4 files changed, 3 insertions, 198 deletions
diff --git a/compiler/rustc_hir/Cargo.toml b/compiler/rustc_hir/Cargo.toml
index 592a9996c8f..1008a3e787d 100644
--- a/compiler/rustc_hir/Cargo.toml
+++ b/compiler/rustc_hir/Cargo.toml
@@ -14,6 +14,7 @@ rustc_ast_pretty = { path = "../rustc_ast_pretty" }
 rustc_data_structures = { path = "../rustc_data_structures" }
 rustc_error_messages = { path = "../rustc_error_messages" }
 rustc_hashes = { path = "../rustc_hashes" }
+rustc_hir_id = { path = "../rustc_hir_id" }
 rustc_index = { path = "../rustc_index" }
 rustc_macros = { path = "../rustc_macros" }
 rustc_serialize = { path = "../rustc_serialize" }
diff --git a/compiler/rustc_hir/src/hir_id.rs b/compiler/rustc_hir/src/hir_id.rs
deleted file mode 100644
index b48a081d371..00000000000
--- a/compiler/rustc_hir/src/hir_id.rs
+++ /dev/null
@@ -1,173 +0,0 @@
-use std::fmt::{self, Debug};
-
-use rustc_data_structures::stable_hasher::{HashStable, StableHasher, StableOrd, ToStableHashKey};
-use rustc_macros::{Decodable, Encodable, HashStable_Generic};
-use rustc_span::HashStableContext;
-use rustc_span::def_id::DefPathHash;
-
-use crate::def_id::{CRATE_DEF_ID, DefId, DefIndex, LocalDefId};
-
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable)]
-pub struct OwnerId {
-    pub def_id: LocalDefId,
-}
-
-impl Debug for OwnerId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        // Example: DefId(0:1 ~ aa[7697]::{use#0})
-        Debug::fmt(&self.def_id, f)
-    }
-}
-
-impl From<OwnerId> for HirId {
-    fn from(owner: OwnerId) -> HirId {
-        HirId { owner, local_id: ItemLocalId::ZERO }
-    }
-}
-
-impl From<OwnerId> for DefId {
-    fn from(value: OwnerId) -> Self {
-        value.to_def_id()
-    }
-}
-
-impl OwnerId {
-    #[inline]
-    pub fn to_def_id(self) -> DefId {
-        self.def_id.to_def_id()
-    }
-}
-
-impl rustc_index::Idx for OwnerId {
-    #[inline]
-    fn new(idx: usize) -> Self {
-        OwnerId { def_id: LocalDefId { local_def_index: DefIndex::from_usize(idx) } }
-    }
-
-    #[inline]
-    fn index(self) -> usize {
-        self.def_id.local_def_index.as_usize()
-    }
-}
-
-impl<CTX: HashStableContext> HashStable<CTX> for OwnerId {
-    #[inline]
-    fn hash_stable(&self, hcx: &mut CTX, hasher: &mut StableHasher) {
-        self.to_stable_hash_key(hcx).hash_stable(hcx, hasher);
-    }
-}
-
-impl<CTX: HashStableContext> ToStableHashKey<CTX> for OwnerId {
-    type KeyType = DefPathHash;
-
-    #[inline]
-    fn to_stable_hash_key(&self, hcx: &CTX) -> DefPathHash {
-        hcx.def_path_hash(self.to_def_id())
-    }
-}
-
-/// Uniquely identifies a node in the HIR of the current crate. It is
-/// composed of the `owner`, which is the `LocalDefId` of the directly enclosing
-/// `hir::Item`, `hir::TraitItem`, or `hir::ImplItem` (i.e., the closest "item-like"),
-/// and the `local_id` which is unique within the given owner.
-///
-/// This two-level structure makes for more stable values: One can move an item
-/// around within the source code, or add or remove stuff before it, without
-/// the `local_id` part of the `HirId` changing, which is a very useful property in
-/// incremental compilation where we have to persist things through changes to
-/// the code base.
-#[derive(Copy, Clone, PartialEq, Eq, Hash, Encodable, Decodable, HashStable_Generic)]
-#[rustc_pass_by_value]
-pub struct HirId {
-    pub owner: OwnerId,
-    pub local_id: ItemLocalId,
-}
-
-// To ensure correctness of incremental compilation,
-// `HirId` must not implement `Ord` or `PartialOrd`.
-// See https://github.com/rust-lang/rust/issues/90317.
-impl !Ord for HirId {}
-impl !PartialOrd for HirId {}
-
-impl Debug for HirId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        // Example: HirId(DefId(0:1 ~ aa[7697]::{use#0}).10)
-        // Don't use debug_tuple to always keep this on one line.
-        write!(f, "HirId({:?}.{:?})", self.owner, self.local_id)
-    }
-}
-
-impl HirId {
-    /// Signal local id which should never be used.
-    pub const INVALID: HirId =
-        HirId { owner: OwnerId { def_id: CRATE_DEF_ID }, local_id: ItemLocalId::INVALID };
-
-    #[inline]
-    pub fn expect_owner(self) -> OwnerId {
-        assert_eq!(self.local_id.index(), 0);
-        self.owner
-    }
-
-    #[inline]
-    pub fn as_owner(self) -> Option<OwnerId> {
-        if self.local_id.index() == 0 { Some(self.owner) } else { None }
-    }
-
-    #[inline]
-    pub fn is_owner(self) -> bool {
-        self.local_id.index() == 0
-    }
-
-    #[inline]
-    pub fn make_owner(owner: LocalDefId) -> Self {
-        Self { owner: OwnerId { def_id: owner }, local_id: ItemLocalId::ZERO }
-    }
-}
-
-impl fmt::Display for HirId {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{self:?}")
-    }
-}
-
-rustc_data_structures::define_stable_id_collections!(HirIdMap, HirIdSet, HirIdMapEntry, HirId);
-rustc_data_structures::define_id_collections!(
-    ItemLocalMap,
-    ItemLocalSet,
-    ItemLocalMapEntry,
-    ItemLocalId
-);
-
-rustc_index::newtype_index! {
-    /// An `ItemLocalId` uniquely identifies something within a given "item-like";
-    /// that is, within a `hir::Item`, `hir::TraitItem`, or `hir::ImplItem`. There is no
-    /// guarantee that the numerical value of a given `ItemLocalId` corresponds to
-    /// the node's position within the owning item in any way, but there is a
-    /// guarantee that the `ItemLocalId`s within an owner occupy a dense range of
-    /// integers starting at zero, so a mapping that maps all or most nodes within
-    /// an "item-like" to something else can be implemented by a `Vec` instead of a
-    /// tree or hash map.
-    #[derive(HashStable_Generic)]
-    #[encodable]
-    #[orderable]
-    pub struct ItemLocalId {}
-}
-
-impl ItemLocalId {
-    /// Signal local id which should never be used.
-    pub const INVALID: ItemLocalId = ItemLocalId::MAX;
-}
-
-impl StableOrd for ItemLocalId {
-    const CAN_USE_UNSTABLE_SORT: bool = true;
-
-    // `Ord` is implemented as just comparing the ItemLocalId's numerical
-    // values and these are not changed by (de-)serialization.
-    const THIS_IMPLEMENTATION_HAS_BEEN_TRIPLE_CHECKED: () = ();
-}
-
-/// The `HirId` corresponding to `CRATE_NODE_ID` and `CRATE_DEF_ID`.
-pub const CRATE_HIR_ID: HirId =
-    HirId { owner: OwnerId { def_id: CRATE_DEF_ID }, local_id: ItemLocalId::ZERO };
-
-pub const CRATE_OWNER_ID: OwnerId = OwnerId { def_id: CRATE_DEF_ID };
diff --git a/compiler/rustc_hir/src/lib.rs b/compiler/rustc_hir/src/lib.rs
index f1212d07ff6..78fc63753a2 100644
--- a/compiler/rustc_hir/src/lib.rs
+++ b/compiler/rustc_hir/src/lib.rs
@@ -3,14 +3,11 @@
 //! [rustc dev guide]: https://rustc-dev-guide.rust-lang.org/hir.html
 
 // tidy-alphabetical-start
-#![allow(internal_features)]
 #![feature(associated_type_defaults)]
 #![feature(closure_track_caller)]
 #![feature(debug_closure_helpers)]
 #![feature(exhaustive_patterns)]
-#![feature(negative_impls)]
 #![feature(never_type)]
-#![feature(rustc_attrs)]
 #![feature(variant_count)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
@@ -25,7 +22,7 @@ pub mod definitions;
 pub mod diagnostic_items;
 pub use rustc_span::def_id;
 mod hir;
-pub mod hir_id;
+pub use rustc_hir_id::{self as hir_id, *};
 pub mod intravisit;
 pub mod lang_items;
 pub mod lints;
@@ -41,7 +38,6 @@ mod tests;
 
 #[doc(no_inline)]
 pub use hir::*;
-pub use hir_id::*;
 pub use lang_items::{LangItem, LanguageItems};
 pub use stability::*;
 pub use stable_hash_impls::HashStableContext;
diff --git a/compiler/rustc_hir/src/stable_hash_impls.rs b/compiler/rustc_hir/src/stable_hash_impls.rs
index ecc608d437b..16e8bac3d8a 100644
--- a/compiler/rustc_hir/src/stable_hash_impls.rs
+++ b/compiler/rustc_hir/src/stable_hash_impls.rs
@@ -5,7 +5,7 @@ use crate::HashIgnoredAttrId;
 use crate::hir::{
     AttributeMap, BodyId, Crate, ForeignItemId, ImplItemId, ItemId, OwnerNodes, TraitItemId,
 };
-use crate::hir_id::{HirId, ItemLocalId};
+use crate::hir_id::ItemLocalId;
 use crate::lints::DelayedLints;
 
 /// Requirements for a `StableHashingContext` to be used in this crate.
@@ -15,25 +15,6 @@ pub trait HashStableContext: rustc_ast::HashStableContext + rustc_abi::HashStabl
     fn hash_attr_id(&mut self, id: &HashIgnoredAttrId, hasher: &mut StableHasher);
 }
 
-impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for HirId {
-    type KeyType = (DefPathHash, ItemLocalId);
-
-    #[inline]
-    fn to_stable_hash_key(&self, hcx: &HirCtx) -> (DefPathHash, ItemLocalId) {
-        let def_path_hash = self.owner.def_id.to_stable_hash_key(hcx);
-        (def_path_hash, self.local_id)
-    }
-}
-
-impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for ItemLocalId {
-    type KeyType = ItemLocalId;
-
-    #[inline]
-    fn to_stable_hash_key(&self, _: &HirCtx) -> ItemLocalId {
-        *self
-    }
-}
-
 impl<HirCtx: crate::HashStableContext> ToStableHashKey<HirCtx> for BodyId {
     type KeyType = (DefPathHash, ItemLocalId);