }
             }
             // Now comes the rote stuff:
             hir::ExprKind::Repeat(v, _) => {
diff --git a/compiler/rustc_mir_transform/src/lib.rs b/compiler/rustc_mir_transform/src/lib.rs
index 094aae499c4b4..9273c2103d442 100644
--- a/compiler/rustc_mir_transform/src/lib.rs
+++ b/compiler/rustc_mir_transform/src/lib.rs
@@ -526,7 +526,7 @@ fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &
 
     // We only need to borrowck non-synthetic MIR.
     let tainted_by_errors = if !tcx.is_synthetic_mir(def) {
-        tcx.mir_borrowck(tcx.typeck_root_def_id(def.to_def_id()).expect_local()).err()
+        tcx.mir_borrowck(tcx.typeck_root_def_id_local(def)).err()
     } else {
         None
     };
@@ -554,14 +554,14 @@ fn mir_drops_elaborated_and_const_checked(tcx: TyCtxt<'_>, def: LocalDefId) -> &
     //
     // We do this check here and not during `mir_promoted` because that may result
     // in borrowck cycles if WF requires looking into an opaque hidden type.
-    let root = tcx.typeck_root_def_id(def.to_def_id());
+    let root = tcx.typeck_root_def_id_local(def);
     match tcx.def_kind(root) {
         DefKind::Fn
         | DefKind::AssocFn
         | DefKind::Static { .. }
         | DefKind::Const { .. }
         | DefKind::AssocConst { .. } => {
-            if let Err(guar) = tcx.ensure_result().check_well_formed(root.expect_local()) {
+            if let Err(guar) = tcx.ensure_result().check_well_formed(root) {
                 body.tainted_by_errors = Some(guar);
             }
         }
@@ -840,7 +840,7 @@ fn promoted_mir(tcx: TyCtxt<'_>, def: LocalDefId) -> &IndexVec<Promoted, Body<'_
     }
 
     if !tcx.is_synthetic_mir(def) {
-        tcx.ensure_done().mir_borrowck(tcx.typeck_root_def_id(def.to_def_id()).expect_local());
+        tcx.ensure_done().mir_borrowck(tcx.typeck_root_def_id_local(def));
     }
     let mut promoted = tcx.mir_promoted(def).1.steal();
 
diff --git a/compiler/rustc_mir_transform/src/liveness.rs b/compiler/rustc_mir_transform/src/liveness.rs
index af246735b95a7..90b6f07df8367 100644
--- a/compiler/rustc_mir_transform/src/liveness.rs
+++ b/compiler/rustc_mir_transform/src/liveness.rs
@@ -67,7 +67,7 @@ pub(crate) fn check_liveness<'tcx>(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> Den
     }
 
     // Don't run unused pass for #[derive]
-    let parent = tcx.parent(tcx.typeck_root_def_id(def_id.to_def_id()));
+    let parent = tcx.local_parent(tcx.typeck_root_def_id_local(def_id));
     if let DefKind::Impl { of_trait: true } = tcx.def_kind(parent)
         && find_attr!(tcx, parent, AutomaticallyDerived(..))
     {
diff --git a/compiler/rustc_monomorphize/src/collector.rs b/compiler/rustc_monomorphize/src/collector.rs
index 8bd6730ab0eba..4698e054daf6e 100644
--- a/compiler/rustc_monomorphize/src/collector.rs
+++ b/compiler/rustc_monomorphize/src/collector.rs
@@ -1615,7 +1615,7 @@ impl<'v> RootCollector<'_, 'v> {
                 if (self.strategy == MonoItemCollectionStrategy::Eager || is_pub_fn_coroutine)
                     && !self
                         .tcx
-                        .generics_of(self.tcx.typeck_root_def_id(def_id.to_def_id()))
+                        .generics_of(self.tcx.typeck_root_def_id_local(def_id))
                         .requires_monomorphization(self.tcx)
                 {
                     let instance = match *self.tcx.type_of(def_id).instantiate_identity().kind() {
diff --git a/compiler/rustc_passes/src/dead.rs b/compiler/rustc_passes/src/dead.rs
index 30634c800e819..d5ef9ee9335c5 100644
--- a/compiler/rustc_passes/src/dead.rs
+++ b/compiler/rustc_passes/src/dead.rs
@@ -380,8 +380,8 @@ impl<'tcx> MarkSymbolVisitor<'tcx> {
     /// for discussion).
     fn should_ignore_impl_item(&mut self, impl_item: &hir::ImplItem<'_>) -> bool {
         if let hir::ImplItemImplKind::Trait { .. } = impl_item.impl_kind
-            && let impl_of = self.tcx.parent(impl_item.owner_id.to_def_id())
-            && self.tcx.is_automatically_derived(impl_of)
+            && let impl_of = self.tcx.local_parent(impl_item.owner_id.def_id)
+            && self.tcx.is_automatically_derived(impl_of.to_def_id())
             && let trait_ref = self.tcx.impl_trait_ref(impl_of).instantiate_identity()
             && find_attr!(self.tcx, trait_ref.def_id, RustcTrivialFieldReads)
         {
diff --git a/compiler/rustc_symbol_mangling/src/legacy.rs b/compiler/rustc_symbol_mangling/src/legacy.rs
index ea16231880e2c..54ecf277cd3df 100644
--- a/compiler/rustc_symbol_mangling/src/legacy.rs
+++ b/compiler/rustc_symbol_mangling/src/legacy.rs
@@ -155,9 +155,7 @@ fn get_symbol_hash<'tcx>(
             args.hash_stable(hcx, &mut hasher);
 
             if let Some(instantiating_crate) = instantiating_crate {
-                tcx.def_path_hash(instantiating_crate.as_def_id())
-                    .stable_crate_id()
-                    .hash_stable(hcx, &mut hasher);
+                tcx.stable_crate_id(instantiating_crate).hash_stable(hcx, &mut hasher);
             }
 
             // We want to avoid accidental collision between different types of instances.
diff --git a/compiler/rustc_symbol_mangling/src/v0.rs b/compiler/rustc_symbol_mangling/src/v0.rs
index 95cbb9e07ebb7..eff8cbef99541 100644
--- a/compiler/rustc_symbol_mangling/src/v0.rs
+++ b/compiler/rustc_symbol_mangling/src/v0.rs
@@ -841,7 +841,7 @@ impl<'tcx> Printer<'tcx> for V0SymbolMangler<'tcx> {
     fn print_crate_name(&mut self, cnum: CrateNum) -> Result<(), PrintError> {
         self.push("C");
         if !self.is_exportable {
-            let stable_crate_id = self.tcx.def_path_hash(cnum.as_def_id()).stable_crate_id();
+            let stable_crate_id = self.tcx.stable_crate_id(cnum);
             self.push_disambiguator(stable_crate_id.as_u64());
         }
         let name = self.tcx.crate_name(cnum);
diff --git a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
index 7fcaea3a629f1..46bc9bdee04b8 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/infer/need_type_info.rs
@@ -507,18 +507,17 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         };
 
         let mut local_visitor = FindInferSourceVisitor::new(self, typeck_results, term, ty);
-        if let Some(body) = self.tcx.hir_maybe_body_owned_by(
-            self.tcx.typeck_root_def_id(body_def_id.to_def_id()).expect_local(),
-        ) {
+        if let Some(body) =
+            self.tcx.hir_maybe_body_owned_by(self.tcx.typeck_root_def_id_local(body_def_id))
+        {
             let expr = body.value;
             local_visitor.visit_expr(expr);
         }
 
         let Some(InferSource { span, kind }) = local_visitor.infer_source else {
             let silence = if let DefKind::AssocFn = self.tcx.def_kind(body_def_id)
-                && let parent = self.tcx.parent(body_def_id.into())
-                && self.tcx.is_automatically_derived(parent)
-                && let Some(parent) = parent.as_local()
+                && let parent = self.tcx.local_parent(body_def_id)
+                && self.tcx.is_automatically_derived(parent.to_def_id())
                 && let hir::Node::Item(item) = self.tcx.hir_node_by_def_id(parent)
                 && let hir::ItemKind::Impl(imp) = item.kind
                 && let hir::TyKind::Path(hir::QPath::Resolved(_, path)) = imp.self_ty.kind
diff --git a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
index 4a6d5eb48f8f1..a16bbf20238c0 100644
--- a/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
+++ b/compiler/rustc_trait_selection/src/error_reporting/traits/suggestions.rs
@@ -1966,10 +1966,9 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
 
         let mut span = obligation.cause.span;
         if let DefKind::Closure = self.tcx.def_kind(obligation.cause.body_id)
-            && let parent = self.tcx.parent(obligation.cause.body_id.into())
+            && let parent = self.tcx.local_parent(obligation.cause.body_id)
             && let DefKind::Fn | DefKind::AssocFn = self.tcx.def_kind(parent)
             && self.tcx.asyncness(parent).is_async()
-            && let Some(parent) = parent.as_local()
             && let Node::Item(hir::Item { kind: hir::ItemKind::Fn { sig: fn_sig, .. }, .. })
             | Node::ImplItem(hir::ImplItem { kind: hir::ImplItemKind::Fn(fn_sig, _), .. })
             | Node::TraitItem(hir::TraitItem {
diff --git a/compiler/rustc_ty_utils/src/nested_bodies.rs b/compiler/rustc_ty_utils/src/nested_bodies.rs
index 11dfbad7dbb7a..874c8161453b3 100644
--- a/compiler/rustc_ty_utils/src/nested_bodies.rs
+++ b/compiler/rustc_ty_utils/src/nested_bodies.rs
@@ -1,27 +1,26 @@
 use rustc_hir as hir;
-use rustc_hir::def_id::{DefId, LocalDefId};
+use rustc_hir::def_id::LocalDefId;
 use rustc_hir::intravisit::Visitor;
 use rustc_middle::query::Providers;
 use rustc_middle::ty::{self, TyCtxt};
 
 fn nested_bodies_within<'tcx>(tcx: TyCtxt<'tcx>, item: LocalDefId) -> &'tcx ty::List<LocalDefId> {
     let body = tcx.hir_body_owned_by(item);
-    let mut collector =
-        NestedBodiesVisitor { tcx, root_def_id: item.to_def_id(), nested_bodies: vec![] };
+    let mut collector = NestedBodiesVisitor { tcx, root_def_id: item, nested_bodies: vec![] };
     collector.visit_body(body);
     tcx.mk_local_def_ids(&collector.nested_bodies)
 }
 
 struct NestedBodiesVisitor<'tcx> {
     tcx: TyCtxt<'tcx>,
-    root_def_id: DefId,
+    root_def_id: LocalDefId,
     nested_bodies: Vec<LocalDefId>,
 }
 
 impl<'tcx> Visitor<'tcx> for NestedBodiesVisitor<'tcx> {
     fn visit_nested_body(&mut self, id: hir::BodyId) {
         let body_def_id = self.tcx.hir_body_owner_def_id(id);
-        if self.tcx.typeck_root_def_id(body_def_id.to_def_id()) == self.root_def_id {
+        if self.tcx.typeck_root_def_id_local(body_def_id) == self.root_def_id {
             // We visit nested bodies before adding the current body. This
             // means that nested bodies are always stored before their parent.
             let body = self.tcx.hir_body(id);
diff --git a/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs b/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
index 8b0743c8d9d59..6c45964da0dab 100644
--- a/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
+++ b/src/tools/clippy/clippy_lints/src/only_used_in_recursion.rs
@@ -332,7 +332,7 @@ impl<'tcx> LateLintPass<'tcx> for OnlyUsedInRecursion {
                 if let ImplItemImplKind::Trait { trait_item_def_id, .. } = impl_kind
                     && let Ok(trait_item_id) = trait_item_def_id
                 {
-                    let impl_id = cx.tcx.parent(owner_id.into());
+                    let impl_id = cx.tcx.local_parent(owner_id.def_id);
                     let trait_ref = cx.tcx.impl_trait_ref(impl_id).instantiate_identity();
                     (
                         trait_item_id,
diff --git a/src/tools/clippy/clippy_lints/src/shadow.rs b/src/tools/clippy/clippy_lints/src/shadow.rs
index 4fa22ff0cdb5a..4ddf82773d872 100644
--- a/src/tools/clippy/clippy_lints/src/shadow.rs
+++ b/src/tools/clippy/clippy_lints/src/shadow.rs
@@ -179,7 +179,7 @@ impl<'tcx> LateLintPass<'tcx> for Shadow {
 }
 
 fn is_shadow(cx: &LateContext<'_>, owner: LocalDefId, first: ItemLocalId, second: ItemLocalId) -> bool {
-    let scope_tree = cx.tcx.region_scope_tree(owner.to_def_id());
+    let scope_tree = cx.tcx.region_scope_tree(owner);
     if let Some(first_scope) = scope_tree.var_scope(first)
         && let Some(second_scope) = scope_tree.var_scope(second)
     {